Why is the expansion of the universe accelerating? Even after two decades of research the answer is still mysterious, but the questions have become clearer
- Almost 20 years ago scientists discovered that the expansion of the universe is accelerating. The cause of this acceleration is called "dark energy".
- Although intensive research has been conducted in the field since the discovery, even today we do not know the nature or origin of dark energy. But this research revealed several questions: Why is the magnitude of dark energy so much lower than theory predicts? What does this low size mean for the future of the universe? Will the existence of dark energy lead us to the conclusion that our universe is just one of infinite universes within a multiverse?
- Through several experiments that have been conducted recently and experiments that are expected to be conducted soon, the scientists hope to get answers to these questions in the coming years.
The universe is growing every second: the galaxies are moving away from each other, the galaxy clusters are moving away from each other, and the empty space itself is expanding. These facts were already known in the 20s, when Edwin Hubble and others discovered that the universe was expanding. But not long ago astronomers discovered that the expansion process itself is accelerating, meaning that the expansion rate of the universe is increasing, so that at this moment the galaxies are moving away from each other faster than they did a moment ago.
This is the shocking conclusion reached by one of us (eyelash) in 1998, when he edited, together with a group of researchers that he jointly led with Brian Schmidt From the Australian National University, measurements of distant supernova explosions. The findings of Rees and Schmidt's group coincided with the findings of another group, led by Sol Perlmutter from the University of California at Berkeley, which used a similar method and also published the results of its research in the same year. The conclusion was inevitable: something is causing the expansion of the universe to accelerate. But what is this something?
We call that mysterious factor that creates the force of repulsion that stretches the space by the name "dark energy". After nearly two decades of research, not much more is known about the physical nature of dark energy than it was 18 years ago. In fact, the results of the latest observations even complicate the picture even more, because they differ from what the leading theories predicted.
We are therefore left with some pressing questions: What is dark energy? Why is it much weaker than the simplest theories predict (yet strong enough for us to notice its effects)? What will be the effect of dark energy on the future of the universe? And finally, is it possible that the strange properties of dark energy imply that our universe got its properties at random, meaning that our universe is actually just one of a vast collection of other universes, each with different properties and with a different intensity of dark energy?
There is currently an onslaught on all fronts to understand the nature of dark energy and there is a good chance that several observational projects will soon bring significant progress. During the next decade we hope to be able to start answering the questions asked here and crack the puzzle of cosmic acceleration - or we will have to leave some puzzles unsolved for an unknown period of time.
What is dark energy?
Scientists have made several hypotheses about the force driving the acceleration in the expansion of the universe. The leading hypothesis is related to the properties of the space itself. According to quantum theory, empty space is not "nothing" but is teeming with activity: countless pairs consisting of a "virtual" particle and antiparticle are spontaneously created and ionized in a process that takes an infinitely small amount of time. Strange as it may sound, the sea of these temporary particle pairs carries with it energy, and energy, just like mass, produces gravitational force. But unlike mass, energy can create both an attractive gravitational force and a repulsive gravitational force, depending on whether the energy pressure is positive or negative. According to the theory, the energy pressure of empty space is negative and therefore it can be the source of the repulsive force of gravity that pushes the acceleration of the expansion of the universe.
This idea is equivalent to the cosmological constant that Einstein added to the equations of his general theory of relativity, which represents a constant energy density that is spread throughout space. As its name suggests, the hypothesis of the cosmological constant assumes that the density of dark energy is constant, i.e. does not change, in space and time. So far, the astrophysical findings we have are well explained by the cosmological constant hypothesis, with only minor deviations.
An alternative explanation is that the dark energy is a fundamental energy field in the universe similar to the ether in Greek philosophy (the ether was the fifth element in Greek philosophy, the one that makes up the sphere of the upper worlds, those beyond the earthly spheres that consist of the four classical elements). This assumed field is present at every point in space and gives it properties that resist gravitational pull. Fields are a familiar thing in physics: the familiar forces of electricity, magnetism and gravity are described using fields (although these fields are created from sources with a definite location, such as particles, as opposed to the assumed energy field whose sources are scattered throughout space).
If the dark energy does originate from a field, its intensity can change over time. In that case, the intensity of dark energy may have been stronger or weaker in the past, and therefore may have had different effects on the structure of the universe at different times. It is also possible that future changes in the intensity of dark energy will lead to changes in the evolution of the universe. In a version of the dark energy field theory known as the freezing field model, dark energy changes more and more slowly as time passes. In contrast, in a version of the theory known as the melting field model, dark energy changes slowly in the early stages of the universe and then changes faster and faster as time passes.
There is also a third possibility for the origin of the acceleration of the expansion of the universe: there is no dark energy, and the ever-increasing rate of expansion of the universe originates from physics that is not explained by Einstein's theory of gravity (general relativity) because it is incomplete. It is possible that on extremely large scales, such as when it comes to the size of galaxy clusters or even the entire universe, gravity works in a different way than the current theory predicts. Several physicists have presented interesting theoretical ideas describing such behavior of gravity, but there is no consistent theory that explains all the observations, so for now dark energy seems to have the upper hand. (Earlier ideas, such as that cosmic acceleration is the result of an uneven distribution of matter in the universe or of geometrical defects in the structure of space itself, are inconsistent with the observational data.)
Why is dark energy so weak?
None of the proposed explanations for dark energy are satisfactory. For example, the cosmological constant hypothesis predicts that the power of dark energy should be much greater than it really is. When we simply sum up the energies of all the quantum states in which those pairs of virtual particle and antiparticle that we mentioned earlier can be found, a result is obtained that is more than 120 orders of magnitude larger than the size observed in reality. If you do the calculation while taking into account theories that have not been confirmed by empirical observations, such as, for example, supersymmetry - a theory that assumes that for every particle we know in the universe there is a corresponding heavier particle that has not yet been discovered - you get a lower result, but still with a difference of tens of orders of magnitude relative to the measured size. So if indeed the origin of dark energy is in the energy of empty space, the question arises as to how the energy of empty space is actually so tiny.
The theory according to which dark energy originates in a fundamental energy field also fails in this regard. The theorists who came up with the theory simply assume, without providing any explanation for their assumption, that the minimum potential energy of the energy field is very low, so that the total amount of dark energy that is scattered throughout the entire space is also very low. Furthermore, this theory requires that, apart from the repulsive force of gravity, the other interactions between the proposed energy field and all other things in the universe be minimal, and this is a requirement that is difficult to explain. These problems make it difficult to include the dark energy field hypothesis within the accepted models of particle physics.
What does this mean for the future of the universe?
The properties of dark energy will determine the fate of our universe. For example, if dark energy is indeed the energy of empty space (the cosmological constant), the acceleration will continue forever. As a result, in about a trillion years, all the galaxies that are not the nearest neighbors of our galaxy (that is, the local group of galaxies, which in this time frame will have already merged into one huge elliptical galaxy) will move away from us at a speed greater than the speed of light, and therefore we will not be able to see them. Even the cosmic background radiation - that primordial twilight light left as a remnant from the Big Bang - will stretch to wavelengths that are longer than the entire observable universe, so that we will not be able to discern it. According to this scenario, we live in a very cheap time, because we still have an excellent picture of the universe.
If, on the other hand, the dark energy is not the energy of empty space but the energy of some mysterious field, then the whole future is open. It is possible that eventually, depending on how the field develops, the universe will stop expanding and then begin to collapse in on itself until it shrinks to the dimensions it started with in the Big Bang. Alternatively, it is possible that the universe will come to an end in a "big rift" where all the complex structures in the universe, from galaxy clusters to atoms and atomic nuclei, will be torn apart by the violent expansion of dark energy. And the first scenario we drew here, where the universe accelerates forever until it "freezes to death", is also possible in the case of a dark energy field.
An alternative theory to the force of gravity, if it turns out that there is a need for one, will also allow several scenarios for the future of the universe, depending on its physical details.
Is it possible that we live in a multiverse?
Since most theoretical physicists believe that the cosmological constant is the correct explanation for dark energy, its weak strength becomes a puzzle to be explained. Steven Weinberg from the University of Austin in Texas realized that there was a problem with the tiny size of dark energy even before the fact that the universe was accelerating was discovered. As a solution to the problem, he proposed a new model in which the size of the cosmological constant is not determined by the fundamental laws of physics, but is a random variable that takes on different values in different universes. In other words, our universe is just one of countless universes in a multiverse (multiverse), so the value of the cosmological constant that exists in our universe is purely coincidental. In other universes, there may be cosmological constants with much higher values, but in these the repulsive force of dark energy is so strong that it is not enough for matter to merge into galaxies containing planets and life. Since we exist, Weinberg concluded, it is clear that our universe must be one of those universes that can contain life, that is, a universe with a small cosmological constant. This idea, which was later developed by researchers such as Alexander Vilenkin from Tufts University, Martin Rees from the University of Cambridge, one of the authors of this article (Livio) and others, called by name The anthropic principle (Anthropos in Greek is man).
Besides the explanation for the weakness of dark energy, there are other reasons to suspect the existence of a multiverse. According to the theory of cosmic inflation, the universe underwent a tremendous dimensional expansion during the first fraction of a second of its existence. Vilenkin andAndrey Linda, the latter from Stanford University, showed that from the moment cosmic inflation begins, it occurs repeatedly and thus creates an infinite collection of "bubbles", each of which is a separate universe with its own unique properties.
It seems that multiverse is also a prediction of String theory, the same theory that is the best candidate we have for unifying all the forces of nature. Calculations performed by Raphael Bosso and Joseph Polczynski and based on a version of this theory called M theory, showed that there may be 10 to the 500 universes, and each of these universes is characterized by different values of the constants of nature and even by a different number of dimensions Spatial.
But it must be admitted that even mentioning the name multiverse raises the blood pressure of certain physicists. This idea is hard to accept and even harder to test experimentally. It is possible that in this way we have reached the end of the road of the scientific method as we know it, because this method demands that scientific hypotheses can be tested through experiment or observation. However, it is also possible that the multiverse hypothesis produces predictions that can be confirmed or refuted. For example, some models of the multiverse predict that the shape of space-time has some curvature that may be observable. Another possibility, although it must be admitted that it is unlikely, is that the cosmic background radiation has ripples that testify to the collision of our universe, even when it was a bubble, with another bubble.
find answers
The best way we know to begin to understand the nature of dark energy is to measure the ratio between the pressure it exerts (how much it pushes through space) and its density (how much of it there is in a given amount of space). This ratio is known as the equation of state parameter and is denoted by the letter w. If the dark energy is the void energy, then w will be constant and its value will be minus 1. On the other hand, if the dark energy arises from a time-varying field, we would expect to find that the value of w would be different from minus 1, and that it evolves during cosmic history. Alternatively, if the observed acceleration forces us to modify Einstein's theory of gravitation over vast distances, we would expect to find an inconsistency in the magnitude of w when observing the universe at different scales.
Astronomers have come up with some clever indirect ways to measure the pressure and density of dark energy. As a repulsive force of gravity, dark energy acts against the normal force of gravity, which attracts every mass in the universe to every other mass, and is therefore a resistance to the formation of large-scale structures, i.e. galaxy clusters. Therefore, by examining how these clusters grow over time we can infer what the strength of dark energy was at different points in time in the past. We do this by using a phenomenon called Gravity drainage - A valve of the clusters bends the light coming from galaxies behind them. The size of the light curvature allows us to deduce what the clusters are. This is how we measure the mass of clusters located at different distances from us and then we can know what the frequency of massive clusters was in different cosmic periods. (Since light takes time to reach us, the farther away the cluster is viewed, the earlier it is.)
We can also measure dark energy by looking at the variation in the expansion rate of the universe over time. By observing celestial objects located at different distances and measuring the red shift of the light they emit - that is, how much the wavelengths of light have been stretched by the expansion of space - we can learn how much the universe has expanded since the light began its journey from the observed objects. This was exactly the method with which the two groups of researchers discovered the cosmic acceleration. The groups measured the redshift of type Ia supernovae (the distance to which is matched to their brightness and therefore known with high reliability). A slightly different version of this method is to measure the observed magnitude of fluctuations in the density of galaxies in space. These oscillations, known as acoustic baryonic oscillations, are another reliable measure of distance and they also make it possible to follow the expansion history of the universe.
So far, most measurements of w have yielded a value close to minus 1 up to 10%. These results support the cosmological constant as an explanation for the accelerating expansion of the universe. Recently, a research group led by Reese used the Hubble Space Telescope and the supernova method to study the intensity of dark energy 10 billion years ago and found no different value for w at that time.
However, it is important to note that during the last few years some hints of deviation from the predictions of the cosmological constant hypothesis have been discovered. For example, from a combination of measurements of the cosmic background radiation (which gives us a measure of the total mass and energy of the universe) from the Planck satellite with measurements of gravitational decay, a value for w is obtained that is more negative than minus 1. ObservationsA panoramic survey telescope, who used more than 300 supernovae to measure the cosmic expansion, also indicate a value of w smaller than minus 1. Very recent observations of acoustic baryonic oscillations of bright distant galaxies called quasars suggest that the density of dark energy increases with time. And finally, there is a small difference between local measurements of the expansion rate of the universe today and the early expansion rate as measured in the cosmic background radiation, and this difference may indicate a deviation from the prediction of the cosmological constant. But as fascinating as they are, none of these results is conclusive proof of the failure of the cosmological constant model. Information obtained in the near future could confirm these findings or refute them by showing that they are due to systematic errors.
These days, work is being carried out that will lead to a 100-fold improvement in the accuracy of the measurement of dark energy during the next decade. New projects such as the dark energy survey (DES) which began in 2013 and the Large Synoptic Survey Telescope (LST) expected to start operating in 2021 will gather better information about large-scale structures in the universe and the expansion history of the universe. the telescope WFIRST-AFTA NASA's is a 2.4-meter space telescope that is planned for launch in the mid-20s of this century and will look for supernovae and distant acoustic baryonic oscillations as well as search for gravitational quenching. The launch of the space mission Euclid of the European Space Agency is currently planned for 2020. The mission will use gravitational perturbation, acoustic baryonic oscillations and redshift distance measurements to galaxies to determine the XNUMXD distribution of galaxy clusters.
And finally, we can test new theories of gravity through measurements inside the solar system. There is a method to measure the distance to the moon with astonishingly high accuracy (using laser reflection from mirrors placed there by Apollo mission astronauts). This method can be used to check if there are tiny deviations from the predictions of general relativity. In addition, sophisticated laboratory experiments will look for deviations from the known laws of gravity. The next few years will be crucial for dark energy research. We are hopeful that real progress will be made toward finding answers to questions about the accelerating expansion of the universe. These answers will tell us nothing less than the future of our universe.
119 תגובות
Yehuda Sabdarmish
Happy to inform you that they have found gravity pushing particles in the curd.
Miracles
This software simply knows you so well and it knows that you are just waiting for comments like Michael Assolin's to start another long and pointless rant that it has heard so many times from you that it just got fed up and decided to block you. 🙂
my father
right. I remember a time a few years ago when there were many spam messages on the site. What surprised me was that I did not find anything suspicious in my response...
The Eximet software is wonderful - it filters the responses as it sees fit. But it's better for good comments to be blocked for a few hours than for spam comments to flood the articles.
my father
Avi Belisovsky
Why is my comment blocked?
Michael Assulin
So you're saying it's better to study "zohar" instead of looking for a cure for cancer?
You will not come to the truth with your meager strength, you will learn the Torah of Israel and the answers are found in the pages of the Talmud and especially in the Holy Zohar which was written about two thousand years ago before any name of scientist you know. Invest in studying the Zohar and maybe if you have enlightenment you will discover that the world is led by the one who said and the world was. There is a creator of the world and all his secrets have been revealed to his wise men.
Albanzo
I do not agree with you that science can treat "nothing". And I'm not talking about the "nothing" of Lawrence Krauss, but about nothing that existed if there was before there was a universe. Nothing that doesn't also have laws of physics.
Yehuda
If you argue like this in court, then the judge will definitely agree! Then, he will politely explain that he also has no choice and for exactly the same reasons he is throwing you in prison for two years.
rival
I claim that mine and the dog have the same "free thought". If you ask "is it possible to make a reduction from free thinking to physics" then my answer is yes. But it doesn't help us understand the world. I will give you four analogies to explain my point.
The first is heat. There really is no such thing - temperature is the average speed of the particles. So instead of measuring a child's temperature, we will measure the average speed of his body particles.
The second is thermodynamics. Let's throw away the second law, because at the particle level there is no such law at all.
The third is the laws of nature. Natural law is not a real thing. There is no law of conservation of energy or law of conservation of momentum. We use these two laws to calculate the behavior of billiard balls after an elastic collision, but their motion is not the result of their necessity to "follow the laws". Kepler's laws do not require the planets to move in ellipses. The laws of nature, like the models behind them, are very convenient tools for understanding the world, but they do not explain the world.
The fourth example is ... the whole world. No chairs, mountains and razors. There are only atoms. Instead of a chair, a description of all the atoms that make it up from their height and speed is given. And there is no pain, love or hunger - there are only electrical signals in the brain. Not exactly useful.
So you agree with me that this is not a good way to understand the world. We're talking about their concept from the worlds of sociology->psychology->physiology->biology->chemistry->physics, and we're not just talking about physics, right? So the same goes for "free thought".
Think of the legal world. It is convenient for us to throw a thief in jail because he chose to rob a bank. But, we could invest thinking and examination, and understand the motives for the crime, and understand that that person acted from motives that would push any other person to commit the same crime! If you think about it - why do we put a person in prison? There are several reasons, one of which is notification. One of the reasons we don't all steal is the fear of punishment. Note the correlation between the speed of travel on the roads and the presence of the police....
It was a bit long, but I don't think there is an argument between me and you on this issue.
Yehuda
Please - try to refer to what I wrote. It's a simple thought experiment. I don't understand what you are afraid of….
rival
I didn't think about the mechanistic physical opinion of the court..
It is better that I postpone the commission of my crimes...
Yehuda,
The important question is what is the truth, not what seems more logical or nice to you. Because every decision we make is physically mechanistic, so you really have no control over crimes you might commit, but in the event that you claim this in court, then he will also be able to answer you that he also has no control over the decision to punish you, and this is also the result of mechanistic physical thinking.
Yehuda,
The important question is what is the truth, not what seems more logical or nice to you. Because our decisions are physical and mechanistic, so you really have no control over crimes you may commit, but in the event that you claim this in court, then he will also be able to answer you that he also has no control over the decision to punish you, and this is also a result of mechanistic physical thinking.
to the opponent
The important question: am I responsible for my actions or in the next crime I commit (perhaps) I can claim that:
I am not guilty because my thought of crime stems from something physical and mechanistic for which I am not responsible and it was determined in the big bang. I do not believe that there is a court that would accept such an approach. At best he will send me to the hospital.
So please respond gently or is it something physical and mechanistic for you too?
Good day opponent
Yehuda
Miracles,
Do you really think that your dog has a free choice from which plate to start eating? Are you claiming that his decision is not physically mechanistic but stems from something else?
Yehuda,
What made you conclude that our thought arises from something that is not physically mechanistic? How did you get to that?
Lenice
I didn't answer you about the concept of "soul" because I knew the problems with it. What is a soul?, someone already said (Descartes?) "I think, that means I exist" so maybe the existence of a thought is the soul? That's why, in my previous response, I brought the concept of "thought" instead of "soul". That's why you don't have to complain about me and Rafael that we don't respond to a concept that we don't understand. But from this to decide that the soul does not exist?, in my opinion, this is an excessive decision. I for one decide that there is a soul in my nose, at least out of a free choice no less than your dog's free choice between two plates. Maybe my answer will still appear to you as evasive but this is the most I can do.
All the best
Yehuda
http://yekumpashut.freevar.com/
to Albenzo
I disagree with your opinion expressed in the second section which is a hymn to the human ability to determine facts.
Sorry, but I have a different opinion, and I will explain my words.
We can establish any law we want, but, will the law be acceptable?, only one thing will convince us and that is the measurements we measure in the field. I can decide that gravitation works according to the distance and not according to the square of the distance. Will the law be admissible? Of course not, it simply will not pass the measurement test. And here we come to the problems of the measurements:
Most extreme borders are closed to them!
To say that mathematics takes care of them is a beautiful and encouraging thing, but sorry Albanzo, we take care of physics and physics has limits:-
Unlike mathematics, in physics you cannot measure infinitely. You can't make measurements on singular points, black holes with huge masses, and so on. Therefore, you cannot confidently determine anything about the aforementioned extreme limits. That's why when I read a sentence that "gravitation is defined for every mass in the universe", sorry but it makes me laugh, no one has measured it and tested it. There are no measurements at infinity. What we can do is to "gnaw" without knowing, to work to increase the measurable limits. No inductive reasoning holds here. From what we have measured with confidence we only have... what we have measured (philosopher David Hume). Beyond that, everything is only with a limited guarantee. No full confidence in untested things.
So, some modesty, the big bang?, started with a dot? According to the existing laws of physics 13.8 billion years after him? Maybe, nothing is certain. Sorry, but it is what it is!
A gentle response is required
Good Day.
Yehuda
Yehuda
I'm not talking about free choice, but about soul. I cannot define what free will is, and I have no problem saying that it exists. If I serve two plates of food to my dog, then the dog will freely choose which plate to start eating from.
But, in my opinion, the soul has no place, because it requires something that we see does not exist.
Do you notice that no one is responding to the question itself? I mean, no one finds fault with this claim? Even Raphael agrees with me, against his (free?) will.
for miracles
Don't think that my words in my previous response are establishing a position on this age-old issue of: "What is thought?". Is she the one who activates us, or are we just another machine-like collection that operates according to the laws that were instilled in it in the past, that operate based on the laws of physics and nothing else. No free choice." It's as if my reaction to this science site was already determined in the Big Bang. I wouldn't want such a universe but it's hard for me to decide what kind of universe we are.
I of course behave as you think, I have never included anything non-scientific in my comments. It's hard for me to even introduce concepts in quantum theory like particles passing through two slits at the same time although I know it seems like that's the explanation. I don't have an alternative explanation for various quantum problems (at the moment)
And regarding the example of the machine you brought, I would think that it decides and acts just like you and not looking for demons that operate it. The religious sages in Judaism were also aware of this physical philosophical problem and stated: "Everything is determined and permission is given", meaning they understood that they must leave something that is a kind of free choice. In Islam the rule is "everyone is a kind of Allah" and I am not sure that they leave the free choice, but my knowledge of Islam is small.
For Albenzo - a separate response (in preparation).
Please respond gently
Yehuda
Raphael,
1. This is exactly what I am trying to explain - that except in certain extreme situations, there is no such thing as "what remains outside the visible universe". We still do not know exactly what the dynamics of space are throughout the life of the universe, but apart from extreme situations where the universe expands faster than light forever starting from a certain point, every point in space will be in the visible universe at some point (neglecting theories about parallel universes, etc.).
2. Of course we know how to take care of nothing and infinity. All you need is to learn a bit of group theory, and a little complex analysis won't hurt. I don't know who told you that we don't know, but mathematics has been dealing with these concepts for hundreds of years with great success. All theories in the universe are tested in the same way - we see what their implications are for the measurable quantities in our world, and perform the measurements. Sometimes it can be measured directly and sometimes indirectly. Obviously, a theory according to which the bang started at a singular point and before which there was no temporal coordinate (or space for that matter) will have to be tested indirectly by creating cosmological predictions and testing them. But there is nothing wrong with an indirect test - after all, even the fact that a particle can be found in two points at the same time (quantumly) we only know how to test indirectly, and many, many other things that are enshrined in the foundations of science as we understand it and are at the basis of various technologies that prove themselves too a day.
Yehuda
I wrote something that I think is very important "If every particle in my body moves according to the laws of physics - this means that no "non-physical" force acts on the particles of my body."
Raphael did not address it, because it invalidates what he believes in. After that, he changed his mind and claimed that what is important here is why there are laws of physics. He probably realized that this did not help his position, and then claimed something like "He who has a soul knows that he has a soul and therefore has a soul".
Maybe you want to address what I said? I will describe it in a simple way. I look at a Rube Goldberg machine and see that every part of the machine moves according to Newton's laws...springs, weights, gears and so on. Please note - I am not trying to understand how the machine works and what it even does, and I am not referring to the origin of the machine or the purpose of its construction. I just look at all its parts - and they move according to the laws of physics. Is it not fair to think that there is no mystical force / Maxwell's soul / demon / ghost that works inside the machine, or even externally on the machine?
Referring to the quote "thought is a physical thing".
There is the symbolized "table", and there is the symbol "table", and there is the relationship between them.
The relationship between signifier and signified is neither the signified nor the symbol. He does not exist by himself. He is not created by himself.
It is not the physical relationship between the symbol "table" and the table itself.
It is not measurable and yet exists. It has no effect on the world, but it exists. It does not contradict the laws of physics and yet it is known to exist. It was created, although it was not created from the laws of physics.
This relation is the meaning. Meaning is not a physical object and cannot be derived from it.
What is the thing that awaits every possible measurement and that itself cannot be measured?
Miracles
Why do you think anyone who disagrees with you is irrational?
The subject is science and philosophy and the best ancient sages and medical people have been discussing it since time immemorial, there are sides here and there but your approach is not fair, you are simply trying to dominate your opinion on Raphael whose opinion and explanations are at least as good as yours. It really doesn't make him irrational. So please don't fight and shake hands, don't forget that this is just science.
All the best and good night and please respond gently
Yehuda
Raphael
You reinforce in me the thought that there is no reason to have a rational discussion with an irrational person. No offense, but I think your thoughts are irrational. You hang on every word and don't try to understand what I'm saying. I'm sorry it's like that.
I feel like I've exhausted myself and can't go any further at this point. Bye.
Raphael
Again, you are assuming what you are trying to show. Please, try to understand what I am writing.
Let's start with a dead person. How is death determined? 1) "lack of soul"? Or, maybe 2) "lack of signals in the brain"? I ask seriously - how does a religious person decide that a person is dead and that it is time to bury him? And after you find an answer, ask yourself - how is it different from determining death for a dog?
Now, I realize we have gone back…. Are you claiming that there are signals in the brain that we cannot know the source of?
Rafael, stop disrespecting what other people tell you. You only underestimate yourself.
Miracles,
It's just amazing how you roll your conclusions and jump from matter to matter in the blink of an eye.
After all, the physical brain is physical. The thought is not a physical thing but it affects the brain and activates it, therefore when you perceive the signals from the brain then you do not perceive the thought (because it is a non-physical thing) but its effect on the physics of the brain.
"Why" is not "for what purpose" but simply "why" why a small particle will behave according to a certain law.
Regarding this - "If I take a group of particles and put them together just like the brain, and give each particle the right speed, then I will get a thinking brain. I understand you agree to that, right?”
Absolutely not true. Take a person who died just a second ago. Everything is there except his soul and his brain is completely dead because there is no one to activate it.
Raphael
Nice - so we agree that there is nothing non-physical about the brain, right? And the question is what causes the laws of physics?
Beautiful! So you have to agree that there is no such thing as a human soul. Maybe there is a creator who caused the laws and created the particles in the brain. Maybe. But - if I take a group of particles and put them together just like the brain, and give each particle the right speed, then I will get a thinking brain. I understand you agree with that, right?
Yehuda - do you agree to this?
Now to the question of why. "Why" means "for what purpose". And so the question requires someone who has a goal. In our case - you must assume that there is a God for the question to have meaning. That is - you have assumed what you are trying to prove.
Do you agree with what I wrote?
And if there is a creator and it is permissible to ask why, then I also have some questions. Why do small children have such terrible diseases? Why do most people in the world die in agony? Why do most animals in the world die in agony? Why do you even die? Why is there not enough fresh water in the world? Why are religious people no longer healthy?
Raphael - Why should I believe in the same God that you believe in? Why are Christianity and Islam bad in your eyes? What is wrong with believing in many gods?
Let me give you a point to think about (and don't conclude from this my opinion!). Jesus said that the Sabbath was created for man, not man for the Sabbath. Therefore, he is allowed to enjoy Shabbat however he wants. In the Torah it is written to kill those who work on Shabbat. So Jesus was such a negative figure in your eyes? (And again - I'm not saying that Jesus wasn't a negative person, or even existed...).
Yehuda
I think thought is a physical thing. A thought is ultimately a collection of electrical/chemical signals - they can be seen and even influenced. Today it has come to the point that there are games that are controlled with the help of thoughts. We already know how to read minds - we can connect you to a device and know what color you are thinking about, for example. And we know drugs that affect at a higher level, and change a person's character (LSD, alcohol and so on).
We know that there are areas in the brain where different thinking operations are carried out, and this is an extremely important tool in diagnosing brain pathologies.
Yehuda - A thought is no less physical than an electron. There is nothing "spiritual" or mystical about thoughts.
A comment I wrote last night was sent and censored as dark material for not being unjust
I will try to restore part of it.
for miracles
I actually agree with Raphael's opinion. Maybe the example we are taking of "soul" is a bad example, I would prefer to talk about the concept of "thought" is not a physical thing and yet it causes a physical result for example of writing this comment. So, contrary to your opinion, parts of my body moved according to the laws of physics and no physical force acted on me. A problem that I don't know how to solve but I also don't agree to deny it,
Please respond gently and certainly not physically
Yehuda
Miracles
When you wrote "explain the matter" you meant "from a logical point of view" because if a particle behaves according to the laws of physics you still have to explain why the "particle" is obliged to behave according to the laws of physics and this "why" is another thing that is outside the boundaries of science. But as mentioned, I am religious, so there is no point in arguing with me.
Waiting for Raphael. Miracles, you are more than welcome to read when my father releases from the cellars
Raphael
The "soul" is apparently nothing more than the result of the cooperation between the brain and the rest of the body.
There is nothing metaphysical about it.
Complexity of connections in the brain creates a unique experience...
Nissim and Raphael
I'm sorry Nisim, but in this case I agree with Raphael and I don't see that Raphael doesn't take your words into account. You are simply stating things that are not proven. Maybe the use of the term soul is not clear, but what do you think about the use of the term "thought". This thought that we use for example here on the science website is abstract and yet it has physical results of writing for example and even activating Yehuda for a response. You can be surprised that science deals only with physical things, but this is not a definition of science, a scientific concept is one if you can show a way in which it can be developed (this is what the philosopher Popper said) and now we will take a number of concepts that we deal with and they are: God, thought, dark matter and dark energy. Are they scientific?? Well God is not scientific. point. It cannot be refuted. Thought is generally a scientific concept, because it can be disproved. Regarding dark matter? Is it possible to show a way to flower it? We are provided as above with the dark energy... So maybe the dark matter and the dark energy will be added to God and it will be determined that they are not scientific.
Please respond gently
Yehuda
Raphael
I understand that you have no intention of addressing my words. You're just walking around trying to say something that sounds smart. Take the word "logic" out of gear, and you continue to attack me for it.
It is difficult to have an intelligent discussion with a religious person. They know everything.
Raphael,
Usually not much comes out of these discussions in the sense that no one changes sides, yet I will try to direct you to the strongest argument I know about the non-existence of a soul: watch the first twenty-two minutes of Sean Carroll's lecture. He builds an argument against the existence of a soul based on quantum field theory and its great success in predicting the world and what we know about interaction between particles. I can summarize his arguments but he is much more convincing than I am
https://m.youtube.com/watch?v=xv0mKsO2goA
If you prefer to read,
http://www.preposterousuniverse.com/blog/2010/09/29/seriously-the-laws-underlying-the-physics-of-everyday-life-really-are-completely-understood/
And then that
http://www.preposterousuniverse.com/blog/2011/05/23/physics-and-the-immortality-of-the-soul/
Miracles
"We at the site of knowledge" (all rights reserved to Yehuda) must be precise in our speech. Your logic really doesn't make sense because even those who think there is a soul knows and is clear to him that the soul drives the body according to the laws of the body and the (close and imperfect) parable in this is the driver driving the car according to the laws of the car. If you want to talk in terms of logic to prove that there is no soul you will not succeed. And I also don't understand why it's so important to you.
Raphael
Please pay attention to what I write and don't get hung up on every word. We are not in kindergarten. I will explain again:
If every particle in my body moves according to the laws of physics - this means that no "non-physical" force acts on the particles of my body.
Do you really not understand what I'm trying to say?
Miracles
logic? God forbid! Logically, a particle cannot pass through two slits at the same time!
Why are you mixing logic with science?
Raphael
from logic. If every particle in my body moves according to the laws of physics - this means that no "non-physical" force acts on the particles of my body.
Miracles,
"If there was such a thing - the meaning is that we would see something happening in the body that contradicts the laws of physics"
Where did you get it from?
Raphael
The soul is a good example. If there was such a thing - it means that we would see something happening in the body that contradicts the laws of physics. We do not see any movement of molecules or any electrical signal that cannot be explained physically. In addition - we know how to control our muscles and our thoughts in a good way. Therefore - with the highest probability it can be assumed that there is no soul.
Miracles
"The object has a physical effect, therefore the object is physical..."
How did you reach that conclusion?
For the purpose of the example, let's assume that there is a soul (something we cannot prove or disprove according to science) and the soul activates the brain, which is a physical thing. Is this an impossible thing?
Raphael
Because - if something has an effect on the world, then this effect is physical, and therefore the object has a physical effect, and therefore the object is physical....
There are two types of possible phenomena - those that depend only on history (deterministic phenomena, Laplace's universe), and random phenomena. I don't think anyone has observed a third phenomenon - a phenomenon that is neither random nor a result of history.
miracles,
"Note something essential here - these objects have no effect on the world!"
how do you know that?
albenza,
2. How do you verify/contradict, for example, a theory that says that before the big bang there was nothing? Does science know what nothing is? I don't think so. Just as he does not know how to define infinity.
3. I agree with you that the more accurate definition of physical is that which can be tested for its effect on our universe by measuring
1. Even if there is a situation where stars return to the limits of the visible universe - still what remains outside the visible universe will also remain beyond the reach of science. We will never know what is beyond the "end of the universe" if there is such a thing.
Raphael
Not many years ago diseases were outside of science because there was no microscope. And just a few years ago, investigating the structure of matter was outside of science, because we had no way to see the trajectories of these particles. The acceleration of the universe was outside of science when you were a kid, because we didn't have accurate enough measurements. And as Albenzo said - what we don't know today happened in a tiny fraction of a second from the beginning of the big bang.
There are other dimensions to "outside science". For example "Did a red car drive after me yesterday". Science will never know that. We may also never know what Ahasuerus ate for dinner on his 30th birthday. So what do you want to conclude from this?
Albenzo wrote, "The only fundamental limitation that I can think of is the one that we agreed not to enter into - given that non-physical objects may exist in our universe (in the sense that I defined in my previous response, i.e. that it is not possible to examine their effect on our universe by measurement), science based on observations will not have A way to explore them forever. This will be an absolute limitation that stems from the way the scientific method works, as opposed to the soft or technological limitations we talked about earlier."
Notice something fundamental here - these objects have no effect on the world! They can certainly have the ability to observe our world, and it can disgust them that I eat shrimp at every opportunity - but they have no ability to influence me.
And note an important point - we have no ability to know anything about them - including whether they exist or not! And in particular - we cannot deduce their existence from our lack of knowledge about the world.
And on the other hand - if they have the ability to influence our world, then these objects are physical...
Yoav
I can't have a discussion on topics I don't understand. I do know that the accepted theories are very well-founded, and I think you need a very good reason to reject them. I understand that we have no idea what "dark energy" is, and there is definitely room for updating our theories. If a certain scientist has a revolutionary theory that abolishes everything that exists just to solve the problem of dark energy or dark matter then he/she should come up with a very very good explanation for this theory. And if there is a good enough explanation - I don't think it would have been rejected by other scientists.
You said that light may be getting tired, so the conclusions about the expansion of the universe, and especially about the acceleration of this increase, may be wrong. I find it hard to believe that this theory is dismissed solely because it breaks conventions.
And in any case - I don't think there is a place to update the middle school physics books with every new idea. And I'm not sure that it is noted in these books that the Big Bang is a "Torah from Sinai." It bothers me much more that evolution is not taught in depth in school. There is no debate about evolution, and its importance to life is orders of magnitude more important than the correctness of string theory compared to the correctness of quantum gravity.
2. No, it is not true that what preceded the bang is outside the boundaries of science. As I said, at the moment we are not yet at a point where we can investigate this field observationally, but for example theoretically (if we simply assume for the moment that string theory is correct, for example, even though it has not yet been adequately tested experimentally) it is certainly possible to talk about the point of the bang and "what preceded her". I put what preceded it in quotation marks because, according to certain opinions, nothing preceded it (therefore there is nothing to investigate - it's not that there was something but we don't have access to it, it's that there simply was nothing, if you'll allow me to simplify a lot). According to other opinions, before the bang there was something else (for example a universe that expands and contracts cyclically) and then there is absolutely absolutely no problem to investigate what happened before the point of the bang. Any way you look at it, the Big Bang's limitation is purely technical.
3. I respect your desire not to get into this topic, nor am I interested in it, but I will comment that the definition of "physical is composed of particles" is not good. As you may know, in modern physics particles are not a fundamental object, but a phenomenon that sometimes occurs (for example, at the low energies in which our daily lives are conducted). The fundamental objects in modern physics are fields, and they are definitely not particles or composed of particles. They cannot be touched or placed in space. Today we certainly know how to deal - both theoretically and experimentally - with objects that are not composed of particles.
1. The universe is expanding at an accelerated rate right now (a very small acceleration), but we don't know how long it will last or how long it has been like this (again, forgive me for the abstraction - of course there is some information, but the expansion profile of the universe in general is unknown. It's not like it's in constant acceleration.) This is exactly what I meant by "neglecting the dynamics", in principle you can compare the speed of expansion of the universe and the speed of expansion of the visible universe (the speed of light) and see exactly how long it will take for each point to enter or exit the visible universe. The scenario you describe is a long-term scenario for constant acceleration, one that there is no reason to currently prefer over other scenarios. The exact answer - how long it will take for each point to enter (or leave) the visible universe depends on the information we don't have yet, and this is related to what I was trying to say - this problem, of being able to get frustrated only in the visible universe - is not a fundamental problem either. It does not limit science's ability to explore the world. At most, there may be a scenario in which there is information that will not be available to us today or in the future (in other words - we remembered too late to start observing the universe). But this is not a fundamental limitation of the scientific method.
The only fundamental limitation that I can think of is the one that we agreed not to enter into - given that non-physical objects may exist in our universe (in the sense that I defined in my previous response, i.e. that it is not possible to test their effect on our universe by measurement), science based on observations will have no way to study them forever. This would be an absolute limitation that stems from the way the scientific method works, as opposed to the soft or technological limitations we discussed earlier.
albenza,
2. I accept that we currently have a technical limitation that it may be possible to overcome in the future and get closer and closer to the Big Bang moment and perhaps to the Big Bang moment itself. But according to what you wrote, it is clear that what preceded it is outside the boundaries of science. did I understand correctly?
3. Physical is something that consists of particles, including light. Therefore we agree that science does not deal with them and has no tools to find out if they exist or not, or to predict their behavior. Regarding the question of whether their existence is a matter of opinion and belief or not - here I do not agree with you, but since here (as Yehuda said, "here on our site of science") we are talking about science only, so I do not want to engage in this and I know that you do not want to either. So let's leave that aside for now.
1. I did not understand what you mean by this sentence: "If we neglect for a moment the dynamics of space itself, all that is needed is patience, and in the end everything that exists in the universe will be within the visible universe." After all, the universe is constantly expanding in an accelerated manner and what is happening is exactly the opposite - galaxies that are today within the visible universe will in the future cross the limit of the visible universe and disappear forever. No Yes?
Finally, we will return to the beginning of your words ("Your examples are not good"). Are there or are there no limits to science? And if there is - could you give some good examples?
Raphael,
Your examples are not good. Not in order:
2. Our limitation to understanding the "moment of the bang" and what preceded it (if such a thing actually exists, it is not clear because of what I will explain in the following lines) is our lack of knowledge regarding quantum gravity. The Big Bang model can be tested back up to a certain point (very, very close to the point where according to the model everything is at a singular point), then it cannot be tested any further because we need a quantum theory of gravity. Today we still do not have one (there are candidates and a lot of research, but there is still no theory that has been tested in the laboratory). When there is a theory, we can certainly use it to study the universe closer to the moment of the big bang. Already within the framework of string theory (which we still do not know for sure if it is true or not) there are very good and interesting studies and ideas about the moment of the bang itself. But as mentioned, we still don't have the tools to test them experimentally. In conclusion - this is only a technical limitation that will be resolved as soon as we advance another step-two-three in our understanding of gravity.
3. It is not well defined. If by "physical" you mean "can be touched", then of course science studies non-physical things as well. Physics has a fantastic understanding of light, forces, etc. If by "physical" you mean anything that can be tested experimentally in our universe by observations, then yes - science cannot deal with them. But this is a bit silly because the scientific method is a method of distinguishing between true and false claims with the help of observations (in an extreme abstraction). That is, to say that science is limited to dealing with physical things is like saying that the group A has no intersection with the group of things not contained in A. It's more of a play on words than a claim about our universe, especially if you remember that while opinions differ on whether or not there are non-physical things (soul, God, etc.), by definition there is never any way to test if they exist. Therefore this question will forever be a matter of faith and knowledge.
1. It's a little more difficult, but also not accurate. The visible universe is defined by the part of the universe that is close enough to us that from the moment of the bang (or close to it) until now, enough time has passed for light from these regions to reach us. What is outside the visible universe is by definition things so far away that even at the speed of light from the moment of the bang until now, there is no possibility of interaction between us and them. The reason it's not really a "limitation" either, is first of all that the visible universe expands over time. Today a certain star is outside the visible universe, tomorrow it will be inside. If we neglect for a moment the dynamics of the space itself, all that is needed is patience, and in the end everything that exists in the universe will be within the visible universe (of course, the dynamics cannot really be ignored, but this can be expanded on by itself in ten responses). In addition, there can be indirect means by which we have interacted with parts of the universe that are outside the visible universe (for example, inflation contains such phenomena that result from the rapid-expansion from light in the early universe), so indirectly we can know certain things even about regions that we cannot see. Of course, like point 2, this is also technologically limited because our understanding of quantum gravity (which controls the expansion processes of the universe) is not yet complete enough.
Miracles
I will give you 3 well-known examples of the limits of science:
1. What is beyond the visible universe
2. What preceded the big bang and the big bang moment in general
3. Any entity that is not physical
Miracles,
It's a shame that you see the discussion as personal, the discussion should be conducted on the statements, and not as a kind of hand-off.
These questions concern me a lot, and I devoted a lot of myself to understanding and formulating my own answer.
If for you it's a battle of knights then it's a waste of time.
I brought arguments, and also mentioned the huge interests involved, again it's a shame that you chose to be offensive, and not address my claims, about the "fatigue" of the light for example.
Yoav
"Divine particle" sounds like something mystical. "Dark matter" may not be a very good choice either, the very name bothers Judah a lot. The name "big bang" is also problematic. The problem with these concepts is that people who are not experts in the field think they understand what it is all about. No one rules out Ritchie's tensor, or Cherenkov's radiation, because it sounds complicated….
I don't pretend to understand dark energy as such and I have no opinion on the subject. What bothers me is the audacity of people who don't understand more than I do, expressing a firm opinion on the subject, as if other scientists are a collection of charlatans and fools.
I really appreciate people who understand much more than me. And I am very surprised that people dismiss scientists because they are not skeptics…..but they are sure they know all the answers.
Yehuda,
I really enjoyed your response, only I think that a conversation with religious people about physics cannot be avoided, Leibniz and Newton were people with a very strong religious feeling, yet very decent, and separated their faith from their work. What is clear is that faith and science are water and oil and should not be mixed.
Miracles,
The need for dark energy comes from a huge inaccuracy of the theories you are so excited about. Dark energy is a huge, clumsy patch spread over the religious establishment's beloved Swiss cheese.
There is dizzying progress in science, especially in biology, and an incredible technological boom, but basic physics lives on from the remains of Einstein's work from over 100 years ago.
Your paragraph about the delicacies with too big a mouth is puzzling, and they wanted you to clarify it.
The Big Bang is a hypothetical event. And enough with the fake news, miracles.
Raphael
Another way to look at it is this: physicists have shown that there is no need for an external creator. Also, the chemists showed that there is no need for a creator to facilitate the formation of life.
It does not prove, but it shows that there is no necessity. Is it possible to contradict the existence of a creator? If you mean the creator from the model represented by the major religions - then in my opinion the answer is yes. I think the suffering of children rules out any possibility of a God loving man.
Raphael
I know no such limits. We may know for sure what happened then. The condition for this is that we find an explanation that works, and that this is the only explanation that can come into consideration.
There is a scientific principle, which of course is not a law, which says that if there are several explanations for an observation that we have no way of refuting - then we choose the simplest explanation.
So let's assume we find a single explanation. So - a religious person will come and say "God is also an explanation". Now, you have to choose the simplest explanation. Now - you have to choose the simplest explanation... And here you and I will probably not reach an agreement.
There really might be a limit to science here...
Miracles
According to the definition of the limits of science and physics, any hypothesis to explain what happened in the big bang will always remain a hypothesis that cannot be confirmed or contradicted. agree?
Yehuda
The scientific theories work under the most extreme conditions. For example - there are cosmic particles with the kinetic energy of a baseball at 160 km/h!!! These particles do not break the laws of physics, so we can assume that these laws worked for a very long time in the past, at least to the limit of those particles I mentioned.
What happened before that? God knows….
Yoav
The name "the divine particle" is a phrase of Leon Lederman who wrote:
"This boson is so central to the state of physics today, so crucial to our final understanding of the structure of matter, yet so elusive, that I have given it a nickname: the God Particle. Why God Particle? Two reasons. One, the publisher wouldn't let us call it the Goddamn Particle, although that might be a more appropriate title, given its villainous nature and the expense it is causing. And two, there is a connection, of sorts, to another book, a much older one"
Scientists "worship" dark energy and dark matter for three good reasons. One of them is that the existing theories explain with amazing precision what we see and you really need a good reason to throw them away (more than that - there is not a single observation that contradicts them). The second reason is that there is more than one evidence of these dark things (dark means that it has not been tampered with, and not something mystical). The third reason is that most of the theories that try to make these things disappear - do not give a good explanation for other phenomena (pushing gravity does not explain slowing down in time, the bending of light and so on. God does not explain the cruelty in the world and so on).
In the meantime, this scientific method has advanced us very nicely. I wouldn't rule her out because there are some scientists with too big a mouth.
Raphael
The Big Bang, like evolution, is an event, not a theory (theory in the sense of explanation, as opposed to practice). There are several hypotheses that explain what happened then. It is possible that one of the hypotheses is true, and it is possible that another hypothesis, which we have not yet thought of, is true. Therefore - there is no need for a Creator. Raphael - this does not mean that there is no creator!
The same goes for the formation of life - there are a number of existing hypotheses that explain how exactly it happened. Not necessarily one of them is correct, but again, we have shown that there is not necessarily a need for a creator.
It is permissible to assume that there is a creator - but if you come with a scientific approach then you will offer experiments that will show that you are right.
תיקון
- Religious opinion is not scientific because it can never be refuted.
We at the site of knowledge should avoid getting into arguments with people of religious opinion. A religious opinion is not a scientific opinion, so it is not our concern. It is not scientific because it can never be disproved. For example, when I showed a religious person proofs that the world has existed for over 6000 years, his answer was that God made these proofs so that despite the proofs we believe in his existence. With the method of the "great magician who is omnipotent" they overcome any proof that a religious person will bring, and will refute it. On the other hand, when I come up with an idea or a theory, I immediately come up with the ways in which it would be possible to test a refutation (popper) of a non-scientific God because it is not allowed to be disproved at all.
But this does not mean that I agree with everything accepted in science, for example I do not believe that the entire universe was ever concentrated in a singular point and in general, in my opinion, there are no singular points in the universe. In my humble opinion there cannot be a singular point because the laws of physics with the help of which it was determined and defined, have never been tested as correct in its environment.
Please respond gently
Good Day
Sabdarmish Yehuda
Miracles
Can you please calmly and briefly explain why you think the big bang makes the need for a creator redundant in your opinion?
I get the impression that you are talking about culture and not science. If you build a magnificent temple, and receive a sea of money, worship a statement that must not be doubted, investigate powers created in the fevered minds of the priests, and when the universe at the height of its insolence refutes the new theory, a new power comes into the world, and the flock of believers engages in it with zeal, then this is worship, Accompanied by magical words such as divine particle, big bang, superhumorization, dark energy, world of small things, etc. So I don't see rationality here.
But religious establishments that support huge sums everyone sees.
You have the right to call it science, you can sew dolls and stab them to hurt people who upset you (I hope I'm not one of them), and call it science, and decide that mathematical formulas are evidence.
I'd rather be a proud Ethiopian.
Yoav
My point is that there is no evidence for phenomena such as fairies, ghosts and life after death, not necessarily the same discussion of the monks.
There is a phenomenon that we do not know how to explain, and we called it "dark energy". The question is what to do with it. If you (a) try to disprove the need for this energy, and (b) try to develop models and perform experiments to understand, then you are doing science.
If you build a temple for it and charge money to enter then you are making a religion.
I don't think it's exactly the same thing.
I don't think physics and mathematics are two sides of the same coin, but precisely the physicists who see the need for dark energy clearly see it that way.
If you are not convinced that redshift is caused by Doppler effect, then you don't need any dark energy.
The discussion of the monks was about the smallest possible size, such a fixed plank species. I wouldn't mock them if I were you. There is no fundamental difference between the calculations about dark energy and the discussions of the monks. If you have read Stieglitz's article on monads you will understand what I mean.
Yoav
I don't think physics and math are as related to each other as you think. Mathematics provides tools for physics but as far as I understand they can certainly exist one without the other. The universe existed before man (at least 5 days), and without people there is no mathematics. And most of the topics that mathematicians deal with are not related to physics at all.
There is evidence for dark energy. There is no evidence of fairies. I don't think a rational person could think otherwise.
Miracles,
The discussions of the monks were not so far-fetched, especially if you consider that physics and mathematics are two sides of the same coin.
There is no scientific evidence of dark energy, but observations that created the need for power so that their model would not collapse.
If this is what I can complete, what bothers me is the force, academically and especially clerically, that backs up the model that needs dark energy. There are really a lot of dark energies in this story.
Strong
I'm glad to hear that the puzzle of the universe is small for you. You really sound like an educated and understanding person to me.
Just be aware that the lack of modesty is yours. You think that the one who is capable of creating an entire universe thinks you are more than an insignificant speck of dust. You think you are the pinnacle of divine creation. "Created man in his own image"? very funny 🙂
Yoav
There is at least one significant difference between dark energy and the ideas of the monks. The "evidence" of the clergy are the stories of her actions in the book, while the evidence of the physicists are observations of the world.
Dark energy has several lines of evidence, and there are several physical theories that explain dark matter.
Miracles
As for galaxies, there is a number one expert, his name is Yehuda Sabdarmish. He will explain this with the help of gravitational pushing particles.
Stop talking science fiction about 700,000,000,000 light years and 10 times 500 universes. Maybe to the power of 499?
The riddle of the universe is big on you and with a little modesty you have to admit that someone created everything.
Tens of thousands of people in the world invest tens of billions of dollars to develop something that tries to resemble human intelligence, while your elaborate brain (Ofer, Yoav, Nissim, etc.) was created by chance? By an evolutionary development of 10 to the power of 3000 years? And maybe to the power of 3001? To me it doesn't make as much sense!
Miracles,
How exactly is redundant? By the divine particle?
Or about creating a theory adapted to the biblical story of creation?
Dealing with "dark energy" seems to you a less mystical act than the discussions of monks in the Middle Ages about the number of angels who can dance on the tip of a needle?
Even then the discussion was mathematical.
Yoav
I didn't know that they studied about the Big Bang in the division. I don't think there is much doubt that there was a big bang, but there are many theories about what exactly happened then. If it says in these books that we know for sure what happened then, it's really irrelevant.
I think the big bang eliminates the need for a creator, which is the basis of almost every religious belief. Is evolution an explanation for the diversity of species in the world? What bothers the religious is that we and the apes had a common ancestor. Religion loses its power to control people if the person is not special.
I am very interested if evolution is taught in the division. At least regarding evolution there are no doubts.
Miracles,
Not children's books! Books for studying physics in elementary and high school!
I agree with you. Regarding religion, I see no need to add. What cancels evolution is the big bang theory. Or do you think that the creation of all elements in zero time is an evolutionary process?
Yoav
What do children's books have to do with science? Do you think they are written by scientists?
I can't explain many things. Such questions should be addressed to those who understand physics in depth.
What you said about the religious is not true in my opinion. They have a problem accepting anything that eliminates the need for a Creator and/or providence. Some do accept evolution, because they manage to introduce their God in another way (inventing a soul, talking about the next world and so on).
I don't understand how you rule out explaining to children who think there was a big bang, and on the other hand think that teaching a child about religion is something legitimate. Do you want to teach skepticism? Excellent - start with the fact that you teach that religion rules out curiosity.
Yehuda
You should start thinking about carbosilane. It is good against dihydrogen sulphide.
Miracles,
Look at children's physics books and you will see that this is presented as an explanation that has no arguments. And follow the bitter fate of the academics who doubted the explosion, to whom the light was light.
To attribute the enthusiasm of clergy to a lack of understanding, forgive me, but it sounds like misplaced condescension. What they like is de-evolution.
As for the best explanation for what we're seeing, I wonder how you manage to see superposition.
Shmulik
Thanks!!
Miracles,
He recently gave a lecture at the Perimeter Institute
https://www.youtube.com/watch?v=XJHbGvjWEzM
If I remember correctly, when I heard the lecture there were some questions that I thought did not receive a satisfactory answer. In any case, it's worth listening
Yosef
I tried to read about Verlind's theory. It's not easy for me at all 🙂
Vesto Melvin Slipher (/ˈslaɪfər/; November 11, 1875 – November 8, 1969) was an American astronomer who performed the first measurements of radial velocities for galaxies, providing the empirical basis for the expansion of the universe.
Didn't Edwin Hubble discover that the universe is expanding!
And Stu Sleeper discovered this after coming up with the idea of spectroscopically measuring the light coming from distant stars and interpreting the observed deviations! He made dozens of spectroscopic observations and lectured on them at conferences, at one of which Hubble heard the results and decided to join!
Verlind Eric's theories of entropic gravity is, in my opinion, the one that best explains the effects discussed in the article.
Since the universe is quantum even in a vacuum, a calibration activity (gauge) is carried out in it - this explains gravity and also the absence of dark matter in the universe, as there is no need for dark matter at all. The ingenious explanation, once made clear to us, is simple. But the kind of simplicity that we wouldn't have thought of on our own.
Yoav
I don't think anyone is arguing that the big bang is a fact. This is probably the theory that gives the best explanation for what we see.
The theory suits religious establishments only because they do not understand what the theory says.
Moti Shay
What you are saying now makes sense. Note that the distant galaxies are not necessarily accelerating. Because of gravity, we expect that the speed of receding will decrease over time at a certain rate. To say that there is dark energy, it is enough to see that the rate of deceleration is lower than expected.
Miracles,
My response refers to the approach that sees the Big Bang theory as a settled fact that cannot be challenged,
And as much as it is, a hypothesis that Gamov threw into the air with a wink.
It is true that it is very suitable for the religious establishments, which makes it very easy to obtain resources for research, but at the heavy price of avoiding doubting the theory itself.
Miracles
Yes, I was wrong, this is what I meant:
Galaxies about 10 billion light years away from us = high receding speed = it happened a long time ago in the distant past.
Galaxies are slightly distant about 4 billion light years from us = medium receding speed = this happened in the middle past.
Closer galaxies about 1 billion years from us = low receding speed = it happened not long ago.
Which indicates a slowdown...
Miracles
As time increases, the distance decreases
Because the distance relates to 3 dimensions (in the present), but in the fourth dimension the graph curves and faces towards
We stop looking forward and switch to looking back in time
Alon named before in the past 🙂
Miracles
Because the distance relates to 3 dimensions (in the present), but in the fourth dimension the graph curves and faces towards
We stop looking forward and switch to looking back in time
You can also try to assume that there was no big bang.
There can also be alternative solutions that do not require dark energy and still fit the data that is known today.
For example, that we are in a universe where there are waves/ripples, and we are before the peak of a wave (which explains the expansion we see today).
In this case the universe can be infinite or in any other finite form.
Yehuda
If your gas was expanding into empty space then its speed could not be greater than the speed of light. Therefore - it is not possible for a body to move away from us above the speed of light. But we know about bodies that move away from us faster than the speed of light.
And in any case, the bodies will not exceed the speed of the particles, right? And so with the particles at a constant speed then the bodies have a finite speed.
for miracles
I have already explained: for every body in a huge ball of gas spreading towards the emptiness around it, there will be a larger outward force vector than an inward force vector, and the difference will be an outward force vector, which means an outwardly accelerated movement of bodies.
Can't explain better
Shabbat Shalom
Yehuda
Yehuda
Why did you write "So why do you bring me an example of individual particles moving against the general flow"
Yehuda
On average they don't go anywhere, but that's not the point. You claimed that there was an acceleration - and I would appreciate it if you could explain what makes you think that way.
Miracles
When we talk about a gas that spreads, it is clear that the gas particles move in every direction and some even against the direction of expansion, but on average they move in the direction of expansion. So what do you bring me an example of individual particles moving against the general flow?
If there is gas and there is emptiness around it, the movement of the gas will be in the direction of abstraction and it is true that there will also be reluctant galaxies - Andromeda and the Milky Way for example, which will move against the general consensus (at least one of them)
In everything we are talking about the average movement of the gas particles.
I hope that makes sense because this is literally sophomore year stuff. Really Sears Zymanski.
Please respond gently
Yehuda
Moti Shay
What does your last comment have to do with the one before it? Pay attention - we don't see acceleration, we only see speed! We see that the ratio between speed and distance increases, so we talk about acceleration.
Read what you wrote again - I think you got confused.
Yehuda
A particle that doesn't collide with any other particle accelerates? You are probably explaining yourself unclearly if you meant something else.
Miracles
See the link: https://he.wikipedia.org/wiki/%D7%97%D7%95%D7%A7_%D7%94%D7%90%D7%91%D7%9C
Galaxies about 10 billion light years away from us = high acceleration = it happened a long time ago in the distant past
Galaxies are slightly distant about 4 billion light years from us = medium acceleration = this happened in the middle past
Closer galaxies about 1 billion years from us = low acceleration = it happened not long ago
The environment very close to us, this is what characterizes the entire universe now, here we have to measure the degree of expansion.
Miracles
I don't understand where you draw your conclusions from?. If the mean free path of the particles is of the order of even a few light years, the chance of meeting a particle after a million light years, which has not collided with another particle tends to zero, then maybe you are not trying to find an answer but only to insult and this is completely unacceptable to me and why should you even hear a response of a XNUMXth grade student
Bye miracles
Yehuda
oak
You wrote "as time increases the distance decreases". Why?
Yoav
Who are you referring to? Where has anyone here shown a lack of skepticism?
Moti Shay
You wrote "The farther away the galaxies are, the faster they move away from each other. That is, in the distant past the speed of the distance between the galaxies was higher than in the middle past."
Your second sentence contradicts the first sentence. The first sentence claims that the galaxies are speeding up, but the second claims that they are slowing down.
Yehuda
Let's go back to XNUMXth grade physics. A gas is a collection of particles, each particle having a certain momentum. When two particles collide there is an elastic collision between them, that is: both momentum and kinetic energy are conserved. A ball of gas in a vacuum is no different from a trapped gas, except that there are certain particles that do not collide. These particles will continue in a radial direction with the same speed they had.
Yehuda - quit studying general relativity. Get Sears-Zymanski's first book and learn basic mechanics. Your whole concept of "acceleration will act on the particles" is far from being physical.
We see the universe in 4 dimensions, distance is not really distance these time
The distance you see is a combination of time and distance (and as time increases, the distance decreases)
The acceleration of the distant galaxies must really be increasing, because we are looking in time towards the big bang
Zwicky did not accept the big bang theory, similar to Hubble himself, and claimed that the redshift originates from the loss of energy of the photons. He was treated disparagingly, and his assumption was called "the flight of light".
Later mainstream physics agreed that black holes cause redshift. So the photon can get tired.
Maybe the bang and light fatigue do not contradict each other but it is permissible to be a little skeptical. Skepticism is the spear of curiosity.
To Moti Shay
We, the Milky Way and Andromeda, are a special case in the universe and most other galaxies are moving away from each other. Now it has been discovered that not only are they moving away, they are even accelerating in their moving away. The scientists who discovered the distance received a Nobel Prize for the discovery and I strongly believe that their path to the solution was correct.
I do not agree with your words in your first comment that we can never know what is really happening there. I believe in the human mind that knew how to find ways to test different and strange ideas like yours and mine.
Good day Moti Shai
And welcome to our website
Yehuda
to Judah and miracles,
I agree with what you say in relation to what I said.
I can make things worse and claim that the universe today is collapsing in on itself and not accelerating and tell me if I'm wrong.
The farther the galaxies are, the faster they move away from each other. That is, in the distant past the speed of the distance between the galaxies was higher than in the middle past, and if a line is drawn then it is likely that today the speed of the distance is even lower and may have even turned into convergence.
Maybe that's why the Milky Way Galaxy is merging with the Andromeda Galaxy.
In my opinion, only if they find an accurate method for measuring the distance / approach in the environment close to us, will testify to the expansion / convergence of the universe today and not in the past.
for miracles
You touched on a correct and important point that will allow you to test the idea.
Explanation: A huge ball of gas spreading towards the emptiness around it will have a greater outward force vector than an inward force vector, hence the outwardly accelerated movement of bodies.
And indeed you were right. A smaller acceleration will act on the particles on the outside of the gas sphere and those in the outer layer will have a tiny, or zero, acceleration on them. The same goes for the particles in the center of the ball, a low or zero acceleration will also act on them.
And this allows us to present a way to test or refute the idea (according to Popper, every scientific idea must be shown a way to test it). And the idea that comes from your words is that there is a region in the universe where the acceleration is maximum beyond which the acceleration on both sides will be smaller. If there is no such area then the idea for my explanation of the spreading phenomenon is incorrect.
Please respond gently
Good Day
Yehuda
Yehuda
Why in a hurry? Look at the fastest particle in your universe. He is alone, all the others are behind him. What will make him speed up?
Is it easy to show? Please - why would the particle moving alone without any forces change its speed?
Miracles
How about the idea that our universe with all its many particles behaves like a gaseous body expanding into the void around it. It is easy to show that the expansion of the inner parts of the universe as above, will spread outwards with increasing speed, that is, with acceleration.
In this case you don't need dark energy to push. All that is needed is a gaseous universe expanding into the void around it.
What do you think?
Please respond gently
Good night
Yehuda
Yehuda
You're right. I meant that no one is saying that celestial body X is where we see it, or even where we assume it is.
Miracles
There is no reason to assume that the universe is not accelerating even today
Moti Shay
Nor is anyone claiming that what we see is what is happening now. The whole article refers to what we see happened in the distant past.
No one can really know what's going on out there in space, especially not in the distant universe.
Because of the speed of light we are actually cut off from the universe and it is possible that the universe has started to converge on itself and we don't know maybe we will know later.
Look at the sky, it's not real, many stars are actually not there and others have moved and changes have happened to the stars themselves.
We look to the sky and look to the past!!! What is really going on there no one knows and will not be able to know.
Peace to all the inhabitants of the universe in which the earth is located.
I am writing this message to you from another location, know that string theory is quite accurate.
Hello, I hope the message arrives.