Physicists have caught a glimpse of a particle that is a candidate for the mysterious dark matter. The scientists: "conclusive conclusions remain in question"
In December we reported on uncertainty regarding the results An experiment to discover dark matter was conducted in an abandoned mine in Minnesota. The article that reviewed the research was recently published in Science, and its editors hope that additional experiments that will last five years will give more definite results.
A search that lasted about 9 years in a special observatory in an old iron mine deep underground, may have located two weakly reactive particles (WIMPS). But researchers, including two physicists from the University of Florida, say there is a 1 in 4 chance that the detection was just background noise - meaning that the frantic search being carried out by thousands of scientists in at least a dozen observatories will continue.
"One or two cases, it's difficult. The numbers are too small," says Terek Saab, a professor in the Cryogenic Research for the Search for Dark Matter (CDMS II) - an experiment conducted at a Sudan mine in northern Minnesota.
An article presenting the results is published in the February 11 issue of Science.
Scientists have known for a long time that the rotational speed of galaxies and the behavior of galaxy clusters cannot be explained by "traditional" gravity alone, based on the calculations of the masses seen in galaxies and clusters.
Other matter - which is invisible, and undetectable, and yet, unusually strong - probably produces the force necessary for the higher than expected rotational speed in galaxies and galaxy clusters, as well as other anomalies that can be discerned in observations.
According to estimates, what we know today as "dark matter" (dark because it does not reflect or absorb light in any way) constitutes about 23% of the matter in the universe. But despite its definite effect on matter, no one has ever directly observed dark matter particles.
There are several options for the composition of the mysterious substance. The particle theories of physics point to WIMPs as one of the possible candidates.
The WIMP particles are "weak reactants" because, although their masses are equivalent to the masses of standard nuclear matter, they have very little interaction with normal matter.
Among other things, this is what makes them so elusive and difficult to find.
However, scientists believe that WIMPs occasionally "kick" or jump on an atomic nucleus, leaving behind a small amount of energy that can actually be detected.
The observatory of CDMS II is located almost a kilometer below the rocky ground that blocks most of the particles, such as those that accompany the cosmic rays. At the heart of the observatory, germanium and silicon sensors are frozen to minus 237.54 degrees Celsius, just above absolute zero. According to the theory, WIMPs will be among the only particles that will manage to pass all the way through the earth and rocks, and then they will "kick" the atoms in the sensors, thus creating a small difference in heat, a signal that will be observed and recorded in the experiment's computers.
Dordana Balakshieva, a postdoctoral student in physics, and Seb participated in the analysis of the data generated by the experiment, as well as in the simulations of the sensors' responses. They helped test many sensors for the experiment.
The 15 institutes participating in CDMS II collected data from 2003 to 2009. The researchers recorded two WIMP events in 2007, one on August 8 and the other on October 27. Scientists estimated that five sensors would be enough to confirm the WIMP particles - which means that more such events need to be detected. But while more research is needed on the subject, the two findings nevertheless give strength to the theory.
"Until now, not only us, but everyone operated without statistical data - we were like blind in that sense," says Balakshieva, "but now we can start talking in statistical terms."
"Many believe that we are very close," says Saab. "We expect or certainly hope that in the next five years or more, someone will notice a clear signal."
90 תגובות
By the way, Eddie:
It turns out that I'm not the only one who came to this conclusion.
Feel free to read on The slingshot cluster on Wikipedia.
In the first paragraph it says:
it was found that the spatial offset of the center of the total mass from the center of the baryonic mass peaks cannot be explained with an alteration of the gravitational force law
Eddie:
I didn't ask for good theories from MOND, but theories that explain the findings.
There are none except that of the dark matter.
Michael,
L - 63:
You will find examples of successful theories (more than MOND, in general) in my responses to the article I mentioned in 60.
ghost moon
Observations differ from an experiment: an experiment is a controlled thing carried out in a laboratory where the experimenter controls the parameters of the experiment. An observation is not an experiment in which the experimenter simply measures without the ability to control the parameters of the phenomenon. In astronomy, observations are made, not experiments (except in isolated cases).
We'll wait and see (I also hope that we will live long enough).
ghost moon
Observations differ from an experiment: an experiment is a controlled thing carried out in a laboratory where the experimenter controls the parameters of the experiment. An observation is not an experiment in which the experimenter simply measures without the ability to control the parameters of the phenomenon. In astronomy, observations are made, not experiments (except in isolated cases).
To Michael
We'll wait and see (I also hope that we will live long enough).
sympathetic:
It seems to me that we are treading water.
I don't agree with your words in the previous comment, but we have already deviated so much from the topic that it is simply a waste of time.
I tried to get an answer from you on a simple question but you didn't cooperate.
At least try to give yourself the answer and remember on that occasion that we both understand - it was you who defined yourself as an instrumentalist.
Beyond the simple question - I also pointed out to you a possible situation in which reality will be such that you simply will not agree to accept it (dark matter that performs gravitational interaction only).
This seems to me to be a very strange approach, but if you are not convinced, we probably have no choice but to wait and maybe see.
sympathetic
What do you mean by the word "observations" in response 83?
You mean what the eye sees?
Or do you mean measurements obtained in laboratories?
I'm sure you know that there are things that the human eye cannot see, like X-rays for example.
Because you don't see the dark matter, but you get "noises" in measuring devices that have an effect
For the formulation of the result, we must rely on "something that exists there" but we don't see it.
"Exists" because if it did not exist the results of the formulations would be as they were calculated, regarding a certain thing.
Because the results show a different answer than what was thought about a certain thing, and there are "noises"
That cannot be explained with measuring devices, it is assumed that there is something and they called it "... dark".
Apparently this dark something is not in the same range of human vision, but it does exist in the location
Another on the scale (perhaps from the X-ray or microwave side).
Or at all we need to invent a new scale for higher energies or at least add one more radiation.
Fermat's hypothesis was built on exactly such a series of confirmations. Many times in mathematics, a rule is assumed from a number of private examples (as Babel apparently did Fermat) and the rule/hypothesis is proven later.
Again I will repeat that there is no evidence for the existence of dark matter there are observations that are not understood. Evidence of the existence of a thing is the ability to use it to predict something that we have not yet observed. Quantitative predictions cannot be made using dark matter, so scientifically there is no evidence of its existence. We concluded that the observational superiority of dark matter over competing theories is based on a single experiment and science is not built on the basis of a single experiment (this should not be compared to a counter example in mathematics).
The last points are important - because in physics there is a finite number of everything, you can find many theories that will fit a finite number of points, how will we decide between them, we will extrapolate the results to something that has not yet been measured and by experiment we will find out between the theories. In physics, unlike mathematics, a single example is not enough to build a theory, the number of independent measurements is necessary. One of the reasons for this is that the probability of an accurate experiment is less than 1, that is, there is a probability of error. The more the experiments, the smaller the probability of error. As the amount of experiments that are performed increases (I measured this amount in time in the examples I gave) and nothing is found in the experiment, the likelihood that it exists disappears. I really liked your circular argument. There is a factor that cannot be discovered and it is responsible for something. The more we look for it, the more we prove its existence. I will give you another example like the one you gave me: each of us has a soul that determines how we behave, but it is not measurable. The more scientists look for the soul and do not find it, the more likely it is that it exists.
Unlike physics where there is a finite number of everything, in mathematics there is an infinite number of numbers and any series of "confirmations" you get is still a zero percent of the total.
The Achilles and the Tortoise "paradox" is an example of an incorrect conclusion that can be drawn even from infinite "confirmations".
Suppose that the dark matter really only interacts gravitationally with the baryonic matter.
Maybe?
Definitely!
One of the consequences of this fact will be that we will never find it in the laboratory.
In fact - not finding him would be a confirmation of this feature (just as not finding him at the moment confirms the assumption that he hardly ever performs such an interaction).
Meanwhile there is strong evidence for its existence and no evidence against its existence.
Also there is no theory that makes him redundant.
I don't think anyone would conclude that he doesn't exist just because of the time.
If there is someone like that, I will think that he does not use logic.
By the way - there are maps of the estimated distribution of the dark matter.
Let's say we had technology that allows movement over great distances in reasonable times.
Suppose you had to go on an interstellar journey where your vehicle is subject, in its rest, to the gravitational effects of dark matter.
Would you equip yourself with a map?
We don't have such technology - so let's wait "a little" until we have it.
Maybe in a million years.
Let's say that during those million years they didn't find dark matter, but they also didn't find a refutation of its existence and didn't find a theory that makes it redundant.
Note: a million years have passed!
Would you equip yourself with a map?
And what about 100 million years?
Let's leave the banal difference between the mathematics (from where your examples come from) and the physics - research in physics costs hundreds of millions of dollars and not just people's time so the researchers tend to be more practical. The examples you gave only strengthen my claims as the years went by when people actively searched for an integer greater than two that satisfies the formula so they realized that Fermat's hypothesis is probably true. This feeling became stronger with the invention of the computer, which made it possible to calculate larger and larger powers, but again there was no certainty. As time passed and no counter example was found, people became convinced of the correctness of the hypothesis.
On the other hand, as time passes and the dark matter is not found, a reasonable person will assume that this is a false hypothesis.
You know how long it was believed that there is no n greater than two and natural a, b and c so that
a^n+b^n=c^n
?
They believed, believed, believed, continued to believe, and finally - after hundreds of years - they proved it.
To this day it is believed (after hundreds of years) that every even number is the sum of two primes.
It has not been proven yet.
Neither of these two beliefs has had as strong a confirmation as the dark matter hypothesis.
I'm interested in whether you think there was someone who came and said that Newton's theory should be replaced just because a long time has passed without anyone disproving it and without anyone proposing an alternative theory.
There are facts that are revealed and there are facts that as time goes on are not revealed and the reasonable person will understand that the latter are not facts. A negative result for the experiment is also a result. See the example of the Higgs - which I'm sure will be discovered, but if the scientists don't understand that it will be necessary to change the theory.
There is a difference between a belief that is based on nothing and a belief that stems from logical considerations.
They did not believe that Newton's theory would be found wrong because they did not know that there were facts that disproved it.
As soon as such facts are discovered, look for solutions and eventually find them.
What has changed is not the time that has passed but the facts that have been discovered.
This is exactly what I also said in my previous response and there is not even a hint of a reason to change my mind in your words.
In the past, it was believed that Newton's laws would never be disproved. Nor did they believe that there could be atoms. Human thought and imagination are limited in the face of nature and we learn this important lesson over and over again. Therefore, to you and to a (large) part of the scientific community, it does not seem today that an alternative theory of gravity is possible, but it does not mean that there is not one.
To understand that you are wrong (if this is indeed the case) there is no need for me or anything else to prove it, it is necessary to understand that if you follow a certain direction for a long time and have not reached results, the more time that has passed, the more likely the direction is wrong. Only the religious dogma does not change while science is fundamentally pragmatic if a certain direction does not lead to results it is abandoned no matter how promising it seems at the beginning. By the way, I don't assume that for 13.5 billion years scientists tried to find rocks and only then found them. I don't suppose that scientists have been looking for electrons for hundreds of years but when looking for evidence that supports a certain theory and it is not found a pragmatic person will change his views. By the way, I would be happy to hear how, in your opinion, the dark matter theory can be disproved in this theory with enough parameters to describe almost any observation and since I do not see it as a scientific theory, only in retrospect it explains observations and does not predict them. For me, the theory of dark matter is equivalent to a theory that says that the laws of physics are dependent on place and in every galaxy there are other laws of physics that deflect the light so that it fits the observations on the surface of the earth.
By the way, I'm not sure that the "site" theory has ever been disproved, just stop looking for it. Maybe we should continue to look for the "site" and break up the private relationship? In it we will take the Higgs for example if it is not found in the LHC experiment
Will they continue to look for it because of the amazing success of the elementary particle model or will they change the model. Blind faith in a model is not scientific faith.
sympathetic:
I don't think it is possible to define a gravitation theory that is both consistent with what we know and also gives a gravitational pull around nothing.
If you think it is possible - you are welcome to demonstrate it.
The time that will pass will have no effect on my position.
What can affect them is the discovery of dark matter, the refutation of the possibility of dark matter or the discovery of a theory of gravity that makes it redundant.
It took 13.5 billion years until they discovered that there were rocks.
Since then, tens of thousands of years have passed until they discovered that there are electrons.
Time is not a factor in the story.
Environmental pollution around nothing does not confirm the dark matter, it is possible to think of different gravitation laws that would give the same phenomenon. The point is that the dark matter theory claims that there is dark matter and until it is found it is speculation and not a confirmed theory.
For the sake of curiosity, let's assume that dark matter will not be found in the next 10 years, will you still believe in the theory? And if they don't find it in the next 100 years, will you still believe in the theory? And if not in the next thousand years, will you continue to believe in the dark matter even then (assuming you knew how to extend your life for such a period - this is also valid for 100 years)? So you are telling me that you believe in something that cannot be established, but he makes sure that the mistakes we see are sorted out. I am afraid this is equivalent to believing in God or in an angel who arranges the eyes....
to appreciate = to extend. A Freudian slip
Michael
Environmental pollution around nothing does not confirm the dark matter, it is possible to think of different gravitation laws that would give the same phenomenon. The point is that the dark matter theory claims that there is dark matter and until it is found it is speculation and not a confirmed theory.
For the sake of curiosity, let's assume that dark matter will not be found in the next 10 years, will you still believe in the theory? And if they don't find it in the next 100 years, will you still believe in the theory? And if not in the next thousand years, will you continue to believe in dark matter even then (assuming they knew how to value your life for such a period - this is also valid for 100 years)? So you are telling me that you believe in something that cannot be established, but he makes sure that the mistakes we see will be sorted out. I am afraid this is equivalent to believing in God or in an angel who arranges the eyes....
sympathetic:
M94 is an extreme example of a general case and it is a fact that in different galaxies different percentages of dark matter are assumed.
The slingshot cluster is also an example and again - this is a prominent and characteristic example of a general phenomenon that manifests itself in different ways in other places as well (like littering around nothing).
The spherical configuration of the gravitational clumping at the center of galaxies versus the elliptical configuration of the mass distribution is another and independent piece of evidence.
And finally: the new king's clothes is a children's fairy tale. In reality - in most cases when the child says something that sounds like nonsense, he is indeed saying something nonsense.
https://www.hayadan.org.il/a-prototype-detector-for-dark-matter-in-the-milky-way-2909094/#comment-251262
Michael
I did not state that the scientists who conducted the experiment were wrong, I stated that in my opinion their claims would be false. First, the noise assessment is a complex operation, I'm not sure how you derive a 75% certainty number from it, but again I haven't checked the calculations so I can't claim that the number is far-fetched. Second, science, like any human activity, is tainted by politics. Scientists need to finance and justify their experiments, and a study that has been in operation for 9 years should explain why it should be continued. Many times a false discovery is not made on purpose, but rather the scientists want to discover something so much that they round corners in the statistical analysis. Again, all this is pure speculation and it's very possible that I'm wrong, so we'll wait patiently because the scientists don't claim to have discovered dark matter with a probability of 1...
Regarding your reasons, they are good and beautiful, but they are based on a single experiment of galaxy M94, and as mentioned, even after seventy years of searches, the dark matter has not yet been found, so your reasons are beautiful, but they have not yet been empirically proven, therefore they have no scientific validity. What's more, I gave a number of examples of reasons behind which there was a mathematical theory that were falsified in the experiment. This is not to contradict your reasoning, but to show that when we come to explain any phenomenon, we must be modest. This is a lesson learned over the years of scientific research. The beauty in nature which is often more complex than the human imagination.
Regarding nagging, I remind you of the story "The King is Naked" about scientists who claimed that only smart people with degrees were able to understand their theories and only a small, uneducated boy understood that the theories lacked foundation. It is not enough for experts in the field to make a certain claim, they must stand behind it, what with the fact that in this case there are experts who think otherwise, for example Prof. Milgrom. Nowadays there are not enough experiments to determine which is the correct theory. Science is not based on a single experiment and another experiment whose results are correct with a probability of 75%.
abandoned. You will no longer be religious.
If you can 'be religious for a moment' (but only for a moment) then you can say that a 'soul' exists, but it does exist
Only in the brain, maybe this gray matter even has a connection with the dark matter if we think in this direction
So it is possible to resolve the soul from the whole body except the head, that is, it (remains) in the brain and the spine and so on
It does not interact (almost) with gravity and does not have to have the properties of normal matter.
And also takes the form of a tadpole or spiral with 'one arm'.
This. sorry father
Are laboratory conditions the only place where you can look for dark matter (or truth)?
After all, laboratory conditions are preceded by the thinking that the brain produces. (The brain also has gray matter which is a type of apple 🙂 )
sympathetic:
But when emphasizing, it is advisable to emphasize correct things.
When the experimenters report that the probability that they discovered a dark matter particle is 75% then reporting the truth is not that they didn't find it but only that you allow yourself to say (without talking to them or reading exactly what they did) that they are wrong.
The scientist must know how to estimate the level of background noise.
They are scientists.
They appreciated the background noise.
Do you know how to do it better than them?
Did you do that?
The truth is that you didn't answer my argument either (except that you said there were already people who were wrong - as a hint that maybe I'm wrong too, although the exact same hint can also be interpreted as a hint that you're wrong - what's more, my words are reasoned and yours are not).
In my opinion, the evidence for the existence of dark mass is extremely convincing.
And by the way:
Constantly looking for an alternative theory.
In fact since the idea of dark matter was brought up.
There is no need for steams to cause this because neither yours nor anyone else's steams will drive any scientist and the motivation to search for an alternative theory is self-evident.
Of all the alternatives that have been put forward so far - only the dark matter theory has not been disproved.
Michael
Indeed there is no point in repeating the debate. It is only important to emphasize in the responses on which findings each theory is based so that they can try to assess the credibility of that theory.
Regarding your question why I don't believe that dark matter is in the experiment described in the article, well
Do the scientists quoted in the article tell us what the dark matter particle is, what its mass is, for example, what are the quantum numbers that characterize that spin, is it fermionic or bosonic, then no. This is about a level of noise in the detectors that seems to be abnormal, but noise is a very deceiving thing. A scientist must know how to accurately assess what the background noise is in order to determine that any noise is truly abnormal. The lost material…
Hello Eddie,
In this sense, I am only (as it is called on the website) a locomotive. For me, the situation today is a situation that precedes a scientific revolution in the language of Thomas Kuhn Carey, they try to fix the old theory so that it can explain a new set of experiments that cannot be explained simply by the theory. For example, I will once again mention the invention of the "website" designed to explain the Michelson-Morley experiments. Here the idea is to introduce a new type of material. Why do I grumble because the question is how long will the idea of a new material take hold? Is it after a decade that scientists must realize that it has failed and should we look for an alternative theory? Is it after fifty years or is it after a century? There is a finite time in which to understand that a mistake was made and to search in a different direction. As far as I'm concerned, steam exposes the scientists involved in the field to criticism that they must defend against as best they can or choose a different option.
Michael
Indeed there is no point in repeating the debate. It is only important to emphasize in the comments which findings each theory is based on so that readers can try to assess the credibility of that theory.
Regarding your question why I don't believe that dark matter is in the experiment described in the article, well
Do the scientists quoted in the article tell us: what is the dark matter particle? For example, what are the quantum numbers that characterize it? What is his spin? Is it fermionic or bosonic? So it's not. This is about a level of noise in the detectors that seems to be abnormal, but noise is a very deceiving thing. A scientist must know how to accurately assess what the background noise is in order to determine that any noise is truly abnormal. The lost material…
Hello Eddie,
In this sense I am only (as Michael calls it) a locomotive. For me, the situation today is a situation that precedes a scientific revolution in the language of Thomas Kuhn, that is, they are trying to fix the old theory so that it can explain a new set of experiments that cannot be explained simply by the same theory. For example, I will once again mention the invention of the "website" designed to explain the Michelson-Morley experiments. Here the idea is to introduce a new type of material. Why do I grumble because the question is until when the idea of a new material will catch on, is it after a decade that scientists must realize that it has failed and should we look for an alternative theory, is it fifty years later or a century later, there is a finite time in which to understand that a mistake has been made and search in a different direction. As far as I'm concerned, steam exposes the scientists involved in the field to criticism that they must defend against as best they can or choose a different option.
Eddie:
If you claim that my argument (which is well reasoned, regardless of MOND) saying that no theory of gravity will solve the problem is "simply not true" - you must have a counter example.
Otherwise - how do you know it's not true?!
please; Show us the same counterexample (or, alternatively, the basis of your argument).
My hypothesis is that dark energy is like the "precursor" of gravity (perhaps a sort of anti-gravity)
There is the strong force followed by the weak followed by electromagnetic and followed by gravity (that's how I understand it)
So in my opinion dark energy is a force that is weaker than gravity but still sustaining
Interaction with gravity and from this interaction dark matter is created.
With the help of an example I will try to explain: after when say a grenade explodes then what the eye can see
It's a ball of fire and gas clouds that relatively quickly disperse in space.
What the eye does not see (but exists) is the surface waves and a magnetic field that is created on the spot (perhaps temporarily).
I see in the dark matter something that resembles that page wave that was created after some kind of explosion (perhaps a star)
That is, a type of "cloud" that produces a field of some force of its own (perhaps one that produces gravity).
As far as I know there is a hypothesis that black black can not only destroy galaxies but
Black holes also "give birth" to new galaxies, I don't remember exactly the exact explanation
I'm bored of these hypotheses but the explanation is also related to matter and dark energy, and what I am
It is thought that the field created after the particles are ejected from a black hole is a field of the energy force
The darkness, after the creation of the field, in the interactions with the baryonic particles, the dark matter is created
And the dark matter in some interaction produces a new field (gravity) and the formation of normal matter begins.
To anonymous from response 13
Why don't you move to one of these countries (as a sign of identification), maybe there you can use the advanced technological knowledge that exists there, unlike in the primitive USA that has contributed nothing to human knowledge...
Ehud Shalom,
If you remember, we already discussed the subject of the theory about the dark matter, around the article "A prototype of a dark matter detector for the Milky Way".
I agree with your approach on the issue.
I just want to add and comment that the claim that sounds like there is no good theory (of gravitation or even a certain quantum theory) that explains the observational findings, and makes the dark matter hypothesis redundant - is simply not true.
It is convenient for the supporters of the dark matter hypothesis to present the MOND theory as if it were the only theory to consider for the purpose of negating the consumption of the dark matter hypothesis. Such a position is not correct - there are some better and more durable theories. I myself took the trouble and presented them in the various comments surrounding the article I mentioned ("prototype...").
And by the way - you say (emphatically?!) that they did not find dark matter in the laboratory, even though the authors of the experiment in question claim that there is a 75% probability that they did indeed find dark matter in the laboratory.
And by the way:
Professor Milgrom did not participate in the M94 testing and said his words only to defend his theory.
He didn't say he thought they were wrong but said they might be wrong.
Beckenstein, who felt less need to defend MOND, agreed that even if MOND and its derivatives are adopted, dark matter is needed.
sympathetic:
I have already expressed my opinion and I will not repeat my words just because you repeat your words.
questionnaire:
Physics can certainly exist and progress (and even accelerate its progress) if people don't waste time on trolls, steams and stupidity.
Just as physics cannot exist without observations, experiments,
Calculations, confirmations and predictions it also cannot exist without
The human qualities, i.e. annoyance, trolls, brilliance, skepticism, humor,
Stupidity, innocence, intuition and several thousand other qualities.
There are no robot scientists (I hope) and the "known" knowledge belongs to no one.
What would improve the discussions here are a little modesty, innocence, mutual respect
And the understanding that everyone comes from a different level of education and understanding.
First, challenge the validity of a scientific theory even if the challenger does not have an alternative theory, this is not steam, this is the essence of science. This is not a hi-tech company, and those who criticize should come up with a better offer. The authority of a theory comes from its confirmation by repeated tests and not from the authority of the scientists who support it. Criticizing a theory is necessary for the advancement of science and one must answer factually about the claims. Criticizing reveals the weak sides of the theory to those who seek to form an opinion.
Relevant to the topic of dark matter.
facts:
1. Dark matter, despite being predicted for over seventy years, has not yet been discovered in a laboratory.
2. Dark matter originated in astrophysics and not in the theory of elementary particles.
Given these facts, the subject should be approached with modesty. If Prof. Milgorm says that the experiment of M94 is possible
He is not accurate, he may be right, because this is a field he understands. In astrophysics, the accuracy of observations is lacking, for example the attempt to determine the Abel constant for which the two results did not agree with each other and contradicted each other. Finally, the determined measured value is between the two values measured by the leading groups in the field (and outside their error limits if I am not mistaken). In other words, it is possible that some of the experiments have errors. It is reasonable to claim this about any theory, but it becomes more difficult and more difficult if there are dozens of independent experiments that confirm the theory.
Second, the M94 experiment and heavy research do not prove the existence of dark matter as you are trying to claim. This may be due to existing knowledge, but there are always surprises in science and that is what makes it fascinating. Just speculations that don't need to be addressed, but what if for example the universe has another dimension and then we have to take it into account. It is possible that the imposition of four dimensions or three dimensions of space causes different things to look the same. This is just speculation, but the subject should be approached with modesty. Below is a list from my memory of things that scientists said were impossible and they were measured in a laboratory or carried out:
1. It is not possible to superconduct at a temperature higher than 30 degrees Kelvin - they were found on conductors at much higher temperatures (the mechanism of superconductivity is different and to this day it is not clear what it is).
2. It is not possible to cool atoms above a conducting wire carrying a current at room temperature - it was done in a laboratory and today there are dozens of laboratories that perform this.
3. A train with passengers will not be able to travel over 50 km/h (I don't remember the exact estimate) without the air being sucked in and the passengers dying.
From the field of mathematics:
All the axioms of the geometry of space are necessary, i.e. there can be no geometry without the aforementioned axioms - non-Euclidean geometries were developed.
Even the site at the time seemed to be a necessary choice to explain why cylindrical transformations do not work and was found to be a wrong assumption. Therefore, what appears to be a logical conclusion is not necessarily so. Especially with the whole theory standing on one single measurement of galaxy M94!
In conclusion:
Dark matter has not yet been found.
The supremacy of dark matter over alternative theories, of changing the theory of gravitation, is based on a single experiment that some question its merits. Any reasonable person will decide based on this information.
Everyone is invited to present their opinion
Michael
thank you for the answer.
The dark matter theory seems logical to me for the same reasons you mentioned. I also believe that dark matter exists.
So as I understood from your words, the MOND theory will at some point join the ether theory and such, yes?
sympathetic:
I just expressed my opinion.
I know my father and talk to him a lot and I assume he agrees with me. If not - he also knows how to write.
Just because you don't know Judah's theory doesn't mean others don't.
Hint: When Yehuda says that they asked him not to talk about these things every time, it is because he talked about them every time.
The site is a news site and it would be strange and wrong if it didn't bring the news.
When there is a new scientific theory and the scientific community discusses it - there is no reason not to present it on the website.
Anyway - what is "new"?
My opinion differs from yours on this matter radically.
In my opinion, steams have no place in the scientific discussion. Science is meant to promote knowledge and the steams do not promote any knowledge. They merely describe the locomotive's mood.
The progress of science consists of a loop of experiments and formulation of theories.
In no document describing the progress of science will you find that steams are included as part of this loop.
Some theories have received less confirmation than others.
that's a fact.
What do you achieve by saying it again and again?
I think nothing.
I accept your opinion that a scientific website should not engage in gagging and I also add that it should not engage in theft, tax evasion and murder.
I'm just wondering how this belongs in the discussion.
When I present my opinion I present my opinion. not your opinion
When a conclusion seems compelling to me, I say it is compelling.
You can add the word "in my opinion" before each sentence. This is, in my opinion, the classic case of "everything that adds up diminishes".
Once, when I was sitting in a discussion with Amnon Lipkin Shahak during his time as Chief of Staff, someone started to express his opinion on a certain matter and said: "I say that..."
Amnon Lipkin Shachak jokingly interrupted him right after the letter "S" and told him "always what you say is what you say".
Anyone ever tried smoking dark stuff?
I tried to send my opinion about how a discussion should be conducted on a scientific website, but for some reason it was blocked?
In my opinion, the public should be allowed to judge and there is no place to rely on the opinion of the majority and perform gagging. I hope that my reasoned response will be released, I'm sorry that the automatic filtering system is wrong from time to time as I didn't mean to hurt anything.
It turns out that the above discussion goes far beyond the discussion of dark energy.
If all the respect I have for you Michael and I have great respect, there is a question that is required from your previous answers.
Although you have a long history on the site and managing comments, do you also have an official position on the site as this is not indicated on the main page. If you do not have an official position, why do you decisively determine what is allowed to appear and what is not, in particular your answer to Yehuda (response) number 38:
"His way of knowing what is scientific and what is not is to rely on sources where it is known that the scientific standard is maintained.
It is not intended to support speculation about scientific theories nor to "promote" theories that do not meet scientific standards in that they are not substantiated or have not been subjected to peer review."
I am not familiar with Yehuda's theory and it has also received strong criticism here, but nevertheless I would like to open the discussion on the question of what should have appeared in the comments on a scientific website. I agree that the responses are not intended to "promote" theories that do not meet the standards, and I will also add and say that in my opinion there is no room for discussion of new theories since these must be judged by the scientific community, but (and this is a matter of great sadness) science is not a sect or a religion and unlike the above it is based For what you contemptuously call steams. Site readers
may and should understand to the best of their ability what the basis for a certain theory is, what tests it has passed, how it fits into the whole of science. Scientific theories are not uniform, there are those that have been confirmed multiple times in a large number of experiments, there are those that are currently being tested in accelerators that cost billions of dollars and a single particle is needed to complete the puzzle, and there are also those (dark matter) that, despite a very large number of expensive experiments, have yet to be confirmed. Michael Mada is not a hi-tech company and does not need to come up with an alternative solution if something looks bad. It is permissible and necessary to grumble and the analogy of the naked king has taken center stage in scientific history several times. Scientists make mistakes Most scientists make mistakes and the public is entitled to be impressed by how much their claims are backed up and therefore what is the likelihood that they will succeed. An unwanted scientific site that will engage in gagging.
In my opinion, every person from the Yishuv deserves to be able to ask intelligent and non-nasty clarifying questions and have the stage for this and also the ability to receive a spectrum of responses not only the orthodox response. This is not about the rabbis and every person from the settlement will base his opinion on the subject based on the information presented to him. In addition, anyone dealing with a scientific subject should deal with it with modesty and not firmly state "therefore the difference must be something other than the laws - something that is there and causes the differences, this something is called dark matter." The difference doesn't have to be apparently ever according to your opinion or even logically it seems to be... There have been several examples in science and at least one received a Nobel Prize when a researcher succeeded in doing something they thought was impossible. There was proof that there cannot be superconductivity at temperatures higher than 30 degrees Kelvin. In 1986, a superconducting material was found at a temperature above the barrier, and since then many more materials with a high critical temperature have been found.
I wrote enough about my opinion on how a website should be run. Although we have had the discussion more than once, I will later repeat some of my opinions regarding dark matter because I see that there is renewed interest in this
Ghost:
Let's start with the fact that Professor Milgrom also knows that MOND is incorrect because it does not agree with the verified predictions of relativity.
The one who helped Milgrom create a new theory that was supposed to replace MOND because of this problem was Jacob Beckenstein.
I talked (and corresponded) with both of them and their reactions are as follows:
Milgrom does not rule out the existence of dark matter but is not sure that it exists.
To remain "uncertain" he chooses, for example, to believe that the measurements made on M94 may not be correct.
In other words, because the theory is his, he prefers not to confront head-on facts that were discovered after he formulated it and that completely contradict it.
Professor Beckenstein is sure there is dark matter. He's just not sure if this dark matter isn't bully. When I asked him how he explained my findings the slingshot cluster He just didn't answer.
The matter is all in all quite simple and in my opinion you can understand it and you don't have to look for experts on the matter, but if you feel that you don't understand and that you have to rely on experts - doesn't it make sense that you choose to believe the vast majority of them and not a small minority of them?
Why do I say that you can understand on your own?
Because M94 is an entire galaxy that behaves exactly according to the theory of relativity without needing dark matter.
If the laws of gravitation were different (as proposed by MOND and its successor developed by Bekenstein - TeVeS) this galaxy would also have to rotate faster.
As I mentioned - the existence of galaxies that look the same and rotate at different speeds (and M94 is just an example of this general problem) cannot be explained even in principle by any change in gravitation (be it MOND, Schmond or any other change). It really surprises me that people have trouble understanding this.
In my opinion, this fact alone is enough to convince of the existence of dark matter because, as mentioned, it is not possible for the problem to be solved by changing the gravitation formulas.
But this fact is not alone and although it is sufficient there are other facts that require the existence of dark matter.
One of them is the phenomenon of gravitational clouding around areas where there is no visible mass.
The existence of such regions also proves the existence of the dark mass beyond any reasonable doubt.
There remains only the question of whether the dark matter is bully or not and this question finds its well-reasoned solution mainly through evidence such as the Slingshot cluster where we see star clusters whose visible part is still in the process of a massive collision but the gravitational collapse shows that their centers of gravity have already passed through each other a long time ago.
Added to this is the fact that the amount of dark matter in some galaxies is really huge (a thousand times more than the visible matter) and it is impossible for so much baryonic matter not to produce stars (and it is certainly not possible when galaxies collide.
If all this is not enough, the fact that the measurements of gravitational dusting shows that the dark matter of the galaxy - unlike the baryonic matter - has not flattened into a disk shape and its distribution is spherical.
If the dark matter had a non-gravitational interaction with the normal matter or with itself - it too would have to flatten into a disk shape (I will not go into the explanation of this claim here, but those who understand physics in depth will understand it).
In conclusion:
The choice seems really easy to me.
Michael
Personally, I support the dark matter theory, at least as I understand it broadly
Seems reasonable to me.
But I don't ignore facts. for example:
Wikipedia says (about MOND):
The prevailing explanation for the missing mass problem assumes the existence of dark matter, the essence of which is still unknown. Milgrom's solution obviates the need to assume the existence of dark matter, because it corrects Newton's laws of mechanics so that there is no mass missing for the abnormal dynamics that others define as a problem.
I ask myself (as one who has no knowledge of the issues) who to believe?
to wikipedia?
To Professor Milgrom?
to you?
Maybe you are wrong and Professor Milgrom is right with his theory?
How come you are right about MOND?
Year:
As an expert in logic I tell you that there is no logical problem here.
Basing on the findings - as in any theory - is only "until proven otherwise".
This is the nature of science.
As I said (and you ignore) what emerges from the findings is not that the theory of gravity does not explain everything that is seen but that no theory of gravity will do so.
As I already said - there is no minority opinion here (meaning - not a scientific opinion): Did Ehud do any of the three actions I mentioned in my previous response? no and no!
Can you tell me exactly what his opinion (in your opinion) is?
He does not say that he can show that there is no dark matter.
He also does not say that he has an explanation that excludes dark matter.
All he says is that the confirmations are not enough for his taste.
Well - it's up to you and everyone interested in science to know:
The confirmations are never enough and we are always looking for more experiments that will further confirm or disprove the existing theories.
This is true for dark matter and it is true for any other theory as well.
To Ehud's credit, he is indeed working on an alternative explanation.
I don't think he will find it, but if he does, I will be the first to congratulate him on it.
As long as he did not present another explanation he did not say, in fact nothing.
Michael, as the debate has been conducted here, there is certainly a logical problem.
The working assumption that there is dark matter is correct, but its substantiation by the findings it comes to explain is incorrect.
The fact that the theory of gravitation does not agree with the new data does not prove the existence of dark matter.
And of course I don't have an opinion, but the opinion of the minority (Ehud) should not be rejected using the "majority opinion".
Year:
This is not about something for which a physical theory is lacking, but a situation where the findings prove that it is not possible for any gravitation theory to fit the data.
When galaxies of baryonic matter that look the same rotate at different speeds it is a sign that there is a difference between them.
The difference - apparently - is not in the laws of nature that prevail in them (if it is assumed that everywhere there are different laws of nature, there is no point in looking for laws of nature) and in particular not in the laws of gravity.
Therefore the difference must be something other than the laws - something that is there and causes the differences.
This something is called dark matter.
As mentioned - after the existence of a gatekeeper - several conclusions were drawn from its existence and these conclusions were confirmed experimentally.
So you may not have an opinion on dark matter but that is no reason to express that lack of opinion.
In fact - all the "opponents" of dark matter have no opinion on the matter because they never voted:
1. Not about a logical error in the assumption of dark matter
2. Not on findings that are in conflict with the dark matter assumption
3. Not about an alternative theory
In fact - all objections to dark matter are vapors.
There's no reason to let off steam at every opportunity.
To Michael and friends,
I have no knowledge or opinion about dark matter,
But I'm asking for clarification on the logic of the dark matter evidence. Take 30 by Michael: Gravitational Idush will be discovered in the absence of baryonic matter,
Different velocities of galaxies have been discovered
The astrophysicists are unable to explain this using the relativistic theories, so they devised a new theory: suppose there is another player in the astrophysical field. And how will we prove it, if not through the emptying and the different speeds?
And regarding the opinion of a minority versus the opinion of a majority, the minority must make its voice heard at every opportunity, so that it does not lose.
Remember the voice of Aristarchus from the third century BC, who claimed that the planets revolve around the sun which is a huge ball of fire. Because the need was not voiced enough, it was lost for two thousand years.
Ghost:
The MOND theory not only doesn't make dark matter redundant, but it also doesn't get along with normal matter.
I have explained this many times here on the site.
Okay, since I wasn't given free rein to comment as I wished,
I will respect the site's wishes and will not respond.
Shabbat Shalom
Sabdarmish Yehuda
Michael
Regarding Ehud's words about there being no dark matter, what do you have to say about the MOND theory
As I understand it, the theory (in its explanations) makes the presence of dark matter in the universe unnecessary?
And another reference to the subject:
https://www.hayadan.org.il/no-need-for-dark-matter-3110076
Yehuda:
In another discussion you asked why spend money on unproven technology.
In other words - an expression of understanding that the more confident you are in a certain thing - the more money you are willing to spend on it.
This is the answer here as well.
I guarantee that a similar amount of money will not be spent on trying to find little angels that accelerate the rotation of galaxies or on "interstellar cyclones" that contradict the laws of physics and the facts.
The site is a site of popular science, so it tries to publish only scientific things.
His way of knowing what is scientific and what is not is to rely on sources where it is known that the scientific standard is maintained.
It is not intended to support the steams about the scientific theories nor to "promote sales" of theories that do not meet the scientific standards in that they are not reasoned or have not been subjected to peer review.
I'm sure you don't see Science or Nature as unscientific newspapers and I'm also sure that as soon as they publish your views (and I can assure you they won't but you're welcome to try) my father will be happy to do so too.
In the comment section - as long as you express yourself in a civilized manner and as long as you do not repeat things more than - say - three times (a number beyond which you already start to become a troll) you are allowed to express opinions that do not meet the strict scientific criteria.
Yehuda,
You wouldn't make meatballs or anything else, for the simple reason that you don't have enough knowledge on the subject. Your pretense of presenting yourself as someone who brings into the world an innovative and brave theory is simply pathetic.
The pressure theory was proposed back in the 19th century and was abandoned a long time ago because it has no basis and no success.
You take an old theory, which is based on classical physics, does not consider quantum theory or relativity, and dare to present it as a theory "for the brave", which you developed yourself.
I think it's time to stop your unvarnished arrogance.
Welcome back Judah,
Like it or not dark matter and energy are currently (currently a second time)
The most mathematically supported models, observations and predictions as an answer
to the speed of rotation of the galaxies, gravitational contraction and the expansion of the universe. all of this
Still doesn't bring them closer for example to what we know about geology
of Mars or "multiple observations and angles" models.
I find it hard to believe that physicists who support it (including Michael) are not aware of this
which is an evolution of a model in which many surprises lie.
Specifically regarding the pressure changes model you propose (and from what I understood from it),
It lacks several elements to explain the structure and movement of galaxies, such as
For example additional forces that create the rotation, the distribution of the arms, interaction
Between galaxies and many, many more calculations. If I'm not mistaken then also predictions.
At the end of the day it's still a lot of work. Except that there is almost no chance of getting in
To the accepted model today (including all the calculations) and come out with something different, but
If so you have a group of scientists, labs, telescopes air time and probably
Also a considerable budget.
Anyway, I wish you success.
Why is it that tens of billions of dollars are spent on something that is so sure of its existence for the sake of trying to prove it (the Zern accelerator, research spacecrafts, and observations in deep mines for years)?
Isn't it time for the site to prove its scientificity by removing the censorship on opinions contrary to the scientific consensus instead of canceling them outright?
Isn't it ridiculous that you are willing to hear anything about dark mass except that it doesn't exist?
If I will not be allowed to express my opinion, I will respect your wish, although I will do so with regret.
I will only point out that my opinion supports the spirit of commenter Ehud's words.
So what do you say, can I speak my mind without fear of it being removed?
waiting for your answer
Good night
Sabdarmish Yehuda
It is possible that Einstein's words, although said in a different context, are a prediction
Accurate for the study of dark matter and energy: "It's like hunting birds
At night in a city where there aren't many birds"…….. a bit of humor.
You should stop looking under the flashlight (even if it is located in a mine 1 km underground)
The baryonic matter is the exotic/unusual matter and therefore also the "less interesting" when it comes to exploring the universe.
We are dealing with three electromagnetic/weak/strong forces that shape probably only 1% of the matter in the universe and from them we try to project what happens with the dark matter.
Dark matter and bullion have a force (assuming that force is not a misleading concept here) in common which is gravity which makes it difficult to study.
It is likely that there are other significant forces perhaps no less than gravity in the interaction of dark matter with itself
The correct way to study dark matter is to try to study its distribution in our immediate astronomical environment with high resolution by sensors that are very sensitive to the phenomenon of gravitational dusting, I did not make calculations to find out if the limitations of known physics would ever allow the existence of such a practical experiment
And when we come to investigate dark matter with the few tools we have, we must take into account that because we are thug scientists our physics is the physics of a remnant and not of the main thing.
sympathetic:
I did not claim that science is a democratic field.
I argued that language is a democratic field and you are not using language correctly.
The fact that most scientists are convinced and those who are not convinced have no alternative is something that must be said every time you express disdain on the subject because the readers of the website here do not know the material enough to form their own opinion and the logical way - for them - is to accept the opinion of the majority of scientists.
First, comments about science: science is not a democratic field. In science, the majority does not decide. A sentence such as the absolute majority of scientists believe in its existence is not scientifically convincing, it is a sociological argument. Regarding the authority of scientists: there is no sanctity in what scientists say, on the contrary even the greatest of them were wrong and admitted their mistake, this is what makes science a fascinating field. If you think that what scientists say is necessarily true you are essentially turning them into rabbis. The authority of scientists does not come from their status but from the strength of their claims and for "dark matter" the claims are flawed.
A more solid evidence of the existence of dark matter was finding it in the laboratory, which has not yet happened despite what is written in the article, by the way there were many cases in the past where scientists claimed to have found the dark matter and their claims turned out to be falsehoods. That is, even though they have been looking for it for over fifty years, the dark matter has not yet been discovered in the laboratory.
If the existence of the dark matter was due to a certain theory of elementary particles, this would give confirmation of its existence, but the attempts to find what the dark particle is were also disappointing. You mentioned the inability to explain the observations using only baryonic matter... Therefore, this is the invention of a new matter that does not arise from the theory of elementary particles that we know until now. In my opinion, fundamental differences of the theory of elementary particles or an ugly problem for the theory. Therefore, dark matter is not suitable for physical theories outside the field of astrophysics.
And in conclusion if we talk about Carthage it can also be noted that Carthage should be destroyed. No, the discussion was completely sterile, I would not have raised the issue.
By the way, I have no problem with the fact that the dark matter is not directly observable, I have a problem with the fact that it was invented only to explain the results of experiments, no confirmation for it has yet been found in the laboratory and does not fit into the body of scientific knowledge.
See, Ehud,
The facts are as follows:
The existence of dark matter is hypothesized due to the accelerated speed of rotation of galaxies.
It was enough to think that such a thing was possible.
Later - its existence was confirmed - both by gravitational perturbation and by the differences in the degree of acceleration of the galaxies' rotations (since - contrary to various laws of gravitation which are supposed to operate in the same way - the matter - including the dark matter - is not required to be uniformly distributed).
Therefore, the predictions provided by the dark matter theory as a gatekeeper for the first time came true and in fact today - the overwhelming majority of scientists (including the partners in the development of MOND and its refinements) believe in its existence.
A slightly more noticeable disagreement exists as to its nature when a (very small) part of the scientists believe that it is possible to be satisfied with baryonic dark matter (so far the class of dark matter is exactly - but exactly! the same as the class of stars that were discovered through their gravitational effects) and the majority thinks not (we will see the effects of the passage of a body through A body that is discovered in the Slingshot cluster and due to the fact that such an amount of baryonic matter was supposed to give birth to more stars - both in general and in particular in a galaxy collision).
Even if a point were to claim that he is an alien (dark matter) you would not claim that he does not exist but at most you would claim that he is an ordinary person (a thug). If people would also report their geographic location here accurately and it would become clear to you that different people were sitting in the same place, you would assume that a change in the aforementioned assumption would also be required here.
The fact that you define the conclusion of most scientists as unscientific is … (I don't have a suitable word).
Since language is a matter of conventions and most scientists define science differently than you then - by definition - the majority determines.
In any case, as mentioned, you should not turn any mention of the dark matter into an opportunity to say that Carthage should be destroyed.
http://he.wikipedia.org/wiki/מלבד_זאת_אני_סבור_שיש_להרוס_את_קרתגו
Itzik:
Yes.
I have already said on some occasion in the past that it would have been better to call this material transparent and not dark.
https://www.hayadan.org.il/underground-search-returns-uncertain-results-2212096/#comment-258032
Do not understand. It says "According to estimates, what we know today as "dark matter" (dark because it does not reflect and does not absorb light in any way)"
If the material is non-reflective, i.e. neither reflects light nor absorbs light, then the photons pass through it without being stopped, so it should actually be transparent, right?
Well, really, both the particle is dark and the mine must be quite dark, it's a problem to find something bigger than a particle there.
I'll start from the end: I didn't really think that there was a mistake in the article and it should have been written 500 years instead of 5
It was a kind of humor (which doesn't always go over well online).
Regarding the dark matter, I agree because we have had the discussion more than once and there is no reason to repeat it...
My goal was to point out that, unlike other physical theories, the dark matter theory is less (or not at all) based, so in terms of balance, this should be noted. The status of the planets is different from that of adding
Dark matter for theory (this is also relevant for you point) and it must be understood that not all physical theories have the same foundation.
point
I haven't seen you either, but I assume that you exist as a person. If someone came and told me that you are not a human but a green alien, in my opinion the burden of proof would be on him. If I understood your reasoning for siding with the dark matter, it is taken from the military field "it is what we have and with it we will win". Science doesn't work that way. Science is a skeptical practice that tries to find the problems and inaccuracies and thus evolve. If I told a reasonable person (who is the proper judge in your eyes) that there is a mysterious substance that no one sees but is there and for more than fifty years they have been actively searching for it, would they choose to believe me? Could it be that if I attached a prestigious academic degree to my name and told him that the words of his article in the name of science he would be more inclined to believe me?
What the public doesn't understand is that we don't see anything of what the universe is made up of according to physics. We do not see fields, particles, forces, etc. We do not see atoms, electrons protons photons. you can not see a thing.
We infer about them from measurements. The same goes for dark matter. So it's true that there aren't enough measurements for the dark matter, but for now that's what we have. Other explanations are less likely, and a reasonable person will choose the more likely explanation with all the caveats.
And in relation to response 19:
Saev is among the same majority I was talking about, so it is more likely that he will talk about five years and not five hundred.
I don't know if his prophecy will come true, but I have almost no doubt that this is what he said.
sympathetic:
I fully understand what a prediction is in science and the prediction I provided is a prediction.
I really don't care what this or that person drives.
This prediction stems from the understanding (which is part of the reason for formulating the theory of dark matter) that no change in the laws of gravitation will cause structures that look the same to behave differently.
The first extrasolar planets were not discovered by obscuration but precisely by their gravitational effects.
Until then, no planets had been observed outside the solar system, yet they added them "ad hoc" without fear.
The same goes for certain planets in the solar system.
But, and this is the most important thing - this was not the subject of any of the questions here and you simply feel the need to enter the debate about the very existence of dark matter even when there is no reason for it.
We've already had this debate.
I and most scientists agree.
You and a minority have a different opinion.
There is no reason to repeat it thousands of times.
I'm sorry but I'm not sure that you understand the meaning of confirmation or prediction in science. In science it is customary to talk about quantitative predictions not:
"Even the rotation speed of additional galaxies whose rotation speed will be tested will not correlate with the rotation speeds of galaxies that look like them (visible through electromagnetic radiation of course)." or
"There will be more cases of gravitational pollution around nothing" these two comments
They are not predictions, and in particular when there is a theory that is up to the mark, it determines the amount of dark matter according to the observation.
You are simply describing the problem we have encountered so far and therefore not claiming anything. In other words what was observed is what will be observed in the future. Quantitative science wants numbers.
Regarding the confirmation of a theory, it is not enough to invent new parameters for each observation, the exact sciences have to give a numerical prediction. In what you call confirmation there is only the description of the problem, not necessarily an indication because there is material that is not visible. I will explain it another way. It is possible that the theories so far are correct and there is new material that causes the observations to deviate from them or it is possible that we do not understand something basic.
Planets were observed by several effects among them: occultation which if I'm not mistaken is the more common one.
As you know, planets are not a new concept in the theory of gravitation, there were also ancients who observed them and therefore I have no problem with a theory that uses planets. When presenting a theory that postulates an additional object that has not yet been observed or has not been used before in any theory (apart from the disqualified site...) the burden of proof is on the presenter to prove the existence of the object.
Surely you remember that it was the pressure of the site that caused the bodies to contract with a flying aim...
The case of both dark matter and dark energy seem to be simply damp and similar to the invention of the ether over a century ago. Neither did Maxwell's laws fit with Galileo's transformations nor did the observations (the final speed of light) match the experiment. Even in the case of the site, they invented completely new material to explain the experiments, and it turned out that the problem is in the formulation of the basic equations, that is, the theory and is not based on new material.
sympathetic:
I think my words are presented in a completely balanced way.
Questions were asked about the existing theories - the ones on which the article is based and there was no sense in me talking about other things (and especially not about things that seem to me to be illogical in their own right and not just unsuitable for an answer for the reason I detailed).
The theory of dark matter is only a theory because that's what there is in science - only theories. It is confirmed by many findings that you repeat and ignore every time the subject comes up. The rotation speed of galaxies, different speeds for similar galaxies, gravitational swirl around nothing and even, to some extent, the results of the experiment in question here.
Want predictions based on dark matter?
1. Nor will the rotation speed of additional galaxies whose rotation speed will be tested correlate with the rotation speeds of galaxies that look like them (visible through electromagnetic radiation of course).
2. There will be more cases of gravitational pollution around nothing.
According to you - the theory of relativity has also failed in every system where planets have been discovered because of the movement they cause the sun as they revolve around it.
After all, we simply invented these planets to explain the movement of the sun and never observed them!
I'm sorry, but it doesn't seem serious to me.
The matter with the connection to the quantum theory (which you mistakenly called the theory of relativity) is also irrelevant.
How about saying that quantum theory failed because it doesn't fit with relativity or it failed because it doesn't explain gravity at all?
Don't try to argue with me about that because I don't think that's the case. I just think that the symmetrical picture you present is not correct either.
I don't know, but I guess...
These are semiconductors. The "dark matter" is supposed to pass through the detector and release charges in the semiconductor. The charges created a current that would measure and indicate that the detector had detected something. It is possible that the price is not what determined the type of detectors because there are only five detectors...
sympathetic
Is the cheap price the only reason? I'm sure the scientists thought of this before but,
Maybe other materials will yield better results? Or will they not produce results at all?
Do you know anything about it?
ghost moon
Regarding the sensors, I assume that germanium and silicon sensors are used because of their cheap price.
I also think there was a mistake in the quote at the end of the article. It should have been written
"We expect or certainly hope that in the next five hundred years or more, someone will notice a clear signal."
Michael
In my opinion, it is appropriate to present things in a more balanced way. The theory of dark matter is only a theory and it is
She has not yet received evidence to back her up. When inventing material that does not know how to explain the results of an experiment (or an observation in this case), then an important confirmation for the theory is its ability to predict the results of observations before they were made.
1) No prediction using dark matter has yet been made and observationally verified at a later stage. That is, today the dark matter theory has no predictive ability.
2) Dark matter itself has not yet been found even though scientists have been searching for it in laboratories for over fifty years.
3) The dark matter hypothesis alone is not enough to explain the velocity field of a galaxy, additional assumptions are needed for each type of galaxy. When the velocity field is measured, a distribution of dark matter that would have caused this velocity field is assumed retrospectively. That is, for each experiment I invent a distribution that will "explain" everything.
It is true that today there is no sufficient alternative to explain the incompatibility of the galactic observations with Newton's theory, but this does not indicate that the dark matter theory is correct.
It is also known that apparently the equations of general relativity are incorrect because they do not fit with the theory of relativity. The existing theory of gravitation falls apart both in the galactic realm (need to invent dark matter) and in the cosmic realm the need to invent "dark energy". It should be added that there is currently no satisfactory explanation why gravitation is fundamentally different from the force string, it is a much, much weaker force than the other three forces.
The dark energy is supposed to be found in the entire universe and it is expressed mainly between the galaxies and not in the content.
It does indeed act the opposite of gravity and therefore the opposite of dark matter.
The galaxies make up a very small part of the universe which is mostly empty.
Dark energy, therefore, is not a significant component of the galaxies themselves and most of its "weight" comes from outside the galaxies.
It is thought that dark energy limits the possible size of galaxy clusters - that is - when the cluster is too large - it accumulates and overcomes the force of gravity and prevents it from accumulating more galaxies.
Thanks Michael for the detailed answer,
If I understood correctly the (estimated) role of dark energy then
Thanks to which the expansion of the universe is accelerated and it is a kind of opposite of gravity
(If we say it in non-scientific language). The question is whether the dark matter occupies 22%
(about) the total mass of the galaxy, and this in order to "unite" and make the galaxy
to turn at a certain speed, where is the place and function of the energy
The eclipse in the galaxy?
And if the dark energy plays an important role in the expansion of the universe and it catches
74% of the galaxy, because in the expansion of the universe it fulfills the opposite function
Which one does it fill in the galaxy (Likud and Tirvan)?
What does the correct order here look like?
questionnaire:
Any body of normal matter that is not a black hole - emits or reflects light.
Any body made of ordinary material also hides light.
The estimated amount of dark matter is not 23% of the mass but of the total mass and energy (where the vast majority is dark energy).
There are galaxies where its estimated amount reaches a thousand times (!) that of normal matter.
Therefore, normal matter (baryonic) probably cannot fulfill the role of dark matter.
In addition to this - the evidence of the Slingshot cluster that I pointed to earlier shows that the dark matter of two colliding clusters continues to move unhindered while their apparent mass creates collisions.
A sun - at the end of its life - can roll in a number of different ways depending on its bearing.
If it is very massive - a part of it that is not blown out in a super nova explosion - can become a black hole and then this part will not emit radiation (it will not emit radiation itself but in most cases it will create effects in its environment that do emit radiation).
If it is not so massive, it may fade into all kinds of stars, most of which will continue to emit one or another energy for a long period of time - which may also exceed the lifetime of the universe.
Is it possible for a (spiral) galaxy to contain planets, moons
Asteroid belts and other objects that do not emit or radiate back
Radiation in sufficient quantity for us to absorb it from here?
And if the answer to the first question is positive, is it possible that they are tired overall?
Which ones will reach the area of 22% of the total mass of the galaxy?
And a final question: Is it possible that there are stars with masses of suns
Which do not emit different radiations as suns? something like "windows off"
Which are not absorbed due to the distance and maybe even "turned around" by the planets?
Thanks
A dark matter mine in Minnesota?
This is good because the reservoir is within the borders of the United States and then they will simply send a mining company instead of an entire army to conquer a foreign country in the Middle East.
There are 4 forces in nature: the weak force, the strong force, gravity, and electromagnetic.
When it is said about the dark matter that it is probably a force with a weak reaction or that it acts in the weak force, they mean that it interacts only in the weak force (and gravity) and not in the other forces.
Washing:
First of all - I don't know your and Eran's shared history, but as far as I understand, you haven't made a name for yourself as a troll here yet.
In relation to your question (4), the reason why they think it is dark matter and not a mistake in the gravity formulas is that apart from the increased rotation speed (usually - not always) of the galaxies there is a lot of other evidence none of which can be explained by any change in the gravity formulas.
The main evidences that are not compatible with a change in the gravity formulas are of two types:
1. We observe gravitational churning around regions with no or almost no visible mass. An impressive example of this phenomenon is found in the sling cluster - http://en.wikipedia.org/wiki/Bullet_Cluster But in almost every galaxy the phenomenon is seen on one scale or another.
2. The rotation speed of different galaxies that look similar in terms of the apparent mass distribution is different. Such a difference must arise from differences in the galaxies, but since there is no difference in the distribution of their visible matter, the difference between the galaxies must arise from something that is not visible matter - namely - dark matter.
There is, for example, a galaxy whose rotation speed of its stars exactly matches the existing formulas, and therefore it is concluded that there is no dark matter in it.
http://en.wikipedia.org/wiki/Messier_94
We are paying attention
The galaxies are spinning too fast
If it was that simple they would have done it already
And as I said in response 4
It could be that physicists' mistakes
Shaiva,
If it causes a gravitational effect, and is 23% of the universe, then we should already have noticed it, and its effects...
It is enough that we put a sensitive weight and weigh a bone, as soon as the particle passes by it, the weight of the bone will change.
It may be complex things that are difficult for us to understand...
On the other hand, it could be bullshit and not true, but it's the only explanation we have.
Roy,
From what I understand they say that the material simply does not affect electromagnetic waves like normal material
So you can't see it but you can feel its gravitational influence
But on the other hand black holes can't be seen either and you can only feel their gravitational influence
And we know how to find you
I think the problem is that we are limited by the human imagination
which is enough to understand Newtonian physics and a little beyond
But as soon as we get into more complex things it's just hard for us to imagine how they work
I don't understand something here...
On the one hand, they claim that it is a "weak reaction" meaning that it reacts with difficulty and does not absorb light.
On the other hand, it is responsible for the shape of the universe, and the force that rotates the axes of the galaxies.
Now, if he makes them rotate, he exerts a force on them that can also be measured, even on Earth. When the particle passes by an object it has to exert a force on it, but if it doesn't exert a force on it, how does it make the galaxies rotate?
Could it be that he is a prejudiced and racist particle that does not cooperate with anything smaller than galaxies?
All the dark matter comes from calculations, simply to balance an equation they added a new variable X and called it the dark matter...
Eran,
Everyone tells me I'm a troll and I never understood why
At a certain point I started adding reservations about everything I say
But still everyone tells me I'm a troll
Someone should write a guide on how not to be a troll
For 4 Sakhtein on self-awareness. A self-aware troll is no longer a troll - but a thinking person.
: )
I don't know physics
But I know that physicists don't understand gravity at all
We don't really understand why gravity is weaker than the other three forces
In fact, all we know about gravity is to calculate its effects in certain cases
So it seems very pretentious to me to simply add more mass so that the formulas we have today will work
Maybe the formulas are just not perfect
But then again I'm not a physicist and just as I don't like it when someone starts selling words about my profession
That's how I'm sure physicists don't like it when idiots like me start cooking up theories
For someone, even dust reflects light..
How do you know that the matter is not simply gas or dust that is thin enough not to block the light of the stars, but abundant enough to provide gravity and of course it has no light of its own? (because it is not matter inside a star)
We will never get all the answers about everything and it certainly doesn't make sense to think that here is a solution
Something so now there will be answers to everything. 9 years? So another 9 years, another 50 years
As long as it takes, in the end they will find out, that's how science is, little by little we will reach Eilat.
My question is why germanium and silicon sensors, what is special about them?