Comprehensive coverage

Probing in the dark for dark matter

Until recently, physicists pinned their hopes on particles known as WIMPs, but following recent disappointments, they are looking in other directions

A simulation of the Milky Way galaxy. The blue halo around it comes to illustrate the estimated distribution of the dark matter around the galaxy. Source: ESO/L. Calçada.
A simulation of the Milky Way galaxy. The blue halo around it comes to illustrate the estimated distribution of the dark matter around the galaxy. source: ESO/L. Calçada.

By Lee Billings, the article is published with the approval of Scientific American Israel and the Ort Israel Network 08.11.2016

Physics again missed a meeting planned long in advance. In the most recent and most sensitive searches so far for the particles from which dark matter is hypothesized to be made - the invisible substance that may contain 85% of the mass in the universe - again nothing was found. It is possible that these elusive particles, called "wimps" for short (WIMP's, literally: "thirty", English initials of their name), hide better than the physicists thought. But it is also possible that they do not exist at all, meaning that there is a fundamental and deep flaw in the explanations with which we try to understand the universe. Many scientists continue to hope that improved versions of the experiments will find evidence of their existence, but others are reexamining ideas and approaches about dark matter that for a long time were considered unthinkable.

The first disappointing result in the summer of 2016 came from the large underground xenon experiment (LUX). This experiment was based on a facility centered on a third of a ton of liquid xenon cooled to a temperature of minus 100 degrees Celsius. To protect this detector from most radiation contamination it was placed inside a water tank and buried half a mile deep under the Black Hills of South Dakota. The researchers waited for more than a year for flashes of light that were supposed to be emitted from wimps hitting the xenon nuclei. On July 21, 2016, they announced that no such flashes were observed.

The second disappointing report came on August 5, 2016 from the Large Hadron Collider,LHC, of the European Organization for Nuclear Research, CERN. This facility, located near Geneva, is the most powerful particle accelerator ever built. Starting in the spring of 2015, they tried to find wimps with his help through collisions between protons at unprecedented energy levels and at a frequency of billions of collisions per second: conditions that broke the limits that particle physics had reached before and brought it into new realms. Early in the experiment, two teams discovered an anomaly in the results of the subatomic collisions: excess energy that hinted at new physical phenomena that wimps might be causing (although even then, admittedly, this was only one among other exotic possibilities). But as the particle accelerator produced more collisions and more data was collected, this anomaly became blurred, indicating that the early results were nothing more than statistical aberrations.

These two negative results together are a double-edged sword in terms of dark matter research. On the one hand, they clarified certain limitations regarding the masses and the degree of interaction of the wimps, in the light of which it is possible to design a new generation of detectors that could increase the chances of success. On the other hand, they ruled out some of the simplest and most popular models of wimps, which raised new concerns that the wimps model is nothing more than a decades-old deviation from the right way to find dark matter.

Edward (Rocky) Kolb, a cosmologist who currently works at the University of Chicago and who helped lay the foundations for the wimp hunt in the 70s, previously declared that the 21st century's teens would be the "decade of the wimps." But today he admits that the search did not progress as planned. According to him, "we are in greater darkness today than five years ago regarding dark matter." So far, he explains, the response of most theorists has been in the style of "a thousand wimps will bloom": they have built increasingly complex and exotic theories to explain why none of the detectors have been able to discover these particles even though they are supposed to be so common.

Hunting for wimps has two interrelated theoretical reasons. The first is that these particles are naturally derived from one of the most popular extensions to the Standard Model of particle physics, according to which they should have formed shortly after the Big Bang. The second is that, according to the most direct calculations, if such primordial wimps do exist, their quantity and behavior nowadays correspond almost exactly to the quantities and properties of the dark matter that the observations show. This match (known as the "miracle of the wimp") is the reason why the search continued for decades. But now there are theorists who question the validity of this model.

For example, in 2008 they showed Jonathan Peng וJason Kumar, two physicists then working at the University of California, Irvine, how a phenomenon known as "supersymmetry" could create a hypothetical family of particles much lighter than wimps and with much weaker interactions with ordinary matter than those attributed to wimps. "The result with these particles is the same amount of dark matter that we see today, but they are not wimps," says Feng. "This idea causes an upheaval in physics because it stands on equally good theoretical foundations. we call him 'The miracle of being free of wimps'. "

Following the weakening of the theoretical foundations for the simple models of wimps, along with the long list of discovery efforts that all came to nothing, Feng and many others began to consider the possibility that wimps are part of a more complex picture: a hidden realm in the universe, full of dark particles that interact with each other in an array of dark forces, And maybe replace dark charges with flashes of dark light. Such models, of entire "dark sectors" in the universe, allow researchers to play with many more variables, which allows them to be built to fit the increasingly strict factual limitations following the accumulation of new data about dark matter. The downside of this much flexibility is that it is very difficult to check the correctness of these models.

"With the dark sector we are free to invent almost anything we want," he says David Spergel, an astrophysicist at Princeton University. "Without the 'miracle of the wimp' that guided us in the past, the space for possible models is huge. It is a playground in which we do not know what to choose from the possibilities it offers. In order to know where to continue, we now need additional clues from nature."

There are physicists who, following the clues from nature, have completely abandoned the idea of ​​wimps. For example, it is known that the elusive particles called neutrinos appear in nature in three forms, or three "flavors". Although these three forms do not have enough mass to explain dark matter, but since they nevertheless have some mass, they are an opening to the possibility that there is a fourth form with a greater mass, known as "barren neutrino". "Almost all mass-creating mechanisms in neutrino particles require the existence of sterile neutrinos, and it is quite easy to explain dark matter using some of these sterile neutrinos," says Quark Objection, a theoretical physicist at the University of California, Irvine.

Another regular candidate to star in possible explanations of dark matter is a so-called hypothetical particle Axion. It is a particle that should have weak interactions with ordinary matter whose existence was first hypothesized in 1977 as an explanation and solution to asymmetric quantum interactions that seem mysterious without it. To explain dark matter axions need to be found in a relatively narrow range of masses and be much lighter than wimps. "If we don't find wimps, theoretical physicists will simply switch to betting on the axions," he says Peter Graham, a physicist at Stanford University.

Apart from wimps, dark sectors, barren neutrinos and exions, there are even more exotic possibilities that might explain dark matter. These are possibilities that are currently on the fringes of physical thought, and they include primordial black holes, extra dimensions, and the possibility that there is some error in Einstein's theory of gravity.

Different dark matter physicists tend to favor different candidates, but the biggest problem that worries many of them is not that the idea will eventually turn out to be flawed or a complete mistake; The observational evidence that dark matter appears to exist is extremely strong. The problem that worries them is that the identity of dark matter will simply turn out to be irrelevant to other great mysteries in physics, so that solving the dark matter puzzle will not open new paths towards understanding the true nature of reality.

"We want dark matter not only to turn out to be something that does exist, but to provide answers to unsolved problems in the Standard Model," says Jesse Thaler, a physicist at the Massachusetts Institute of Technology (MIT). "Not every new discovery can be an important that suddenly makes the theories fit together much better. Sometimes new particles just make you say, 'Who ordered this?' Do we live in a universe where each discovery leads to deeper and more fundamental insights, or a universe where certain parts fit together easily, but not other parts? Dark matter leaves room for both possibilities.”

64 תגובות

  1. I looked at the video in question, and it does not match what Yehuda says.
    The standard kg did not decrease by 50 micrograms.
    When they created the standard kg, they created another 40 standard kg with it and distributed them around the globe. But before that, the mass differences between them were measured - and recorded.
    In 1948 they were assembled again, measured, and compared to the old records it turned out that the differences were created. The biggest difference between kg number X and kg number Y reached 50 micrograms. Note: this does not mean that their mass is smaller or larger. Both may have grown but not equally. Both may have been reduced. One may be 30 micrograms larger and the other 20 micrograms smaller. It is impossible to know the exact picture.
    Therefore Yehuda's "explanation" that the mass is 50 micrograms smaller is unnecessary. not relevant Suppose it were true: then all these masses should have decreased to the same extent and then the difference between them would have remained constant.

  2. Yehuda

    I don't know since when you read a YouTube video, but it was for those who are interested in a quick and simple overview of the subject. Not for those who want to understand the matter in depth. We would think you would be interested in understanding in depth here but it turns out not to be the case. I never sent you to read it anyway.

    To point out that a person does something he does is not to go down personal lines. It is directly related to the claims you make and why you do so. Most of the people here are already familiar with your professional ethics, but not necessarily all of them, and it is desirable that wherever you present your teachings, there will be someone who will take care to point out the matter. I admit that I don't always have the strength to do it, so I don't, but that doesn't mean it shouldn't be done.

  3. Woking
    You sent me to read it"
    This is evidenced in your second to last comment.
    And since you are moving into personal, wretched and defamatory lines, then for the sake of good order it is better that we stop. We explained what we had to say and I see no point in continuing our conversation. We don't have to agree.
    So bye Mr. Woking
    Sabdarmish Yehuda

  4. Yes Yehuda

    The Science site is a popular science site. It is not a site that publishes scientific articles. If you don't understand that I really don't know how to help you or explain anything to you. If you think you can understand a subject in depth and worthy of a letter in Hidan or the New York Times then you are hopeless and your understanding will always be poor and superficial.

    This news in the New York Times (or anywhere else where it was published (there is no shortage)) is not a stupid or misleading news regarding its main topic, but it does not say what you think it says because you are only addressing a small point where it is wrong, misleading and confusing (and ignores the main issue because it does not serve your agenda). Beyond that, time and time again you avoid going deeper and reaching a deeper understanding every time someone tries to make it clear to you. It can be clearly seen from this that the truth about this matter is not of interest to you, but only your desire to be able to imagine that you live in a world where there is justification for your crooked perception. This is actually the only reason you ask us to stop our argument here (this is also the difference between us, I came with the intention of debating and you came with the intention of arguing, i.e. in advance you had no intention of trying to understand what you were being told).
    It is not clear to me what you are talking about and where you got it from because the only thing I sent you to read is this:

  5. So that's your answer???, on the science website what they said is actually a report of "a wrong, inaccurate and confusing report that comes from a letter intended (at best) to give the public that needs popular science a superficial overview of the subject, etc." end of quote. So I'm sorry Mr. Woking but I value science much more and absolutely do not think he takes the populist approach you claim. I'm sure that the New York Times also relied on news / a serious problem that was discovered, and the Federal Standards Laboratory in the US also does not think that this is just a stupid and misleading news, and there 1,500 scientists dedicate all their work to improving the methods for accurate measurement. Hiring 1500 scientists is a lot of money. But I have a feeling we won't convince each other so let's end our argument here. Everyone will live in their own opinions. And by the way, it is written before you that the polished silicon cylinder in the article you sent me to will not help as it is and the kg will continue to lose its weight.
    Good day Woking
    Sabdarmish Yehuda

  6. Yehuda

    Great, so your entire understanding relies on an incorrect, inaccurate and confusing report that comes from a letter intended (at best) to give the public that needs popular science a superficial overview of the subject, and not from a place that bothers to be precise in what appears in it and is intended for people who are interested in accurately understanding the subject. (not to mention that the real subject of the article is the change in the definition of the kilogram and not a (non-existent) discovery regarding the weight loss of the kilogram)

    Let's go back to my first response to you here and the wonder and wonder:
    "After all, your whole claim about losing weight is directly related to an inaccurate report in the media that the official kilo lost its weight."

    We will return a response back and hop:
    "You don't try to understand at all what they say to you" "You have no interest in learning anything"

    We will go back again to the same response from before, and hope here is a link and a suggestion for a link for those who are interested in delving into understanding the matter more.
    "This is for those who want a simple explanation of the matter (those who want to read in depth can go to the kilogram entry on Wikipedia):"

    When will you try to really understand what is measured in the measurements and what the above measurements mean?

  7. Dear Woking
    I understand very well what is written in the article, so let's understand together.
    Here is what was published on the science website at the time:
    ” when the kilogram loses weight
    Scientists around the world are looking for an alternative definition for the kilogram, after the basic unit of measurement proved unstable
    By New York Times 12.6.2003
    Direct link to this page:
    It seems that the cult of thinness has also attacked the kilogram itself: according to scientists, the standard unit of weight is losing weight, and this causes those involved in science embarrassment and confusion. The kilogram is defined by a platinum-iridium cylinder, cast in England in 1889 and kept under heavy security in an estate outside Paris. No one knows why it loses weight, at least compared to other weights, but the change has sparked international research in an attempt to find a more stable definition for the kilogram.
    Although the change in the kilogram is only 50 micrograms, less than the weight of a grain of salt, this is enough to disrupt scientific calculations. "It certainly doesn't help to have a standard that changes," said Dr. Peter Becker, a scientist at the US Federal Standards Laboratory, where 1,500 scientists are devoting all their work to improving methods for accurate measurement. End quote.
    Please, Mr. Woking, make of it what you will. I check and understand that as a result of the expansion of the universe, the density of my particles and gravity will decrease and therefore the weight of everything will decrease. point.
    Good Day

  8. Yehuda

    You just don't listen at all. Not trying to understand at all what you are being told. You have excuses for everything and have no interest in learning anything and doing anything on your own. You are only interested in standing your ground, not having to change anything and shout your screams. Is there any point in having someone answer you?

    May you be healthy. Continue to ignore and live where you are not.

  9. For miracles, Woking and others
    It is true that the speed of light is the greatest in nature, and as Mickelson Morley proved, it is also constant in every direction, but who said that this speed cannot change? What happened: God woke up in the bunker the first day "and God said let there be light at a speed of 299,792,458 meters per second and that's it!, and let there be light!" The end of the divine quotation. The speed of light can change on my side, and with it all of physics. In a million years it will be ten kilometers per second slower. That's what there is.
    Regarding the friction, the whole story is to join the launch of a heavy spacecraft just like the Israeli company is doing when they send a probe to the moon. After you get to space it is relatively cheap to get far.
    Regarding the correct kg, I don't know how they measured the deviation, but it fits exactly with my calculations, you have to please and consider.
    And finally, anyone who talks about pushing gravity will encounter the waves of laughter from Richard Feynman's listeners in his lecture in the sixties of the last century. Anyone who wants to go to Richard Feynman's lecture site on YouTube, it's easy to find, his lecture at Cornell University, this is the lecture that is exactly 55 minutes and 55 seconds long. There at minute 8-11 Richard explains the theory of pushing gravity to the laughter of the students at the time. Do you think that someone at NASA would risk their job in order to send a spaceship, specifically to an empty place in the space that the NASA will beep, beep, once a month, and then ask that the radio telescope system sit down and pick it up? How ridiculous will he look if Yehuda is wrong? All the good souls waiting in the corner will descend on him how he wasted NASA's funds. Trump will personally see to it that he is fired.
    But, what a beautiful and warm sun is shining outside, maybe instead of arguing it's better that we march!
    Good Day!
    Please respond gently, it's just science!

  10. Yehuda

    1) I have a feeling you don't really understand the meaning of c

    2) "I am interested in the result in the article that he lost 50 micrograms in a little over a hundred years"
    So that's it, that's exactly the problem. You are again repeating an incorrect figure here. He hasn't lost 50 micrograms in a little over a century. This is simply not true. You just don't understand the whole story of the official kilogram.

    A) Tell me, do you know how much it costs to send XNUMX kg on such a route?
    b) How exactly do you want her to send us data without working?

  11. Yehuda
    Regarding the speed of light, WD is right - the statement that it changes has no meaning. And there is something much deeper here - the speed of light is not a value that is detached from the rest of physics. This is the maximum speed of information transfer - and your idea does not deal with this at all.

    Regarding the essay, you received an explanation, and it is not a new explanation.

    Regarding Pioneer - do you think that if there was really a discovery here, then how many scientists from NASA would not jump for the Nobel Prize?

  12. Dear walking death!
    I promise you that if it is proven that the speed of light changes, the definition of the meter will be changed immediately, period. They will not let him continue to change and brag about the speed of light = as you suggested.
    Regarding your question about unicorns, I am not familiar with unicorns.
    Regarding the kg he lost from his weight. I am interested that the result in the article that he lost 50 micrograms in a little over a hundred years is consistent with the theory. SA is worth checking out. You need to carry out accurate weighing on very accurate scales. I'm sure there are scales like that. I do not have.
    Pioneer's anomaly is explained by the emission of heat from its shut-down nuclear engines. At first NASA said that it only explained a quarter of the slowdown, but rather in the opposite direction, later they said that it was actually in the right direction and even went up to about a third, then they said that in fact it explained sixty percent and only after many years they decided that it explained one hundred percent of the slowdown. With exactly the right intensity and direction. What is happening now?, now she is far away and we no longer perceive her. So why create an argument? We will send a small probe without atomic engines and without a source of excuses and see if it slows down.
    Two o'clock in the morning is approaching at the speed of light, so we will part as friends, even if there is no agreement between us.
    You can respond however you want, I'm going to sleep!
    Good night
    Judah ()

  13. Yehuda

    1) Since when are we supposed to treat phenomena that have no evidence as existing phenomena? We now also have to treat unicorns as an existing phenomenon because there is no evidence to show that they exist?

    a) Why don't you actually do it yourself?

    b) After all, your whole claim regarding weight loss is directly related to an inaccurate report in the media that the official kilo has lost its weight.
    I can't find a better source, so we'll go with this for those who want a simple explanation of the matter (those who want to read in depth can go to the kilogram entry on Wikipedia):

    c) Am I missing something? Are you claiming something deeper than that by any chance?

    d) If I don't understand and you claim in the event that this claim cannot be measured at all, then why should we even refer to it?

    2) The speed of light is defined as 299,792,458 meters per second. The meter itself is defined according to this speed. The definition of the meter is completely up to her. Therefore, the definition for cm is also like this. Even if the speed changes, a meter will still be a distance resulting from it (as well as cm). Therefore it will never slow down in cm or any distance as a function of any time whatsoever.

    3) The phenomenon of Pioneer's anomaly exists. The problem with your theory in this case is more that it has already been solved and has nothing to do with the friction you are desperately looking for. But if within the framework of your theory (which is not very comprehensive, let's face it) these evidences can be explained in another way, I have no problem with that (there are simply much better solutions at the moment).

  14. walking dead
    How did you determine that my model explains a phenomenon that does not exist? Did you measure and see that there is no change in weight? You have connections in the academy so go and arrange a measurement. Willing to bet with you on a meal for two that will result in weight loss. Even if you lose, I'll invite you, it's worth it to me because of the proof.
    Regarding the change in the speed of light by XNUMX cm per second over a year, you said "by definition this cannot happen" why?
    I promise you that the speed of light will decrease by one cm per second per year, if you want you can earn another meal for two.
    What about friction in movement in outer space, do you agree with that? It's not difficult to organize an experiment here, send a probe to a distance of several tens of astronomical units, turn off the engines, transmit a short beep every time and check if the probe slows down
    Good night Woking!
    Please respond gently

  15. Yehuda

    "Weight loss of about 0.43 micrograms per kg per year"

    So your model explains a phenomenon that does not exist?

    "The speed of light changes by XNUMX cm per second per year."

    By definition this cannot happen (at least not the way you defined it here)

  16. Yehuda
    As usual in the holy place you always confuse the mind. You are completely obsessed with Pushing Gravity, a concept that has passed away. You and Pushing Gravity are a hot couple.

  17. for miracles
    You wrote: "So maybe we'll call this substance of yours that fills the medium, and that we don't see, "dark matter?" End quote.
    Indeed, this is a claim made against many, that in fact I am replacing the dark matter whose existence I deny with another dark matter, my own.
    There is a fundamental difference between my dark matter - the pushing particles of the simple gravitouniverse, and the normal dark matter particles,
    Pushing gravity is made up of tiny particles that have all the properties of normal matter such as momentum, kinetic energy, friction and more, so it will be easy to put it to the test, on the other hand, dark matter is a matter that only has gravity and nothing more, neither friction nor opacity to light, so it is also very difficult put it through the refutation test to which every scientific idea must be put.
    Below are some examples of phenomena that the gravity pushing explanation predicts, which can be measured relatively easily, such as:
    -Weight loss of about 0.43 micrograms per kg per year.
    - Friction and slowing of movement in the "empty" space such as the "Pioneer anomaly".
    - The speed of light changes by XNUMX cm per second per year.
    And more.
    All of these can be measured and the idea can be put to the test of refutation, and then it will be possible to ask Yehuda to stop confusing the mind or maybe it will be accepted that Yehuda is right after all.
    Good Day
    Please respond gently.
    Sabdarmish Yehuda

  18. Yechiel
    Our "logic" is the result of three things - evolution, experience and education. Evolution has made it so that we look for a reason for every phenomenon. Experience shows that it is impossible to be in two places at the same time. Education shows that it is not so, not so... There are phenomena that do not necessarily have a cause, and there are particles that are in two places at the same time.

    "God" falls into the same category - and when there is enough education most people realize that there is no need for this invention.

  19. I have to state that I am not religious. Because you honestly think that there is some kind of influence. And there isn't.... I am an astronomy enthusiast and the level here is so high. I would be honored if you would invest some time in what I have to say. I realized that there is a situation where there can be a situation where two particles collide Although there is no contact between them and the distance does not matter. They are affected and influence each other... Can such an abnormal situation exist or is our mind simply unable to digest such a different situation. Because in the bases of our understanding we learned that one plus one equals two. And it is not logical in our minds to digest that this could be Three....and couldn't it be that the contact between the two particles could actually be dark matter that we haven't found yet...and is this inability of ours to understand such a situation which is not normal in terms of our understanding. It might be a situation of divinity....please don't jump on me about divinity...

  20. for miracles
    Newton's gravitation formula describes well a phenomenon that leaves a certain center and spreads in space. Hence the logic of the square of the distance. But she sins by not considering the fact that she may have a disturbance as a result of the passage through which she moves in her movement in space. What is meant, let's say light coming out of a lighthouse is also a phenomenon that moves according to the square of the distance, but there is also turbidity as a result of passing through the medium in which the light moves. This will cause the intensity of the light to be lost at a rate greater than the square of the distance, for example in the case of haze in the atmosphere, the light will lose half of its intensity every X km (depending on the haze) and this is in addition to what it loses as a result of the square of the distance. I argued that every phenomenon that spreads in space has this loss as a result of moving through the medium in which it moves. Likewise for gravitation. In case someone (Newton) wants to assume that there is no such disturbance, he actually claims that X is infinite. Assuming that X is not infinite, gravity will lose its strength in its movement in space much faster than the square of the distance. I checked and calculated and it is possible that the size of the aforementioned X is a single number of light years, so it would be correct to assume that, unfortunately, gravitation does not actually exist at distances the diameter of the galaxy (it seems to me that the diameter of the Milky Way is "only" about 100,000 light years)
    If my way of thinking is correct then it is not gravity that rotates the galaxies but something else.
    Hence, unfortunately, relativity based on Newton is also wrong at large distances.
    That's my opinion. Details on my blog, hopefully my explanation satisfies you. If not, I'm here (:))
    Please respond gently.
    Sabdarmish Yehuda

  21. Yehuda
    The diameter of our galaxy is about 200 thousand light years. Are you saying this distance has no effect on gravity? After all, if a body disappears, it will take a long time for it to have an effect on the other end.
    Regarding dark matter as an observation, I think you are right. What bothers me about your idea is that, as I understand it, you are changing a formula (which is not the correct formula for large distances anyway) - without giving any fiscal explanation. In addition - the correction of the formula does not explain phenomena such as group pollution.

  22. Miracles
    I'm not the only one mentioning Newton's formula, the entire explanation of the anomaly in the movement of galaxies is based on Kepler's and Newton's laws and you really don't need gravitational waves or GPS deviations to see the anomaly. At speeds in which galaxies are hundreds or thousands of kilometers per second, the deviation between Newton and relativity will be a fraction of a percent, on the other hand, the deviation measured in galaxies is hundreds of percent, for example in an average galaxy there should be a missing mass of about 1000 percent (ten times the visible mass) and not just a fraction of a percent therefore Let's not get involved in relativistic calculations and Newton is definitely enough.
    And regarding my previous response, do you accept the comment that dark matter is not an observation, but the deviation from Newton's formulas is the observation? This is a very basic thing.
    I'm done for the day and going to sleep
    So please respond quietly....(:))
    Yehuda Sabdarmish

  23. Yehuda
    You keep mentioning Newton's formula - but I don't think Newton's formula is valid for long distances. In Newton's formula there are no gravitational waves for example.
    Do you propose an update to general relativity?

  24. to the dark side
    There is no doubt that an explanation will have to explain all the phenomena occurring in the galaxy and there will be an advantage to an explanation that explains the deviation in motion as well as in motion. But also in many other phenomena. See my blog article 71
    Sabdarmish Yehuda

  25. is not that a loss.

    I checked. It is about the MACHO theory that tried to test the gravitational acceleration and it was rejected (overwhelmingly).

  26. Sabradamish

    Let's assume I understood.. In any case, what do you say about the fact that dark matter explains both the movement of galaxies and the gravitational contraction, these are two independent observations, which dark matter explains nicely (unless I'm wrong in what I wrote).

    He seems to send us two hints "I'm here", and then laughs to himself "Ha, you won't find me".
    A devious and dark creature...

  27. to the dark side
    The MOND theory is another possible explanation for the deviation in the movement of the galaxies, but Professor Milgrom said that if gravitation is not compatible with the fast rotational movement of the galaxies, then the explanation is not a problem of gravity but a problem of movement - Newton's second law at small accelerations. I do not agree with this explanation and there is even a galaxy that rotates exactly according to Newton whose motion cannot be explained according to MOND. Rather, it will be possible to explain its movement according to the dark matter. There is simply no dark matter in it.

  28. Miracles
    "Dark matter is not a scientific claim, but an observation. The existence of WIMP is a scientific claim" end quote.
    Sorry but dark matter is not an observation.! The deviation from Newton's formulas is the observation. When you look at galaxies you see a deviation from Newton's laws, not dark matter!. Dark matter is the attempt (one of many) to explain the deviation from Newton's laws. The wimp, if it exists, would explain how (perhaps) dark matter works.
    That's my opinion

  29. I forgot the beginning of the paragraph:

    "Instead of inventing invisible matter [1], it is possible to explain the gap between the motion of the stars and the galaxy clusters by the possibility that the theory of gravity, or even our understanding of how force causes bodies to move - is wrong. An explanation based on this possibility was given in 1983 by the Israeli physicist Mordechai Milgrom.

  30. From a post of "Big science in small" that was published yesterday

    "Milgrom's theory, which is called MOND, an acronym in English for modified Newtonian dynamics [2], claims that Newton's second law [3] is inaccurate. Seemingly a problematic claim, since Newton's second law has been tested in countless experiments. But this is exactly what Einstein and Schrödinger did when they developed special relativity and quantum mechanics, respectively.
    These two theories claimed that the fundamental principles of Newtonian mechanics are imprecise, but the inaccuracies are such that they can only be measured under extreme conditions. In the case of the theory of relativity it is about high speeds and in the case of quantum mechanics for very small bodies.
    In the case of MOND, the significant quantity is acceleration. The deviation from Newton's second law can be seen, according to this theory, only in very small accelerations".

    Interesting, what do you think?

  31. Yehuda
    Dark matter is not a scientific claim, but an observation. The existence of WIMPs is a scientific claim that came to explain dark matter. This claim is at issue today. There are other explanations being tested.
    We do not find life on other stars today - does this mean that there is no such life and that we are wasting time on the search?
    Today we do not know for sure how life began - do you think we should stop researching the issue?

  32. For miracles and others

    The problem of the "scientific proof - yes or no" did not leave me and I researched and browsed until I came to Karl Popper on Wikipedia and indeed there he says:
    "Science can never prove the correctness of natural laws. At most he can put his theories to the test, try to disprove false claims, and choose a particular theory from among competing theories. Science explains reality through negation, why certain events cannot occur." End quote.
    Well… you are right Nissim and Vadrishti for scientific proof was…. Not modest to say the least.
    But, if Popper is right (as I believe) then let us examine whether the claim of the existence of dark matter is a scientific claim. Will someone be able to organize the refutation test for the dark matter? After all, it has no taste and smell friction and is transparent, etc. Other "shameful" properties that do not allow it to be in the refutation test, if the situation is like this, the dark matter will not be able to enter the category of a scientific phenomenon.
    Likewise with dark energy.
    But this is just my heart's rush, so please respond gently
    Good Day
    Sabdarmish Yehuda

  33. Miracles
    Regarding the continuation of your comment, I completely agree with you, but the question that is asked: what is the time limit when we must raise our hands and decide that this is it, there is no dark matter/dark energy?, are eighty years since the idea of ​​dark matter was raised not enough to reject it? In the shadow of this idea forever?, tell me you miracles, when will the expiration date of the idea be?
    And regarding the first sentence in your response, "Since when does anyone look for evidence in science?" There are proofs only in philosophy." End quote. Here apparently something acceptable is not understood by me. I will think, travel through Wikipedia and the scriptures, and respond.
    Thanks for an interesting response.
    Sabdarmish Yehuda

  34. Yehuda
    Since when does anyone look for evidence in science? Proofs are only in philosophy...
    From what I understand, various hypotheses are put forward for the nature of dark matter, and these hypotheses are tested. One hypothesis is that there are heavy particles that maintain a force that is weaker than the weak force. The article here says that for the time being they are unable to confirm the existence of these particles.
    Is this not a normal process in your opinion?

  35. for miracles

    I was surprised that you say that "no one is looking for "proof" of the existence of dark matter!!! There is a lot of evidence for this material." End quote.
    Here I realized that there was something I did not understand. I see scientists looking for proof of the existence of dark matter and can't find it, but in the same article and in the same lines you see scientists who wholeheartedly believe in dark matter and trust in its existence only by searching... Reinforcements for their believing souls.
    Maybe that's the difference between my optimistic friends and a pessimist like me. I see the glass half empty in evidence and you, my friends, see the glass half full.
    So I will agree with your next quote: "One of the most important things we have learned in science is - there are no simple explanations." End quote. And it's really hard for me to dig in. Late at night it's a good night
    Sabdarmish Yehuda

  36. No. Ben Ner
    You write: "What about dark energy? Which one do you get?” End quote.
    And the answer is certainly not. In my opinion, there is almost no connection between the movement of the galaxies and gravitation, so building dung mountains of dark mass and energy is not bound by reality. And for those who think that this moves Newton from his last bed, he is wrong because.... Newton did not know galaxies at all!!! All he knew was the planets up to the planet Saturn so he never said that even galaxies moving billions of times away from the solar system would move according to his formula. I'm sure he would deny it!! But out of respect for Newton, scientists talk about the movement of galaxies according to Newton. And for this purpose, they add as much dark mass as is necessary, and as we say in the upcoming Passover: "And everything in excess is fine" and then they also add energy (dark like the Passover wine) which is the minus of gravity and again as much as needed.
    Albanzo my friend is angry that I am talking about Newton's formula and not about the new relativity formulas of the dear Jew Einstein. Well, with the velocities and low density of the galaxies, I'm not far wrong if I insist on using the formulas of the dear and good Newton, may he rest in Eden.
    The truth is that I feel the darkness of the night taking over me so please respond gently
    And in these moments, let's not forget that it's only science and let's not forget the dark situation in which the Maccabi Haifa fans are currently in the game of Hapoel Beer Sheva against Maccabi Haifa where four unanswered goals were stuck in Haifa's hair, goals that must have made the hearts of the poor Haifa fans as dark as the dark mass.
    All the best
    Sabdarmish Yehuda

  37. to the dark side
    You wrote in your response: "The assumption that there is dark matter is based on gravitational flux and the movement of the galaxy, and these are two independent pieces of evidence. So it cannot be said that this is an unfounded assumption." End quote.
    First I will correct you because you have a small inaccuracy and that is that what you see in the galaxies is not "gravitational clutter" but rather "clutter". At its core, the air pollution does not only result from gravity, and associating it directly only with gravity may be a mistake. What do you think about air pollution resulting from a pressure difference?, from a density difference?, from a background temperature difference in different regions of the universe?
    One of the above reasons can cause both turbulence and pressure differences that will rotate the galaxy
    Sabdarmish Yehuda

  38. תגובה
    It seems to me that your approach is correct. The phenomenon I propose to take to explain the movement of the galaxies is really not gravitation but pressure differences. It seems strange to claim that there are pressure differences in our empty universe, but is it really that empty? Every cubic centimeter contains millions of particles such as neutrinos, axions, photons, cosmic rays, and more and more. All those floating in the space of the universe define it as a gas, and as such it has pressure differences that can last for billions of years. Their action to move galaxies, on my website I try to show that these pressure differences manage to explain the motion without the need for dark matter and energy.
    Sabdarmish Yehuda
    It seems to me that your approach is correct. The phenomenon I propose to take to explain the movement of the galaxies is really not gravitation but pressure differences. It seems strange to claim that there are pressure differences in our empty universe, but is it really that empty? Every cubic centimeter contains millions of particles such as neutrinos, axions, photons, cosmic rays, and more and more. All those floating in the space of the universe define it as a gas, and as such it has pressure differences that can last for billions of years. Their action to move galaxies, on my website I try to show that these pressure differences manage to explain the motion without the need for dark matter and energy.
    Sabdarmish Yehuda

  39. Why not devote an article to MOND-> TEVES-> entropy gravitation. Phys org magazine devoted an article to this.
    I have read everything I can understand about Bekenstein's theory, Milgrom's and Verlind's.
    I think their explanation is convincing in its simplicity. If I have to choose between a substance for which there is no evidence and a physical explanation of the origin of gravity, and why it changes depending on distance, I tend to prefer the second theory.
    I understood that there are even larger scales of clusters of galaxy clusters where this does not fit (yet) and therefore a scientist like ELBENZO may not support the above theory, but there are dozens of inconsistencies that are accepted as bridged.

  40. To Lorem Ipsum
    I guess the answer to your question is something like this:
    Only if a collision occurs at impact radius 0+- (!!!), between a dark matter particle
    and some atomic nucleus, the collision may cause the atomic nucleus to break, no
    Because of interaction A.M. but because of gravitational interaction.
    It is the breaking of the atomic nucleus as a result of the collision that will cause the emission of photons.
    And these photons the experiment is looking for.

  41. I did not understand a single thing.
    So we have something called "dark matter", according to the hypothesis these are particles that meet the following conditions:
    1. They have mass and gravitational interaction.
    2. They have no electromagnetic interaction, nor strong force interaction, nor weak force interaction.

    So why exactly are they trying to find their electromagnetic interaction in deep mines?

  42. To Judah
    You go against the dark matter,
    And what about dark energy? which one do you get?
    It is much bigger and much more problematic to explain and understand.
    Come on, charge.

  43. for miracles and others,
    I absolutely do not think that scientists are stupid and apologize if anyone took it that way and my question to Albanzo in my previous response if he thinks scientists are stupid should not have been asked and again I apologize for that.
    And for our purposes, I can't pull out a response to your words, Nissim, and I will do so after much thought. I have to understand why even though our opinions are opposite, each one is sure of his position. I know I'm in the minority but luckily science is not democratic and sometimes the majority can be wrong. I will write my response in a few hours because of previous assignments that I have to do
    Have a good week everyone

  44. Dark matter is a network of electrons and positrons, on which light moves, this is a theory of an Israeli professor that also explains what gravity is, and this means that Shinstein's theory has an inaccuracy, it's just a shame that most researchers try to rape physics with mathematics...

  45. Yehuda
    The one who says all scientists are stupid is you. Please, no hypocrisy 🙂

    You say that there is no evidence for the existence of dark matter - and this is an inappropriate statement for someone who claims to know what science is. Scientists look for evidence that supports the theory they believe in. But, usually, they look for lungs that contradict their theory.
    No one is looking for "proof" of the existence of dark matter!!! There is a lot of evidence for this stuff. Different scientists have different hypotheses about the nature of this substance, and that is what this article is about.
    No one says that "attempts to find evidence for dark matter have failed."

    I don't understand what you mean by changing formulas. A formula is a mathematical tool, not a physical explanation. Change the gravity formulas all you want - but what did you explain?

    And in my opinion, one of the most important things we learned in science is - there are no simple explanations. For your part - you should go back to Apollonius' and Hipparchus' epicycles and deferents. Why get involved with Ptolemy's additions? 🙂

  46. Yehuda,
    I understood that there are researchers who are trying to develop an alternative theory for dark matter,

    But if we are talking about the article, pay attention to what is written
    "The observational evidence that dark matter appears to exist is very solid evidence. The problem that bothers them is..."

    The assumption that there is dark matter is based on gravitational flux and the motion of the galaxy, and these are two independent pieces of evidence. So we cannot say that this is an unfounded assumption.

  47. to Albenzo
    You repeat your words over and over and think that dark matter is proven and exists, so why do you think all scientists are idiots when they keep looking for proof of its existence?? They believe in its existence like you but know that there is not even one proof of its existence.
    And it doesn't matter if these things are said by a professor from the academy or a high school student
    It's already after midnight so good night

  48. Yehuda,

    No matter how hard you try to pretend, you know very well that what you call "Newton's gravitation formula" was thrown into the trash more than a century ago. You know it was replaced by very advanced, very very accurate, and very successful models that include dark matter. You also know that there is countless evidence for the existence of dark matter, and that the difficulty with detectors is not in finding it but in understanding its microscopic structure. Just like until the beginning of the twentieth century, no one knew what the structure of the atom was, but that did not mean that there were no atoms.

    Finally, you also know that no one changes data - only the theories, and that dark matter was born precisely because it is part of a theory that fits the data with phenomenal accuracy. But what does it matter that you know all these things, you are only interested in covering your ears and shouting "simple universe! A simple universe!". The search for truth has no value in your eyes unless it is the truth that you have decided is true from the high school physics textbooks on which you base all your nonsense.

  49. This article summarizes what I believe to be one of the greatest problems of the human mind.
    We don't know what we don't know, so we try to explain everything with what we do know.
    We know 4 basic physical forces.
    We know that of these forces only gravitation affects on an astronomical scale, so we seek to explain
    The difference between the standard model and the observations by gravitation, ie the presence of (dark) matter.
    This may be the correct explanation, but it may not be.
    For example, it is possible that there is another basic physical force, weaker, that affects substantially only on a galactic scale, and therefore we do not see it in the physics of the bodies on the surface of the earth or even on the scale of the solar system. This force can explain the uniform rotation of galaxies and many other things we try to explain with dark matter.
    Solving the problem using additional physical force is just an example.
    The solution can be different.
    The main point is that we don't know what we don't know, so we insist on putting together a puzzle when we don't have all the pieces.
    This approach is not necessarily wrong, but it becomes problematic when we forget that we start from the assumption that we have all the pieces of the puzzle and therefore try to assemble it using what is available instead of looking in new places.

  50. You convinced me Benjamin May and I will respond

    In the first lesson in physics, every high school student learns the following fundamental rule:

    If the data measured in the field does not match what is obtained from a formula, the formula should be discarded and the data should not be changed to fit the formula.

    This is a fundamental rule in science, and perhaps, the most fundamental, in other words and to our eyes: if the data measured in the galaxies and the spaces between the galaxies do not fit Newton's gravitation formula, the gravitation formula should be discarded (or at least corrected) and the data should not be changed by adding dark matter, and when this too It is not enough then to add dark energy.

    So it's true that you have to take into account the fact that this formula, Newton's gravitation formula, has been around for over three hundred years and you have to give it credit and check the measurements over and over again, but it's been eighty years that they've been giving it credit, so you have to be brave and you have to understand that something is shaky in the formula and you have to make a change.
    What change will be made, is it a correction, the formula?, maybe replacing it with another?, and maybe... The movement of the galaxies is done as a result of another phenomenon that is not gravitation???

    This is not about not using the formula in simple calculations at small distances, in the solar system it is reliably proven!, there is almost no problem with it (apart from small relativistic corrections in GPS, in the precession of the planet Hema and Pioneer's anomaly that requires clarification). The problem mainly begins when we move to the galactic and intergalactic distances where we are dealing with distances billions and trillions of times greater than in the solar system. There is no reason in the world that the formula has to work there as well.
    Please respond gently
    Saturday today!, Saturday today!, Saturday...
    Sabdarmish Yehuda

  51. The article did not say that there is no dark matter. Not even that there aren't wimps. It is said that there are several possibilities being explored for dark matter. Including wimps.

    Maybe wimps are the dark matter. They may be part of it. They may not exist. At the moment a certain limit has been set for them. It may be that the border will move further and further until they are discovered. It may be proven that they do not exist.

    The neutrino mass limit is also constantly moving. The fear also arose that in the end it would turn out that there was no mass. In the end she was discovered

  52. The triple theory explains the effect known as the universe as a hologram, but as a lensing by-product of the variation of gravity depending on distance scaling, as a result and not as a cause. That is why the recently published article on a holographic universe - there is a holographic effect, but as far as I understand from the triple theory it is a result and not a cause.

  53. In the last 20 years, an upgraded general theory of relativity has been created that is quite well established and does not need dark matter. It is understood that its developers will not receive a Nobel, but it is quite established in my view. Mordechai Milgrom developed an empirical theory that does not explain the update of gravity depending on the distance scale called MOND. Jacob Bekenstein turned the theory into general relativity and it is called TEVES. Eric Verlind won the Spinoza Prize (the Dutch consider Baruch Spinoza one of their greatest thinkers and this is the Dutch Nobel) who showed from pure theoretical considerations of the arrangement of particles of matter as a system that carries information, and from the index of the order of the information entropy, how gravity originates and how it is updated depending on the distance. The theory is called gravitational entropy or entropy gravitation. From familiarity with the research in the field, I don't think that they think that Verlind is on the fringes.
    That's why the preoccupation with dark matter ended up fading in my opinion. There is a logical explanation for why gravity happens and why it changes with distance scaling. There are other unexplained end cases. That's how it always is in science. The triple theory MOND-> TEVES-> entropy gravitation explained at least several dozens of findings at the intergalactic level that agree with it.

  54. I fear that lately humanity is losing the ability to understand written clues.

    So if you've already written a comment, it's better to simply write "I told you so"... not elegant, but that's how it is
    At least the readers will understand………….. 🙂 :).

Leave a Reply

Email will not be published. Required fields are marked *

This site uses Akismat to prevent spam messages. Click here to learn how your response data is processed.