Astronomers who analyzed data transmitted to the "Pamela" research satellite detected a surprising phenomenon: a strong flow of positrons
Prof. Eli Waxman. Cosmic radiation
Astronomers who analyzed data transmitted to the "Pamela" research satellite identified a surprising phenomenon: a strong flow of positrons - which are a kind of "reverse electrons": they are equal in almost everything to electrons, except that their electrical charge is positive (while the electrical charge of electrons, as we know, is negative). This observation, of course, raised the questions of how these positrons are created, when, where, and how they move through the galaxy.
This is the place to say, that the very existence of these positrons is not surprising. The astrophysicists, in fact, expect a certain amount of positrons which are created as a result of the collision of the cosmic radiation with the interstellar gas. This collision creates a number of particles that, during their decay, create, among other things, positrons. However, recent observations have shown that there is a much larger flux of positrons in the universe than expected based on these collisions.
Many attempts to solve this riddle were unsuccessful, and thus speculations arose that the rather large amount of excess positrons is created in a process involving the "dark matter", which has various signs of its existence (especially the gravity it exerts, apparently).
Prof. Eli Waxman and his (then) research students, Kafir Blum and Boaz Katz, tried to find a solution to the mystery without relying on dark matter, while trying to understand how these positrons progress in the galaxy. Although there is no basic model describing the movement of positrons in the galaxy, they managed to find a way to calculate an upper limit for the amount of positrons that will be created and move in the galaxy, even without relying on any dark matter.
Data recently received from the AMS research satellite showed that, indeed, the flux of positrons does not pass the upper barrier calculated by the institute's scientists, but approaches it at high energies. Therefore, the source of the positrons is apparently cosmic radiation collisions in the interstellar gas, and there is no need to assume that some dark matter is involved in their formation. Thanks to this understanding, AMS measurements now provide important information about the escape of cosmic rays from the galaxy into intergalactic space.
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13 תגובות
Joseph
I don't want to loosen your hands, but on the other hand, the chance of a non-professional to achieve a scientific achievement is
very small. I don't remember any cases of "enthusiasts" who managed to achieve significant progress in science
Except maybe in the field of mathematics and also cases that happened hundreds of years ago.
Secondly, I don't believe that what is reached on this site is an understanding, not even an understanding of laymen
To explain the ear, Zvi is a professional with a deep understanding of astrophysics. to whoever
Outside the field, it is not only difficult to understand what is happening in the field, but it is difficult for him to understand the problems
and the constraints that exist in certain theories.
Regarding Professor Verlinda, you attribute greatness to him based on his winning the Spinoza Prize is a way
A little puzzling for evaluating scientific work... a little about his work:
1. He quit his job around 2010, by the way he took more
Change to publish it in a scientific journal. Since then for more than 4 years
(Victory in academic terms) He did not publish anything on the subject and all his publications
were done in other fields (together with his twin brother who is also a physicist
in Princeton). Verlinda's work has met with theoretical opposition
In several articles and I have yet to see articles that cancel the criticism of
his theory. An example of an article that refutes Verlinda's theory is
An article by the Australian Prof. Matt Wisser.
2. It is not clear to me how Verlinda's work denies the existence of the substance
the dark What Verlinda is saying is that Newton's equations can be obtained as well
The Einstein equations from thermodynamic claims about time-space.
By the way, the "guy" named Thanu Padmanabhan is not the first to claim this
The one you refer to (a computer scientist and seller) came up with these ideas before Verlinda.
By the way, the conceptual foundation of his work is the groundbreaking work of Prof. Hakab
Beckenstein on the entropy of black holes was the first to show a connection between
Time space for thermodynamics. After Beckenstein, Prof. Bill Unrao showed that it is possible
Map between acceleration and temperature.
4. By the way, Prof. Jacob Beckenstein, like many others, claims that they do not find a basis
to Verlinda's work and do not understand on what basis he makes his claims.
Posted about two months ago: http://heb.wis-wander.weizmann.ac.il/%D7%97%D7%A9%D7%99%D7%91%D7%94-%D7%97%D7%99%D7%95%D7%91%D7%99%D7%AA#.U2Oi3_l_vHQ
I believe that the talk in the existing theories is not physically deep enough. A clearer theory is needed.
I have pretensions to satisfy her. I am currently working on a PhD in power electronics in the areas of system theories.
I realized that they don't listen to you if you are not an academic and you don't have advanced degrees, and I completely refute this perception.
In the current way I got tools for writing articles and academic development that I didn't have before. I also found that getting articles is very difficult - a real test. I also unfortunately found that there is hostility between Arab editors and Israeli scientists. But this is a personal opinion and not a proven truth. Today I send to newspapers whose editor is not Arab. And it's a shame - I personally know and cherish Arabs who have achieved tremendous achievements in Israel and in the world and think that we can coexist with the right leadership.
In other fields such as high tech, they listen if you are not a doctor. We have dozens of entrepreneurs who have succeeded in equal scientific fields. That is, the world is open but difficult.
I'm not young either, maturity came late for me. The result of a combination of coming from a working-class home where the previous generation wants but doesn't have the tools to train not to make mistakes along the way, and my academic immaturity.
If I succeed I will try to answer these questions. To be successful is a combination of health, livelihood, peace at home, determination and the success of the theoretical model. We will try to remember that on this site you would ask the right questions along the way. If not, I have no doubt that someone will come. The words are said with sincerity and not with arrogance. Of course I may be wrong.
I was happy to read your comments. The truth is that I have a physical mathematical explanation that I believe is correct.
You all ask the right questions, which I think demonstrates that even laymen like us can understand.
Joseph
1. General relativity does not speak of the curvature of space and the curvature of time as two separate effects but rather as a curvature of space-time. In relationships it is simply not possible to talk about one of them without talking about the other - therefore the curvature of space in relationships necessitates the curvature of time.
2. In the approximation of weak gravitational fields, the significant curvature is actually in time, i.e. the slowing down of time in a gravitational field (the slowing down of time is indisputable and there is even observational evidence for this - in fact, some claim that general relativity is wrong and that only the slowing down of time exists and not the curvature of space - but this is a claim very unacceptable). In any case, the vast majority of those involved believe that general relativity is true in the classical limit and that space-time is curved.
3. Contrary to what has been said, the curvature of space does not require additional axes beyond xyz since relativity does not assume Euclidean space. It is possible that additional dimensions exist (according to strings and the like) but this cannot be deduced in any way from general relativity.
Shmulik,
As for Graviton.
Let's start by saying that at the moment there is no evidence of its existence and it is unlikely that you will find any in the coming years. The graviton is to gravity what the photon is to the electromagnetic force just as gravitational waves are the equivalent of light and since at this stage we have not yet directly located gravitational waves, we are very far from being able to locate their quantot if it exists. That is, in the meantime everything that is said about the existence or non-existence of gravitons can be based solely on theory without any visible hope of observation.
As for its theoretical existence or non-existence,
A few years ago I was bothered by the same question you raise:
If gravity is really not a force but an effect on space, why would it need a force-carrying particle? - After all, we know how it works at a distance - it distorts the space!
I turned to a person who understands a great deal about the subject and it turns out that you and I are not the first to think about it and the existence of the graviton is clearly not a necessary and direct result of the theory of relativity (not surprising, since the theory of relativity is a classical and not a quantum theory).
So why do Rabbis believe that Graviton exists?
The motivation for this comes from quantum field theory. Normal quantum field theory is done in Euclidean space. At a certain stage, attempts began to apply field theory in curved space, an idea whose most important result is Beckenstein Hawking radiation. The assumption was (as is assumed in relations) that the space is curved, but in a small enough area it is approximately flat and thus it is possible to learn from the "normal" quantum field theory about the behavior of the field theory in a curved space.
Later it turned out that such a treatment produces paradoxes, and from these they realized that the curvature of space cannot be smooth, but rather quantized on fairly small scales. The existence of a quantet in the curvature of space means a graviton - just as a change from a quantet in the strength of the electromagnetic field means a photon. So these paradoxes (the nature of which I do not know) show the existence of a need for the space quantot, that is, the existence of a graviton.
Note that the graviton will not in the least change the effects of general relativity since these live on large scales where you do not see the quantot curvature of space (just as light continues to behave as a wave if you do not look at experiments that force it to discover its quantum nature). What the existence of gravitons means is that in certain experiments, subtle enough, a quantum character to the curvature of space will be revealed. Meanwhile, we are very far from such experiments and, of course, many things are unknown about this because we do not have a complete quantum theory that unifies general relativity.
Joseph,
1. General relativity does not speak of the curvature of space and the curvature of time as two separate effects but rather as a curvature of space-time. In relationships it is simply not possible to talk about one of them without talking about the other - therefore the curvature of space in relationships necessitates the curvature of time.
2. In the approximation of weak gravitational fields, the significant curvature is actually in time, i.e. the slowing down of time in a gravitational field (the slowing down of time is indisputable and there is even observational evidence for this - in fact, some claim that general relativity is wrong and that only the slowing down of time exists and not the curvature of space - but this is a claim very unacceptable). In any case, the vast majority of those involved believe that general relativity is true in the classical limit and that space-time is curved.
3. Contrary to what has been said, the curvature of space does not require additional axes beyond xyz since relativity does not assume Euclidean space. It is possible that additional dimensions exist (according to strings and the like) but this cannot be deduced in any way from general relativity.
Shmulik,
As for Graviton.
Let's start by saying that at the moment there is no evidence of its existence and it is unlikely that you will find any in the coming years. The graviton is to gravity what the photon is to the electromagnetic force just as gravitational waves are the equivalent of light and since at this stage we have not yet directly located gravitational waves, we are very far from being able to locate their quantot if it exists. That is, in the meantime everything that is said about the existence or non-existence of gravitons can be based solely on theory without any visible hope of observation.
As for its theoretical existence or non-existence,
A few years ago I was bothered by the same question you raise:
If gravity is really not a force but an effect on space, why would it need a force-carrying particle? - After all, we know how it works at a distance - it distorts the space!
I turned to a person who understands a great deal about the subject and it turns out that you and I are not the first to think about it and the existence of the graviton is clearly not a necessary and direct result of the theory of relativity (not surprising, since the theory of relativity is a classical and not a quantum theory).
So why do Rabbis believe that Graviton exists?
The motivation for this comes from quantum field theory. Normal quantum field theory is done in Euclidean space. At a certain stage, attempts began to apply field theory in curved space, an idea whose most important result is Beckenstein Hawking radiation. The assumption was (as is assumed in relations) that the space is curved, but in a small enough area it is approximately flat and thus it is possible to learn from the "normal" quantum field theory about the behavior of the field theory in a curved space.
Later it turned out that such a treatment produces paradoxes, and from these they realized that the curvature of space cannot be smooth, but rather quantized on fairly small scales. The existence of a quantet in the curvature of space means a graviton - just as a change from a quantet in the strength of the electromagnetic field means a photon. So these paradoxes (the nature of which I do not know) show the existence of a need for the space quantot, that is, the existence of a graviton.
Note that the graviton will not in the least change the effects of general relativity since these live on large scales where you do not see the quantot curvature of space (just as light continues to behave as a wave if you do not look at experiments that force it to discover its quantum nature). What the existence of gravitons means is that in certain experiments, subtle enough, a quantum character to the curvature of space will be revealed. Meanwhile, we are very far from such experiments and, of course, many things are unknown about this because we do not have a complete quantum theory that unifies general relativity.
Joseph,
God forbid if you think I'm trying to knock you down or something like that, I just can't understand how time itself is supposed to be affected under entropic gravity and I was wondering if the developer of the theory addressed the issue.
Here and on other forums I wondered about the graviton (if it exists) and how it is supposed to work, how the graviton is supposed to affect time and whether its existence will disprove the curvature of space predicted by relativity (after all, why should space be curved if we have a boson that handles the issue)
Come on, good luck to entropic gravity
I just realized you're trying to see if I'm good at relationships in general. frame dragging If I'm not mistaken, this is the dragging of space by the moving masses. Dilution of time - this is the time that changes depending on the force of gravity, and a curved space is a space with an additional longitudinal axis on XYZ. I didn't study general relativity at university, but I taught myself from professional books and popular books. Many consider it amateurish but I take it seriously. I studied tensor algebra, Riemannian geometry, limited differential geometry, and limited Ricci flow.
My specialization is more quanta, electromagnetic radiation, the standard model, strings (whatever beyond) quantum bunches, quantum fields and field quantization.
A guy named Thanu Padmanabhan apparently showed a duality between entropic gravity and the curvature of space.
As for time changing depending on the speed of the reference system, I don't understand that.
I agree with you that the unification between general relativity and entropic gravity is not over - maybe it has just begun.
The work won the 2009 or 2010 Spinoza Prize, and a research grant of 2.5 million euros. I assume therefore that it was accepted by
The academic community is very serious. Such sums and prizes are not distributed for nothing.
Verlind's claim is that gravity is not a fundamental force but an entropic force. Therefore it does not exist in the dimensions of the weak, strong nuclear forces, but it does exist at the macroscopic level. So it can be reconciled with general relativity and does not contradict it.
Tried to unify general relativity with entropic gravity
http://en.wikipedia.org/wiki/Entropic_gravity
The current result (2014) is that general relativity can be derived from entropic entropy by theoretical extension but while
Imposing constraints of conservation of energy and conservation of momentum. In the absence of these constraints, there is a wider solution space than general relativity, as derived from entropic gravity. This result requires further research. If the only possible solution was general relativity - it would be nice.
The existence of additional solutions that are not observed in nature, or if less natural: the necessity to force the conservation of momentum and energy by accepting relativity
Looks imperfect. It's nice that you brought up this point, which is a major criticism of the theory.
Joseph,
Wait a second with the Nobel Prize...
The theory of relativity describes spatial curvature, time dilation and frame dragging as a result of gravity. If we leave for a moment the curvature of space, how does gravitational entropy explain the last two?
I went a bit far with the prediction about Verlind. This is my opinion. It is impossible to predict a Nobel Prize winner.
Excellent. This shows that indeed from 2010, when the theory of gravitation entropy was first proposed, that is, a serious theory with a strong theoretical basis, the infiltration into the mainstream in physics was very fast, four years, on the subject of no need for dark matter. Before 2010 there were other modified gravity theories but they didn't catch on. Professor Verlind - I bet - the Einstein of the beginning of the 21st century. Maybe I'm wrong. In physics, it takes 20 years to award a prize like the Nobel for theoretical physics. Even more.