About a hundred scientists from all over the world, including scientists from the Weizmann Institute of Science, inaugurated yesterday - in a tunnel under Mount Gran Sasso, in the chain of the Apennine mountains in Italy, the "One Ton Xenon" experiment, hoping to find a solution to the mystery of dark matter, which apparently makes up about 85% of all the matter in the universe
About a hundred scientists from all over the world, including scientists from the Weizmann Institute of Science, inaugurated yesterday - in a tunnel under Mount Gran Sasso, in the chain of the Apennine mountains in Italy, the "One Ton Xenon" experiment, hoping to find a solution to the mystery of dark matter, which apparently makes up about 85% of all the matter in the universe .
Dr. Ran Bodnik from the Weizmann Institute of Science, head of the group of institute scientists participating in the experiment: "The universe, for a reason that is not yet clear to us, 'behaves' as if it contains much more matter than the amount of matter we see in it. This is a sweeping phenomenon, which we notice, albeit in different forms, in the behavior of the entire universe, as well as in the movement of galaxy clusters, clouds of interstellar matter and individual galaxies."
The accepted method for calculating the mass of different parts of the universe is based on measuring the speed of the galaxies, stars and gas clouds included in it, and on measuring the trajectory in which they move. With this method of weighing, or calculation, results are obtained according to which all the galaxies, stars and gas we notice are only a small part of the "real story" of the matter in the universe. For example, if the galaxies contained only the material we see in them, the various celestial bodies contained in the galaxies would have to move away from each other and "break the partnership". In the past, it was believed that this occurrence was prevented thanks to the action of gravitational forces exerted by the components of the galaxies - the stars and the gas clouds themselves. That is, their own gravitational forces force them to stay together. But in the meantime it turned out that the material we see in galaxies is not enough to exert such strong gravitational forces. Why, then, don't the galaxies break up, and why don't the stars contained in them scatter all over the universe?
The absence of answers to these questions threatens our entire perception of the universe. Physicists seeking to resolve this discrepancy between the amount of visible matter in the universe, and the signs of the existence of more (or heavier) matter, have in the last two decades carried out several experiments with the aim of discovering dark matter, both directly - using special detectors built and placed on a sphere -Haaretz - and indirectly, through observations of various phenomena in space. So far, all these efforts have not been crowned with success.
To try and solve the mystery, more than a hundred scientists from ten countries joined together to establish and operate a unique experimental facility built especially for this purpose, in a tunnel dug under Mount Gran Sasso in the Apennine Mountains in Italy. The experiment is called "Xenon 1 Tonne" (Xenon 100 Tonne), after the noble gas found in the central tank of the detector designed to identify the dark matter particles that may reach the Earth. The new experiment, and at the heart of it the new detector, will enable a search with a sensitivity that is 10-30 times higher than the detectors that existed until now. The results it will provide in five days will be more than what previous experiments were able to achieve in XNUMX days to two years.
Scientists from the United States, Germany, Italy, Switzerland, Sweden, the Netherlands, France, Portugal, Israel and Abu Dhabi are participating in the experiment. The Weizmann Institute of Science financed the construction of the huge water tank, which contains three and a half tons of water, inside which is located the xenon tank and radiation detectors designed to filter cosmic particles. The height of the detector is equal to the height of a three-story building. It is installed in a tunnel under the mountain, to neutralize as much as possible the particles of cosmic radiation that might "confuse" it.
Dr. Ran Bodnik: "Actually, we currently do not have any knowledge about the nature and properties of the dark matter particles. However, we know for sure that they are not particles included in the 'Standard Model', the accepted theory of the visible and known structure of matter in the universe. There are many theories that try to predict the properties of these particles, and the experiments we are developing are able to discover these particles, which arise from many of these theories."
Scientists estimate that dark matter particles pass through each of us about millions of times per second, but almost always do not stop. The scientists hope that the new detector will detect the impact of several particles for a whole year on the detector.
20 תגובות
For those who asked about the force of gravity and brought the example of the ball in front of the marble regarding the force of gravity elbentzo I don't understand much about science but I just read and I believe you should check so if there is a sheet in the universe that catches all your balls a point for thought
one
Complicated things used to be simpler...
Thank you miracles!
Interesting, I don't remember that we were taught about this experiment... but I read a bit about it and saw videos on YouTube, really interesting.
one
We learned about this in high school... remember Rutherford's experiments shooting alpha particles at gold leaf. From the shape of the resulting scattering, he concluded that the atom has a small positive nucleus.
Physicists have known for 400 years that it is not possible to learn much only through the eyes 🙂
And another question regarding direct and indirect observations... a question that has always intrigued me, how do you actually know that the atom consists of a nucleus around which the electrons revolve? What experiment proved that this is the spatial structure of an atom? After all, no one has ever seen an atom with their own eyes directly, not even through a microscope as far as I know (they saw a round "bump" which is the atom, but not its internal structure) so how do you know what its structure is such a tiny thing if no one did not see ?
elbentzo,
Does modern physics know how to explain what actually causes gravity? Why is the earth attracted to the sun? Is "something" pushing it towards the sun? The explanation of "a massive body that shapes the space around it" is familiar to me, but it sounds very simplistic and incomprehensible to me. There is the example that they like to give of a heavy ball that is placed on a mattress and creates a "sink" and then if we put a small marble next to it it will roll in its direction, but what's funny about this example is that in the first place the force of gravity is needed for the marble to roll down into the socket... so I'm not sure that this is the best example .
Yehuda
I think you misunderstood me. I think that fitting a formula to measurements (and only to a part) does not explain anything. Darwin "changed the formula" of Lamarck, but he gave the change an explanation. If the genes had not been discovered until today, would that invalidate the theory of evolution?
And Yehuda - what do you do with the variety of additional evidence for dark matter? You sound to me a bit like a religious person who adapts reality to his views, instead of the other way around.
really?
How many times have you been provided with links to scientific papers that cite the positive evidence for dark matter? How many times have you refused to read the articles?
How many times has it been explained to you that no one has ever changed an observational data, but only changed the theoretical model to one that fits the measurements?
How many times has it been explained to you that dark matter has a thousand consequences beyond rotations in spiral galaxies, and that your revised formulas do not explain (and even contradict) all the other consequences (which of course the dark matter theory explains precisely)?
How many times has it been pointed out to you that you look at evidence selectively, and that your arguments are based on a book for high school students whose introduction says that it does not present the full picture?
How many times have they explained to you that there is no such thing as a "gravitational formula" for a hundred years? that it was replaced by Einstein in the theory of general relativity, and that if you want to change what you call the "gravitational formula" you have to change the whole theory (which, of course, is one of the most verified theories in scientific history)?
You're just proving yourself a liar...
To Albanzo - please don't call me a liar, of course there's no point in answering Mr. Albanzo, a scientist who was turned on by the name Yehuda.
And no one has ever proven to me that my claims about dark mass are baseless.
For a very small physicist. I enjoyed reading your comment.
Nissim I tried to change Newton's formula and the only change is going to another solution that does not refer to gravity.
a very small physicist,
I feel you are doing Dark Matter a bit of an injustice in your comparisons and examples. For example, all failures of theoretical predictions (proposed before experimental evidence) were failures because they were completely obscured by experiment. For example, in every introductory course to private relativity, you learn how to see in an experiment that there is no site. Dark matter not only does not contradict any experimental evidence, but also has predictions that match. Its problem (and it should not be underestimated) is that we do not have microscopic information about the particles that make it up.
The sentence "It is not possible to foresee any phenomenon that is a "direct" cause" is also misleading. There is observational evidence of dark matter (the most famous is the bullet cluster). Also, the reference to the word "directly" is itself somewhat misleading, because for many years in physics we have not relied only on direct phenomena. For example, no one has ever seen an electron. So it is true that we have more information about the microscopic properties of the electron than about those of dark matter, but one should be careful with the demand for direct evidence. Besides, it is not clear exactly what is meant by "directly causing". For example, it directly causes certain structures in the power spectrum of the background radiation - there is a theoretical development for this and the prediction correlates with the measurements. Is it direct or indirect in your eyes?
Finally, comparing dark matter to turtles with elephants, etc. - a religious idea that not only has no scientific basis but is itself anti-scientific - is a bit outrageous. As mentioned, dark matter is still mysterious, there is still much to explore and discover about it, and there is still a non-zero probability that we will discover an alternative explanation for gravity that does not include it at all (just as we may discover tomorrow that the theory of relativity is wrong), but it is a scientific idea, based on observations, that produces predictions that fit for observations and explains all the phenomena in the field.
Good,
There is no point in talking with Yehuda, so just for the benefit of the other commenters we will mention that he lies with a determined forehead. There is no point in listening to him, because he is saying wrong things (which he has been proven to be wrong), but he refuses to change the permanent post he pastes every time he sees the words "dark matter". Needless to say, no one ever changed measurements (all that was changed was the physical model from one that was hidden by the measurements, to one that matches them exactly and even produces new predictions that have been adjusted countless times - in other words, science).
Changing Newton's formula is very nice, but today's cosmological theories are built around general relativity. Einstein and his successors have already demonstrated their willingness to add and subtract terms from the formulas according to observations, and indeed a constant was added to describe the contribution of dark energy to the expansion of the universe. Apparently it doesn't work as far as dark mass is concerned.
June - As far as I understood, it is possible to measure "dark matter" only according to its gravitational effect on other particles. I didn't really understand how it works in the detector (maybe tiny changes in the direction/velocity of electrons of known origin), but I guess if you invest so much money and effort, scientists have a good reason to assume it works 🙂
Yehuda
A formula is not a physical explanation. If you change Newton's formula, you have explained nothing.
And to say "the dark matter was not found" is to say nonsense, forgive me. We don't know everything about him, but there is enough evidence of his existence.
to "a very small physicist"
My intuition tells me that you are not really a very small physicist
Maybe not very big either, but definitely a professional and well-respected physicist in his field
Said at the level of a professor from the academy
Although as the well-worn saying "you did not discover the theory of relativity",
But you definitely discovered important and meaningful things
I even guess, between myself, who you are
I didn't understand from the article - how is this detector supposed to detect the dark matter????
If we don't know anything about it - and it has no interaction with the materials we know - then why would it be different in this material - what would make them say that dark matter hit the container????
"The dark matter, which apparently makes up about 85% of all the matter in the universe" I think that the dark matter is only about a quarter of the mass/energy of the universe. Most of the rest is dark energy and only about five percent is "normal" observable matter!
Pretty
. When the gravitation data measured in the field do not match what is obtained from the Newton-Einstein gravitation formula, one simple thing must be done and that is to throw away the formula and look for another one. There is no reason in the world to change the measured data and add (dark) matter to them and when that doesn't work out then also dark energy. The main thing is that the measured results conform to the "holy" gravitation formula.. There is no reason in the world that a law proven at distances of a thousand light years (in the solar system) should exist Even at distances of millions and billions of light years! I know it's mainly a psychological matter, it's hard to say goodbye to the formula, after all we were born with it and the story of the apple that fell on Newton's head is unforgettable, but for eighty years we've been looking for the two particles of the dark-illusory mass without much success! So you have to decide that searching is enough. Bye bye the gravitation formula, the vast universe at great cosmological distances works differently.
Please respond gently, please.
The story of dark matter is fascinating not only from a scientific point of view but also (and perhaps to no less extent) from a philosophical point of view. What do we have here? Physical and cosmological theories that get along perfectly with each other, but together produce an illogical result of the movement of the heavenly bodies. It must be remembered that we do not directly measure any of the data of the celestial bodies, their weight and movement, but rely on rich theories that help us translate what we see through the telescopes into a complete story. There is no other way, everyone is doing science.
In order for the data to "correct" it was proposed to add "dark matter" in huge quantities, which surrounds us without us being able to feel it until now. Such theoretical approaches, which hypothesized the existence of materials and objects prior to discoveries, produced wonderful results in the past, such as predicting the existence of subatomic particles, which were eventually found and shook the entire theory. They also produced glorious failures, such as aether, that Greek celestial substance mobilized to fill space and allow the movement of electromagnetic waves. Except for the word "airwaves" to denote radio broadcasts, nothing remains of it; And in front of him is the "phlogiston", the same substance that supposedly creates the fire when it flows through the material.
There have been cases where the hypotheses put forward have demonstrated a good match between the theoretical prediction and the findings that can be discovered. In contrast, there were cases where the discrepancy led to a total rejection of the theory.
What will happen to the cosmological theory? Will findings be found that will cause the dark matter hypothesis to be adopted and allow the theory to be maintained, or as we deepen the research on dark matter and nothing is found, the entire theory will be rejected? In the meantime, clinging to the dark matter theory is fascinating. A great many physicists and cosmologists believe in its existence, it organizes the theories that without it would collapse, but it is not possible to witness any phenomenon that it causes "directly".
But in the future, what will the scientists choose to keep - the beautiful theory for the defense of which secret dark matter is being mobilized, or sticking to the findings that show there is no such matter, even if it means rejecting the theory?
Meanwhile, the dark matter resembles that turtle swimming in the ocean, on which three elephants stand, which once held the earth lest it fall. Even this turtle has not been found to this day, and we still live well on stable ground (which Copernicus taught us is moving at enormous speed through space).