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Dark matter/Dark Energy
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Author | Message |
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janneseti Send message Joined: 14 Oct 09 Posts: 14106 Credit: 655,366 RAC: 0 |
plato (maybe aristotle) mentioned atoms thousands of years ago and we were not able to measure them until the past century. some other greeks had the idea that the universe is continuous (superstring theory). perhaps they were both correct: the universe itself has mass, the difference lies in density. sometimes you just have a hunch. The only force dark matter interact with is the weak nuclear force. That's what all experiments are trying to detect when a dark matter particle hits an atom. Billions of particles of dark matter pass through our bodies every second, and about once a month collide a particle with a nucleus in us, but since the collision does not emit any light, it is about very weak forces that do not cause any harm, says Katherine Freese . |
W-K 666 Send message Joined: 18 May 99 Posts: 19443 Credit: 40,757,560 RAC: 67 |
Vera Rubin, pioneering astronomer, dies at 88 Astronomer Vera Rubin, whose pioneering work on galaxy rotation rates led to the theory of dark matter, has died at the age of 88, her son says. |
tullio Send message Joined: 9 Apr 04 Posts: 8797 Credit: 2,930,782 RAC: 1 |
Nobel prizes are not awarded for astronomy, geology, climate science and other important subjects such as mathematics. They should be reformed, but Yuri Milner is covering a good deal of sciences neglected by the Nobel Foundation. Tullio |
janneseti Send message Joined: 14 Oct 09 Posts: 14106 Credit: 655,366 RAC: 0 |
Nobel prizes are not awarded to every field of science. Only in physics, medicine and chemistry and who shall have made the most important discovery or invention and have conferred the greatest benefit to mankind. Nobel's will. The whole of my remaining realizable estate shall be dealt with in the following way: the capital, invested in safe securities by my executors, shall constitute a fund, the interest on which shall be annually distributed in the form of prizes to those who, during the preceding year, shall have conferred the greatest benefit to mankind. The said interest shall be divided into five equal parts, which shall be apportioned as follows: one part to the person who shall have made the most important discovery or invention within the field of physics; one part to the person who shall have made the most important chemical discovery or improvement; one part to the person who shall have made the most important discovery within the domain of physiology or medicine; one part to the person who shall have produced in the field of literature the most outstanding work in an ideal direction; and one part to the person who shall have done the most or the best work for fraternity between nations, for the abolition or reduction of standing armies and for the holding and promotion of peace congresses. |
Gary Charpentier Send message Joined: 25 Dec 00 Posts: 31066 Credit: 53,134,872 RAC: 32 |
http://www.sciencealert.com/the-universe-is-losing-dark-matter-and-researchers-have-just-measure-how-much Researchers from Russia have, for the first time, been able to measure the amount of dark matter the Universe has lost since the Big Bang some 13.7 billion years ago, and calculate that as much as 5 percent of dark matter could have deteriorated. |
janneseti Send message Joined: 14 Oct 09 Posts: 14106 Credit: 655,366 RAC: 0 |
Mind boggling. Ordinary matter deteriorate MUCH slower. A photon has about a billion billion years to deteriorate. Yes, roughly a billion times longer that our universe have existed. Well scientists like these findings:) |
William Rothamel Send message Joined: 25 Oct 06 Posts: 3756 Credit: 1,999,735 RAC: 4 |
Has the proportion of the putative dark matter "decreased" or has it simply expanded out further and thereby weakened it's gravitational effect. as the Universe and it's galaxies create more space ? |
Bob DeWoody Send message Joined: 9 May 10 Posts: 3387 Credit: 4,182,900 RAC: 10 |
New programming in "How the Universe Works" was aired Tuesday evening regarding Dark Matter. It was basically an hour of speculation concerning the nature of and possible effects of whatever it is. No new revelations of discoveries. I think it really bugs the scientific world that they have almost no clue about the nature of what they believe constitutes 86% of the matter in the universe. Bob DeWoody My motto: Never do today what you can put off until tomorrow as it may not be required. This no longer applies in light of current events. |
tullio Send message Joined: 9 Apr 04 Posts: 8797 Credit: 2,930,782 RAC: 1 |
Dark matter is not antimatter. Why the Universe is made up of a larger matter part and very little antimatter is one of the major astrophysics questions. Tullio |
tullio Send message Joined: 9 Apr 04 Posts: 8797 Credit: 2,930,782 RAC: 1 |
I am taking an online course by the Diderot University of Paris on Gravitation. Maybe I shall learn something more on dark matter. I have read the obituary of Vera Rubin on "Nature" magazine, who was the main proponent of dark matter with her studies on the rotation of galaxies. Bu Fritz Zwicky had already spoken of "missing mass" in 1933. Tullio |
tullio Send message Joined: 9 Apr 04 Posts: 8797 Credit: 2,930,782 RAC: 1 |
The Diderot University online course speaks of Fritz Zwicky as the father of the dark matter idea. He called it "missing mass" in 1933. Tullio |
tullio Send message Joined: 9 Apr 04 Posts: 8797 Credit: 2,930,782 RAC: 1 |
The Fermi orbiting gamma-ray telescope has discovered a strong gamma-ray emission from the center of M31, the Andromeda galaxy. NASA says it might be a sign of interacting dark matter or a number of gamma-ray pulsars like the ones which are discovered by the Einstein@home project with both CPU tasks and GPU tasks, which give a good amount of credits. My Einstein RAC has reached 20k, a figure never reached in any project so far. Tullio |
Wiggo Send message Joined: 24 Jan 00 Posts: 37119 Credit: 261,360,520 RAC: 489 |
New study suggests the expansion of the universe is not driven by dark energy. As Science Magazine points out, if this is the case then one of the biggest mysteries in physics could be explained away with nothing other than Albert Einstein’s familiar general theory of relativity. Cheers. |
Lynn Send message Joined: 20 Nov 00 Posts: 14162 Credit: 79,603,650 RAC: 123 |
http://www.wired.co.uk/article/dark-matter-bridge A dark matter 'bridge' holding galaxies together has been captured for the first time Researchers at the University of Waterloo used a technique known as weak gravitational lensing to create a composite image of the bridge. Gravitational lensing is an effect that causes the images of distant galaxies to warp slightly under the influence of an unseen mass, such as a planet, a black hole, or in this case, dark matter. They found the damn stuff. |
tullio Send message Joined: 9 Apr 04 Posts: 8797 Credit: 2,930,782 RAC: 1 |
I am suggesting everybody to read the May issue of CERN Courier, already on line, on the subject of Dark Matter. There are three articles covering its history and developments, including the fact that dark matter seems less abundant in old galaxies basing on the rotational curves of spiral galaxies, which were the main argument Vera Rubin had used to establish the presence of Dark Matter. Tullio |
Gary Charpentier Send message Joined: 25 Dec 00 Posts: 31066 Credit: 53,134,872 RAC: 32 |
I am suggesting everybody to read the May issue of CERN Courier, already on line, on the subject of Dark Matter. There are three articles covering its history and developments, including the fact that dark matter seems less abundant in old galaxies basing on the rotational curves of spiral galaxies, which were the main argument Vera Rubin had used to establish the presence of Dark Matter.Interesting. So could dark matter be being emitted by fusion? So that as a galaxy ages normal matter is converted into dark? Or is there a time factor in the equations of gravity? |
tullio Send message Joined: 9 Apr 04 Posts: 8797 Credit: 2,930,782 RAC: 1 |
On the same issue there is an interview with Erik Verlinde, who says that General Relativity is wrong and propose an entirely new theory of gravitation, which could explain both dark matter and dark energy. Time will tell. Tullio |
janneseti Send message Joined: 14 Oct 09 Posts: 14106 Credit: 655,366 RAC: 0 |
On the same issue there is an interview with Erik Verlinde, who says that General Relativity is wrong and propose an entirely new theory of gravitation, which could explain both dark matter and dark energy. Time will tell. Emergent gravity as it called. https://astronomynow.com/2016/11/08/new-theory-of-gravity-might-explain-dark-matter/ According to Verlinde, gravity is not a fundamental force of nature, but an emergent phenomenon. In the same way that temperature arises from the movement of microscopic particles, gravity emerges from the changes of fundamental bits of information, stored in the very structure of spacetime. Short. Gravity is just an illusion:) |
janneseti Send message Joined: 14 Oct 09 Posts: 14106 Credit: 655,366 RAC: 0 |
Short. Gravity is just an illusion:) Hehe:) And in the morning and getting off your bed is also difficult. |
janneseti Send message Joined: 14 Oct 09 Posts: 14106 Credit: 655,366 RAC: 0 |
Actually I get out of my bed not off it, and on the right side :-) Seems like I'm not the only one that do the same mistake. https://forum.wordreference.com/threads/get-off-my-bed-vs-get-out-of-my-bed.2318156/ |
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