Dark matter/Dark Energy

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Profile Bob DeWoody
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Message 1833195 - Posted: 29 Nov 2016, 19:35:39 UTC - in response to Message 1833123.  

And what proof do you have that these things even exist?
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.
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Message 1833396 - Posted: 30 Nov 2016, 21:25:35 UTC

There are many candidate theories to what dark matter is.
These are among them but now it's looks like it has boiled to only two.
Anti matter. Not.
Neutrinos. Not.
Sterile neutrinos. Could be.
MACHOs. Not. But white dwarfs could be about 15% of the dark matter.
Primordinal black holes. Possible.
WIMPZILLAs. Not.
WIMPs. More possible.
Axions. More possible.

http://www.svtplay.se/video/11165417/vetenskapsstudion/vetenskapsstudion-sasong-1-avsnitt-8:05:40:00
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Message 1833494 - Posted: 1 Dec 2016, 17:18:41 UTC - in response to Message 1833195.  
Last modified: 1 Dec 2016, 17:39:16 UTC

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.

and this would also explain "the force"
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Message 1833502 - Posted: 1 Dec 2016, 17:46:28 UTC - in response to Message 1833494.  

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.
and this would also explain "the force"

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 .
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Message 1838055 - Posted: 27 Dec 2016, 1:34:26 UTC

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.

Allan Rubin said she died on Sunday of natural causes, AP reported. She was living in Princeton, New Jersey.

Her studies earned her numerous honours, including being the second female astronomer to be elected to the US National Academy of Sciences.

But many questioned why she was never awarded a Nobel Prize

Name change to reflect my BOINC ID number
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Message 1838115 - Posted: 27 Dec 2016, 13:34:31 UTC - in response to Message 1838055.  
Last modified: 27 Dec 2016, 13:35:31 UTC

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
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Message 1838119 - Posted: 27 Dec 2016, 14:19:25 UTC - in response to Message 1838115.  

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.
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Message 1838433 - Posted: 29 Dec 2016, 5:06:58 UTC

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.

The finding could explain one of the biggest mysteries in physics - why our Universe appears to function in a slightly different way than it did in the years just after the Big Bang, and it could also shed insight into how it might continue to evolve in future.

"The discrepancy between the cosmological parameters in the modern Universe and the Universe shortly after the Big Bang can be explained by the fact that the proportion of dark matter has decreased," said co-author Igor Tkachev, from the Institute for Nuclear Research in Moscow.

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Message 1838456 - Posted: 29 Dec 2016, 7:11:39 UTC
Last modified: 29 Dec 2016, 7:21:17 UTC

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:)
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Profile William Rothamel
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Message 1838519 - Posted: 29 Dec 2016, 14:16:19 UTC

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 ?
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Message 1845714 - Posted: 1 Feb 2017, 4:29:02 UTC

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.
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Message 1845721 - Posted: 1 Feb 2017, 6:06:59 UTC - in response to Message 1845714.  

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.

Perhaps a helicopter view of that could be that they are all barking up the wrong tree. (or just barking ....)

We are told that if anti-matter collides with matter then they annihilate each other. If the universe consists of 86% antimatter, then in theory the universe shouldn't exist at all should it? It should have cancelled itself out billons of years ago.
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Message 1845740 - Posted: 1 Feb 2017, 10:00:34 UTC - in response to Message 1845721.  

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
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Message 1845913 - Posted: 2 Feb 2017, 10:14:01 UTC - in response to Message 1845740.  

You are correct Tullio, I mis-read that, it 86% dark matter not antimatter. Must pay more attention. Ooops sorry :-(
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Message 1845936 - Posted: 2 Feb 2017, 14:51:14 UTC - in response to Message 1845913.  

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
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Message 1850155 - Posted: 20 Feb 2017, 9:08:33 UTC

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
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Message 1850467 - Posted: 22 Feb 2017, 7:13:45 UTC

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
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Message 1859701 - Posted: 5 Apr 2017, 22:10:13 UTC

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.

But that’s a very big if.

Cheers.
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Message 1861386 - Posted: 14 Apr 2017, 5:56:44 UTC - in response to Message 1859701.  



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.
ET Phone Home
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Message 1862502 - Posted: 20 Apr 2017, 15:12:06 UTC
Last modified: 20 Apr 2017, 15:12:54 UTC

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
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Message boards : Science (non-SETI) : Dark matter/Dark Energy


 
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