Dark matter/Dark Energy

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Message 1440086 - Posted: 8 Nov 2013, 2:13:52 UTC - in response to Message 1440007.  

Then the question is, where is the universe expanding to. Is it going to go out with a Wimper, or a Bang??

All a question of Entropy and Information?


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Message 1441263 - Posted: 11 Nov 2013, 16:12:54 UTC

S=klnW is written on Ludvig Boltzmann's grave in Wien, so I was told. He killed himself in Duino, where Rainer Maria Rilke had written his "Elegies". Probably he felt misunderstood by his peers.
Now they say that entropy is proportional to the area of the surface of the events horizon surrounding a black hole. I wonder what Boltzmann would think of this.
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Message 1441287 - Posted: 11 Nov 2013, 18:00:04 UTC - in response to Message 1441263.  

S=klnW is written on Ludvig Boltzmann's grave in Wien, so I was told. He killed himself in Duino, where Rainer Maria Rilke had written his "Elegies". Probably he felt misunderstood by his peers.
Now they say that entropy is proportional to the area of the surface of the events horizon surrounding a black hole. I wonder what Boltzmann would think of this.
Tullio

A sad end on all counts.

The event horizon proportionality is also called the 'holographic limit to information'. That suggests that the Canadian quantum computer is an impossibility if it is supposed to be truly quantum... However, can they dodge the limits by claiming/ operating some form of fast superconductivity simulated annealing?...


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Message 1441543 - Posted: 12 Nov 2013, 11:56:31 UTC - in response to Message 1441287.  
Last modified: 12 Nov 2013, 11:58:07 UTC

I just don't know enough to answer your question. But a friend of mine and former colleague at Elsag ,Genoa, Giuseppe Castagnoli, and prof. Mario Rasetti of Torino Polytechnic University have developed a method of "simulated annealing" already in the Nineties. An article on this subject was published jointly by Castagnoli and me in the Italian edition of MIT Technology Review in December 1996. Its title was 'Le altre dimensioni del problema" and it has a bibliography. I know that Castagnoli, now retired from Elsag, as I am, is still working on quantum computers.
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Message 1448244 - Posted: 29 Nov 2013, 7:34:52 UTC - in response to Message 1441543.  

How do you measure something that is invisible?



Can you match each galaxy in the top row with its warped counterpart in the bottom row? For example, is the warped version of galaxy A in box D, E, or F?

How do you measure something that is invisible? It's a challenging task, but astronomers have made progress on one front: the study of dark matter and dark energy, two of the most mysterious substances in our cosmos. Dark matter is intermixed with normal matter, but it gives off no light, making it impossible to see. Dark energy is even more slippery, yet scientists think it works against gravity to pull our universe apart at the seams.

http://www.nasa.gov/jpl/galaxy-20131126.html#.UphB8yfTDSc
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Message 1448245 - Posted: 29 Nov 2013, 7:47:15 UTC - in response to Message 1448244.  

Those are 'too easy' by just looking for the mix of colours. Can not instruments do the same by looking at the spectrum counts?...


So... Is this a "Galaxy Zoo" follow-up to try to classify Einstein rings and other gravitational lensing?


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Message 1453541 - Posted: 13 Dec 2013, 14:28:52 UTC

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Message 1453552 - Posted: 13 Dec 2013, 14:54:43 UTC
Last modified: 13 Dec 2013, 14:55:25 UTC

The LUX experiment (Large Underground Xenon) has found no trace of dark matter WIMPs (Weakly Interacting Massive Particles). So the question is still open.
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Message 1453561 - Posted: 13 Dec 2013, 15:50:24 UTC
Last modified: 13 Dec 2013, 15:51:33 UTC

According to this article, you are right Tullio.

http://arstechnica.com/science/2013/10/new-lux-experiment-no-dark-matter-in-this-corner/

Of course, this result isn't a definitive statement on the existence of dark matter, but it does put stronger constraints on what its identity could be. Dark matter could still lurk at lower mass ranges, or it could be non-WIMP in nature. The latter possibility includes the disturbing prospect that dark matter doesn't interact directly with normal matter at all, except through gravity, dooming every current detection scheme to failure.


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Message 1453585 - Posted: 13 Dec 2013, 18:08:17 UTC - in response to Message 1453561.  

Julie, I stick to experimental facts. I am a physicist, even if retired, and I am against speculations.
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Message 1453587 - Posted: 13 Dec 2013, 18:20:51 UTC
Last modified: 13 Dec 2013, 18:21:56 UTC

I understand quite well Tullio
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Message 1453608 - Posted: 13 Dec 2013, 19:48:15 UTC - in response to Message 1453585.  

Julie, I stick to experimental facts. I am a physicist, even if retired, and I am against speculations.
Tullio



I had a feeling about you, Tullio. Good for you :-)
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Message 1457918 - Posted: 27 Dec 2013, 11:56:11 UTC

Two thousand years ago, a Roman vessel with ingots of lead extracted from the Sierra of Cartagena sank across the waters from the coast of Sardinia. Since 2011, more than a hundred of these ingots have been used to build the 'Cryogenic Underground Observatory for Rare Events' (CUORE), an advanced detector of neutrinos- almost weightless subatomic particles- at the Gran Sasso National Laboratory in Italy.


Use of Roman ingots in 'dark matter and neutrinos study' sparks controversy
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Message 1457946 - Posted: 27 Dec 2013, 15:33:48 UTC - in response to Message 1457918.  

Some say that the decline of the Roman Empire was also due to lead poisoning because lead was used in the Roman Aqueducts, some of which are still standing, although no longer used to bring water to people.
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Message 1458010 - Posted: 27 Dec 2013, 20:01:30 UTC - in response to Message 1457946.  

The lead that caused the problems was used as makeup


In a rich man's house there is no place to spit but his face.
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Message 1458142 - Posted: 28 Dec 2013, 8:44:20 UTC

There was also a lot of lead in the drinking cups and containers their wine was stored in. I saw also that lead made the wine taste sweeter. Whatever this has to do with dark matter or dark energy is beyond me.
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Message 1458176 - Posted: 28 Dec 2013, 11:40:00 UTC - in response to Message 1458142.  

Even neutrinos have nothing to to with dark matter,leave alone dark energy.Lead is used to shield the neutrino detectors from radioactivity coming from the rocks, since neutrino detectors are situated underground or underwater as in ICECUBE.
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Message 1461732 - Posted: 8 Jan 2014, 7:50:26 UTC

Dark Matter Search Considers Exotic Possibilities:


http://www.scientificamerican.com/article.cfm?id=dark-matter-exotic-possibilities&utm_content=buffer7d357&utm_source=buffer&utm_medium=facebook&utm_campaign=Buffer

Physicists still have no proof that dark matter exists at all, but the evidence for it is substantial. The movements of stars and galaxies can apparently be explained only if there is much more gravitating matter in the universe than the visible stuff of atoms and molecules. Attempts to correct the discrepancy by rewriting the rules of gravity in Einstein's general theory of relativity have repeatedly failed.

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Message 1461951 - Posted: 8 Jan 2014, 22:50:31 UTC - in response to Message 1461732.  

Dark Matter Search Considers Exotic Possibilities:


http://www.scientificamerican.com/article.cfm?id=dark-matter-exotic-possibilities&utm_content=buffer7d357&utm_source=buffer&utm_medium=facebook&utm_campaign=Buffer

Physicists still have no proof that dark matter exists at all, but the evidence for it is substantial. The movements of stars and galaxies can apparently be explained only if there is much more gravitating matter in the universe than the visible stuff of atoms and molecules. Attempts to correct the discrepancy by rewriting the rules of gravity in Einstein's general theory of relativity have repeatedly failed.


Thanks Julie.

Just because they can't see it doesn't mean it isn't there.
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Message 1461953 - Posted: 8 Jan 2014, 22:55:01 UTC - in response to Message 1461951.  

Dark Matter Search Considers Exotic Possibilities:


http://www.scientificamerican.com/article.cfm?id=dark-matter-exotic-possibilities&utm_content=buffer7d357&utm_source=buffer&utm_medium=facebook&utm_campaign=Buffer

Physicists still have no proof that dark matter exists at all, but the evidence for it is substantial. The movements of stars and galaxies can apparently be explained only if there is much more gravitating matter in the universe than the visible stuff of atoms and molecules. Attempts to correct the discrepancy by rewriting the rules of gravity in Einstein's general theory of relativity have repeatedly failed.


Thanks Julie.

Just because they can't see it doesn't mean it isn't there.



I know Lynn, we're unraveling bits by bits...
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Message boards : Science (non-SETI) : Dark matter/Dark Energy


 
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