Science 'finds' the missing 90% of the Universe

[JackLuis]

Whew, for a while I thought it was gone!

"This is fascinating news: 90% of the distant Universe was thought to be missing, but it was recently found. And what’s weird is, it was found to be in the red. Quite literally."

 

[Xelebes]

Someone beat you to the punch.

 

[Starscream_UK]

I thought it was in the back of my sofa - along with an old chequebook, a whistle and my cat's favourite toy...

 

[JackLuis]

Someone beat you to the punch.

Oops.

 

[dr_mabeuse]

There's something wrong here. I was going to say something when I saw 3113's thread on the same topic but I didn't think it was really worth getting into a possible row about, but apparently this discovery is being trumpeted as something really significant, and as far as I can tell, it really isn't. I think these scientists are maybe trying to drum up publicity for "proving" something that was actually known a long time ago, theoretically at least. All they did was demonstrate something everyone already knew.

The original question, asked maybe a hundred years ago, is: why isn't the night sky white instead of black? By 1910 we knew that space was packed with stars, that everywhere you looked with a telescope there were stars and galaxies streaming with visible light. So why didn't this plenitude of stars render the sky white at night?

Clearly something out there was absorbing this light, and it wasn't long before these absorbers were found: great, huge clouds of hydrogen gas and "dust" (frozen water vapor and other crap). They absorbed something like 99.9999% of the starlight shining upon them in the visible spectrum.

So no one was really surprised that this stellar hydrogen couldn't be observed. We knew it was there. We just couldn't see it through the interstellar smog. I don't think anyone gave it much thought or bothered to look for it.

As far as I can tell, all these guys did in this current study did was prove that what everyone knew was there was, in fact, indeed there. That's nice to know, of course, but I really don't think it's the earth-shaking discovery the press is making it out to be. It's kind of like proving that, yes, it's wet at the bottom of the ocean.

 

[voluptuary_manque]

Well, the press tends to be scientifically illiterate, after all.

 

[Zeb_Carter]

There's something wrong here. I was going to say something when I saw 3113's thread on the same topic but I didn't think it was really worth getting into a possible row about, but apparently this discovery is being trumpeted as something really significant, and as far as I can tell, it really isn't. I think these scientists are maybe trying to drum up publicity for "proving" something that was actually known a long time ago, theoretically at least. All they did was demonstrate something everyone already knew.

The original question, asked maybe a hundred years ago, is: why isn't the night sky white instead of black? By 1910 we knew that space was packed with stars, that everywhere you looked with a telescope there were stars and galaxies streaming with visible light. So why didn't this plenitude of stars render the sky white at night?

Clearly something out there was absorbing this light, and it wasn't long before these absorbers were found: great, huge clouds of hydrogen gas and "dust" (frozen water vapor and other crap). They absorbed something like 99.9999% of the starlight shining upon them in the visible spectrum.

So no one was really surprised that this stellar hydrogen couldn't be observed. We knew it was there. We just couldn't see it through the interstellar smog. I don't think anyone gave it much thought or bothered to look for it.

As far as I can tell, all these guys did in this current study did was prove that what everyone knew was there was, in fact, indeed there. That's nice to know, of course, but I really don't think it's the earth-shaking discovery the press is making it out to be. It's kind of like proving that, yes, it's wet at the bottom of the ocean.

That may or may not be a true statement. Yes it is wet, except in some places it's actually wetter(?). There are places at the bottom of the ocean where denser seawater has collected in under water lakes. Pictures show what looks to be beaches and shoals as the submersible flew over the calm lake waters. It was magical. I saw it on the Discovery channel sometime ago.

 

[JackLuis]

I thought they had discovered Dark Matter, but then I read the article.

Still I thought it interesting.

 

[Verdad]

I thought they had discovered Dark Matter, but then I read the article.

They had discovered dark matter a few years ago. That is, the strongest piece of evidence to date to support it, but there are alternative explanations for that too. I don't know if there's been anything more recent, though.

 

[JAMESBJOHNSON]

The real puzzle is white flight from Africa.

The other day I was reading that something like 4 species of humans originated in Africa and all of them left. I wonder if it wasnt white flight. Makes you wonder.

 

[stephen55]

Why is the sky dark at night?

The original question, asked maybe a hundred years ago, is: why isn't the night sky white instead of black? By 1910 we knew that space was packed with stars, that everywhere you looked with a telescope there were stars and galaxies streaming with visible light. So why didn't this plenitude of stars render the sky white at night?

This is actually a serious question and one which took a while to answer properly. The question is often posed as Olber's Paradox.

The paradox states that at any angle from the Earth the sight line will end at the surface of a star. To understand this we compare it to standing in a forest of white trees. If at any point the vision of the observer ended at the surface of a tree, wouldn't the observer only see white? This contradicts the darkness of the night sky and leads many to wonder why we do not see only light from stars in the night sky....The paradox is commonly attributed to the German amateur astronomer Heinrich Wilhelm Olbers, who indeed described it in 1823... (from wikipedia)

I have a copy of Darkness at Night: A Riddle of the Universe by Edward Harrison. It's a great account of the puzzle which actually dates back to Democritus, the ancient Greek philosopher. Harrison says that the first person to come up with a proper explanation was William Thomson, 1st Baron Kelvin (or Lord Kelvin) in 1901. But the really fascinating part of the story is that, of all people, Edgar Allen Poe first came up with the basic idea in his essay, Eureka: A Prose Poem, an essay written in 1848, which included a cosmological theory that presaged the big bang theory by 80 years. Poe, besides being a writer of the macabre and mystery, was for a while an amateur scientist of reasonable repute, at least amongst malacologists (those who study snails).

As for the answer to Olber's paradox...it's in the stars.

 

[LaRocha]

The assumption was that stars shine eternally in a static universe, pretty much up until Arthur Eddington, Lemaitre, and Hubble in the 1920s.

 

[JAMESBJOHNSON]

Youre forced to wonder how much of this crap is nonsense and magical thinking guaranteed to keep these pirates in business....like global warming did. Bet the farm that someone discovers the end of the world a billion light years away, energizing Al Gore anew.

 

[LaRocha]

The universe is a dusty asshole.

 

[stephen55]

The universe is a dusty asshole.

As much as it pains me to admit it, LaRocha is close to the truth. Who would have thought?

 

[Handley_Page]

I assumed that an "asshole" was the exhaust" of some thing.

 

[JackLuis]

They had discovered dark matter a few years ago. That is, the strongest piece of evidence to date to support it, but there are alternative explanations for that too. I don't know if there's been anything more recent, though.

I'm not sure 'discovered is the correct term for the explanations of either attachment, but I think you for the info. I'm kind of a geek, but astronomy isn't something I am familiar with.

IN Avatar there was "Unobtainimum", sounds like they discovered "Unexplainimum" and and the nay sayers came up with, "But not if gravity works differently."

Much as we would like to think we "know" what is happening 3 Billion light years away, it happened 3 Billion years ago and the universe may have had different rules then?

What we think we know is probably less than half of what we need to know to explain the Universe. But that's MHO.

 

[voluptuary_manque]

"the Universe is not only stranger than we imagine, it's stranger than we can imagine."

 

[JackLuis]

As are Humans.

 

[stephen55]

Actually, only about 74% of the universe is missing (kind of).....

For reasons of his own, Einstein believed that the universe was static and unchanging. When he published his Theory of General Relativity in 1916 he hadn't considered that his own field equations, when applied to the universe as a whole, predicted that the universe could not be static, but must be either contracting or expanding. Alexander Friedmann, a Russian mathematician discovered the expanding-universe solution to the general relativity field equations in 1922. Einstein was at first skeptical and felt that Friedmann must have messed up his sums. However when he looked closer he realized that the guy was right. Still unable to accept an expanding universe, Einstein added a fudge factor (lambda: Λ) to his equations, a mathematical fiction that acted like a kind of anti-gravity, that would keep a static universe safe from expansion.

Then in 1929, the American astronomer Edwin Hubble showed that the universe was indeed expanding. Once convinced, Einstein dropped the fudge factor, calling it the greatest blunder of his life. (Actually, Einstein's greatest blunder was marrying Mileva Marić, but that's another story.)

Years later, when recalling his mistake over the fudge factor, Einstein said, "Two things are infinite, the universe and human stupidity and I'm not sure about the universe". Had he gone with what his own theory predicted, the later discovery of the expansion of the universe would have been his greatest triumph.

Fast forward to 1998. Two teams of astronomers showed that the universe was not only expanding, but that the expansion was accelerating. Instead of the expansion slowing down due to gravity, which was what everybody assumed was happening, the expansion was speeding up due to some kind of unknown factor (called dark energy, because it's weirder than weird) that acts like a kind of...wait for it...anti-gravity.

Poor Einstein. When he thought he was right, he was wrong. And after admitting he was wrong...now he's right (kind of). Dark energy makes up about 73-74% of the mass-energy of the universe. About 23% is dark matter. That leaves about 4% to make up all the matter we can actually see; stars, galaxies, intra and inter-galactic dust and gas (and us mere humans).

It's a bit humbling to realize that the stuff we're made of (normal matter) makes up less than 5% of what's out there.

 

[JAMESBJOHNSON]

We like to pretend that we're on top of things but only a century ago we believed space was filled with aether. We persist in believeing all kinds of shit that never was true.