90% of the Universe Found Hiding In Plain View

The Bad Astronomer writes "As much as 90% of previously hidden galaxies in the distant Universe have been found by astronomers using the Very Large Telescope in Chile. Previous surveys had looked for distant (10 billion light years away) galaxies by searching in a wavelength of ultraviolet light emitted by hydrogen atoms — distant young galaxies should be blasting out this light, but very few were detected. The problem is that the ultraviolet light never gets out of the galaxies, so we never see them. In this new study, astronomers searched a different wavelength emitted by hydrogen, and voila, ten times as many galaxies could be seen, meaning 90% of them had been missed before."

Comments

I Smell Another Apple Ad

[WrongSizeGlass]

90% of the Universe was discovered by thinking differently? Steve Jobs just felt a tingle somewhere.

Re:I Smell Another Apple Ad

[calibre-not-output]

A tingle? Steve Jobs just had to go get a change of pants.

Re:I Smell Another Apple Ad

[nacturation]

Shit, man... he had to change his liver!

Re:I Smell Another Apple Ad

[PopeRatzo]

And how do they know that they've found 90% of what was previously hidden?

Maybe there's more hidden than they thought was hidden.

Is the size of the universe so widely agreed-upon? Far be it from me to challenge a headline in Science, but I'm just a little curious about this assertion.

Re:I Smell Another Apple Ad

[AuMatar]

I hate that. Just to make that stop happening I now search for at least 5 minutes after I find something.

Re:I Smell Another Apple Ad

[SoVeryTired]

There's a big fat gap between what the calculations say the rate of galaxy formation should be, and what it is actually observed to be. This new observation accounts for 90% of that rate.

Re:I Smell Another Apple Ad

[b4dc0d3r]

A quote from the summary, which should appear directly above the comments in case you are not familiar with slashdot, is:

and voila, ten times as many galaxies could be seen

.

X is the previous amount, and 10x as the new amount of galaxies.

So simple math gives you X + YX = 10X
X(1+Y)=10x
(1+Y)=10
Y=9

So we see a 10-fold total galaxies, which is 9-fold improvement. Or to put it another way, the new 100% is 10 times the previous amount, which must have been 10%, leaving 90% more.

You're reading it as "90% of the universe found", from the headline, which is an attempt, although a poor one, at conveying the increase in observable galaxies. It is correct if you assume that we found 90% of the now-current estimate of the number of galaxies, in other words insert the word "known" in the title somewhere. Choosing not to even read the summary has left you understandably confused, and I'm glad that I was able to help. At the same time, I'm concerned that the other replies did not draw your attention to this. But I was able to post an accurate reply while maintaining an air of disdain and condescension, so that makes me feel good about myself. Thank you for affording me the opportunity, and welcome aboard.

Implications for dark matter estimates?

[Anonymous Coward]

Anyone got any idea how this impacts our estimates of dark matter?

Does dark matter disappear or do we still need some hiding to explain things?

Re:Implications for dark matter estimates?

[Mab_Mass]

Anyone got any idea how this impacts our estimates of dark matter?

From TFA:

"I'll note: this has nothing to do with dark matter. As it happens, 90% of the matter in the Universe is in a form that emits no light, but affects other matter through gravity. We know it exists ... locally, in nearby galaxies and clusters of galaxies, too. This new result doesn't affect that, since the now un-hidden galaxies are very far away, like many billions of light years away. They can't possibly affect nearby galaxies, so they don't account for dark matter."

Re:Implications for dark matter estimates?

[Jeff Satterley]

The Bad Astronomy post talks about dark matter: [Note: before you ask, this has nothing to do with dark matter. See below!] I’ll note: this has nothing to do with dark matter. As it happens, 90% of the matter in the Universe is in a form that emits no light, but affects other matter through gravity. We know it exists, and you can find out why here. We know it exists locally, in nearby galaxies and clusters of galaxies, too. This new result doesn’t affect that, since the now un-hidden galaxies are very far away, like many billions of light years away. They can’t possibly affect nearby galaxies, so they don’t account for dark matter.

Re:Implications for dark matter estimates?

[oldspewey]

More likely, a huge intellectual battle will break out among humankind, between the Dark Matter proponents and the Dark Matter deniers. Auditoriums full of angry people will hurl insults back and forth at each other, news stations will interview various scientific experts and political commentators in an effort to boost ratings, deniers will accuse the proponents of wanting to destroy the free-market universe and enslave humankind in some kind of subatomic socialism, while proponents will accuse the deniers of being selfish and greedy, willing to gamble the heat death of the entire universe just so they can run their colliders a little longer.

But that's just my prediction.

Re:Implications for dark matter estimates?

[spun]

Absolutely wrong. TFA even states this means nothing for dark matter, we knew that these galaxies were out there, we just hadn't spotted them yet. Besides, we've seen dark matter much closer to home. When galaxies collide, the gas pressure stops the regular matter, while the dark matter keeps moving along at the same speed. The dark matter has mass, so it creates a gravatic lens. We have seen these lenses, with no visible matter to create them, when galaxies collide.

Re:Implications for dark matter estimates?

[Mr Thinly Sliced]

Very nice. Thank you for explaining a little about what evidence we have for dark matter.

I knew about the fudge factor we needed to get the equations to work - I didn't know we have actually seen something like that.

Re:Implications for dark matter estimates?

[MozeeToby]

Dark matter isn't just matter that isn't lit up (that was one of the original theories, but has since fallen to the wayside), it is matter that is fundamentally different and doesn't appear to interact with regular matter at all, except gravitationally.

Re:Implications for dark matter estimates?

[Chris Burke]

it is matter that is fundamentally different and doesn't appear to interact with regular matter at all, except gravitationally.

More specifically, it doesn't appear to interact electromagnetically. Which just happens to exclude all of our direct detection methods (i.e. telescopes).

One candidate for dark matter is the neutralino, which is predicted by Supersymetric Theory and is basically a neutrino but heavier, and like a neutrino interacts through the Weak Interaction which allowed us to find neutrinos, and maybe even actual dark matter.

Re:Implications for dark matter estimates?

[Chris Burke]

I knew about the fudge factor we needed to get the equations to work - I didn't know we have actually seen something like that.

It was never a "fudge factor" to make the equation of gravity "work". It was a prediction of the already extremely well-working equation. Not "Oh noes gravity is broken, we need 'dark matter' to fix it." Rather "Huh, gravity implies there is a mass here that we can't see with our electromagnetic detection devices".

Think of it this way. You're walking around a room blindfolded with a cane that has a pressure sensor on the end that uses a voice synthesizer to tell you the readings. You notice that all along a large flat plane the pressure sensor detects pressure equal to that with which you push. Newton's 3rd Law tells you that for this to happen, something must be pushing back with equal force. Something like a wall.

Now, do you say that the wall is a fudge to make Newton's 3rd Law work?
Or do you say that Newton's 3rd Law implies that there is a wall there?

I mean you might as well say that the existence of the Sun is a fudge to make electromagnetic and gravitational equations work.

I'm not trying to rag on you or anything (I mean you said 'thank you' for evidence after all), just trying to clear up a misconception that I think has lead to a lot of unnecessary skepticism of dark matter.

I RTFA...

[Torrance]

...and this isn't the conclusion that I immediately jumped to - the discovery of dark matter. It's merely the discovery of the visible matter that they though should always be there.

Re:Dark stuff?

[Sponge Bath]

Does this account for any missing mass and/or dark matter?

FTFA: "...this has nothing to do with dark matter."

Scientists' pledge.

[Spazntwich]

Scientists on earth were said to be embarrassed by overlooking what had been there all along, and promised to never again take what they have for granted.

"It's like some crappy teen drama, and we just had to wait for the prom scene to realize how beautiful our soft-spoken nerdy friend is."

90% of the universe could not be reached for comment, as it decided itself too good for its unappreciative inattentive "friends" and went to the football players' afterparty.

Not "90% of the Universe"

[Neon Aardvark]

Merely 90% of the Visible Universe that we couldn't see before.

The Visible Universe probably constitutes a very small (perhaps even infinitesimally small) fraction of the actual physical Universe. The rest will, according to Relativity, always be hidden.

Next step: a better name

[spun]

The "Very Large Telescope?" Come on. We can do better than that. I suggest "Really Big Round Glass Thing for Seeing Further."

Re:Next step: a better name

[spun]

That's what Zoolander would name it.

I was thinking Leonard of Quirm.

Re:Next step: a better name

[mweather]

The next record-breaking one they're building is the Extremely Large Telescope. Seriously.

Re:Next step: a better name

[maxwell demon]

Actually it's the Overwhelmingly Large Telescope.

Re:Next step: a better name

[Spy der Mann]

Followed by the Ridiculously Large Telescope and the Ludicrously Large Telescope which, due to licensing and trademark issues, can ironically fit on your desk.

Spaceballs, the Telescope!

Re:Dark stuff?

[mcgrew]

The missing mass is comprised of all the socks that have slipped through the spacetime continuum when you put them in the washing machine. They emit no radiation, but exert gravity. It's especially grave when you can't find a matching pair.

Redshift?

[rsborg]

My first thought was, did they compensate for redshift? Apparently they did, the article didn't explain, but a commenter did:

30. TMB Says: March 24th, 2010 at 7:02 pm To everyone who's asking "why didn't they look at this before?" - it's a lot harder. In the rest frame, Lyman-alpha is in the far-UV and H-alpha (what physicists call Balmer-alpha) is in the optical. But out at these redshifts, Lyman-alpha is redshifted into the optical (which is easy to observe) and H-alpha is redshifted out into the infrared (which is harder to observe).

Re:Redshift?

[canadian_right]

Asking if professional astronomers took the red shift into account is like asking if some surgeons washed before performing surgery.

Re:Dark stuff?

[synaptik]

The socks don't escape through the washer. They escape through the dryer's lint trap. Eventually, after you've captured at least one socks-worth of lint, a sock somewhere in the world has to go "poof". (Note that it's not necessarily your sock, or your lint trap. It's a conservation-of-mass/quantum-lint-mechanics kind of thing.)

Re:Dark stuff?

[tool462]

That's why I never clean my lint trap. If I don't look, then my socks don't disappear!

I've Seen This Before

[Hoi Polloi]

"Hidden in plain view"? So what they are saying is that the universe exhibits the same behavior as my car keys.

Someone update the Drake Equation!

[scorp1us]

Since we just got a 10 fold increase in galaxies.

I think that moves us from 0.006 to 0.06, (plus one obviously)

Re:Dark stuff?

[Red Flayer]

Hogwash.

The lint that collects in your dryer is not made up of sock-matter. Dryer lint is mass created via the conversion of static electricity that accumulates while your dryer is running. If it weren't for the clever device to capture this energy and turn it into lint, running your dryer would cause an electrical discharge that makes a lightning bolt seem like a bee sting -- remember, E = mc^2.

The concundrum of missing socks remains unsolved, but the leading theory is that dark-matter socks spontaneously come into existence in your dryer, then meet your regular-matter socks, and puff out of existence with a corresponding release of a preposterous amount of energy (this, of course, is the source of energy that is converted into dryer-lint).

This theory is under fire, though, as a controlled study at the Institute for Laundering Science determined that socks sometimes disappear in the washer, not just the dryer -- explanation for what happens to the energy released in the dark/normal sock in the ashing cycle has not yet been determined.

Note also that this is why we wear dark socks to bed -- if we were to put them in the hamper with regular socks, the dark socks might come into contact with our light socks and explode.

Way to go

[Cryacin]

Shining some light on dark matter.

Re:Way to go

[Ian Alexander]

From the article:

I’ll note: this has nothing to do with dark matter. As it happens, 90% of the matter in the Universe is in a form that emits no light, but affects other matter through gravity. We know it exists, and you can find out why here. We know it exists locally, in nearby galaxies and clusters of galaxies, too. This new result doesn’t affect that, since the now un-hidden galaxies are very far away, like many billions of light years away. They can’t possibly affect nearby galaxies, so they don’t account for dark matter.

This will change the ratio of luminous matter:dark matter but not eliminate dark matter entirely.

Not that you said that it would necessarily get rid of dark matter, but it was a conclusion that suggested itself from the summary's wording.

Re:Dark stuff?

[synaptik]

You've confused dark socks with anti-socks. Your theory fails.

Re:MOD PARENT UP

[Dogtanian]

Slashdot readers never bother reading the article.

Pffftttt.... I didn't even bother reading the summary. Come to think of it, I don't think I looked at the headline either.

Er, but I'm guessing it was something to do with the seventh-generation iPhone. Anyway, whatever it was, I'm sure it'll be great- congratulations Steve, and all the Slashdotters dragging this thread offtopic rambling about astronomical nonsense should be ashamed of themselves.

Re:A Nice Step

[arth1]

No, I meant quantum leap as in literally a quantum leap.
An electron dropping from orbital L3 to L2 instead of L2 to L1 is exactly what sends out photons of a more detectable temperature.

Re:A Nice Step

[AlamedaStone]

No, I meant quantum leap as in literally a quantum leap.
An electron dropping from orbital L3 to L2 instead of L2 to L1 is exactly what sends out photons of a more detectable temperature.

...and hoping each time that its next orbital drop would be the drop home.

Re:Mod parent down

[steve_bryan]

It is imprecise to say physicists indicate there should be much more mass in the universe. What they say is that there is mass missing in every galaxy which implies it is missing from the universe but only on a galaxy by galaxy basis. Dark matter is necessary to explain why galaxies form. In other words the "missing" matter is in each and every galaxy. Discovering more galaxies doesn't affect that issue.

When I was a physics major in the dark ages they were just beginning to notice that computer simulations based on observed stellar quantities and masses had the annoying property of never resulting in galaxies. In subsequent years it was computed that the needed mass for galaxy formation wasn't off by a little but actually by a huge factor.

Eventually some observations of gravitational lensing have provided more evidence that there was huge amounts of mass measured in this indirect fashion that was simply not seen by exhaustive charting of the observed stars.