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

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."

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."

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

[maxwell demon]

Actually it's the Overwhelmingly Large Telescope.

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.

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: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.

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.