Much ado about nothing: Astronomers use empty space to study the universe

August 11, 2016, The Ohio State University
This simulation of the large-scale structure of the universe reveals the cosmic web of galaxies and the vast, empty regions known as voids. Credit: Nico Hamaus, Universitäts-Sternwarte München.

Researchers who are looking for new ways to probe the nature of gravity and dark energy in the universe have adopted a new strategy: looking at what's not there.

In a paper to appear in upcoming issue of Physical Review Letters, the international team of astronomers reports that they were able to achieve four times better precision in measurements of how the universe's visible matter is clustered together by studying the empty spaces in between.

Paul Sutter, study co-author and staff researcher at The Ohio State University, said that the new measurements can help bring astronomers closer to testing Einstein's general theory of relativity, which describes how gravity works.

Sutter likened the new technique to "learning more about Swiss cheese by studying the holes," and offered another analogy to explain why astronomers would be interested in the voids of space.

"Voids are empty. They're boring, right? Galaxies are like the cities of the universe, full of bright lights and activity, and voids are like the miles and miles of quiet farmland in between," Sutter explained.

"But we're looking for bits of evidence that general relativity might be wrong, and it turns out that all the activity in galaxies makes those tiny effects harder to see. It's easier to pick up on effects in the voids, where there's less distraction—like it's easier to spot the glimmer of a firefly in a dark cornfield than in a lit-up city bustling with nightlife."

The voids, he pointed out, are only empty in the sense that they contain no normal matter. They are, in fact, full of invisible , which is causing the expansion of the universe to accelerate.

While Einstein's 1915 general theory of relativity goes a long way toward explaining gravity in the universe, Einstein couldn't have known about dark energy. That's why, today, astronomers are working to find out whether the rules of general relativity hold up in a universe dominated by it.

Sutter, in Ohio State's Department of Astronomy, worked with colleagues in Germany, France and Italy to compare computer simulations of voids in space with a portion of data from the Sloan Digital Sky Survey. The statistical analysis revealed a four-times improvement in precision in their models of matter density and the growth of cosmological structure when they took the physics of voids into account.

They were looking for tiny deviations in void behavior that conflicted with , and they found none. So Einstein's theory of gravity holds true for now. The analysis and models are publicly available online, so the researchers hope that others will use them to do further work in the future.

"Our results demonstrate that a lot of unexplored cosmological information can be found in cosmic voids," Sutter concluded. "It's truly like getting something from nothing."

Explore further: Black holes banish matter into cosmic voids

Related Stories

Black holes banish matter into cosmic voids

February 24, 2016

We live in a universe dominated by unseen matter, and on the largest scales, galaxies and everything they contain are concentrated into filaments that stretch around the edge of enormous voids. Thought to be almost empty ...

Scientists' breakthrough in modelling universe

June 24, 2016

Research teams in Europe and the USA – including a cosmologist from the University of Portsmouth – have begun modelling the universe for the first time using Einstein's full general theory of relativity.

Cosmologists weigh cosmic filaments and voids

April 17, 2014

(Phys.org) —Cosmologists have established that much of the stuff of the universe is made of dark matter, a mysterious, invisible substance that can't be directly detected but which exerts a gravitational pull on surrounding ...

Relativity of rotational motion confirmed

May 12, 2016

It has been one hundred years since the publication of Einstein's general theory of relativity in May 1916. In a paper recently published in EPJ Plus, Norwegian physicist Øyvind Grøn from the Oslo and Akershus University ...

Recommended for you

See a passing comet this Sunday

December 14, 2018

On Sunday, Dec. 16, the comet known as 46P/Wirtanen will make one of the 10 closest comet flybys of Earth in 70 years, and you may even be able to see it without a telescope.

Mars InSight lander seen in first images from space

December 14, 2018

On Nov. 26, NASA's InSight mission knew the spacecraft touched down within an 81-mile-long (130-kilometer-long) landing ellipse on Mars. Now, the team has pinpointed InSight's exact location using images from HiRISE, a powerful ...

Video: Enjoying the Geminids from above and below

December 14, 2018

On the night of December 13, into the morning of December 14, 2018, tune into the night sky for a dazzling display of fireballs. Thanks to the International Space Station, this sky show – the Geminids meteor shower—will ...

20 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

BackBurner
1.6 / 5 (7) Aug 11, 2016
Well this is an idea more than a little late to the party.
baudrunner
1.9 / 5 (14) Aug 11, 2016
It may be that there is no dark energy and that the universe is not really expanding the way we think it is and that we may require a paradigm shift of our perceptions of what is really going on. For one thing, it has now been determined that from anywhere you are in the universe, one observes not everything moving away from one's reference point, but objects actually moving in many directions away from one's reference point. The star Sirius, 8.2 light yrs away, is actually approaching us.

Check out this slow-mo video of a bursting soap bubble. https://www.youtu...tuXJ8BGk It may be that we occupy galactic strings that are the residue of a similar process occurring in the cosmos. That would resolve the dark energy problem and explain the way that the universe is expanding.
IMP-9
4 / 5 (16) Aug 11, 2016
The star Sirius, 8.2 light yrs away, is actually approaching us.


The Galaxy is gravitationally bound, it's not expanding nor does anyone claim it is. The Andromeda galaxy is also approaching even at 2.3 million light years distant but again, this is the small scales where local gravitational forces can dominate over the expansion of the universe. Beyond a few 10's of millions of light years the Hubble flow takes over, all galaxies beyond this distance are receding.
arom
Aug 11, 2016
This comment has been removed by a moderator.
_ProudChristian_
1 / 5 (10) Aug 12, 2016
The universe will seemingly continue to expand as long as these astrophysicists keep probing it, and it will do so at an accelerated pace b/c astrophysicists' "meddling," and the sophistication of their equipment & methods, show no sign of abating--and the universe must simply keep pace, if not be many steps (more like light years) ahead!

Same on the other end of the spectrum: sub-atomic particles will continue to pop up, and weird phenomena will perplex, as long as physicists keep poking the quantum world...

It's rather a universal law, that we shouldn't "hit a wall", lest we get all bored and depressed and existential!

If I were one of these scientists, I'd soothe my brain once and for all and look into the mystery of human curiosity.
trevor_white
4.2 / 5 (5) Aug 12, 2016
there may be another tipping point at which the expansion, governed by the results of Eisenstein theories, will change given his description of gravity.
antialias_physorg
4 / 5 (12) Aug 12, 2016
given his description of gravity.

Now THAT I want to see you explain how you deduce that from the description of gravity. Please. Do.

The universe will seemingly continue to expand as long as these astrophysicists keep probing it, and it will do so at an accelerated pace b/c astrophysicists' "meddling," and the sophistication of their equipment & methods, show no sign of abating--and the universe must simply keep pace, if not be many steps (more like light years) ahead!

...wow...another crazy has joined. And why doesn't the nick surprise me after reading the content?
physman
4.3 / 5 (8) Aug 12, 2016
@_ProudChristian_ what are you advocating, that we go back to the stone age? You do realise that quantum mechanics and those strange particles you talk about are the very things that power the chips in your computer? If everyone that has worked on science throughout history had as weak a mind as you we would all be ploughing the fields and dying at 30. Give me 70 years of intriguing and perplexing scientific problems over 30 years of ignorance and blind faith any day.
Azrael
4.2 / 5 (5) Aug 12, 2016
...wow...another crazy has joined. And why doesn't the nick surprise me after reading the content


Not sure why, but I feel the need to point out that not all christians share this one persons viewpoint...

Not all christians think science is evil, the Earth is 6000 years old, and dinosaur bones were put there by Satan to deceive them.

Not all Muslims are boy-buggering terrorists who want to start a world war to bring about the 13th imam.

Not all Luciferians actually worship Lucifer. Many if not most disbelieve in anything supernatural at all.

Check your bias.
davek
4 / 5 (5) Aug 12, 2016
I know that values are generally believed constant in the universe (ie, speed of light, relative strength of the four forces) Still, what if the Higg's field was inconsistent throughout the universe?

To my mind that could:

1) Explain the uneven distribution of matter in the universe.

2) Mean that although the force of gravity itself would be constant, the effect would be less in empty areas. As the area expanded, the Higgs field would continue to become weaker, allowing the area to expand faster, explaining dark energy.

3) Suggest that a slightly stronger Higgs field in densely populated areas (galaxies and clusters) could have a noticeable effect on an object the mass of a galaxy but possibly not the mass of solar system, explaining dark matter.

I am sure I fail to understand something and would love for someone who actually knows the science to explain it to me.
tinitus
Aug 12, 2016
This comment has been removed by a moderator.
Captain Stumpy
3.7 / 5 (9) Aug 12, 2016
Check your bias
@Azrael
for starters, it's not bias if it's demonstrated or provable, especially considering the x-tians on this particular site and their typical posts or floods of pseudoscience or religion

for two: religion of any sort typically centers around a faith which is, by definition, a belief in something without evidence

Although being religious or x-tain doesn't exclude you from being a scientist, when it's used in conjunction with science in order to justify a belief (like, say: jvk, or other anti-evolution posters) then it's detrimental to the function of gaining factual knowledge

this means, by definition, it's biased and *not science* - hence the need to separate the two

i won't say all x-tians believe as the delusional nutbag above does

but the simple fact is that there is no evidence supporting the x-tian beliefs at all
- therefore it just. aint. science.

why bring it up at all in a science site discourse where it's irrelevant?
vidyunmaya
1.4 / 5 (9) Aug 12, 2016
sub: need to catch-up with Visible-invisible matrix
Super-imposition of the above on the Milky-way Galactic Frame requires new modes of Reflector cosmos Lensing.space Time Energy concepts must catch-up with Cosmic function of the universe- dynamic Cosmos Quest.15 Books at LULU. http://www.lulu.c...jnani108
antialias_physorg
4.2 / 5 (10) Aug 12, 2016
Not sure why, but I feel the need to point out that not all christians share this one persons viewpoint...

Check your bias

Not all christians think science is evil, the Earth is 6000 years old, and dinosaur bones were put there by Satan to deceive them.

I'm aware of that. You need to understand the difference between correlation and causation. Being a christian doesn't cause 'crazy'. But the likelyhood of 'crazy' being sourced from a christian (on this site) is a lot higher than from an atheist.

So when I say I'm not surprise "AFTER reading the content" when looking at the nick I'm clearly talking about the correlation.
If I had said something like "I looked at the nick and knew that this post was going to be crazy" THEN you'd have a point about bias.

(To be fair: if I had read the nick first I would have known that the content would be crazy. Not because of the 'christian', but because of the 'proud'. Anyone who uses that word is insane.)
Azrael
5 / 5 (4) Aug 15, 2016
@antialias_physorg

Please forgive my knee-jerk reaction. I see now that I read too much into your response.

I've been reading the comments section on this site perhaps too much recently, and have noticed an uptick in ostensibly intelligent people bashing people's political affiliations, countries of origin, faiths, etc. It seems to have become the new "cool", and it's contributing to my loss of faith in humanity.

Time to take a break, I think.
tinitus
Aug 15, 2016
This comment has been removed by a moderator.
LifeBasedLogic
Aug 15, 2016
This comment has been removed by a moderator.
Hyperfuzzy
1 / 5 (6) Aug 15, 2016
Maybe if we reviewed the void in logic we will see our theories are bogus.
RNP
3 / 5 (4) Aug 16, 2016
@davek
I know that values are generally believed constant in the universe (ie, speed of light, relative strength of the four forces) Still, what if the Higg's field was inconsistent throughout the universe?


I think that can be ruled out, as a varying Higgs field would result in the masses of the electrons and nucleons varying, and this is ruled out by spectroscopic observations of the non-variability of relative line positions. e.g. http://arxiv.org/...01.05533

The reference is for a single high redshift observation, but such effects would show up in any sufficiently broad spectroscopic observations.
BongThePuffin
Aug 16, 2016
This comment has been removed by a moderator.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.