Telescope to Hunt for Missing 96% of the Universe

One of astronomy's greatest riddles may be on the way to being solved

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C. Carreau / ESA
C. Carreau / ESA

An artist's impression of Euclid.

Scientists are in the business of solving mysteries—or trying to, anyway. That’s true across all disciplines, but astronomers and physicists are the only ones who get to think about questions that are literally cosmic.

And even in that rarefied category, in which the subject matter ranges from black holes to neutron stars to the search for Earth-like planets across interstellar space, it doesn’t get any more esoteric than the ongoing quest to uncover the secrets of dark matter and dark energy. Together, they make up a whopping 96 percent of the cosmos—but to this day, nobody can say with any confidence what either one of them actually is.

The European Space Agency (ESA) is hoping to change all that: by 2020, if all goes according to plan, the Euclid space mission will go into orbit, trying to sniff out the nature of these similarly named but (presumably) unrelated phenomena. And now, NASA is on board as well: a few weeks ago, the space agency formally joined the Euclid project, funding 43 U.S.-based scientists to work with their international counterparts. “Once Europe commits to a mission, they do it,” says Charles Bennett, of Johns Hopkins University, part of the NASA contingent, who has served on “more committees than I care to think about” trying to get a similar U.S. undertaking off the ground. While America dithered, Europe moved, and NASA’s best option to participate in the cutting-edge research meant accepting an unfamiliar supporting position on the mission.

(MORE: Dark Matter Mystery: Why Are 400 Stars Moving as if There’s Nothing There?)

The matter of whose flag goes on the telescope pales, however, compared with the grandeur of the questions Euclid could help answer. The mystery of dark matter goes all the way back to the 1930’s, when Caltech astronomer Fritz Zwicky noted that some galaxies seemed to be orbiting each other so fast that they should be slowly separating—each galaxy remaining discrete and intact, but the distances among them opening wider and wider. In the 1960’s, the Carnegie Institution’s Vera Rubin and others realized that something similar ought to be true within individual galaxies—that they were whirling so fast they should rip themselves apart. And by the 1980’s, astronomers were forced to accept the idea that the gravity from some mysterious, invisible form of matter had to be holding them all together.

Today, the consensus is that dark matter consists of vast clouds of some still-undiscovered subatomic particle that surround galaxies and galactic clusters. The shapes and sizes of those clouds could provide a valuable clue to the particles’ properties, and while Euclid can’t see the clouds directly (“dark” here is a synonym for “utterly invisible”), it can deduce their shapes and sizes by looking at the galaxies that lie beyond them.

“We’ll use a technique called ‘weak lensing,’” says Jason Rhodes, of the Jet Propulsion Laboratory, the research leader of the NASA contingent. “It’s my particular area of interest, and it’s what got me interested in Euclid in the first place.” The idea, based on Einstein’s General Theory of Relativity, is that a massive foreground object warps spacetime, distorting the images of objects in the background. To map out the dark matter in a nearby cluster of galaxies, therefore, you look at the distortions of thousands of other galaxies behind it; the pattern of distortions tells you the size and shape of the dark-matter cloud that must have caused it.

(MORE: Crowd-Sourcing Science: Find the Dark Matter)

Dark energy is something entirely different—indeed, in some ways it’s the exact opposite: it’s a still-unknown force, discovered in the 1990’s, that makes the universe expand faster and faster all the time. (Einstein originally came up with this idea, but eventually abandoned it). You can think of dark energy as a type of antigravity, but exactly what type — whether it fluctuates in strength over time, for example — is yet to be determined.

Euclid will tackle this problem as well, by looking at the distances among tens of millions of galaxies at many different stages of cosmic history—with objects more distant from Earth representing images that come to us from earlier in time. Using measurements of the primordial light left over from the Big Bang, theorists can predict how those distances should change as the universe evolves, both with and without dark energy in its various possible forms. By comparing the theories with what Euclid actually sees, they’ll be able to get a handle on which theory matches what’s happening in the cosmos.

(MORE: Dark Energy: Astronomers Inch Toward Solving Space Riddle)

Euclid probably won’t solve the mysteries of dark matter or dark energy by itself. “These are big questions,” says Bennett, “and it’s not possible to do everything with one satellite.” At the same time the Euclid team is gearing up, physicists are thus searching for individual dark-matter particles here on Earth, for example, since they should pervade, not just surround, the Milky Way. But without complementary measurements from Euclid and other cosmic dark-matter searches, says Rhodes, “we wouldn’t know how dark matter behaves in bulk.”

As for dark energy, telescopes on the ground are already trying to do the same sort of measurements Euclid will do from space, and while the Europeans’ orbiting telescope will be free from atmospheric distortion, its relatively small mirror means it can’t easily detect light from the faintest galaxies. In coming years, the U.S.-built Large Synoptic Survey Telescope could significantly expand this ground-based campaign. And a new Hubble-like space telescope donated to NASA free of charge by the National Reconnaissance Office could become Euclid’s partner in orbit.

That growing mix of high-tech eyes looking steadily up and out is exactly what’s needed for puzzles as big as dark mater and dark energy, says Bennett. “My advisor at MIT, Bernie Burke, used to tell me ‘you can’t discover anything unless you’re looking at the sky,’” he recalls. Obvious? Maybe, but when you’re trying to answer these most cosmic of questions, it’s not a bad thing to keep in mind.

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20 comments
mpc755
mpc755

The Milky Way's halo is what is referred to as the curvature of spacetime.

The Milky Way's halo is the state of displacement of the aether.

The geometrical representation of gravity as curved spacetime physically exists in nature as the state of displacement of the aether.

Displaced aether pushing back and exerting inward pressure toward matter is gravity.

richardomer
richardomer

Nikola Tesla (who invented death rays and other stuff) did not like Einstein's theories.  Tesla said "Space is a vacuum and a vacuum is nothing.  How can nothing be curved?" But we know that Einstein was right becuase we've seen the curvature of space.  This "dark energy" expansion does not have anything to do with movement - rather, things are getting further apart - like dots on a balloon that is being inflated.

paul.alan.robertson
paul.alan.robertson

@richardomer That's a particularly bad quote from Tesla.  It's not that space *is* a vacuum, space generally *contains* a vacuum, unless it's some of the lucky space that contains matter, like ours.  

profunooosss23
profunooosss23

The universe is also the empty space not only the matter why the think that the gap between galaxies has to be filled with ''something''?

TheDisclosure
TheDisclosure

This is a foolish post- the universe is never ending and thus has no beginning. Time to understand.

richardomer
richardomer like.author.displayName 1 Like

@TheDisclosure There is something called Obler's Paradox which says that if the universe was infinite then the sky would be bright in all directions day and night.  The same logic would apply to an eternal, yet finite universe.

DeweySayenoff
DeweySayenoff

@TheDisclosure So, TheD, it's time for YOU to understand.  You'll have to submit your observed and repeatable data and method of acquiring that data supporting your conclusion to a scientifically accredited journal for peer review to determine the validity of your conclusion.  Once that conclusion has been proven based on your data, then someone else might actually take you seriously. 

 Currently, the size of the observable universe is 98 billion light years, proven by repeatable and verified methodology.  Beyond that, it's not certain because it hasn't been measured.  What it MIGHT be isn't verified, or currently verifiable.  So if you have some data and a method no one else has, please share.  If it's all based on mythology or supposition, perhaps you should try the scientific method as an experiment in independent thinking.

It sounds like you could use it.

TheDisclosure
TheDisclosure like.author.displayName like.author.displayName like.author.displayName 3 Like

@DeweySayenoff @TheDisclosure The big bang recently was disproved my friend. The recent discovery of the largest quasar proves this. All you have to do is discover, the electric universe is getting proved more and more every day. Scientific patents by Tesla and others were thought to be false, but if you put the time into it, you realize his magnifying transmitter and the zero point energy field do exist. Delve into science that isn't mainstream, along with the news. If you stop paying attention to current mass-media mythology and do some of your own research, you'll discover the truth. The fundamental laws of physics are in essence obsolete and need to be reformed. I've created one of my one OU devices that harnesses energy from the ether. So Dewey, before you come running to me with your proven papers, I simply ask you to discover for yourself the truth, and not be blinded by conceptualism. 

brantc.174
brantc.174 like.author.displayName 1 Like

@paul.alan.robertson @TheDisclosure @DeweySayenoff 

The Aether has never been disproven.... There are crazier things out there like Dark Matter, Dark energy, The Big Bang etc...  Gravity is broken and we dont have a UFT... 

The right kind of Aether would solve that... Aetherometry.com
How does the sun work....

Oh we dont know but we guess its a large controlled fusion bomb...

If you do your own research and dont just believe  mainstream hype, you will see there are intractable problems with physics that may require an aether... Virtual photons and zero point energy are not that far off...

Our model of the way the universe works and our interpretation of phenomena is most likely wrong but for engineering it works...

Swedge70
Swedge70

@TheDisclosure @DeweySayenoff Not only was the big bang recently disproved, but they also found the oldest dinosaur.  It's approximately 6000 years old, and was ridden by Cain when he was exiled after killing his brother, Abel.

KBangert
KBangert

@TheDisclosure @DeweySayenoff inspiring post Disclosure.. Huge fan of Elon Musk. I do not by any means discredit our current foundation of physics..However, I wholeheartedly believe questioning our existence and founding principles is mandatory as we continue to inhabit this Earth. GodSpeed with your work and eternal curiosity.

Jodun
Jodun like.author.displayName 1 Like

@TheDisclosure I saw a Hobbit the other day, right out my front door standing next to my car in the driveway. You should believe this because I tell you it is true and because I am now going to tell you that anyone who claims that Hobbits are merely fictional characters created by J. R. R. Tolkien is part of a vast media conspiracy to hide the truth. I will offer you no evidence beyond my word that Hobbits exist and tell you that you need to start reading through all of the pro-Hobbit conspiracy websites (which I won't actually tell you how to find) to find "the truth" that "they" do not want you to see. I won't actually provide any evidence or proof, because I don't need to. As a random poster on the Internet you should believe me just because I've made the claim that I saw a real live Hobbit.

Does this sound familiar?

ThePlatznerPost
ThePlatznerPost

Space Hunt!!! Sharing on The Platzner Post Facebook, and Twitter

US1776
US1776 like.author.displayName like.author.displayName like.author.displayName like.author.displayName 4 Like

There is a fundamental flaw in our understanding of the universe.

Some of the equations now produce either impossible or undefined results.


Time to revisit assumptions.


.

PFO'Neill
PFO'Neill like.author.displayName like.author.displayName 2 Like

String theory proposes an 11 dimensional universe in which gravity acts throughout 10 of the dimensions. Furthermore, it raises the possibility that objects with mass could exist in the 7 dimensions that we cannot observe directly. Might "dark matter" be conventional matter that is unobservable in our 4 dimensions but which nevertheless exerts a gravitational force on us?

DeweySayenoff
DeweySayenoff

@PFO'Neill It's best to learn the equations and see exactly to what they relate and how they interrelate before asking that.  The answer is probably no, by the way, but it's not a bad guess.  Something like that could be measured through direct observation, even if the data didn't match the anticipated model.  In this case, the model works, but the observed mass is inadequate for the model's calculation.  The dimensions you mentioned don't allow for gravitational cross-over, but deal with other things.

The prevailing theory behind dark matter is WIMPS (Weakly Interacting Massive Particles).  They don't clump together but remain separated.  Hence the weakly interacting part. They generally don't form 'gasses' as other atoms do.  But their mass is theorized to be far greater than one would expect.  They originated with the start of the universe as part of the matter/antimatter ratio and have some similarities to it.  Matter and antimatter "annihilate" one another, of course, but all that means is energy is released.  And E=MC^2 means that it's also matter.  So all the missing mass of the original Big Bang is out there, only in different forms, perhaps mass, perhaps only energy.  

That means means the original mass of the universe remains as E/C^2=M.  So the theory goes that WIMPS are is an Occam's Razor solution to fit the observed behavior of visible mass into the general relativity model better than postulating a gravitational force from another dimension interacting with mass in the observable dimensions.  And this is what the telescope may be seeing.

My guess is that dark matter and dark energy are the result of the initial big bang annihilation of matter and antimatter.  That massive release of energy is why the universe is actually flying apart rather than contracting, and the dark matter is a very small amount of "re-condensed" energy from annihilated mass into an exotic form of mass that can't interact very well with each other due to the nature of its origin, but still exerts gravitational effects.

If E=MC^2, then there is a massive amount of both energy and mass unaccounted for in the universe.  And if you look at what dark energy and dark matter do, my guess tends to make more sense in a standard model kind of way, than many other explanations of their origins.

Just a passing thought of mine.

It's nice to have mysteries.  Life would be really boring without them.  And it keeps mathematicians and theoretical physicists off the streets.