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Researchers detect possible signal from Dark Matter
- Thread starter Amir0x
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backflip10019
Member
So... in layman' terms, what does this mean? I understand what dark matter is, but what's the significance of this discovery?
John Kowalski
Banned
so it's not dark matter anymore right
TheSadRanger
Banned
Dark Matter is one of the two biggest cosmic mysteries in our universe. If we can isolate it and see it, truly know what it is for the first time, we discover a gravity source many times larger than every star, planet, comet, black hole, etc in the universe combined.
It's properties could give us new laws of physics and open the door to the next big era in scientific discovery, and this was ALWAYS one of the big things that could happen in our lifetime.
The other is Dark Energy.
We still have no clue what it is, other than it may be heretofore unseen or undetected particles, so the place-holder sticks.
It was proven 80 years ago when we discovered all the things we can see in the universe don't account for all the gravity, we just have no fucking clue what it is.
M0nochromatic
Member
Up to 80% of the universe is made up of a kind of matter that we know next to nothing about.
That amazes me. I'm eager to see what comes out of the report.
That amazes me. I'm eager to see what comes out of the report.
SigmasonicX
Member
And to explain what dark energy is, it's the energy to explain why, despite all of the gravity present, objects in the universe are not just spreading away from each other, but actually accelerating.
Poodlestrike
Banned
I've always found dark matter kind of mind blowing. It's such an odd thing, we found the limits of our knowledge, and used dark matter to fill in the gap. If we can finally learn more about it...
So cool!
So cool!
That quote is wrong. It's something like this:
3% normal matter.
27% dark matter
70% dark energy
D
Deleted member 80556
Unconfirmed Member
Exciting! It'd be a further confirmation about the Standard Model, right?
I'm very curious about this too.
I'm very curious about this too.
terrisus
Member
It doesn't matter, don't waste your energy.
Dark matter is the unknown gravity in our universe. We can quantify all the gravity from all the planets, stars, etc and get a number, and the real number is WAY higher. That's how we know Dark Matter exists, without knowing what it is.
Dark energy was only proven in your lifetime. With all this gravity, the universe's expansion should be slowing down after the Big Bang. So when two teams of astronomers set up to measure the speed decay (by isolating a supernova and measuring the speed at which it's moving), they discovered that the universe is actually speeding up. Which means there's a force greater still than all the gravity in the universe (including Dark matter) working opposite the gravity. The calculable gravity of dark matter, and the calculable force of dark energy is how we get the 4% known, 26% dark matter, 70% dark energy make-up of the universe.
The only thing dark about either dark energy or dark matter is our inability to see or detect exactly what they are (to this point). We don't know that dark energy is energy at all, or that dark matter is matter at all. The names are 100% placeholder.
D
Deleted member 80556
Unconfirmed Member
So interesting. So they don't really fit in the Standard Model then?
Dark matter- majority of the 'stuff' in the universe that scientists believe only interact through gravity.
Dark energy- data indicates that galaxies are moving away from each other, however observations have concluded that these things are moving away faster than we once believed. Whatever it is that's making these galaxies move away from each other at this increased rate is what we believe dark energy to be.
If dark matter was any known particle, we should be able to detect and identify it pretty easily. We can't.
They could be new particles that we don't have the technology to detect or some think it might be the "leaking" effect of another universe, many times bigger than our own, but it's 100% speculative until we can put something under a metaphorical microscope.
Short answer: Not a clue.
The standard model was used to predict two possible kinds of particles as candidates for dark matter and how to detect it. Hence the signal. We know what to look for.
They are the blanks we need to explain concenring two different observed phenomena:
Dark Matter is the unaccounted-for mass that exerts the gravitational forces that we can observe holding galaxies together. If Dark Matter didn't exist, all of the galaxies we can observe would have flung themselves apart. Basically, we can see the gravitational force it exerts, but can't see the source of this force. Dark matter is the name we have for this question that needs to be answered.
Dark energy is the energy that is fueling the accelerating expansion of the universe. By all logic based on what we know of the laws of physics, gravity should be causing the objects in the universe to grow closer to each other, slowing and then reversing the expansion of the universe that started with the Big Bang. However, that isn't happening. Instead, all observations point to the fact that the universe is expanding at an accelerating rate, and we have no idea why. Dark energy is thus the completely unknown force that is separating galaxies from each other. Also, the amount of energy required to do this is tremendous, completely dwarfing all of the energy contained in every star in the universe combined. It is a gigantic hole in our understanding of the universe.
EDIT: It is important to point out that dark matter and dark energy might not be matter or energy at all. Instead, it is better to describe them as gaps in our understanding of the laws of physics. Similar discrepancies, such as oddities in the orbit of the planet Mercury that could not be explained by Newtonian physics, were solved when we threw out Newtonian physics in favor of Einstein's Theory of General Relativity and the discovery of quantum mechanics. Solving the issue of dark energy in particular will likely require another massive rethinking of everything we know about the laws of our universe.
ersocaster
Member
This would be pretty neat.
My physics is a bit outdated, but I think the biggest difference between dark energy and dark matter as it applies to us is dark energy is more usable. A lot of models we have for technologies require dark energy, such as the warp drive.
My physics is a bit outdated, but I think the biggest difference between dark energy and dark matter as it applies to us is dark energy is more usable. A lot of models we have for technologies require dark energy, such as the warp drive.
Not exactly. Stuff like the the warp drive requires theoretical exotic matter, such as objects with negative mass. They are based on exotic solutions to existing physical equations. Dark matter and dark energy aren't things we can describe the practical benefits of, since we don't even know what they are.
M0nochromatic
Member
Interesting. I didn't know that, but I'm still excited about humanities' research into the unknown(even if it's a smaller amount of unknown).
I love reading about new scientific news like this, similar to a thread earlier in the year about scientists "freezing" light. Even if no practical use comes from it, atleast someone's investigating something out there.
"Very Dim Matter", possibly?
I'd love for us to find a way to legitimately detect and study dark matter. Or a fraction thereof of it. But as Lawrence Krauss once said, much of physics is not yet ready for public consumption. So I don't know what they are reporting on when things are still up in the "air" so to speak.
CraigerGamer
Member
or maybe our theories and equations are completely wrong and there really is no mysterious energy or matter that we can't measure.
My least favorite theory in Astro/Particle Physics.
Randolph Freelander
Member
My money is still on dark matter being the Stay Puft Marshmallow Man.
NobleXenon
Member
It fits pretty well:
Everything outside of the circle is what may be dark matter.
loaf of bread
Member
We'll have hover cars mass producing in roughly 3 months.
Randolph Freelander
Member
Beaniedude
Member
I never liked Dark Matter.
Astronomers be like, "Our models say that the universe is lighter than it is... I know. We can handwave this away by introducing a mysterious mass source that we can't detect."
But this is cool.
Astronomers be like, "Our models say that the universe is lighter than it is... I know. We can handwave this away by introducing a mysterious mass source that we can't detect."
But this is cool.
You mean love?
Dark Matter Earth has found us.
I never liked Anecdotes.
People be like, "My experience trumps vetted experiments, measures, and working models. We can handwave convergent evidence by introducing doubt and dismissal against things we have no knowledge of."
But you're probably right.
To give you the benefit of the doubt, we can detect many particles. We can also detect that some of them only interact with a handful of other particles. We can detect mass where there is no normal matter. We also know that particles can form out of what is seemingly nothingness, as evident by hawking radiation. So it is a mystery, but there is no reason to wave doubt that there isn't something there. Seeing is believing and we see there is clearing something.
DiscoJer
Member
I can't help be reminded of the "ether", which scientists created because they needed something to explain how light waves propagated.
Or back to the geocentric theory, when scientists observed that it didn't fit observations, they came up with tweaks to it to try to explain what they saw, when the real answer was the heliocentric theory (which ironically was rejected by the Ancient Greeks because they couldn't detect parallax in stars and thus couldn't prove it)
Or back to the geocentric theory, when scientists observed that it didn't fit observations, they came up with tweaks to it to try to explain what they saw, when the real answer was the heliocentric theory (which ironically was rejected by the Ancient Greeks because they couldn't detect parallax in stars and thus couldn't prove it)
SigmasonicX
Member
And your point is? Scientists have to work with what they have, and form hypotheses that they test with experiments. If these signals produce good results, then the dark matter theories will be adjusted in kind. Ether and geocentricity were perfectly valid theories that were disproved, and unlike the latter, I don't expect that there would be any religious basis for holding onto the idea of dark matter even after there is evidence against it.
When I was single I used to balance my checkbook like that occasionally.
I think that's a misunderstanding. Dark Matter isn't an explanation, it is a description of an open question. It is something where scientists are openly admitting that they don't have all the answers. It is entirely possible that we will need to rethink the equations that are giving us these results, and most physicists would probably be gleeful to discover something that completely throws out the existing book.
maniac-kun
Member
Maybe the standard model is just wrong.
A sterile neutrino is a neutrino with right-handed chirality, whose existence is motivated on the basis that other fermions have both left- and right-handed components, whereas the neutrinos that we detect are left-handed only. It also potentially ties into the method ("the seesaw mechanism") that scientists have proposed by which neutrinos gain a tiny amount of mass (the standard model as it currently stands predicts that they are massless, but experimentally, this has been shown to be untrue). It's one of the hypothetical candidates of weakly interacting dark matter that doesn't necessarily require the existence of supersymmetry. This indirect detection focuses on a 3.53 keV photon emission line that may have been produced by dark matter annihilation.
It's prudent to remain cautious about this though - there have naturally been a large number of false alarms, and many indirect detection experiments have reported a potential dark matter signal.
Some submissions on the arXiv from this team and another regarding the existence of a 3.53 keV signal from the Milky Way centre (consistent with emissions from the Andromeda galaxy and Perseus cluster), for those who wish to read them. Bear in mind that atomic line emission is not conclusively ruled out.
http://arxiv.org/abs/1402.2301
http://arxiv.org/abs/1408.2503
http://arxiv.org/abs/1411.0311
On a more general note, it does seem rather likely that dark matter is a form of weakly interacting particle that is not yet described in the standard model. Some evidence for this comes from a rather beautiful imaging of the bullet cluster by the Chandra X-ray observatory:
This is a composite, false-colour image of a pair of galaxy clusters that have collided with each other. The pink parts of this image correspond to hot, X-ray emitting gas. The blue parts correspond to mass that has been determined to exist from gravitational lensing (there's much more of it than can be explained by contributions from the optical galaxies and hot gas). There's a clear separation of the two, since the dark matter has not interacted with the rest of the matter except via gravity, and has effectively phased right through the collision.
The standard model is a beautiful and self-consistent model of physics, but there are certainly a lot of missing pieces of the puzzle, dark matter and dark energy being just a couple of them (for example, there's the Higgs hierarchy problem, the strong CP problem, the fact that gravity has not yet been unified with the other three fundamental forces, etc). There is almost certainly a rich variety of physics yet to be discovered beyond the standard model.
It's prudent to remain cautious about this though - there have naturally been a large number of false alarms, and many indirect detection experiments have reported a potential dark matter signal.
Some submissions on the arXiv from this team and another regarding the existence of a 3.53 keV signal from the Milky Way centre (consistent with emissions from the Andromeda galaxy and Perseus cluster), for those who wish to read them. Bear in mind that atomic line emission is not conclusively ruled out.
http://arxiv.org/abs/1402.2301
http://arxiv.org/abs/1408.2503
http://arxiv.org/abs/1411.0311
On a more general note, it does seem rather likely that dark matter is a form of weakly interacting particle that is not yet described in the standard model. Some evidence for this comes from a rather beautiful imaging of the bullet cluster by the Chandra X-ray observatory:
This is a composite, false-colour image of a pair of galaxy clusters that have collided with each other. The pink parts of this image correspond to hot, X-ray emitting gas. The blue parts correspond to mass that has been determined to exist from gravitational lensing (there's much more of it than can be explained by contributions from the optical galaxies and hot gas). There's a clear separation of the two, since the dark matter has not interacted with the rest of the matter except via gravity, and has effectively phased right through the collision.
maniac-kun said:
The standard model is a beautiful and self-consistent model of physics, but there are certainly a lot of missing pieces of the puzzle, dark matter and dark energy being just a couple of them (for example, there's the Higgs hierarchy problem, the strong CP problem, the fact that gravity has not yet been unified with the other three fundamental forces, etc). There is almost certainly a rich variety of physics yet to be discovered beyond the standard model.
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