0
Any matter, normal (visible) or dark (invisible), can be noticed by its gravitational attraction. There are several pieces of evidence, all based on the gravitational attraction of some matter that is invisible, but must be there because it has gravitational effects. These include the fact that galaxies rotate way too fast for the amount of known matter, studies on gravitational lensing, and several other pieces of evidence.
Gillian Watsica
Wiki User
∙ 12y agoAny matter, normal (visible) or dark (invisible), can be noticed by its gravitational attraction. There are several pieces of evidence, all based on the gravitational attraction of some matter that is invisible, but must be there because it has gravitational effects. These include the fact that galaxies rotate way too fast for the amount of known matter, studies on gravitational lensing, and several other pieces of evidence.
Wiki User
∙ 14y agowell i believe that they went in space and took a space radiation picture and then took it back to earth.
I think a more accurate answer is this:
Scientists infer the existence of dark matter from the fact that galaxies would require more matter (mass) than they appear to have, in order to keep from flying apart. From the shapes of spiral arms of galaxies, and the speed of rotation of the galaxies, they estimate how much mass they would require to maintain those shapes.
Well, the mass required is something of the order of 10 times more than the mass they see, so they invented invisible matter: "Dark Matter"
It explains anomalies in their understanding of gravity.
Of course, it could be that there are errors in their understanding of gravity, and that a different theory of gravity could explain the shape of galaxies without having to resort to inventing things that are invisible.
Wiki User
∙ 12y agoThe amount of luminous matter seen in galaxies and in our Universe fails to explain two things:
1) the known distribution of stellar velocities in galaxies.
2) the gravitational distortion of light as it travels through our Universe.
Both of these could be explained by the presence of a type of matter that has gravitational effects but no other type of interaction. In addition, both would be explained by the existence of such matter at the same density level. Because the MOST simple hypothesis explains two VERY different mysteries, most scientists conclude the Dark Matter Hypothesis is most likely the correct one.
Add your answer:
Earn +20 pts
Who discovered dark matter?
Dark matter wasn't "discovered" by any one person or group. In fact it is still hypothetical and there is no solid proof for its existence. Various astronomers inferred the existence of dark matter from what they observed about galaxies and galaxy clusters. It is still very much a mystery and the subject of some serious research.
What do scientists think the sun will explode?
I have never heard that scientists think the sun will explode. I do know they predict that our sun will eventually burn out. But its so far away, it takes billions of years for the dark to reach Earth. So I'm not too worried about the sun blowing up or burning out.
What is King Tut's Last name?
archeologists and scientists don't really know what king tut's last name was or if egyptians even had last names for that matter.
Will there be a big earthquake in LA any time soon?
California sits an a variety of fault lines and it is only a matter of when, not if, a big earthquake will occur. Scientists say it's a certainty. They just don't know the exact time it will happen.
What happened to Patrick Henry when he turned 10?
Historians can not know the answer to that question. No data exists. We do know he was hung by the British.
Is there dark matter inside a black hole?
It is currently unknown as scientists do not even know what dark matter is.
What is dark matter and what exists for it?
We know that dark matter exists because it got gravity, though it is invisible. It hold galaxy and Universe. There is a theory there many other parallel universe outside our universe and dark matter holds those universe up and some scientists says that dark matter are just mass of the matter of the parallel universe. It sounds crazy but that is the Law of Physics. However there is not exact explanation of what dark matter really is, so there are still Noble Prices for those who can come up with a reasonable explanation
How are stars dust and gas similar to dark matter?
The only similarity we know of is that they all seem to interact with gravity. Aside from that, scientists do not know what dark matter is.
How do you know dark matter exists?
In the absolute strictness sense, neither I nor anyone else can know dark matter exists. But we DO know that neither the measured velocities of spinning galaxies nor the bending of light from distant galaxies can be explained (1) by the amount of matter we can see in and between those galaxies (2) with our present understanding of gravity. Either there's some mass out there that we can't see OR we don't understand gravity as well as we think we do. Conceptually, scientists prefer solving these discrepencies with (1), as it means we simply have to add some matter to our Universe. What EVER that extra matter happens to end up being, we will, until we know better, simply call it "dark" matter. Thus, ANY use of solution (1) means dark matter exists, even if we don't know its exact nature. Interestingly, the density of dark matter that would explain the first anamoly -- the spin velocity of galaxies -- is about equal to the density that would explain the second one -- the bending of light through inter-galactic space. This strongly suggests solution (1) for both unresolved problems.
Why can't the so called dark matter be directly observed?
We know that dark matter exists because it got gravity, though it is invisible. It hold galaxy and Universes. There is a theory there many other parallel universe outside our universe and dark matter holds those universe up and some scientists says that dark matter are just mass of the matter of the parallel universe. It sounds crazy but that is the Law of Physics. However there is not exact explanation of what dark matter really is, so there are still Noble Prices for those who can come up with a reasonable explanation.
Is dark matter excreted from black holes?
No. Black holes do not give off anything other than small amounts of Hawking radiation. That note aside, scientists do not know what dark matter is or what its origin is.
Is dark matter Solid liquid or gas?
We do not know as we have not found any dark matter to examine. The only way we detect it and know it exists is due to its gravitational attraction of the ordinary matter we can see. One speculation when neutrinos were discovered to have tiny nonzero masses was that dark matter might be neutrinos. Another speculation is that dark matter is only ordinary matter, but its in another separate universe in a shared higher dimensional spacetime. Nobody knows.
How do you know that matter exists?
If something has mass it is matter.
How long is dark matter been around?
If dark matter exists (the jury's still out on that, but it's looking pretty likely), then ... actually, you know what? We still don't really know, because we don't know exactly what dark matter IS. It may have been around since the beginning of the universe, or it may have formed slightly later. Either way, "around 13 billion years" is a good estimate.
How do you know dark matter is present?
We know "dark matter is present because it affects the world in ways I do not know of.
Is dark matter considered to be the conciousness of GOD?
No. Dark Matter is the cause of a number of galaxies and galaxy clusters apparently having far more mass than they should. Scientists still do not know what dark matter is. It appears to interact with the rest of the universe only through gravity; there is nothing to indicate it has anything to do with consciousness. The idea dark matter relating to consciousness likely comes from Phillip Pullman's fantasy book series His Dark Materials in which dark matter is the stuff of consciousness.
Can dark matter kill you?
The whole point of dark matter ... the thing that makes it "dark" ... is that it doesn't interact with normal matter except through the gravitational force (and, possibly, for some potential types of dark matter ... remember that nobody really knows what it actually is yet ... the weak force).One type of dark matter that we know about for sure is neutrinos. Around 65 billion neutrinos per second pass through every square centimeter of your body perpendicular to the direction of the Sun. They have been since you were born ... since before you were born, in fact. Even at night, because they go straight through the Earth too and come up through the ground on the side facing away from the Sun. The kajillion that have already done so haven't killed you yet, it's not all that likely that the kajillion and first is going to kill you.About the only reasonably possible way to die from dark matter would be if there were a lot of it concentrated in one smallish area, in which case you could be pulled apart by tidal forces if you were in a spaceship that went too close to it. This also isn't likely to happen.
