Black Holes?

Question

I read somewhere that black holes have such strong gravity that it even "sucks" in light, thats why it's called a black hole, and therefore they are basically invisible. So if we can't see them and obviously can't go near them, how did scientists find them or know about how they work.

Answer 1

Black holes are not visible directly. But their gravitational effects are visible. Also, light produced just outside of their sphere of inescapability, the so-called Shwartzschild radius, is visible.

We sometimes see a black hole's effect on a neighboring star that is visible, such as when it attracts gas from the neighbor that causes a burst of radiation at the black hole (a nova)

Sometimes a black hole is inferred by its ability to bend light grazing by it creating a so-called gravitational lens, which causes the same object to appear to be several objects all around the region where the object actually is

The supermassive black holes in the Milky Way and in Andromeda were discovered by the extremely rapid movement of orbiting stars with extreme red and blue shifts as they speed away and then come back around toward us.

Relatively young galaxies from the early universe with central supermassive black holes produce quasars, the most powerful blasts in the universe after the Big Bang itself, which are extremely bright. Because they are ancient, they appear only at extreme distances, like nine billion light years away.

All of these are manifestations of black holes and provide indirect evidence of their presence.

Answer 2

A black hole is an elegant theoretical entity,which likely does not exist.
It is a mathematical equation.
If it could exist it would be a 2 to 3 solar mass sphere about 3 km in diameter whose surface gravity was such the escape velocity from it's surface would be greater than the speed of light,so it would be invisible.
It would act like any other celestial body but it would be black.

Answer 3

They combine right into a single black hollow. the two black holes combine to make the "new" black hollow, this is a mixture of the two. Their adventure horizons fuse. particular, the consequence of two black holes colliding is a much better black hollow. The radius of the recent black hollow is approximately the sum of the radii of the two unique black holes. yet black holes are enormously small---even a black hollow that has eaten an entire galaxy is smaller than the image voltaic gadget. If the Universe keeps to enhance (as is estimated), then there is not any way that the completed quantity of the Universe could desire to be taken up by using black holes.

Answer 4

Black holes are identifiable by specifically their nature of preventing anything that enters them from escaping. Black holes consist of a singularity of exceedingly dense matter with an immensely strong gravitational pull. In the realm of rlativity, this singularity is where the curvature of spacetime approaches infinitude. When matter (including light, which consists of photons, which are both particles and waves) crosses what is known as the event horizon of these black holes, it is "sucked in" and absorbed by the singularity. Most importantly, the lack of light and matter visible in these regions, and of radiation in the area, is what alerts scientists to the presence of a black hole. Matter and radiation are everywhere, and radiowaves can be rebounded off of them to give scientists an accurate perspective of the shape of the universe.

Answer 5

It is because of the huge gravity ,in fact it is so strong that solar systems are in orbit around them . The gravity well may be 100 light years across.

Answer 6

The existence of black holes was first theoretically predicted by astrophysicists and later confirmed by the emission of light by matter accelerated to very high velocities as it is pulled towards the black hole.

Answer 7

They look at near by stars and watch how they act. Then they can calculate about where the Black hole is. Thats kind of like. at night, when your looking for that black ho and can't see her. Just watch the men standing around her and you can guess about where she is.

Answer 8

its all about theory ofmatter in the universe, they need to go practically and watch them

Answer 9

Actually... Black holes are not that invisible...As I know they were
extincted stars....http://images.google.com.ph/images?client=firefox-a&rls=org.mozilla:en-US:official&channel=s&hl=tl&q=Black%20holes&oe=UTF-8&um=1&ie=UTF-8&sa=N&tab=wi
So, I think the scientists trace it via microscope...

Answer 10

It's a mystery my child.