Exactly as its name suggests, black holes are black. You can not see them directly. If a black hole is isolated then there is no other large object in its near vicinity. We would be able to see the other large object and notice that it is wobbling instead of remaining perfectly still. This is an obvious indication that there is a dark object for the other large object to orbit around. The next step is to see if that dark object is a neutron star or a black hole.
Another way to identify black holes is to check for high energy radiation. This is caused by particles on the horizon of a black hole that has reacted with other particles and released this energy. It is very difficult to find this sort of energy by scanning the sky with a telescope, but more importantly, if the black hole is isolated, then there is very little chance that there is enough particles on the horizon to react and release the high energy.
Not only is it difficult to detect isolated black holes, but it is difficult to understand how they could be formed.
No, not in the sense usually thought of when the word rip is used... there are no ragged edges. But it does produce an isolated area of spacetime from which nothing can return.
We do not know of any planets that have been destroyed by a black hole, but it probably has happened. Because of the vast distances in space and the fact that neither planets nor black holes emit light, both are hard to detect.
Black holes can technically be any where. Some scientists believe that there is a black hole in the center of our galaxy along with many other galaxies. Because black holes are so difficult to detect, they can be very dangerous.
Since you can't see a black hole, scientists use a method called gravitational lensing to detect black holes. Since black holes warp space-time, the light that travels near a black hole is bent, like how a magnifying glass warps the object a little at the edges. Scientists look for unusual distortions of light caused by this effect to look for black holes.
A radio telescope
Black holes do exist - they are just VERY difficult to detect.
Because the astronomers can detect that a star is being whirled around in space, or space is being distorted.
An astronaut in outer space
No, not in the sense usually thought of when the word rip is used... there are no ragged edges. But it does produce an isolated area of spacetime from which nothing can return.
1. The factors that contribute to the differences in appearance of isolated vs crowed colonies are: 1. Availability of nutrients, where colonies are crowed the bacteria will be in competition for nutrients and because of this there can be a reduction of size and shape also growth can also be stunted whereas in isolated colonies the nutrients is readily available with no competition for nutrients. 2. space, isolated colonies have more space to grow as compared to crowded colonies and 3. If there is contamination in a crowded colony the texture will be very difficult to determine however texture can be viewed in isolated colonies so contamination is a factor.
An astronaut in outer space
The chances are pretty low because it doesn't matter on the size to detect gravity.
If the size of the space station is large enough, then the astronaut will detect the change in Earth's gravity (g).
We do not know of any planets that have been destroyed by a black hole, but it probably has happened. Because of the vast distances in space and the fact that neither planets nor black holes emit light, both are hard to detect.
A radio telescope.
radar
RADAR