Has any one seen a cosmological Black hole? they are the most extreme entity in the universe but, apart from gr maths, what is the evidence for there existence?
Most cosmologists refer to black holes as 'compact objects'. They cannot see these objects directly, but can see their effects on stars and other objects in the region of space. For instance, astronomers can plot the path of whole stars as they are whipped around the compact object at tremendous velocities and calculate the huge mass of these invisible compact objects. When you can see the individual stars, but not the compact object that has billions of times the mass of the star, a black hole is the only term that seems to fill the bill. The object is exremely massive, but doesn't show up in our telescopes whereas the much less massive nearby stars do. The exact nature of the black hole is open to debate, for instance if there is a true singularity in its center, or if our model just breaks down at those gravitational extremes.
I think the black hole theory, is the limit of modern science/crackpotery, the emergence of worm holes, time travel, is a blot on rational thinking, it would be an advantage to eliminate them.
Can you imagine the singularity? It is the realm of non science, or maybe you have visited your great great grandad? or traveled to the future.
Worm holes and time travel are not in the same class as Black Holes. There is good reason to believe in the existence of Black Holes, but not much, If any, reason to believe in worm holes & time travel. BTW: Even those who accept the existence of Black holes do not really accept the notion of a singularity. The prediction of the singularity is generally viewed as a reason to believe that the equations are no longer applicable at some distance from the center of a Black Hole. Note that classical gravitational equations similarly fail to describe what is happening for certain extreme situations, but are still used for many purposes (EG: Most of the NASA space program projects).
Ask yourself, If you apply, the faster the rotation, the lower the density around the equator. Would it be a disk(black hole)? Personal mathematical opinion-NOPlease Register or Log in to view the hidden image!
Due to our reliance on light in order to see anything, it is utterly impossible to actually see a black hole, as their immense gravitational pull swallows all light. But we are able to witness the bending of light which evidences them. But because of their nature, it is unlikely that we will ever actually know the true nature of what we call a black hole.
We have seen hard evidence of a black hole near the center of our galaxy. You can't see it directly, but the orbits of several nearby stars make a sharp arc around it in a way that reveals it's extraordinarily massive nature.
Yes, even though I don't have to. A black hole is an object so dense that the escape velocity at its surface exceeds the speed of light. Infinite density is not required, and the idea that such an object could exist predates general relativity. You're not very convincing. No. Therefore?
The existence of black holes is pretty much the consensus of the modern Physics community. There is very little (if any) argument that such objects do not exist. The nature of the "center" of a black hole is debateable, and for practical purposes more of an excercise. It's not like building a bridge - everyone knows it's useful and nobody complains about it - it's more in the realm of the kind of stuff geeks have a good time working out. Is that so wrong? And Hawking has basically disproved the carniverous black hole concept wherein a black hole grows and grows indefinitely until (inevitably) all the matter and energy in the universe is sucked in never to be seen again. Hawking Radiation as it is called actually leads to the eventual decay of all black holes and with it the disappearance or elimination of the event horizon. The fate of all matter is likely relatively even distribution throughout the universe. Right now our cosmic neighborhood is decidedly "clumpy." The biggest clumps are black holes. Period.
