Freda Moonbeam, of Tui community, Takaka, asks :-

Kelly Twohill, of Queenspark School asked:-

What would happen if you fell into a black hole?

Frank Andrews, an astronomer at Wellington's Carter Observatory, responded.

Black holes are places where gravity has been able to collapse a star or centre of a galaxy into an unimaginably tiny volume. Their gravity is so strong that not even light can escape from it. Hence we can detect black holes only when matter falls into them. The matter becomes so compressed that it gets hot enough (billions even trillions of degrees) to give off huge amounts of light and even X-rays and gamma-rays.

They are weird in that near a black hole gravity is so high that Einstein's general theory of relativity applies. Because we dont see effects of this theory in everyday life its predicted effects often seem to go against common sense. Near a black hole space and time are distorted. For each one there is a point of no return, an event horizon, beyond which space and time have no meaning and not even light can escape.

If you could watch someone falling into a black hole you would never see them reach the event horizon. This is because time slows and eventually stops at an event horizon. The person would seem to be going slower and slower, and at the same time getting redder and redder and fainter and fainter till they faded away completely just above the event horizon.

If you fell feet first into a black hole you would not notice any change in the speed of your clock. What you would notice, as you approached the event horizon, is that your feet were getting much heavier faster than your head. In effect you would be getting stretched out like spaghetti. The gravitational forces near an event horizon are so enormous that any object, even atoms, would be torn to pieces.

As you were being torn apart you might notice that clocks far away from the black hole appeared to be speeding up relative to your clock. As you looked out into space you would see the future flashing past while time passed normally on your clock. Unfortunately it wouldn't do you any good even if you saw next week's Lotto numbers, because you couldn't get out to buy a ticket and you couldn't get a message out either, as even light cannot escape.

There is still a lot to learn about black holes. There are many challenges left for you youngsters to investigate and solve.