My Science School

A white hole is a bizarre cosmic object which is intensely bright, and from which matter gushes rather than disappears. In other words, it’s the exact opposite of a black hole. But unlike black holes, there’s no consensus about whether white holes exist, or how they’d be formed.

However, some theorists think that a combination of Einstein’s theory and quantum theory points to a new way of thinking about white holes. Instead of being the ‘exit’ from a wormhole, they may be a slow-motion replay of the formation of the original black hole.

The process starts when an old massive star collapses under its own weight and forms a black hole (see diagram, above). But then, quantum effects occurring around the surface of the black hole halt further collapse to a singularity, and instead begin to gradually turn the black hole into a white hole that’s spewing out the original star matter again. The process is mind-bendingly slow, though, so we may be in for a very long wait to find out if white holes really exist.

Credit : Science Focus

Picture Credit : Google

What you need:

Two balloons, one transparent and one black, A magnifying glass, A sunny day!

What to do:

Blow up the transparent balloon first Hold its mouth so that the air doesn't escape, but don't tie it up.

Now, slowly, insert the un-inflated black balloon into the transparent one. Make sure to keep the mouth of the black balloon out

Once the black balloon is inside, blow it up to about half the size of the transparent balloon. Tie up its mouth and slip it completely into the bigger balloon.

If some air has escaped the clear balloon, puff it up some more and then tie it off.

Go out into the sun and use the magnifying glass to focus the sunlight on the black balloon.

What happens?

 If all goes well, then only the black balloon pops: the outer transparent one doesn't!

Why?

The transparent balloon allows the sunlight focused by the magnifying glass to pass through it (much like a glass window allows light to pass).

But the black balloon absorbs light and converts it into heat. So, the spot where the light falls on the black balloon grows hotter and hotter until it simply ruptures.

Why the black balloon absorbs light has something to do with its colour. Light is made up of seven colours-violet, indigo, blue, green, yellow, orange and red (VIBGYOR). When we look at say a red object, it appears 'red' because it absorbs all other colours and reflects only the red colour back at our eyes. Similarly, a blue object will reflect blue colour and absorb all other colours. But black is the 'absence of colours: so it absorbs all the colours and reflects none back. Since it absorbs light, which is energy, it becomes hot and finally pops.

Picture Credit : Google