Shirish Katkar's Key Ideas from Brief Answers to the Big Questions
by Stephen Hawking

A black hole is a region where gravity is so strong that light cannot escape itself.

A black hole has a boundary called the event horizon. It is where gravity is just strong enough to track light back and prevent it from escaping. Because nothing can travel faster than light, everything else will get dragged back also. 

It is much more likely to emit radiation. A mountain sized black hole would give of X-rays and gamma rays, at about 10 million megawatts, enough for world's electricity supply.

The last asteroid collision with us was about 66 million years ago and that is thought to have killed the dinosaurs, and it will happen again. It is guaranteed by the laws of physics and probability.

There are other problems like rising temperature, reduction of polar ice caps,deforestation overpopulation disease war human lack of water and decimation of animal species. If these problems keep growing human life would be unsustainable. 

The earth is becoming too small for us.

Not to leave planet Earth would be like castaways on the desert Island not trying to escape. We need to explore the solar system to find out where you humans could live.

It won't solve any of our immediate problems on the planet Earth but it will give us new perspective on them and causes to look out words rather than inwards. 

The technology is almost within our grasp. It is time to explore other solar systems.

Hopefully, it will unite to face the common challenge

The future will depend more on science & technology than any previous generation's has done. People need to know about science more than any before them because it is a part of their daily lives in an unprecedented way.

We have to make sure this generation have not just the opportunity but the wish to engage fully with the study of science at an early level so that they can go on to fulfil their potential and create a better world.