• Question: why does gravity exist?

    Asked by irontitanium to Joe, Jos, Kate, Lisa, Pierre on 12 Nov 2014.
    • Photo: Kate Dobson

      Kate Dobson answered on 12 Nov 2014:

      I’m not up to speed with the latest research in this field, but Isaac Newton worked out the law of gravitation that says that every object exerts a force of attraction on every other object. This is gravity, and how strong it is depends on the mass of the two objects and how far apart they are. If you what know know more about space and time and other complicated science I would read the books by Russell Stannard: The Time and Space of Uncle Albert, Black Holes and Uncle Albert, and Uncle Albert and the Quantum Quest. I read these book when I was about your age and they made it all really exciting. It was one of the reasons I stuck with physics even when I found it hard.

    • Photo: Joshaniel Cooper

      Joshaniel Cooper answered on 12 Nov 2014:

      Gravity, in many ways doesn’t exist! Einstein worked out that what really happens is that things which are heavy (like the earth or sun or even you a little bit) bend space around them. You can imagine this like if you sat on a trampoline you will bend the top of the trampoline and a ball on the edge of it would roll towards you. This is the same effect that the bending of space has. So you see heavy things being attracted to eachother (like you to the earth), and this is just what gravity looks like!

Comments