• Question: how does gravity work

    Asked by abigail to Peter on 11 Nov 2021.
    • Photo: Peter Milner

      Peter Milner answered on 11 Nov 2021:

      This isn’t really my area of expertise of I’ll give it my best shot! Gravity is one of the fundamental forces in the universe. It is in the direction towards the centre of the earth, which is why wherever you stand on earth, you will be pulled downwards. The rate at which this force accelerates is a very important number in physics: 9.8 m/s^2. We can use this value to help figure out how fast things will fall in the air, and if you multiply this number by your mass in kg then you will find the force that you exert where you stand. Gravity gets weaker as you get higher off the ground though, and eventually will be 0 (in space).

      When it’s 0, there’s no force pulling you down, so you float. We can recreate this feeling on earth if you accelerate towards the earth at 9.8 m/s^2, and you basically cancel out the force of gravity and you essentially float!! You can go on special airplanes that do this (fly towards the earth really fast) and feel like there’s no gravity!

      As for the source of gravity, well that’s what you could become a scientist for, to research that, because I don’t even fully understand that! It’s quite a complicated topic…

Comments

  • Photo: Pawel

    Pawel commented on :

    Hmm, I tell you a secret, nobody really knows, we only know that it effects can be experienced and scientists cannot even agree it gravity exists at all or it is just some other phenomenon that makes us feel as if gravity really existed! you can read more here: https://www.nytimes.com/2010/07/13/science/13gravity.html
    One needs to remember that there is very few things in the Universe that are absolutely true or can be interpreted in only one way. This should not stop us from trying to describe the Universe. For most application and daily life it is ok to say that gravity exists and it is caused by interaction of the mass with space time. you can actually understand a lot about gravity with the following experiment: https://www.youtube.com/watch?v=cHySqQtb-rk