• Question: How long could we survive without gravity?

    Asked by the waffle man to Alice, Bose, Christian, Emma, Steve on 16 Mar 2016.
    • Photo: Steve Marsden

      Steve Marsden answered on 16 Mar 2016:

      Not very long at all.

      Ok, so humans are no longer tethered to the planet. No big deal if you’re indoors. You’ll just bounce around a bit. If you’re unlucky enough to be outside, then you’d generally head to the upper atmosphere, being thrown out by the Earth’s rotation. Assuming that you weren’t wearing arctic clothing, you’ll probably freeze before you get too high to breath. I’d give you tens of minutes minutes.

      … Except that the air isn’t being held to the Earth either. The air will fly off in all directions into space. You’d suffocate and loose consciousness within a minute. You’d be dead a couple of minutes after that.

      … Except, the Earth is being held together by gravity. The incredibly high pressures inside the Earth lead to a huge amount of heat. Really the planet is like a giant spring that’s been compressed by gravity. Turn off gravity and the Earth is going to expand… explosively. Throwing molten iron and rock in all directions. You’d be killed within a fraction of a second, before whatever bits of you remain are thrown into space to freeze.

      … Also, has the gravity in the sun been turned off as well? In that case the sun would explode in a supernova. The explosion would travel close to the speed of light. It would take about seven minutes for the shock wave to reach the Earth, at which point it would obliterate the frozen lifeless remains of you. Not only ripping you atom from atom, but ripping the atoms apart themselves.