• Question: whats space like

    Asked by louis12345678910111213141 to Andrew on 23 Jun 2015.
    • Photo: Andrew Fensham-Smith

      Andrew Fensham-Smith answered on 23 Jun 2015:

      BIG! Space is really big. Like, really really big. It’s impossible to fathom how big it is. You know the ocean? It’s way bigger than that. If millions and billions and trillions of times bigger than it. I can’t comprehend it. There are one hundred billion galaxies in the universe, and each is separated by millions and billions of light years. A light year is unimaginably big too – light travels 200,000 miles a second, it can go to the moon and back in under two seconds. So a light minute is 30 times the distance between the moon and our planet. It takes eight minutes for light to travel from the sun to our planet. Stuff is really far apart.

      The other thing is there is actually very little in space. You could drive in a direction at the speed of light forever, and you almost certainly wouldn’t hit anything, ever. You would get to the edge of the universe and you wouldn’t have hit anything. You get out into space, and there’s nothing.

      Space is also pretty cold – it’s -290 celsius there a lot of the time, and the pressure is so low that if you were teleported there now your saliva and tears would immediately boil from your mouth and eyes, and all the oxygen in your lungs would be sucked out. You would get cold, but not because there is a stiff breeze – your body would just radiate out the heat and it wouldn’t come back. Like sitting next to a cold wall – it’s not sucking heat out of you, you’re radiating heat to it!

      There’s also a lot we don’t understand – like what is it made of? We have equations we use to understand gravity and how fast galaxies should be spinning but when we use them, and add up how much matter is in those galaxies, we see they are spinning too quickly. Either our equations are wrong, or these galaxies are made of stuff we can’t see. Some scientists call this stuff something called a WIMP – weakly interacting massive particles. They call them that because they don’t interact with matter in any way, except by the gravitational force. It’s a bit of a fudge but people seem to think that it’s a good idea!

      Hope this helps.