If gravity was reduced by half on the earth what would happen?

Answer 1

First, it depends how it happens.

If you were to just make the Earth have half as much gravity (by reducing its density, presumably), the Moon would fly away into interplanetary space (leaving us with no tides) and many life forms would die almost immediately (because the density of the atmosphere and the the pressure of both the atmosphere and the ocean would decrease). There would also suddenly be an enormous number of vehicle and aircraft crashes due to the sudden change in gravity and the thinner atmosphere. The thinner atmosphere may also cause the Earth to cool down, although I'm not so sure about that. The International Space Station would move to a higher orbit, but would probably be accessible (and the interesting thing is, the people inside wouldn't even notice any particular change until they saw the Earth flying away from them! :P).

If the force of gravity was reduced by half across the Universe, then the Sun would probably explode, the Earth (and all the other planets) would fly away from the Sun and, again, the Moon would fly away from the Earth. The galaxy would also start to fly apart, but so slowly that we wouldn't notice it for some time. Over the next few thousand years we (provided we still existed after the disaster) would also see a number of x-ray flashes with our radio telescopes as varius black holes and neutron stars across the galaxy exploded.

I don't think we want either to happen right at the moment.

Answer 2

That would be neat! Airplanes could carry much greater payloads, all kinds of structures, like bridges and towers, could be built more easily and with lighter materials. People could jump higher and fall farther without getting hurt. Landslides and avalanches would be less likely to happen.

But I suppose there could be bad effects too. Ocean waves could be higher. The air might get thinner because gravity would not be compressing it as much. That would negate that airplane advantage and also allow the top of the atmosphere be higher in space, so that the space station would not be high enough to stay in orbit. Less gravity would probably mess up all kinds of natural balances in the ecosystem too, but I don't have an exact idea what that might be like.

Answer 3

Depends on what caused the reduction.
If it's the result of another body hitting us and taking half the mass in the process, what would happen is totally immaterial. There wouldn't be anyone left to be concerned with it.
If it disappeared magically, whooosh, you would have to relearn anything physical.
The atmosphere would expand and thin out, but stay! (Venus with the same size as the earth, maintains a 90 atmosphere pressure gas envelope).

Answer 4

The air pressure felt by everyone would be reduced 1/2 and most organisms could not survive under that condition due to the change of volume (and liquid/gaseous state of some) of gases within and outside our bodies (kind of like the nitrogen decompression or "bends" experienced by divers).

A reduction in density of the atmosphere would probably yeild an immediate shift in temp. (i.e. PV=NRT assuming local volume is constant)

Would the planet lose some atmosphere? - probably
Would weather patterns change? - definately
Would solar radiation be worse due to the thinning of the atmosphere? - mostlikely

Answer 5

Lots and lots of bad stuff. For openers, most of the atmosphere (which is held in place by gravity) would diffuse off into space and you'd die.


Doug

Answer 6

you would weigh half of your weight now

Answer 7

all the aliens would feel right at home...

Answer 8

we would float in the air and dift off somewhere...............