# G-Force in space

1. Feb 8, 2006

### teken894

I've been pondering this in my tiny mind for a couple of minutes, but I can't figure it out..

1. Can a person experience G-Forces in space? so...if i'm accelerating in space, do i feel a g-force? SO...if we do feel g-forces, then even if technology allowed for (say .5c ) travel, it might take years to accelrate to/decelerate from that speed as the our bodies can't take the forces of the acceleration??

2. Also...another random question...why is the speed of light 3e8 m/s? i get the GR and stuff ...but is there any comprehensible explanaiton (if there is one) of why the speed of light is at that speed? why not 4e8 m/s or greater...WHy is light itself limited to that speed?

I don't mean why can't we travel faster than 3e8, i want to know why light travels at that speed? why is it that photons can only achieve the speed of 3e8 m/s.

IM a HS student thats curious

2. Feb 8, 2006

### stunner5000pt

lets say you were in a stationary bus (sitting, standing). When the bus starts moving do you feel a 'force' pushing you back against the direction of motion?
Now in space there is no significant gravity to pull you down. So when the ship were to start accelerating you would feel teh same as you would on a bus.

im not well experienced in this and i may be wrong on this but i know that the speed of light depends on 2 constants
$$C = \frac{1}{\sqrt{\mu_{0}\epsilon_{0}}}$$
mu0 being the permeability
epsilon0 be the permittivity of free space
they are measured values, measured from experiments. Even when Einsten made his theory of relativity he made the assumption (postulate) taht the speed of light is constant but we dont know as of yet is tahts true or not.

3. Feb 9, 2006

### tony873004

Even if there was, you wouldn't feel it since it would pull you and your spaceship equally.

The astronauts on the shuttle experience gravity that is about 90% that of the surface of Earth. Yet they are in a weightless environment.