Accceleration

Using only classical physics and ignoring other variables such as terminal velocity, non-uniform g, the equation would be a=v/t. Rearranging the equation would give you a/v=t. If you set v equal to c (~3.00*10^8 m/s^2) and your acceleration to g (9.81 or 10 m/s), you'll find the time in seconds.

Note that the closer one approaches the speed of light, time and distance shifts and this classical equation is no longer valid.

oops, I meant v/a=t :P

That would make it almost a whole year of free falling. Might get a little hungry along the way. Better take some snacks with you.

forever

No - it's been done ! - viz:

There was a young lady named Bright

Whose speed was much greater than light

She set out one day, in a relative way

And returned on the previous night

1 year and 17 days 18 hrs 40 minutes or there abouts. In Canada thats 4596 beers per person!!!! Might need more chips and hockey sticks.

lynlynch is correct, because of the distortion of Space-time theoretically you will never achieve the speed of light.

If time is measured in the same frame of reference as the acceleration is measured, it will take c/ gn seconds [somewhat under a year; taking the "standard value for gn (=9.80665 m/s²) that would be about 353 days, 19 hours and 45 minutes]. The main reason that this can never happen depends on what frame of reference you select.

If the acceleration is relative to an inertial frame, the impossible bit is that both the force and the power that would be needed to maintain that acceleration increase towards infinity as the object approaches the speed of light.

If the acceleration is in the frame of reference of the object, there is an additional reason - time dilation means that the acceleration relative to any inertial frame tends towards zero as the speed approaches that of light.

If you get on the rocket and start accelerating at 1g, people back home will think that you have reached light speed when you think that it's been roughly about a year since launch.

Sure, everybody back home will be long dead by then, but you'll still need only one year's supplies of chips...

Rule of thumb, so that you never get confused by relativity again: It only sucks for those left behind!

Hang on a mo'. They'll think that you have reached light speed i.e. one Earth year later while you are still accelerating due to time expansion. When you do reach light speed they'll be long dead as you say, but you'll think its only a year - right ?

It all depends on the frame of reference you choose for defining the acceleration - if you choose the Earth, people on Earth will see it as taking just under a year, if you choose the object, a theoretical observer on the object would register just under a year.

For the first case, the clock on the object will naturally register somewhat less than the Earthbound clock (no, I haven't done the sums). During the course of the journey, the acceleration in the object's frame of reference will rise from 1-g to infinity.
For the second case, a theoretical observer on the Earth would see the acceleration as taking infinite time. It would also see the acceleration as starting at gn and gradually falling as the object gets faster.

An oddity: as the object is always stationary in its current frame of reference, in that frame the accelerating force will never be seen to do any work - though modelling at any time would show that the force has been absorbing energy in the past and will be expending it in the future. Which raises the question - for the second case, will the Earthbound observer see the power expended in accelerating the object as increasing or decreasing with time?

The best brain on CR4 for this sort of thing is 'Jorrie'.

Haven't seen Jorrie in a LONG LONG time. Is he still with us?

Bill

You bet!