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MathematicalPhysicist
Aug12-03, 08:39 AM
what is the maths of this paradox?
or more precisely how do you compute the age of the man who stays in earth while the other one in the spacecraft has spent a year in the vehicle?

thanks in advance.

Janus
Aug12-03, 11:42 AM
Originally posted by loop quantum gravity
what is the maths of this paradox?
or more precisely how do you compute the age of the man who stays in earth while the other one in the spacecraft has spent a year in the vehicle?

thanks in advance.

For the unaccelerated parts of the trip, you use

T0 = t1/[squ](1-vē/cē)

For those parts where the spacecraft is undergoing acceleration, you use

T0 = c/a * sinh(at1/c)

To find v after time t1 at acceleration a:

v = c * tanh(at/c)

MathematicalPhysicist
Aug13-03, 09:57 AM
Originally posted by Janus
For the unaccelerated parts of the trip, you use

T0 = t1/[squ](1-vē/cē)

For those parts where the spacecraft is undergoing acceleration, you use

T0 = c/a * sinh(at1/c)

To find v after time t1 at acceleration a:

v = c * tanh(at/c)
does t0 for the person in earth?

Janus
Aug13-03, 10:09 AM
Originally posted by loop quantum gravity
does t0 for the person in earth?

Yes.