Time Dilation Formula / Calculator

An intelligent alien race, living there, will be able to catch you, don't you watch sci-fi movies? The real question is from what you can get 4.13e+19 Jouls, required to reach Alpha Centauri in about 9 years of traveler's time.

Re: Time Dilation Formula / Calculator

#5

Post by tokai » Fri, Jan 10, 2025, 1:01 PM UTC

roter wrote: post #3

How do you stop so you don't go whizzing past Alpha Centauri at near light speed? :)

if you can accelerate at 1g you can also decelerate at 1g

Re: Time Dilation Formula / Calculator

#6

Post by alhadrad » Fri, Jan 10, 2025, 1:02 PM UTC

roter wrote: post #3

How do you stop so you don't go whizzing past Alpha Centauri at near light speed? :)

I was wondering about this too—it's super interesting! Did you create this? Could you add graphs showing acceleration and deceleration? Also, this might be a dumb question, but how does mass factor into the energy calculations? I would love to see graphs that include the multiple stages of travel (acceleration and deceleration) as well as the mass of various kinds of fuel required for different propulsion systems such as chemical rocket, nucular etc.

Re: Time Dilation Formula / Calculator

#7

Post by jvanderbot » Fri, Jan 10, 2025, 1:02 PM UTC

Tangential, but I want to share the thought experiment that made time dilation click for me.

We know everything (every effect, etc) has a speed-of-light limit.

Imagine a metronome ticking out time. It ticks back and forth.

Put the metronome on a space ship. Now slowly increase the velocity of the space ship. As the space ship speed increases, the "pendulum" weight now has more and more velocity (the space ships velocity plus the back-and-forth velocity). The sum of those velocities cannot exceed the speed of light, so as the spaceship velocity increases, the metronome will tick more slowly (||x+y||c, right?), until, asymptotically, the metronome cannot move along its pendulum swing b/c the spaceship is moving at c.

(The metronome is a proxy for every chemical and physical process going on with you / your spaceship - they electro-chem-quantum-etc tick out their normal evolution, which must cease at c)

It's a clockwork view of the universe that might not be strictly true, but it settles some cognitive dissonance so I'm clinging to it like a life raft.

Re: Time Dilation Formula / Calculator

#8

Post by 09thn34v » Fri, Jan 10, 2025, 1:08 PM UTC

jvanderbot wrote: post #7

Tangential, but I want to share the thought experiment that made time dilation click for me. We know everything (every effect, etc) has a speed-of-light limit. Imagine a metronome ticking out time. It ticks back and forth. Put the metronome on a space ship. Now slowly increase the velocity of the space ship. As the space ship speed increases, the "pendulum" weight now has more and more velocity (the space ships veloc…

interesting thought experiment... am i correct in understanding that for this to apply, the pendulums plane of movement must not be perpendicular to that of the ship itself? additionally, when the pendulum swing's direction is in the opposite direction of the ship, it would still move even in the case where the ship is moving at c, correct?

Re: Time Dilation Formula / Calculator

#9

Post by jvanderbot » Fri, Jan 10, 2025, 1:14 PM UTC

09thn34v wrote: post #8

jvanderbot wrote: post #7

Tangential, but I want to share the thought experiment that made time dilation click for me. We know everything (every effect, etc) has a speed-of-light limit. Imagine a metronome ticking out time. It ticks back and forth. Put the metronome on a space ship. Now slowly increase the velocity of the space ship. As the space ship speed increases, the "pendulum" weight now has more and more velocity (the space ships veloc…

interesting thought experiment... am i correct in understanding that for this to apply, the pendulums plane of movement must not be perpendicular to that of the ship itself? additionally, when the pendulum swing's direction is in the opposite direction of the ship, it would still move even in the case where the ship is moving at c, correct?

That's the way I think of it, yes, but I think it generalizes - during the backward swing it would "go", but when swinging toward the front of the ship it would "stop" - forever.

Re: Time Dilation Formula / Calculator

#10

Post by rolftheperson » Fri, Jan 10, 2025, 1:16 PM UTC

jvanderbot wrote: post #7

Tangential, but I want to share the thought experiment that made time dilation click for me. We know everything (every effect, etc) has a speed-of-light limit. Imagine a metronome ticking out time. It ticks back and forth. Put the metronome on a space ship. Now slowly increase the velocity of the space ship. As the space ship speed increases, the "pendulum" weight now has more and more velocity (the space ships veloc…

This is not correct, I urge you to read a bit about Lorentz invariance, once you understand you will see why your statement does not make sense given special relativity is accurate.

Lorentz invariance means the laws of physics remain the same in all inertial reference frames. Also a spaceship going 99.9999…% the speed of light.

This leads to effects like time dilation, length contraction and the speed of light itself.

The metronome can keep going at any speed independent on the speed of its own reference frame.