Uhm, no? He's talking about a constant speed of 1 LY/s, and not an acceleration.

And what he said was nonsense; 10 LY/s is faster than light; you must be a hypothetical particle with some crazy properties and our math really breaks down at that point.

In space you need to think in terms of relative velocities less than c and acceleration. To get a reasonable sense of how far away Andromeda is consider how long it will take to get there, which is just a few years.

Are you talking about the Andromeda Galaxy? The one that is 2,500,000 light years away? At a constant 10 light years per second speed, that's 69 hours.

Also, even ignoring relativistic effects, it would take a very long time to get there at 1g acceleration.

d = a * t² / 2

2.3652e22 meters = 9.80665 m/s² * t² / 2

4.7304e22 meters = 9.80665 m/s² * t²

4.8237e21 s² = t²

6.9453e10 seconds = t

That's about 2200 years, not 28.

Why would you ignore relativistic effects?

Try entering the numbers here: http://nathangeffen.webfactional.com/spacetravel/spacetravel...

I think that taking traveler time instead of observer time when the discussion is scale of the universe isn't what people would expect. But I do agree that ignoring the relativity here is silly -- of course it makes the observer time close to the 2.5 million years you would expect given its distance.

And thanks for the site. Do you know whether it takes into account deceleration? Because getting to Andromeda at .99c isn't going to do much good unless you're heading somewhere else...

> Do you know whether it takes into account deceleration?

Looks like it does. If I plug in a distance of 980m and acceleration of 9.8m/s^2, it gives a 20s time. That's 10s of acceleration (0.5 * 9.8 * 100 == 490m traveled) and 10s of deceleration.