Tria & The Speed of Light

For my own benefit (and for the sequel I'm working on for "Pastor"), I was trying to figure out the math of the Stargate: Atlantis episode "The Return, Part 1," in which they discover a crew of Ancients on the good ship Tria, hurtling at 0.999 the speed of light between the Pegasus galaxy and the Milky Way.

And it doesn't add up.

Here's why:

We know the Pegasus Galaxy and the Milky Way are 3 million lightyears apart (which is true, if we consider the Pegasus Galaxy to be the Pegasus Dwarf Irregular Galaxy, as evidence seems to suggest, rather than the Pegasus Dwarf Spheroid Galaxy, which is only 2.7 million lightyears away). So, something travelling at lightspeed will take 3 million years to get from one to the other. And that's a long time, even for Ancients.

Anyway, in the episode, the Tria's hyperdrive fails at about halfway, so they ramp up their subspace engines to 0.999 the speed of light and expect to make it to the Milky Way in their lifetimes, or something. Now, granted, near lightspeed is fast, but any journey of 3 million lightyears will take more than 3 million years if you're traveling at sublight speeds. Granted, time dialation comes into effect, so it won't seem light 3 million years, but still. It's a long time. For compairson, if you're travelling at 0.9 the speed of light, then:
 Real Time Ship Time
 1 Day (24 Hours)10.56 Hours
2.29 Years (837.31 Days) 1 Year (365 Days)
 2,294 Years 
 3 Million Years1.32 Million Years

Or, basically, you percieve time at 44% real time. So, if you're going at 0.999 the speed of light, like the Tria, then:

Real Time Ship Time
1 Day (24 Hours)1.07 Hours 
22.37 Years (8,165.05 Days)1 Year (365 Days)
22,366 Years 1,000 Years
 3 Million Years134,132 Years

So you're experiencing time at 4.47% real time. But, still, even if your hyperdrive died halfway into the journey, than you're never going to make it to your destination in your lifetime. [Space Math]

Unless you've stasis pods. Other SGA episodes have already determined that Ancient tech can hold you stasis, so you age at about 0.5% the normal speed, so that:

 Stasis TimeReal Time
 0.12 Days (2.88 Hours) 1 Day (24 Hours)
0.005 Years (1.83 Days) 1 Year (365 Days)
 1 Year (365 Days)200 Years (73,000 Days)
  50 Years10,000 Years

What all of this adds up to is, if you get into a stasis pod much after your 30th birthday, you can stay in stasis for about 10,000 years real time before you start having problems, like being too old to enjoy the destination after you get there, or, well, dying while in stasis. [SGA: "Before I Sleep," Aurora;" SG-1: "Lost City, Part 2"]

But combine 0.5% stasis with 0.999 lightspeed and you start getting places.

 Stasis TimeShip Time Real Time
 1.96 Hours16.31 Days 1 Year
 1.83 Days1 Year  22.37 Years
 2.235 Years 447 Years10,000 Years
 670 Years 134,132 Years  3 Million Years

So, granted, if you put yourself in stasis halfway along a 3 mililion year journey, you can live a lot longer than you would otherwise. But, unless the Ancients lived a lot longer than we know, it doesn't do them any good putting themselves in stasis, because they'll still have aged 335 years by the time they got to the Milky Way. Which does no one any good. Especially as they're in stasis and not making little Ancient babies, who could have Ancient babies of their own, and so on, until the original crew's descendants reached the right galaxy.

So, that whole plot goes right out the window, but, just for my own fun, I did the calculations to figure out at what ratio they'd have to be in to reach the Milky Way in, oh, say about 20 years elapsed stasis time. Well, 21.46 years to be exact, but it comes out to a 0.016% dilation, where you'd age at about 1/6250th the normal rate of speed. On a ship going at 0.999 the speed of light.

Presumably, if the Ancient's had had the tech, they would have used it. But, otherwise, there's a plot-hole large enough to drive an Aurora-class battlecruiser through. Stil, both parts of "The Return" are some of my favourite SGA episodes, so, not really complaining. Just pointing things out.
  • Current Mood: confused
  • Current Music: Heather Nova "Blood of Me"
Math is a bad subject for me, I'm afraid. So while I couldn't follow your numbers, I definitely got the gist of what you were saying.

But I suppose we don't really watch for the accuracy :\
it all adds up to the fact that there's no way the crew of the Tria could ahve hoped to make it to Earth in their lifetimes, unless they had 1) significantly better stasis chambers than we've otherwise seen or 2) could expect to live four hundred years or more in a normal lifetime.

and, yeah. it's annoying, but what can you do?
Is there evidence saying that the Alterans had a lifetime similar to ours? I've only seen SGA, and I don't recall the show saying one way or another. Does SG-1 explore this?
it doesn't. But I've nominally decided they had twice the lifespan, thus allowing Iohannes' greatgrandmother to have done the original flying-to-Pegasus-from-Earth.

IDK, it seems to only make sense that they'd live longer than we do. But I really like your take on everything!