 |
| |
|
|
Last Conformist
|
 |
of Calakmul
Jul 2003
time: 06:37
|
|
I don't see why travel times is such an issue.
Imagine that some alien planet sends out a spaceship that needs a million years to reach the next star. Once there, it establishes an outpost, and builds a new ship. The mother planet does likewise (after watching reruns of Family Guy for a million years). In a further million years, these two ships arrive at two new systems. Repeat.
In less than eighteen million years, there'll be an outpost at every star in the galaxy (except for some recently formed stars, and a few that will have gone supernova and blasted it's associated outpost to bits, but that's marginal).
Eighteen million years is, of course, well little on the galactic timescale. And this assuming pretty slow interstellar travel - in a million years, Voyager 1 will have reached 50-60 ly out, or some ten times the average distance between stars in this part of the galaxy.
So, if even one civilization in the galaxy has embarked on a such project, we should expect they've got an outpost in the Solar System.
Now, if that outpost would contact us, or be easily contactable, is a whole 'nother question.
|
|
| |
|
|
|
Dauphin
|
 |
Caught in a tuna net
Jan 1970
time: 05:37
|
|
quote:
Originally posted by Last Conformist
I don't see why travel times is such an issue.
Imagine that some alien planet sends out a spaceship that needs a million years to reach the next star. Once there, it establishes an outpost, and builds a new ship. The mother planet does likewise (after watching reruns of Family Guy for a million years). In a further million years, these two ships arrive at two new systems. Repeat.
In less than eighteen million years, there'll be an outpost at every star in the galaxy (except for some recently formed stars, and a few that will have gone supernova and blasted it's associated outpost to bits, but that's marginal).
|
I don't disagree with the potential of the principle but you do have a flaw in your method of calculating reproduction of colonies. Quickest way to demonstrate there is a flaw is to take the assumption that it takes 1 million years to reach the next star system, say that the distance is 5 light years, and the radius of the galaxy is 35,000 light years. It would therefore take 7,000 million years to travel the radius of the galaxy, which is considerably longer than your estimate of complete galactic colonization.
You have to remember that only colonies on the periphery of colonized space will be able to replicate and find new planets to colonize, and that will only be a small proportion of the whole.
|
|
| |
|
|
|
Boris Godunov
|
 |
Portland, OR
Aug 2001
time: 00:37
|
|
quote:
Originally posted by Darkstar
BS. There *are* no experts in interstellar travel here. |
Um, but we have experts in in physics. They're called physicists. Might want to read something from them sometime.
quote:
What we know is that, for us, the economics are against it. But so was a direct China-Spain exchange of goods at one point on our *little* planet. |
The economics are certainly considerable, but that's nothing compared to the physical possibility. Again, talk to the physicists. If, as DanS mentioned, the theoretical max speed of an unmanned object is 1/10 c., then at that speed, things will take a long time to get anywhere and longer still to relay information back.
|
|
| |
|
|
|
reds4ever
|
 |
of the Spion Kop
Mar 2001
time: 05:37
|
|
quote:
Originally posted by Dauphin
And, there is nothing wrong with the Drake Equation except that its margin of error is so huge its of no practiucal use. Pin down the variables and you are getting somewhere useful. |
The fact that is of no pratical use means theres nothing wrong with it?
The equation may or may not hold water when the right numbers are plugged in, the thing that annoys ne is that people use it as mathematical proof that intelligent life must exist.
When your first variable is such a large number (ie stars in the galaxy), all the other numbers can be pretty much anything you like (>1) and you'll get an answer that tells you the gaxaxy is teeming with life!
Last edited by reds4ever on 04-07-2004 at 19:50
|
|
| |
|
|
|
Boris Godunov
|
|
Portland, OR
Aug 2001
time: 00:37
|
|
quote:
Originally posted by Dauphin
Thats not an issue of distance to other planets, thats an issue of our technical ability to detect something like a probe in our solar system, and looking at the right place and the right time. |
It is an issue of distance. If the sentient species was in the next star system over, then yes, we'd be teeming with their probes, probably. If they were even 20 ly away, we'd probably be teeming with them. But if it's 10,000 ly (which is far more likely, given that very special conditions seem to be needed for life, not to mention intelligent life), then the likelihood for them to have sent a bunch of probes our way in a time frame where they probes could detect our sentience (which is a very small window, relatively speaking) is remote, not to mention their ability, once the info got back to them, to actually do anything about it.
|
|
| |
|
|
|
Boris Godunov
|
|
Portland, OR
Aug 2001
time: 00:37
|
|
Distance is STILL an issue, because at greater and greater distances, the usefulness of them knowing about us is diminished. If they're 10,000 ly away, then it would take 100,000 years, at the LEAST, to get a probe here, and then how many more years for it to get back to them, and then how many more years for them to do something about it? Add up all those years and you get a huge time span for them to get info about just one system 10,000 ly away. But if they were 4 ly away, then those problems would be much less. We would, probably, have meaningful contact with them by now (assuming they were very advanced). So distance is indeed a factor, because the further away you are, the feasability of meaningful contact diminishes.
Timing and detection on our part are big problems, too, yes. I've been saying that. But you can't just dismiss vast interstellar distances as having no consequence to contact.
|
|
| |
|
|
|
Dauphin
|
|
Caught in a tuna net
Jan 1970
time: 05:37
|
|
quote:
Originally posted by Boris Godunov
Distance is STILL an issue, because at greater and greater distances, the usefulness of them knowing about us is diminished. If they're 10,000 ly away, then it would take 100,000 years, at the LEAST, to get a probe here, and then how many more years for it to get back to them, and then how many more years for them to do something about it? Add up all those years and you get a huge time span for them to get info about just one system 10,000 ly away. But if they were 4 ly away, then those problems would be much less. We would, probably, have meaningful contact with them by now (assuming they were very advanced). So distance is indeed a factor, because the further away you are, the feasability of meaningful contact diminishes.
Timing and detection on our part are big problems, too, yes. I've been saying that. But you can't just dismiss vast interstellar distances as having no consequence to contact. |
We are not discussing meaningful contact, we are discussing detection.
Edit - I'm not dismissing the vast distances as being important for any meaningful contact. Put it this way. Assume that every star was only a years travel distance from any other. That change would in only a minor way effect the probability that we would have detected a probe coming from another star. This is because the number of potential stars that probes could have been sent to is so large that we may not have been sent one, even if we were sent one it could have been at any time in history, and even it occured in the last 100 years it would still be highly unlikely that we would have been able to see it.
Last edited by Dauphin on 04-07-2004 at 20:31
|
|
| |
|
| |
All times are GMT. The time now is 05:37.
Apolyton Time is 00:37. |
top of page
|
| archivepost |
|
Forum Rules:
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
|
HTML code is ON
vB code is ON
Smilies are ON
[IMG] code is ON
|
|
|
|
|
|
04-07-2004 16:16
|