The nearest star to ours is still several light years away. With conventional means the distance is too far to reach, unless the life span of humans grows exponentially. To get there in any reasonable amount of time(albeit still years) it would take near or at light speed travel. By the closer to the speed of light you come, (supposedly)the slower time outside passes. If it's true then by the time you went there and back the Earth as you know it would be completely different, even though the journey only took you 10 years. Because of this wouldn't interstellar travel be pointless, regardless of how fast you could travel? The only way for it to be feasible would be if humans could live for thousands of years needed to properly travel between stars.
-
Welcome to Smogon! Take a moment to read the Introduction to Smogon for a run-down on everything Smogon, and make sure you take some time to read the global rules.
does interstellar travel matter?
- Thread starter Quaily
- Start date
No.
We'll assume no FTL travel, because the physics of that is possibly impossible at worst, and not understood at best.
Interstellar travel will be only possible if you use huge colony ships, like they use in various science fiction tales. You'd need agricultural sector to grow food and oxygen production, education to train people, etc. The people who would actually colonise would be the Nth generation shipborn children.
You'd also be totally independent of Earth and other colonies if you didn't have FTL communication.
You've got your relativity wrong. If you take a trip at near light speed to Alpha Centauri and back, viewed from Earth it will take about ten years, while experienced by YOU it could take only a few months, or even weeks.
Thus, it's entirely possible to go exploring the Universe. But people on Earth will have to wait a long time for you to bring your results back. (EDIT: Fixed)
One way around that problem would be to have a very large spacecraft, with a substantial portion of the human race. A massive engineering challenge, but within the realms of known physics and technology.
If that were to happen, one natural consequence would be speciation. Were the nomads to return to Earth, they could well find they were no longer able to interbreed with the Earthbound humans.
Another issue with interstellar travel is you will likely be overtaken.
Thus, it's entirely possible to go exploring the Universe. But people on Earth will have to wait a long time for you to bring your results back. (EDIT: Fixed)
One way around that problem would be to have a very large spacecraft, with a substantial portion of the human race. A massive engineering challenge, but within the realms of known physics and technology.
If that were to happen, one natural consequence would be speciation. Were the nomads to return to Earth, they could well find they were no longer able to interbreed with the Earthbound humans.
Another issue with interstellar travel is you will likely be overtaken.
Fixed.
Speciation would take a long time, I think. Like, 10s of generations at least.
What do you mean by overtaken?
I am of the belief that there is much much more to physics than we will ever know. I have my own half baked theories about how humans can colonize the universe. However the most interesting technology is that of "teleportation". Scientists have been able to transfer the information from one atom to another atom in a nearby area. If you could channel this energy then you could hypothetically "beam" your physical manifestation somewhere else.
Another idea that is linked to this is the idea that humans could manufacture drives that could turn ships into "zero point energy" or the material that matter is made out of. This matter could be unrestrained by physical laws and thus could do all sorts of physically "impossible things". We maight even see this technology come to use in our lifetimes which would be very cool. It may sound insane but the rule of thumb in science is to never say never.
Another idea that is linked to this is the idea that humans could manufacture drives that could turn ships into "zero point energy" or the material that matter is made out of. This matter could be unrestrained by physical laws and thus could do all sorts of physically "impossible things". We maight even see this technology come to use in our lifetimes which would be very cool. It may sound insane but the rule of thumb in science is to never say never.
We don't have a way of converting matter into light while maintaining all it's information; teleportation of information is a different phenomenon to teleportation of matter. So yeah, we can't do that...
Yet.
Teleportation does seem like the best way to move of course, but that's a big can of worms we don't even begin to understand. At least we can get to mars. I guess what I'm getting at here is that we are never going to see beyond earth, and we are never going to find out if it's truly unique. It's kind of depressing but it gives you perspective on what you should do with your life.
Interstellar Travel can and most probably will matter. Lets face the facts, one way or another, Earth will eventually be unhabitable. Whether it be from the Supernova of Sol, the collision of the Milky Way and Andromeda Galaxies, or the Super-massive black hole in the center of the Milky Way expanding (all probable, by the way), humanity will need a new home. Thus, interstellar travel, and colonies or independent planets will be needed in order to sustain the human race. Keep in mind, these cataclysmic events will be in several millenia, so we have plenty of time.
Gah. Relativity is a pain.
Speciation would indeed take a long time. But I'm envisioning journeys of tens of thousands of light years. Cyngus X-1 might be a great destination; the nearest black hole at 6000 light years away. (Obviously be careful not to HIT it!)
By overtaken, I mean that the first craft to set off would be fairly primitive, and have a relatively low acceleration. Later on on Earth, faster and better craft could be built. These would reach further distances from Earth than the first craft, ie the first craft are 'overtaken' (even though they'd likely be heading in a different direction).
Communication between Earth and the craft might be possible. You have to contend with pretty severe redshifts though. The larger the craft, the better, since a larger craft can carry a larger antenna, which thus resonates at lower wavelengths. I haven't done the calculations to figure out how much power would be needed.
Of course, there is a REALLY outlandish option. Move the whole Earth. I think the energy requirements would be prohibitively high though.
Red shift wouldn't be that much of a problem, especially if you used some heterodyning techniques and the like; the lightspeed communication limit would be a greater barrier because of the diminishing intensity and the 4 year time delay between sent/received from even the closest star.
One, the sun will never end in a supernova. It's not large enough. It'll become a red giant, and engulf Earth eventually.
And two, all of the events you listed and I listed will take billions of years. Yes, billions. Not several millenia. In several millenia, Earth will be very depleted in exploitable resources, so travel within the solar system and to other systems will be needed to obtain resources.
I think the redshift is alright actually. At 99% of the speed of light, the received frequency is 1/14 of the transmitted one. We can effectively use radio frequencies over a good 5 orders of magnitude or so (from around 100 kHz to 10 GHz), so there's plenty of room to manoeuvre. The accelerating spacecraft will result in a changing redshift, which is a pain because radio antennae are tuned, but the issue is surmountable (log-periodic antennas are broadband, and physically changing element sizes is possible)
The internsity issue I think can be got around. It's possible to make very high powered transmission (500 Megawatts is known), and it's possible to receive very faint signals.
The lightspeed delay is of course insurmountable. But old news is better than no news.
The practicable time for communication would mean that all you'd have were Wikipedia-like data entries for cataloguing. Everything else would take too long, so you'd otherwise be ostensibly independent from the mother colony.
Also, I expect you'd probably use integrated circuit or photonic receivers, rather than the standard dipole antennae.
Suppose we could somehow develop technology which allows humans to put themselves in some form of "stasis". It could be similar to what a virus is capable of, going into a dormant state to prevent aging. In essence the people would be dead until revived. This seems more likely than prolonging human life to a thousand years.
Of course in order for interstellar travel we would need some form of transportation that is fucking fast. A method of traveling almost as fast as the speed of light would be necessary. If we could travel faster than light it would make things alot easier but it's supposedly impossible.
supposedly it would take a piece of dark matter the size of jupiter to go faster than the speed of light, and the energy of an entire sun to travel back in time.
Dr. Michio Kaku talks about it a shit ton on the science channel if anyone is interested in learning more about it.
He also talks about time travel and traveling to parallel universes; speculation for the most part but it makes you really wonder how awesome the future might be in the not so distant future.
Not trying to declare anything as truth here im just the messenger, and im sure its not all figured out yet.
Dr. Michio Kaku talks about it a shit ton on the science channel if anyone is interested in learning more about it.
He also talks about time travel and traveling to parallel universes; speculation for the most part but it makes you really wonder how awesome the future might be in the not so distant future.
Not trying to declare anything as truth here im just the messenger, and im sure its not all figured out yet.
LMAO what. No, this is bullshit, I'm afraid.
Oh man...here I go.
For interstellar travel to matter several criteria need to be met.
1. Some form of stasis must exist to allow the same people to start and end the trip in relatively the same physical condition.
This is the most important concern. If a traveler is unable to survive the journey, then what's the point in going in the first place? Generation ships aren't a very good idea either. What happens if one generation decides that the rest were full of shit and they want to go home? Also, having the same crew from start to finish means a lot less work and effort involved in training new generations, less information is lost, and less weight is used in supplies to keep several generations of human beings alive. Of course, we are assuming a human crew is needed, because if it is not, this entire discussion is rendered pointless.
2. The traveler must have a destination worth traveling to.
That's pretty obvious. Nobody is going to want to go out and miss tens or hundreds of years of history for the sake of an interstellar journey unless there is a very good reason for it. Scientific explorations might find that during the time it took for them to make their journey, it was made pointless by some advancement back on Earth that made humans able to collect the same data from Earth. The only solid reasons that i can think of are colonization, immigration, and inter-colony trade. The third of these things I believe deserves special mention. If somebody is going to be trading between worlds, they will be spending a LOT of time in travel, missing a lot of history as a result. They would have no reason to have attachments in the outside world, because they would obviously never see the same person twice, etc. Imagine crews of traders traveling from star to star over hundreds of years, returning to the same system only after several centuries. Quite the thought, no?
3. Somebody need to be willing to BUILD these ships.
Consider this point. To build one of these ships would be unimagineably expensive. To be able to withstand the rigors of interstellar travel would require enormous ships sheathed in incredibly thick shields (maybe made of ice, it's cheap) to protect them from impacts. To push this bulk through constant acceleration for hundreds of years would take incredible amounts of fuel, which also adds to the weight. The time, effort, and finances required to build something like this would be spectacular, on the scale of national funding for years. Who has that money and is willing to use it on an investment that might not pay itself back for several hundred years?
For interstellar travel to matter several criteria need to be met.
1. Some form of stasis must exist to allow the same people to start and end the trip in relatively the same physical condition.
This is the most important concern. If a traveler is unable to survive the journey, then what's the point in going in the first place? Generation ships aren't a very good idea either. What happens if one generation decides that the rest were full of shit and they want to go home? Also, having the same crew from start to finish means a lot less work and effort involved in training new generations, less information is lost, and less weight is used in supplies to keep several generations of human beings alive. Of course, we are assuming a human crew is needed, because if it is not, this entire discussion is rendered pointless.
2. The traveler must have a destination worth traveling to.
That's pretty obvious. Nobody is going to want to go out and miss tens or hundreds of years of history for the sake of an interstellar journey unless there is a very good reason for it. Scientific explorations might find that during the time it took for them to make their journey, it was made pointless by some advancement back on Earth that made humans able to collect the same data from Earth. The only solid reasons that i can think of are colonization, immigration, and inter-colony trade. The third of these things I believe deserves special mention. If somebody is going to be trading between worlds, they will be spending a LOT of time in travel, missing a lot of history as a result. They would have no reason to have attachments in the outside world, because they would obviously never see the same person twice, etc. Imagine crews of traders traveling from star to star over hundreds of years, returning to the same system only after several centuries. Quite the thought, no?
3. Somebody need to be willing to BUILD these ships.
Consider this point. To build one of these ships would be unimagineably expensive. To be able to withstand the rigors of interstellar travel would require enormous ships sheathed in incredibly thick shields (maybe made of ice, it's cheap) to protect them from impacts. To push this bulk through constant acceleration for hundreds of years would take incredible amounts of fuel, which also adds to the weight. The time, effort, and finances required to build something like this would be spectacular, on the scale of national funding for years. Who has that money and is willing to use it on an investment that might not pay itself back for several hundred years?
You'd never get a generation who entirely wanted to leave, and besides, it's not within their power to do so. It's like saying "What if a generation of people in New York state decided they want to live on the moon?"
A colony ship is therefore still reasonable, indeed moreso than medical stasis, which is yet to exist.
Interplanetary commerce would require FTL travel, I think. Otherwise there wouldn't be enough profit for the investment.
You actually wouldn't need that much fuel for the continued journey; you'd burn most of it off escaping Earth's gravitation. Once you're in space, you'd just need peripheral jets to adjust direction, otherwise you'd just let momentum carry you, the way contemporary rockets and satellites do.
I agree on the rest, though.
But that's irrelevant, seeing that interstellar travel doesn't exist yet either. I don't think discussing the comparative merits of nonexistent technologies makes very much sense.
That assumes that you have a target velocity, and drag (though minimal in space) is not a factor.
If somebody actually wants to reach their destination in a reasonable amount of time, they would more than likely choose to sustain several g's of thrust throughout the entire voyage, or at least until they reached 80% or so of light speed (which would take several decades of sustained thrust). I guess it depends on what matters more, speed or cost. Also, although it is relatively negligible, over hundreds of years there would be a noticeable slowing in a ships speed, which would have to be compensated for by burning fuel.
Well, I wanna bring up an interesting point:
Well, we're going to assume that the primary motivator for interstellar travel is the inability of Earth to support some or all of the human population. Why do we assume that we can break the laws that govern the populations of animals? Just because we have science? I believe that there comes a point where we simply cannot save ourselves. We may want, or even need, to find a new inhabitable planet, but have you considered that even in our most dire need, human ingenuity shall eventually fail us, causing massive death or extinction as a species? We are but one incredibly small speck of dust on the timeline of the Earth, let alone the universe. I believe that our time will come to end, and that will simply be it.
/rambling
Well, we're going to assume that the primary motivator for interstellar travel is the inability of Earth to support some or all of the human population. Why do we assume that we can break the laws that govern the populations of animals? Just because we have science? I believe that there comes a point where we simply cannot save ourselves. We may want, or even need, to find a new inhabitable planet, but have you considered that even in our most dire need, human ingenuity shall eventually fail us, causing massive death or extinction as a species? We are but one incredibly small speck of dust on the timeline of the Earth, let alone the universe. I believe that our time will come to end, and that will simply be it.
/rambling
There's proof of principle for interstellar travel using huge colony ships; it's not practicable or affordable, but it's theoretically sound. Stasis-lock is still entirely within the realms of science fiction.
I'm also using a variant of Occam's Razor; create a solution using the minimal number of assumptions and inventions.
Well, the target velocity doesn't matter so much (you would be using gravity-aided acceleration effects to travel out of the solar system, as with satellites anyway), but it does assume you're not trying to get there in as short a time as possible. If you're actually racing, you have a bit more of a problem since you will only be able to accelerate up for the first half of your journey (You'd need to accelerate down again in order to stop when you reach your destination). Since carrying the extra mass of fuel out of Earth's gravity well actually prevents you from being light enough to escape without dumping the excess containers, the race methodology will probably always be unfeasible short of some superefficient engine that yet does not exist.
In regards to drag, if you were going beyond the nearest stars, you'd probably need the extra thrust, but for anything reasonably travellable without near-light or FTL travel, the drag wouldn't be a problem in the slightest, especially when you consider that drag is inversely proportional to the density of the moving object, and a spaceship has a great deal of mass, and the ISM has almost none.
Relativistic effects make this a given, if the craft can reach sufficient, less than light-speed, velocity.
I think here you forget that it is the nature of some people to explore. We've been doing it for generations.
The cost aspect is a major point. However, it's only a show stopper if you think of your first destination as being the stars. Consider instead a progression, with increasingly high-performing ships being used to travel out own solar system, in time becoming as mundane as aircraft are today. Then you might start to explore (and exploit) the outer reaches of the solar system. With that kind of progress from today, humanity is that much closer to interstellar voyages. And indeed, though I envisage us travelling the galaxy (if we don't destroy our civilization and go extinct), a journey of a million light-years must begin with a single step.
One g is probably a good thrust to use. That gives you an artificial gravity equal to that of Earth, which is nice to have. You could run less if it makes things cheaper or easier, but you wouldn't want to run much more or daily activity on board the ship would get difficult.
Oh I agree, this is the more probable outcome. But that doesn't mean we should not discuss space travel; quite the opposite.
This applies to an extent no matter what. Even if you coast for some of the journey, you need as much deceleration at the destination as you need acceleration at the start, unless you do gain a significant amount from ISM drag.
You don't build your interstellar spaceship in low earth orbit! You'd probably want to build the spacecraft far from the sun, and not orbiting any planets or satellites, unless you do plan on using boosters. I guess you have a trade-off - the closer you build to your raw materials, the less fuel you require shipping them from source to spaceshipyard, but then the more work the ship itself needs to do. You'd want to get your materials from somewhere without a deep gravity well. Outer moons of Jupiter or Saturn, perhaps, though they are rather small. Or the asteroid belt. Or perhaps even the Kuiper belt.
Or the likely event that Earth's Moon will be the most developed and industrialised solar system body after Earth itself may make that the only place where sufficient materials, technology, and expertise can be had to build the interstellar spacecraft, making the construction location lunar orbit or a Lagrange point.
I am still believe that the universe has many unlocked but very potent secrets that will one day allow us to reach from one end of the other. Constricting ourselves to the space time continuum or to light speed (which actually isn't all that fast) we will never reach the far ends of our galaxy. Science is the study of the unknown and I believe that there are unknowns which provide the gateway to the universe.
You could do this, although if you were coasting instead you could just use rotation of the place to create artificial gravity too.
Yes, but if you're only coasting, you don't have to slow down as much at the other end, which means your net fuel costs get MUCH smaller.
Actually, that's a good point, although even just constructing it in a high Earthly orbit would be enough to reduce the amount of thrust you need.