Is Interstellar Travel Impossible?

[Lemur]

I found this an incredibly depressing read. Charles Stross sketches out the practicalities of interstellar travel, and outlines why it's impossible without breaking known laws of physics.

The long and the short of what I'm trying to get across is quite simply that, in the absence of technology indistinguishable from magic — magic tech that, furthermore, does things that from today's perspective appear to play fast and loose with the laws of physics — interstellar travel for human beings is near-as-dammit a non-starter. And while I won't rule out the possibility of such seemingly-magical technology appearing at some time in the future, the conclusion I draw as a science fiction writer is that if interstellar colonization ever happens, it will not follow the pattern of historical colonization drives that are followed by mass emigration and trade between the colonies and the old home soil.

If you've got some time to kill, I strongly suggest you give the full essay a read. It's well-written, and translates a lot of potentially jargon-filled concepts into good, plain English.

So what do the Orgahs think? If we discovered a rocky planet in the Goldilocks zone a few light-years away, could we even get to it? Will we be able to eye it as real estate?

Is Stross's contention valid, or is he like Sir William Thomson, who proved mathematically that a steamboat could never cross the Atlantic?

[GeneralHankerchief]

Obviously, I haven't read the entire article yet, but from your post I get the gist of what he's saying.

Unfortunately, he's right.

So far (unless you count hypothetical tachyon particles), it's been pretty much proven that light is the galactic speed limit. The nearest star is something like 4.3 light years away, so even if we somehow manage to load up a massive rocket with enough people to make colonization worthwhile and enough provisions to make the trip and life self-sustaining (damn near impossible in itself) travel at the speed of light, those people will be on their own.

Now, that's just the closest star. Imagine if there are no habitable planets orbiting it. That means we have to go even further out, but we can't go too much further. Remember, the people colonizing further planets have to be able to live there, so the trip can't take too long. Problem is, the Milky Way has a radius of approximately 50,000 light years. We are in a fairly uncrowded sector of the galaxy, meaning there are less stars to pick and choose from. And some of those stars won't work at all, regardless of whether or not there are planets. The giant stars and above, the ones that go "boom" when they die, emit so much deadly radiation that planets would be uninhabitable. Also, despite their sizes, their life cycles are only one to two million years, so we'd just have to pack up and move again.

If we're going to colonize, it's going to be in our solar system, namely Mars. The Mars Society does a pretty good job of explaining how we can terraform the planet. It's not just science-fiction. Here's their promotional video on Youtube.

[Shahed]

The problem is that the author is living in the present and projecting current norms onto the future.

UTTER NONSENSE.

[Marshal Murat]

I don't know. I'm waiting for wormholes.

[Mikeus Caesar]

General - the problem with Mars is that it's atmosphere is only 2% of the density of Earth, so even if we could terraform it, nothing above a simple moss would be able to live there.

Venus on the other hand, while being more of a challenge, does have a higher chance. It's got a good (if rather overheated atmosphere) and is the same size as Earth! And how is it more of a challenge? Because it has no hydrogen!

Face it - unless we wear suits while outside and live in pressurised bubble cities, the colonisation of other planets is impossible. Unless we do somehow come up with interstellar travel and find another planet similar to Earth, we're doomed. Doomed i tells ya.

[GeneralHankerchief]

General - the problem with Mars is that it's atmosphere is only 2% of the density of Earth, so even if we could terraform it, nothing above a simple moss would be able to live there.

I forget the exact specifics, but Robert Zubrin, the founder of the Mars Society, proposed some machine that could send gas over or even make it on-site. A quick skim of the Wiki page says something about shuttling gas over from Earth.

Not exactly efficient, but it'll get the job done.

[Shahed]

Right now, we cannot achieve this. Now talk about 10,000 years from now. How about 30,000 years. The universe is infinite, therefore time is infinite. If we survive long enough, we will have the means to travel light years, taking our preferred habitat (McDonald's & Britney Spears) with us !

What are the laws of physics ? Have they changed in the past 1000 years ? Yes our understanding of the laws has changed dramatically, even though the laws have not, BUT we never understood the laws in the first place. And we still don't. Today's Einstein is tomorrow's Charlie Chaplin. Keep in mind our whole entire current scientific conciousness barely spans 200 years. What is this conciousness compared to the conciousness of the universe; nothing at all. Barely even a grain of sand.

Whether we can develop our technologies fast enough to escape the inevitable destruction of the Earth, is another question.

Meet you at the gate to New Eden !

[TevashSzat]

Through normal sublight travel? Impossible. Its near impossible to even travel at light speed because as your speed approaches light speed, the amount of energy needed to go faster increases infinitely.

There a few theoretical ways to do so, one of which is wormholes, but the problem is that it takes an inmense amount of energy to create one and the ones that are created are like on the subatomic scale and collapse in life a second(possibly due to dark matter?0

[Ramses II CP]

Almost everyone misses the obvious here, how much longer do you expect humanity to be tied to biology? Prepare yourselves for the post-body world. It's rushing down the pipe so fast it'll hit like a meteor. Tell your children, it's information they'll need.

All these problems of how to get human beings to other worlds are a joke. If we want bodies at Beta Lyrae we'll send the information necessary to build them, speed of transfer being irrelevant due to the absurdity of the idea of interstellar simultaneity. Which is to say, there's no point in trying to coordinate actions between 'here' and 'there' over such distances, there's just preparing a package which can self sustain when it arrives and letting it go.

Human bodies will never make it even so far as Mars, and so much the better. Evolution was an excellent designer for the medium within which it operates, but we're just about done with that place and it's time for intelligence, which grinds less fine but far, far faster, to take over the role.

'We' will make it as far as it's purposeful to go, it's just a matter of what 'we' look like when we get there.

[GeneralHankerchief]

On a related note, NASA is beaming the Beatles into space.

If you can ignore the usual amount of Beatles song titles inserted into the article (mandated by international law, apparently ) the fun part is how it'll take 431 years to get to Polaris - which is fairly close.

[Kagemusha]

I think Ramses II CP is right,its more probable that our own limitations will change in the future. If human conciousness can be altered in a form that it doesnt need a body anymore, we can send ourselves to far away distances without having problems with time. Damned the computers of our spacecrafts could start creating new bodies for us once we are near our destination, or it might that once human conciousness can be altered to electrical or another form, we will stop having bodies all together.

[English assassin]

Very interesting article Lemur, thanks.

[Viking]

Better still, if hydrogen sulphide-induced hibernation turns out to be a practical technique in human beings, we may be able to sleep through the trip. But even so, when you get down to it, there's not really any economically viable activity on the horizon for people to engage in that would require them to settle on a planet or asteroid and live there for the rest of their lives. In general, when we need to extract resources from a hostile environment we tend to build infrastructure to exploit them (such as oil platforms) but we don't exactly scurry to move our families there. Rather, crews go out to work a long shift, then return home to take their leave. After all, there's no there there — just a howling wilderness of north Atlantic gales and frigid water that will kill you within five minutes of exposure.

One thing though, is that it is a bit risky to put all your eggs in one basket. If some giant "comet" is heading for us, we'll have big problems trying to deflect it. I am not sure what sizes we are talking about, but according to wikipedia it is estimated to be at least 70,000 objects with diameters greater than 100 km in the Kuiper belt; objects at such sizes becomes tricky to deflect.

We are in a fairly uncrowded sector of the galaxy, meaning there are less stars to pick and choose from.

Remember that we cannot live on stars. The more stars in near vicinity, the less planets can accrete due to stars passing nearby.

Through normal sublight travel? Impossible. Its near impossible to even travel at light speed because as your speed approaches light speed, the amount of energy needed to go faster increases infinitely.

Have you seen any calculations on how much energy we'd need in order to travel at 1/2 the speed of light, or just 1/3. though?

Right now, we cannot achieve this. Now talk about 10,000 years from now. How about 30,000 years. The universe is infinite, therefore time is infinite.

Slightly off topic, but some astronomers propose that the universe will suffer from the heat death.

[macsen rufus]

it might that once human conciousness can be altered to electrical or another form, we will stop having bodies all together.

Sorry, can't buy this dualistic nonsense - human consciousness is an emergent behaviour derived from the complexity of the human brain - the body is an essential precondition. I don't deny the possibility we may be able to create some sort of artifical consciousness eventually, but it will be computer consciousness, not human.

I am persoanlly torn about the whole idea of getting off this planet - if we don't we're doomed indeed, maybe in a couple of decades due to our own cock-ups, maybe in a couple of billion years when our local friendly Sol goes nova. As fas as interstellar travel, I expect it will be one way - "seed ships" or "generation ships" whose descendents may find somewhere to get off. Then we'll never hear from them again and never know how they got on, until they swoop back down on us having evolved into interstellar octosquids

[seireikhaan]

Hmm, now correct me if I'm wrong, but this is what they teach us in physics nowadays. Basically, when a person/thing/object travels at speeds up to/near the speed of light, they will actually age slower than a person who's stuck here on earth, and thus, traveling to a planet that is, say, 75 light years away, is actually not impossible, so long as we overcome other boundaries such as supply of food and water, actually getting a vessel which can survive and continue at such speeds for the needed time, creating artificial gravity(so the astrounauts don't suffer space depression of their blood vessels, muscles, etc... and, of course, finding a way to get the human body to withstand the g-forces that such speeds would inflict upon us.

[Kagemusha]

Sorry, can't buy this dualistic nonsense - human consciousness is an emergent behaviour derived from the complexity of the human brain - the body is an essential precondition. I don't deny the possibility we may be able to create some sort of artifical consciousness eventually, but it will be computer consciousness, not human.

I am persoanlly torn about the whole idea of getting off this planet - if we don't we're doomed indeed, maybe in a couple of decades due to our own cock-ups, maybe in a couple of billion years when our local friendly Sol goes nova. As fas as interstellar travel, I expect it will be one way - "seed ships" or "generation ships" whose descendents may find somewhere to get off. Then we'll never hear from them again and never know how they got on, until they swoop back down on us having evolved into interstellar octosquids

It is not impossible after we can create neurological models as complex as human brains, after that all we need to do is to be able to transform intel from brains to artificial network and model the new concious being after ourselves. When these conciousness start to act and think like humans we are in our destination. Ofcourse you are right that these beings wouldnt be human anymore like homo sapiens, but something new, but thats evolution.

[Uesugi Kenshin]

Hmm, now correct me if I'm wrong, but this is what they teach us in physics nowadays. Basically, when a person/thing/object travels at speeds up to/near the speed of light, they will actually age slower than a person who's stuck here on earth, and thus, traveling to a planet that is, say, 75 light years away, is actually not impossible, so long as we overcome other boundaries such as supply of food and water, actually getting a vessel which can survive and continue at such speeds for the needed time, creating artificial gravity(so the astrounauts don't suffer space depression of their blood vessels, muscles, etc... and, of course, finding a way to get the human body to withstand the g-forces that such speeds would inflict upon us.

I don't think creating artificial gravity or sustaining massive g's would be a big problem. I think the main problem with interstellar travel is accelerating a ship large enough to offer a decent chance at having enough genetic variety, food, water, fuel and so on to survive the trip.

If the ship were to accelerate at one g or so for the whole incredibly long trip and the rooms inside were to be oriented with the floor end towards the engines you would have artificial gravity so long as the acceleration remained fairly constant. The only problem is this would take a really long time. But if you have a self-sustaining ecosystem on the ship then your only problem will be providing enough fuel to keep the engines going that long, not providing food, water, oxygen and anything else that may be needed.

[Kralizec]

Hmm, now correct me if I'm wrong, but this is what they teach us in physics nowadays. Basically, when a person/thing/object travels at speeds up to/near the speed of light, they will actually age slower than a person who's stuck here on earth, and thus, traveling to a planet that is, say, 75 light years away, is actually not impossible, so long as we overcome other boundaries such as supply of food and water, actually getting a vessel which can survive and continue at such speeds for the needed time, creating artificial gravity(so the astrounauts don't suffer space depression of their blood vessels, muscles, etc... and, of course, finding a way to get the human body to withstand the g-forces that such speeds would inflict upon us.

I don't think that it's the traveling (at a certain speed) itself that causes slower aging, but the acceleration. I could be wrong though.

I don't mean to sound harsh but I thought it was common knowledge that traveling at light speed or quicker is impossible. Now this wouldn't be the first time that science got things entirely wrong, but I'm not optimistic about it. It never stopped me from enjoying science fiction, though.

[seireikhaan]

I don't think that it's the traveling (at a certain speed) itself that causes slower aging, but the acceleration. I could be wrong though.

I don't mean to sound harsh but I thought it was common knowledge that traveling at light speed or quicker is impossible. Now this wouldn't be the first time that science got things entirely wrong, but I'm not optimistic about it. It never stopped me from enjoying science fiction, though.

Yes, you're quite right. Did I say it was possible? I thought I didn't, but I may have mistyped. It isn't impossible, though, as far as I know, to go 99.999999999999999999999999% the speed of light, at least theoretically. Correct if I'm wrong, though.

[Viking]

Hmm, now correct me if I'm wrong, but this is what they teach us in physics nowadays. Basically, when a person/thing/object travels at speeds up to/near the speed of light, they will actually age slower than a person who's stuck here on earth, and thus, traveling to a planet that is, say, 75 light years away, is actually not impossible, so long as we overcome other boundaries such as supply of food and water, actually getting a vessel which can survive and continue at such speeds for the needed time, creating artificial gravity(so the astrounauts don't suffer space depression of their blood vessels, muscles, etc... and, of course, finding a way to get the human body to withstand the g-forces that such speeds would inflict upon us.

Remember that gravity is acceleration. Travelling at 99% of the speed of light inflicts 0 G upon you since the ship does not accelerate.
The average surface gravity on Earth is 9.81 m/s² , so if the space ship had a constant acceleration of 9.81 m/s² the crew would at all times experience ~1 G. With this constant accelertaion however, you'd theoretically reach the speed of light within 354 days or so, so before you reached c, you'd need a constant deacceleration of 9.81 m/s² also in order to keep the gravity it constant. All this would of course require insane amounts of energy.

Spoiler Alert, click show to read: 

There was an interesting thread over at the Uplink Space forums regarding travel at the speed of light:

http://uplink.space.com/showthreaded...&sb=5&o=0&vc=1

(click Flat at upper left in order to see whole thread).

I don't think that it's the traveling (at a certain speed) itself that causes slower aging, but the acceleration. I could be wrong though.

I think both high speeds and high acceleration causes watches to go slower.

Edit: At least high speed does http://en.wikipedia.org/wiki/Time_Di...d_space_flight

[Uesugi Kenshin]

Remember that gravity is acceleration. Travelling at 99% of the speed of light inflicts 0 G upon you since the ship does not accelerate.
The average surface gravity on Earth is 9.81 m/s² , so if the space ship had a constant acceleration of 9.81 m/s² the crew would at all times experience ~1 G. With this constant accelertaion however, you'd theoretically reach the speed of light within 354 days or so, so before you reached c, you'd need a constant deacceleration of 9.81 m/s² also in order to keep the gravity it constant. All this would of course require insane amounts of energy.

That's more or less what I was trying to say, but you said it much better!

[Kralizec]

I think both high speeds and high acceleration causes watches to go slower.

Edit: At least high speed does http://en.wikipedia.org/wiki/Time_Di...d_space_flight

From the little that I know of these things, I remember that all movement is relative. Our solar system is moving away from the point where the big bang would have taken place, but we don't feel it. If a spaceship is accelerating, away from our system and towards this "point of origin", viewed from that point of view the spaceship is still moving away but at a decreasing speed ( eventually standing still and then moving towards it). But from our point of view, we're motionless and the ship is moving away at increasing speed.

From a PDF file linked to on that wiki page:

In conclusion, in the case of a purely accelerated motion of the clock which moves to-and-fro along a spatial straight line, a differential aging with respect to the rest clock takes place.

So traveling away from and back to Earth does make you age less compared to the people on Earth, but it's because you have to accelerate (and decelerate when you want to go back) to do it.

[Abokasee]

I think Ramses II CP is right,its more probable that our own limitations will change in the future. If human conciousness can be altered in a form that it doesnt need a body anymore, we can send ourselves to far away distances without having problems with time. Damned the computers of our spacecrafts could start creating new bodies for us once we are near our destination, or it might that once human conciousness can be altered to electrical or another form, we will stop having bodies all together.

But isnt that how Total Annhilation started, the core finally over came death by transfering the brain into a digital (or something simular) media which could intern be built into a robot and that would be the new body, but some people didnt like this so, they moved to the edges of space and cloned there finest warriors and put them into large armoured mechs, core responded by digitalizing there best soldiers onto robots that would then be mass-produced and then the war erupted and it went on and on for millienia.

But I would love to be built into a robot, in a childish way that my mind seems to be good at, but what about the human erges of sex, booze and other such things,

wow I never knew interstellar travel could be this dam complicated

[Crazed Rabbit]

Not much of a surprise in the article.

I agree with Sinan is that he looks at this too much from the technology we have now. We went to the moon in 1969. To a person merely a hundred years before, that would have seemed magic. I believe twas Asimov who said that all sufficiently advanced technology will look like magic.

So we don't really have the capability now, but it appears as if the article assumes we, as in humanity, never will. What of the technologies 1000 years from now? You can't limit the future exploration possibilities by the technology of today. Of course, none of us or our near descendants will see it come to pass.

(Funny, though, how he spoke ill, rightly, of waving a magic wand, and so many people popped up talking about transferring consciousness and the like.)

CR

[Mouzafphaerre]

.
Never ask such things to a Trekkie & BS Galactica fanboy you silly primate!
.

[TevashSzat]

I don't think that it's the traveling (at a certain speed) itself that causes slower aging, but the acceleration. I could be wrong though.

Well actually it is the speed actually not the acceleration. The sole reason that all light we see are as old as the day they formed because they travel at the speed of light which, btw, does not allow for further acceleration.

Right now, a person can either travel through space or time. You can travel through both, but if you travel through space, you travel slightly slower through time. Now since humans travel at very low speeds relative the the speed of light, we don't notice the distortion in time, but if your travel at even 50% of the speed of light, you will notice a major difference in your progression through time compared with those traveling at a significantly lower speed

[Gregoshi]

I believe twas Asimov who said that all sufficiently advanced technology will look like magic.

Correction...

(Arthur C.) Clarke's Third Law:

Any sufficiently advanced technology is indistinguishable from magic.

His First Law applies to the article:

When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong.

Clarke's Second Law applies to the subject at hand:

The only way of discovering the limits of the possible is to venture a little way past them into the impossible.

[LeftEyeNine]

- What happens when time stops ? Or is it a concept that can shift its "shape" (perception) according to the surrounding of the subject(s) ?

- Is time a prequisite for our existence and conscious ? (We "live" and "die")

- Is there something called "time" beyond the speed of light ?

- Does an arrow fly towards a target, bound to a duration ?

- Or is it a matter of change in the arrow's place in space, the arrow always stops, is not bound to a duration (time), but the "duration of the flight" is created by energy ?

- If so, are energy and time "symbiotic" concepts ? (The flight of the arrow, hence the duration was an effect of the energy)

- So depending on Einstein's claim that time would (feel) stop(ed) as a substance reaches the speed of light, could we keep our mass there and beyond ? Or as, he claims again, do we (mass) need to transform into pure energy to compete with time's boundary ? If so, what about the human conscious which we truly need for the outcome of such travel, humanly survival ?

Rather than "humongous needs of energy" issue, I think the existence is a bigger question mark for a post-light speed travel. 'Cause its solution will reveal a stunningly easier way about the "energy needed to travel". If there ever is, of course.

But I believe there is.

P.S. Has been a fun brainstorm sequence for me, Lemur. Thanks for the ride.

P.S.S. Post-human ideas such as artificial consciousness or a "über body" or something else to carry the "wisdom" seems nonsense to me. You'll still be needing energy for its survival to the destination. That would be like tying another knot to your problem. Human body is already a form of energy, we just don't know about what really existence is.

[Alexander the Pretty Good]

Stross gets into the downloading conscienceness stuff in his book Accelerando which is pretty good (until the end where it got even weirder exponentially).

[Raz]

Pfft - in my mind the magic wand will always be there.

Also, why is more than 90% of the page filled with comments?