I understand that projects such as Project Orion and Project Daedalus propose a healthy %c travel. Would this allow you to take advantage of Einstein’s Time Dilation? In other words could you fly away (and back) fast enough to put you into the significant future upon return.
I know it’s theoretically possible, I’m wondering if we can do it with current technology.
The reason I’m asking: Having heard that downloading consciousness is being taken seriously by some, I’m wondering (assuming you were rich enough to afford building the rocket(?) in the first place) if it could get you far enough in the future to take advantage of this and if it would be worth the risk to try.
I know this a terribly convoluted first post. I apologize in advance.
Not travelling to the future is what’s most difficult; we’re all headed there.
Possible methods of travelling to the future at a rate apparently faster than 1 s/s:
-Have yourself frozen and revived at some time in the future.
Pros: requires less energy than near-lightspeed travel energy, and you get to stay at home while you travel
Cons: It might not work, even if it does become possible to revive you, they might just not bother.
-Travel at significant fraction of light speed.
Pros: Known to dilate time (so that bit is guaranteed to work)
Cons: (Very, very)Energy-hungry, quite risky if you hit a rock or something.
-Download your mind into a computer.
Pros: Immortality, Missster Anderson!
Cons: Not possible right now, perhaps never. What if the power fails and the backup media was corrupt?
General Con for all methods: If you get to the future and don’t fit in, or just don’t like it, you can’t come back.
I know time travel threads get bashed a lot. That’s why I wrote, “could you fly away (and back) fast enough to put you into the significant future upon return.” I’m thinking a little more than seconds.
My main question, though, was could we with current technology build one of these ships.
Time would appear to a stationary observer to run slower in a moving system by the factor of the stationary time lapse divided by the square root of one minus the ration of the square of the velocity of the moving object and the square of the speed of light.
For the value of thirty thousand kilometers per second, that works out to a one percent change in time rate. A hundred thousand kilometers per second would give you a bit more than a five percent difference.
Of course, the observation is entirely theoretical, since you can’t see it, and you can’t come back and measure it either, without opening up an entirely different can of worms.
Induced hypothermia, already in use in some surgeries and occasionally putting a patient down for up to 19 days, is a much more promising avenue than building a near-c spaceship. If we do get such ships, I hope their primary goal will be establishing extraterrestrial colonies, with time dilation being a relatively minor footnote, since we know it’ll happen, anyway.
For the current (or at least conceivable within twenty years or so) state of the art, Scientific American and Popular Science and other mags periodically run articles.
Philosophers have dicked over this endlessly but I’d like to point out that every atom in your body has been replaced at least once over the last 7 years or so. Does this mean that you are now a copy?
I’m not convinced there’s a great deal of difference; my unconscious mind booted into wakefulness this morning in a way that could just as easily be derscribed as being a copy of ‘me’ from yesterday; it just happens to be running on the same hardware.
Please note that the cultural shock of traveling a mere 40 years into the future would leave you severely depressed, withdrawn, alienated, subject to chronic panic attacks, & completely unemployable.
No. With existing technology–and we’re talking Sixties-era tech here–we could build an Orion-type vessel that could concievably attain a large fraction of of a percent of c. At .01c dialation effects work out to about 1 part in 20000, or a .005% decrease in experienced time (by someone aboard the vessel); this is measureable–about half an hour difference over the span of a year–but not significant. Faster velocities–those necessary for interstellar travel within a reasonable timeframe–will require higher impulse than an Orion-type vessel can provide; a Daedelus-type fusion proplusion system could probably achieve a few percent of c, but there are two limiting factors to any type of conventional propulsion system; the maximum impulse it can achieve (i.e. the momentum flux of the propellant) and the compound effect of needed reaction mass (i.e. the faster you want to go the more mass you have to carry, which forces you to carry yet more mass to propel the extra mass, which forces you to carry more mass, ad infinium.)
A system in which you do not have to carry fuel, re: a Bussard ramjet, would merely limit you to your maximum impulse (i.e. when the velocity of the exiting reaction mass equals the velocity of the vessel you can’t get any more thrust out of it); however, there are also some practical limitations; specifically, the ability of your vessel to survive ablation from inertial matter (dust, gas) in the interstellar medium, and the ability of your habitat to insulate the occupants from lethal radiation and (in the case of a Bussard or magnetic containment fusion) strong magnetic fields. It’s not just a matter of getting up to speed, but also not coming apart like a cheap gold watch or reducing your passengers to microwave dinners.
As for traveling to the future, although many people have made farcical (and oft-amusing) asides, the essential point is true; we’re all moving through the future, and in a sense, we’re doing so at velocity c; travelling in an accelerated inertial frame like a fast-moving spaceship doesn’t fundamentally change that; what it does is, in a sense, shift our velocity from the time axis to a time-like path along a spacial path; hence, the spaceman racks up fewer minutes in exchange for more miles.
The one thing about time that you seemingly cannot do, however, is go backwards (or directly “sideways”). You are constrained in the areas of space-time in which you can possibly occupy or even observe, the so-called “light cone” of your future. Why? Uhnuno, but it would make life seriously complex. I mean, if you thought Momento was confusing, just try to figure out the plot of a movie in which the characters go back and change the plot in mid-film.
With regard to downloading consciousness, pleased be advised that this is highly speculative technology. We still struggle with trying to define the essential characteristics of consciousness, and it’s not clear that you can isolate the patterns that comprise consciousness from the physical matrix in which they reside. Memories, concepts, and active neuropsychological activity seem to be controlled by the connections within the network of neurons rather than being stored as static data and instruction codes as per a microprocessor. Desipte with Kurzweil says, I wouldn’t go taking out a second morgage and investing in the IPO of a mind transference startup any time soon.
Stranger’s answer is excellent, but he didn’t mention that at Deadelus speeds of 10% of C or so, the time dialation goes up to 0.5%, or almost two days per year!
Can you imagine how cool that would be? What sorts of amazing new inventions we will have when you get back?
I wonder about that. My guess is that if it were possible, then at the moment of downloading the two ‘personalities’ would start forming their own memories and thus become separate entities. Would this make it less sad if, for example, your human form contracted cancer?
Thanks Stranger for your time.
Emerald Hawk: *“Moon pies. What a time to be alive!” *
