Space combat, travel, living...

[maackey]

Maackey you should listen to relativity. It's well verified theory :) And It says no- object with mass cannot travel faster than light (unless space itself is distorted) and yes time dilates. Moving close to speed of light you could travel across visible universe in your life time.

Its well tested and time dilatation even has to be taken into account for stuff like GPS satellites.. If you want example from objects really moving close to speed of light, take particle experiments, time slows for them (like decay time) and mass increases for them exactly as calculated - and we propel some bigger material stuff at close-to-c speeds too, like lead atoms.

It has been a while since I've done basic relativity physics and I might be making stuff up (yes, I really do need to go back and study this stuff), but its very difficult to wrap my head around mass *actually* increasing the faster you go. How do you know that it *actually* increases as opposed to it just looks like it is increasing?

[Licho]

Simplest way to send data to build our bodies is to send frozen embryos :) It's actually been suggested many times in sci-fi. Just send embryos + robotic caretakers and information to make them grow into more or less normal humans and establish civilization.

[Licho]

Maackey if mass does not change then it would violate mass-energy equivalence (yes that basic E=mc^2) and break all that follows from that.

You cannot just take one thing from the theory without breaking the well tested rest.

We think it changes for real, because for example objects with known rest mass moving at such speeds really do impact with energy which can only be explained by their increased mass. It can also be tested using astronomical objects moving at such speed and warping space (causing gravitational lensing) to extend supposed to be caused by increased mass.

[Panda]

Simplest way to send data to build our bodies is to send frozen embryos :) It's actually been suggested many times in sci-fi. Just send embryos + robotic caretakers and information to make them grow into more or less normal humans and establish civilization.

That's why we need cryptobiosis, so we can make aliens that are actually humans.

[Teutooni]

It has been a while since I've done basic relativity physics and I might be making stuff up (yes, I really do need to go back and study this stuff), but its very difficult to wrap my head around mass *actually* increasing the faster you go. How do you know that it *actually* increases as opposed to it just looks like it is increasing?

Energy equals mass (times c squared). Which means increased energy equals increased mass. Most of baryons masses consist of energies keeping quarks together - the rest is masses of quarks themselves afaik. Quarks have been observed (not sure if this is verified) to have a fine structure suggesting their mass is caused by some internal energies. I guess you could say there is no mass, only energy.

Simplest way to send data to build our bodies is to send frozen embryos :) It's actually been suggested many times in sci-fi. Just send embryos + robotic caretakers and information to make them grow into more or less normal humans and establish civilization.

Better yet, send robotic caretakers with strong AI to establish the civilization and forget the embryos.

[Johannes]

Though I don't see why would we send robots or embryos to random faraway places, what's the point? Not a very useful way to spend resources...

[Panda]

Simplest way to send data to build our bodies is to send frozen embryos :) It's actually been suggested many times in sci-fi. Just send embryos + robotic caretakers and information to make them grow into more or less normal humans and establish civilization.

Better yet, send robotic caretakers with strong AI to establish the civilization and forget the embryos.

Maybe the robotic caretakers would enslave the human race, causing the humans to run off with the robotic technology, escape that planet, and live on earth as normal khaki colored people, just like the rest of us.

[Argh]

Honestly, I suspect that we're going to be theoretically able to solve the issues of travel any year now. Whether it's using information theory to change the states of things far away through local changes, somebody creating a breakthrough technology for dealing with cryogenic damage to biology (all those exotic methods of cooling may have other uses) nanotech that can keep cells from triggering aging and deal with radiation damage or whatever.

The real issue is that it won't get pursued. I think we'll wait until things get worse on Earth before deciding to make it a priority as a species.

This will be the Robot Generation, where robotics finally becomes broadly ubiquitous and the labor market goes through some really wrenching problems (which may be the end of us as a species, frankly), but I'm willing to bet that Man on Mars remains a political slogan, or at best, a media stunt.

[Mav]

Combat - ballistics, directed energy, missiles. Unless I'm missing something these are pretty much your options of damaging other space vessels. bullets travelling long distances could be dodged (or deflected with electro-magnets?) depending on the circumstances, lasers can be reflected, and missiles can be shot down

Lasers powerful enough to actually damage a ship can't be reflected. I know you're thinking "but a mirror reflects light and a laser is just light!"
No.
The energy density of lasers like this are so great that they simply destroy anything they hit, including mirrors.

[TradeMark]

Simplest way to send data to build our bodies is to send frozen embryos :) It's actually been suggested many times in sci-fi. Just send embryos + robotic caretakers and information to make them grow into more or less normal humans and establish civilization.

Yeah, although, i was thinking even more simplier way: really simple/strong cells with some DNA. Just shoot them everywhere, some of them will grow, eventually.

[Gota]

hmm maybe we will eventually find some gates left by a long extinct civilization that allow us to travel from one point in the universe to others in a heartbeat.

[HeavyLancer]

Yeah, although, i was thinking even more simplier way: really simple/strong cells with some DNA. Just shoot them everywhere, some of them will grow, eventually.

You mean Panspermia? We might just be a result of that.

Colonisation is interesting - a one-way trip, probably without a living person aboard until you get to the planet. Perhaps you could 'seed' a planet with terraforming machines and wake the people up when it is ready?

On the other hand, space combat is a pretty shitty thing. The only viable zone for combat is around a planet and it's a quickdraw showdown with smart missiles. Politically though, what do you have to gain? If you have a planet to yourself, or better still a whole star system to your self, what is the point of fighting someone who has millions and billions of kilometres between them and you?

[hoijui]

maackey: your problem seems to be your understanding of "what really is" and "seems to be".
from the POV of a "resting" observer, the fast moving thing seems to have increased mass, and it really has this increased mass. from the POV traveling on that fast thing, it does not seem to have increased mass, and really does not have (there never is a difference between these two). so on impact (if i am right ), the two things act on each other with their upped masses; it is not just one of them having that, because physically, there is not one resting and one moving fast. they just have speed relative to each other (i guess this makes no sense, language wise, but you may get what i mean (german is much better really! )).

[PicassoCT]

Simplest way to send data to build our bodies is to send frozen embryos :) It's actually been suggested many times in sci-fi. Just send embryos + robotic caretakers and information to make them grow into more or less normal humans and establish civilization.

Americanos on Yellowstone? Here comes Lichie...

[Licho]

Yeah lol, I liked revelation space series.

[Teutooni]

Though I don't see why would we send robots or embryos to random faraway places, what's the point? Not a very useful way to spend resources...

Knowledge and exploration? More living space? Natural resources? Conditions on earth worsening? I'm pretty sure you could come up with a few uses for another habitable planet within reasonable distance (Gliese 581g?).

[Neddie]

Sending the equipment and resources to permit maturation, as well as the resources to create a sustainable environment and perhaps educate the product is also prohibitive in that scenario. However, it is more feasible than sending mature humans.

[maackey]

really excellent explanation

What really gets me is that from the point of view of the "moving" object, everything stays the same; mass, length contraction, time dilation, it will never change from the perspective of that object. (which is apparently what I failed to convey)

@Mav: What about crystallized gas (or some other materials) to refract and spread the laser beam to reduce its energy density? I know lasers with sufficient power can melt mirrors. It isn't really what I was thinking when I mentioned reflecting - more of a "deflect what you can, absorb what you can't". I don't know the numbers, I'll have to look them up later. Should be interesting though.

http://www.ru.nl/hfml/research/levitation/diamagnetic/ -- also for anyone interested this is a pretty neat article about magnetic fields + levitating stuff. (like frogs)

[Licho]

"Space" will appear completely different from the perspective of person moving at light speed.
Its as if space was moving at light speed.

[PicassoCT]

It turns into a redshifted and blueshifted tunnel, with x-rays boiling the cockpit of your spaceship- also supersmall dustparticles.

I would still hit it with the speed of light.