Near-Light Speeds Dangerous - Do Tell!

[jordan179]

In a good example of an announcement of something which presumably all physicists, and most hard-science fiction writers and fans were already aware, in a condescencing style which implies both that they weren't and that this is some amazing new discovery, comes this article "Warp Speed Will Kill You," by Jeremy Hsu in Space.com (Read more... )

Comments

This is a well known problem...

[zornhau]

Like the "when do the characters take a leak" problem, it's of more interest to non-readers than readers. All stories are selective, and most SF isn't about extrapolation.

Re: This is a well known problem...

[jordan179]

A lot of science fiction just simply assumes near-light or faster-than-light travel, yes. (A good example is L. Sprague DeCamp's "Viagens Interplanetaris" stories, which are scientifically accurate where they bother to go into the science of starflight, which is "not often," because they are more about adventure and anthropology). It's not necessary to do more if the story is not primarily about space travel, but rather about what people do after they arrive at their destinations.

When the technology is described, the presence of some sort of shielding or armor to protect the ship from relativistic-speed collisions is usually mentioned. In fact, even before the problem of interstellar dust and gas was generally appreciated by writers, such protection was assumed to be necessary against micrometeorites (the threat from which was greatly overestimated in the 1920's through 1950's).

Star Trek technology happens to explicitly include super-powerful energy shielding (good enough to easily deflect direct multi-megaton nuclear hits), so

Re: This is a well known problem...

[zornhau]

"Thus fly the Surface-to-Air Missiles of 1810, made of leather, propelled by whale-oil, and ridden by brave young lads who I'm not sure how are to return to Earth safely after they deliver their black-powder shells to the enemy war-balloons! :)"

Oo. Quit writing political blogs and turn that into a novel. Go on. Do it now.

Re: This is a well known problem...

[sianmink]

"Star Trek technology happens to explicitly include super-powerful energy shielding"

not only that, but navigational deflectors that explicitly sweep the space ahead of just the sort of particles that could cause problems.

[montieth]

I thought the whole warp concept involved forming a bubble of space around your ship and moving it through space, ie "warp". Thus removing the relativistic issues AND the problems of interactions with small stellar particles. Plus there's the whole shields thing thats supposed to stop up to nukes next to the ship. Most of the relativistic issues come from high impulse flight.

[jordan179]

Yes. The problem with a warp is that you have to shield the ship against the warp field itself, which apparently would generate storms of exotic particles and bizarre physical conditions. Of course, when we figure out how to make a warp field, the solution to protecting the ship may be obvious, and inherent in the structure of the field itself.

Or it may not be.

I am the Jordan Bassior of 1810, discussing whether or not cast iron or thick fireproofed leather makes a better heat shield for the Space Shuttle :)

[montieth]

Well, there's always that hand-waving away of problems. To whit, the Heisenberg Compensator. But I do seem to recall that the warp field had all sorts of special arrangements, the scollop on the back of the engineering section of the Enterprise being part of the compromises of the structure of the ship accounting for the nature of the warp field.

[seawasp]

The "scallop shell" on the back end of the Enterprise is the shuttle bay door.

The Warp Field was generated by the Nacelles; the forward "antenna" on the front part of the engineering section of the Enterprise was the primary deflector generator grid.

[polaris93]

No doubt the Edelstein of 1810 would be explaining to us that spaceflight was impossible because not even black powder, coal, or even whale oil provides sufficient specific impulse for rocketry. Well, he would if the whole concept of "specific impulse" wasn't developed later in the 19th century than 1810 ...

There's always nonlocality, an aspect of quantum mechanics, that could enable us to avoid the whole problem by means of effectively instantaneous travel (see, e.g., Michio Kaku's Physics of the Impossible: A Scientific Exploration into the World of Phasers, Force Fields, Teleportation, and Time Travel (http://www.amazon.com/Physics-Impossible-Scientific-Exploration-Teleportation/dp/0385520697). If we could do that, we might also be able to shield against penetration by fast-moving particles. Sounds like Mr. Hsu has all the imagination of a pet rock.

[blackhawk101]

I'm a Trekker- everyone knows that the Intertial Dampers on a starship compensate for the speed.

Similar to the problem with transporters- Heisenberg Uncertainty Principle for atoms. This states that one can either know the position or momentum of an atom but the closer one gets to being exact on one makes the other more uncertain. For a transporter to work and reassemble you on the other end both position and momentum MUST be known. Which is why the writers came up with the Heisenberg Compensator within the transporter.

[firstashore]

It isn't: at a mere 10 percent of lightspeed, travel times between most stars would be around 50-100 years

Uh? How do you figure that? At 0.1c, you could get no further than 10 light-years in 100 years, and there are only about 10 stars within 10 light years of Earth, none of which are likely to have planets, much less intelligent life. 10 out of 100,000,000,000 stars in the galaxy, or 0.000000001%, lie within 100 years at 0.1c.

Time dilation is negligible at 0.1c too, so there is no real relativistic advantage.

[jordan179]

Sorry: I worded it poorly. I meant to say "travel time between most stars and the nearby other stars not in their own systems." In other words, the separation between one star and another is usually something on the order of 5-10 LY, and hence a 0.10 C starship would take 50-100 years to cross that distance.

Yes, obviously it would take much longer to reach a star chosen at random out of all the stars in the galaxy!

Actually, it's starting to look as if most stars have planets, though we still have no idea what life those planets may have. Remember that our current technology mostly detects only very large and fairly close planets: many star systems may have no Jovian gas giants (perhaps just a Uranian-sized gas giant and a few terrestrials), or have Jovians out around 40 AU or so.

The Nature of the Fermi Paradox

[jordan179]

It's also occurred to me that you may not be appreciating the precise nature of the Fermi Paradox. The issue is not why the hypothetical technologically-advanced aliens don't fly to us directly from their system of origin. The issue is why we haven't yet been engulfed by their wave of colonization. An alien technological culture might have originated on the other side of the Galaxy and yet eventually expand to the vicinity of (say) Alpha Centauri, assuming enough time and no other factor preventing them.

The reason why it was Fermi who proposed the paradox may have had been more than a little bit to do with his work on atomic energy. Once atomic energy is liberated, even fission, it becomes practical over long time scales to colonize nearby star systems (via generation or seed ship); given fusion and life extension, you're no longer limited to generation or seed ships, because the travel times drop from millennia to decades, and thus the first generation of colonists can expect to still be alive when they reach their destination