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Interstellar Hydrogen Prevents Light-Speed Travel?
garg0yle writes "As if relativity wasn't enough to prevent us traveling at light speed, Professor William Edelstein of the Johns Hopkins University School of Medicine is now claiming that the interstellar hydrogen, compressed in front of the ship, would bring the journey to a shocking end. 'As the spaceship reached 99.999998 per cent of the speed of light, "hydrogen atoms would seem to reach a staggering 7 teraelectron volts," which for the crew "would be like standing in front of the Large Hadron Collider beam."'"
That's what the deflector array is for.
Don't take life so seriously. No one makes it out alive.
And I was just about to get into my 99.999998% lightspeed spaceship.
After reading the article (yeah, I know...) tow thought spring to mind...
/., I expect you all to forgive me for using the present tense here [grin]
1) Warp drive doesn't posit a traditional "go-very-fast-through-normal-space" type of spacecraft engine - it warps[*] space-time (hence the name!) in front of and behind the spacecraft - see here for an explanation. The spacecraft itself is sitting in a bubble of normal space, possibly even at rest.
2) Um, ramjets, anyone ?
Seriously, any number of sci-fi authors have covered this problem in enormous detail over the last few decades
Simon
[*] And because this is
Physicists get Hadrons!
Let's just hope the engine controls aren't made by Toyota, or it'll be hitting that speed whether the crew want or not.
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
put a hydrogen-atom-splitter on the bow of the ship, they'll just get cut in half and fall out of the way.
"hydrogen atoms would seem to reach a staggering 7 teraelectron volts," which for the crew "would be like standing in front of the Large Hadron Collider beam."
Wow, free energy!
Free Martian Whores!
Guess we'll just have to go at 99.999997% of the speed of light then.
. . .to GET to .99999998 c, this is unlikely to be a concern. And if you have the effectively-infinite energy to move a ship at this speed, providing sufficient shielding should be a trivial exercise in additional hand-wavium. . . .
Spacetime is curved, so even if the ship is traveling at 15mph, it reaches its destination in a time indicating FTL travel. The actual distance traveled is much shorter, though.
This is the stuff you should already know before you apply to Starfleet.
All you have to do is navigate around the hydrogen atoms.
I don't think anyone seriously contemplating relativistic or FTL travel expects to be physically accelerated to such speeds. After all, if stationary interstellar hydrogen is effectively hitting you at teravolt levels, it means that every particle in your body (and the ship) has actually been accelerated to velocities equivalent to the particles in the LHC beam. Not bloody likely. We need warp drive, subspace, wormholes, or something else to solve the problem, not ridiculous conventional acceleration.
- Michael
I'll bet that would sting.
"The average reporter we talk to is 27 years old......They literally know nothing." - Ben Rhodes
So, what he's saying is that the interstellar hydrogen density will limit us to no more than about 9600 light years nonstop at a continuous 1g acceleration/deceleration.
Given that even a matter/antimatter conversion drive would require about 116,000,000 tons of reaction mass (half antimatter) for every ton of payload, it would seem that we're going to be hitting a great many limits long before this particular limit begins to be meaningful.
"I do not agree with what you say, but I will defend to the death your right to say it"
This is what happens http://lhc-machine-outreach.web.cern.ch/lhc-machine-outreach/components/beam-dump.htm
how long until
What does this guy know about space travel? He's a prof at a medical school, FFS. This is rocket science, not brain surgery!
Sure, it seems infinitely fast, but it's really not going to get us anywhere all that interesting in a single lifetime.
For the personal traveling at that speed, it most certainly WILL be a single lifetime. In fact, the trip would seem to them to be instantaneous.
"His name was James Damore."
Interstellar travel is fundamentally an economic paradox — ignoring, of course, such fantasies as Warp drives.
Sending a Shuttle-sized craft to Alpha Centauri in a matter of years would require roughly the current total energy consumption of humanity.
Only when our civilization advances to the point that we harness a significant portion of the Sun’s total energy output would the energy budget for interstellar travel approximate the same proportion of the energy budget we spend today on interplanetary missions.
One can suggest “sleeper ships,” but building mechanical devices that will survive thousands of years is as hard a problem as throwing them across light years of distance. Any gas will leak out of any container in such a timeframe, and no plastic or rubber seal would last a fraction of the time necessary. The next thought is to provide power to the ship during the long journey, but you need as much total energy as for getting there fast — and, if you can comfortably survive for millennia in interstellar space, why even bother with stars in the first place?
Oh — and the Fermi Paradox applies especially well. Assume that it takes even ten thousand years to colonize a remote solar system, and the entire galaxy would have been overrun by now if a colonizing civilization had started in the terrestrial Jurassic period.
Interstellar travel makes for great space opera, but it has no more bearing on reality than unicorns and dragons.
Cheers,
b&
All but God can prove this sentence true.
Didn't E.E Smith talk about this years ago in the Lensman books. I'm pretty sure the Galactic Patrol moved on tear-drop shaped warships over their original spheres purely because their intertialess drive allowed them to move so fast the the occurrences of interstellar hydrogen atoms began to act on the hulls as friction and slowed them down.
There's an old saying, nothing focuses the mind like a firing squad. When faced with imminent death, humans are famously adept at coming up with novel solutions to complex problems. To that end, I propose we gather a collection of prominent physicists and place them in a ship capable of accelerating to near-light speed over a period of some years. Put locks on the controls so that they are unable to halt or alter the acceleration, then inform they have X years to come up with a way to avoid being smashed to death by interstellar gasses. Either they come up with a solution and are all saved, or they perish in a fiery ball of glory. Either way, they'll probably all have high schools named after them.
God invented whiskey so the Irish would not rule the world.
They already figured this out nearly a hundred years ago.
In fact, erosion by interstellar matter (both hydrogen and dust) was a major plot element in Arthur C. Clarke's 1986 novel The Songs of Distant Earth.
A while back, at the old 1994 Planetary Society conference on Interstellar Flight, I had a paper proposing a plasma erosion shield to protect an interstellar spacecraft-- I ought to dig that one up and put it on the web somewhere, but New Scientist ought to know about it, since they mentioned it in an article back in 1995.
http://www.geoffreylandis.com
Do not try to dodge the atoms - that's impossible. Instead, only try to realize the truth: there are no atoms.
Thereby increasing, almost infinitely, the improbability of any FTL technology - thusly ensuring success for a system that harnesses improbability as a motive power.
"Speaking the Truth in times of universal deceit is a revolutionary act." -- George Orwell
...
Since most of the time the LHC is down that doesn't seem like a big problem :-p
Ok, big fan of the LHC, but just had to say it
B: Star Trek ain't real.
But science keeps coming up with things based on it: cellphones, PDAs, netbooks, flash memory, etc. Everyone needs inspiration from something.
http://science.slashdot.org/comments.pl?sid=177080&cid=14696574
The density of interstellar space is about one atom per cubic centimeter [hypertextbook.com]. If the spaceship were going near the speed of light (3 x 10^10 cm/sec), it would be hit by 3 x 10^10 relativistic particles per cm^2/sec. This is about the equivalent of one Curie [wikipedia.org] per cm^2, which would kill a human and cripple any electronics on board
A very heavy magnet could deflect the protons, but the neutral atoms would be unaffected by the magnetic field.
Since most of the time the LHC is down that doesn't seem like a big problem :-p
Not to mention, does that comparison mean anything to anyone else? I've never stood in front of the LHC personally and don't know anyone who has. I can -assume- it wouldn't be healthy, but... well, it doesn't really ring home with me. It's not like "Oh shit, interstellar FTL would be like standing in front of the LHC? Well the last time I did that, I got horrible hemorrhoids. Good to know. Note to self: do not drive faster than light to a nearby solar system."
How hard would it have been to make a more visceral if less accurate car metaphor. "99.999998 percent of the speed of light through hydrogen atoms would be like trying to drive your car at 90 miles an hour into a concrete wall." ...although I haven't done that either recently...
Is this it, Dr. Landis?
http://www.islandone.org/Settlements/MagShield.html
Magnetic Radiation Shielding: An Idea Whose Time Has Returned?
Geoffrey A. Landis
Presented at the Tenth Biennial SSI/Princeton Conference on Space Manufacturing
May 15-19, 1991, Princeton, N.J.
posted with permission of author
The real reason interstellar travel will never happen is the time in the security line with TSA would approach infinity for that sort of trip.
Actually you are missing something very important in your maths: relativity. It doesn't take much shorter to get to the destination from the perspective of someone on earth, but the tale is different for the people on the spaceship. The distance to the destination shrinks.
Sagan talks about this in Cosmos. If a theoretical spaceship accelerated constantly, it could traverse the entire universe in a mere 50 years -- but by the time it returned earth would be long gone.
Conceptually -- the universe has no "size" for a photon in a perfect vacuum. From the point of view of this theoretical photon, it is created in a distant star and intersects with your eye instantaneously. From our point of view it could take millions of years.
Considering that mass is what prevents light-speed travel (as well as the density of the medium being travelled through), that implies an interesting relationship between space-time and the higgs boson.
The universe is stranger than any fiction.
Like all pain, suffering is a signal that something isn't right
One of those classic complaints against popular sci-fi is that the ships are always pretty and "aerodynamic" (well, mostly, anyway) and that there's no need for this in a vacuum... Well, there you go, one good reason to have aerodynamic space ships. :)
Making spaceships sleek was a key part of making them fast in the Lensman books for more or less the same reason. (Smith's goofy FTL drive idea negated the mass of the ship, allowing the ship to instantly accelerate to a speed where thrust equaled drag)
Bow-ties are cool.
If you accept as givens that 1) intelligent life develops with relative ease, and 2) interstellar travel is technologically feasible, then what the Fermi paradox is telling you that we shouldn't expect to be the first, as that outcome is quite unlikely. The universe has been in business for almost 15 billion years, which is plenty of time for lots of civilizations to have developed. Since it's manifestly not true that the universe has been overrun with space-faring aliens, one or both of the premises must be false. My personal bet is that they both are, but I'm pessimistic that way.
That sounds like you're kind of proposing using air resistance to make your car go faster. Which, of course, doesn't make much sense. It's not that the hydrogen has 7 teV of kinetic energy - it's that your SPACESHIP has that energy, and is colliding with hydrogen which is (basically) at rest. You can't extract energy from the 'at rest' hydrogen atoms, because they don't have it. What would happen is that your collision with those molecules would likely destroy your ship (massive hull heating, until you get vaporization; possibly sub-atomic reactions, not sure), and those atoms that passed through the ship would destroy your flesh.
There is a concept, called the Bussard Ramjet, which suggests using some sort of 'scoop' to gather some of the hydrogen in front of and around the ship, and using some of your kinetic energy to compress/heat the hydrogen until you cause fusion, so that you can actually extract energy from the 'at rest' H, but that is fusion energy, not kinetic energy. Once you've released the fusion energy, you could try to direct it away from the ship, thereby getting a net increase in kinetic energy. But, again, the key point there is the energy is being extracted from Hydrogen fusion.
Not to mention, does that comparison mean anything to anyone else? I've never stood in front of the LHC personally and don't know anyone who has.
Talk to this guy.
Yo dawg, I heard you like the Ackermann function, so OH GOD OH GOD OH GOD
As an added benefit, the polarity of such a deflector could be reversed to solve all sorts of problems that might crop up.
Michael Reed, freelance tech writer.
Lasers in front to plasmatize the hydrogen, huge magnetic fields to move the plasma to the REAR of the ship, where a "virtual" burn chamber (really just magnetic fields) captures the plasma. Another mag field keeps the antimatter from touching anything, and gradually releases anti-atoms to the furnace. BOOM mega boost. Easy to shield mere energies if you can do all that trickery with fields. Certainly possible - just very, very hard.
'Once scientists, even the dim-witted social scientists, get muzzled, the Western Civilization is finished.' - oldhack