A baseball can do 30 megatons of damage?
You'd think they'd put a warning on them...
Sorry, sci-fi fans: pretty much anyone who's imagined what a near-light-speed spacecraft would look like has got it wrong, because they've forgotten its interaction with photons. Not only that, but according to a couple of scientists working for Raytheon, it doesn't matter whether Einstein's proposition that you'll never …
If it's on Arxiv, it probably could not make it through peer review at a Journal.
You completely misunderstand the nature of Arxiv (and vixra, for that matter), as well as peer review.
And the incentives behind peer review.
Go sit in a corner, dunderhead.
(Damn, I'm too serious again. Time for "venerable ancient bum" icon).
More likely is that the ship will hit a speck of galactic dust, perhaps one micron across. So 10**-18 cubic metres, or ca 10**-15 kg. The rest mass energy is therefore 90 joules, so its kinetic energy at relativistic speeds will be similar.
Suppose there is one such dust grain per cubic metre. At the speed of light, each square metre of the ship will hit 3x10**8 such grains, releasing at least 2x10**10 joules.
The ship will rapidly be reduced to galactic dust.
Some combination of electromagnetic, electrostatic & plasma shields needed I suspect to capture/deflect the particles, plus probably a massive container full of water to absorb that gamma radiation.
Its all just extreme engineering for near light speed travel...
I seem to recall reading, a large number of years ago, that there was a Project Daedelus proposed where we would head off at near-light speed to reach the stars.
If we detected something ahead of us, the craft would send out a fine mist, which, travelling at just below the speed of light, would smithereenerize (is that a word?) anything in it's path.
The craft would then sail serenely through the mist + pulverised remnants and carry on its way.
Isn't the idea of any kind of 'warp' propulsion that it moves a 'bubble' of spacetime rather than the contents, which effectively stay stationary. This is also known as 'frame-shifting'.
This might be bad news for anything in the path of that bubble, which presumably would get either bumped to one side, or torn apart, but the whole notion of accelerating anything to near the speed of light as a means of moving it astronomical distances is obviously a non-starter.
Relativity tells us that this would involve impractically (if not impossibly) vast amounts of energy for one, rising exponentially as you approach C. Your mass would increase accordingly, and time would slow down, which would be a definite problem if you wanted to go to another solar system and still stay in touch with your friends at home, who would all be long dead by the time you get there.
So what these guys are saying, is that if you tried to use an impractical method of transportation, it would be impractical. Nice tautology there...
This is also known as Harry Potter enabling.
Well, yes. Pretty much all SF non-local (inner-system) space travel involves a bunch of magical hand-waving rubbish. Oh, we have warp bubbles, y'see. And deflector shields. And the ship's hull is made of highly compressed fairies.
This is so patently obvious to anyone with a glancing acquaintance with physics that I really am baffled by Chirgwin's "pretty much anyone who's imagined what a near-light-speed spacecraft would look like has got it wrong". I'm not saying there isn't new work in this paper, but the general ideas of high-energy collisions with interstellar matter and blue-shifted photons are pretty common, surely?
I described both of them to my brother in an email many years ago when he was doing some research for an SF story - even did some back-of-the-envelope1 calculations. And I'm neither a physicist nor a spacecraft engineer. If those problems immediately occurred to me, it's vanishingly unlikely that they haven't occurred to a great many SF authors and readers. Who, presumably, ignored them or waved them away in order to get on with the story.
1In those days, still a physical paper object you could jot numbers and equations down on, with a pen.2
2In those days, a physical object you... ah, forget it.
I much prefer the EE Doc Smith solution in Skylark*:
"We're going faster than the speed of light!" says the scientist superhero.
"Doesn't that violate Einstein's Law of Relativity?" asks the plucky sidekick who is there just to ask such questions.
"Yes, but it's happening so Einstein was wrong. I'll figure it out later." answers the scientist.
*Some liberties may have been taken in transcribing the dialogue of this interaction.
I haven't read a sci fi book that relies on warp bubbles in.... ever. Most have either Generation ships, or some kind of lighthugger
Generation ships trundling along between stars might be impractical but they do seem like the only option.
Good to know if a ship is approaching us they'll be visible.
"Good to know if a ship is approaching us they'll be visible."
Would they, would they really? Articles like these fine hope to hostile invasions, but to presume you're enemy will be seen is generally a presumption the loser takes. In less than a hundred years it is only now that we can see most of Earth's deadliest lifeforms using technology. Encode an atom with a virus, send it across the galaxy, watch your enemy wither away. Galatic Bio-Weaponry, beautifully hideous...but effective.
Deflector dish has that exact purpose, to push tiny weeny particles and fotons away from the front of the ship.
The way out is there, altough it is not thoroughly explained how. What I mean is that this was already considered, and a sci-fi coherent answer devised.
"Not only that, but according to a couple of scientists working for Raytheon, it doesn't matter whether Einstein's proposition that you'll never accelerate matter beyond light-speed is right or wrong: collisions with matter will probably rip your spaceship apart anyway, and photons will slow you down."
That is what the Main Deflector is for. "The deflector commonly took the form of a dish-shaped force beam generator containing heavy-duty subspace accelerators at the extreme forward end of the vessel's secondary hull. It performed its primary function by emitting low-power deflector shields to deflect microscopic particles and higher-powered deflector beams and/or tractor beams to deflect larger objects."
What do you mean, Star Trek isn't real?
Or, it isn't part of our human technology.
The universe is a big place. If something is possible in the realm of physics, then it is certainly possible that another intelligent civilization has implemented it, and may still be using it if they didn't die out before we grew to the point where we would observe them using it in our small corner of the universe.
There may be millions or even billions of other civilizations out there, maybe many of the able to travel through space faster than or at some significant fraction of the speed of light. But even if they could travel at some multiple of the speed of light, the distances are so vast that they may never visit anywhere near us.
So just because we don't know how, doesn't mean that many others don't know either - or didn't know when they still existed.
"It's just not real yet."
From a technology standpoint, maybe - though much of it is fundamentally flawed, of course. (Even ignoring the Jar-Jar-verse.)
Once things are down to "it's an engineering problem", the only barrier is economics.
Unfortunately, there's a lot in Star Trek that is far more fanciful than warp drive and inexplicably compatible sexual coupling and reproduction. The idea of some kind of perfect egalitarian society in a post-scarcity, post-conflict, post-need human society is way behind things like deflector dishes in the list of things likely to happen.
Which reminds me - time to take my meds.
No, not the main deflector. That's for weapons fire. You're thinking of the navigational deflector, which while sufficiently powerful to deflect pretty much any 21st-century weapon, isn't capable of deflecting things like photon torpedos with kilogram-scale antimatter warheads.
Hook up the logic circuits of a Bambleweeny 57 submeson brain to an atomic vector plotter suspended in a strong Brownian motion generator (say a cup of hot tea), feed it the improbability for an infinite improbability drive, and away you go. No more mucking about in hyperspace.
Unless you want to deal with Bistromathics, of course
Or like one story I read a long time ago (can't remember its title), the ships were basically large bundles of very thin, needle-like mini-ships. So when they ran into uncharted nebulae, they split up into a cloud of mini-ships and then reassembled themselves afterwards.
Step 1 ) Turn yourself into pure energy.
Step 2) Travel at the speed of light.
Step 3) When arrive at destination, turn yourself from energy back into mass.
Step 4) Profit.
From your your own point of view you 'jumped' from point A to point B.
The only difference is that the place you jumped into was 'shifted' in time by XX.
I prefer Ly Tin Weedle's approach.
The only things known to go faster than ordinary light is monarchy, according to the philosopher Ly Tin Weedle. He reasoned like this: you can’t have more than one king, and tradition demands that there is no gap between kings, so when a king dies the succession must therefore pass to the heir instantaneously. Presumably, he said, there must be some elementary particles - kingons, or possibly queons - that do this job, but of course succession sometimes fails if, in mid-flight, they strike an anti-particle, or republicon. His ambitious plans to use his discovery to send messages, involving the careful torturing of a small king in order to modulate the signal, were never fully expounded because, at that point, the bar closed.
“Our calculation for what an observer on Earth could detect predicts a very unusual signature that is unlikely to be caused by any naturally occurring object in the known universe,"
But there are naturally occurring relativistic objects in the form of cosmic radiation. So why do we not detect such a signature?
Or is this how Raytheon were hoping to detect incoming aliens at UK borders?
Since we don't know anything about its properties, I'm going to decide for the purposes of this post that it will cause all normal matter and photons to bend around it like water going around a ship. Just as scientifically valid as the people saying "deflector dish".
Everyone knows that the big bang started in a parallel universe and burst into ours, where there was nothing to start with. There are an infinite number of parallel universes of different sizes, scales and shapes. To travel great distances in our universe is just a matter of popping over to another universe that has a different scale and temporal flow, travelling a short distance and them popping back into our universe st the distant destination. No near-light speed needed, no deflectors, no cryogenic chambers, no Bussard Scramjets, no wormholes. All you need is a sidestep! We don't have these yet but something else might!
I create a Dark Matter energy field around my space ship, won't that allow me to slip seamlessly through all other particles and photons without interaction?
Ref: article the other day on two galaxies smashing together and DM passing seamlessly through with no interaction.
If you are interested in rocket design and the problems with space travel such as the one mentioned in this article then get yourself to Winchell Chung's Atomic Rockets website:
Prepare to be somewhat depressed when you are repeatedly told "no, you can't do that" however.
Look, I'm trying to navigate at faster than the speed of light, which means that before you see something, you've already passed through it. Even with an IQ of 6000, it's still brown-trousers time.
Okay, the article was about relativistic speeds less than the speed of light, but I still like that line ;-) And it still applies in a way -- by the time you've detected CMBs, at relativistic speeds they've already done their damage.
And there will always be some wacko genius who just goes around them.
For instance: right here on El Reg
So you are smarter than NASA?
No, but I'm not stupid enough to believe that all of physics from the ground up needs to be rewritten because some idiots didn't pay attention in class when error bars were explained.
Amazingly, that kind of thing can be tested anywhere, consistently and we have the math to describe it (even if it did take von Neumann to write the primer). That "NASA" retardation, not so much.
Obviously the technology that we have no real understanding of would be completely baffled by something we do understand... Take that stupid aliens!!! and when they do get here they will be completely overwhelmed by the common cold too, because invading aliens would never see that coming... Or they might invade our water planet when they are in fact allergic to it...
I find it fascinating how 'fizzysists' decide that something isn't possible, because it isn't part of the Standard Model.
Quite apart from the fact that black holes shove the Standard Model up their infinite cavity, it's just ridiculous and very.. well, human, to think that if WE don't know how it's done - then it can't be done.
Space flight was deemed impossible because humans could not possibly withstand the rigors of space.
The Horseless Carriage was deemed impossible because noone could think of how to make something move without oats.
If only these men of science would just try to figure out HOW to do something, rather than spend time telling us why it CAN'T be done, we'd be living on Mars by now...
I calculated just these subjects a decade and change ago.
Blue shifted radiation from the direction of travel would be hard gamma radiation. Re-emission of the absorbed gamma would cause everything from RF through pair production, with plenty of gamma being re-emitted. Exhaust energy would range from IR through RF.
Use a small black hole as a nose cone. Or a confined plasma? Or howabout negative refractive indices? Can you negatively refect gravity (a wave is a wave)? Maybe just fling a wormhole and use it when it's close enough. Pre-ship blobs of quantum entangled matter and then change their state from HQ later to match a desired material form?
Of course it's far easier just to ditch the physical manifestation and send data. That's all everything is at the end of the day. You only need physics for your 'hypervisor'. Then you could use needle-thin vessels and assemble yourself at the end of the journey (whichever of your vessels survives the journey). Maybe use gravity and laser manipulation to induce amino-acid assembly in some remote planet's atmosphere then wait until they're able to pick up the phone and then 'call collect' e.g. the film Contact
I had this discussion with some folks on the LHC forum; the upshot was that the Wow! signal just might have been the radio leakage from dropping out of FTL.
Assuming an Alcubierre-like hypertime drive which uses superdense rotating normal matter in front to locally accelerate the expansion of the Universe for propulsion.
It could be that a Gen 0 (ie Phoenix) FTL might generate a certain RF pulse signature but an entire fleet of ships dropping out would have to do so sequentially or bad things would occur.
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