Scientists claim warp drive is possible

[Cancer]

Re: Scientists claim warp drive is possible

 

If you converted all the mass of the universe to energy and converted it with 100% efficiency' date=' into an accelerative force propelling one atom, would it still be limited to light speed, or would the fact that the rest of the mass of the universe no longer exists "break" our system of physical constants?[/quote']

 

Now you're bumping up against problems with thermodynamics, but the remaining matter would still be tied to the limit: "The speed of light is constant in all frames of reference."

[Cancer]

Re: Scientists claim warp drive is possible

 

So you know, university Physics is essentially three years of this discussion among like-minded enthusiasts.

 

Done with supercomputers, access to the textbook collections of five continents and thirty languages.

 

On four hours sleep a night.

 

With no sex.

 

You're not going to find the loophole these guys missed.

 

Repped. And it's much, much worse than this. Insert "And they think that finding a loophole in all this will get them sex." under the "no sex" line. Now you see the magnitude of the situation.

[L. Marcus]

Re: Scientists claim warp drive is possible

 

. . . Such strange people . . .

[megaplayboy]

Re: Scientists claim warp drive is possible

 

Now you're bumping up against problems with thermodynamics' date=' but the remaining matter would still be tied to the limit: "The speed of light is constant in all frames of reference."[/quote']

 

Well, since the speed of light has been calculated with 9 significant digits of precision AFAICT (well, that's the official figure for it, anyway), how much energy would it take to accelerate a charged particle(of the minimum mass we can measure accurately) to within 8 significant digits of light speed(IOW, 0.99999999 c)?

 

My freshman physics is rusty, and I no longer have the Lorentz equations memorized.

[Maur]

Re: Scientists claim warp drive is possible

 

How to Build a Time Machine - Paul Davies

http://www.amazon.com/Build-Time-Machine-Paul-Davies/dp/0142001864/

 

And Paul Davies research group - http://cosmos.asu.edu/

[Cancer]

Re: Scientists claim warp drive is possible

 

The LHC, currently in commissioning, will make protons (rest mass energy of 938 MeV) with 7 TeV total energy and collide them. If I have done my arithmetic right, that's a velocity of 0.999999991 times c. That's about 2.7 m/s less than c.

[megaplayboy]

Re: Scientists claim warp drive is possible

 

The LHC' date=' currently in commissioning, will make protons (rest mass energy of 938 MeV) with 7 TeV total energy and collide them. If I have done my arithmetic right, that's a velocity of 0.999999991 times c. That's about 2.7 m/s less than c.[/quote']

 

Well, that sounds fast enough to see if relativity holds up at near-luminal speeds.

[Captain Obvious]

Re: Scientists claim warp drive is possible

 

If you converted all the mass of the universe to energy and converted it with 100% efficiency' date=' into an accelerative force propelling one atom, would it still be limited to light speed, or would the fact that the rest of the mass of the universe no longer exists "break" our system of physical constants?[/quote']

 

If there's only one atom, then relatively speaking, it's not moving.

[Cancer]

Re: Scientists claim warp drive is possible

 

If there's only one atom' date=' then relatively speaking, it's not moving.[/quote']

 

Well, since there's no other matter against which to compare it, that's one possible answer.

 

The radiation in the Universe provides another possible frame.

[Kristopher]

Re: Scientists claim warp drive is possible

 

Yes.

 

Hrm.

[Zeropoint]

Re: Scientists claim warp drive is possible

 

If you think this stuff make sense, you're probably missing something.

 

But I had a thought: we're all sitting here describing how any FTL travel equals time travel which means causality violation therefore FTL travel can't exist . . . but the scientists quoted in the first post say . . . it can?

 

Granted, they're saying that it would take an energy density that is not physically possible . . . hmm, is that equivalent to saying "it's not possible after all"?

 

Maybe I shouldn't be trying to think about this when I should have been in bed two hours ago.

[megaplayboy]

Re: Scientists claim warp drive is possible

 

Well, if FTL isn't possible, and travel from one star system to another is unlikely to ever be cost-efficient (bringing enough resources to settle or terraform another planet requires enormous amounts of energy to propel through space, and at 1-10% of light speed the journey will take decades, centuries or even millenia), wouldn't that suggest one reason we've never made contact with extraterrestrial life?

 

They just crunched the numbers and gave up trying.

[Comic]

Re: Scientists claim warp drive is possible

 

Repped. And it's much' date=' much worse than this. Insert "And they think that finding a loophole in all this will [u']get[/u] them sex." under the "no sex" line. Now you see the magnitude of the situation.

 

.. sex with green-skinned hyper-evolved beings who worship them as gods for discovering FTL.

[Nyrath]

Re: Scientists claim warp drive is possible

 

Well, if FTL isn't possible, and travel from one star system to another is unlikely to ever be cost-efficient (bringing enough resources to settle or terraform another planet requires enormous amounts of energy to propel through space, and at 1-10% of light speed the journey will take decades, centuries or even millenia), wouldn't that suggest one reason we've never made contact with extraterrestrial life?

 

They just crunched the numbers and gave up trying.

Well, the problem with the Fermi paradox is that one-hundred-percent of the alien races gave up trying. Don't you think that at least one would be insane enough to do it anyway?

 

There are ways around the problems:

http://www.projectrho.com/rocket/rocket3aj.html

 

The ship can bring all the people and livestock as frozen fertilized ova, plus a mechanical incubator and computer controlled robots.

 

If you can make a Bussard ramjet work, you can get your ship up to speeds where relativity will slow down the aging of the crew.

 

If your medical technology has advanced enough you can put the crew into suspended animation. If it has advanced even further, the crew may be functionally immortal.

[megaplayboy]

Re: Scientists claim warp drive is possible

 

Well, the problem with the Fermi paradox is that one-hundred-percent of the alien races gave up trying. Don't you think that at least one would be insane enough to do it anyway?

 

There are ways around the problems:

http://www.projectrho.com/rocket/rocket3aj.html

 

The ship can bring all the people and livestock as frozen fertilized ova, plus a mechanical incubator and computer controlled robots.

 

If you can make a Bussard ramjet work, you can get your ship up to speeds where relativity will slow down the aging of the crew.

 

If your medical technology has advanced enough you can put the crew into suspended animation. If it has advanced even further, the crew may be functionally immortal.

 

Well, accelerating a 1000 ton (10^6 kg) spaceship up to 0.1% lightspeed, then slowing it down again for landing, would still require a lot of energy(9 x 10^16 joules(sloppy and a bit inaccurate on my part, but that's the kinetic energy at full speed, doubled), plus the energy required for sustaining minimal maintenance conditions for the multi-millenia trip to a nearby star system.

The yearly electricity generation of our whole planet is around 6 x 10^19 joules per year, so that's still a pretty substantial energy cost, even for one modest-sized slow-moving interstellar ship. Go up to 10 percent of lightspeed(100x the energy, before factoring relativistic effects), with a bigger ship to hold all that fuel and resources, and the energy costs are enormous, compared to the energy resources of the one known inhabited planet in the universe (which are on the order of about 10^23 joules or so, if you used all the fossil fuels and uranium-238 available here).

I guess a civilization could be crazy enough to attempt it, but it wouldn't take more than a few failures to whittle down even the number of crazy space-exploring civilizations.

[Zeropoint]

Re: Scientists claim warp drive is possible

 

You don't have to make it all in one trip. As I understand it, our Oort cloud kind of blends in with Alpha Centauri's . . . we could simply expand slowly, creating lots of small habitats/colonies out there, harvesting resources, and just slowly expand over into the next star system.

 

There's also the possibility of uploading consciousness into computers and sending them out . . . remove the limits of frail flesh altogether!

[Basil]

Re: Scientists claim warp drive is possible

 

It takes (literally) infinite energy to accellerate an object to the speed of light. You would have to use some value greater than infinity and "infinity" doesn't work that way. If you can add to it, it either wasn't infinite to begin with or it was a type of infinity that is (by definition only) a "smaller" sort of infinity.

 

Example: All even integers is an infinite set. All integers is also an infinite set, but includes "more" integers (the odd ones) than the previous set. Both sets are still infinite and therefore (technically) equal.

 

I'm afraid not. (Oy, transfinite numbers. Like this thread wasn't complicated enough!)

 

To put it simply: Mathematicians do recognize types, or kinds, or "levels", of infinity. The way one level is distinguished from another is simple (in theory); if both sets of numbers can be put in one-to-one correspondence, they are the same level of infinity.

 

What does that mean? Well, if I can describe a way to associate all the members of, say, "the even numbers" with all the members of, say, "the integers," and vice versa, then they are in one-to-one correspondence, and are the same "level" of infinity.

 

And, of course, I can. Every integer, doubled, is an even number, and every even number, halved, is an integer. So, they're the same "level" of infinite.

 

BTW, all rational numbers can (in a difficult way I can't recall right now) be put in one-to-one correspondence with the integers, so they're the same kind of infinity. You have to get to irrational numbers to get the next "level" of infinite.

 

BTW, the various transfinite numbers are symbolized in math with the Hebrew letter Aleph; Aleph-null (for zero), Aleph-one, Aleph-two, etc. The integers (and all "equally" infinite sets of numbers) are Aleph-null. IIRC, no more than Aleph-three or Aleph-four have been proven as distinct "levels" of infinity.

[SSgt Baloo]

Re: Scientists claim warp drive is possible

 

I'm afraid not. (Oy, transfinite numbers. Like this thread wasn't complicated enough!)

 

To put it simply: Mathematicians do recognize types, or kinds, or "levels", of infinity. The way one level is distinguished from another is simple (in theory); if both sets of numbers can be put in one-to-one correspondence, they are the same level of infinity.

 

What does that mean? Well, if I can describe a way to associate all the members of, say, "the even numbers" with all the members of, say, "the integers," and vice versa, then they are in one-to-one correspondence, and are the same "level" of infinity.

 

And, of course, I can. Every integer, doubled, is an even number, and every even number, halved, is an integer. So, they're the same "level" of infinite.

 

BTW, all rational numbers can (in a difficult way I can't recall right now) be put in one-to-one correspondence with the integers, so they're the same kind of infinity. You have to get to irrational numbers to get the next "level" of infinite.

 

BTW, the various transfinite numbers are symbolized in math with the Hebrew letter Aleph; Aleph-null (for zero), Aleph-one, Aleph-two, etc. The integers (and all "equally" infinite sets of numbers) are Aleph-null. IIRC, no more than Aleph-three or Aleph-four have been proven as distinct "levels" of infinity.

 

Thanks for the clarification (it's been a while since I've learned what little I know about transfinite numbers). My point, however, was that to accelerate a particle of any mass whatsoever to the speed of light would require all the mass and energy in the universe (provided, of course, that our universe is truly infinite) including all background energy and the mass of the particle itself, which would then be one or more photons travelling at exactly the speed of light. Of course, since there would be no frame of reference to measure the velocity or location of that photon (or photons) it's "speed" would be irrelevant. The photons (if there are more than one) would be travelling at C relative to one another, but photons always travel at C. If there was one photon only, there would be no frame of reference to measure by, and the exercise would be pointless and destroy a perfectly serviceable universe. Don't do it. I keep my stuff here!

[Captain Obvious]

Re: Scientists claim warp drive is possible

 

In re: FTL = time travel, how does quantum entanglement enter into it? Couldn't that be used for FTL communication, which, apparently, would allow someone to act on information "before" it was transmitted to them?

[DusterBoy]

Re: Scientists claim warp drive is possible

 

Of course, we could be like 19th Century physicists explaining why nuclear power would be "impossible", since before 1890, it seemed like the foundations of physics and thermodynamics had been securely laid . . .

 

And then look what happened - X-Rays (which Lord Kelvin dismissed as a hoax), relativity, quantum mechanics, the splitting of the atom.

 

Or look at Friar Roger Bacon, writing in the 13th Century: "Instruments may be made by which the largest ships, with only one man guiding them, will be carried with greater velocity than if they were full of sailors. Chariots may be constructed that will move with incredible rapidity without the help of animals. Instruments of flying may be formed in which a man, sitting at his ease and meditating on any subject, may beat the air with his artificial wings in the manner of birds . . . as also machines wich will enable men to walk at the bottom of the sea . . ."

 

Every single one of those predictions has come true, but at the time of writing, if you had told anyone that Bacon was right, they would have dismissed you and him as madmen.

 

And that may be the entire point. To quote Sir Arthur C Clarke - "The real future is not logically foreseeable."

 

We may not get it in our lifetimes, or in our grandchildren's lifetimes or in the lifetimes of their grandchildren - or it may come before the end of this century.

 

One thing is certain sure though: FTL will not be developed by people who have already decided that it is impossible.

[Nyrath]

Re: Scientists claim warp drive is possible

 

Of course' date=' we could be like 19th Century physicists explaining why nuclear power would be "impossible", since before 1890, it seemed like the foundations of physics and thermodynamics had been securely laid . . .[/quote']

Yes, that's the standard "but maybe a scientific breakthrough..." argument. This approach has problems.

 

Again, postulating such a thing is perfectly fine for a Star Hero campaign, but in the real world that's not the way to bet.

[megaplayboy]

Re: Scientists claim warp drive is possible

 

How much energy would be required to propel maybe a dozen 1000 ton exploratory slower than light vessels at 1% of lightspeed?

My impression, based on what I posted upthread, is that this is well beyond the energy capacity of our current tech.

Even at 1/1000th of lightspeed, we're still talking about a lot of energy. And we wouldn't get results for millenia. Even at 10% of lightspeed it would take decades or centuries to explore nearby systems.

 

Not only does sci fi need FTL, it needs some form of super high energy tech and/or a means of going that fast without expending vast energy.

[Nyrath]

Re: Scientists claim warp drive is possible

 

In re: FTL = time travel' date=' how does quantum entanglement enter into it? Couldn't that be used for FTL communication, which, apparently, would allow someone to act on information "before" it was transmitted to them?[/quote']

Well, as far as the physicist is concerned, FTL communication is every bit as bad as FTL travel. FTL communication is a species of time travel as well, according to relativity.

 

And no, it is impossible to use quantum entanglement for FTL communication. Both theoretically, and in all experiments to date. Believe me, they've tried. There is a Nobel prize and a patent worth more than Bill Gate's bank account awaiting the inventor of FTL communication.

 

With quantum entanglement, you'll get a string of essentially random numbers at the transmission point and a string of essentially random numbers at the destination point. Only by comparing the two sets of numbers can the message be decoded. And the only way to get the first set of numbers to the destination is to send them by radio or otherwise non-FTL.

 

If you could send the numbers by some other FTL communication method, you could get rid of the quantum entanglement junk and just use the other method.

[Nyrath]

Re: Scientists claim warp drive is possible

 

How much energy would be required to propel maybe a dozen 1000 ton exploratory slower than light vessels at 1% of lightspeed?

My impression, based on what I posted upthread, is that this is well beyond the energy capacity of our current tech.

Even at 1/1000th of lightspeed, we're still talking about a lot of energy. And we wouldn't get results for millenia. Even at 10% of lightspeed it would take decades or centuries to explore nearby systems.

 

Not only does sci fi need FTL, it needs some form of super high energy tech and/or a means of going that fast without expending vast energy.

 

Relativistic effects are only noticable above 14% lightspeed, so we can just use the plain vanilla kinetic energy equation:

 

Ke = 0.5 * M * V^2

 

A 1000 metric ton ship would be 1,000,000 kilograms.

1% lightspeed is about 3,000,000 meters per second.

 

So the energy required is about 4.5 x 10^18 joules. Looking at your hand-dandy Boom Table, you can see this is about 1,000 megatons or 1 gigaton.

 

Actually 2 gigatons, since presumably you want your ship to slow down to a stop at your destination.

 

But you've got another problem, you've run full tilt into John's Law. This means that if your exploration ship happens to impact on, say, the Earth, it will be the equivalent of a 1 gigaton nuclear bomb. And you want a dozen of these. I'd include a remote-control self-destruct, in case the pilot goes insane and decides to annihilate the western hemisphere.

[megaplayboy]

Re: Scientists claim warp drive is possible

 

Relativistic effects are only noticable above 14% lightspeed, so we can just use the plain vanilla kinetic energy equation:

 

Ke = 0.5 * M * V^2

 

A 1000 metric ton ship would be 1,000,000 kilograms.

1% lightspeed is about 3,000,000 meters per second.

 

So the energy required is about 4.5 x 10^18 joules. Looking at your hand-dandy Boom Table, you can see this is about 1,000 megatons or 1 gigaton.

 

Actually 2 gigatons, since presumably you want your ship to slow down to a stop at your destination.

 

But you've got another problem, you've run full tilt into John's Law. This means that if your exploration ship happens to impact on, say, the Earth, it will be the equivalent of a 1 gigaton nuclear bomb. And you want a dozen of these. I'd include a remote-control self-destruct, in case the pilot goes insane and decides to annihilate the western hemisphere.

 

9x 10^18 joules per ship, times 12 ships. That's 1.08 x 10^20 joules. This, according to wiki, is about 150% of the planet's current electricity generation, about 1/400th of the planet's total fossil fuel energy reserves as of 2003, and about 1/2000th of the planet's total U-238 reserves using fast reactor technology.

 

So, I would regard the energy requirements as non-trivial for a 21st century technologically advanced civilization.

If we came close to utilizing the total energy from the sun that hits the earth every year, that gets us up to around 5.5 x 10^24 joules. At that rate, using 0.1% of that energy output on space travel, we could send out 500 or 600 such ships every year, or perhaps just 5 or 6, traveling at 10% of lightspeed. Even so, it begins to clarify why we haven't seen any space arks.