Faster than light travel due in 5 years??

[Eclogite]

we can conceivably locate such production facilities in Siberia, somewhere in the northern wastes of Canada, even the Kalahari desert, or Antarctica?

I suggest Washington D.C. That would create a win-win scenario.:doh:

[Pyrotex]

lol Antarctic?...What about in orbit, instead of on the moon - it would make refuelling easier

I wish I could agree with you. :cup: But more than thirty years experience in space has generally proven otherwise. Almost everything is harder in orbit than it is in a nice predictable gravity field. Handling ~H2 is hard to predict, though. You wouldn't have to bias your magnetic fields in the fuel vaults to brace the anti-atoms against a constant gravity tug. There is that. But all our experience repairing Hubble, docking satellites together, putting out Mir fires, trying to refuel fuel tanks, or manage fluids in general--all of it has been extremely tricky.

 

I like Eclogite's suggestion. Put the ~H2 factories in Washington DC. :evil:

[CraigD]

I was privileged to meet the famous physicist (and SF author) Robert Forward back around 1988, in the house of his personal friend, James Oberg (TV authority on the history of the US and Russian space programs).

I am green with envy!

And Dr. Forward just happened to have a presentation that he had just given to the US Air Force and NASA the day before. Over glasses of wine, we discussed his subject: the use of antimatter in space travel. Fascinating!!

 

It has been many years, but I have recalled that evening many times, and so here is what I reconstruct from memory…

Pyro’s recollection seems pretty close to the figures Forward gives in his 1995 book “Indistinguishable from Magic”, a book I was so taken with, I repurchased it in electronic (html) format. From that book:

In a study I carried out for the Air Force Rocket Propulsion Laboratory, I showed that if an antiproton factory were designed properly by engineers, instead of by scientists with limited budgets and in a hurry to win a Nobel prize, the present energy efficiency (electrical energy in compared to antimatter annihilation energy out) could be raised from a part sixty million to a part in ten thousand or 0.01%, while at the same time, the cost of building the factory could be substantially lowered compared to the cost of the high precision scientific machines. From these studies, I estimated the cost of the antimatter at ten million dollars per milligram. This may sound like a lot, but at ten million dollars per milligram, antimatter is already cost effective for space propulsion and power. At the present subsidized price of a Space Shuttle launch, it costs about five million dollars to put a ton of anything into low Earth orbit. Since a milligram of antimatter produces the same amount of energy as twenty tons of the most energetic chemical fuel available, then a milligram of antimatter costing ten million dollars would be a more cost effective fuel in space than twenty tons of chemical fuel costing ten times as much.

…

Antimatter at the present cost of ten trillion dollars per milligram has already been proven cost effective for scientific experiments to win Nobel prizes. Antimatter at a hundred million dollars per milligram would definitely be cost effective for unmanned probe missions to the rings of Saturn and manned missions to Mars. When the cost of antimatter starts to drop below ten million dollars per milligram, then many new applications come to the fore, for now antimatter is cheaper in energy delivered to orbit than any chemical fuel, and possibly even cheaper than nuclear fuel.

 

Where will we get the energy to run these magic matter factories? Some of the prototype factories will be built on Earth, but for large scale production we certainly don't want to power these machines by burning fossil fuels on Earth. There is plenty of energy in space. At the distance of the Earth from the Sun, the Sun delivers over a kilowatt of energy for each square meter of collector, or a gigawatt (1,000,000,000 watts) per square kilometer. A collector array of one hundred kilometers on a side would provide a power input of ten terawatts (10,000,000,000,000 watts), enough to run a number of antimatter factories at full power, producing a gram of antimatter a day.

Dr. Forward suggested placing the facilities on the Moon, since 1 gram of ~H2 that explodes is equivalent to about a 10 kiloton atomic bomb.

I don’t recall any mention of this in IfM – rather, in one of its illustrative fictional stories (the book alternated between non-fiction and fiction chapters), he describes a 21st century scene in which passengers on a Earth-to-L-4 aerospace plane are able to faintly see the antimatter factories nestled between 2 panels of a 30 x 300 km, 10 TW Earth orbiting solar arrays that power them, having earlier in the trip seen the abandoned remains of the first specialized antimatter factory in the desert near Edwards AFB.

 

Forward seems to have imagined the transition from present-day, research-oriented accelerators, which can produce antimatter with an energy efficiencies of about 10[math]^{-8}[/math], to specialized “factories” with efficiencies of about 10[math]^{-5}[/math], as happening in "generations", with successive facilities being replaced by larger and more efficient ones, informed by engineering lessons learned from their predecessors. Given that building a particle accelerator on Earth’s surface is a challenging engineering task now, the first generations will almost certainly be built here, and likely powered by a mixture of sources, including poor old fossil fuel.

 

Forward hints that the ultimate antimatter factories may be part of huge solar power arrays orbiting the sun within the orbit or mercury to maximize their power/area ratios.

 

Nowhere does Forward, or any other serious technologist of whom I’m aware, suggest that antimatter would permit faster-than-light travel, nor that the technology will be usable for more spaceflight by the year 2012, only that it will allow much greater slower-that-light travel than is possible with present-day rocket technology.

[DryLab]

I have to agree with the "it ain't gonna happen" folks.

[DougF]

I have to agree with the "it ain't gonna happen" folks.

At lest not in 5 years. but it would be great wouldn't it.

[DryLab]

Oh yes; it would be great. But I would be happy just to see communication at faster than light. Its more than 10 years now that seemed promising with entangled photons, but I haven't seen the breakthrough yet :lol:

[DougF]

Oh yes; it would be great. But I would be happy just to see communication at faster than light. Its more than 10 years now that seemed promising with entangled photons, but I haven't seen the breakthrough yet :lol:

Ditto: I wounder what the next big breakthrough will be.

[DryLab]

I wounder what the next big breakthrough will be.

Maybe in SETI. If there is an advanced civilization whose understanding of physics far exceeds our own they might try and communicate at FTL. And if modulating polarity in entangled photons works, then maybe we should be de-modulating polarity to try and find a signal :lol:

[TheBigDog]

I think that for the fastest travel we will discover how to break down into a more basic form, and then reform. Imagine something like a transporter beam, where a person is converted into a stream of photons, beamed to a receiver, and then reconstructed. The transport speed would be C, the deconstruct, reconstruct would be the slow part.

 

Feasible with inanimate objects, very complicated with life forms. Beware of flies in the soup.

 

Bill

[CraigD]

Imagine something like a transporter beam, where a person is converted into a stream of photons, beamed to a receiver, and then reconstructed.

This scenario is especially appealing combined with 3083. Being converted into a signal to get somewhere is less onerous if you’re a signal to begin (and end) with.

 

Of course, you’ve still got to get some sort of spacecraft there, before you can begin beaming people between stars. Starwisps are an attractive possibility.

[Jay-qu]

The only prob I have with these teleporter ideas is this - would you be the same person coming out the other end? or do you die and get a reconstucted clone at the other end? Im tipping towards the latter :S

[CraigD]

The only prob I have with these teleporter ideas is this - would you be the same person coming out the other end? or do you die and get a reconstucted clone at the other end?

People have been puzzling over this one for at least 1900 years – Plutarch asked it in the form of the Ship of Theseus paradox, while Hofstadter, Dennet, and others asked it persistently and with intensity in 1981 in ”The Mind’s Eye”. I’ve been focused on the puzzle since about then. Before I read that book, I gave the question only passing thought – in retrospect, I think that a childhood spent watching Star Trek characters get beamed hither and thither without ontological complication inured me to the paradox, perhaps setting me up for my current, intuition-informed position on the question.

 

That position is that it’s a question that presumes the existence of a semantic null – that is, the existence of an attribute of “what-it-is-ness” that can get lost or found when a thing is transformed, replaced a piece at a time, taken apart and put back together, copied, etc. In my unprovable philosophical opinion, if a computer model of a person, or a taken-apart-and-put-back-together manifestation of a person, behaves sufficiently like that person that even the most careful objective and properly blinded observer couldn’t tell the copy from the original, the original and the copy are the same person.

 

I suspect there’s a more-than-usual chance that I’m wrong about it, though, in the sense that it may prove insurmountably impossible to upload a person into a computer, or convert them into a stream of photons then reconstruct them from it.

[Jay-qu]

Thats just thing, it would be completly indistinguisable, but yet made from different atoms. You believe that it would be the same 'person' what about conciousness? Take this as an example - what if the device somehow malfunctioned (or was made to do it on purpose) and the copy at transmitting end was not 'destroyed' so that there are now 2 identical bodies. Does this persons conciousness experience through both bodies? My guess, which im sure most people would agree, is in the negative.

 

Perhaps a new thread to discuss this in more detail?

[Qfwfq]

Its more than 10 years now that seemed promising with entangled photons, but I haven't seen the breakthrough yet

And I doubt you will.

 

There's no way of choosing which state of either particle will be observed, so it can't be used to send information.

[DryLab]

There's no way of choosing which state of either particle will be observed, so it can't be used to send information.

I have to agree, I don't see how either. But the entangled photons seem to communicate at FTL speeds, so it would seem that you could simply modulate polarity (state) in one photon and demodulate the other. But it don't work.

[Qfwfq]

...so it would seem that you could simply modulate polarity (state) in one photon and demodulate the other.

It would seem. :doh:

[Tormod]

There's no way of choosing which state of either particle will be observed, so it can't be used to send information.

 

Well...I'd be more comfortable with "There's (currently) no way of...". :doh:

 

I read in PC Magazine (where else?) about research being done on quantum computers, where they are studying the possibility of using "knots" of qubits to create a "topology" - the point being that this "topology" would remain when the qubits collapse into real-world data. The reason why they need something like this is basically that only very basic calculations can currently be done with quantum computers, since the quantum state of the cubits is unstable.

 

It's not unthinkable that entangled particles could be used to convey information. I do however agree that currently it seems impossible.