FTL?

JimmyB27 · Aug 17, 2007

http://www.telegraph.co.uk/earth/main.jhtml?xml=/earth/2007/08/16/scispeed116.xml

A pair of German physicists are claiming to have broken the speed of light. Reminds me of that guy who claimed he'd made a perpetual motion machine that could provide infinite supplies of free energy, and took out a full page ad in The Economist to announce it to the world.
So, are the laws of physics more like guidelines, or are these guys just crackpots? I guess we'll have to wait and see...

Adam Israel · Aug 17, 2007

I read it yesterday. Until it's peer-reviewed, though, it's just another claim.

Julie Worth · Aug 17, 2007

Here's more on that, reprinted from the New Scientist. With a bit of hand waving, it can be explained away.

oscuridad · Aug 17, 2007

quantum tunnelling isn't exactly the same as ftl - it just looks like it is.

Popeyesays · Sep 3, 2007

oscuridad said:
quantum tunnelling isn't exactly the same as ftl - it just looks like it is.

Tunneling is a great 'gimmick' for SF, though. I used it as the basis of FTL travel that isn't 'travel' at all since nothing every has velocity in the first place.

Regards,
Scott

benbradley · Sep 3, 2007

The article says these are particles moving faster than light. I dunno but we already have information being transferred at FTL with quantum entanglement (aka the EPR paradox), and infornation is, as far as the laws of relativity are concerned, the same as particles in that it is deemed impossible to travel faster than light.

I predict that by the time people land on Mars they will use a "quantum radio" that transmits and receives instantly instead of with the several minutes' delay that current speed-of-light technology has. And the use of quantum radios may well have an effect on the universe that we won't anticipate...

ChunkyC · Sep 4, 2007

benbradley said:
I predict that by the time people land on Mars they will use a "quantum radio" that transmits and receives instantly instead of with the several minutes' delay that current speed-of-light technology has. And the use of quantum radios may well have an effect on the universe that we won't anticipate...

Great, the ducet tones of a Simon Cowell-created boy band wending their way through the quantum sub-structure of the universe....

Screw global warming, if that comes to pass, we're effing DOOMED. :tongue

small axe · Sep 7, 2007

benbradley said:
I predict that by the time people land on Mars they will use a "quantum radio" that transmits and receives instantly instead of with the several minutes' delay that current speed-of-light technology has. And the use of quantum radios may well have an effect on the universe that we won't anticipate...

I remember a chilling comment in Orson Scott Card's SPEAKER FOR THE DEAD where he suggests just that -- the protag wonders whether their starships' drives aren't killing other planets' and races' suns or something, unknown to Earth humans. I think ST:TNG had an episode there too, that the warp drives were creating corridors of dead space etc.

Scary thoughts, the possible effects of technology ... here on the threshold of Global Warming, where our burning the previous dinosaurs and their forests for fuel may make us the NEXT species to follow the dinosaurs into extinction?

On our racial tombstone it may read: "They traveled faster than they thought"

JimmyB27 · Sep 7, 2007

small axe said:
Scary thoughts, the possible effects of technology ... here on the threshold of Global Warming, where our burning the previous dinosaurs and their forests for fuel may make us the NEXT species to follow the dinosaurs into extinction?

I wonder if, in 65 million years time, we'll all be powering the next civilisation's cars?

She_wulf · Sep 7, 2007

Odd question, speed of light

If you are traveling at the speed of light and holding a laser, then would the laser photons be traveling at twice the speed of light?

Pthom · Sep 7, 2007

Only in science fiction, She wulf. According to Einstein's General Theory, at the speed of light, everything becomes light--or energy, which is almost the same thing. The problem occurs when one attempts to envision 'traveling' at the speed of light. Once you attain the speed of light, you cease to be you, and your laser not only ceases to emit photons, it ceases to be a laser.

As I understand the ideas presented above, "Faster Than Light" is really "instantaneous relocation" if you will--no time is involved in the transfer of an object from point A to point B. Maybe this is possible. Maybe it's been done, even. But I am pretty sure the objects that change locations by such means are extremely tiny--massless, even--like photons themselves.

Julie Worth · Sep 7, 2007

She_wulf said:
If you are traveling at the speed of light and holding a laser, then would the laser photons be traveling at twice the speed of light?

If you approach the speed of light while pointing the laser in the direction you're moving in, the photons become blue shifted relative to everyone else, but they still travel at the speed of light. And if you point it in the opposite direction, the photons will be red-shifted, but again, they still travel at the speed of light. Your laser itself can get close to the speed of light, but can never actually get there. What's not usually appreciated is that you can travel "faster than the speed of light" in one sense, if you go by ship time. This is because of time-dilation. For instance, you could traverse the galaxy in a day, as measured by a clock on your ship, but it will still take a hundred thousand years by a clock back home.

Deirdre · Sep 7, 2007

What Julie said, and this is basically how radar detectors work: measuring very small blue/red shifts.

She_wulf · Sep 7, 2007

Pthom said:
...
As I understand the ideas presented above, "Faster Than Light" is really "instantaneous relocation" if you will--no time is involved in the transfer of an object from point A to point B. Maybe this is possible. Maybe it's been done, even. But I am pretty sure the objects that change locations by such means are extremely tiny--massless, even--like photons themselves.

But...but... I read in Scientific American (or another such magazine) that they had accomplished "faster than light" through the use of a focal lens.

Two paths of photons were split and sent down identical paths, except one path was interrupted by a lens that actually manipulated the particle's shape to be an oval rather than spherical, resulting in the elongated photon 'hitting' the target end first.

Popeyesays · Sep 7, 2007

Benbradley,

Check out the last Nova show. It postulates the Global Dimming (the proliferation of soot and other particles in the upper atmosphere causing less sunlight to reach the surface of the earth) has probably saved us from the real total effects of global warming. By the year 2050, if the partiulate emissions around the world drop significantly we coulod find ourselves with tempratures 18 degrees fahrenheit above 1975 average tempratures.

Regards,
Scott

Pthom · Sep 8, 2007

She_Wulf:

But...but...a photon is still a massless sub-atomic particle. In terms of practical "travel" whether below, at, or faster than the speed of light, photons don't qualify as "things." Do they? And anyway, if the measure of traveling faster than the speed of light is to be stretched from the normal state to an elongated one, I'll give up my line in the queue to someone a lot more adventurous than me.

Ordinary_Guy · Sep 15, 2007

She_wulf said:
But...but... I read in Scientific American (or another such magazine) that they had accomplished "faster than light" through the use of a focal lens.

Two paths of photons were split and sent down identical paths, except one path was interrupted by a lens that actually manipulated the particle's shape to be an oval rather than spherical, resulting in the elongated photon 'hitting' the target end first.

She... there have been half a dozen experiments where superluminal phenomena have been observed. In each and every one, though, there is always a catch of one sort or another where the guys publishing backpedal faster than Deion Sanders to assure us that the luxon wall is still impenetrable.

That may yet change, but it'll take a fundamentally different understanding of physics to take advantage of it (sort of how Newtonian physics gave way to relativistic physics).

Ordinary_Guy · Sep 15, 2007

Pthom said:
...As I understand the ideas presented above, "Faster Than Light" is really "instantaneous relocation" if you will--no time is involved in the transfer of an object from point A to point B. Maybe this is possible. Maybe it's been done, even. But I am pretty sure the objects that change locations by such means are extremely tiny--massless, even--like photons themselves.

In what I've seen in relation to observing superluminal propagation, there are definitely measured grades of speed past c.

When you get into "instantaneous" it gets sticky. Personally, I think "spooky action at a distance" is really the achilles heel of relativity (and probably a door – or at least a window – into the next phase of understanding physics). A little thought experiment to shake your trust in mathematics that uses "infinite" as a constant:

Take Object X in Location A. Push the button. Object X ceases to exist in Location A and now is located in Location B. Instantaneous travel, right? This would've required "infinite" speed, right?

Sort of.

True "infinite" speed would actually place Object A in all locations simultaneously.

...'Course, were at the point where the theoretical is playing more in the philosophical but heck, that's what this all about, right?

Popeyesays · Sep 17, 2007

Pthom said:
She_Wulf:

But...but...a photon is still a massless sub-atomic particle. In terms of practical "travel" whether below, at, or faster than the speed of light, photons don't qualify as "things." Do they? And anyway, if the measure of traveling faster than the speed of light is to be stretched from the normal state to an elongated one, I'll give up my line in the queue to someone a lot more adventurous than me.

One can observe the same phenomenon with electrons transfering position within the shells of the atom.

Electrons have mass.

Regards,
Scott

Pthom · Sep 17, 2007

Popeyesays said:
Electrons have mass.

Of course they do. But not very much, individually.

For that matter, photons have mass, too. Just not "at rest" mass. An explanation of this aspect of photons is here.

And even if it were neutrons exhibiting such behaviour, my contention stands. We are not sub atomic particles, nor can we travel on them. And I may be a doubting Thomas, but it seems unlikely we'll ever be able to move conglomerations of sub atomic particles (atoms and more) in such a manner and have everything remain exactly the way it started out once it arrives there.

But I could be wrong. It would be very cool if I am.

MargueriteMing · Nov 10, 2007

She_wulf said:
If you are traveling at the speed of light and holding a laser, then would the laser photons be traveling at twice the speed of light?

Well, in theory you cannot accelerate mass to the speed of light. So, let's say you are travelling at .99C. Because of time dilation, time is passing much slower for you, from the point of view of a stationary observer. When you turn on the laser, a stationary observer sees the light slowly pulling away from you. However, your perceptions are slowed down. While 1 second passes for the outside observer, .01 seconds passes for you, or something like that. So, by the time you have perceived 1 second passing, the laser light has travelled the distance away from you that you would have expected, if you were stationary, so from your point of view, light is still moving at same speed of light as you would perceive it as an outside observer. This is part of what relativity is all about.

Julie Worth · Nov 10, 2007

MargueriteMing said:
This is part of what relativity is all about.

It is, in fact, the second postulate of special relativity. Just a postulate, not a law or anything.

If you want to see the reasoning, look here.

FTL?

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