Question game

[Wendark]

Does anybody really know what time it is? Does anybody really care...about time?

[Giving-Small]

Have you ever been to the place where time stands still?

[danger_dan]

does such a place exist?

[heartgirl99]

didn't they just do that?
In movie magic, people and objects can appear or disappear or move from place to place in an instant. Just stop the camera, move things around and start it again. Now, Cornell researchers have demonstrated a similar "temporal cloak" -- albeit on a very small scale -- in the transport of information by a beam of light.
The trick is to create a gap in the beam of light, have the hidden event occur as the gap goes by and then stitch the beam back together. Alexander Gaeta, professor of applied and engineering physics, and colleagues report their work in the Jan. 5 issue of the journal Nature.

A laser beam passes through a "split-time lens" - a specially designed waveguide that bumps up the wavelength for a while then suddenly bumps it down. The signal then passes through a filter that slows down the higher-wavelength part of the signal, creating a gap in which the cloaked event takes place. A second filter works in the opposite way from the first, letting the lower wavelength catch up, and a final split-time lens brings the beam back to the original wavelength, leaving no trace of what happened during the gap. Image: Gaeta lab
The researchers created what they call a time lens, which can manipulate and focus signals in time, analogous to the way a glass lens focuses light in space. They use a technique called four-wave mixing, in which two beams of light, a "signal" and a "pump," are sent together through an optical fiber. The two beams interact and change the wavelength of the signal. To begin creating a time gap, the researchers first bump the wavelength of the signal up, then by flipping the wavelength of the pump beam, bump it down.

The beam then passes through another, very long, stretch of optical fiber. Light passing through a transparent material is slowed down just a bit, and how much it is slowed varies with the wavelength. So the lower wavelength pulls ahead of the higher, leaving a gap, like the hare pulling ahead of the tortoise. During the gap the experimenters introduced a brief flash of light at a still higher wavelength that would cause a glitch in the beam coming out the other end.
Then the split beam passes through more optical fiber with a different composition, engineered to slow lower wavelengths more than higher. The higher wavelength signal now catches up with the lower, closing the gap. The hare is plodding through mud, but the tortoise is good at that and catches up. Finally, another four-wave mixer brings both parts back to the original wavelength, and the beam emerges with no trace that there ever was a gap, and no evidence of the intruding signal.
None of this will let you steal the crown jewels without anyone noticing. The gap created in the experiment was 15 picoseconds long, and might be increased up to 10 nanoseconds, Gaeta said. But the technique could have applications in fiber-optic data transmission and data processing, he added. For example, it might allow inserting an emergency signal without interrupting the main data stream, or multitasking operations in a photonic computer, where light beams on a chip replace wires.

[SillyLoocie]

has everyone signed the entry log this morning?

[electric_viking]

what entry log?

[electric_viking]

there's an entry log?

[Redneck Charger]

Isn't it on the right side as you come in on the third shelve down, on the left side of the shelve under the magazine, to the right on the Time's Magazine, under the popular mechanic magazine to the left of the Reader's Digest, under the playboy?

[SillyLoocie]

Did you not read the rule changes that were implemented today?
Could you please go & sign in at once & please do not delay?
Did you know we now have a dress code that you must always adhere to?
Have you heard that once a week we'll be meeting for beer & cheese fondue?
Will you all please bring your CD's to share with all of us?
Did you know we have no time for pettiness & no tolerance for fuss?
Did you know that meetings sometimes can encourge new ideas & fresh thinking?
Is that not also called networking & is it also linking?
Should we make it pot luck or should we have it catered & served on a platter?
Could you please bring up your suggestions about the things that really matter?

[Redneck Charger]

Did you find the Entry log?

[electric_viking]

Did you not read the rule changes that were implemented today? Was that today?
Could you please go & sign in at once & please do not delay? Does anyone have a pen?
Did you know we now have a dress code that you must always adhere to? do they have enough a$$less chaps to go around?
Have you heard that once a week we'll be meeting for beer & cheese fondue? do you like the new Molson M?
Will you all please bring your CD's to share with all of us? What's a CD?
Did you know we have no time for pettiness & no tolerance for fuss? Is the bouncers' name Gus?
Did you know that meetings sometimes can encourge new ideas & fresh thinking? What happens if everyone is drunk?
Is that not also called networking & is it also linking? is that a hot link?
Should we make it pot luck or should we have it catered & served on a platter? shall i ask the chefs at the Viking hotel?
Could you please bring up your suggestions about the things that really matter? Will they listen with an impartial ear?

[GoJays]

whassup viking dude?

[SillyLoocie]

is it time to get busy?

[GoJays]

busy with what?

[heartgirl99]

not working?