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TheMoMan
Member # 1659
 - posted January 05, 2012 04:37
Now this could be fun.

Time cloaking?

Back in August 2011 Ham radio operators had the ARISSat-1 satellite deployed from the ISS. Here is the last known telemetry prior to burn up.

ARISSat-1 "SK"
 
The Famous Druid
Member # 1769
 - posted January 05, 2012 07:39
Add an entry to your list of oxymorons: "Fox News Science Reporting"

I went a-googling, it turns out the 'Time Lens' is a device for fibre-optic communications.

As far as I can tell, it works by adding a small delay to a light beam by passing it through some material with a high refractive index (remember your high school physics? light travels more slowly through glass). Add the right amount of delay, and you can reverse the phase of the light, which, apparently, is a useful thing to do when processing optical signals.

The whole Harry Potter/Museum Heist thing is just the usual Fox spin, they could have just given us the facts, but where's the fun in that?
 
TheMoMan
Member # 1659
 - posted January 05, 2012 07:55
I was thinking of the old subliminal clips showing things from the Snack stand at a Cinema
 
Xanthine
Member # 736
 - posted January 05, 2012 12:05
The media outlets are excited about a new paper that came out in Nature this week. I'm still trying to figure it out (this is so far out of my field it's ridiculous for me to even try) but the authors do state that the approach TFD is talking about is NOT what they did. They did something else. Something I'm not sure I understand yet. But the net result is that they buried a signal within a signal in such a way that, when the cloak was on, this other signal was 10-fold weaker when it hit the detector on the other end than it was when the cloak was off. In other words, information was inserted and extracted without little trace left...and with some improvement, no trace left. No trace. As in you do not perceive it. The information was not detected and therefore it no longer exists. Think about the implications for cryptography.
 
dragonman97
Member # 780
 - posted January 05, 2012 16:45
quote:
Originally posted by Xanthine:
[...]No trace. As in you do not perceive it. The information was not detected and therefore it no longer exists. Think about the implications for cryptography.

That sounds completely awesome.

However, the xkcd-reading /.er in me feels compelled to cite:
http://xkcd.com/538/

(It would be perfect unless someone suspected that the data was travelling /somehow/, in which case the wrench comes into play.)

ETA/PS: Here's an arstechnica story on the Nature article:
http://arstechnica.com/science/news/2012/01/optical-setup-helps-researchers-hide-an-event-from-time.ars
(It should have more/less truthiness than Fox "News" (depending on how you measure things).)
 
Xanthine
Member # 736
 - posted January 05, 2012 16:59
That's the spooky part, dman. If they do it right, you'd never even know the data was there. It's not some slight-of-hand like the tricks currently used - the way a good time cloak works, you literally can't detect a parasitic signal. When kreziserb made his first attempt at the paper last night he had to put it down and walk away. The implications freaked him out...and he doesn't scare easily. Once I understood what I was reading, I got a little nervous too.

But it was a 40 picosecond event under very tight conditions. Nothing with real-world applications. Just a cool if freaky finding.

ETA: actually, believe it or not, Fox didn't do such a bad job on this one. But the arstechnica article is the best popular version of the story I've seen so far. I also read the dumbed-down review version Nature published alongside the paper and it was about as rough as the paper itself.
 
dragonman97
Member # 780
 - posted January 05, 2012 17:42
quote:
Originally posted by Xanthine:
That's the spooky part, dman. If they do it right, you'd never even know the data was there. It's not some slight-of-hand like the tricks currently used - the way a good time cloak works, you literally can't detect a parasitic signal.[...]

By 'suspected,' I don't mean via a perceived trace, but the knowledge that some data should be transmitted, which raises the question "How did it get there?" For instance, if you know that confidential data is getting from Site A to Site B, but cannot account for transmission of that data (no evidence of an encrypted data stream even), it might raise questions. Similarly, with TrueCrypt, if someone uses its super-duper 'volume within a volume' that is nearly impossible to locate, *but* you're a ne'er-do-well and know s/he has financial data that you can't find, you're going to ask "Where are the financial records? I know you have them somewhere!"

That doesn't stop the science from being amazing...I'm just saying that the absence of something might actually call attention to it.

P.S. Something that's a bit unclear to me - can this thing actually be reversed? My first read of the arstechnica piece suggests that the time window can be opened and something placed inside, but my scientifically limited interpretation didn't quickly suggest that it could be seen later (when one knows how to get at it). I suspect it's possible, but difficult -- and I'd love clarification on that from a cleverer person than me.
 
TheMoMan
Member # 1659
 - posted January 05, 2012 17:48
Remember the news story about a timing error was causing researchers at CERN to claim that they observed photons moving faster than light, some body that knows the Boson's Mate Higgs knows how to manipulate the timing signals.
 
Xanthine
Member # 736
 - posted January 05, 2012 18:41
MoMan, when the FTL neutrino story hit the news I talked to a physicist buddy about it. He told me that this happens every couple of years or so - someone at an accelerator makes a boo-boo and sees something that isn't there. But, interestingly, the last I heard, the scientists at CERN weren't sure what their mistake was this time (assuming it was a mistake...cue up the Twilight Zone music).

Dman, to notice an absence you need to know there should be something there and to notice a presence you need to know something shouldn't be there. Smart cryptographers know this. But even if your enemy is sloppy or stupid and reveals that they have a secret communications channel, how in the world would you be able to find these signals? If someone figured out how to implement this technique on the frequencies used by cell phones, how the hell would anyone figure out which phone or even which network the cloaked signal is on?
 
dragonman97
Member # 780
 - posted January 05, 2012 19:13
Easy answer: The $5 wrench...as wielded by your Everyday Henchman (TM). [Wink]
 
TheMoMan
Member # 1659
 - posted January 06, 2012 07:19
While on the topic of hiding data:

Possible invisible Trojan

I still believe that in person with a teller banking is better
 
Ugh, MightyClub
Member # 3112
 - posted January 06, 2012 22:28
Whoa. Turns out this is a Cornell discovery -- that's my neighborhood!

That doesn't help me understand it any better, though.
 
TheMoMan
Member # 1659
 - posted January 08, 2012 08:44
It gets even weirder

Photonics

Wired's take on the story.

IO9

Try wrapping your head around this.
 
maswan
Member # 269
 - posted January 12, 2012 13:05
quote:
Originally posted by Xanthine:
MoMan, when the FTL neutrino story hit the news I talked to a physicist buddy about it. He told me that this happens every couple of years or so - someone at an accelerator makes a boo-boo and sees something that isn't there. But, interestingly, the last I heard, the scientists at CERN weren't sure what their mistake was this time (assuming it was a mistake...cue up the Twilight Zone music).

Being in reasonably close proximity to CERN, the reason they went public is because they spent half a year going over all their calculations and models and measurements and couldn't figure out why.

Since then they've even done another round of measurements to get rid of some other potential sources of systematic errors with the same result.

Almost certainly there is a mistake somewhere, but what it is is not known (and a bunch of pretty bright people have butted their heads against it too).

Luckily it shouldn't be hard to place it firmly in the "some kind of mistake" bin since they are busy setting up similar experiments both in JP (KEK) and US (Fermilab).
 
GrumpySteen
Member # 170
 - posted January 12, 2012 13:58
And that's how it's supposed to work. When you find a result that you can't explain, you ask for help finding the explanation. At worst, you find out you did something dumb. At best, you discover something new that advances our knowledge of how the universe works.

 -
 
TheMoMan
Member # 1659
 - posted January 12, 2012 20:13
However time varies, were these experiments done during the day or night as the tangent velocity through space changes from Noon to Midnight.
 




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