Kolya on 12/1/2012 at 09:09
Jetpacks and beam guns!
Papy on 12/1/2012 at 12:29
Quote Posted by demagogue
It is a cloaking device in the sense that the whole idea of a cloak metaphor is that some area is getting constructed around an object that light can't or doesn't get into to detect it.
That's not what this is about. It's not about light in general (as in ambient light) it's about one specific laser beam. More importantly, that way of manipulating the laser beam could never be extrapolated to light in general.
As for semantics, if I change the firmware of a security camera so it doesn't record what will happen between 8am and 9am... Would you call that new firmware a "cloaking device"?
demagogue on 12/1/2012 at 17:59
First, this isn't really a debate about what's actually going on, just about a definition for some scifi thing, which makes it a kind of nerdy non-debate. :)
But while we're on a roll, I'll be precise how I was thinking about it...
Necessary & sufficient conditions for something to be a "cloaking device" IMO:
- thing there
- light there
- device manipulate light
- light no touch thing
- light still touch everything else around
- thus: cloak of total luminal non-interaction around only the thing
Quote Posted by Papy
That's not what this is about. It's not about light in general (as in ambient light) it's about one specific laser beam. More importantly, that way of manipulating the laser beam could never be extrapolated to light in general.
So they had to meticulously construct the context around it to work by excising all the other light except for this laser beam, and precisely controlling the beam and the thing getting "cloaked" (having to shoot it exactly into the gap) on top of that. Science does that. There's still a cloak of total luminal non-interaction constructed around the thing in that frame. If you flooded it with ambient light, or even scaled it up the tiniest bit, there wouldn't be. If you like to have necessary & sufficient conditions for your definitions, though, then it meets them in that bounded context. It's a cloaking device for losers stuck in special-laser-in-a-special-fiber-optic-tube land, but no where else. Which is to say it's a very *bad* cloaking device that doesn't really do what it's supposed to to do the job it's doing.
Quote:
As for semantics, if I change the firmware of a security camera so it doesn't record what will happen between 8am and 9am... Would you call that new firmware a "cloaking device"?
There isn't a cloak around it of total luminal non-interaction, so no. Light is still bouncing off things; it's just not being recorded.
Papy on 16/1/2012 at 05:00
Quote Posted by demagogue
First, this isn't really a debate about what's actually going on, just about a definition for some scifi thing
What? Since when? I certainly consider this subject is about real science, not about some crazy sci-fi stuff. Not that I don't like the craziness of sci-fi (as a teen, I read most of the sci-fi section of my local library), but science is incredibly interesting by itself and it certainly deserve a serious thread once in a while.
Quote Posted by demagogue
There isn't a cloak around it of total luminal non-interaction, so no. Light is still bouncing off things;
And in what way is that different from the experience those researchers made? Is it because they turned off the light? There wasn't a cloak around it of "total luminal non-interaction" and light was still bouncing off things (I'm sorry, but turning off the light except for one laser beam doesn't count). Again, this experiment was not about "temporal cloaking" it was about modifying one laser beam in a specific way so that, in theory, it wouldn't interact with a specific object at a specific time. The same cloaking effect could have been done far more efficiently using three mirrors. Or simply a wall of brick and second laser to recreate another similar beam. They called it "temporal cloaking" simply because they were manipulating speed instead of path. Woopidoo.
Seriously, did you read the analogy of the train they gave? Because that's exactly what they were doing. Do you think that creating a space between the front half of the train and its rear half is about creating a "temporal cloaking" device? The fact is they did not change the time property of a particular space, they just modified one laser beam. Calling this "temporal cloaking" is simply dishonest. To me, it's borderline fraud. And that's my problem with this whole thing. They act like unscrupulous salesmen, not like scientists.
I know I should probably take this more lighthearted, but science is already plagued with people who deliberately lie. We, as a society, end up wasting money on stupid things like homeopathy because of them. Indirectly, they take resources away from honest scientists. Worse, they discredit honest scientists. So how about we stop encouraging dishonest people? How about we give headline space to real science instead of some guys who do a useless experiment but who are good with marketing?
DDL on 16/1/2012 at 10:42
You didn't actually read the paper, did you?
Ok, let's take the train analogy (not mentioned in the paper itself, as far as I can see). One: this is not a train. It's light. Light (unlike trains) is not made up of discrete carriages you can just uncouple from each other. It's a continuous beam. What they've demonstrated here is essentially a technique for briefly "cutting a laser beam in half", which is quite impressive, really. While the actual applications for making a 'cloak' are very limited (and they actually say this, too: "Although spatial cloaking is still limited in angular acceptance, wavelength, polarization and efficiency, we have shown that we can deplete a probe wave and restore it to its original state after the event."), this technique opens up a whole mass of spacial and temporal possibilities for photon-based processes such as computing: you can effectively have two beams of light passing through each other, but only interacting on demand. They also state this in the paper.
Now. Regarding your other points, you have to remember that science is not, on the whole, a profit-making enterprise. Sure, a fuckton of things that are now hugely successful can trace their origins back to science, and indeed this (along with hopefully a degree of general altruism and wonder about the world) is why science gets funded at all. Most research is not funded by the profits of that research, it's funded by governments, trust funds, charities and so on. There is far more demand than there is actual money, so to get money you have to really sell your research.This means that those better at marketing their findings do indeed tend to be more successful than those less adept. This is basically unavoidable.
Secondly, science is often reported by science journalists, who (while generally possessing a science background) cannot be expected to be experts in every field they report on. Also, quite a few of them are actually pretty stupid, I find. Plus, they have to come up with ways of communicating things that are often highly-technical cutting-edge research, to people with say...a science GCSE. Add to that, lazy journalists often consult press releases rather than primary sources, so they're actually reporting on reporting: they're using an already obfuscated 'sexed up' report as if it were a primary source.
Buzzwords get jumped on. Often misinterpreted. Shit happens. Deal with it.
And accusing the authors of "borderline fraud" when you haven't apparently even read the fucking paper is ever so slightly harsh, I'd say.
Papy on 16/1/2012 at 22:17
Quote Posted by DDL
You didn't actually read the paper, did you?
The paper? No, I only read 4 different articles on it. I didn't feel like paying $32 to read a paper about something which has very little interest. Just out of curiosity, did you read it?
Quote Posted by DDL
It's light. Light (unlike trains) is not made up of discrete carriages you can just uncouple from each other. It's a continuous beam.
Do you really want me to explain to you what light is? Because it seems to me you don't really know what it is.
Quote Posted by DDL
a technique for briefly "cutting a laser beam in half", which is quite impressive, really
No, it's not impressive. It's something which is done regularly in a lot of applications.
Quote Posted by DDL
this technique opens up a whole mass of spacial and temporal possibilities for photon-based processes such as computing: you can effectively have two beams of light passing through each other, but only interacting on demand.
Oh for fuck sake, just use different wavelength.
Quote Posted by DDL
you have to remember that science is not, on the whole, a profit-making enterprise.
Yes, and as you said those who are better at marketing get the money. How about we raise our voice to help those who are better in science than marketing?
DDL on 16/1/2012 at 22:25
I can't believe I've found yet another thing to argue endlessly with fucking papy about. Jesus wept.:(
For the record, yes: I read the paper. It was...dry, but then it IS a physics paper.
And as for deciding who gets the funding..how exactly does one decide that? Who detemines which science is 'better' than the others? The people most qualified to make that judgement are, after all, the very same people competing for the money.
And we can't let you decide it, coz you're fucking idiotic.
Azaran on 17/1/2012 at 00:25
Papy, science is actually underfunded compared to many other things. I saw a video a while back where this researcher was commenting on science and creationism in the US, and he was lamenting how creationist groups have almost infinite resources at their disposal (which they gleefully waste on building "creation museums" to fool the gullible, make dvd's and websites and write books to spread their message, and lobby politicians to make laws in their favour). He was saying if science had just a quarter of the cash creationists have, we'd be far more advanced by now, and cancer might have been cured already.
Papy on 17/1/2012 at 04:37
Quote Posted by DDL
And we can't let
you decide it, coz you're fucking idiotic.
So you claimed that "a technique for briefly cutting a laser beam in half is quite impressive", which in reality is something done with very simple means... and yet I'm the one who is idiotic? Do you realize that you are making a fool of yourself?
OK. I have some doubts. When you said it was "impressive"... were you deliberately lying or did you really thought it was impressive?
Oh, and just to be honest, I don't think you read the paper.
Quote Posted by Azaran
Papy, science is actually underfunded compared to many other things.
Yes and no. Fundamental science is underfunded, but there are many things in science which are not of a great interest and yet get lots of money.
The main problem I have with this whole thing is that scientific publications do play a very important role in who gets funded or not. Unfortunately, I notice that those scientific publications have more and more a tendency to publish things that are more about looks and buzz than substance. I'm not sure why, but the fact is when I compare my old scientific magazines from the 80s with the one I buy today, there is a significant difference in the ratio of science vs junk. So when I see that what is repeated here is the junk science, it kind of irritate me.
Quote Posted by heywood
Are you nuts?
Actually, I don't think he is. I don't any number, but I'm guessing the amount of money people in the US give to churches is quite high.
