12 ms·
Light completely stopped for a record-breaking minute
- mrt0mat0 13y agothis seems like the coolest thing in the world to see, but yet no pictures? What does stopped light look like?
- gilrain 13y agoTo the naked eye, nothing. If it's stopped, it can't hit your retina!
- mrt0mat0 13y agomy head just exploded trying to grasp this... objects don't move but i can see them, but i can only see them because of light. therefore, if light doesn't move, if the object does, can i see it on the object?
- Zergy 13y agoIf the light doesnt hit you in the retina you don't see it. So no.
- jlebrech 13y agoI think it's for light that entered the object, unsure if any light reflects off the surface. It could be a glass ball which turns to look like a shiny ball.
- Xurinos 13y agoMy guess: The object that does not reflect light to you ceases to exist in your vision. Nothing comes from that direction. Your brain would then attempt to compensate -- as it does for the blind spot in both your eyes -- and fill in the void, perhaps with a fuzzy version of continuity of whatever colors and textures surround the object.
- d23 13y agoWouldn't it just be dark? I think the blind spot is a different phenomenon. This would be no different than being in a pitch black room.
- Xurinos 13y agoMaybe the critical question is: If no light at all comes from the object, is that the same as it being dark, or is it a complete lack of stimulus? If the brain receives noise, it fills in the blanks (http://www.sciencedaily.com/releases/2000/06/000601164617.htm http://www.sciencedaily.com/releases/2000/06/000601164617.ht...). In sensory deprivation, the brain also fills in the blanks (would cite but ended up finding a ton of supporting material in a web search, including an interesting study about the effects of anxiety on amount of hallucinations).
- jerf 13y agoWe don't need to make wild hypotheses about what an object that doesn't reflect light looks like. It's so mundane we have a word for it: "black".
- TallGuyShort 13y agoIt would look black to a light sensor. As he says, your brain does play tricks and fill-in-the-black more than you might think. If you have a blind-spot you don't always perceive the absence of light - you may perceive what your brain is expecting. There are also disorders where it does this too much. I knew a guy who used to do things like overfill his coffee mug all the time, because the mug kept looking empty and then suddenly it was overflowing - his brain just expected the mug to stay empty.
- jerf 13y agoA thing that absorbs light is not a "blind spot". It's black. Are you on the good stuff or something? It's black. Just because someone muttered "quantum" does not make this magic. It's black. What is so complicated about this concept? It literally can not get much more normal than this.
- functional 13y agoWhen you turn off the lights before you go to bed... what happens? Do the things move in the dark, while you can't see them, because there's no light? What if you didn't have eyes? What then? If tree falls in the forest, and no one is there to see it... does it make a sound?
- robocaptain 13y agoThat is the most mind-blowing thing I have read all day.
- egeozcan 13y agoThis is so basic but incredible to think about. How do they know that it is there when it's stopped, provided that it neither has mass nor emits "something"? My brain just stopped.
- amirmc 13y agoProbably by deduction and careful experimental design. If it's not anywhere else, there's only one place left. Also, it is emitted at some point so it's not trapped forever.
- a-priori 13y agoThey know it's there because when they 'unfreeze' it, the light continues on its path and they can detect it then.
- swamp40 13y agoThey sent an image thru the crystal. Three stripes. When they made the crystal transparent again, the same image came out.
- hcarvalhoalves 13y agoIf I understood the experiment correctly, it doesn't look anything exceptional. The crystal would just turn opaque after the first laser is shut off, and when they shot the laser at it to turn it transparent again, the photons from the second laser would be re-emitted in the same trajectory. It's not really "light frozen mid-air", but rather a crystal emitting light after being hit by a laser.
- DanWaterworth 13y agoWhat I want to know is: Does the crystal gain mass with the light stopped inside of it?
- dodo53 13y agowell its energy has increased, so yes, but probably not measurably.
- Zergy 13y agoI though light was massless which was the reason it was able to travel at c and that anything with mass would travel at less than c? If so then how does a massless object add weight to an object by being trapped in it.
- atondwal 13y agoPhotons have zero rest mass, but light has an energy of $h\nu$, where $\nu$ is the frequency, so this gets added on to the mass of our thing. Oversimplified explanation: Photons are massless so they can go as fast as they want without needing kinetic energy, but even massless things can store energy (think of the massless springs you studied in high school physics). Energy is the same thing as mass, but we still refer to photons as massless, in the same way that we think of an (imaginary) massless spring as such; we don't like to think of potential energy as _being the object_, just somehow _there_. This makes more sense if you study physics, in no small part due to the fact that we make it all rigorous (though not to the satisfaction of the mathematicians, I guess...).
- DanWaterworth 13y agoDoes this mean that if you move an object away from Earth's gravitational influence it will increase in mass because it has more potential energy? What about if you heated something up, does it gain mass then? How about sound? Does the sound of my voice cause imperceptible ripples of increased mass as it vibrates everything that it touches? Is a charged battery heavier than an empty one? Is glass heavier with light travelling through it?
- jdmitch 13y agohere is the original paper: http://prl.aps.org/abstract/PRL/v111/i3/e033601 http://prl.aps.org/abstract/PRL/v111/i3/e033601
- ANH 13y agoIt's nice for once to see evolutionary algorithms being used for something completely impractical.* *mostly tongue-in-cheek
- sramsay 13y ago"To break the minute barrier [they] fired a control laser at an opaque crystal, sending its atoms into a quantum superposition of two states. This made it transparent to a narrow range of frequencies. Heinze's team then halted a second beam that entered the crystal by switching off the first laser and hence the transparency." Thus continuing my inability to understand what the fuck anyone is talking about whenever the word "quantum" is used in a sentence. I mean, seriously. This has to be the one area of general reader science journalism in which the journalists -- having about as much as idea as I do about what the physicists are talking about -- just copy down whatever the guys in the lab coats are saying and print it. I work in research computing. When I start talking to someone from our communications department and use a word like "interoperability," they say, "Whoa, slow down. You have to spell that out for our readers." But "quantum superposition?" Oh, what the hell. I understand that is this very, very complicated stuff, and that they can't explain the whole thing from top to bottom every time they mention quantum mechanics. But pithy little paragraphs like this explain absolutely nothing.
- jcbrand 13y agoThere is a Wikipedia article about "Quantum superposition". https://en.wikipedia.org/wiki/Quantum_superposition https://en.wikipedia.org/wiki/Quantum_superposition In quantum states, you cannot know the actual state something is in unless you measure it. Beforehand, you just have different probabilities of where it might be. A quantum superposition of two states means that there are two states the atoms can be in, with specific probabilities assigned to each state.
- sramsay 13y agoRight, and issue three of this article's "multiple issues" is "This article may be too technical for most readers to understand. (April 2011)"
- amirmc 13y agoMy layman's reading of this. We used a crystal that is normally opaque (not see-through) and fired laser beams at it because, well... it seemed like fun! Apparently the laser beam affected the crystal and made it see-through but only for a narrow range of light frequencies (e.g. think of a filter that only allows one colour of light through). Then we thought Hey, we know how to make this here crystal see-through for a particular wavelength of light (think 'colour' if wavelength doesn't work for you). What if we (1) made it see-through with the laser, (2) shone some of that colour light in and then (3) turned off the laser so that it's no longer see-through. I wonder what happens? <time passes> zOMG! We trapped light! In other words, I do think it's possible to get the message across without needing to refer to 'quantum' anything. However, this article is from NewScientist and the intended audience is likely to be vaguely familiar with concepts of superposition via stories of Schrödinger's cat [1] [1] http://en.wikipedia.org/wiki/Schrödinger's_cat http://en.wikipedia.org/wiki/Schrödinger's_cat
- cmiller1 13y agoI work in a photonics lab and for all of the new fancy techniques you see show up in popular science publications for slowing and stopping light... they're all impractical. In the real world when we need to slow down light we still just use delay coils. Wrap tens to hundreds of kilometers of fiber into a coil (using a pump laser amplifier at some point if it gets too long) and just letting the light spin around in circles for the desired amount of time.
- jberryman 13y ago> when we need to slow down light Why do you need to do that? I'd never heard of "photonics" before now.
- cmiller1 13y agoDelaying light is sometimes used for a buffer in optical networks and signal processing, it is also used in the internal workings of certain opto-electronic devices such as optical oscillators; sometimes also used for testing and calibration of optical systems, making sure things are coming out as clean and at the same time as they do through the 'test' delay coil.
- cheapsteak 13y agoCould you give an example of a real world application for stopping/delaying light?
- theorique 13y agoOptical switching? The trouble is that the power levels required for a nonlinear optical material are often much higher than the light beam being switched. So you might need to use a 1000W beam to switch a 1W beam (for example).
- cmiller1 13y agoMost of the switches we use are still opto-mechanical, just mechanically change the connection.
- lettergram 13y agoThis article was pretty poorly written, leading to a couple of questions: 1) It seems to me that the scientists could have simply stored the energy from the light for a period of time? Which would not actually be "stopping" the light. 2) I understand a super position and quantum physics, but I still have vague idea of what happened in the experiment. If I actually understand the terminology and have done various experiments, research, etc. but still don't fully understand, how would the standard reader (without further explanation) understand the article?
- atondwal 13y ago> It seems to me that the scientists could have simply stored the energy from the light for a period of time Strained analogy: It's more like recording a hologram for a minute and then playing it back. It's a one-minute buffer for light, the same way we have video buffers, but for real life.
- weakwire 13y agoThe ultimate solution for information storage?
- deleted 13y ago[deleted]
- datalus 13y agoI look forward to our Middle Earth future. http://en.wikipedia.org/wiki/Silmarils http://en.wikipedia.org/wiki/Silmarils
- Mr_T_ 13y agoBut why? Why not stop time instead?
- balakk 13y agoFor how long?
- pbhjpbhj 13y agoNow.
- lifeformed 13y agoSomeone could already be constantly stopping and resuming time. There'd be no way of knowing.
- vog 13y agoIndeed, maybe the guy with the rocks takes a break right now. (https://xkcd.com/505/ https://xkcd.com/505/)
- swamp40 13y agoI have a dream of a mirror that reflects the light of yesteryears. You would look into it and see the reflections of the people and scene from the exact place and time as you were now - but 10, 20, 50, 100 years ago. It would be a type of city attraction, where people would come to visit daily, so there would always be new and interesting people (and fashions) to see. We actually have the technology to implement this right now, with video cameras, monitors and hard drives. But the simplicity and beauty of a device that actually slows down light to accomplish this - now that would be something.
- fractallyte 13y agoYou're thinking of 'slow glass', from Bob Shaw's short story 'Light of Other Days': http://www.tor.com/blogs/2010/10/slow-glass-seen-from-all-around-bob-shaws-other-days-other-eyes http://www.tor.com/blogs/2010/10/slow-glass-seen-from-all-ar...
- swamp40 13y agoAnalog, 1966 - Well, I guess he didn't get the idea from me, then. Melancholy synopsis from Wiki: While on vacation, they visit a slow glass merchant and notice the man's wife and child through the window, playing inside the house. When they enter, however, the house is deserted; only then do they realize that the window is made of slow glass, giving the lonely man his final glimpses of his long-dead wife and child. It's funny how stories from your youth can permeate into your memories.
- fudged71 13y ago>We actually have the technology to implement this right now, with video cameras, monitors and hard drives. Jeez, this sounds really fun to build and exhibit...
- redeemedfadi 13y agoRadiolab had a segment about stopping light back in February. It's a great listen: http://www.radiolab.org/2013/feb/05/master-universe/ http://www.radiolab.org/2013/feb/05/master-universe/
- kibwen 13y ago"Tens of seconds of light storage are needed for a device called a quantum repeater, which would stop and then re-emit photons used in secure communications, to preserve their quantum state over long distances." That's quite a lot of latency. Assuming many repeaters, does that mean a quantum-encrypted ping from one side of the world to the other might be measured in hours?
- stan_rogers 13y agoNot necessarily. It's not so much that a 10-second delay will be introduced at every repeater, but that a practical system/implementation requires that a delay of up to ten seconds may be introduced when required by traffic, etc. A straight-pipe, latency-free, synchronous-only system would require a lot more infrastructure to support (analogous to the earliest direct-connection telephone systems).
- xenophanes 13y agoWait so is the story basically along the lines of, "Light hits black paint. Absorbed, stops. Comes out later." ?
- xenophanes 13y agoI asked a physicist. The headline and article are both stupid but the science is good. It's like the paint thing except that when light hits paint, the paint affects the light, they interact, the information in the light gets messed up. With the fancy crystal thing they are preserving the information.
- qq66 13y agoThis is interesting... every time I've read a "light slowed down" article over the last 10 years it's been Professor Lene Hau. This time it isn't.
- teeja 13y agoI strongly dislike headlines like this (which all the crappy science news digests, like New Scientist, frequently indulge in). If light could actually be "stopped", it wouldn't be light any more. It also can't be "slowed down"; it always travels at exactly the speed of light in whatever medium it's in. OTOH, if the light's energy is absorbed by electrons, it's not "light" any more. All matter does this trick all day every day - it's not news. This sort of sentence only sows confusion in a lot of minds.