Slashdot Mirror
Photo First: Light Captured As Both Particle and Wave
mpicpp sends word that scientists have succeeded in capturing the first-ever snapshot of the dual behavior of light. "It's one of those enduring Zen koans of science that we've all grown up with: Light behaves as both a particle and a wave—at the same time. Einstein taught us that, so we're all generally on board, but to actually understand what it means would require several Ph.D.s and a thorough understanding of quantum physics. What's more, scientists have never been able to devise an experiment that documents light behaving as both a wave and a particle simultaneously. Until now. That's the contention of a team of Swiss and American researchers, who say they've succeeded in capturing the first-ever snapshot of light's dual behavior. Using an advanced electron microscope – one of only two on the planet – at the EPFL labs in Switzerland, the team has generated a kind of quantum photograph of light behaving as both a particle and a wave. The experiment involves firing laser light at a microscopic metallic nanowire, causing light to travel — as a wave — back and forth along the wire. When waves traveling in opposite directions meet, they form a "standing wave" that emits light itself — as particles. By shooting a stream of electrons close to the nanowire, the researchers were able to capture an image that simultaneously demonstrates both the wave-nature and particle-nature of light. 'This experiment demonstrates that, for the first time ever, we can film quantum mechanics — and its paradoxical nature — directly,' says lead researcher Fabrizio Carbone of EPFL, on the lab's project page. The study is to be officially published this week in the journal Nature Communications."
every dual slit experiment shows light behaving as both particle and wave, because every photon only interferes with itself. Two or more photons never interfere with each other.
If you attempt to measure it in the way you would measure a wave, it will present itself as a wave.
If you attempt to measure it in the way you would measure a particle, it will present itself as a particle.
Light doesn't choose to be a particle or a wave at any given time, the measurement we use defines the characteristics it has. Nothing more, nothing less.
The wave or the particle? .. i'm for the wave
Would someone kindly dumb down the summary a touch?
If video games influenced behavior the Pac Man generation would be eating pills and running away from their problems.
> Light Captured As Both Particle and Wave
Well, thanks. I'm glad the universe didn't telefrag.
(-1: Post disagrees with my already-settled worldview) is not a valid mod option.
From the fine article it provides a caption to the graphic
"The bottom "slice" of the image shows the particles, while the top image shows light as a wave""
Looking at the graphic the top image is a 3-D display and the bottom just a color coded 2-D representation with topo lines. I see nothing in this displaying the wave aspect and particle aspect. Mistake?
That wave-like motion is not light, but the group motion of electrons on the nanowire.
Oops...
I have seen these images so many times before. Standing waves, traveling waves, plane polarized wave entering a ferrite core and its plane of polarization turning and twisting, all in glorious 24 bit color. But all those images and animations came from Ansoft High Frequency Structure Simulator software. Not actual experimental physically observed phenomena. And not at light frequencies. Microwave wavelengths mostly. So seen it so many times before, but definitely not meh.
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
> but to actually understand what it means would require several Ph.D.s and a thorough understanding of quantum physics
No, just some understanding of statistics and calculus up to tensors along with an ability to know why you know something rather than just knowing things.
When we make out relatively simple things (like quantum physics) to be complex, when in fact they are just strange we do a disservice to those who might otherwise put in the effort to understand.
I should use this sig to advertise my book ISBN-13 : 978-1501515132.
Light behaves as both a particle and a wave—at the same time. Einstein taught us that, so we're all generally on board, but to actually understand what it means would require several Ph.D.s and a thorough understanding of quantum physics
Stop pretending physics is spooooky. It's not that difficult to understand, at least at a superficial level. And I don't have a degree, let a lone a Ph.D, but even I can explain it (again, superficially):
Time dilation means that the faster you go, the slower time goes. If you're travelling at the speed of light in a vacuum, then the speed at which you're travelling through time is slowed infinitely. This means a photon experiences no passing of time between the moment it is created, and the moment it collides with something.
But the speed of light is finite, so it has to travel through time to go between two points. But because from the photon's perspective it's travel is instantaneous, it can't experience that time. So a photon doesn't know where it's going to land, until it does. And so until it does land, it could have landed anywhere. So when a photon is created, it travels out in all directions, like a wave, until it lands somewhere and the wave collapses.
The part that's hard to understand is the why.
To my mind the fact that matter also behaves like a wave is even more mysterious. Louis de Broglie proposed in1924 that matter has a wavelength of about h / p where p is momentum. Now h is very small so for everything but the tiniest items the wavelength is extremely small and unobservable.
Good times.
I had no idea photons were so colorful.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
It has been several hours since the latest threats and developments of the war with ISIS. Slashdot please report
NO! That is just the opposite of what the News for Nerds should be reporting. More Science, More Engeering More Hacks More D&D, More SciFi less war coverage unless its BSD vs GNU, or Emacs vs Vi vs Ed, and for love of $Deity less politics outside debate over SystemD vs LaunchD vs OpenRC vs SysV Init.
---Saying gnome 3 is better than windows 8 not so much a compliment as it is damning with light praise.
https://www.youtube.com/watch?...
What another groan worthy /. summary. It's not the standing waves that equate to photons. The only thing photonic here is the quantum exchange between the light field and the electrons used for imaging.
And no, you don't need to have several PhDs to understand this, reading the articles at the links totally suffices.
every dual slit experiment shows light behaving as both particle and wave, because every photon only interferes with itself. Two or more photons never interfere with each other.
If you want to see two photons interfering in a double slit experiment you don't have to do anything more complex that direct a laser pointer at a narrow slit. This is generally what happens in almost all double slit experiments ever performed by school kids and undergrads to demonstrate diffraction. You are talking about a special version of it to show that photons self-interfere but this does not exclude them interfering with other photons if there are some present.
I wish physicists would stop using the word "measurement" when talking about quantum mechanics....We don't get to keep the original particle after we're done.
Actually that is not true if you go to high enough energy: have a look at this. Those four tracks coming out of the centre of the ATLAS detector at the LHC are muons, a heavy cousin of the electron. The muons are neither stopped nor destroyed by the detector but they do lose a little of their energy as they pass through it but for high energy particles this really is a very small, non-instrusive fraction of their energy. We can even use the curvature of the track in ATLAS' magnetic fields to measure the momentum of the particle.
Even if you stay at low energies there are biophysicists who can use lasers to pull apart single DNA and other organic molecules in non-destructive ways to study how they fold which involves quantum transitions between different folding states. So there are plenty of non-destructive QM based measurements which we can do both on fundamental, and non-fundamental particles.
If your objection is that we have 'changed' the system by making the measurement then perhaps it is worth reflecting that, at a fundamental level, everything is quantum mechanical. Hence there is no measurement that you can make which will not involve changing the system you are measuring. So if your criterion is that your measurement must not change the system you have just ruled out any measurement which any scientist has ever made.
They reinvented a Nixie tube that works with photons, not electrons. Nixie's cause electrons to emit light a short distance away from the metal wires, at the point where the electrons sense that they are going to go splat into the anode, a moment before they actually do.
It is not theoretically possible to both capture a single photon as both a wave and particle simeltaneously. What they have done is show a set of thousands (millions?) of electron photon interactions at the same instant in time arranged on 2 axis. Basically the lower and slower lumps become particles and the upper smoother lines show waves. So its neat and a first for light waves afaik but misleading as it is not a photo of a single photon.
The latest from the War on ISIS: Federal funding to the tune of eleventeen brazillion American Euros has been allocated to several projects to develop indestructible virgin fembots for a special assault anti-ISIS force.
Don't know if what you say is true, but if it is, then the phrase 'wave-particle duality' is misleading gibberish.
I have always suspected this is the case, but do not have the time or interest to grok the mathematics.
However, it has always seemed to me that 'wave-particle duality' obscures far more than it elucidates.
Saying "the slower time goes" is meaningless. It's like saying 'the meter grows shorter".
If it's shorter, it's no longer a meter in length. It's like saying green is now [more] red. or gold and white is now black and blue. You're just redefining words and creating no insight or understanding.
If time "slows down', whatever the fuck that means, it is no longer communicating in the same frame of reference, and so there is no connection to base a rational understanding on.
This is the whole problem. If you keep redefining terms and concepts, and doing so in ways that has no common-sense or real-world graspable meaning, then of course physics becomes inconceivable and spooky.
The "debate" over the shape of the earth or the cause of 11/9, or the species of the House of Windsor are up for "debate" still. Doesn't mean the debate is anything but nuts.
Aether is becoming God for those still believing it:
Aether/God does this!
(proof it doesn't)
Uh, No, because Aether/God isn't like that, it's like this!
(proof it doesn't)
.
.
.
never ending shifting of claims indicating that the damn thing doesn't exist because otherwise it wouldn't have to change to something else when looked for.
If I attempt to look a rock, it will present itself as a gray object.
If I attempt to hit the rock with a stick, it will present itself as hard.
Thus I conclude the rock has dual nature: it is both a gray object and it breaks a stick. Next I will try to fling poo at it and document the results.
Maybe the rock 3 different characteristics simultaneously. But to prove that, I must manage to look at it, hit it with a stick and poo on it, all at the same time. Science is hard.
..is that the human condition and our language that goes with it isn't really in touch with the nature f the universe.That we create 2 different names for what is essentially the same thing. It's one or the other in my opinion. We may perceive it as 2 different things but ultimately it's one.When a tennis ball hits the ground, it stretches out. It's still a ball nothing changes there. The 2nd state as they see it isn't really a state - it's a condition. Light waveicles if you like, are just that.
"Communications" are not peer reviewed papers, they are letters, and Nature is a populist rag. Wake me up when they publish in a real physics journal.
My problem with supporting most scientists is that they have no greater sense of responsibility than the general masses, yet produce effects that carry great destructive potentials. Weapons get released before the know how on how to defend against it is even considered. Bad move!
It's even worse than the fool who ordered and the greater fools who followed, the order to dock the war ships in Pearl Harbor during times of war. When at war the fleet is NEVER docket for any reason other than repairs that cannot be done at sea. Yet here practically the whole fleet was sitting there. Nothing short of treason.
I daresay, according to close whitnesses, the scientists behind the A-bomb got a wakeup call when they realized what they had done. So while you are developing the latest and greatest whatever, have you considered how to defend against your creation should it be needed? Or, are you only considering short term success for yourself?
One missed detail in the thinking of "mutually insured destruction" is that there are people who are bent on going down and taking others with them. They too can move up the ranks of most places with enough purpose. A man of low intelligence can reach further with good purpose than smart men with poor purpose. Most people think that they don't want to die and nobody else would want that. Yet here they are clearly, if nothing but action, drive towards death and destruction.
A man is as valuable as he helps others. Not as how much damage he can cause.