(Phys.org)—Light behaves both as a particle and as a wave. Since the days of Einstein, scientists have been trying to directly observe both of these aspects of light at the same time. Now, scientists at EPFL have succeeded in capturing the first-ever snapshot of this dual behavior.
Quantum mechanics tells us that light can behave simultaneously as a particle or a wave. However, there has never been an experiment able to capture both natures of light at the same time; the closest we have come is seeing either wave or particle, but always at different times. Taking a radically different experimental approach, EPFL scientists have now been able to take the first ever snapshot of light behaving both as a wave and as a particle. The breakthrough work is published in Nature Communications.
When UV light hits a metal surface, it causes an emission of electrons. Albert Einstein explained this "photoelectric" effect by proposing that light – thought to only be a wave – is also a stream of particles. Even though a variety of experiments have successfully observed both the particle- and wave-like behaviors of light, they have never been able to observe both at the same time.
A research team led by Fabrizio Carbone at EPFL has now carried out an experiment with a clever twist: using electrons to image light. The researchers have captured, for the first time ever, a single snapshot of light behaving simultaneously as both a wave and a stream of particles.
The experiment is set up like this: A pulse of laser light is fired at a tiny metallic nanowire. The laser adds energy to the charged particles in the nanowire, causing them to vibrate. Light travels along this tiny wire in two possible directions, like cars on a highway. When waves traveling in opposite directions meet each other they form a new wave that looks like it is standing in place. Here, this standing wave becomes the source of light for the experiment, radiating around the nanowire.
This is where the experiment's trick comes in: The scientists shot a stream of electrons close to the nanowire, using them to image the standing wave of light. As the electrons interacted with the confined light on the nanowire, they either sped up or slowed down. Using the ultrafast microscope to image the position where this change in speed occurred, Carbone's team could now visualize the standing wave, which acts as a fingerprint of the wave-nature of light.
While this phenomenon shows the wave-like nature of light, it simultaneously demonstrated its particle aspect as well. As the electrons pass close to the standing wave of light, they "hit" the light's particles, the photons. As mentioned above, this affects their speed, making them move faster or slower. This change in speed appears as an exchange of energy "packets" (quanta) between electrons and photons. The very occurrence of these energy packets shows that the light on the nanowire behaves as a particle.
"This experiment demonstrates that, for the first time ever, we can film quantum mechanics – and its paradoxical nature – directly," says Fabrizio Carbone. In addition, the importance of this pioneering work can extend beyond fundamental science and to future technologies. As Carbone explains: "Being able to image and control quantum phenomena at the nanometer scale like this opens up a new route towards quantum computing."
Explore further:
Optical 'watermills' control spinning light
More information:
"Simultaneous observation of the quantization and the interference pattern of a plasmonic near-field." Nature Communications 02 March 2015. DOI: 10.1038/ncomms7407

kow
5 / 5 (2) Mar 02, 2015codectified
5 / 5 (2) Mar 02, 2015douglaskostyk
3.7 / 5 (3) Mar 02, 2015This seems to be an image created by many electrons, which have experienced an interaction where there is a high probability of finding a photon along the nanowire. determined by the many photons' wave characteristics.
DarkLordKelvin
3.8 / 5 (10) Mar 02, 2015Double Slit the Quantum Phantom
5 / 5 (1) Mar 02, 2015the-truth-seeker
5 / 5 (2) Mar 02, 2015vladimirphizik
1.8 / 5 (5) Mar 02, 2015gravitus.ucoz.ru
buzzsaw107
2 / 5 (8) Mar 02, 2015vic1248
4 / 5 (4) Mar 02, 2015billpress11
1.8 / 5 (4) Mar 02, 2015http://www.scribd...-Physics
payge887
1 / 5 (2) Mar 02, 2015jediknight190501
1 / 5 (3) Mar 02, 2015kamcoautomotive
Mar 02, 2015hemipwr54
1 / 5 (3) Mar 02, 2015indio007
3 / 5 (4) Mar 02, 2015DarkLordKelvin
2.7 / 5 (7) Mar 02, 2015Are you sure? What if the standing waves are "made out of" electrons (like for example the surface plasmon polaritons actually probed in this study)?
DeliriousNeuron
3.7 / 5 (3) Mar 02, 2015DeliriousNeuron
5 / 5 (3) Mar 02, 2015Dethe
1 / 5 (12) Mar 02, 2015The same effect we would recognize, if we would live at the water surface like the waterstriders and if we would observe it with its own ripples. The more undulating places of surface are also more deformed, so that they represent a more dense obstacle for another waves. It's geometric effect, which has its origin in tiny density fluctuations of vacuum, i.e. the Higgs field. The more the space-time undulates, the more these tiny fluctuations are getting exposed, the more the vacuum look more dense at the same places. These density fluctuations are also indicia of additional dimensions of space-time in similar way, like the Brownian noise at the water surface is the evidence of additional dimension of the underwater.
Dethe
1 / 5 (11) Mar 02, 2015The electromagnetic wave behaves in the same way, as it has two vector components, which are mutually dependent: if we induce the change of electrostatic field intensity, we also induce the change of magnetic field intensity in perpendicular direction. And whole the piece of that foam also becomes more dense like the soap foam shaken - so it does behave like the obstacle or sparse "particle" at the same moment for all waves passing the same place at the same moment. This effect is apparently cumulative - the higher is the energy density, the higher is the mass density.
Dethe
1 / 5 (11) Mar 02, 2015Dethe
1 / 5 (11) Mar 02, 2015rufusgwarren
3.7 / 5 (3) Mar 02, 2015rufusgwarren
2.3 / 5 (3) Mar 02, 2015vic1248
1 / 5 (2) Mar 02, 2015The "wave-to-wave" event is represented in when two laser light waves running in opposite directions in the nanowire meet and form standing waves. The "particle-to-particle" event is represented in when electrons passing by the standing waves interact with photons (electron-to-photon is the particle-to-particle event in this case) and exchange energy packets (quanta.)
Please see my earlier comment too.
skip_gross
5 / 5 (2) Mar 02, 2015automaticsteam
3 / 5 (2) Mar 02, 2015baudrunner
1 / 5 (3) Mar 02, 2015The scientists got it right this time. Most don't get how light works.
kriminy
3.7 / 5 (3) Mar 02, 2015Jeremy Bransford
3.7 / 5 (3) Mar 02, 2015So, I like to remind myself of what light is by calling it electromagnetic radiation. In this way I recall that light has an electric component (particle) and a magnetic component (wave), on perpendicular planes, with a velocity that is perpendicular to the intersecting planes. Magnetic fields and electric particles interact during flight and may influence one another. We know the behavior of electricity and magnetic fields and photons have similar characteristics to electrons. In regards to the image, it seems like what we observe with a valence shell on an atom - a probability field, and since light particles move so fast, it has a similar effect
RantOnAtMath
3 / 5 (2) Mar 02, 2015The particles appear along the direction of the lower right side, with represents, I believe, the time direction. Notice that the wave amplitude grows or shrinks with time. (I can't tell which direction of time is the forward one). If photons weren't quantized, this growth/damping would be continuous as the wave exchanges energy with the electrons. But photons ARE quantized, and so energy exchanges in discrete bumps.
emaalouf
5 / 5 (1) Mar 02, 2015This looks like the reflections/by-products of the electrons interacting with the photons at close range, it does not show nor explain how the photons or the electrons can exhibit particle wave states?!
RantOnAtMath
5 / 5 (1) Mar 02, 2015But even in the "wave-like" direction perpendicular to that there appear to be slight oscillations. I'm wondering whether that's also some quantum effect, or an experimental artifact.
bbbbwindows
2.1 / 5 (7) Mar 02, 2015It is beginning to look like the entire universe from the smallest particles to the largest galaxies are shaped by the forces of electromagnetism. This could easily result in a true "grand unified theory of everything". It's pretty obvious that gravitational forces have failed in this regard, unless one considers a mathematical model as a sufficient goal.
liquidspacetime
1.6 / 5 (7) Mar 03, 2015Dark matter has mass. Dark matter physically occupies three dimensional space. Dark matter is physically displaced by the particles of matter which exist in it and move through it.
The Milky Way's halo is not a clump of dark matter anchored to the Milky Way. The Milky Way is moving through and displacing the dark matter.
The Milky Way's halo is the state of displacement of the dark matter.
The Milky Way's halo is the deformation of spacetime.
What is referred to geometrically as the deformation of spacetime physically exists in nature as the state of displacement of the dark matter.
A moving particle has an associated dark matter displacement wave. In a double slit experiment the particle travels through a single slit and the associated wave in the dark matter passes through both.
Joe_Chang
Mar 03, 2015SteveP
not rated yet Mar 03, 2015qquax
5 / 5 (4) Mar 03, 2015You are not looking at light 'particles' in this photos. It's just standing waves the same phenomenon that you can produce with water in your bathtube.
The only thing 'particle' is the quantum interaction of the light field with the electrons.
This is a clever experiment completely spoiled by the unnecessarily sensationalist reporting that make the authors look like rubes.
Arnon Burns
1.7 / 5 (3) Mar 03, 2015markradcliff
3 / 5 (1) Mar 03, 2015antialias_physorg
4.8 / 5 (4) Mar 03, 2015The standing wave (responsible for the acceleration/decelration of the electrons in the test beam) is the wave part of the observation. The direction change of individual electrons in the test beam is the particle part (because its quantized by individual photon-electron interaction).
vlaaing peerd
5 / 5 (2) Mar 03, 2015Give credit due were it's due, Christiaan Huygens had setups in the 1680's showing light behaves like waves that disagreed with Newton's particle theory of light. While Newton was able to show light had particle-like behaviour the general concensus stayed that Newton was right. Only til Fresnel in the 19th century tested Huygens wave theory of light, it was shown to be fundementally correct and the huygens-fresnel principle was born.
Interesting fact is that Huygens already had a completely correct lightwave theory in 3 dimensions, be it he falsely thought it needed aether to make the waves propagate, like sound waves needed a medium.
So scientists have been trying to witness both light and wave properties since the late 1600's.
Joe_Chang
not rated yet Mar 03, 2015If it is moving, it moves along straight line. If it hits something, it may pass through/halfway, reflect or deflect. It will lose momentum/speed anyways.
Does any light or EM wave ever slowdown? when light passing water into air, it speeds up.
If light is particle, how a particle hits mirror and reflect back? What bounces it back? The electron? The nucleus? The empty space within silver atoms?
Joe_Chang
not rated yet Mar 03, 2015Totally agree! You know much better.
antialias_physorg
4.6 / 5 (9) Mar 03, 2015Light is not a particle. It exhibits particle-LIKE properties under certain conditions.
Light is not a wave. It exhibits wave-LIKE properties under certain conditions.
There is a reason why it's called a particle-wave.
Joe_Chang
1 / 5 (5) Mar 03, 2015Light is gravitational wave produced by exited atoms.
Photonists soon will be selling sneakoil for a living.
Joe_Chang
1 / 5 (1) Mar 03, 2015What bounces it back? The electron? The nucleus? The empty space within silver atoms?Whats the mechanism?
Mimath224
1.5 / 5 (2) Mar 03, 2015swordsman
4.3 / 5 (3) Mar 03, 2015A particle????
tadchem
5 / 5 (1) Mar 03, 2015The Maxwell Equations for electromagnetism show that a photon is extensive and dynamic in four dimensions. Photographs are two-dimensional.
Joe_Chang
1 / 5 (2) Mar 03, 2015if the sun has a big ejection/quake, we should be able to detect it 500 seconds later. we might even have a earthquake.
atoms, each has mass, when atoms exited, their fields exited, within that field, you feel light.
our eyes detect gravity wave all the time. the source/atom has to vibrate at high f to produce visible light. only atoms able to vibrate at high f. a little ball weights 1g will take a lot energy to vibrate at such high speed.
if you put a bell in vacuum, put gravity wave detector in the center, knock the bell and you should detect gravity wave.
the wave is electrostatic force in nature, so we call it em wave.
Noumenon
2.3 / 5 (3) Mar 03, 2015Yes that's the correct way of viewing it, ... that is what is going on imo. The observational conditions are what determine the conceptual form the underlying reality is forced to take on. Whatever the underlying reality "is" apart from observation, it has no conceptual form. QM entities simply have no conceptual value (specific spin, position, etc) just prior to measurement ,... this implies that the particular apparatus defines the conceptual form and so possible values,...i.e. the Hilbert-space basis.
Joe_Chang
1 / 5 (3) Mar 03, 2015light is not wave nor particle, light is gravitational pause produced by exited atoms.
Science has never been absolute, what makes you think today's science is all correct? In fact, science is so fucked up. Present theories of atomic structure, gravity and light are all wrong. Discuss at fuckedscience.com
Noumenon
3 / 5 (6) Mar 03, 2015People searching for crank theories will have no trouble finding yours.
dana_wanapskana
5 / 5 (1) Mar 03, 2015Joe_Chang
2 / 5 (4) Mar 03, 2015if you have the means to debunk, let's see it.
DarkLordKelvin
3.7 / 5 (6) Mar 03, 2015DarkLordKelvin
3.7 / 5 (6) Mar 03, 2015Actually, yes, if the title (of the phys.org article) were correct, it would do both of those things. However, as several posters have (correctly) noted, the title is a gross misinterpretation of the physics that are actually responsible for the image.
Dethe
1.5 / 5 (8) Mar 03, 2015russell_russell
1 / 5 (1) Mar 03, 2015Physical assertions is what QM asserts.
What does "forcing reality" mean?
Of course QM negates determinism.
You go one better - asserting "new physics" negates probability as well.
What is "forcing reality"?
The article is a "gross misinterpretation of the physics".
Reality is not mentioned.
Joe_Chang
not rated yet Mar 03, 2015thenakedscientists.com/forum/index.php?topic=26362.275
Frosted Flake
3.7 / 5 (3) Mar 04, 2015Laser strikes nanowire, causes photoelectric effect, sets up standing wave of electrons. Electron beam passes, is disturbed by edge diffraction, captures texture of standing wave, is subsequently noted and 'photographed' by supermicroscope that 'sees' electrons. JPEG is not a CCD image of light, thus photo. Is a computer representation of electron beam displaying edge diffraction pattern. Electrons are not waves except in string theory, and this ain't that.
Naturally, I hope to SHOWN that I am wrong., If I am wrong. But let's quit beating around the bush. The real questions are :
1/ Particle of what, just exactly?
2/ Wave in what, just exactly?
3/ Does anyone on the team have any idea what I refer to when I ask about Primer Fields?
Joe_Chang
2 / 5 (4) Mar 04, 2015if more readers are clear like you, those scientists will not able to cheat again. in our history, no one lied more than science. y2k, global cooling, god particle, graviton,,,
Mimath224
5 / 5 (1) Mar 04, 2015Thanks DLK, I knew I'd wrote it wrongly, I couldn't think of that ' interference pattern' phrase...one of the most basic features of physics and I forgot it, Ha! Man, I'm getting old! You said for me...what I meant was that the 'interference pattern' is produced by a moving event. Thanks again
@Frosted Flake If you are referring to to the magnetic fields around 'paticles' and 'matter' then I assume you have a problem with accepting duality. This principle is all around us so I don't see why it can't be at QM level also.
casualjoe
1 / 5 (2) Mar 04, 20151/ Energy
2/ Space
3/ Yes, they are absolute shite.
Landrew
4 / 5 (2) Mar 04, 2015Joe_Chang
1 / 5 (1) Mar 04, 2015bs
Joe_Chang
1 / 5 (1) Mar 04, 2015light is not particle nor wave.
light/em wave is gravitational pause/wave produces by exited atoms.
antialias_physorg
3.8 / 5 (4) Mar 04, 2015DarkLordKelvin
3 / 5 (6) Mar 04, 2015antialias_physorg
3.8 / 5 (4) Mar 04, 2015The electrons aren't the thing that's being tested here for wave/particle duality. They are the measuring apparatus.
The electron stream close to the wire gets affected by the wave aspect of the laser beam (the photons) that set up the standing plasmon wave as evinced by the speedup/slowdown of the electron in the stream. And they get affected by the particle aspect (by the interchange of discrete quanta) that change their direction in deiscrete steps.
(As a side note: electrons also exhibit particle/wave duality. The wave-like behavior can be easily demonstrated by single electron interference and tunnel effect and also the fact that electrons don't fall into atomic nuclei)
Osiris1
1.7 / 5 (3) Mar 04, 2015jim_zhao_cc
3 / 5 (2) Mar 05, 2015Noumenon
2.3 / 5 (3) Mar 05, 2015You stated "...light is gravitational pause produced by exited atoms."
For starters the electromagnetic force is ~10^39 times stronger than the gravitational force,... in fact I used "~" because mass is independent of charge wrt the ratio of these two forces so the ratio depends of the mass of the specific charge, ....further exposing your statement as gibberish.
Joe_Chang
1 / 5 (1) Mar 05, 2015why is electron not stick to the proton under 10^39g attraction force? standard model of atomic structure is gibberish.
get in the TNC forum debunk if you got it.
Joe_Chang
1 / 5 (1) Mar 05, 2015An atoms force field does not end at atom radius, but extend to infinity. In whole, an atom or planet maybe electrically neutral, but Every charge within has its own force field beyond distance, those forces overlapped to produce chemical bonding, magnetism and gravity. Ever wonder why is Fe=q1q2/r^2, Fg=m1m2/r^2, and mass proportional to proton numbers within it?
Noumenon
3.4 / 5 (5) Mar 05, 2015Because of uncertainty principle for closest electrons and exclusion principle for others. Since the SM is accurate, your complaint is with Reality,... indeed it can seem like gibberish.
Joe_Chang
1 / 5 (1) Mar 05, 2015Noumenon
3.4 / 5 (5) Mar 05, 2015"discharge" means flow of electrons. I answered this with uncertainty principle.
Joe_Chang
1 / 5 (1) Mar 05, 2015Joe_Chang
1 / 5 (1) Mar 05, 2015a bunch bs?
Noumenon
3.4 / 5 (5) Mar 05, 2015The potential energy term (from the nucleus if considering the electron) of the Schrodinger equation determines the stationary states within "an atom".
It is just a consequence of the isotropy of the respective forces, wrt the equation form. The respective magnitudes are no where close at post BB energies.
PS: I will have to counter your invalid 1-rating. Cranks and trolls should not use the rating system.
Joe_Chang
not rated yet Mar 05, 2015quite a certain answer. principle insulator? is your science making you calling name?
Joe_Chang
1 / 5 (1) Mar 05, 2015Joe_Chang
1 / 5 (1) Mar 05, 2015DarkLordKelvin
3.5 / 5 (8) Mar 05, 2015Have you studied quantum mechanics? This is a basic question that is covered in most first year courses. The answer takes a bit of time to set up properly, so it's best if you look it up elsewhere and ask for clarification here if you don't understand something specific. Good answers can be found lots of different places .. a couple examples are here:
http://physics.st...ith-them
http://www.fnal.g...bob.html
cemery50
5 / 5 (2) Mar 05, 2015Joe_Chang
1 / 5 (1) Mar 05, 2015wm, graviton, photon, god particle are all bs. what makes you think they are not?
Joe_Chang
Mar 05, 2015Joe_Chang
not rated yet Mar 06, 2015antialias_physorg
3.4 / 5 (5) Mar 06, 2015Because by confining the electron to a smaller space (the nucleus) you are decreasing the location uncertainty. According to the Heisenberg Uncertainty Principle if you decrease the location uncertainty you are increasing the momentum uncertainty (and hence the average momentum). Increasing the average momentum means you are increasing the energy of the electron.
This means that such a state would be a higher energy state for the electron than staying in its orbital. (quite apart from the quantum nature of energy exchange so that you have to have integer multiples of h)
Read: It takes a lot of energy to push an electron into a nucleus...something that can happen in something that can supply that energy (e.g. when gravity pushes the electrons of a collapsing star above a certain mass into their nuclei to from a neutron star)
Joe_Chang
1 / 5 (3) Mar 06, 2015what force keeps them apart? how wuantum nature of energy exchange? what's the mechanism?
Noumenon
3.4 / 5 (5) Mar 06, 2015You have been told by myself, DarkLord, and AntiAlias, but you continue to ask?
Are you expecting a mechanical epicycle explanation?
Joe_Chang
1 / 5 (5) Mar 06, 2015the reason not a legit answer in this discussing proofs you 3 don't have any.
DarkLordKelvin
3.5 / 5 (8) Mar 06, 2015What force keeps the Earth from crashing into the Sun? There isn't one .. there also isn't a "force" that keeps an electron from crashing into the nucleus of an atom. The *mechanism* that keeps the orbits (although 'orbit' is not really correct for the electron, it will do for this analogy because the answer is the same) stable in both cases is the simultaneous conservation of energy and angular momentum.
antialias_physorg
4.3 / 5 (7) Mar 06, 2015Nope.
Notice that the nucleus has a lot of protons in a very small space? If charge were the strongest force that nucleus would fly apart instantly. However the strong nuclear force is stronger and keeps them confined. (The reason why the strong nuclear force doesn't dominate everywhere is because it doesn't have much of a range)
The reason is you're just not listening. (or, and I'm coming to suspect this very strongly, don't have the brains to understand what you're reading)
Joe_Chang
1 / 5 (6) Mar 07, 2015a bow of whonton soup, made by few top scientists.
Mimath224
3 / 5 (2) Mar 07, 20151. '...this discussing proofs...' what kind of 'proof' do you want? One can't just go to lab, look though some microscope and see what's going on at the QM level. It's only in very recent years that technology has provided us with a view of atoms. What you need to do is go and study a bit of history to see how difficult a climb it has been to get to this current stage. Appreciate what Thomson, Rurherford, Bohr (just to name 3) did and THEN ask yourself about 'proof'.
2. I remember going to my elementary physical chem class where atoms were expressed with e- given in basic circular orbits (valence purposes). Wow, I thought, this is great. The more advanced course, a different tutor said (one Dr. Gould) 'remember early chem orbits...well, forget all that...' and out came s,p,d &f orbitals...oh my giddy aunt. (cont.)
Mimath224
3 / 5 (2) Mar 07, 20153. Don't forget the e- orbitals are worked with probability so it is possible that e- does approach the nucleus. Look at the 'lobe' representation of the d & f orbitals and you'll notice the diagrams are almost a figure '8' which MIGHT suggest that e- goes into or closely around the nucleus.
I'm just an interested layman but I do try to learn by either reading or asking. I don't find it easy but it's worth that extra effort.
DarkLordKelvin
3.4 / 5 (5) Mar 08, 2015That the electrons actually have a finite probability density *inside* the nucleus! This is particularly important for larger atoms with unstable nuclei, because they can undergo what is called "electron capture decay", where a proton and electron combine inside the nucleus to form a neutron. That "combining" process is energetically "uphill", so it is only possible for isotopes that can then lose energy to relax to a form that is more stable than the initial isotope. An example is Rb-83, which decays by e- capture to form Kr-83. Anyway, the point is that these mechanisms are enabled because the electron orbitals overlap with the nucleus.
Joe_Chang
Mar 08, 2015Dethe
1 / 5 (2) Mar 08, 2015Mike_Massen
1 / 5 (2) Mar 08, 2015https://share.san...4vY7A1sY
The issue we face re any fusion process is more bang out for less buck in...
Dethe
1 / 5 (2) Mar 08, 2015Joe_Chang
Mar 08, 2015EnsignFlandry
not rated yet Mar 09, 2015On the other hand, our linguistic limitations make us adopt this binary situation. A more logical view is that light is neither a particle or a wave, but something new. Some have called this a "wavicle". Is this picture a wavicle?
Joe_Chang
Mar 09, 2015Accounts
not rated yet Mar 09, 2015but it sur is a darned purtty picture.
baudrunner
not rated yet Mar 10, 2015Photonic waves happen when a source of excitation produces them. Energy is transferred from this source through light-permeable mediums which are comprised of the absorbing and emitting atoms which through this continuous and combined action - provided the source of the excitations is continued - produce detectable waves, just like water molecules produce water waves. A single photon cannot be used to study wave/particle duality. The word 'photon' is used to describe the amount, or quanta, of energy which is transmitted/absorbed in this process during a single interaction between two components of the medium. The amount of this energy is a function of the intensity of the source of excitation. Enough energy, such as electron beams striking a tungsten target, will strip the electrons from their nuclei, and this process is the same, but at the nuclear level, and we get Xrays.
oginimeg
not rated yet Mar 12, 2015The next step is to assemble an apparatus that images entangled polarized photons as they change polarity. It would seem relatively simple, beginning with "A pulse of (entangled) polarized laser light is (split and) fired at (two) tiny metallic nanowire(s)," then using the ultrafast microscope to image the position where change in speed occurred, the polarity of one photon stream is changed, and the polarity change of the entangled photons is imaged through a polarized lens.
If the images could be rendered rapidly as on-off bits, the apparatus could be the basis for hack-proof encryption.