Episode 50: Particles And Waves - The Mechanical Universe

Episode 50. Particles and Waves: Evidence that light can sometimes act like a particle leads to quantum mechanics, the new physics.
“The Mechanical Universe,” is a critically-acclaimed series of 52 thirty-minute videos covering the basic topics of an introductory university physics course.
Each program in the series opens and closes with Caltech Professor David Goodstein providing philosophical, historical and often humorous insight into the subject at hand while lecturing to his freshman physics class. The series contains hundreds of computer animation segments, created by Dr. James F. Blinn, as the primary tool of instruction. Dynamic location footage and historical re-creations are also used to stress the fact that science is a human endeavor.
The series was originally produced as a broadcast telecourse in 1985 by Caltech and Intelecom, Inc. with program funding from the Annenberg/CPB Project.
The online version of the series is sponsored by the Information Science and Technology initiative at Caltech. ist.caltech.edu
©1985 California Institute of Technology, The Corporation for Community College Television, and The Annenberg/CPB Project

[@shouryak647]

I am preparing of JEE and CBSE class 12th boards .... This series helps me to get a crystal clear picture of every chapter in my Physics Syllabus. Thanks a Lot Caltech I wish I could study there...

[@kingsurya3215]

Great

[@mahaveervaishnav6348]

So lucky boy

[@antonylawrence7266]

I love these productions, they make you think.

[@alphabeets]

Man, that demo starting at 20:00 is really interesting.

[@difusoseinfinitoslasidorem2241]

Maestros Inst.CALTECH..llevo solo 15.12 seg.escuchando vuestra Exposición Episodio 50..i OS agradesco infinito tanta cordura..tan pensado delicadissimo como un Canto Respetuossisimo a la Natura i TIME i los Genios d la Física i Electro Quantum..a los seres q buscamos la Libertad del Espíritu i de la Biología i Society ..por que Ella como el Arte nos sitúa en un Tiempo " intemporal " de placidez..dulce al alma ..a la mente..y al pobrecillo cuerpo..siempre sometido a su lucha i supervivencia..En vostro Discurso..elegante como los Árboles i el Cielo..con una Música i Sonidos muy muy estudiados i elaborados con fin de suspender leve la mente i sus facultades sencillas i sensibles como Niños o Bebés ..no afecta ni en cripta las palabras sino las deja como pompas de ensueño q mantienen el interés del ser q se acerca a Vuestra Admirable Universal Sabiduría i Erudición..conseguida con sufrido i sufridísimo trabajo ..la Voz del Presentador exquisita i graduada según el Fenómeno descrito..con pausa sin histerias tan de otras latitudes i costumbrajerias..Léo mucho..no hablo ingles..i entiendo Tutto! Por la Verdad i REXPEKT ..fuera del ámbito de las cambiantes Olas i Holas de nuestra humana herrumbre..GRACIASSS..mi primer libro hace años fue..el Sir Gell-Man..i fue fascinante i supe el Instt.Caltech..soy muy feliz..Gracias..unido a Bach i Mozart..i todas las Musas..para bien d la Humanidad..!!!

[@difusoseinfinitoslasidorem2241]

Si..debo agregar con profundo respeto i afecto..mis agradecimnts..al Honorable Profesor David Goodstein..q tan gentil i exquisito explica al nivel riguroso..de los jóvenes i lejanos amateurs de tan SUBLiME laboro i Ciencia la Física Cuántica..

[@sam08090]

Lovely demonstration

[@carlasouza5194]

I would love an updated version of this show....

[@rthelionheart]

The concepts are timeless; perhaps a remastered version of if would suffice.

[@yowinp8075]

Very nice explanation.the old explanation are better than the new one

[@TheSonicSegaNerd]

Narrator: "It isn't really a particle, and it is isn't really a wave. So, what is it?" Me, the next einstein: a warticle

[@Mayank-mf7xr]

17:51 - 19:32 part is fascinating.

[@theevermind]

Re: the end discussion with polarized filters It's not simply a 50/50 chance of being polarized in a certain orientation at the second filter. After passing through the first, vertical filter, the probability of the light aligning with the second (not vertical) filter is a function of the angle difference. If the difference is 0 deg, then the probability is 100%. If the difference is 90 deg, then the probability is 0%. If it is between those values, then the probability is (cos x)^2 where x is the angle difference between the filters. So, yes, at exactly 45 deg, it is 50/50, but the demonstration is just for some oblique angle, not specifically & exactly 45 deg.

[@claytronico]

it seems like one should be able to build a photoelectric transistor, perhaps that has been done, perhaps it isn't possible. I like the idea of playing a guitar amp that uses a light based process to cause distortion. Traditional tubes use two sources of voltage across a vacuum. It stands to reason that if you had sufficient control of light you could build a filter to color a signal, maybe in some new interesting way.

[@philoso377]

The impression plunk has - that light frequency corresponds to the intensity - was rush concluded on face value. No further investigation was recorded on why that is so. What if there is a high pass function to the IR frequency and followed by a low pass function beyond 5000k that we didn’t investigate?

[@oker59]

Heisenberg's Uncertainty Principle was discovered before Schroedinger's wave equation. It wasd Schoedinger's derivation of it that put Schroedinger's equations at the forefront of Quantum Mechanics.

[@davidwilkie9551]

"The new Physics" is the same old particular aspect of ONE-INFINITY Singularity Eternity-now Interval at the Centre of Time Duration Timing, this wave-packaging of QM-TIME Completeness in superimposed Amplitude and Frequency density-intensity interference alignments, ..the entirety of experience is of a focused objective thought about personal self in the Totality of Self Re-cognition, ie conscious awareness of real-time Actuality Conscience Conception. This series of videos is excellent material for review, reiteration-reintegration and reorientation, because Observational Accuracy is a modulo-geometrical log-antilog interference Orientation of Temporal Teaching and Learning techniques to Be Here Now.

[@SpotterVideo]

Quantum Entangled Twisted Tubules: "A theory that you can't explain to a bartender is probably no damn good." Ernest Rutherford When we draw a sine wave on a blackboard, we are representing spatial curvature. Does a photon transfer spatial curvature from one location to another? Wrap a piece of wire around a pencil and it can produce a 3D coil of wire, much like a spring. When viewed from the side it can look like a two-dimensional sine wave. You could coil the wire with either a right-hand twist, or with a left-hand twist. Could Planck's Constant be proportional to the twist cycles. A photon with a higher frequency has more energy. (More spatial curvature). What if gluons are actually made up of these twisted tubes which become entangled with other tubes to produce quarks. (In the same way twisted electrical extension cords can become entangled.) Therefore, the gluons are actually a part of the quarks. Mesons are made up of two entangled tubes (Quarks/Gluons), while protons and neutrons would be made up of three entangled tubes. (Quarks/Gluons) The "Color Force" would be related to the XYZ coordinates (orientation) of entanglement. "Asymptotic Freedom", and "flux tubes" make sense based on this concept. Neutrinos would be made up of a twisted torus (like a twisted donut) within this model. Gravity is a result of a very small curvature imbalance within atoms. (This is why the force of gravity is so small.) Instead of attempting to explain matter as "particles", this concept attempts to explain matter more in the manner of our current understanding of the space-time curvature of gravity. If an electron has qualities of both a particle and a wave, it cannot be either one. It must be something else. Therefore, a "particle" is actually a structure which stores spatial curvature. Can an electron-positron pair (which are made up of opposite directions of twist) annihilate each other by unwinding into each other producing Gamma Ray photons. Does an electron travel through space like a threaded nut traveling down a threaded rod, with each twist cycle proportional to Planck’s Constant? Does it wind up on one end, while unwinding on the other end? Is this related to the Higgs field? Does this help explain the strange ½ spin of many subatomic particles? Does the 720 degree rotation of a 1/2 spin particle require at least one extra dimension? Alpha decay occurs when the two protons and two neutrons (which are bound together by entangled tubes), become un-entangled from the rest of the nucleons . Beta decay occurs when the tube of a down quark/gluon in a neutron becomes overtwisted and breaks producing a twisted torus (neutrino) and an up quark, and the ejected electron. The phenomenon of Supercoiling involving twist and writhe cycles may reveal how overtwisted quarks can produce these new particles. The conversion of twists into writhes, and vice-versa, is an interesting process. Gamma photons are produced when a tube unwinds producing electromagnetic waves.

[@j.cottner6705]

The quantum world is so mysterious and amazing! This mini-verse inspired me to write the charming fiction novel, Quantum Bob: www.amazon.com/dp/B01MA5I4OT

[@satellite964]

I still haven't found a satisfactory explanation why the light gets through.

[@dreamdiction]

Same here. He didn't give any explanation because it's a party trick. All the experiments show that light is waves, never particles. They throw in the word "probability" to make us distrust our own mind. It's a test of credulity, like freemasonry.

[@JivanPal]

@@dreamdiction , the experiment shows that light behaves like a wave. The demonstration of the photoelectric effect and many other phenomena make clear that light comes in discrete packets (photons). The trouble is reconciling the two views: If you agree that light comes as photons, then how do you explain the demonstration with the polaroid filters? The only coherent explanation we currently have is to talk about properties such as polarisation in a quantum-probabilistic manner. This deep-dive on the phenomenon may be helpful: kzbin.info/www/bejne/sJTUi3uPpJyChNU

[@dreamdiction]

@@JivanPal The photoelectric effect is easily explained without light particles, blue light has the right resonant frequency of positive/negative magnetic induction (alternating push/pull) to magnetically agitate a negatively charged election out of it's shell orbit, that's why the photoelectric effect does not work at higher or lower frequencies - nothing to do with "particles". Did you believe red light was waves but blue light magically manifested 'particles' which disappeared again at higher frequencies. You cannot find any slit experiments which show light is particles and the fictional collapse into wave/particle duality. Theoretical physics (including relativity) is called "theoretical" because it is a belief system, like theology. If you think photons exist tell me what shape are they and what are their physical measurements? Don't say photons are wave shaped because that is admitting electromagnetic radiation is waves at all frequencies, never 'particles'. There is nothing probabilistic about a polaroid filter which simple a grid of vertical slits which allow vertical polarity waves through but block transverse polarity waves.

[@dariuslegacy3406]

​@@dreamdictionNever seen a comment so boldly confident in my life. Different atoms have different ionization energies (as proven by experiment). So different materials require different wavelengths of light to liberate electrons. Blue light, which covers a range of wavelengths, doesn't have a monopoly on ionization energy, cesium has an ionization energy that's squarely in the UV range of the spectrum for example. The more likely explanation is that our incessant need to impose our conceptual categories onto the workings of reality has its limits. Is light a particle or a wave? it's neither. It's something else that, under varying circumstances, can be described by the conceptual approximation of either particle or wave dynamics. That the most successful and coherent theories needed to account for both of these aspects which, by our very limited capacity for understanding, seem so very different means the concepts of particle and wave mechanics alone aren't rigorous enough to describe light or electrons(which despite being elementary particles, also exhibit wave like properties).

[@dreamdiction]

​@@dariuslegacy3406 The physics of matter (fluid dynamics) was well understood, the physics of electromagnetic waves was also well understood (Maxwell etc). Theoretical physicists imaginatively speculated by applying the physics of matter to waves and applying the physics of waves to matter - this is where all the wave/particle nonsense comes from. On KZbin there are hundreds of replications of the slit and double slit experiments but not one of them ever shows light behaving as particles, only as waves, but people believe that photons exist so they think they are viewing matter behaving as waves when there really is no particles - only wave behaving as waves. Schrodinger made up his cat-in-a-box analogy to describe the absurdity of state vector collapse, a few months latter he was astounded to see his cat-in-a-box idea being used to describe how quantum mechanics really works. The same thing happened to Lorentz after he invented mathematical "transforms" to describe the visual illusion caused by the fixed upper speed of light giving a different view to observers in different locations (Lorentz Invariance). Einstein copied Lorentz but Einstein said the illusion was REAL because Einstein was autistic so he didn't understand that subjective perception inside the mind does not change objective reality which exists outside the mind. All the so-called experiments which are claimed as proof of relativity and QM have other explanations which do not require relativistic or quantum mechanical ideas. All the experiments which are claimed as proof of relativity and QM involve passing the data through a 'black box' process of speculative interpretations which gives you the fake result you wanted to find. Quantum mechanics and Relativity manifested from nothing like spectral ghosts in mist because theoretical physicists just made it all up by claiming to have measured things which are unmeasurable (like LIGO) and by inventing rhetorical theories which are impossible to experimentally disprove because they made the giant irrational leap of analyzing matter using the same formulas which they devised to analyse waves. That's all QM really is, pretending matter is waves and then claiming that matter has mysterious "wave-like" properties. Space is measured with a ruler and time is measured with a clock, the two can never combine into the fictitious substance called "spacetime". Light has no mass therefore it cannot be bent by gravity, so Einstein invented the nonsense that gravity bends the space which light travels through. Einstein's theory of gravity is insane because Einstein was autistic. Imagination unrestrained by reality has turned cosmology into a belief system like religion which requires 'faith' to believe it. Faith is only necessary because there are no supporting facts, modern physics requires faith for you to believe it because for more that a century modern physics has been polluted with the same post-truth post-modernism which has used moral relativism to detach the mind's of young people from reality and make them easily manipulated into willingly participating in their own self-destruction.

[@GoatzAreEpic]

I don't like the logic in : it must be a wave because only waves behave in this manner. Maybe it's something else which we don't know of yet? How can we be so sure it's really wave-like?

[@whirledpeas3477]

Unfortunately nature doesn't care what you like.

[@theevermind]

You are correct. The better description is: It is NOT a wave. It is NOT a particle. It moves like a wave, and it interacts like a particle, but it is something different.

[@philoso377]

Incidence uV radiation discharge a charged gold leave, nothing was said about it was positive or negative charge, how many cycles the experiment will last or reach saturation point or was the gold leave places in a vacuum jar or not. Is that casual science? We have more than one way to explain the disappearance of discharge. Example : It is well known that uV light can do work - convert oxygen into ozone oxygen and use up that charge.

[@JivanPal]

The results of the experiment hold in a vacuum.

[@philoso377]

@@JivanPal vacuum? You may be right. But it was not reported.

[@JivanPal]

@@philoso377, not reported? What on earth do you mean? This is a classic classroom experiment, it's done routinely.

[@philoso377]

@@JivanPal not reported in this video, made it a casual science report.

[@JivanPal]

@@philoso377 This is a series that was broadcast by PBS for the general public. None of it is particularly rigorous.

[@whirledpeas3477]

FYI, Photons don't need us. Be nice

[@douglasstrother6584]

Wave and Particle Viewpoints www.feynmanlectures.caltech.edu/III_02.html

[@qualquan]

better but rather superficial

[@tomsaxton9534]

but the particles have to bend In curved lines to accommodate the wave fiction.Its like they know they are supposed to be a wave

[@pexfmezccle]

No they don't

[@lidarman2]

The video is lagging the sound. It is enough that it might as well be removed because it ruins the educational experience. Jeeze, you are Calech! You can figure this out, right? If not, send the videos to the university of New Mexico so they can fix them for you.

[@Dismythed]

"Theoretical perfection of the new physics"? What hyperbole! QM's graveyard of dead theories looks like the Arlington National Cemetary next to Classical Mechanics' family plot.

[@JivanPal]

What makes you say QM is a dead theory? On the contrary, it explains all real-world phenomena more accurately than anything that came before it.

[@Dismythed]

@@JivanPal Please reread my post carefully. I did not call QM a dead theory. It has its uses, but the problem is that most physicists have bought into it as the end all be all of physics. It's not. It is nothing more than probability theory and needs to be respected as such.

[@JivanPal]

​@@Dismythed, *_"I did not call QM a dead theory."_* - "QM's graveyard of dead theories looks like ...". Sorry, what does this mean, then? *_"the problem is that most physicists have bought into it as the end all be all of physics. It's not."_* - On what grounds do you say this? Do you know of something better/more accurate? Even if it is true that QM is not the "be all, end all", what does it matter either way, and why would it be a problem if contemporary physicists perceive it as such? *_"It is nothing more than probability theory"_* - What are you trying to say here? Probability theory is a branch of mathematics. Quantum mechanics tells us that things are intrinsically probabilistic in nature. *_"... and needs to be respected as such."_* - Do you mean to say that it does not deserve respect? If so, then again I ask why you think this? What is it about QM and prob. theory that makes them so undeserving of respect in your opinion? Moreover, what do you even mean by "respect" here? Do you mean to say that the findings made in these areas of study are not useful?

[@Dismythed]

@@JivanPal You are interpreting my statements how you like. My graveyard statement was accurate. A useless application of any theory, regardless of its usefulness in certain areas, is going to give you a useless result. QM is not "accurate" because it is only probabilities. A probability, by its very definition cannot ever be "accurate" except by analyzing a cloud of results. It can never give you a single "accurate" result. That is all I have to say.

[@JivanPal]

@@Dismythed, I am merely telling you how I interpreted what you said. I asked for clarification, but whether you do so or not is on you. *_'A probability, by its very definition cannot ever be "accurate" except by analyzing a cloud of results.'_* - That's not what probability is, but in any case... QM says that underlying probability distributions are all that we can known about the universe. In fact, it actually says that wavefunctions are the fundamental thing, from which probability distributions and wavelike interference patterns/behaviour emerge. But what of this? Why do you take issue with this model, despite it being a greater predictive tool than any other we've devised? You do get a single accurate result: you determine precisely what the wavefunction will be in the future based on precisely what the wavefunction is now. The trouble is that the wavefunction, while itself precise, does not correspond to precise knowledge of things such as position and momentum. But again, what is the problem with this fact? Clearly it doesn't sit well with you, but why?

[@fjs1111]

23:34 -- Is that @Sabine Hossenfelder lol?