Quantum Theory

I just watched this rather interesting TED video ( https://www.youtube.com/watch?v=1RWOpQXTltA), which dicusses Plato's allegory of the cave. It occured to me that it is also a good analogy for our difficulty in reconciling our perceptions of the macroscopic world and the quantum world. It almost perfectly fits that the shadows are the normal world we observe and the objects and light outisde the cave is the quantum world, especially since the quantum world is just that, light (gauge bosons) and objects (matter), and the shadow it creates of the macroscopic world is that which we observe through our macroscopic human senses. While both worlds are real, one precedes the ot…

Well, aside from Quantum Physics changing, everything would fall apart, planets would stop spinning and orbiting. Yea.

If the wave state of a particle is collapsed when observed, if we stop observing it does it change back?

How often is division by zero found, when merging mathematical statements of classical and quantum representations? I know of at least one, that is black holes.

Am I correct in the following statements on particles. 1. It is that an electron is a particle that behaves like a wave in certain instants within it's "orbit" of the nuclei. 2. A particle in the state of superposition is a wave that in certain instants behaves like a particle, in more than one place. 3. A photon is a wave that at certain instants behaves like a particle in one place at one time. I am short of "nuts and bolts" education in this regard (equations), I can only pose question in philosophical forms, my apologies.

I would like to understand classical spin and quantum spin with regards to particle spin filters - I seem to be missing something fundamental on how they are used / work. Starting with the classical understanding of spin, the set up is as follows... A particle has an axis of spin along the vertical z-axis and it passes horizontally through a particle filter that only allows particles through with a vertical axis of spin, say to an accuracy of 5 degrees either side of the vertical. After passing through that filter, the particle goes through the same type of spin filter, but this time the filter is set at 45 degrees from the vertical z-axis (but the filter is sti…

I am studying Srednicki textbook on QFT. I don't know how to compute effective (quantum) potential in \phi^3 theory with 1-loop. Thanks

These are the ideal theoretical requirements of quantum gravity. Notice that this gives us much more than quantum gravity, doesn't it? The true requirements of quantum gravity are: 1) Invisible and visible space in fundamental equilibrium and balance. 2) Fundamentally balanced and equivalent attraction and repulsion. 3) A space that is stretched/expanded and contracted/flattened in balance. 4) Fundamentally and ultimately equivalent and balanced gravity, inertia, and electromagnetism. (See how this is fundamentally consistent with 2) ? 5) What is the middle distance in/of space. 6) A larger space is made smaller, and (on balance) a smaller space is made larger. 7)…

Hello everyone and thank you for accepting me into your Group. My question is short but probably quite complicated..... Do Quarks (or Hadrons) contain enough energy to excite a current in a coil?

just now having watched a "physics documentary" called "the Universe" final episode of final season (on Netflix currently) called the microscopic universe. The widely reknown "double slit" experiment was discussed or as they called it "double hole" experiment. This documentary was made in 2007. Let me ask first...does the notion of the consquequnces of the experiment still produce the idea that a particle could exist in two places at once due to the "strange" "against common sense" "spooky" world of "quantum physics". Let me ask second...has all the technical understanding of why the experiment results are dependent upon whether or not the experiment was being observed?

From Wikipedia: Bell's Theorem draws an important distinction between quantum mechanics (QM) and the world as described by classical mechanics. In its simplest form, Bell's theorem states: “No physical theory of local hidden variables can ever reproduce all of the predictions of quantum mechanics.” When trying to understand why the above is true, I find it difficult to follow the explanations without a classical particle to use as an example. I would like to step through Bell’s Theorem using a classical particle, albeit a hypothetical classical particle, but nonetheless a classical particle. The purpose of this post is to understand how Bell’s Theorem p…

Assuming there are multiple dimensions -- If the universe stops expanding and starts contracting, would this event affect one dimension, select dimensions, or all of them?

How are subatomic particles classified into the following: 1. Leptons 2. Mesons & 3. Baryons ?

Hello everyone and everybody! What about a slightly exotic idea? Here I propose to measure the "effective" mass of charge carriers by centrifugal force. Electrons in vacuum have a mass, and when moving in a solid an other mass, often called "effective" (as if the vacuum mass were ineffective). Centrifugal force creates unequal voltages across dissimilar materials that give a different mass to electrons, and with a proper setup, this voltage seems measurable - which I feel funny. Along a radial leg, the centrifugal force creates a voltage of mA * 0.5*(V2-v2) /q in the material A, or mB etc in the material B, with V the outer speed and v the inner one. By…

What do I need to "show" as a scientific result for quantum gravity within our solar systems. What I have issues with is the symbology, and the scientific " words" that explain my finds.. Plank units are so easy to understood once you understand the symbols and numbers they associate with. I don't understand this yet, but will soon. My main focus is where Einstein Field Equations " Brake Down," nonsense numbers and infinities found in calculations. I am very skilled and keen in math, piano, number theory, geometry, and art as a hobby. I am very confused on the standard model as per this article: Problems with the Standard Model http://www.sns.i…

After seeing many videos on youtube, I ended up with some questions, many are using theories of quantum mechanics to sustain ideas "new age" "mysticism," etc, IMHO they're all mumbo-jumbo, but they're saying that science support their ideas, is that true? 1. Does Qbism support the idea of 'your mind creating reality'? 2. Do the tests on the Leggett-Garg inequalities debunked macrorealism ? 3. Even the nucleus [of an atom], which we think of as so dense, pops in and out of existence just as readily as the electrons do" ? I appreciate any help that you can provide, thanks!

Hey I have been absent because I am coming to the end of my final year in physics. I recently got an 89% in my last quantum mechanics. I’m hoping to get a 1st so I can do a masters in physics at UCL. However, I do not understand a certain concept. Why do angular momentum operators (including the Hamiltonian) always leave non-zero answers? Looking at hydrogen (simplest for this sort of thing) is there a certain characteristic that these operators have that result in a definite non-zero state? Does this change with state? So do hydrogen atoms have definite non-zero values no matter what state they are? I’ve tried to read round the subject but I never get a straight answer. …

In the wikipedia entry on wheeler's delayed choice experiment, a description is given of a simple interferometer set up. The article says (if a second beam splitter is not present): "Observing that photons show up in equal numbers at the two detectors, experimenters generally say that each photon has behaved as a particle from the time of its emission to the time of its detection, has traveled by either one path or the other, and further affirm that its wave nature has not been exhibited." What about the experimental results rules out interpreting that the photon has travelled in a wave like way as opposed to particle like way?

Hi! I am a photography student from Argentina, with no knowledge of physics or math. I like learning what I can from the cosmos on the internet. Lately I’ve been very interested on supersymmetry, string theory and entanglement. I saw a class by Leonard Susskind about black holes on YouTube were he states that two particles are entangled, one inside the black hole and the other one outside. What I could understand about entanglement is that when you make a measurement on an entangled particle you know that the reading on the other particle is the opposite. So, my question is, how do physicsts know which particle is entangled to which particle, as in how do they know that t…

Hello All, Here and there is talk that many worlds/multiverse cannot be tested. But what about Elitzur-Vaidman bomb test in 1990s? Hasn't it demonstrated validity of this interpretation? Please,read this interview with Lev Vadiman,one of the prominent advocates of MWI,where he talks that in this experiment communication between universes took place: http://joehubris.com/node/78 - and let me know what you think.

Hello All, This is quote from Wikipedia entry if Many Worlds Interpretation of quantum mechanics Quote: So,we live in false vacuum and is indication of many worlds? Any thoughts?

This was discussed recently. Here's a really good video that just came out explaining the situation with entanglement and Bell's theorem. This walks through the scenario described by a link Strange had posted in another thread — what the correlations need to be for a hidden variable system with the detectors at 0º, 120º and 240º, what they are in QM, and in experiment.

I can't really understand electron spin. Is it rottation along it's axis ? Thanks !

---------------------------Newbie Alert! ---------------------------------------------- I was thinking that so far we have not been able to confirm anything as random. We have been able to put an equation behind nearly everything we have discovered, quantum physics is an exception at the moment but soon we will uncover it too. If it is true that there is nothing random in the universe then all events that occur do so at 100% probability because when you factor in all the variables the outcome can be predicted surely. So we no longer need a multiverse to explain all the possible outcomes because technically there is only one outcome. What do you think?

url deleted