Quantum Theory

Very often people come to these fora with a belief that our current theories of physics, such as the Standard Model or relativity, are flawed and present some alternative of their own. On the whole, this is a fine attitude to take - we should always be skeptical, and it is good if people can think a little 'out of the box' and generate ideas which more standard thinkers may not have come up with. I have always thought that genius was not an ability to think 'better' than everyone else - it is an ability to think differently from everyone else. However, when coming up with a new theory it is important that it should be better than the old one. Therefore the first step …

Hello, I have read many posts where I find the above expression (Most notably from Mordred) but I only encounter it as part of explaining some other topic. Could you please expand on this with more information? It is a really interesting subject for me.

All the typical weirdnesses of QM - the double slit experiment, observation collapsing the wave function etc. - are they still regarded as mysteries that need to be resolved, or is the view now that that's just how the universe is and there is no explanation beyond that?

What evidence is there to support the suggestion that time is continuous and not granular, or vice versa, or both, or neither, or something else? What evidence is there to suggest that relative-frame-of-referenced simultaneous events are a reality? How do we measure two simultaneous events and declare they are simultaneous if all observables and measurements are ultimately limited by HUP? We may synchronise two atomic clocks, but how do we know they are synchronised without measuring them and how do we know after our measurement they are still synchronised? How can we be certain at the time of measuring two events, that the clocks were synchronised? In a volu…

Can photons or other particles form a wave-function again after an "observation" or "measurement" and what determines when or how that happens. So for example, we attempt the double slit experiment, where we have a measurement device at/before the slits, and have thus collapsed the wave-function, leading to 2 lines and not an interference pattern. So if we put the screen further away, then add new splits, would we at some see an interference pattern again? I hope that my question itself is clear, in case there are technical reasons why my above experiment wouldn't work. Thanks!

Has it really been shown that probability laws would work under MWI? Anything that can theoretically happen under the laws of physics would seemingly have a probability of infinity/infinity of happening under MWI.

I am quite confused... A cat cannot be alive and dead at the same time, essentially what Schrödinger was trying to prove.. A state can collapse without a conscious observer. How did so many people misinterpret his thought experiment? Or am I missing something here?

the aim of this thread is to gather essential information from all quantum gravity-related threads into one, to get some focus Links to other SFN threads will be provided, and links to outside sources Smolin: How far are we from the quantum theory of gravity? http://arxiv.org/abs/hep-th/0303185 Rovelli: Quantum Gravity Cambridge Press 2004 http://www.cpt.univ-mrs.fr/~rovelli/rovelli.html Smolin: Invitation to Loop Quantum Gravity http://arxiv.org/hep-th/0408048 Ashtekar Lewandowski: Background Independent Quantum Gravity; a Status Report http://arxiv.org/abs/gr-qc/0404018 Smolin: Scientific Alternatives to the Anthropic Principle http://arxiv.org…

I find this subject interesting , yet at the heart of quantum theory. If anyone has any eureka feelings about " spin" at the quantum level please could you share them !

the question that dwells on almost any physics professor, of philosopher's mind is "Is time travel possible?" Well, why shouldn't it be?? We all are in fact time travelers ourselves. We all move forward in time, well, at least we all perceive to be moving forward in time. In fact, when you really think about it, we could all be moving backwards in time...time may not be moving at all. It could be stopped at the very moment that I am writing this...Of course you'll say "that's impossible, if time has stopped, how can I be reading this??" but we are forgetting the fact that maybe time has stopped for someone else. After all, time travel has a lot to do with perceptio…

I don’t know the math behind time, but I feel that time is something that is always changing. So to try to come up with the math that makes it work with all the others I feel is the lack of understanding. I want to look at it as if it was sound. Sound when it goes out and comes back gets weaker every time until a new sound is added. So can time change the same way as sound. If this is the case the more you are always from an object in time the less it effects time. The same as sound gets weaker as it moves as does gravity. So if you wanted to bend time would not you only have to mass the effects that objects have on other objects. To me time is like a river if you place…

It is when the player (or game character) looks at something. The GPU then instantly responds by loading the object / surroundings in question. Well, if we assume that reality is virtual, there is nothing counter intuitive about the observer effect. It's actually the only scenario in which it makes perfect sense. I guess it's all about how the evidence is interpreted. To me the collapse of the wave function is valid evidence of a virtual universe, just like Brownian motion is evidence of molecules. I should also mention that I used "commonsense reasoning" as a pun, because it is a strong AI term 😁

The stopping voltage is the voltage that one would apply to stop the electrons from migrating to the cathode. My quest is what purpose does this serve and what does the stopping voltage tell us?

LIGHT We do know that photons behave like a wave and a particle both, that's what particle wave duality tells us.. 1)So which source of light behave likes a particle and which one like a wave, How do we know that?? 2)If a particle has larger wavelength it behaves like a wave and the one which has smaller wavelength behaves like a photon? 3)Photons have momentum, p=hv/c, do wave have some momentum? Electrons Electrons are present around the nucleus of an atom(we all know that) 4) Are they present there as particles, standing frequency, clouds or on orbits(which is the least i would prefer) ??

In the double-slit experiment, what collapses the wave-function? The act of measurement? The information obtained from the measurement? Or the observer contemplating the information obtained from the measurement? The first is physical, the second informational and the third attributable to consciousness.

Well we all know what events gravity creates : an apple falling from a tree , planets orbiting around the sun . Until the mid 1920's we thought that gravity was the attraction between objects with mass , but Einstein came and said nope : gravity is the bending of space-time around something with stress . Quantum mechanics is the theory that describes the world of subatomic particles , the foundations of you , me , everything . However at its original form quantum mechanics didn't describe how those foundation blocks interact with each other . So some physicists tried to unified Relativity and Quantum Mechanics to describe those interactions. Th…

The new Large Hadron Collider is coming online soon. It is said to be able to create micro black holes. I immediately admit that any knowledge I have about micro black holes comes from the main stream media (including wikipedia), and is therefore not very good. So, I read about the Hawking radiation, which states that the speed at which a black hole is emitting matter (the rate at which is loses weight) is inversely proportional to its weight. According to this theory, the micro black holes are harmless, because they will in fact lose all their matter so fast, that it might seem a small explosion. http://en.wikipedia.org/wiki/Micro_black_holes But, I also read…

First of all.. I posted this thread under quantum mechanics because I think it has something to do with Max Planck,s equation. Anyway.. my text book says that the energy of light depends on it's frequency. Now this has me quite puzzled. In a mechanical wave, such as the wave one could make in a piece of string tied at one end to a fixed object, the energy arriving at the fixed end would be dependent on the amplitude of the wave of the string right? So why is this not true for electromagnetic waves? (I know there are many differences between electromagnetic waves and mechanical waves.. but I just can't figure out what makes the energy of one depend on the frequency a…

I've been searching around for the closest anyone's gotten to absolute zero... I can't find it now (forget what I searched for lol) but there was one dated 2003 that said 500 picoKelvins... I just want to know exactly how close to absolute zero anyone has been able to reach...

I have a question about the shape of the wave of a single photon entering the double-slit experiment, in time and space. Although I thought it was basic, it seems to be difficult because I did try other fora and Wiki, but nobody could give an answer. This is my last shot. Of course the interference pattern shows the shape, the envelop, in time. But because I don't have accurate measurement data (most pixtures of the pattern are simple and idealised) I cannot construct it from there. So I wonder if there is the (rough) formula, only as an approximation. Not exactly, because that will probably be of a high mathematical level.

What frequencies are above gamma rays and what are they called? Also what is below radio waves on the spectrum, and what is it called? Does the photon move in straight lines or the wavey pattern going up and down? When you shut off a light's power source, do the photons keep moving or do they stop immediately? For example you have a real big intergalactic flashlight that is projecting light for well over a year. Then all of a sudden you turn it off. Will the photons that have traveled a light-year stop instantly or will they keep going?

im not really sure what category this should come under but anyway: recently i saw in a newspaper that some scientist had teleported the properties of an atom, they'd teleported things before, but nothing as big as an atom and nothing as complex as an atom either here's a link to a website explaining what they did/found: http://news.bbc.co.uk/1/hi/sci/tech/3811785.stm it says that this is an important break through because althought they are still a long way off teleporting humans, they could use it to teleport data in computers instantaniously but what i was interested in was how they did it... they used a method called 'quantum entaglement', by w…

Theoretically, if an object has 0 kinetic energy, then it would mean that it's time stops, but, that same thing is exactly what happens in measurements in quantum mechanics. When we measure a particle, we are measuring a single finite and "not moving" point, its just a point, and since it's just a point and it's can't be moving because it would mean that your measurement is somehow getting information of it's motion before photons reach our eyes, it has 0 kinetic energy, so couldn't the reason why there's all this measurement weirdness be because a million times a second we are technically "stopping time" and therefore giving something 0 energy, and since it doesn't have …

You can isolate other charged particles, why not quarks? Can it theoretically be done but we just don't have enough energy? Also, why would any particle not be able to be isolated? Aren't gluons or muons inseparable? Is it the same principal?

is the multiverse shown in the Michael Chrition Book timeline real or made up