Reality Definition and 494 Threads

Hi, I have a silly question, Could one, in theory make a accurate model of the life of our universe that one could look at from within. Let's say I put on my VR/AR goggles, 'there' Iam elevated from the earth, then I remain static, and the time begins to rewind. At some point I maybe hear...

The gear ratio is the ratio of angular displacement, angular velocity, angular acceleration, torque etc of the input with respect to output. However, I would like to know that which of these variables will be scaled exactly to the gear ratio in reality, as there might be some friction in the...

In the Wilsonian viewpoint, quantum electrodynamics is an effective theory, where the low energy predictions are obtained by coarse graining eg. some form of lattice QED where the lattice is taken very finely. In the Copenhagen interpretation, we are agnostic as to whether the wave function is...

Hi Do Quantum Mechanics negates the reality of matter and proves un-reality of matter ?

Interesting new work on the link between quantum state vectors are physical states: Can different quantum state vectors correspond to the same physical state? An experimental test Daniel Nigg et al 2016 New J. Phys. 18 013007 Abstract A century after the development of quantum theory, the...

Hi, I’m new to the forum and I would like to ask some questions. I’m not a physicist –for some reason that I’ll always regret I chose Business Studies- and my knowledge of physics is limited to high school, physics books and documentaries; which I must have watched them all by now. Anyway, for...

(I apologize beforehand if I'm asking such an 'amateur' question , I admit that I'm not a physics student / physicist nor scientist / science student ,.. but , as just a 'normal ordinary' person, at least I am very interested in these things ,. and how I deeply wish Humanity / Mankind can 'leap...

While learning about SR, I encountered the famous Minkowski spacetime. At first I thought it was just a useful mathematical trick, with no particular physical meaning. But reading more about it, it seems that this notion of spacetime is often (always?) regarded as the actual physical reality...

As I understand it, the standard spacetime model is a 4-dimensional geometric object, and that my personal history is just a particular curve in the model. Reality as I experience it though is that I move through time, and thus I have the concept of the present in which "now" corresponds to the...

The other day, in conversation, I attributed the dictum, "If you can't measure it, it isn't real!" to Lord Kelvin. However, when I chanced to look it up in Wiki, I could find no confirmation of this attribution. Was I mistaken? Did Lord Kelvin ever say anything to this effect? If not, is...

According to quantum physics, things don't exist until being observed/measured. If this is the case why can we predict the same reality being generated? For example, if the moon doesn't exist when it is not looked at, then why does the moon keep appearing when we do look at it. Is "reality"...

Hey there! So I have this circuit: with R= 1kOhm and L=10mH and for some reason the theoretical and real values differ drasticly for lower frequencies Brown lines are representing the asymptotic and approximation lines. Blue lines are connecting my measured values. Amplitude is the amplitude...

If the infinite monkey theorem provides proofs for the probability of order's emergence from chaos, is there a way to measure the probability of order in our universe i.e. matter/anti-matter, snowflakes, DNA? I just wonder because if there was, you could compare the two values and see if we...

So basically, I'm sure many of you have watched the new tv show Mr. Robot. I'll be the first to say that the show is incredible and quite possibly one of my favourites ever. And if you haven't watched it you should. But that's besides the point. It seems the show has inspired many non-tech...

Someone I know sent me something for validation. Is this train of thought headed in the right direction? Please forgive him for the informal language used; he doesn't have a physics background...Thanks! "Superposition simply implies that conscious beings always have choices, and that...

I was watching a Twilight zone episode yesterday . A spacecraft had crashed at a 'remote far corner of the Universe'...550 million miles from Earth (not even the distance to Saturn). Today I was reading a comment that complained about a local bottling company selling bottled water and using...

AFAIK black holes are factual, but i can not find physical proof of the singularity, apart from Einstein's theory of general relativity, which showed that when a massive star dies, it leaves behind a small, dense remnant core. If the core's mass is more than about three times the mass of the...

Does something in QM suggests that "everything is happening, here/now at once? Is there any evidence to prove it? (quantum reality) I saw a video about it on the internet, I will not post the source, because I think it is pseudoscience, but he confirmed that QM proves it..lol Please, I don't...

Hi! I'm an Indian student from the CBSE curriculum in 10th standad (started a month ago). I want to do under-graduation in Astronomy / Computer Sciences / Robotics / Mechanical Engineering (still not decided yet. But it'd be much better if I can able to study all of them together :p) in any of...

Hello PF, A question on special relativity I've not found an answer to,I tried to google it but no luck, so here is it : If you were to observe a moving body whose speed is very near to the speed of light, will you see it slowly due to time dilation, or you'll observe it as it really is, very...

Why does some physicists say that consciousness is the "Ultimate reality"? which experiment affirm it? Some like 'Tom Campbell' uses Data Eraser Experiment as proof, and quotes from "Max Planck, Bohr, Heisenberg, etc.. as references SOURCE: Is it true? What is "consciousness", anyway?

Hello everyone, (Hope this is the right place to post this) I am wondering, and have for a while, if there is any "real" answers, as to why some people report much lower fuel economy running ethanol mixed gasoline fuel. Math says, that ethanol fuel is lower in BTU's than gasoline, so taking...

I am reading the book Road to Reality by Roger Penrose. However he goes over the maths so fast I don't understand it all, I am studying maths and Further maths and getting over 90% almost all the time so maths normally comes quite easily. What maths topics do I have to know - the contents...

Hi everyone, I'm a sophomore in college and we have a project discussing mechanical engineering. I'd like to know what you thought your career would be like before you graduated and now that you're in your career what is the reality. Addition questions: How long after college did you wait for...

Lets suppose we have a observer O and two objects A and B a speed is 0.5c and B speed is 0.3c than we can calculate other relative speed acoording to these informations.We know that (according this info B sees A going to 4/17c but we can pretty sure that's true because we can't ask. him How...

Homework Statement Homework EquationsThe Attempt at a Solution could you give me the reason for part i. Can't figure the reason for the second part. it says ans is 1080N to left. shouldn't it be 900N. and why is it to the left?

For those of you who have read the theorem, probably have also read Matt Leifer's review of it. In his review he says that the only way to remain psi epistemic is to be an anti realist(copenhagen), or to abandon the bell frame work. Is it viable to be psi epistemic but still believe that...

I am still learning of Kaluza-Klein theory. Is KK theory applying to quantum mechanics? How quantum non-locality can be represented by KK theory?

Several recent arxiv articles like http://arxiv.org/abs/1409.6290/ reviewing the pbr theorem http://arxiv.org/abs/1111.3328/ got me thinking about this again with respect to straightforward two-slit interference, which I'd thought simply and unambiguously resolved the issue in favor of "it's...

It will essentially be The Matrix. Except every one who plays will be God's and they get to build the world up from atomic structure. The main mechanism of action is people finding stable formations can publish them. You get to name an object and it becomes available as a clip board item to...

A magnetized object is always described as having bound volume and surface current. Are these bound currents real? I mean if I connect a galvanometer between two points on the surface of a magnetized iron sphere, will the galvanometer show a deflection? If it does then it is very strange because...

Another theorem ruling out ψ-epistemic models: http://arxiv.org/pdf/1412.0669.pdf

What does quantum mechanics say about the nature of reality? I have a friend who's been babbling about how he thinks given the right circumstances (meditation, LSD, the hokey poky, take your pick) you could create "personal reality" and I don't know enough about it to say precisely why he's wrong.

Is Space time having a actual reality or is it just a mathematical concept to calculate the coordinates of a point in space?

I want to become a mechanical engineer. Im not good at any sciences or mathematical subjects. I got E in physics and maths AS level (http://en.wikipedia.org/wiki/A-level), D in computing, B in philosophy. The humanity is the only subject I am good at but even thought I enjoy listening...

I just wanted a conformation of this sorry but I have bad ocd. If I could have some sci advisors help with this id really appreciate it.

There is an old controversy in quantum mechanics, with arguments on the borderline between science and philosophy, on the question whether the quantum state describes an objective reality associated with a single system, or mere probability describing properties of a large ensemble of equally...

We measure time based off of atomic vibrations, so time dilation from gravity and velocity are nothing more than pressure applied to the atoms, slowing their vibrations. This isn't an accurate measure of what we consider time, but more of a measure of the reaction of atomic vibrations under...

If a charged particle is at rest, external magnetic field cannot move it. If an external electric field is applied, the particle will get accelerated. Now the external magnetic field will exert a force on the particle perpendicular to its motion. This will change the direction of motion of the...

Coming from a Chemistry background, the Uncertainty Principle always seemed to be described as an inability of precision due to strictly physical and real reasons (i.e. you have to interact with an object to measure something about it, and this certainly will alter the object). It seems as if...

Does block universe mean that time and motion are illusions?

Hi! I was wondering that if you could put enough electricity into a superconducting coil if it would be powerful enough to bend space?

I want to know how much energy REAL steam compressors consume in compressing steam @ 1 kg/sec from 2.56 kPa to 1 bar. Theoretically (with `100% efficiency) it's 141 kW for making 1 kg/sec steam flow assuming that the temperature doesn't decrease due to loss of heat as latent heat of...

As we know that in classical world we have a clear arrow of time which points towards future..We can see glass falling from table and break but not the opposite in our world and whole universe... If we watch a film of glass being broken and that film is run in both direction we can easily...

Hey guys, my wife and I are writing a short story and I wanted to perform a reality check on the following scene and see what changes might be needed to make it possible. In the scene we have written the main character has enhanced speed and strength and she gets attacked in her home, during...

Hi all, I apologize in advance for a bit of a lengthy preface on my question. I'm a PhD student in computational condensed matter (with a specialization in parallel and high-performance computing) who's just finishing off my degree. I don't want to continue in condensed matter...

Hey everyone, This has been bugging me for a bit. I think I'm probably missing something pretty easy. A dot B= ABcos(θ), where θ is the angle between A and B. There is the little shortcut that says where B is the derivative of A, A dot B= AB. Clearly then cos(θ) = 1, and the angle between a...

In universe we afffect everthing.Observers (us) measures something and we changed something.Example If we want to measure a electron's momentum than we can't measure its location Physics says this is real so it means it is not an experimental mistake.How they know it.How can physics says that...

Is there an absolute sequence of events in the universe- independent of observation? It seems like so much emphasis is put on our delayed observations rather than what is actually happining in Reality. As I read through the forums, it almost seems as if people do not believe that there is an...

After reading Lee Smolin's Time Reborn and Rodney Brook's Fields of Color, a question occurred to me. Has anyone compiled a "reality" scorecard for the differing theories out there, both current and historical? For example, QFT proponents would consider the following things as real: fields...