Reality Definition and 435 Threads

A little about my background. I have a undergraduate degree in physics which I obtained exactly 20 years back. I also have a undergraduate degree in EE which I obtained about 17 years back. I have worked as a software engineer all my life and currently also pursuing my MBA in Finance. Needless...

I started reading Penrose's Road to Reality and really loving it so far. I am just curious - are there other books such as this that do not avoid necessary mathematics but is not really a textbook? I love this format. I also finished and liked Susskind's Theoretical Minimum (first volume -...

Hello, I'm a 25 year old veteran who is currently enrolled in school. I'm curious how many of you think that going after a degree in Astrophysics would be a waste for someone like me. I've just recently started going back to school after finishing my term of service. I am currently going to a...

I know that the theoretical decoherence mechanism makes the density mattrix diagonal, but my question is if that happens in real life. I mean, let's take the hidrogen atom (lets work in the QM framework And not in the QFT framework in order to have multiple stationary states) And suppose that...

Has quantum physics "proven" that thoughts become reality? This is not a homework assignment. When I go to the homework section, none of the links fit because this is a quantum physics question and it’s neither undergraduate or high school related. If this is not the appropriate forum, please...

How can we measure the "reality" in quBits? Hello All matter is based in information, and quantum computing use quBits, so I was wondering how can we measure the reaility in quBits? A certain solid objet, let's imagine an apple, it has a weight and we can calculate (approximately) the number...

I am a bit wary about posting this, as I am pretty sure what the response would be if I claimed this was paranormal or some other weird stuff. So before we start, I do not believe in ghosts, I do not follow religion, I am very much a believer in the scientific method. I am not claiming to have...

Homework Statement I have not been doing Lyapunov for a while and when doing an ordinary Lyapunov problem the other day, I ran into a funny situation. The correct way of doing it: \begin{align} \dot{e} &= \frac{1}{L}(u - R(e + x_{ref})) \\ V(e) &= \frac{1}{2}Le^2 \\ \dot{V} &= Le\dot{e} = Le...

Author: Roger Penrose Title: The Road to Reality Amazon Link: https://www.amazon.com/dp/0679776311/?tag=pfamazon01-20 Prerequisities: High-school mathematics and physics (in principle) Contents:

Hi. First of all English is not my native language and i am a layperson, so I hope i can explain my self. It is said that reality at the quantum level is probabilistic, not determined. My question is : That is really the case or a probabilistic knowledge is the best we can get as humans...

Hi I just finished high school and want to study electrical engineering in college. My dream is to build a virtual reality machine of my own. Any advice on which area of electrical engineering that I should specialise?

Are SM particles expected to really be i) simple excitations of their associated fields, ii) particulate matter which happens to be very conveniently (and precisely) modeled as excitations of such fields or iii) we can't judge one way or the other in the present state of our knowledge? If they...

According to GR is space actually supposed to be bending around mass, or is the concept of "curvature" just abstract and purely mathematical idea?

One of the postulates of QM is that the physical state of any system (with any number of constituent particles) corresponds to a Hilbert state vector ψ. So an isolated system that includes an object to be observed, the observing apparatus, and also the human observer himself is also represented...

Citing a recent post from Dr. Chinese, it seems like quantum entanglement experiments are showing something beyond the current standard model. https://www.physicsforums.com/showthread.php?t=637454 If particles can be entangled to other particles that only existed in the past, it seems that it...

I know why I don't watch them cause they're crap, and I don't get the point of being famous for having no talent, but just curious if people with scientific backgrounds and higher education enjoy them?

Homework Statement Inertial frame S' moves at a speed of 0.6c with respect to frame S. Further, x = x' = 0 at t = t' = 0. Two events are recorded. In frame S, event 1 occurs at the origin at t = 0 and event 2 occurs on the x-axis at x = 3000m at t = 4*10-6 s. According to observer S', what...

I'm just curious and like thinking about how reality works. I don't now where or if I could find the answers to these questions already written. From what I've seen and read, gravity is cause by space being bent by mass the same way a person standing on a trampoline bends the trampoline. 1...

I found this site via a google search for some key terms I was thinking about. Let me preface by saying I have never taken a physics class, and I am definitely no genius. I formerly was an intelligence analyst in the military working with electronic signals, the concept that I'm now pondering...

The Unruh effect claims that a quantum state which can be defined as an "empty vacuum state" by an inertial observer will become a "thermal state containing particles" for an observer with constant acceleration a; the temperature observed is T ~ a. In contrast to other oberver dependent...

Hi, I am a college sophomore who is currently headed down a biomedical engineering track. Though I was always somewhat fascinated by space, all of this returning hype about space travel and space mining has really sparked in me the desire to help as much as I can with such proceedings. How...

Do share your thoughts on this statement.

Hi! I'm currently reading 'An Introduction to the Philosophy of Physics, Marc Lange' where he is arguing about the reality of the electromagnetic field etc. While reading I caught myself in not having the concept of what that makes something real in place. How would one define something as a...

What is the scientific understanding, and what are peoples' personal opinions about the nature of "reality" Are we living in a reality where everything is basically solid, real, and for the the most part definable by the classical laws of physics, with the quantum world of entangled particles...

I’m not sure in what is the best way approach this topic in-order to stay within the forum guidelines but I hope I’ve done so. From the recent moderator actions, this topic it is too far removed from the philosophy of mathematics to be part of that thread. The basic question is whether existence...

Hi, So I have taken a math course dealing with the mathematics behind GR. In it I learnd how to calculate many of the objects that GR deals with such as curvature tensors, geodesics and so on. However, not much physical explination into how these object tie into gravity was discussed (due...

Question about the "reality of the quantum state" paper by Pusey, Barrettm and Rudolp In the paper I mentioned in the title (on arXiv and supposedly subsequently published in a journal), the authors claim to show that "if a quantum state merely represents information about a system, then...

This is my first post, so forgive me if I'm posting in the wrong place or violating a rule. I've been doing some reading on relativity, and find myself flummoxed. I understand gravitational time dilation and the principals behind relative velocity time dilation, length contraction, and the...

Hi all, I have a little out of track question and I was forced to consider this after reading FQXI Essay competition title Is Reality Digital or Analogue and Kant's Critique of Pure reason simultaneously. If I am not wrong, according to Kant, there are limits of pure reason. Is not the...

A lot of people keep recommending this book, I have it but I'm a little skeptical about trying it out. I want to do the hard calculations and master them whereas it seems this book just tells you what's out there, it doesn't show you how to master the subject matter. However, it's really hard...

I have no idea about it, as my understanding,that Mr.Einstein depicted that what actually happening in space are above on a plane and flat Space-time fabric.Is this telling us that the Earth around is nothing ?What i trying to say is the surrounding of a mass might not exist only a plane of...

In SR the points in Minkowski space correspond to events. I recently read in a GR lecture note that the points on the manifold do NOT correspond to events like in SR (the author even says the points don't have a direct physical meaning). So what do they represent then? And if I continuously...

What is energy in reality, is it PHOTON?? When mass is annihilated, two photons or light is produced. That light has very high(or highest) energy level. As the energy of light depends on it's frequency and wavelength it means that photons are not energy themselves but just energy carrier(gauge...

what does it mean.

when i think of a particle standing still, i look at it as if it were moving through time, propagating a wake, the wake representing its information propagation. the farther you are from the particle, the longer it will take the wake,travelling at c at its fastest to reach you. because...

I could really do with some consultation here This is mainly to do with reality , being , awareness and meaning for humans. Can we agree reality is one thing and our awareness of what reality is another(- so that is almost a separate reality as we know it)? Im having a mental block at...

On this page : http://www.ipod.org.uk/reality/reality_quantum_casino.asp the guy present a function like this : ψ = A cos(x) then he says according to Euler formula, which is e^ix = cos(x) + i sin(x) : ψ = A e^ix ?? shouldn't the result be instead : ψ + A*i*sin(x) = A cos(x) + A*i*...

Question: Greene's "The Hidden Reality": the holographic principle On pp. 260-261 of "The Hidden Reality" Brian Greene says the following: I puzzled over this for quite awhile and it seems as though Greene, probably inadvertently, phrased this somewhat more decisively than is justified - that...

Preparation to "The Road to Reality" Hello everyone, Sorry, I know it's not the right section but I can't post in the "Math & Science Learning Materials" forum. I read really good reviews about Penrose's book "The Road to Reality" and I will probably purchase it, but I also read that the...

Hello all! In the past few months I've stumbled upon an issue that has played games with my mind. I feel I need some help to solve this, as I've tried various other sources and remain without answers. Firstly, I was confronted with a mathematical proof which states that 0.9~ (to infinity)...

Hey all, I'm working on a short hard-sci-fi story, and I'm a bit unsure of the foundational accuracy of my work. If anyone is willing, I'd appreciate some critical analysis of some of the appendices, to either make sure I'm kinda on the ball as far as accurately portraying the concepts go, or to...

So I've been reading a lot about Bell tests. I have a question that I can't seem to find an answer to. The tests indicate that a photon decides to be horizontally or vertically polarized at the moment of detection. What are they basing this on? To make such a counter-intuitive assumption seems...

Someone suggested to me that this stuff may be more appropriate in the QM section (I’m not sure?). I think others on here have brought this up before but I thought I’d post some stuff I’ve come across that may be useful to some as a kind of an introductory reading on the ontology of...

What is the definition and implications of 4D space? By implications I mean if it existed how will it redefine what we know about physics and reality up to now. (Applications, possibilities, etc)

Hello everyone! I got into a debate with a friend about a month back and this question has been racing through my head ever since. Does Math necessarily reflect what's real? He asserted that Math can give you results far-off from what's real. He illustrated his claim like this: Suppose you...

Equations or reality... Hello all, I am new to physics forum and very stupidly I don't have a background or formal education in science. I have one simple question: Time dilation, length contraction, curvature of space-time, are they all mathematically deducable through equations or can...

Is Lorentz factor reality true according to the laws of physics?? Hi According to the laws of physics, the speed of light is independent of the speed of its source. In the example whereby there are two observers; one in the train moving at high velocity u relative to the other observer on...

Hi there, I'm thinking of an experimental set-up that incorporates cameras behind a double-slit screen. The cameras will take a picture if a particle goes through the applicable slit. For me to know which slit it goes through, I need to check the camera to see if its taken a picture. For...

Hello, I'm a physics BS and I'm considering pursuing a graduate degree. Ideally I'd like to pursue a PhD in physics, and I'd like a reality check on my chances of admission. What's really putting a damper on things is my mediocre GPA - 2.81 . I'm well aware that this hurts me lots on graduate...

This is not a question - more a topic of discussion; as I am not expecting definitive answers. At the center of black holes we stipulate singularities, now I understand that mathematically a singularity does not make sense; infinite density and zero spatial volume being irreconcilable and an...