Paradox Definition and 1000 Threads

Hi The setup for this conundrum is like the light sphere illustration. Two frames F and F' ------- F' moving ---->+x at v=.8c At the point of colocation of the origens: x=0 and x'=0 t=0,, t'=0 a light burst is emitted . Looking at two points at...

paradox with Newton's E=1/2mv2 ? Looking for clarification... I don't understand why these points of view don't balance. This is non-relativistic. If two objects are traveling towards each other from opposite walls of a room, then the sum of their Kinetic energies relative to the room does...

We covered SR last semester in Modern Physics I and also covered early Quantum Theory and started Modern Quantum Theory. I've been speculating a bit on SR recently since I started reading The Universe and Dr. Einstein a guy at work gave me. If we have the Earth as a stationary reference frame...

Hi there. I was wondering recently about the Fletcher's Paradox, and Peter Lynds' solution - the idea that time can't truly be measured in individual instants. Now, I'm not actually a physicist - just a science fiction writer. But has anyone proposed the alternate solution that motion is an...

If you were spinning on a marry-go-round approaching the speed of light, would you experience time dialation?

how about this: silly idea, but think about it: the square root of 1 = {+1,-1} and we all know: t'=t/(1-(v/c)^1/2) in essance, t' must simultaneously have values of {+t',-t'} for all velocities not equal to zero and approaching c. this means that for a relativistic frame of...

An integral paradox ?? let be \int_{0}^{\infty}xdx \int_{0}^{\infty}ydy changing to polar coordinates we get that the double integral above shoudl be 2\int_{0}^{\infty}r^{3}dr althoguh they are all divergent , is this true can we ALWAYS make a change of variable to polar...

Maupertuis' principle states in symplectic formulation that the integral of the tautological 1-form is extremal among its integrals on other phase space curves on the given level set of the Hamiltonian, connecting the same starting end ending fiber. Specifically, for closed phase trajectories...

WHat is the present status about the black hole information paradox? Is there some consensus? Could someone recommend good recent papers discussing the current views? Thanks! Patrick

Ok so, supposedly you have two twins in [seperate] spaceships, one approaches the speed of light going away from his twin, then decelerates until going the same high speed but opposite direction, decelerates again to stop next to his twin buddy. The twin that did not move (relative to the very...

Hello to all, I am currently studying computer graphics and I have came up with the following problem. Consider that we have three coordinate systems, let's say CSA1, CSA2 and CSA3 that have the same origin and differ by a rotation. That is to CSA2 connects to CSA1 by R12 and CSA3 to CSA1 by...

hi folks, this is my first post..and here i would like to present a solution to a paradox posed by feynman in the 2nd volume of his lectures (17-4)...for those of you who wish to see the problem here's the link http://varatek.com/scott/feynman_problems.html it's the last problem in that page...

We use the following formulas for the Lorentztransformation: x’ = [ x / sqrt(1-v**2/c**2)] - [vt / sqrt(1-v**2/c**2)] (1) and t’ = - [ (vx)/c**2 / sqrt(1-v**2/c**2)] + [ t / sqrt(1-v**2/c**2)] (2) The twin paradox reads as follows. Gea and Stella are identical twins. Stella...

We know that the twin paradox is not a paradox since one of the twins accelerate and time passes more slowly for him relative to his twin on earth. My question is why can't we apply the same reasoning for length contraction? If one of the twin A measures the lengths of sticks in the reference...

Is action at a distance possible as envisaged by the EPR Paradox?

Homework Statement Two twins, Bill and Ben are 30.0 years old and they leave Earth for a distant planet 12.0 light years away. The twins depart at the same time on Earth, and travel in different space ships. Bill travels at 0.93c, while Ben travels at 0.70c. What is the difference between...

I'm still trying to understand time dilation, the twin paradox, and the effect of acceleration. Yes, I've read the twin paradox FAQ, but it only gets me so far. Here's a hypo I came up with. I've tried to simplify it by (a) making the observers symmetrical and (b) eliminating the...

I've been wracking my brain for days trying to comprehend everything that deals with the twin paradox. I have a vague understanding of relativity and its effects, but am massively confused by most of the explanations given on this forum and other places. I think perhaps it extends from my lack...

Thanks to the post by studiot, I can update my discussion with the calculations. Here's the problem: "Suppose that a flexible 4-ft rope starts with 3 ft of its length arranged in a heap right at the edge of a high horizontal table, with the remaining foot hanging (at rest) off the table...

I'm no physicist, but I read that the speed of light is constant from all observers (regardless of relative speed) and in doing a thought experiment I encountered a problem. Here is the situation: John shoots a laser at you. You turn and run away at near the speed of light, but you look back to...

So i try and try to understand why physics should suggest a quantum entanglement of wigner friend and the observed system, because instantaneous measurement makes a collapse in the system, there should be no question when the wave function is determined. Suppose we consider two equations...

Using Einstein's train thought experiment, suppose a train is accellerating exponetially so that the engine remains forever ahead of a beam of light without it ever reaching the speed of light. V = c[ 1 - e^(-t)] for the train The light would approach the engine but never quite reach it...

Homework Statement The conjecture implies the eigenstate of the observer and observed given by alpha and beta. The problem i am reaching at the end, is whether the well-known Wigners Friend Paradox is answerable by describing the observer and the observed, and then a second observer in terms...

I wrote a response in a thread entitled "What is the single most important thing for life to exist in the universe?" . I thought about it some more and I am wondering if this paradox is scientifically sound or is it just crazy philosophers taking physics and making into voodoo science. I hope...

I'm kind of a noob who's posted a question or two here before to settle arguments and such. Please don't kill me if this has been covered before. I was reading some stuff about space travel trying to get some creative ideas for a sci/fi book idea I had. Nothing serious and really nothing to...

I'm really confused! How can time be relative and speed of light absolute? If you were moving a long with speed, whilst someone else was stationary would you not measure light to be slower??

Hi all, apologies if this has been posted a million times before... I'm trying to explain the twin paradox without getting involved with length contraction. One way to think of it is Twin A remains at rest on Earth then twin B goes off at 4c/5 to Alpha centauri 4 light years away, then...

In the following, "G" stands for "gamma". Clocks O and O' coincide when they mutually read zero. POV is that of K'. Prove: When O' reads T'>0, the coincident K clock reads more than T'. Proof: When O' reads T', O reads T'/G and O' coincides with K clock at x=GvT'. That clock reads...

Homework Statement Anne and Joe are twins, happily living in an inertial frame. On their 20th birthday Joe decides to take a rocket. (a) According to Anne the rocket moves with constant speed v = \frac{3c}{5}. For 6 months it moves away from Earth and then returns in time for Anne's 21st...

Hi! I was just reading about drift speed and I read that the speed is about 10^-4m/s. It then struck me that if electricity is carried by electrons, then in a given circuit, how is the light bulb lighting up so quickly when according to my calculations the time taken to travel 0.5 metres for...

If time stops at the speed of light, how does light travel throught space and time? Example: The light from a star 12 light years away travels throught space and takes 12 years to get to earth. But in those 12 years the time on the star has stoped. Same goes for the light that is leaving...

Hi "If you cycle up a hill and then back down with no net change in elevation, it seems as if your slower uphill speed and faster downhill speed should offset each other. But they don't. Your average speed is less than it would have been had you cycled the same distance on a level road...

I`ve thought about a special sort of twin paradox. I know the usual explanation of the twin paradox but give me please the answer to this special case: Imagine: A static universe (non-expanding) with a closed geometry and a circumference of one lightyear. The twins start their journey in...

Hi everybody! :) can anyone help me with this idea: in the twin paradox, a twin that travels at speed of light in space should be younger than the one that remains on earth. But why can it be other way? Can we say that the twin on the Earth is traveling at speed of light compared to the twin in...

Sorry, I know there are tons of threads about this, but I've been though them all and couldn't answer this satisfactorily myself. You know how it goes. You have 2 twins, A and B, who are magically the same age exactly. They start at the same point in space, each in their own spaceship. They...

In a few places I have read things along the line of this: I am getting confused, because some people say this experiment has resolved the paradox and some people think its still a paradox. How exactly has the twin paradox "been verified experimentally" from the HK experiment?

If the fixed stars/galaxies did not exist, would there be a twin paradox?

Dear forum, when I first read about special relativity I came up with this paradox. I went to the teacher who gave me the booklet but he couldn't answer my question. I'm quite confident that this forum is the place to answer my question: Does time goes slower or faster inside the...

I cannot conceive of a complete path which the "away" twin can follow, relative to the "home" twin, that does not involve significant acceleration. A straight line from home to star then back home in reverse, a centrifugal circle from home (0 degrees) to star (180 degrees) to home (360...

In this story we will have three inertia frames. Frame Fi where both twins start together and at rest with respect to each other. Frame FL moving at a speed v in the negative x direction and Frame FR moving at a speed v in the positive x direction. Both twins zero their watches and start...

I have thought about it and I have found to be confused about something, regarding the twin paradox. As I know it, the twin paradox (set up to emphasize my confusion) is as follows: Two spaceships floating in space pointing away from each other, let's say A and B. When B accelerates and...

Hi all, I've been recently digging into SR in my attempts to better understand electromagnetics. One thing that has been giving me trouble is the force transformation laws, which seem to give rise to some pretty gnarly paradoxes, one of which I've listed here: Consider two objects, where...

Hi, I can see that this topic has been much discussed, but I haven't seen a thread on it with the particular spin I want to give it (just the journey out from Earth). I understand the traditional view of the twin paradox (I think!): Two twins a and b are on Earth and each has a clock. The...

Suppose A travels in a spaceship and B is on earth. At the time of launch they both synchronise their clocks. When 30 secs have passed by in A's clock he reads the time in B's clock to be 40 secs.But when 30 secs have passed in B's clock A's clock shows 40 seconds. Isn't this a contradiction to...

There's discussion on the 'necktie paradox' on this blog, where I'm a regular visitor. I don't agree with the perspectives of those who have responded on that blog. In the wikipedia, The necktie paradox states that each stands to either win or lose an expensive tie, each at 50%...

Is more choice better? Ten years ago the answer seemed obvious: Yes. Now the conventional wisdom is the opposite: lots of choice makes people less likely to choose anything, and less happy when they do choose. In the The Paradox of Choice, Psychologist Barry Schwartz discusses the phenomena...

My query is this. In the twin paradox let's assume that one twin Barbara keeps on moving at a relative speed of "c" away from the stationary Earth twin Alex. If I were to be able to be at both Barbara's rocket and the Earth at the same instant ( meaning I could travel through space...

Ok, so I have been looking at Zeno's Paradox and it occurred to me that it could possibly be applied in physics. The way i worked it out is like so: If an object A is traveling at half the speed of light is given a head start in a race vs an object B that is traveling at exactly the speed...

The following thought experiment describes the energy gain of a system that defies a classical explanation. In this experiment we assume no friction and all velocities are at sub-relativistic speeds, hence, Newtonian mechanics applies and Galilean transformation is adequate. Suppose we...

The "False Twin Paradox" I have no problems with the resolution of the classical 'Twin Paradox', but the following "False Twin Paradox" does have me puzzled. (If it was discussed and explained elsewhere, please just point me there.) Instead of the usual accelerating twin at the turnaround...