A paradox is a logically self-contradictory statement or a statement that runs contrary to one's expectation. It is a statement that, despite apparently valid reasoning from true premises, leads to a seemingly self-contradictory or a logically unacceptable conclusion. A paradox usually involves contradictory-yet-interrelated elements that exist simultaneously and persist over time.In logic, many paradoxes exist which are known to be invalid arguments, but which are nevertheless valuable in promoting critical thinking, while other paradoxes have revealed errors in definitions which were assumed to be rigorous, and have caused axioms of mathematics and logic to be re-examined. One example is Russell's paradox, which questions whether a "list of all lists that do not contain themselves" would include itself, and showed that attempts to found set theory on the identification of sets with properties or predicates were flawed. Others, such as Curry's paradox, cannot be easily resolved by making foundational changes in a logical system.Examples outside logic include the ship of Theseus from philosophy, a paradox which questions whether a ship repaired over time by replacing each and all of its wooden parts, one at a time, would remain the same ship. Paradoxes can also take the form of images or other media. For example, M.C. Escher featured perspective-based paradoxes in many of his drawings, with walls that are regarded as floors from other points of view, and staircases that appear to climb endlessly.In common usage, the word "paradox" often refers to statements that are ironic or unexpected, such as "the paradox that standing is more tiring than walking".
(not a paradox nowadays, but it was an issue for years)
https://en.m.wikipedia.org/wiki/Gibbs_paradox
It's not a question about a formula. I don't understand the motivation in physics to claim Gibbs mixing "paradox", the discontinuity point. What bothers the physicist to ask for a continuous...
Hello all.
Recently this twin paradox variant occurred to me, and I can't wrap my head around it:
Alice and Bob are in the same (roughly inertial, for our purposes) reference frame, separated by a sideral distance. Let's say Alice is on Earth and Bob on Pluto.
They synchronize their clocks at...
Hi
Which of these understandings is correct ?
A stationary particle separates into 2 particles A & B
Is it that :
(a) One can independently measure accurately to the desired accuracy the momentum of A and the position of B and thus obtain both position AND momentum of either particle thus...
In the Heisenberg's uncertainty principle
##
\triangle x \triangle p \geqslant \frac{\hbar}{2}
##
what happens when the uncertainty in position becomes very small is that the uncertainty in momentum becomes very large. But what happens when the spread of the uncertainty in momentum becomes...
I’m sure the resolution is something to the effect of “we can only apply special relativity in flat spacetime” but I’m hoping someone can explain in more detail.
Disclaimer: I don’t know general relativity.
So in a positively curved universe, if you keep traveling (let us neglect expansion)...
Let's imagine that there are two people who has the same biological age. One is inside a spaceship, currently crossing a Quasar(A) in a constant velocity near the speed of light toward the Earth and the other is on Earth(B). In this situation, what will happen when A moves to the Earth and meets...
So I stumbled upon this paradox and was wondering what cosmologists had to say about it. For the most part, I take an instrumental view of science. Of course, I accept all scientific histories and truisms as rational touchstone, though I also think we can never be too precocious about the fate...
The Twin Paradox implies that the universe as a whole is a special frame of motion according to "Relativity Simply Explained" by Martin Gardner. I want to be sure than I haven't misunderstood something. I don't find the explanation completely clear. If the universe as a whole is a special and...
A and B 1 lyr apart and sync watches, C moving at .5 C, when at B, C sync watch with B, what time does A and C's watch show when meet. (I was told answer already here but could not find).
Here I consider the twin paradox for two observers moving in the Schwarzschild spacetime, i.e., the spacetime where one has one radially symmetric non-rotating star, leading to the invariant line element (written in the usual Schwarzschild coordinates)
$$\mathrm{d} s^2=\left (1-\frac{R}{r}...
Bob is standing on Earth and Alice is on a distant planet at a constant distance from Earth. Their watches are already synchronized in the following sense: Suppose Alice's planet is a light-year away from Earth. Bob emits a light signal to Alice at time t = 0 according to Bob's watch. When Alice...
As a layman I also have conceptual difficulties with the twin paradox. It would allow me to move on if some one could quickly answer the rather obvious question: would there be any time dilation if the Earth was removed entirely from the thought experiment so that the twins are in a symmetrical...
So as we know momentum has a formula p=mv right ?
But why we can't write it as p=m+v ?
The real question is why we multiply both mass and velocity quantity
And not add them ?
According to Bell's theorem quantum mechanics is not local.How can we combine it with Special Relativity which is local and gives us another successful theory?
In Taylor and Wheeler, problem 6-5 "Detonator Paradox," a T-shaped plunger is not long enough to strike a detonator inside a U-shaped container. However, if the T-shaped plunger is moving relativistically, then in the reference frame of the T, the U shape is shorter and so the T is able to...
Hello I have been trying to understand the twin paradox (without math) but I’m still trying to grasp the idea. I have seen and read enough tutorials to know that acceleration is not needed for the twin paradox to be solved. For anyone who doesn’t know the twin paradox without acceleration...
Let's take a pair of particles A and B that are in a quantum entanglement state, and shoot them in different directions. Along the way, one of them will pass in the famous screen of the two slits, say B. According to the known experiment, if we put a detector in one of the slits, we will lose...
Hello there,
I had another similar post, where asking for proof for Hilbert’s Hotel.
After rethinking this topic, I want to show you a new example. It tries to show why that the sentence, every guest moves into the next room, hides the fact, that we don’t understand what will happen in this...
It is a long message indeed but there is one doubt I want to ask, As from the above video the time measured by the person which is outside the Frame of reference let's say t' depends on the position and time measured by the person within the Frame of reference. But how do we know that whose...
In this version of the twin paradox one twin, A, is located on earth, and the other twin, B, is located on a distant planet, which is at a fixed location in A's frame of reference.
At the beginning time t = 0 the twins are stationary and their clocks are synchronized at 0.
A gets on a rocket...
Assuming we have an infinite plane capacitor,where the upper plate is charged positively and the bottom layer is charged negatively. Now we know the field outside the capacitor is zero so we can't tell if the positive charge is on the upper plate or the lower plate.
But, if we place it inside...
Let u, v be column vectors n x 1 and M a m x n matrix over a field K. If M*u= M*v, then (M^-1)*M*u=(M^-1)*M*v, thus, I*u=I*v. Hence u=v. But that shouldn't be the case. What is wrong in my reasoning?
Thank you.
For instance let's take that a neutron star mass is so high that the gravitational force is more than the coulumb force. If this happens then then the electrons will go down and alpha particle will be left . This is not observed in the star so how will the particle stay normal
By the way I am...
I'm considering a dynamical model of the scenario of a disease spreading across the population, modelling the number of cases, and there's a mathematical puzzle which I'd like to solve.
It's kinda different from the S-I-R model, and its also a crude model.
First, we consider two numbers, NT...
The paradox I am referring to is that which can be resolved by considering the fact that ##\sum_{k=0}^\infty1/2^k=1##. However, before one can travel half of the distance to be travelled, he has to travel half of that half, and half of that half ... Moreover, to say that one can travel by halves...
Ok, I hope someone can help me see how to sort this out.
Alice has a full-frame (no rolling shutter) video camera that records exactly 30 frames per second. It's mounted to a telescope looking far out into space.
Bob is out there in space with a digital clock that reads out to the millisecond...
A question to Vsauce's famous video about the Banach-Tarski paradox at 10:09:
Can you really construct the hyper-webster like that?
If you choose the order like that, you'll never get any words containing other letters than "A". Shouldn't you choose an order like A, ... , Z, AA, ..., AZ...
Suppose there is a beam balanced on a fulcrum at its center of mass. One observer at rest with respect to the beam sees two lightning bolts strike the ends of the beam simultaneously, such that there is no net rotation of the beam. However, a moving inertial observer sees one bolt strike one...
Gibbs introduced the N! to then make S extensive. He then attributed the N! to the particles being indistinguishable. How does the N! signify the indistinguishability?
Summary: Does the three polarizer paradox work with other materials?
Alright, so this is going to sound like a dumb question, but if you were to do the three polarizer experiment but replace the polarizers with a another material, could the different material produce a similar effect to that...
Sorry if this is a stupid question but I couldn't find an answer anywhere. According to 2 scientific papers, the neutron star PSR J1748-2446ad has a rotation rate of 716Hz, which equates to a linear surface speed of 0.24c. What if this star was originally rotating, let's say, 5 times (or more)...
Does any parallel universe theory include the concept that in at least one of the parallel universes, there is no option for there being parallel universes? If so, how could that unique universe not kill the entire theory?
I was reading this book on mechanics by derek raine and came up on something called friction paraddox.
Suppose a block is is moving with constant speed and the external force is balanced by friction. We know friction causes heat dissipation and the external force supplies some energy so as to...
(I swore to myself I would never ask a relativity question again...oh well)
I don't know why I can't find anything about this in a search so I guess I'll just have to ask. Is a twin that takes off to Mars to stay, younger than a stay at home twin or is it ambiguous? I would think that this...
I feel a little guilty writing this post because I'm sure there are people here who are tired of answering questions about the twin paradox, hence the FAQ post on the subject, but there's something which is still nagging me. First I have a question about the FAQ post itself. Toward the bottom of...
Hi! Does anyone think Banach-Tarski's paradox needs reworking? I first came across it in a video by Vsauce. I've been told that things might be reworked as to avoid the paradox, just as set theory was fixed so as to avoid Russell's paradox. How to make sense of a smallest unit of space is what...
Hello, I was wondering if anyone could set up and solve a classic train in a tunnel paradox from special relativity with unique values for multiple observers including time space diagrams. Thanks
This question is more a question I'd ask in a chat rather than formally on paper/forum.
If we take the free electron model, the electrons are considered as non interacting. It is essentially a 1 particle problem where the potential is constant through space. The electrons are not perturbed at...
Bohr declared it the duality paradox. It works. But a paradox in science is an unresolved problem. Are we any closer to resolving that problem 100 years after Bohr's declaration, or has the physics community just grown numb to it?
This quote from Wikipedia says that temperatures in the Thermosphere can reach 2,500 C during the daytime but "despite the high temperature, an observer or object will experience cold temperatures".
"The highly diluted gas in this layer can reach 2,500 °C (4,530 °F) during the day. Despite the...
Thanks. This made a lot of things clear to me.
But there's one last thing that I want to check: Twins paradox is not a paradox, right?
It says that one twin goes to space at near light speed and the other stays back on Earth. Then the one in space returns like f.eg. after 30 years. The twin...
The Faraday paradox is a very curious example in the topic of relative motion.
An experiment demonstrating the curious results is shown in the video below:
This has made me curious about the linear version of the Faraday paradox.
A conductor placed atop a magnet, both at rest in one scenario...
I'm trying to solve this problem but I get a different answer depending on which observer I solve it for.
For the observer in the cloud, the parallel light has traveled 2.294cs, but this is only 0.23cs in front of the ship. 0.23 cs is only 0.086cs in the perspective of the ship due to length...
Hello, I could some help. I've reached some sort of paradox. Ultimately I'm trying to calculate the number of pixels per inch, given a pixel size of 5177 nm and extended at a distance of .7inch (.0178 meters)
(A) (60 arcsecs * 0.0178 meters)/206268 = 5177nm pixel per arcmin
(B) 5177 * 60 =...
Say there is a circular fence that has a diameter of 10 meters, and a rocket ship that is normally 20 meters goes very quickly so that its relativistic length is 1m from the position of an observer standing at rest with relation to the fence.
The rocket ship starts to go in a circle inside the...
Suppose an observer (O) sees a traveler (T1) pass by at time t=0, moving a speed 3c/5. Five years later (according to O), T1 returns. If we assume that T1 traveled at 3c/5 for half the journey and instantaneously reversed direction, returning at the same speed, we can calculate that T1 aged only...
If they could solve the information loss paradox in black hole
https://en.wikipedia.org/wiki/Black_hole_information_paradox
What other related problems it could solve in Beyond Standard Models or unsolved quantum questions, etc.?
If the LHC could no longer detect new particles, could beyond...