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2answers
67 views

Twin paradox in special relativity: length contraction

Can the concept of twin paradox be applied to length contraction as well? meaning that the twin which is in spaceship will have its meter rod "actually" contracted while he will see his brother's ...
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1answer
77 views

How is time dilation consistent between both observer?

There is a special variant of time dilation paradox bugs me. Imagine there are 2 small spaceships moving toward each other in constant speed. Each ship has an observer on-board. According to both ...
0
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1answer
25 views

Synchronization of clocks

I have read the book "Introduction to special relativity " by Robert Resnick In the book I have found that "If the distance between the clocks is L, one observer will see the other clock lag his by ...
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2answers
121 views

Meaning and logic of Einstein's train thought experiment

This seems to be a recurrent topic but I wasn't able to find any satisfactory discussion about this tought experiment. I will quote the original story from Einstein's and put my doubts inside: Up ...
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1answer
79 views

Black holes shouldn't really exist? [duplicate]

General relativity states that for an observer sufficiently far from the gravitational field of a blackhole, the space time geodesic nearr the event horizon is so long that we should never observe an ...
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1answer
45 views

Geiger counter in the Schrodinger's cat experiment

Inside the Schrodinger's cat's box, the moment the radiation is detected by the counter, doesn't this mean the system already has a fixed eigenstate (a collapsed wave function, or is decoherent, ...
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2answers
49 views

Observer in the double slit experiment with photons

In the double slit experiment with photons, the interacting observer is an instrument, detector… If you replace the detector with a piece of metal with the same mass as the mass of the detector, the ...
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0answers
26 views

Value of $E_x$ through an $X-\textrm{boost}$

Suppose I'm standing at the (0,0,0) point of a coordinate system and I see an electric field where $E_x=f(t,x,y,z)=\sin(x\cdot y\cdot z\cdot t)$ and at time $t_0=0$ I start moving on the x-axis at ...
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1answer
63 views

how long will take for an astronal travel in near lightspeed in his point of view

I always had a question about relativity. Suppose an astronaut in orbit Saturn just must reach earth fast as possible. Your ship can travel at any speed between 0 and the speed of light. the distance ...
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2answers
49 views

Regarding relativity of simultaneity

I recently started studying Special Relativity an my book discusses the following: Say I have synchronized two separated clocks in a reference frame S, if then an observer in another reference frame ...
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1answer
30 views

Special Relativity and Composition Law for Velocities with respect to an observer watching two objects moving away from a central point

So I understand that special relativity is all about the frame of reference and there is a lot to do with time dilation and how space-time is warped at velocities near $c$. So my question is what ...
2
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2answers
91 views

Relative relativity,

Suppose a box A is moving relative to a Box B then by time dilation equation, if I take 1 sec passed for an observer in A then for an observer in B will be little longer. Now if I suppose, that the ...
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5answers
243 views

Rapid (ac/de)celeration in relativity does what to inertial clocks?

EDIT (to clarify my question): I think some of the answers here are accounting for light travel time and telling me what I'd actually see on Earth's clock, so I've edited my first paragraph to ...
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3answers
86 views

When calc. time elapsed for an inertial reference frame during travel between two points, are length contraction and time dilation taken into account? [closed]

When calculating the amount of time elapsed for an inertial reference frame over the course of its travel at constant velocity between two points, are the effects of both length contraction and time ...
1
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1answer
54 views

Relativity of simultaneity: two light sources

A. Suppose a moving train. The train has two wheels(front and back) and each wheel is connected to light source inside the train. The light source is triggered(light is emitted) when train passes ...
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votes
2answers
135 views

Lorentz contraction explanation correct? [closed]

I was having a heated SE chat debate with someone re relativity. One of us believes the explanation above is correct, while the other believes it is not. Who is correct, and, if the explanation is ...
1
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1answer
58 views

Does travelling towards something at relativistic speed cause it to appear to speed up?

If one were to travel towards a giant TV floating in space, at a fraction of the speed of light, would a video playing on the TV appear to play faster? I'm guessing the answer is no. From what I ...
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1answer
54 views

Twin Paradox From Neutral observers perspective

Suppose two planets A & B, with B moving away from A at velocity v. A spaceship departs from A in the direction of B at velocity v (putting it in the same inertial frame as B), and remains that ...
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0answers
45 views

Twin Paradox Variation using 2 rockets [duplicate]

Instead of a twin on earth and a twin on a rocket, what would happen if they were both on separate rockets facing opposite directions. One fires off at 0.7c and the the other fires off at 0.2c. Then ...
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0answers
35 views

Relativity of simultaneity: light source inside and outside

(Orange are light sources and red are observers) There is a train, which is moving right. In each side, there is a light source, which emits light when the train passes certain point on a track. And ...
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3answers
86 views

How time dilation happens by velocity?

i got many explanation and proving that relative velocity causes time dilation. Einstein's moving light experiment proves it. but that is a clock works with light detector. as detecting the light gets ...
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votes
1answer
94 views

Time slows down as you approach the speed of light, travelers observe speeds faster than light travel? [closed]

If I was on a spaceship traveling almost at the speed of light, my time would slow down relative to the time for a stationary external observer. My question is, since we measure distances between ...
-1
votes
1answer
153 views

Time dilation confusion? [duplicate]

If I understand the theory correctly, time dilation causes a moving clock to tick slower than a stationary clock. If clock A is moving relative to clock B, then clock A ticks slower. However, ...
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4answers
120 views

Is there anything we are aware of that can't be slowed by time dilation?

While thinking about the ambitions of this post: Can radioactivity be slowed through time dilation? I was asking myself, is there even anything that is dependent on time and can't be slowed through ...
0
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2answers
41 views

What is the relationship between the flow rate of time and gravitational field?

I have heard, qualitatively, about the fact that time's rate of flow slows when the gravitational field is "strong". Here I am looking for some more rigorous descriptions of this phenomenon. My first ...
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3answers
84 views

Time in spaceships near the speed of light

I know that the time on a moving object moves slowly compared to a stationery one, but if someone on a spaceship that moves at V=0.5c and a person is driving it. Will he notice that the clock on his ...
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5answers
3k views

Can someone conceptually explain time dilation?

Can someone intuitively explain how physically time dilation happens? Please don't explain about the invariant speed of light and the mathematical background, I am familiar with that. I just can't ...
1
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0answers
36 views

Relativistic Particles [closed]

The question: An electron is moving at $0.6c$ in the lab frame. For an observer moving at $0.8c$ in the same direction as the electron's motion, what is the electron's kinetic energy (in MeV)? ...
1
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0answers
68 views

Light at the Speed of Light [duplicate]

Since light particles travel at the speed of light, we know it's possible for something to travel at that speed. However, since all things are relative, and if time does stop at the speed of light, ...
1
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4answers
209 views

Explanation for a much simpler version of the twin paradox?

I have seen the classical twin paradox before. It uses a twin stationary on Earth and the other traveling away and back. I have seen many contradictory solutions for it, some use general relativity, ...
2
votes
1answer
70 views

How do I know which observer is running the time faster or slower

Ok, I'm not a physicist, so I don't know if my question is silly (probably yes), but there is something in special relativity that I can't understand and I would really like it to be clarified. If ...
0
votes
1answer
48 views

Could we recognise if time was running at a different rate for one species than another? I.e a human and an ant

My question is quite simple if time ran at a different speed for smaller creatures, how would we be able to observe this or confirm by experiment?
1
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1answer
30 views

Does matter stacks up as it approaches Black hole?

When something approaches Black hole it'll experience time dilation with respect to a frame away from the black hole. So to an observer away from the hole the object would seem to slow down until ...
1
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1answer
61 views

Why do i see more steam coming out from the vessel containing water after i turned off the stove? [duplicate]

It is a little observation i did when i was boiling the water. what i observe is that when i turned off the stove on which the water was boiling i could see more steam coming out from it than the ...
1
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1answer
53 views

Understanding the basic concepts of quantum mechanics using a model [duplicate]

I'm not an expert and I don't know if already exists something like the following model, but I wrote a simple (mental) model to understand the basic concepts of quantum mechanics. I want to know if ...
0
votes
2answers
50 views

Double slit with observer?

https://www.youtube.com/watch?v=Xmq_FJd1oUQ Apologize if this is a dumb question, I'm just a kid trying to make sense of something that I'm new to. It shows the wave interference when you send a ...
1
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1answer
106 views

Does the property of being “virtual” for a particle depend on the observer?

I've read at several places that a static magnetic (and electric for that matter) field can be thought of as made by virtual photons, at least that's what I understood. Now, in Special Relativity we ...
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3answers
103 views

Double slit experiment without observer

If we used an instrument to record the double slit experiment but never looked at the footage so to speak, what would the mathematics show us?
0
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2answers
80 views

For a giving metric in GR, how do we learn which observer the metric refer to?

For example, I have been told the Schwarzschild observer is far away from blackhole and events,(namely, I think, the observer is static at infinity of the coordinate.) And the second example,the ...
1
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1answer
117 views

Can you shine a laser on an object that has fallen into a black hole? [duplicate]

I've been having a small back and forth on another website about the nature of objects that fall into black holes. I know that they never reach the event horizon from the perspective of a distant ...
1
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1answer
45 views

Can we see ourselves slower due to time relativity?

Please bear with me because I'm noob at physics. Numbers don't have to be calculated, these are just examples, I'm just asking conceptual stuff. Just double check: Objects traveling at $0.99c$ in ...
0
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2answers
86 views

Age of universe?

Well relativity teaches us that time interval between two events is a frame dependent quantity, then how can we say that our universe is 13.8 billion years old? Should it not depend on who is asking ...
2
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2answers
45 views

The observer detail of double slit experiment

I have been searching internet for a while and I couldn't find any detailed information about the observer type in double slit experiment of electrons. For example is the observer a camera or ...
3
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1answer
94 views

Special Relativity in water

If there are 2 observers in water moving relative to each other as well as to water, they measure different speeds of light. So does time dilation occur for them? (since Time dilation is based on ...
1
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0answers
39 views

Biological concept behind time dilation [duplicate]

What is the exact mechanism which makes aging process slow for persons travelling at higher velocity relatively. How does our body cells responds to gravity and undergo aging?
1
vote
1answer
74 views

Operational Definition of Reference Frame in General Relativity

Most treatments of GR begin with the assumption that spacetime is a pseudo-Riemannian manifold (or, sometimes, that it is a more general manifold). But this entails quite a few tacit assumptions about ...
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2answers
53 views

Do all moving object appear contracted?

In the derivation of Lorentz contraction my prof considered a rod moving away from you with speed $v$. In this case the rod appears shrunk by a factor gamma. But now let's consider a rod moving ...
0
votes
1answer
54 views

Metric of an accelerated reference frame (without gravitation)

If we look at a flat Minkowski space-time (without any gravitation) an choose an accelerated frame of reference, what happens to the metric tensor is it still in Minkowski coordinates or will he be ...
0
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0answers
52 views

Twin paradox in special relativity [duplicate]

The Twin Paradox involves 2 observers, usually twins. Let them be named A and B. A remains at rest in the same reference frame as Earth while B is in a separate reference frame moving at velocity v, ...
0
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2answers
59 views

Will my mass increase in my perspective while approaching near the speed of light?

Suppose I start my journey by a spaceship accelerate the velocity to 0.7c from Earth. Now the question arises that- Will my mass increase gradually as I'm going to a speed of .7c in my perspective and ...