Contraction Definition and 689 Threads

Hey, sorry if this is a stupid question but I'm getting really confused... If I am standing on the Earth and watch a spaceship moving past at say 0.8*c from left to right, I will observe the spaceship to contract in its direction of motion. If a person on the spaceship shines a torch also from...

Hello, Just one quick question. What happens to the molecular structure of an object if it moves close to the speed of light? Does the high speed affect the atoms, protons, neutrons, electrons, molecular structures? Does the density/thickness of the object increase? Or do the protons and...

I made my own problem and tried to answer it to see if I understand relativity well. Can you please let me know if I got the answers right? A spaceship moving at .866c compared to a pair of stars. The stars are located at points A and B which appear to be 2 light seconds apart from an...

if length contraction only applies in the direction of motion, then what happens if there is an angle to the direction of motion that's not perpendicular?

A meter stick moves past you at great speed. Its motion relative to you is parallel to its long axis. If you measure the length of the moving meter stick to be 1.00 ft (1ft=.3048 m), for example by comparing it to a one-foot ruler that is at rest relative to you, at what speed is the meter...

Length contraction equation determining v. what am i doing wrong? OK, L=L*(1-v2/c2)1/2 (to the power of 1/2) L=.75m L*=1.0m now i need to find v and for the life of me i always end up with a value greater then c which is obviously impossible. ill simplify to v=...

Does the equation for Lorentz contraction stay exactly the same when quantifying the 'mass increase factor' at relativistic speeds? Further, when one moves at close to light speeds, the view of the surrounding universe seen from the ship is distorted into a circular window. Would the...

it's a typical homework problem I suppose, a meter stick traveling at v=.8c at an angle of 60 degrees to v as seen in the stick's reference frame. I solved it out and got .6m, which is incidentaly the same answer I got for if it were traveling parallel to v. is that, you know, how that works?

When I accelerate my object it shrinks lengthwise: 1.nose moves back closer to tail OR 2.tail moves forward closer to nose OR 3.both ends move closer to middle OR 4.none of the above ?

How do you find relativistic length contraction?

Let's make it simple and suppose you have a very, very, perfectly sturdy record or something, and a record player that can spin it at enough RPMs to give the edge of the disk a speed that is a significant fraction of the speed of light. Since length shortens along the direction of motion...

Could someone please, briefy explain length contraction under general relativity?? Is it possibly for the universe to contract around a spaceship so that the distances between stars become only inches.. and thus it becomes possible to reach stars lightyears away in very little time? THe...

Why do muscle fibres need T-tubules for the action potential to go down to stimulate the sarcoplasmic reticulum to release calcium ions? Why couldn't it just travel along the sarcomere? Thanks. :-)

Hi all, Can someone tell me what to expect and how to calculate the length contraction when two bodies move towards each other, rather than away? The particular question I'm stuck on is this: A garage is 5m long, a car approaches it at 0.6c. What is the length of the garage according...

In the SR section of my book there is a question like this. An astronout is traveling at .9C. The spacecraft has a proper legth of 100m. a)what is the length observed by observer? I get this as I divide 100 by gamma which is about 2.29 b)Astronouts view is also effected by the time it...

Hello I am doing a project on the Lorentz Fitzgerald contraction and would like to know if the original research papers are available on the internet. Thanks!

If a passing spaceship sends a beam from the back to the front in their time of L/c andthen immediately the beam is reflected from front to back, can an stationary observer using proper time determine the length contraction formula? I don't see how to set this up. Thanks for any help.

I'm having trouble understanding how length contracts while time dilates when the 2 equations in the lorentz transformation dealing with these are nearly identical (which makes me think that length and time should transform in the same way). Thanks in advance.

Does anyone know how in LQG they avoid the contradiction of a smallest unit of quantized space and Lorentz contraction?

Muons have a "proper lifetime" = 2.2 micro seconds ("proper lifetime" = lifetime of a muon which is at rest). These Muons are created in the upper atmosphere at a height of 4700m above the Earth's surface. So, a muon traveling at a speed of 0.99c can travel only a distance of 653.4 m if you do...

Hi, I was wondering why some plastics seem to shrink when heat is applied? Does the plastic expand when it is colder? Is it some how due to the molecular bonds in the material rather then the ionic bonds in something like a metal that expands when heated? Thanks Derek Mohammed

how can you explain that a rocket ship traveling at 99.999% of c will see a beam of light pass by it at c with respect to the space ship? what exactly is the definition of time dilation and length contraction and what formula's are used to explain the phenomenon(sp?) thanks :smile:

Just an issue I want to be absolutely clear about. Scenario, WE propell a rod of iron with a dimensions of 100 meters *1 meters through space with the 100 meter length perpedicular to the direction of velocity. So the rod is traveling width edge forward. ( perpedicular to direction)...

Those who teach special relativity consider it a very important exercise to have students decide how to measure the length of a rapidly moving object. That's religious indoctrination and a wrongheaded approach to physics. The theoretical process that physicists talk about to measure the length...

Here's another one for ya'll. A spacecraft antenna is at an angle of 10 degrees relative to the axis of the spacecraft . If the spacecraft moves away from the Earth at a speed of .70c, what is the angle of the antenna as seen from earth?

Is length contraction relative or absolute?? This is from the book "Speakable and unspeakable in quantum mechanics" by J.S. Bell. Three small spaceships, A, B, and , drift freely in a region of space remote from other matter, without rotation and without relative motion, with B and C...

Hello all. I've recently had something of an epiphany regarding relativity. One of those moments when things become clear and it all makes sense. However, having not actually performed any of the experiments which may or may not support the whole thing, I have a question. Is there evidence...

I'm looking through One Two Three...Infinity by George Gamow. After having explained length contraction with the example of two ships passing in space who each view the other as contracted he comments in a footnote: "Of course this is all a theoretical picture. Actually if two rocket ships...

Question "Length Contraction" Hello, I just finished reading special theory of relativity written by Albert Einstein himself. Even though I understand the book is only written to convey general idea it still left me with a lot of question. Einstein said that any event that occurs in one...

Hey, I am new to this site, I'm not entirely sure where i should post this question but can anyone here help? I need to know Einsteins assumption of the speed of light as a constant by referring to length contraction, mass and time dilation and how it affects people traveeling in space at high...

Suppose an electron has a small radius and we look at its radius and mass from the point of view of special relativity. Let's use the idea of (mass x length) = constant. No quantization. Is the contraction to zero radius at c a problem? If so then we can guess how to stop it. One way...

If length contraction was quantized, then a particle of a given radius could have a constant radius for many observers moving at different speeds. Could such a particle be used to formulate a quantum field theory?

My question is rather simple: Are there experiments where they have measured length contractions?

In Einstein's SR the velocity of the light (c) is same in every referent frame. Let us for instance assume we don't know its exact value and try to estimate it. The relative distance suffers contractions depending on the velocity of the frame like this: L=L_0\sqrt{1-\frac{V^2}{c^2}} where L0...

suppose you had a planet with a train going all the way around the circumference. The train is a complete loop so you just have an endless train. now speed the train up to near c. Because of length contration would the train begin to squeeze the planet?

If I was traveling close to the speed of light and passed a hotdog outside, the hotdog would appear smaller to me compared to the hotdogs I remember eating on Earth correct? If I was traveling close to the speed of light with a hotdog in my hand and held it right in front of my pants, as I...

I don't recall seeing this derivation anywhere but its probably somewhere in the relativity literature since most things are. A poster at sci.physics.relativity posted what he thought was proof that the Lorentz contraction doesn't exist. See the Fig. 1 in Lorentz Contraction - Version 2 --...

would some be able to give me an example that shows some evidence of length contraction? i have looked at the muons example, but it seem to be dependent on the time dilation effect, rather than being evidence of length contraction. thanks for any help.:) much appreciated. btw, feel...

This is a thread about physics law. Physical laws are supposed to be invariant under choice of metric units. The meter and the second, for instance, are arbitrary choices. If we had come upt with other units of measurements, the physical laws would be the same. But as to how far can this...