Simultaneity Definition and 298 Threads

Ok folks, this is my first post to this forum and I’m afraid that I might be asking an embarrassingly simple question! I’m reading Einstein’s book on SR and GR and I’ve reached a discussion of simultaneity that involves an observer attempting to decide if lighting strikes that occur ahead and...

This is sort of a long post but I have to explain the following situation in order to ask the question so bare with me. Let's say two people, person A and person B, are on opposite ends of a train moving at a constant velocity and another observer is at rest on the platform outside (most of you...

Watch this video and tell me shouldn't the passenger in the train see both lightning strikes at the same time considering that light speed is perceived as the same speed no matter how fast you travel or where it comes from? Watch both these vids...

I have poured over my old college textbook (Mould) in its description of simultaneity. I came across one sticking point that I don't understand. The proper equation to describe the relative time between two different points is: Eqn 1) t' = gamma (t - Lv/c^2) This equation makes sense...

Hi everyone, I got interested in physics recently and started reading a book called "relativity simply explained " by martin gardener. when i was going through the book i got some doubts in relativity of simultaneity. my problem is described below o>>> ---------------------------<< 0...

recently i read about the embankement-train thought experiement, however i find it diffcult to understand supposer the right end of the platform is A and left B, a train of same length as platform travels from B to A direction. In the reference frame of the platfrom, a observer in the middle M...

confused about this thought. Object A and B are d distance apart, as measured by an object exactly in the middle of them, object C. A and B are moving towards each other at c/2, again measured by C. According to C's frame of reference, all three objects will collide at the exact same moment...

I'm having trouble understanding the simultaneity experiment with Alice on the railroad car, and Bob observing from the ground. If 2 lightning bolts hit the front and back of Alices car at the same time in Bob's frame, it won't be instantaneous in Alices due to simultaneity. My question is...

1. Absolute simultaneity with standard synchronized clocks In an one space dimensions approach we propose the following scenario. At the origin O of the inertial reference frame I we find a clock C0(0) and a source of light S(0). An observer R’ moves with constant speed V in the positive...

i recently posted a question (light and time) someone told me to look into loss of simultanety... according to what i read the speed of light can be judged by someone or things frame of reference.(if I am traveling at .999 the speed of light the light in front of me and coming from behind me...

Homework Statement Two events, A and B, are separated in space. In one frame of reference, event A occurs first and is seen to cause event B. Is it possible to find other frames of reference where event B occurs before event A? If the order of two events does depend upon the frame of...

if an object is made of particles that are interacting via electric and magnetic fields that propagate at the speed of light then does it not follow that a moving object will experience a loss of simultaneity? in other words, it is not necessary to go outside of classical physics to explain...

I'm curious about how people here view Einstein's prescription for determining simultaneity in an inertial frame, and how the extension of that approach to other inertial frames spawns the Lorentz transformation. It seems to me the competing pictures here are that this is an arbitrary way (in...

1. Homework Statement : We have a pole vaulter, and farmer, and a barn. The vaulter is traveling at 0.866c (as measured by the farmer), and carrying a pole that, in his reference frame, is 10 meters long. The barn has an open door at either side, and is 10 meters wide, in the farmer's...

Three enemy spacecraft have been causing trouble in the asteroid belt. They always travel in a line, evenly spaced apart, attempting to chase down local spacecraft to steal their goods. The local asteroid colonists have decided to set a trap to capture these three spacecraft . They'll get...

Revisiting the lesson of the "Relativity of Simultaneity" So, we have the "relativity of simultaneity", which is meant to show us that two relatively moving observers have different notions of the concept of "time", because (as in chapter 9 of Relativity), the person on the moving train will...

The Doppler shift formula relates two proper time intervals measured in I and I' respectovely (tau)=D(tau)' D representing a Doppler factor that depends on the relative speed of I and I'. By definition the events involved in I and I' respectively take place at the same point in space. If the...

Consider please the Lorentz transformation for the time coordinates of the same event t'(E)=g(t(E)-Vx/cc) (1) where g stands for gamma and t(E) and t'(E) for times displayed by clocks synchronized following Einstein's procedure. My question is: with what times displayed by how...

Recently I was reading about tunneling experiments showing faster-than-light tunneling effects, and commentary that it should be impossible for them to be FTL, as this would contradict special relativity. In the context of simultaneity being 'relative' in SR, it would cause the paradox of being...

If the below algebra is correct then a light flash originating from the center of a train with .6c will be observed inside both train and platform reference frames as striking the back in less time. Given : train length= 20ls v = .6c lorentz factor .8 As observed from the platform the...

why we do not observe any “lack of simultaneity” when we substitute sound signals for the light flashes in the “thought experiment” with a train moving past a platform (Einstein's lightning strike-train "thought experiment")? this has troubled me for 5hours now. i don't know whether it is too...

I was wondering does the notion that the universe is expanding uniformly means there is no absolute rest, but there is absolute simultaneity?

i wanted to say relevance but i figured that would be too easy :smile: editing there is something I'm not getting. yes if the speed of light is the same in all intertial frames simultaneity is relative but so what? can someone explain to me how this implies that time and space are relative...

Einstein’s train-carriage example: A train-carriage is moving at a constant velocity v relative to the ground. An observer is stationed on the ground perpendicular to the midpoint of the train at time x relative to the ground’s frame of reference. At this time, lightning strikes the front and...

Simultaneity Let's imagine there is a train moving at the speed of light. When in the middle, two lightning flashes appear on it's left and right. Why is it that it sees the right flash before the left? And if it is moving left to right, why does it see the left before the right? It is to...

Is there any practical reason for calculating simultaneity of distant events? Two events either are causally connected or not, and there is nothing relative about this. If a cause-effect link doesn't exist, does it matter if the events are calculated to be simultaneous from a certain point of...

Hi... I know that this question will be found little bit stupid, but unfortunatly I can't see where I made a mistake. Let's have stick with light sources on both ends. In stick's reference frame the flashes from both sources are simultaneous. In laboratory ref. frame they are not. However...

Hello, First of all, I’d like to tell you that I’m not fluent in English (I think it’s important to say) and that’s a reason why I’m asking my questions here. Sorry for all the mistakes in this text. When I was in my bedroom, looking at the light bulbs of the ceiling, I wondered about the...

I've picked up relativity, again after getting frustrated. I'm new but I need help understanding simultaneity. I tried to read further but it seems to be very important to all of Einstein’s other arguments. So here it goes. In relativity, the special and general theory, P 30 about halfway...

I read the post entitled "Thought experiment in relativity of simultaneity". It's pretty close to my question but not necessarily needed to answer my questions. Situation: On observer (A) is "at rest" and another observer (B) is in a reference frame moving with respect to observer (A)...

Hi Please explain following on simulataneity.. Two far removed relatively at rest observers are on the plane of simultaneity.But if some event occurs in the close vicinity of observer1, he will see it immediately whereas it will take years for oberserver2 to see that event; and vice versa. So...

My text reads thus (the part which is bolded is that which I don't understand, I just reckon that the rest is needed for the context) : This seems very wrong to me. Am I incorrect in saying that Mavis must see the two flashes simultaneously, and also must conclude that they happened at the same...

Is the relativity of simultaneity relative? I've been thinking about this for a while and this is really troublesome... The short question: Why can’t we draw the conclusion that simultaneity is relative only when events involving light/electromagnetic radiation are considered? The...

How do I derive the equation for Simultaneityfrom one of the lorentz transformation. If you can help me with that, please help with time dilation as well. The textbook focused mainly on the mathematically derivation without using the lorentz transformations, and I cannot find any answers...

That is, why did he use signals whose speed is invariant?

I realize this question includes relativity, but I think it is more appropriate here than in that forum? [Tell me if I should cross-post it elsewhere; I'm new to this forum :)] I'm working on a paper based on reading material that doesn't address big bang cosmology directly, but rather...

How can two events happening at the same time and place in one frame of reference happen at a different time and place in another frame of reference? For example: If you are standing at the side of a road and you see a car going at 0.6c and 8 light seconds down the road in both directions...

OK, can someone answer this for me? Let's say we have two spaceships, Ship A and Ship B, traveling toward Earth at v= 0.866c relative to earth. They are at rest relative to each other, not accelerating, and Ship B is at a distance of 5 light years behind Ship A (as observed by them). They...

I'll start with the set up. a b c d e f g h ... <-V a' b' c' d' e' f' g' h' ...' a, b, c, d, and e are all .5 a light second apart. The primed letters are all moving with a velocity of .5c to the left. a, c, and e emit...

I really think I'm not understanding this correctly and I haven't had a chance to think it through, but I'm confused about the issue of simultaneity in special relativity. As I understand it, a simultaneous event happens at exactly the same time in some reference frame. Special relativity...

This question is from an IB exam in may, 2003 and I'm having a little trouble understanding how they got their answer. The question is, Person A is in a carriage that is traveling in a straight line with uniform speed relative to person B who is standing on the platform. Person A is halfway...

Suppose we have two frames (frame 1 and frame 2) which are passing each other infinitesimally close at a relative velocity v with respect to x axes in both frames.. We have two points, a and b, in frame 1 with separation L along the x axis. We have two other points, c and d also in frame 1...

The classic example of demonstrating the relativity of simultaneity uses bolts of lightning striking two places "simultaneously". When you do the same experiment with sound then all observers can determine which event occurred first because sound does not follow the 2nd postulate of SR.

The figure is of a moving frame moving to the right at velocity = 1/3c. On each end of the frame is a mirror (L and R) located at 4(1/3 + 1/3 + 1/3 + 1/3) x (1 second) from the midpoint of the frame. A pulse of light emitted at M (on either the moving or stationary frame) . We define the...

I was listening to Feynman on space-time and he challenged the audience to find a paradox in simultaneity over large distances, or a paradox resulting from knowing what was happening in a region of space outside your light cone...is there one i can't think of? it seems like there shouldn't be an...

Is the relativity theory postulate of simultaneity reasonable? M is half way between light sources A and B. Simultaneous pulses from A and B arrive at M at the same instant a moving observes heading from A to B arrives. Does the moving observer see the lights turn on simultaneous in his...

Is Simultaneity an Illusion? It is if one agrees with Einstein’s theory of special relativity. It is not if one agrees with Alfred North Whitehead’s contention that we do immediately apprehend the simultaneity of spatially separated events. Whitehead’s assertion is based on a desire by...

Hello everyone, I am new to this forum. In oct 2000 I submitted a paper to the European journal of physics on the non relativity of simultaneity. Essentially, the paper didn't deal with the theory of relativity, so much as it did with the issue of simultaneity. The paper was not...