Relativity

what is it?

Einstein's general relativity says that all the planets and our earth actually travel in a "straight line" within a curved space-time. Put another way....GR can show that the earth is not orbiting the sun, rather the earth is travelling a straight path and space/time is wrapped/curved around the sun. So gravity = space-time curvature. What are some good non-mathematical ways to conceptualize "space/time" curvature around an large "mass/energy" like the sun? (other than the bowling ball and trampoline analogy that I keep running into when googling the subject) Thanks, Eon.

hey i can't decide whether the answer to quesion 39.3 should be the same as 39.2 (b) or © i gather its © because from the pions view (in the pions inertial reference frame), the time elapsed is 2.6x10^-8 s , and so it would be (.85c)(2.6x10^-8) = 6.6m

Dear Fellow Science Researchers, After much thought and research I have come up with an idea that might lead to the invention of time travel. Allow me to begin by explaining how I believe your speed relative to the speed of light changes the way you move through time. I believe that anything that is moving slower than the speed of light is moving forward through time. Anything that is moving at the speed of light is completely frozen in time. Anything moving faster than the speed of light is moving backwards in time. I do not know how anyone will develop a way to move faster than light. That is not my specific category of research. I hope another scientist w…

just checkin that my mind is working in the right way.... i would say passeenger B measures: A: 39.2 m B: 91.9 m do peoples agree with me? -Sarah

I know when something is accelerated it will be moving slower. and I know when something is going faster than the speed of light - in theory - time would go backwards. so when something IS going the speed of light, does time stop, or just move very slowly? thanks.

I have theory about how a wormhole can be made very easily. And that is.. If I where to strike a match and allow a beam of light to pass through it, I bet the beam of light would pass through quicker than if no flame was present. How much faster would it be? Using that example, the difference would be very minut.. (extremely!) Here's my equation. How can we explain an enviroment in which only space exists. We can imagine as space to be objective. If space equals "O" as "Objective" and if we were to disrupt "O" with an entity equaling "E" (an example of an entity can be that of a flame of a match) where the entity is the disruption equal to friction, th…

hi i can't quite get my head around how this works... or well the way this book does it anyways.... the observer on the rod reads the time of the clock to be 5:(L/(gamma*v)) and yes i agree with this but then the book calucaltes the length of the rod (from the point of view of another observer situated on the clock) by using the time seen by the first observer (who is situated on the rod) that is the observer on the clock calcuates the length of the rod by doing this: length of rod = v * L/(gamma*v) but this is uses the value of the clock as seen by the observer on the rod. but wouldnt the oberver on the clock see a different time to the one the obse…

what is this "b-theory of time?"

Time and space seem to be very abstract. What are they (Pls provide clear definitions, thx!)? Do they share the same basic definitions that we use in our everyday life? Why are they so important in physics? In which area are they useful? How is the theory of relativity useful? Questions, questions, questions.

I havwe a simple question. I tried to search on the forum but it gave to many results so I decided to ask the question: General relativity tell that gravity slowdown time and that is proven by the GPS. Does gravity have an effect on length (contraction or expansion) ??? Thank you for your responses

I've searched the forum incase such a question has been asked before, but I've come up empty. It seems like such a simple and obvious problem that science must have surely found an answer long ago, but I can't find that answer anywhere. Ok, in simple terms.. Relativity states that as objects move, they relatively experience a slowing of time. Upon reaching the speed of light, time relatively stops. Therefore, photons, going at the speed of light, don't experience time. A proof of this is that photons don't age. (sorry, no ref. for this) As far as I know, the above two statements are true and accepted. Here's my issue: c is usually rounded off to…

not sure what to do with this information there's a math and physics blog in french kept by somebody named Fabien Besnard. it seems nice. has some links to recreational mathematics and he is currently talking about the Einstein Centenary conference they had last week in Paris. SFN has some posters who read French (maybe live in France or Quebec, not sure) so might like to check out this blog http://math-et-physique.over-blog.com/ Here is a specific article (the most recent) http://math-et-physique.over-blog.com/article-620261-6.html where Fabien was talking about HOLOGRAPHIC GRAVITY and he referred to this paper (in English) by Thanu Padmanabhan …

For awhile I've felt I understood the basic principles of special relativity, but now that someone is prodding me with all sorts of hypotheticals I find that I really don't understand it all that well. Does special relativity imply that there are multiple "present realities" in the universe? In other words, can two people in two different inertial frames ever agree on what the exact present is? Is there a freeze-frame snapshot of the universe on which all observers would agree? Also, why do physicists use the term "time frame"? It seems deceptive, because although two observers may be in a different "time frame" they can still interact with one another. This impl…

I'm trying to get my head around something in S/GR. Say we have a very large train that contains a smaller train with station inside it. (imagine a model train inside a full sized train) Next inside that 2nd model train set is an even smaller 3rd model train set. Inside this 3rd smaller model train set we have yet another 4th model train set, and so on until we have 10,000 trains travelling with in each other. (like Russian nesting dolls (matryoshka)) Luckily, the first train (alpha train) is very large and is several hundred parsecs long. Anyway, the journey of the first train begins. The alpha train takes off from the alpha station at the speed o…

Is there a difference between the measurement of time and time itself? I was discussing relativity with someone and he noted that only the measurement of time is relative, not time itself. Is there a difference?

Hey im new to this forum, my 1st post anyways just wanted to say dont anyone wonder why there is no real equation to time, like the equations speed=distance/time does not really explain it does it because weight and other veribles such as gravity affects its dont no1 wonder why no1 is smart enough to give a real explination.

I have no idea where this post belongs, but here goes. If a car was travelling at the speed of light, and it turned on its headlights, would light project in front of the car?

I have a new theory about how the entire timeline of the existence of the universe happens almost instantly. Everything from the beginning to the end of the universe happens so quickly that time itself is not measurable without our minds. Our lives are part of the timeline that has been slowed down by our brains. If there were no intelligent brains to slow down the speed of time, everything would seem to happen instantly. Think about the fact that you never waited billions of years to be born. Time itself is change. When the slightest movement of an object occurs, this is a frame of time. The detection of time of our brains creates our reality, in something that…

So i was thinking, i know depeding on the point of view, time will go faster/slow down - and such. example: if you are on earth, and you go in a spaceship and travel the speed of light (assuming you could) towards a star. Your POV is different than that of Earth. Well, what about a POV that can see the star, spaceship, and earth? What does it loook like to them? Do they see it how it "actually is" Object S going c, towards star, away from earth - with no time slowing down for the spaceship?

Choose two objects lets say a train and the station. There is a set distance between them until it accelerates. If the train could approach(accelerate to near) the speed of light it would measure a shorter journey. I call this space variation. But how can you say that the distance between the train and the station in the begining isn't an absolute? Every reference that stayed behind or was at the station waiting would say the train had an absolute space to travel through. As Einstein said Relativity is a thoroughly bad name for the theory. He considered calling it invariance theory!

I have a quick question about the curvature of space-time equation, well two questions. 1. What is "k" on the right hand side of the equation (the equation I am referring to is the curvature tensor equals eight pi multiplied by "k" multiplied by the stress energy tensor). 2. What is the stress energy tensor? I know the second question is really an uber-simpleton one, but it's been on my mind for a while now...

OK.... Two Spaceships Head out of the solar system... They position themselves exactly 1 million km apart and then accelerate, in the same direction, to a velocity of 1000 km/s. They maintain this velocity until they leave the galaxy (Yes I know this would take a long time). Once out of the galaxy they both coast at this velocity for the duration of my question. So the situation we have is this: 2 ships coasting at 1000 km/s (we'll say relative to the last star they passed while leaving the galaxy) parallel to eachother at a distance from eachother of 1 million km. Oh and they are in intergalactic space (as inertial as it gets). They each have bright …

Even tho Einsteins theory E=MC2 is mathematical in nature I have noticed Philosophy is not. I refer to the philosophical word relativist. I love relativity and all it encompasses but, is not mathematics a language in itself? Therefore if this is so why isn't the word/relavatist a word that creates a language? Philosophy in itself is a language in it's own right. The structure is logic which is a language,language which needs no explaining and reason plus some structure with language. In comparison if you will it also leads to mathematical method of reaching a conclusion wheter it is words or numbers. I am not attacking this part of science or Philosophy but both are e…

Is this thought experiment valid or workable? IF we visualize our galaxy in a very large Galaxy CONTAINER. Is it possible that our galaxy (in the container) is travelling at the speed of light? IF observed from the reference frame of a second galaxy moving opposite to ours? Within our galaxy container, all solar systems including ours behave normally. This is a question about the scalability of a reference frame Is this thought experiment valid? Or have I confused something or many things...lol? Thanks,