Can someone explain the Theory of Relativity in simplified terms?

Question

Can someone explain the Theory of Relativity in simplified terms?

Answer 1

The speed of light is the only constant in the universe and cannot be exceeded or reached through normal space. Space and time are not absolute. Space can be distorted, and time can proceed faster or slower depending on whether you're moving fast or whether you're in a gravity field. These effects are minute unless the gravity is really strong (like in and around a black hole) or the speed is really fast (about 20% of the speed of light). But, the minute effects are important. For example, GPS relies on the difference in time that a satelite recieves a signal to calculate its location on earth. The difference in the how fast time proceeds between the surface of the earth and the orbit of GPS satelites is large enough that if we didn't account for relativity, the best approximation of location we could make is within about 100 yards instead of the inches we can get with relativity.







Edit:

No. Each beam would still be moving at the speed of light. When they passed each other, they would pass at the speed of light. This is because the spacetime frames are different. It's a hard concept to grasp but it's been tested thousands of times and is true.

Answer 2

To start the complications: there is the Special Theory and then there's the General Theory of Relativity. The later deals with accelerating reference frames, which we don't need.



The Special Theory of Relativity really states that when there is no acceleration (e.g. a nice train ride between stations) the laws of physics behave independently of where you are. So one can deduce that if you are moving the speed of light remains the same to someone who is not. The only way this can happen is if time changes.



(The first question is why? The only answer is: well that's the way the universe works and every time we do an experiment it shows that Einstein is right, and our common sense if wrong.)



With this simple fact: the speed of light is constant for all observers (moving with constant velocity), we can deduce that mass is just a form of energy. If you have a lot of mass, you have a lot of energy; if you have a little mass, you have a little energy. That means that mass and energy are proportional to each other, m ~ E. The constant between the relationship is simply the speed of light squared, so we get E = mc^2.



(Again why? Well that's just the way the universe works).



Since c^2 is quite a large number we see that even minute amounts of matter hold (or require) huge amounts of energy.

Answer 3

Einstein's theory states that an object in motion creates its own timeframe. In short, a person walking past someone on a park bench is actually in a seperate universe, based on the passage of time. However, the difference in the time shift is so small, it is impossible to measure. However, as an object approaches the speed of light, the time shift becomes observable. One elegant proof of Einstein's theory was a subatomic particle which formed in outer space. It's halflife was too short for it to be detected on the earth's surface. However, these particles were being detected. The answer was that traveling so close to the speed of light caused them to decay much slower in our own time frame. Einstein imagined he was actually sitting on a photon of light and wondered what the universe would look like. Everyone knew that the speed of light was completely independant of the speed of the observer. This means that two cars traveling the speed of light would each see the other vehicle pull away from them at the speed of light. The only way this was possible was that time was not constant, and depended on the speed of the object. This is the very heart of Einstein's theory. E=MC^2 was a result of this insight and is basically what made it possible for engineers like Oppenheimer to precisely calculate the energy of atomic bombs. In modern times, the equation is used to design nucleur reactors.

Answer 4

This Site Might Help You.



RE:

Can someone explain the Theory of Relativity in simplified terms?

I know that e=mc^2 (energy equals mass times the speed of light squared) but I'm not really sure what it all means. Please don't just tell me what wikipedia says, because I've been there and I don't really get it. I'm not a Physicist, nor have I taken any physics classes.



I...

Answer 5

Can you imagine how the universe is right now? Well maybe so and maybe not. But surely it is a certain way right now, right? Well maybe yes and maybe no. What?! Well maybe its not a certain way "right now"! Maybe its "relative" not "absolute"! That's the amazing thing.



Einstein realized that the idea of "right now" was only an idea and when you tried to make an experiment to see how things "really are" "right now" "everywhere" that you just can't do it. You can see how things "really are" "right here". But not "out there". You are forced to do a calculation. Why?



Well Einstein realized that no one can "see" the universe except from some one place where they are standing. He realized that you can't actually see things you can only see light, and it takes time for light to move to get to you so you can't really see how things "are" only how they "were" a while ago.



But how long ago? Well you have to see what you see first. Then you measure how far away things are. Then you use a formula that is called Distance=Rate*Time to find out the time the light started out.



But to do that calculation you need to know the "speed of light" (the rate that light travels... how fast it goes.) If it goes really fast then what you see happened just a short time ago because if it goes fast then it won't take long for the light to get to you.



But if it goes really slow then it will take a long time to get to you and by the time it does you will say: "Well sure I can see it but that light is soooo old that I know what I see happened a looong time ago. It took that light eons to reach me!"



So how do you know how fast light goes? Well usually things go at different speeds depending how fast you go! For example if you are in a boat looking at your mother she isn't moving but if your sister is outside, on the shore, watching her in the boat she moves as fast as the boat does! You will say "She is not moving". Your sister will say "Yes she is". So who is right? The answer is that the both you and she are both right! The speed of your mother "relative" to you is zero and "relative" to your sister its as fast as the boat! There is no one right "absolute" answer. Her speed is "relative to the observer".



Basically scientists thought we were like a boat on a lake and that light was like waves in the water. They were trying to find out how fast our boat was moving in the water relative to the waves so they could calculate how fast the light would go relative to us. Once they knew what speed light went, then they could tell when things really happened "out there" based on how long the light coming from them took to get to us.



The funny thing was that whenever they tried to measure the speed of the earth-boat in the light water ... well... they got zero over and over. No motion! No matter how it seemed we were going around the sun! How could we be stopped always! How could light only have one speed.



Its like your sister is on the shore saying your mother, who is in the boat with you, is going as fast as a boat. Then you look at your mom, who is in the boat with you and she is going away from you as fast as a boat! That's crazy!



No matter which way the earth boat was going if you looked at a light wave it seemed it was traveling at the same speed. This was really weird because if you were in a fast boat the wave seemed to be getting ahead of you at the same speed as a slow one. Scientists were very confused.



(Also there was a man working on electricity and magnets and he had these calculations that said light should only have one speed because he thought light was a type of electric and magnetic wave and his calculations always calculated the same number for the speed of light!)



Well Einstein said "Fine, ok, everyone is saying that light only has one speed relative to everyone, it seems that no matter how you move your standing still relative to the water that light travels in. I know its crazy (actually he said "apparently contradictory" but.. well he was Einstein... you can't expect him to uses words like crazy) So he said: "I know it's crazy but what happens if I just think that way anyway!" And he did.



And then HE did some calculations and that's when the fun started. He found out for example that if you think that crazy, excuse me... that "apparently contradictory" way.... then things that everyone thought were true just couldn't be.



What things? Well like there is such a thing as how far away the sun is. Or that there is such a thing as the way things are right now!



He found out two main things: If the speed of light is the same for different people moving different ways then they must see time and distances differently. He found out that time and space were "relative" just like the speed of the boat was. The speed of light is not relative! And the only way that can be true is if time and space themselves are relative! Relative means it depends on how fast you are going when you measure it.



Here is some of the weird things that happened when he thought that way for a while....



Did you know that the sun is only four inches away! YES ITS TRUE! If you travel really fast towards the sun the distance shrinks! But for me it will still be a long way away! You see the distance isn't a certain number! It depends on how you are moving when you measure it. It is "relative" to you! It is not absolute! There is no absolute answer only a relative one! Wow! Get in a space ship boat and head for the sun really fast and just when you pass earth you say... "Wow its only four inches to the sun!" But poor me on the ground, I say "Your crazy its ninety three million miles" How can we both be right? Its like you in the boat and your sister on the shore... It's relative! If light's speed is not relative then time and space must be!



Also he found out that "time was relative" meaning that if your mom left in a spaceship and went fast enough outward and back that she might arrive back here and BE YOUNGER THAN YOU!



WOW! What a theory! Time is not what we thought. Space is not what we thought. Other things he found out was that E=MC^2 but that is another story.



So is it weird or what! He was an incredible genius and you know what. He was a nice man too and he didn't stop there!



He also found out that it just might be true that if you go up in any direction from the earth far enough you may end up back here! That's right. The earth may be to the right of you, to the left of you, up, down, in front of you and in back, and all other ways too. He found that space may be ROUND!!!!



Just like if you were an ant at the north pole and you walked far enough you would end up back at the pole. But if you walked to your right far enough, or went backward same thing. Amazing no?



Anyway, how do you tell time? Answer: You look at your watch! See you already know there is a connection between light and time. Now you just have to really think about that connection and you'll know relativity. Good luck with your study and I hope you try to really understand it and not just believe everybody that its that way. You have to thing very, very carefully. Good luck!

Answer 6

E=mc² - Energy equals mass times the speed of light squared.

An outstanding feature of Special Relativity is its mass-energy relation, which is expressed in the well-known formula: E=mc².

Einstein derived this relation in an attempt to reconcile Maxwell's electromagnetic theory with the conservation of energy and momentum. Maxwell said that light carries a momentum, which is to say that a wave carries an amount of energy. Due to the principle of conservation of momentum, if a body emits energy in the form of radiation, the body loses an equivalent amount of mass that is given by E/c². This describes the relation between energy and mass.



According to the conservation principle, in a closed system the sum of mass and its energy equivalent is always the same. The mass-energy relation tells us that any change in the energy level of an object necessarily involves a change in the object's mass and vice-versa. The most dramatic consequences of this law are observed in nature, for example in nuclear fission and fusion processes, in which stars like the Sun emit energy and lose mass. The same law also applies to the forces set free in the detonation of an atomic bomb.

Einstein was not directly involved in the creation of the atomic bomb, as some people assume. His credits are rather being the one who provided the theoretical framework. In 1939, Einstein and several other physicists wrote a letter to President Franklin D. Roosevelt, pointing out the possibility of making an atomic bomb and the peril that the German government was embarking on such a course. The letter, signed only by Einstein, helped lending urgency to efforts in the creation of the atomic bomb, but Einstein himself played no role in the work and knew nothing about it at the time.



Can anything travel faster than light?



No. In Relativity, c puts an absolute limit to speed at which any object can travel, hence, nothing, no particle, no rocket, no space vehicle can go at faster-than-light (=superluminal) speeds. However, there are some cases where things appear to move at superluminal speeds, such as in the following examples: 1. Consider two spaceships moving each at 0.6c in opposite directions. For a stationary observer, the distance between both ships grows at faster-than-light speed. The same is true for distant galaxies that drift apart in opposite directions of the sky. 2. Another example: Consider pointing a very strong laser on the moon so that it projects a dot on the moon's service and then moving the laser rapidly towards Earth, so that it points on the floor in front of you. If you accomplish this in less than one second, the laser dot obviously travelled at superluminal speed, seeing that the average distance between the Earth and the Moon is 384,403 km.



So c is the limit and the answer to the question.



What is gravity?



Gravity is the force that causes objects on Earth to fall down and stars and planets to attract each other. Isaac Newton quantified the gravitational force: F = mass1 * mass2 / distance². Gravity is a very weak force when compared with the other fundamental forces. The electrical repulsion between two electrons, for example, is some 10^40 times stronger than their gravitational attraction. Nevertheless, gravity is the dominant force on the large scales of interest in astronomy. Einstein describes gravitation not as a force, but as a consequence of the curvature of spacetime. This means that gravity can be explained in terms of geometry, rather than as interacting forces. The General Relativity model of gravitation is largely compatible with Newton, except that it accounts for certain phenomena such as the bending of light rays correctly, and is therefore more accurate than Newton's formula. According to General Relativity, matter tells space how to curve, while the curvature of space tells matter how to move. The carrier particle of the gravitational force is the graviton.

Answer 7

You are correct: this is all very complicated stuff, but it is easy to grasp the fundamentals. Basically, it all stems from two premises:



1. The speed of light is constant. An observer standing still measures the exact same speed as an observer who is moving 75% of the speed of light measures.

This holds true even if the source of light is moving too.



2. The laws of physics are the same in all frames of reference. So moving observers get the same answers as stationary ones.



From these two simple principles, all kinds of crazy, non-intuitive predictions follow, the notion of "absolute space and time" are thrown out, and ultimately ending up with E = mc² the mass-energy equivalence. So far, all of the predictions have been measured, and found to be very accurate.



In order for the frames of reference to be consistent, you have time dilation, Lorentz contraction, and other weird things happen.



Special Relativity did not deal with gravity, General Relativity does, and predicted that light would be bent by gravitational masses. This was measured in 1919 in the famous eclipse that sealed Einstein's reputation as a genius.



Hope this helps to "shine some light" :-)

Answer 8

There is in fact not one Theory of Relativity but two. In 1905 Einstein, who was then a humble patent clerk in Switzerland, published four landmark papers on various physical phenomena, such as the photoelectric effect and Brownian motion, and including the Special Theory of Relativity. It was known from James Clerk Maxwell's equations that light travels with a fixed speed, and prior to Einstein's paper it was taken to mean that the fixed speed in question, about 300,000 kilometres per second, was with respect to "the aether", an omnipresent medium for the transmission of electromagnetic waves with contradictory physical properties which would indicate an absolute fixed reference for motion throughout the universe. The problem was, as Michelson and Morley discovered to their considerable surprise, that the aether was completely undetectable and the speed of light was unchanging NO MATTER WHAT THE SPEED OF THE OBSERVER or which direction the observer moved in.



Einstein did away with the nonsensical and contradictory luminiferous aether by stating that the speed of light was fixed for each OBSERVER. This was very surprising and implied, for the sake of consistency in measurement, that time and space, rather than the seed of light, were changing and variable for various observers rather than the speed of light.



In 1915, he released the General Theory of Relativity which, based on the observation that it was impossible to distinguish the effects of a gravitational field and the effects of acceleration, showed that the way that gravity worked was the distortion of space-time by gravitational fields, implying the existence of black holes for example.

Answer 9

What you're asking us to do is an exceedingly difficult task. Actually, though, just about everybody in the know agrees that Stephen Hawking did a great job of explaining it in the book

"A Brief History of Time". That's probably your best source. It's difficult to understand, but far, far more difficult to explain plainly.

Answer 10

Trixie -



This is a very complex subject. I guess the easiest way to paraphrase it is to state that there is no such thing as an absolute position or speed or momentum in the universe. That means that when you ask questions about these things, you have to ask "compared to what?" This results in some pretty non-intuitive observations.



For example, in Special Relativity, we learn that the speed of light is a constant, regardless of the speed of the source or the observer. This means that if you measure the speed of a light beam from a star that is receding from you at .99 x the speed of light, that light will still pass you at exactly the speed of light. The same is true if you are departing or approaching a star - that way noone can tell whether you are moving or the star is moving, because there is no fixed or favored frame of reference. This in turn does things like affecting the passage of time in frames of reference that are moving at high speeds relative to each other, etc.



In General Relativity, the same principle is applied to things like gravity. We find that gravity is not really a force, although it acts like one. It is a warping of space-time (sorry for the buzzwords) in a way that changes what we think of as straight-line motion through space into a curved path oriented toward objects with mass. The force must be applied to keep us from falling in that direction; the falling is caused by gravity.



There's about a lifetime or so of work wrapped up in these two paragraphs, but it's a synopsis.





ADDED: The speed of each of the two light beams passing each other in opposite directions will still be exactly the same speed of light - regardless of where you are measuring it from. You could not travel on one light beam to measure the other one, because you cannot reach that speed - but you could theoretically reach .99 x that speed in the same direction. If you did, you would measure the speed of the light beam traveling in the opposite direction as exactly the same speed of light - relative to you.



Speed and geometry and time are all relative - not fixed. If you are traveling past me at a high speed, I will measure your length as shorter, your time as longer, and your mass as higher than you will. Neither of us is wrong. It is how the universe works.



The speed of light from distant stars has been measured very precisely. It is always the same - whether we are on one side of our orbit moving toward the star, or the other side moving away. Whether the star is moving toward or away from us - still the same. We can tell that we are moving toward or away from the star by Doppler shift, but the speed of the light as it passes us is always exactly c. Not terribly intuitive, but if it didn't work that way, the universe would suddenly be a very strange place - so it was a brilliant series of ideas by a brilliant person.

Answer 11

Matter tells space-time how to bend, and space-time tells matter how to move.

That's the simplest way to explain General Relativity. Einstein's theory reconciled Special Relativity and Newton's Law of Universal Gravitation. E=mc^2 is the mass-energy relations, which Einstein also developed, but isn't necessarily funamental to General Relativity. In developing General Relativity, Einstein created the Einstein Field Equations, a set of 10 non-linear, simultaneous partial differential equations that can be combined to form a single tensor equation. These equations are very complex, and many people (myself included) don't really understand what all the numbers "mean". But, for a layman's explanation, the first sentence should suffice.

With regards to the light beams passing each other, that assumption is false, because it's based on Newtonian mechanics. Newtonian mechanics aren't "correct", they're just valid for low velocities. Look up the Lorentz factor for more info. One consequence of General Relativity is that the speed of light is constant in ALL reference frames. If you're on a train travelling 50 mph, and throw a baseball at 100 mph, then to an observer on the ground, the baseball is moving at 150 mph. However, if you're moving at the speed of light, and then throw a baseball, classical mechanics tells up that the ball should be moving at c+100 mph, which is false. However, general relativity tells us that the ball will actually be travelling at a speed less than the speed of light, according to an outside observer. Weird, huh?

Answer 12

Theory Of Relativity For Dummies

Answer 13

The key concept here is the relativity of mass (the 'm' in e=mc^2). As the speed of a matter approaches the speed of light, the mass (or weight, in layman's terms) can change and hence cannot be measued. In other words, it becomes 'relative'. This also led to the first realization that mass can actually be converted into energy at speeds approcaing that of light (eg- the speed of subatomic particles like electrons)



As to the two light beams passing each other, sure, their speed relative to each other is twice the speed of light, but the actual speed is still only 'c'.

Answer 14

Sure thing.



The Theory of Relativity was brought up by Elbert Einstein in 1905. It consists of two theories-the General Theory of Relativity and the Special Theory of Relativity.



According to the General Theory of Relativity, it is impossible to distinguish between gravitational fields and the other force fields in space. The gravitational field or any field of force produces measurable because of the presence of matter in the universe.



The Special Theory of Relativity states that it is impossible to measure or detect the absolute motion of a body through space. However, one can accurately determine its relative motion by using the speed of light as a basis.



The understanding of the of time as the fourth dimension besides length, width, and height (commonly known as the four-dimensional continuum or space time continuum) and the strange effects an object takes on as it approaches the speed of light will also help you understand the Theory of Relativity.



The speed of light remains the same, or constant, no matter what the frame of reference, by the way. The frame of reference is a number or quantity you base something on.

Answer 15

Actually no, they can't. Think of it this way: Newton was a towering genius and original thinker and he missed it. So did Leibniz, Euler, Maxwell and a host of heavyweight thinkers. It took an extra-extraordinary mind, that of Einstein, to discover the Special Theory of Relativity.



I myself am at ease in all the scientific and engineering disciplines, and have taught many of them at the college level. I can do the math and have gotten through a high-level physics course at a very good university, but I have never been able to get my head around relativity. General Relativity is even worse.



Bottom line: if these concepts were understandable by us ordinary mortals, they would have been discovered sooner.

Answer 16

its about relativity literally...if you were going the speed of light relative to the speed on earth you would age less. Time actually slows down as you reach the speed of light. This is vague and can be applied in several other ways. Get the book the Tao of Physics.

Answer 17

if u are really interested in theory of relativity, u must go through all the papers of einstein, rather than asking for simplified form.

Answer 18

Thanks for opening these guys up, Trixie! I knew they understood what I am talking about in the Physics involved in my new innovation in Continuous Reinforcing Systems for building and structure frames!



Drew F; Your first sentence in describing relativity matches the functionings of dual-frames, where one frame is rigid, and the second frame is flexible. You described exactly what happens to these frame systems when they are impacted by an external force. The frame's rigid and pin-connected continuous network is slammed by 120mph winds, and blows apart. The second, continuous tension-primary net-frame "catches" the frame within its stretched limits, acting like a retaining and containing net. My innovation is how to place, locate, and attach a net to the interior side of structure frames, whether the strucure is anchored or free-standing. As building frames, when completed, are heavy, by weight; to develop the applied net, the net's materials/components, had to meet certain criteria, including tighter structural mass (like steel vs. wood/masonry), have at least partial flexure along one of the XYZ axis', be small enough, geometrically and dimensionally to develop non-inhibitive-to-the-rigid-frame location compatability, be as durable and long-lasting as the materials of the rigid-frames, be able to develop a connecting/attaching method that allows for multiple component connectings with a single/isolated anchor/fastener, have higher shear and puncture resistance than the rigid-frame's materials and components, among others. The only object I know of that can meet all of these criteria is the corrosion-resistant, strong, durable, structural-grades of steel continuous and/or dimensionally long flat/planar strappings, now a common manufactured product.

As the functions of the dual-frames matches any forces that might impact on the frame, these frame units become assembled structures of Momentum Equilibrium. By matching the functions/physical actions of the external forces, each force can be addressed, in multiple methods, like strong rigid-materials to match/exceed the strengths of the force(where structure design is currently), retainment of the rigid frame by the flexed stronger net of the rigid frame components to address the twistings, momentums of the structure past the center of gravity (prevents the building falling and progressive collapsings), and with all of the structure's seams addressed, and each of the three-point intersections better connected, prevention of building body dislodgements, roof separations, etc;

Where this applies to e=mc^2, is once the dual-frame structure is assembled, it becomes a singular unit, which can address all forces applied to it, including as the fusilages of spaceships, boats, submarines, and even the automobile. With these hi-tech frames, spaceships can handle faster speeds AND speed accelerations, without breaking apart from internal fusilage frame vibrations, boats and submarines can be higher pressure-resistant and have lighter hulls that can go faster, be stronger, and go deeper in the oceans, and car-bodies can have lower collision damages and higher impact resistances.

As a Building Technician, meaning I have background in Engineering, Architecture, Construction, and Building Safety Design and Assembly Review and Inspection, I primarily show how continuous reinforcing applies to building and structure frames, and my working prototypes are of simple box-frames that the rigid frame components are post/beam and stud in-fill framing typical of wood and light-gauge steel framed houses, sheds, and so on. These are called Open-Space Frames by the Construction Engineers, and are the hardest to reinforce to resist forces of hurricanes, tornados, etc. My protoypes show much improvement in the amount of force it takes to collapse, dislodge, or break apart these box-frames, than any current reinforcing system for these types of frames.

Take a look at the samples on my website and see if you can easily see the improvements that are evident in the photos of a prototype and some drawn/illustrated examples throughout the website. See if you can see the relations to Newton's Momentim Equilibrium and Conservation Theorems, his 2-carts in unison movements illustration, and any applications in Einsteins General Relativity Works, including e=mc^2.