Twin's paradox confusion,the travelling twin would b younger or the earth bound twin?

Question

the tavelling twin could equall well say that he was at rest in spaceship and earth was moving away.so according to him the earth bound twin was moving and his earth bound brother should b younger than he is.so according to earth bound twin he was older and according to the one in spaceship he was older.so who is youger and who is older???
(i wont accept confusing answers such as both will b younger for each other.)

Answer 1

The traveling twin would be younger due to time contraction at speeds near the speed of light. The twin's speed would be relative to the earthbound one. The earthbound one would measure time in his timeframe - not contracted. The travelling one would measure it in his contracted time frame. That's why when the travelling twin came back he'd be younger. It's a difficult concept.

Answer 2

The twin that is traveling faster then the other twin will be younger. If you travel at light speed to Polarius and back it time on you will only take it's toll a few minuets, but back on earth decades have passed.

I think your problem needs revision:
You have twins, they grow up and are exactly the same age within seconds ((this is just an example)) when they grow up, one twin decides to become a pilet and the other decides to work in a resteraunt, well the piolet will be traveling all the time in the air at high speeds and the other doesn't go past 70 miles in his life time. Bye the time they're 90 the piolet will be younger then the cheif by 1 day.

See how that works? But gravity also effects time, and the younger brother would be the one in the space shuttle definantly.

Answer 3

The whole point of the paradox is that it depends on your frame of reference. When I don't take the paradox into account though, I generally have the earth as a frame of reference and hence the one on Earth is the younger one.

But, even though you don't want this answer, I'll explain the paradox to you. Picture the situation, and focus your attention on the twin that's on Earth. His brother is speeding away, and since time passes so much slower when he's traveling the speed of light, by the time he gets back, the twin on Earth has only aged one day, and yet the twin on the ship has aged years and years because he was traveling the speed of light. So in theory, with the Earth as a reference point (or the twin on Earth), the one on the ship is older.

But focus on the twin traveling the speed of light, now. Time passes slower for that twin. A single moment can be hours or even days on Earth. He leaves and comes back after a day of traveling, and he's only aged a day, whereas years have passed on Earth. With the space ship twin as a reference point, the Earth twin is older.

That's whole point of the paradox. There is no right answer. It's a paradox.

Answer 4

Dude,

Here is some information for you:

The Twins Paradox: Why Acceleration Is Not Relevant

One of the most baffling and disturbing problems of relativity is the famous thought experiment of the Twins Paradox, in which one of two identical twins leaves Earth in a spaceship on a voyage at relativistic speeds to the nearest star and back. When he returns, he finds that while the trip took him a very short time by his shipboard clocks and he is only a few weeks or months older, many years have passed on Earth, and his identical twin is an old man.

This would seem on the face of it to be a violation of the fundamental principle of relativity, i.e. that motion is relative. If all motion is in fact relative, then why does the twin on earth age and not the one in the spaceship? Why does there seem to be a privileged frame of reference with respect to the passage of time?

It has been argued that the essential asymmetry of the Twins Paradox lies in the fact that the spaceship accelerates, and the Earth does not, and while motion is relative, acceleration is absolute. I intend to show that while this is true, it is only circumstantially relevant to the problem. The true asymmetry of the Twins Paradox, and the one that leads to the age difference of the twins, is the asymmetrical way in which the Lorentz contractions affect the different reference frames. (It might also be pointed out that the Twins Paradox is a Special Relativity problem, and acceleration is only addressed in General Relativity.)

Let us conduct another thought experiment, then, in which the symmetry is preserved, and then I shall attempt to show how the Twin Paradox is a special case of this experiment. Imagine two relativistic passenger trains, the Solar Express and the Proxima Bullet, running on a parallel set of tracks between Alpha Centauri and Earth. Let's say each one is about a light-minute long. These two trains are scheduled to leave their respective stations at around the same time, pass each other about halfway between the two stars, and then arrive more or less simultaneously. Of course, simultaneity is a pretty much meaningless concept in relativity, but exactly when the trains leave and arrive is not important to this problem. We are only interested in the part of the trip, somewhere along the line, when the two trains pass each other.

We don't really know which one has accelerated more than the other, and in any case, it doesn't matter. Let's assume that both have accelerated exactly the same amount since leaving their stations, and so there is complete symmetry between the two trains with respect to speed, length, distance travelled so far, and rate of acceleration. As a result, each engineer will have fairly similar observations of the passage of the other train by him.

From the perspective of the Solar Express, the Bullet's length has contracted to a fraction of the Express' length. The engineer of the Solar Express, then, will see the locomotive of the Proxima Bullet flash by his own locomotive (event A) only seconds before the caboose streaks by (event B). It will, however, take almost a whole minute for the Bullet to reach the caboose of the Express (event C), since the Express is still as long as it ever was, and it will of course take only seconds for the entire length of the Bullet to pass by the caboose (call the moment the cabooses pass event D).

Meanwhile, from the perspective of the Bullet, the Express' length has contracted to a fraction of the Bullet's length. The engineer of the Proxima Bullet, then, will see the locomotive of the Solar Express flash by his own locomotive (event A) only seconds before the caboose streaks by (event C). It will, however, take almost a whole minute for the Express to reach the caboose of the Bullet (event B), since the Bullet is still as long as it ever was, and it will of course take only seconds for the entire length of the Express to pass by the caboose (event D).

Note that while the overall experiences of both engineers are similar, they differ quite dramatically on their measurements of specific intervals. For example, the Bullet engineer will report a much shorter period elapsed between events A and B than the Express engineer will, while the Express engineer will similarly report a shorter elapsed time between A and C than the Bullet engineer will.

Okay, now, here's where the Twins Paradox maps onto our train problem. Say the locomotive of the Solar Express is called Earth, and the caboose is nicknamed Alpha Centauri. In the Twin's paradox, we're only concerned with the time it takes for the Bullet locomotive to go from the Earth to the Alpha Centauri (events A and C), which is of course shorter for the Bullet than it is for the Express. We don't even think about the time it takes for the Bullet's caboose to reach Earth, A-B interval, which is longer for the Bullet than for the Express! The basic asymmetry of the Twins Paradox lies in the landmarks used to define the trip, and not in the acceleration of one or the other reference frames. Indeed, the Twins Paradox would still have the same results if it were the entire Galaxy that accelerated and the spaceship remained still, since the time interval which is of interest remains A-C and not A-B.

Answer 5

Isn't it amkkoig how mghhgd up sikjhung can be azd sjil be umderstgndjble?

The difference between the person who was at rest and remained at rest, and the person who took off in whatever direction is that the person who took off accelerated. This is important for the following reason.

The universe is not really as it seems. Not only does this funky thing with time and length occure, but in reality, "present" is subjective.

If you and I were standing on a street corner near a clock, and when the clock says 3:00, we both see one car run a light and hit another, we can both be sure the accident occured at 3:00, but if I was on the street corner, you were speeding at 60% of the speed of light wearing your brand new Rolex, which one hour before, by your point of view, you syncronized with the clock, and we both saw the accident happen, we would NOT agree on what time it occured.

But if either of us knew a little bit of math and physics, we could figure out what time the accident appear to occure to the other person. To conceptualize this process, physicists use what's called Minkowski spacetime.

For examples of this see the Wikipedia article on twin paradoxes using the link below.


Because time is no longer something we can agree upon, we are in different reference frames. But I've remained stationary and you haven't. YOU'RE the one who switched reference frames. A rough analogy is kind of like when you go from one country to another and have to switch currency. Maybe you're from a country where $1 is worth $100 and youyou're rich, but then you go to a country where $1 is worth their equivalence of ten cents, now you're poor. They use a formula to figure out how much you will have.

So anyway when you accelerate you switch reference frames and all of you information from one reference frame has to be converted to the new one, while the stationary person never did switch reference frames.

I know it's confusing but you have to keep in mind that the universe doesn't always work how it initially appears to, just like the Earth from the surface, at first glance, may appear as flat. It's only when one gets thinking about it a little more that they see that it isn't.

Answer 6

The twin whose velocity undergoes a radical change will be the younger relative to the twin whose velocity underwent the least relative change. In other words, the twin who got on the rocket ship and went almost as fast as the speed of light, then turned and came back to the earth and stopped or at least greatly decelerated to earth's speed underwent the most radical change in velocity. The twin whose velocity remained relatively constant, or stayed on the earth in the same space-time frame of reference, would have had time elapse normally. The twin who went for the trip would have had relativistic time slow down in his/her frame of reference. By the measure of the earthbound twin time elapsed during the trip was (just an example) say 10 years, for the travelling twin he/she would say time elapsed during the trip was 10 minutes. So, the earthbound twin had sat and waited 10 years, aging in the interval, for his/her brother/sister's trip. The traveler would only have waited 10 minutes for the trip to finish and aged 10 minutes.

Answer 7

C-man is right. The difference between the twins is that the one in the spaceship has accelerated, decelerated, accelerated again and decelerated for the return trip. So he's the one who returns younger. This has been tested experimentally with two identical atomic clocks. One stayed at home and the other sent on a trip in a passenger jet. The one on the plane returned a few microseconds younger.

Answer 8

Both age progress, in other words, both get older. The earth-bound twin would get older by our frame of reference, let's say 1 year for 1 year of experimentation. If the traveling twin traveled for a year and returned, he or she would be nearly one year older, but not quite. He or she would be probably a few seconds younger than the earth-bound twin. Got it?

Answer 9

Firstly, its time dilation and length contraction... not the other way around. Time dilation can be depicted by the Lorentz factor... the equations: dt= (gamma)dt(naught) and g= 1/ sqrt (1-v^2/c^2) where v is the relative speed and c is the speed of light. Come up with a hypothetical situation and input those values into the Lorentz equation and you will see that the twin on earth will have aged slightly more.

Answer 10

usually the twin paradox has the twin in the spaceship traveling. But if you're saying that the twin on earth is traveling, then he is younger. Who ever travels is the youngest once they meet again.

Allthough I mean that they are the youngest as in they won't die first, although their life may last a lot longer, so it depends on how you look at it.