twin paradox?

Question

There is this famous paradox of two twins: one goes off to space in a spaceship at a very high speed and the other twin stays back.
Apparently, when the twin returns to Earth she will be younger than her sis who stayed back in Earth.
How can this be...... the Earth twin will see her sis's time slow down. Similarly, the traveling twim will see her sis in Earth has slower time....
So whats the paradox here?
And i ve heard that its the traveling twins accelaration when turning back to return to Earth is the most important point here!
please kindly explain this paradox to me....

Answer 1

I have included two answers that I have submitted to other questions. The first one essentially defines Paradox, while the second one relates to Einsteins special theory.
The key premise to remember regarding paradox, is that mathematical truth contradicts naive intuition. In the twin paradox, naive intuition would tell us that time would be the same across reference frames despite what acceleration might be involved. Einstein's mathematical truth contradicts this naive intuition. I hope this helps.

Yes, check out the birthday paradox on wikepedia. In essence,
this paradox demonstrates that mathematical truth contradicts naive intuition.
The problem: If 23 people are randomly selected it is about a 50- 50 probability that at least 2 will have the same birthday. Most people when confronted with this problem will intuitively estimate that selecting only 23 people will be considerably less than a 50-50 chance of having at least 2 people with the same birthday.
They will also estimate that to get to a 50/50 probability it will have to be considerably more than 23.
At wikepedia they give several different mathematical approaches to solve this problem. The best and simplest is;

A simple exponentiation
P(n)= 1-(364/365) ^(nC2)=
1-(364/365)^(23C2)=
1- (.99726) ^ (253)=
1- (.499488)=
.500511872

(nC2) is also expressed as n Choose 2...This is a factorial.
Therefore (23Choose 2) gives you 253 possible combinations.
(23x22/2x1)=253 This will be the exponent for (364/365).

With 60 people randomly chosen, this exceeds 99% chance of getting at least 2 with the same birthday.
P(n) =1- (364/365)^(60C2)=
1-(.997260274)^(1770)=
1-.00778178=.99221822

In essence, some Paradoxes can be proven false, as this one has been demonstrated. Some of our false truths throughout history have been based on naive intuition and only resolved with counter intuitive approaches. I hope this helps! GL



Below is an answer I submitted to the question "Is time travel possible"? In addition to this, Time, Size, and Mass will all seem normal for those in their own reference frame. These entities would seem peculiar, for example, if earthlings could somehow see (see in another reference frame outside their own) the people traveling close to the speed of light. The Earthlings would see the travelers shrink, become more massive, and notice that their clocks were running significantly slower. The following is a a brief description of time , the 4th dimension. I hope this helps.

Yes, one aspect of time travel is theoretically possible. That is to say, according to Einstein's Special theory of relativity it is possible to travel into the future. How far in the future in a given time span depends how close to the speed of light you accelerate. Traveling at 80% of the speed of light according to Einstein's formula y=1/ Sqrt 1-v^2/c^2 ,(v=velocity, c= speed of light) the clocks on Earth will advance 1.667 times faster than the one traveling in space. Therefore, after a twenty year journey by the space travelers, (20 yrs time has elapsed by the travelers account) upon their return, there will have passed on earth 33.4 years.
At 98% of the speed of light, 20 years of travel at this speed, upon return, 100.4 years will have passed on earth.
This is the equivalent to traveling into the future, which is a form of time travel. Therefore time travel is theoretically possible. In fact, check out this site as the guy proclaims that we will be able to approach speed of light travel within 100 yrs.
http://www.physorg.com/news10789.html......
Traveling back in time is debatable, as you would have to be able to exceed the speed of light to do that.
Plug in the numbers to this formula. speed of light c= 186,000 miles per second. For velocity, just multiply this number from .01 to .9999. Then just follow mathematical operations.
good luck

Answer 2

The traveling twin has everything slows down. Clocks, metabolism etc. relative to the twin that stays on Earth. When she returns she should be younger then her twin. Actually it depend on the time of deceleration (the time for the traveling twin to stop), provided that the traveling twin takes a few days traveling at high speed. Because that takes much time and by the time the twin stops the other may already be dead by old age.

Answer 3

A paradox is a contradiction. The contradiction here is that each twin should be younger than the other. They can't be the same age; the theory says that the first twin must be younger after the flight AND the second one must be younger. Since it is clearly impossible that they are BOTH younger than the other, that is a paradox. The usual explanation is that the one who traveled had to accelerate and therefore leave the "inertial reference frame" of the one that stays behind. Others above have described that is plenty of detail.

Answer 4

It is believed (by some) that a photon traveling at the speed of light does not age. A person traveling at a speed approaching that of light would receive partial benefit and age less than someone almost stationary on earth. The discussion is complex though.

Answer 5

When we travel at speeds close to the speed of light...according to observers than are ¨stationary¨ or moving at the speed of light our time sloes down. But we wont feel any different.So when we consider the speeding twin from the point of view of the twin on earth...we find that her time slows down. As a consequence, when she returns to earth, she will be younger than her ¨earthly cousin¨.

Answer 6

The question is one of valid reference frames. Since the traveling twin undergoes acceleration, her reference frame is not inertial and she will undergo time dilation.

Strictly speaking, the twin on Earth is also in a non-inertial reference frame due to the gravity of Earth and the Sun, but the time dilation effect of the traveling twin will be much, much greater.

Answer 7

the rationalization is that whilst the two have been in action relative to a minimum of one yet another, purely the twin contained in the spaceship grow to be speeded up. In relativity concept there's a volume called 'ideal time', that's rather the time measured by way of a clock which accompanies the observer in each and each reference physique. Observers in uniform action relative to a minimum of one yet another will see one yet another's clocks bogged down as estimated by way of particular relativity. Such observers are widespread as inertial observers. yet introduce non-uniform action (i.e. acceleration) and an speeded up observer measures a shorter ideal time than an inertial observer. purely the twin contained in the rocket perceives acceleration (the g rigidity of the rocket because it effective factors velocity), so he reviews a shorter ideal time than the non-speeded up, inertial twin lower back on earth. replace: Remo, i grow to be attempting a handwaving description of the equivalence concept of typical relativity: a gravitational field is indistinguishable from an acceleration.

Answer 8

Not enough space here to explain it all. This website does an excellent job without tons of complex math and esoteric words ==>
http://www.phys.unsw.edu.au/einsteinlight/jw/module4_twin_paradox.htm

Answer 9

here read this.