twins paradox makes no sense .. to me T_T (1 Viewer)

[jeniii]

if both the spaceship and observer on earth see each other age slower ... how come the spaceship person comes back to earth definitely younger?

jacaranda says "the answer is that this particular problem is not reversible. spaceship has not remained inertial, it has accelerated and decelerated, turned around and repeated its accelerations. hence the two frames of referces are not equivalent and there is no paradox coz the spaceship person will be defeintly younger"

so if it accelerates away from us, time slows down. what if it accelerates towards us, time doesnt quicken does it. but isnt it relative? like.. whilst the spaceship is moving away from earth, the earth is relatively moving away from the spaceship.

"hence the two frames of referces are not equivalent and there is no paradox" - please someone explain

 

[Forbidden.]

how i think of twin paradox.

time dilation occurs only to inertial frame of reference

spaceship twin:
omfg, you're gonna be younger than me

earth twin:
omfg, you're gonna be younger than me


(50 years later relative to earth)


earth twin:
omfg why ive got a beard and wrinkles and youre still 30 ?

spaceship twin:
coz you are inert and i accelerate.
special relativity only works with inertia.
you were inert, you got to see me slow down my age.
i wasnt inert, you aged normally.


You asked:

"hence the two frames of referces are not equivalent and there is no paradox"

coz one's accelerating and the other isnt.
if they werent accelerating they would be equivalent pretty much.

 

[jeniii]

haha love the explanation!


special relativity only works with inertia.
you were inert, you got to see me slow down my age.
i wasnt inert, you aged normally.


so in other words only the acclerating spaceship will experience a slowed time and the earth doesnt? and the spaceship only sees the earth slow down because it is acclerating away?

time actually slows in the spaceship but not on earth. is that it? =D

 

[wrxsti]

Physics makes no sense and this theory is no different....... omg it seriously makes no sense.. its like when a spacecraft is accelrating and decellerating gana make a difference of 20 years...... Physics doesnt work.. they say light is constant right... yet in Einsteins thought experiment (the train moving at speed of light and a person on top of train uses two lasers) it will get the back of the train first...... lik What the heck? light is constant it will hit both at same time.... yet for some reason this stupid thought experiment "works" according to physics........ I HATEEEE PHYSICSSSSSSSSS
especially motors and genrators Stupid induced Emf
Why cant physics be like Chemistry

 

[Forbidden.]

haha love the explanation!


special relativity only works with inertia.
you were inert, you got to see me slow down my age.
i wasnt inert, you aged normally.


so in other words only the acclerating spaceship will experience a slowed time and the earth doesnt? and the spaceship only sees the earth slow down because it is acclerating away?

time actually slows in the spaceship but not on earth. is that it? =D

The Special Theory of Relativity applies in inertial frames of reference only.
the spaceship twin is in an non-inertial frame of reference and the rules dont apply to him.

(spaceship twin moves at approx ~0.99c)
earth observer: omg you're experiencing time dilation !
spaceship observer: what ??? i dont sense any difference !

time slows down on the spaceship relative to the observer on earth, but the time appears to stay the same on the spaceship

Physics makes no sense and this theory is no different....... omg it seriously makes no sense.. its like when a spacecraft is accelrating and decellerating gana make a difference of 20 years...... Physics doesnt work.. they say light is constant right... yet in Einsteins thought experiment (the train moving at speed of light and a person on top of train uses two lasers) it will get the back of the train first...... lik What the heck? light is constant it will hit both at same time.... yet for some reason this stupid thought experiment "works" according to physics........ I HATEEEE PHYSICSSSSSSSSS
especially motors and genrators Stupid induced Emf
Why cant physics be like Chemistry

the constancy of the speed of light is assumed in special relativity

somehow physics to me is the easiest subject.
just follow the goddamn dot points and pracs and youre fine.
there are at least set formulas to follow at least if you arent deriving a few.

the new hsc physics is easy compared to physics about at least a decade ago

 

[Beyond.Here]

I didn't think Twin Paradox was even in the "essential to learn" criteria.

Correct me if I'm wrong, but my teacher said it isn't part of the syllabus. Jacaranda have quite a few things that are put in there purely for the "fun" of it.

 

[MaccaFacta]

OK - confession time. I've been teaching Physics on and off for over 20 years and I only got my head around the Twin Paradox after reading an article in Scientific American Feb2006 Special Edition, which you can access through the Ebsco online database.

My problem with the Twin Paradox was that Einstein said that all velocity is relative, hence the speed of the earth relative to the spaceship was, say 0.99c, so the twin on the spaceship would see his earth twin aging more slowly.

It really gets weird on the way back, because both twins will observe the other aging more quickly because of the Doppler Effect. So, how to make sense of it?

Length contraction!

Let's say the moving twin (travelling at 0.8c) is going to a star 10 light years from Earth. According to the twin on the Earth the distance to the star is 10 ly, but the twin on the spaceship will measure the distance as 6ly because of length contraction. Hence, the twin on the earth sees his twin take a trip of 25 years (10 / 0.8 = 12.5 years to get there and 12.5 years to get back), but the twin on the ship says the trip only takes 15 years (there and back).

 

[alez]

Read a briefer history of time by stephen hawking. it explains it really well. cant really remember but i think it was soemthing to do with clocks running slower therefore less time passing when traveling near light speed

 

[Forbidden.]

Read a briefer history of time by stephen hawking. it explains it really well. cant really remember but i think it was soemthing to do with clocks running slower therefore less time passing when traveling near light speed

this sub-topic in physics is mainly theoretical physics so reading stuff from stephen hawking should help