Special Relativity Time Dilation Practice Problem

Physics Ninja looks at a Special Relativity Practice Problem. A rocket travels from earth and send a signal back to earth. I look at different event in each reference frame.

[michaellam]

I didn't know rocket can take a shit in space wow

[austinsesler]

I just want to know what poor soul took a shit so powerful that it escaped the earth at 3/5 the speed of light...Very good video though

[michaeljames]

Come on, dude, the letter T is not event close to P. Great way to get interest in your video though. Ahahaha.

[mohamedshapol]

Anyone else notice the typo? "The rocket shit"

[aleksandrsimonov]

Am I the only one who noticed "the rocket shit" at the beginning of problem

[ricky]

Me sees the word shit in the presentation

*Immediately scrolls to the comments*

[ricky]

whenever someone makes a typo like that I immediately check the keyboard to see if the letters are close to each other. t is not close to

[JohnDixon]

13:20 "The rocket must measure a dilated time for both of these events" but wasn't the rocket's time of 1 hour considered proper time? Is there something I'm missing?

[bittuhalder]

You are really good in understanding us

[Mnemonic-X]

Does anybody know that only one inertial frame of reference has time dilation relative to the other one.

Einstein was the stupidest scientist ever😄

[jessylecool]

What if the rocket turned around as it was sending the signal? Would we change "+3/5*(ct)" for "(-3/5)*ct" because of the fact that the Earth is now moving towards the rocket ?

[NiteshKumar-qdzu]

Very nice explanation, you cleared my all doubts about time dilation.
Thanks

[anselmrafael]

I get a) and b), but when you’re doing c) I fail to understand why the earth would be moving away from the rocket. There should be a frozen coördinate where the signal is emitted by the rocket, and then it just travels (3/5 c)m at a speed of c. So in 3/5 hours. Then the final answer would be 8/5 hours. In your calculation however, the earth moves away. So you’re basically trying to find the point where the light (that travels faster) catches up. But why is the earth moving? Should you always pretend the other object is the one that is in motion? Also why does the rocket have the proper time whilst it is the thing in motion. Wouldn’t that mean time goes slower in the rocket and therefor the lorentzfactor should be reversed?

[micrchap]

Would some kind whizkid here please tell me the velocity of a spacecraft moving (as a fraction of C) for an arbitrary 1 Hz signal sent from it to reach stationary Earth?

[tech-helpbuddy]

I have a doubt that in the rocket frame if the earth is moving away with 3/5 c then signal which is traveling with c should be seen moving with 3/5 c + c by the observer at rocket frame but in part 3 you have not considered that to calculate time ..why?

[frankdimeglio]

The ultimate unification and understanding of physics/physical experience combines, BALANCES, AND INCLUDES opposites, AS E=MC2 is CLEARLY manifest as F=ma ON BALANCE; AS ELECTROMAGNETISM/energy is gravity. Here's the proof. This also explains why objects (including WHAT IS THE FALLING MAN) fall at the SAME RATE (neglecting air resistance, of course), AS E=MC2 IS CLEARLY F=MA ON BALANCE; AS ELECTROMAGNETISM/energy is gravity. TIME dilation ULTIMATELY proves (ON BALANCE) that E=MC2 IS clearly and necessarily F=ma ON BALANCE, AS ELECTROMAGNETISM/energy is gravity. Gravity is ELECTROMAGNETISM/energy ON BALANCE.


ON THE CLEAR, EXTENSIVE, SENSIBLE, BALANCED, THEORETICAL, AND UNIVERSAL PROOF THAT ELECTROMAGNETISM/energy is gravity, AS E=MC2 IS clearly PROVEN TO BE F=MA ON BALANCE:


Balanced inertia/INERTIAL RESISTANCE is fundamental, as ELECTROMAGNETISM/energy is gravity. The stars AND PLANETS are POINTS in the night sky. Energy has/involves GRAVITY, AND ENERGY has/involves inertia/INERTIAL RESISTANCE; AS gravity AND ELECTROMAGNETISM/energy are linked AND BALANCED opposites; AS ELECTROMAGNETISM/energy is gravity; AS E=MC2 is CLEARLY proven to be F=ma ON BALANCE. This NECESSARILY represents, INVOLVES, AND DESCRIBES what is possible/potential AND actual IN BALANCE. Indeed, A PHOTON may be placed at the center of what is THE SUN (as A POINT, of course); AS the reduction of SPACE is offset by (or BALANCED with) the speed of light (c); AS ELECTROMAGNETISM/energy is gravity ON BALANCE; AS E=MC2 is CLEARLY F=ma IN BALANCE !!! Gravity is ELECTROMAGNETISM/energy ON BALANCE, AS E=MC2 is CLEARLY proven to be F=ma IN BALANCE. TIME dilation ULTIMATELY proves (ON BALANCE) that ELECTROMAGNETISM/energy is gravity, AS E=MC2 is CLEARLY F=ma ON BALANCE. Gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE, AS ELECTROMAGNETISM/energy is gravity; AS E=MC2 is CLEARLY F=ma ON BALANCE; AS the stars AND PLANETS are POINTS in the night sky. Accordingly, ON BALANCE, the rotation of WHAT IS THE MOON matches it's revolution. TIME is NECESSARILY possible/potential AND actual IN BALANCE, AS ELECTROMAGNETISM/energy is gravity; AS E=MC2 is CLEARLY F=ma ON BALANCE. The stars AND PLANETS are POINTS in the night sky. Accordingly, ON BALANCE, it makes perfect sense that THE PLANETS (including WHAT IS THE EARTH) will move away very, very, very slightly in relation to what is THE SUN !!! ELECTROMAGNETISM/energy is gravity, AS E=MC2 is CLEARLY F=ma ON BALANCE. Inertia/INERTIAL RESISTANCE is proportional to (or BALANCED with/as) GRAVITATIONAL force/ENERGY, as this balances gravity AND inertia; AS E=MC2 is CLEARLY F=ma ON BALANCE; AS ELECTROMAGNETISM/energy is gravity. GREAT. I have explained the cosmological redshift AND the supergiant stars. Stellar clustering ALSO proves ON BALANCE that ELECTROMAGNETISM/energy is gravity, AS E=MC2 is CLEARLY F=ma IN BALANCE !!! 


By Frank DiMeglio

[larshansen]

For part a, when determining proper time, why can't you say do the same thing but with the earth? i.e there are two events, one where the earth is here, and one where it is here. In the earth's frame of reference both happen in the same place, but from the rockets POV, they happen in different places, therefore the earth experiences proper time?

Does the concept of "proper time" only exist relative to the events in question? So because the events I described are different than the ones in the video, that is why proper time changes?