- #1
starstruck_
- 185
- 8
Hey everyone!
So, I just finished my 2nd year intro to SR course,
we spent most of the term on Taylor expansions for relativistic corrections vs concepts. I’ve watched a crash course video and a documentary on SR and I do somewhat understand the thought experiment involved with respect to simultaneity and such (the train and the lightning strikes) but when it comes down to more formal stuff like what’s in the Feynman lectures ( and applying those concepts to a scenario) it makes no sense. I have a bit of a inking for how I should approach a certain SR scenario but I just can’t seem to break it down.
It seems so unintuitive. I have more questions than answers.
There was an example a grad student gave us with a magician and 2 knives. The magician is traveling very fast as the knives go up and then down and the magician comes out alive.
This is my understanding of it
According to the postulates (I’m assuming ?) the same events happen in both reference frames. The magician must be alive in both reference frames (of the magician and an outside observer) and the events - knife 1 going up and then down and knife 2 going up and then down must happen in both reference frames too.
This is where my understanding diwndles. The way the diagram was set up for this scenario was similar to the train thing with the lightning strikes so that’s kind of how I tried to approach my explanation .
To the outside observer, both knives would go up and then down at the same time. For the magician however, there should be a lag I think. I just can’t understand why. I tried explaining it the same way that train scenario is explained but it’s not a complete answer.
I’m so confused. I know this has to do with length contraction and time dilation? But I just can’t figure out how to apply those concepts to this scenario. Any explanation will be appreciated!
(Please just assume I don’t know anything about special relativity).
So, I just finished my 2nd year intro to SR course,
we spent most of the term on Taylor expansions for relativistic corrections vs concepts. I’ve watched a crash course video and a documentary on SR and I do somewhat understand the thought experiment involved with respect to simultaneity and such (the train and the lightning strikes) but when it comes down to more formal stuff like what’s in the Feynman lectures ( and applying those concepts to a scenario) it makes no sense. I have a bit of a inking for how I should approach a certain SR scenario but I just can’t seem to break it down.
It seems so unintuitive. I have more questions than answers.
There was an example a grad student gave us with a magician and 2 knives. The magician is traveling very fast as the knives go up and then down and the magician comes out alive.
This is my understanding of it
According to the postulates (I’m assuming ?) the same events happen in both reference frames. The magician must be alive in both reference frames (of the magician and an outside observer) and the events - knife 1 going up and then down and knife 2 going up and then down must happen in both reference frames too.
This is where my understanding diwndles. The way the diagram was set up for this scenario was similar to the train thing with the lightning strikes so that’s kind of how I tried to approach my explanation .
To the outside observer, both knives would go up and then down at the same time. For the magician however, there should be a lag I think. I just can’t understand why. I tried explaining it the same way that train scenario is explained but it’s not a complete answer.
I’m so confused. I know this has to do with length contraction and time dilation? But I just can’t figure out how to apply those concepts to this scenario. Any explanation will be appreciated!
(Please just assume I don’t know anything about special relativity).