MinutePhysics Special Relativity Series

[SiennaTheGr8]

Speaking of which:

 

[ZapperZ]

Still waiting for the next chapter for the MinutePhysics series. In the meantime, Don Lincoln continues with his own series on Special Relativity, and his new video appeared today. This time, he tackles velocity addition.



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[SiennaTheGr8]

As soon as I saw the subtitle of the video I knew he'd make the error he makes at 6:11, when he talks about observers traveling toward each other at the speed of light. The "1 + 1 = 1" business is just wrong. It's really "$1 \pm \, v = 1$," with $0 \leq v<1$:

$\dfrac{1 + v}{1 + (1)(v)} = 1$

and

$\dfrac{1 - v}{1 - (1)(v)} = 1$,

where the latter equation explicitly rules out $v = 1$.

 

[ZapperZ]

This is Chapter 5 of the MinutePhysics SR series.



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[ZapperZ]

Here's Chapter 6 of MinutePhysics's Special Relativity lessons. This time, they are tackling something that we get asked about on here ad nauseum - relativistic velocity addition.



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[ZapperZ]

Chapter 7 of MinutePhysics's Special Relativity lesson. This time, it tackles on what is meant by spacetime intervals.



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[David Lewis]

Don Lincoln is coincidentally delving into many aspects of SR at almost the same time. So here is another video by him. This time, he's tackling the concept of "length contraction".

Don said: "If you start with a basketball, and accelerate it at high speed, it'll look like a pancake."

It will be shaped like a pancake but unless you're very close to it, the basketball will look spherical, and rotated way from you.

 

[Nugatory]

Don said: "If you start with a basketball, and accelerate it at high speed, it'll look like a pancake."

It will be shaped like a pancake but unless you're very close to it, the basketball will look spherical, and rotated way from you.

Everyone watching/reading this thread has to be aware that in this context the word "look" has to be taken literally - it's what you'll actually see based on light traveling to your eye along paths of different lengths from different points on the object.

 

[ZapperZ]

Chapter 8 of MinutePhysics's Special Relativity lesson. This time it is on the Twin Paradox, and he uses the thingmajiggy to illustrate the concept.



You may supplement this video with the one done by Don Lincoln a while back that tackled the same topic and using the same explanation.



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