Special Relativity: Crash Course Physics #42

This video is pure gold! Thanks for the clarity in the explanations and the amazing motion graphics that accompany them.

it’s counterintuitive but trust me. the human conception of time slows, and things shrink 😂

It’s ok to make longer videos.

Best illustration of these concepts I've seen in 60 odd years. Thanks

Why are you speaking at the speed of light?

The only thing that does not vary because light is God

PBS was there when I was a kid and is still there when I’m an adult.

Thank you so much for your ideal development of every aspect of the tutorial.

Excellent simple explanation

Great video. Awesome host.

Couldn't you speak any faster? Like near the speed of light?

"Is your brain hurting yet?"
Yes, yes it is. Man, relative physics really gets your brain to work hard which is probably the reason why it's so interesting!

I dont get why bob sees the front lightning struck first then the back

She talks way too fast...

Thers is a third postulate: You will never understand this.

Do y'all think the beginning of the video sounds like American Boy

Beautifully explained. But I think it's time we ditch the speed of light being a constant. Time is not tangible and cannot be dilated. The speed of light must be shifting

Great, but please slow down! I can't follow that quickly

Thanks for this explanation

I'm so disappointed that Cthulhu didn't win the election 3 years ago

Come onnn u talk faster than a speed of light i cant catch a thing my brain isnt braining anymore

don't understand length contraction, she has a quick clock, more time passes for her as the train speeds by, shouldn't she measure a normal length and the conductor a short length

i do not understand

Ship1 at rest at top.
T--------------------N
<----- N----------T
Ship2 at rest at bottom.
T----------N ----->
N--------------------T
The moment when T of ship1 is lined up with N of ship2 must be the same moment in both frames of reference because there is only 1 moment when this occurs. At this moment, for someone at N of ship1 to see T of ship2 they have to look in 2 different directions simultaneously. This is impossible. N of ship1 has simultaneously both passed and not passed T of ship2. This is impossible because it means that there was a point in time in the past when N of ship1 was lined up with T of ship2 for one ship but not for the other ship.

Your presentation is incomplete. You applied only one postulate in your example ( the speed of light) . You did not however apply the principle of relativity. I wonder why all these type of videos leave that out?

I don't understand why you are speaking at the speed of light

I saw you on Philomena Cunk

I’ve been struggling with this at uni and this video made it so clear, thank you!!!

I still cannot digest that if I move faster than light i will stay young while other who are not moving will become older🥴

"But you're measuring a longer time than Bob is." How? Can someone please explain this to me?

What the

I love your content!! ☺️ but, I would love it more if you specify your sentences a bit more.

I have a question if the train is moving at half the speed of light then the speed at which bob and the mirrror are moving is half the speed of light yes? so when bob flashes light on the mirror, the light travels two times as fast as both bob and the mirror are moving therefore the light hits the the mirror and reflects back to bob faster than he and the mirror are moving so distance remains the same whether he's moving or not because light is two times faster than him and the mirror. So my question is if this is true then why are we saying that for the second reference the light travels diagonally at a longer distance?

Thank you❤🌹🙏

Did anybody notice the westworld reference?

This is actually quite a simple thought experiment with the assistance of mathematics

The man in the train also sees a vertical light of the woman outside as going through a longer path so the same should apply to him..

this was very well explained, thank you!

Wow, I understand!!

I don't understand the bit about the two flashes of lightning occuring at a different time when you're on a moving train. I understand that you won't see them at the same time, because it takes a while for the light to reach you, but you can calculate how long it would take the light to reach you to see how long ago the lightning strikes actually did occur. Like when I observe a star, based on how far away the star is, I know I'm really observing the star from a million years ago.

i did not understand fiskskxkd

bruh why is this so hard to understand

I'm amazed how Einstein found this out using nothing but D=T*V and Pythagoras Theorem.
I think I have a pretty good understanding of Time Dilation. I'll study further for Length Contraction.

i watched this several times. changed the speed to 0.5. turned on the closed caption and still didn't get the main idea.... homayghaaad may pamileee...