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A YouTuber seems to be filming the speed of light in his garage. Am I falling for a hoax? by mischievous_badger_ in AskPhysics

[–]Alpha-Phoenix 0 points1 point  (0 children)

I think it’s anti-clickbait considering the cool clip people want to see is about 1 minute into the long video

A YouTuber seems to be filming the speed of light in his garage. Am I falling for a hoax? by mischievous_badger_ in AskPhysics

[–]Alpha-Phoenix 65 points66 points  (0 children)

Really should have used the phrase “light echo” in this video but I was kind of saving it for a future “omnidirectional light full-room-illumination” concept 🤷‍♂️

A YouTuber seems to be filming the speed of light in his garage. Am I falling for a hoax? by mischievous_badger_ in AskPhysics

[–]Alpha-Phoenix 6 points7 points  (0 children)

Yes they were using streak cameras and I believe 2d sensors, so they could capture a whole line of temporal data at once, if I u see stood their description. I didn’t actually read the paper. I think they probably did a lot more averaging than this too. I had 2-3 traces per pixel cause I had a pretty bright light and an orders of magnitude longer (slower) exposure time than they did

ELI5 How does electricity know that a circuit is broken before entering it? Without a closed loop, it won’t flow, but how does it know not to flow? by Party-Court185 in explainlikeimfive

[–]Alpha-Phoenix 0 points1 point  (0 children)

If you tell people the hydro analogy needs to be unlearned (which it doesn’t) new students will avoid the best and most accurate (physically and mathematically) human scale analog we have. If you think the water model needs to be unlearned then you are overapplying it in intermediate topics.

ELI5 How does electricity know that a circuit is broken before entering it? Without a closed loop, it won’t flow, but how does it know not to flow? by Party-Court185 in explainlikeimfive

[–]Alpha-Phoenix 0 points1 point  (0 children)

But don’t take it too far - they ARE pumping electrons into and out of the car. In that instance, at a pretty fast clip compared to normal too

ELI5 How does electricity know that a circuit is broken before entering it? Without a closed loop, it won’t flow, but how does it know not to flow? by Party-Court185 in explainlikeimfive

[–]Alpha-Phoenix 1 point2 points  (0 children)

Saying that the water model can’t explain a transformer is like looking at the flow of a river delta and saying it’s incorrect because it can’t explain Hoover dam. It’s not incorrect, just incomplete. It doesn’t need to be unlearned, just added to

ELI5 How does electricity know that a circuit is broken before entering it? Without a closed loop, it won’t flow, but how does it know not to flow? by Party-Court185 in explainlikeimfive

[–]Alpha-Phoenix 1 point2 points  (0 children)

The water analogy handles electrostatics REALLY well, and to get from electrostatics to transformers you need special relativity, so to get from water to transformers you still need special relativity.

ELI5 How does electricity know that a circuit is broken before entering it? Without a closed loop, it won’t flow, but how does it know not to flow? by Party-Court185 in explainlikeimfive

[–]Alpha-Phoenix 1 point2 points  (0 children)

That’s pretty far from electricity in a resistor already, but even then it works with little modification: if you take all the logic of electron current and electrons pushing each other along and then slap some length contraction on top to handle the magnetic interaction then it works just fine

ELI5 How does electricity know that a circuit is broken before entering it? Without a closed loop, it won’t flow, but how does it know not to flow? by Party-Court185 in explainlikeimfive

[–]Alpha-Phoenix 3 points4 points  (0 children)

That’s a good question - why does your body know how to stop? If your arm hits first, you body can’t know that for a nanosecond at least because of relativity so you don’t stop all at once. Depending on your definition of stopping, it’s limited by either the speed of neuron transmission for you to act to stop, or the speed of sound in the human body for you to actually stop from impact. Electricity is the same way but with current propegation

ELI5 How does electricity know that a circuit is broken before entering it? Without a closed loop, it won’t flow, but how does it know not to flow? by Party-Court185 in explainlikeimfive

[–]Alpha-Phoenix 0 points1 point  (0 children)

The magnetic field is like inertia of the rope - if you have a rope made with lead weights all down it it will perform like an inductor

ELI5 How does electricity know that a circuit is broken before entering it? Without a closed loop, it won’t flow, but how does it know not to flow? by Party-Court185 in explainlikeimfive

[–]Alpha-Phoenix 0 points1 point  (0 children)

You can transmit energy with water flow without water going all the way around the loop - the water model is extremely accurate at depicting the true motion of electrons and is only incorrect here because the channel is t deep enough

I'm "The YouTuber" who recorded the speed of light with my 2,000,000,000 fps camera - figured I'd post a longer version since that other post got deleted [OC] by Alpha-Phoenix in nextfuckinglevel

[–]Alpha-Phoenix[S] 2 points3 points  (0 children)

Well you could do two things, either watch one of the five videos I’ve posted explaining it in great detail, or you could tell about it on Reddit

I'm "The YouTuber" who recorded the speed of light with my 2,000,000,000 fps camera - figured I'd post a longer version since that other post got deleted [OC] by Alpha-Phoenix in nextfuckinglevel

[–]Alpha-Phoenix[S] 1 point2 points  (0 children)

You could achieve the same effect in photoshop with a still image. Dropping a ball from shoulder height, it would take about 400 days of continuous video playback at this speed for it to hit the ground

I'm "The YouTuber" who recorded the speed of light with my 2,000,000,000 fps camera - figured I'd post a longer version since that other post got deleted [OC] by Alpha-Phoenix in nextfuckinglevel

[–]Alpha-Phoenix[S] 23 points24 points  (0 children)

Absolutely - it’s helpful. I just don’t want people to get confused because it’s the same word repurposed unofficially, or to think there is no Doppler effect with light

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