Watch electricity hit a fork in the road at half a billion frames per second

Comments · 9.9K

• AL

  @AlphaPhoenixChannel · 2 years ago (edited) · pinned

  Corrections and FAQ in this comment!<br>Check out the other channel for follow up videos, and video Q&amp;A that I&apos;ll be posting in a few weeks with questions from here and from Patreon! <a href="https://www.youtube.com/@AlphaPhoenix2">https://www.youtube.com/@AlphaPhoenix2</a><br>Check out the Patron page if you want to support the channel, get early access to videos, and join us on Discord! <a href="https://www.patreon.com/AlphaPhoenix">https://www.patreon.com/AlphaPhoenix</a><br>Thanks to @ElectroBOOM for giving me a sanity check on this data a few months ago! (I hope you like the final video)<br>FAQ:<br><br>0) Questions about the experimental setup (including the effect of the probes on the circuit while I was measuring) are here! <a href="https://www.youtube.com/watch?v=sty0Y1qmgEY">https://www.youtube.com/watch?v=sty0Y1qmgEYc</a> If anybody wants to recreate this project, or turn it into an undergrad physics lab. hopefully there&apos;s plenty of info there! If I can remember how to use github I&apos;ll post some of my visualization code and leave a link on that video.<br><br>1) Lots of commenters have that I&apos;m confusing voltage and current at times, but I tried to be very careful with my language. Current is the actual motion of the electrons, and in the graphic I showed with the blue dots moving around, I&apos;m calculating that motion based on the voltage. it&apos;s basically the current that is NECESSARY to produce those voltage patterns. I also did a measurement where I measured the current directly by placing a very small resistor at the input lines and measuring the voltage drop across it over time, so I know my calculation lines up vaguely with that, but it WAS only a measurement at one point. If somebody wants to put a quarter ohm resistor every 4 feet along a wire and measure more voltages, I&apos;d LOVE to see the data! I&apos;ll talk about the script a bit more in the Q&amp;A video that hopefully will be out in a few weeks!<br><br>2) When you first flip the switch, the battery doesn&apos;t actually see a &quot;dead short&quot;. The current out of the battery initially is limited by the line impedance, which depends on the properties and dimensions of the cable. In this case, it&apos;s the same current you&apos;d get by bridging the switch with a 150 ohm resistor!<br><br>3) A lot of people have questioned the use of the words &quot;communicate&quot; and &quot;sending information&quot;. I admit I anthropomorphize a bit too much in this video, but particles and groups of particles &quot;communicating&quot; and the rate at which &quot;information&quot; can move are very important hard physics terms that don&apos;t imply the particles are thinking. &quot;Information&quot; here consists of things like partical position, and they pass this information between each other using the electric field.<br><br>4) Water is a compressible fluid. if water wasn&apos;t a compressible fluid than pressure wouldn&apos;t work and water wouldn&apos;t be able to flow around corners in pipes. The way I&apos;m using it it&apos;s actually EXTREMELY compressible (in the lateral) direction because it&apos;s allowed to expand upwards without getting significantly denser. Electrons in a wire are orders of magnitude less compressible than water, but it&apos;s still worthwhile to think of them bunching up!<br><br>5) ...........keep the comments coming! i spent like 4 hours reading comments yesterday lol

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• CA

  @cameronbehar7358 · 2 years ago

  That bar graph animation was one of the single best scientific visualizations I’ve ever seen, all the more compelling because it’s empirical, not simply modeled. Fantastic.

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• 3B

  @3blue1brown · 2 years ago

  Excellent video, those data-driven animations are extremely clarifying. I&apos;d never seen someone show a circuit settle into a steady state like this, thanks for putting in the effort.

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• GL

  @glennbrymer4065 · 1 year ago

  I&apos;m a 73 year old former power generation specialist. I started learning about electricity when I was 7 years old. This is hands down the best explanation of how current travels through wiring &nbsp;I have ever seen. <br>Very well done young man.

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• AN

  @anoriolkoyt · 1 year ago (edited)

  The incredible aspect of the visualisation used in <a href="https://www.youtube.com/watch?v=2AXv49dDQJw&amp;t=647">10:47</a> is that even before the addition of the battery, the system is &quot;alive&quot;, that there is a still voltage changes in its &quot;static&quot; state without any added force, for whatever reason. Internal nuclear forces? &nbsp;External electromagnetic interference? Heat gain because AP is touching the wire? Computational errors linked to software? To hardware? &nbsp;Who knows! Its a great example of how experiments must be careful to identify rogue variables, and to what extent those variables could change the results. &nbsp;The variations in voltage in the &quot;static state&quot; are neglible <b>relative to</b> the impact of the addition of the battery. &nbsp;So its a variable that can be considered as a constant. &nbsp;This is very important and fundemental pillar of science, imho.

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• JA

  @jakobmoderl3331 · 2 years ago

  Fun fact to this video: Since the waves reflect once there is a change in the wire, e.g. an &quot;unexpected&quot; open end because the cable was damaged somewhere, the time between connecting the battery and the the arrival of the reflected wave can be used to measure how far away the fault in the wire is (its called reflectrometry). This is extremly useful when diagnosing where cables buried in the earth are damage so that you can dig up exactly the damaged section instead of having to dig up kilometers of wires until you find the faulty section.

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• TA

  @taylankammer · 2 years ago

  IMO this is hands-down one of the best physics channels on YouTube. Your ability to turn highly abstract and complex concepts (like the &quot;speed of movement&quot; which is a video I&apos;ll never forget because it blew my mind) into real-life experiments using actual measuring equipment is just amazing.

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• BL

  @BLBytes · 1 year ago

  I’m a ham radio operator, and one thing I’ve always struggled with is how antennas work. An antenna is basically just the open circuit you demonstrated. The reason that we have to make antennas very specific lengths is to create a standing wave of voltage. The more pronounced that standing wave is, the more energy is radiated as EMF. <br><br>I know your goal in this video wasn’t to explain how an antenna works, but your explanation really made that make sense to me.

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• AN

  @andyandy4459 · 1 year ago

  As an electrician and now a controls technician, thank you so much, you answered the question I had since grade school, as well as some technical stuff about communications wiring

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  @1776FREE2 · 2 years ago

  “In this video we’re <i>actually</i> going to be able to record this circuit fast enough to differentiate between these four options.”<br>What a Time to be alive!

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• AB

  @abhijithcpreej · 2 years ago

  This channel is like a saving grace to people who already know the math and feel the physics but don&apos;t quite get it. It feels so good to understand what you thought you knew.

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• TH

  @theslowmoguys · 2 years ago

  Absolutely amazing “footage.” Who needs expensive cameras when you can get such good data from an oscilloscope. 🤯

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