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

Corrections and FAQ in this comment! Check out the other channel for follow up videos, and video Q&A that I'll be posting in a few weeks with questions from here and from Patreon! youtube.com/@AlphaPhoenix2 Check out the Patron page if you want to support the channel, get early access to videos, and join us on Discord! www.patreon.com/AlphaPhoenix Thanks to @ElectroBOOM for giving me a sanity check on this data a few months ago! (I hope you like the final video) FAQ: 0) Questions about the experimental setup (including the effect of the probes on the circuit while I was measuring) are here! https://www.youtube.com/watch?v=sty0Y1qmgEYc If anybody wants to recreate this project, or turn it into an undergrad physics lab. hopefully there's plenty of info there! If I can remember how to use github I'll post some of my visualization code and leave a link on that video. 1) Lots of commenters have that I'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'm calculating that motion based on the voltage. it'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'd LOVE to see the data! I'll talk about the script a bit more in the Q&A video that hopefully will be out in a few weeks! 2) When you first flip the switch, the battery doesn't actually see a "dead short". 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's the same current you'd get by bridging the switch with a 150 ohm resistor! 3) A lot of people have questioned the use of the words "communicate" and "sending information". I admit I anthropomorphize a bit too much in this video, but particles and groups of particles "communicating" and the rate at which "information" can move are very important hard physics terms that don't imply the particles are thinking. "Information" here consists of things like partical position, and they pass this information between each other using the electric field. 4) Water is a compressible fluid. if water wasn't a compressible fluid than pressure wouldn't work and water wouldn't be able to flow around corners in pipes. The way I'm using it it's actually EXTREMELY compressible (in the lateral) direction because it's allowed to expand upwards without getting significantly denser. Electrons in a wire are orders of magnitude less compressible than water, but it's still worthwhile to think of them bunching up! 5) ...........keep the comments coming! i spent like 4 hours reading comments yesterday lol

I have a PhD in physics. That graph is easily the most instructive, intuitive thing I've ever seen about electricity and it's relationship to the wave properties of the electric field. Absolutely incredible experimental design and presentation.

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

That graphic at 10:50 is amazing.

I am PhD Biomedical Engineer (hons electronic) and also MD (medical doctor). Congrats on excellent video. The same thing (wave reflection) happens in your body every time your heart beats. The outgoing wave in the large arteries reflects off the capillary bed and you get amplification of the pressure (equivalent to voltage) on the leading edge of the (systolic) pressure pulse. Not only that but as you age the blood vessels get stiffer (lower capacitance) and the distal impedance increases, further increasing systolic pressure. Of course you also get a multitude of reflections at every branch. Congratulations, if you understood what I just said you understand more about this than almost all doctors. PS. I have the exact same oscilloscope next to my monitor right now!

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.

Fun fact to this video: Since the waves reflect once there is a change in the wire, e.g. an "unexpected" 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.

When you said "and then I spent hours stripping wire at hundreds of locations to attach the probe clips" I rolled my eyes and thought whyy?!. But your determination to follow through is what makes this so special! Brilliant combination of experimentation, video, narration, and the data-driven animations... really impressive.

This man made a career out of disproving Veritasium. Good job! and Thank You!

Well this is ridiculously cool. This makes electricity make so much more sense, and what an amazing visual!!!

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

Channels like this will upend higher education institutions and SHOULD. Love this so much.

Wow. I have a Ph.D. in Electrical Engineering, and I am impressed at how clear and effective this video is. Excellently done!

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

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

This is just incredible work on the split wires and then the tapping with all those measurements and the graphs. This is just unbelievable work. I did not think we would get that detailed of an answer and hadn't even made a guess. Just amazing work.

That is an amazing, intricate, time consuming and number crunching experiment and you basically proved that electric waves behave the same as ultrasound and other waves. For over 15 minutes I was yelling at my screen "CAPACITANCE!" It's almost like you heard me...

Your vids have already changed my understanding of electronic fundamentals, but this visualisation in particular absolutely took it to the next level. Thanks.

As an RF Engineer, the stuff you're talking about is my daily bread an butter. Still, I've never seen such a good visualization of electromagnetic waves, let alone based on actual measurement. Really cool and educating, even for professionals!

This might be the best video I have seen on YT. I can see how much work you put into it. And seriously, thank you for doing it. I studied EE and I left school not truly understanding it: none of this was covered in school, at least not in a way that made electricity intuitive. Years later, I feel so much more informed about what I studied. Thank you for your dedication, curiosity and creativity.