*sigh*…youtube

I like to watch videos on youtube. Mostly I enjoy experimenters, people building stuff. It gives me ideas sometimes, but mostly I just like to see what other people are doing. I don’t know what the reason is, but a lot of people seem like they couldn’t be bothered to spend 5 minutes googling something before talking out of their ass about it. I see this over and over again. People not understanding volts, amps, or basic mechanics, or any number of other things. These things aren’t hard. I guess the saving grace is that they’re experimenting or building or whatever, but how far do you think you’re going to get if you don’t understand the basic principles?

One of my favorites is watts. A watt is a really simple concept. It’s power, or more specifically, a unit of power. It’s a construct that describes in one numeric term, a combination of factors (volts and amps) in a system. But a lot of people don’t seem to understand what it is, or more accurately, what it doesn’t describe. In talking about complete solar systems for instance (ones complete with a battery of some kind), people will often refer only to “how many watts” the system can deliver, and what sorts of devices could be powered. Well, that information is meaningful, and it isn’t. Saying that a hair dryer takes 1100 watts is just telling you how much power it needs. And a hair dryer, or light bulb (or any resistive load really) are pretty simple. So I could concede “how many watts” might be kind of useful there. But what you’re really describing is the instantaneous amount of power that can be delivered. You’ve say NOTHING about for how long. If you had a perfect little AA alkaline battery, with very little internal resistance (or a capacitor), it could theoretically run that hair dryer. Obviously, we know that isn’t true, but the “how many watts” answer could say it was possible. It would “run” for fractions of a second probably, but who cares? That’s not what you asked. Watt hours on the other hand IS meaningful. It’s very meaningful. A laptop battery will usually have a label listing its capacity in watt hours. Even cell phone batteries will usually list their capacity in amp hours (which could be translated into a variety of watt hour figures, given certain circumstances). But for a little googling, and god forbid…reading, people could avoid these silly misunderstandings. It boggles my mind. Do you want to understand something, or do you just want to fuck around? Fucking around is fine, you might learn some things, but you’re not putting it on any kind of foundation, and honestly, it could be dangerous.

Another one I saw recently that drove me nuts was people claiming they could build “gravity engines” or generators. The basic principle behind this is to use a mass weight, pulling down on a geared mechanism that changes the slow rotation of the falling mass into a fast rotation. People were claiming this could be used to run electrical generators. I never saw one of those in action (of course). One person had simply built a small fan attached to the fast rotating gear. Fair enough. That’s about the best you can expect from something like this. It’s a really neat concept, don’t get me wrong, but all these people are not understanding torque. Sure, that little gear my be spinning at 4000 RPMs, and sure, you could put some magnets on it and throw some coils next to it. But as soon as you start drawing ANY kind of load through those coils, it’s probably going to stop. This is the same reason it’s crazy hard to pedal slowly in the highest gear of a bicycle. Sure, if there was no road resistance, you could pedal the wheel extremely fast in that gear, but there’s very little torque behind it. I’m not sure if it’s the same term, or if generators use a different term for it, but in electric motors, there’s a concept of back EMF, or electro-motive force. Basically the idea that a motor spinning is also “generating” a current in the opposite direction of the current driving the motor. With coils under load and the low torque spinning disc, the effect is analogous. If you kept the load light, and the mechanism very strong, and used a heavy enough mass, you could probably engineer some usable power out of it. But to claim “oh look at that rapidly spinning gear!” as though there was this abundance of power to be harvested there is just delusional.

Now I don’t want to discourage people from experimenting and trying crazy things. Please do! That’s how I started. But I realized you will get too far off the path of reality if you don’t understand the basics. You absolutely don’t need to understand all the details, and in fact, it’s probably better you don’t, so you’re not discouraged from thinking outside the box. But understanding the basics will help you call bullshit on that no-torque generator, or the 1000 watt power system that can only put that kind of power out for 15 minutes. The internet is here for you. There are countless people out there who love the stuff you love, and want nothing more than for you to really understand how it works.