#even taking a lowish average size per tooth

[bookshopsbizarreblog]

Did you know that you'd need to eat ~260,000 human teeth every second to fuel the Flux Capacitor?

Okay, so, the sources behind this beautiful statistic

As is stated a number of times by Doc Brown, the Flux Capacitor requires 1.21 gigawatts of power

According to a 2017 article by Science.org, eating all of someone's teeth would give an average of 36 calories [1]

The typical adult human will have 32 teeth, including their wisdom teeth. I don't know whether the 36 calorie statistic was taken with or without wisdom teeth, so I'm going to assume that it's with them. That way, we get a bigger number of teeth!

And the math!

Gigawatts are a bit frustrating to work with, because we can't just get a specific amount of teeth we'd need to eat to power it. Much like a 100 watt light bulb, that number is about how much energy it consumes every second of its operation, rather than a set quantity we need. And since it is stated that the time travel happens instantaneously (and looking at the frame-by-frame of the stop watches demonstrating the time travel shows that they are still synced, further showing this) [2], there is no time for the energy consumption to happen within. So whatever number of teeth it would take to fuel the Flux Capacitor via metabolic processes (assuming all of the calories a human would gain from digesting teeth are perfectly transferred into electrical energy and ignoring the energy cost associated with digesting the teeth in the first place) needs to be some rate of teeth / time.

So let's break it down unit conversion style

To turn that formula into plain English, we start by finding the energy each individual tooth has. If a set of them has 36 calories, and there are 32 in a set, then each tooth is 1.125 (36/32 -> 9/8) calories. By flipping that number, we are expressing that, for every calorie we wind up needing to run the flux capacitor, we will need 8/9ths of a tooth.

Next, we can convert the (food) calories into joules. They both measure the same thing--energy--and they're just different units for it. Similar to how feet and meters work. Joules are more useful for this formula, since joules and watts are easier to convert between, and the flux capacitor's energy requirements are measured in watts. Each calorie is 4184 joules, so we just convert between them.

Then we can covert the joules directly into watts! A joule is a watt second, meaning that something that consumes one watt of power for one second will have used a joule of energy. To use the example of the 100 watt lightbulb, if it was running for 1 second, it would use 100 joules. If it was running for 2 seconds, it would have used 200 joules. And so on.

(a watts * b seconds = a * b watt seconds = a * b joules)

Now that we've converted from calories to joules, and joules to watt seconds, we have:

The section on the right is splitting out the different aspects to make it slightly easier to understand. Essentially, this formula is saying that for every 4,707 watts of power we need, we must consume one tooth per second. That isn't a lot of teeth,,, yet. Unfortunately, 1.21 giga-watts is a lot of watts. 1.21 * 10^9 of them, to be precise. And after running that number through the calculator, we get a grand total of 257,064 teeth per second. But as we don't know the exact number of calories per teeth, it's safer to round up to ~260,000 teeth per second.

So, if Doc Brown built his DeLorean with the capacity to metabolize teeth at 100% efficiency, he would need to feed it around 260,000 of those enamelous little morsels every second to travel through time.

[1]

[2] https://www.youtube.com/watch?v=HV6wO_UVfWo