New world record with an electric racing car: From 0 to 100 in 0.956 seconds

Indeed. It's a case of "my favorite kind of car isn't the best performing anymore, but I refuse to accept that, so I'm going to change the definition of performance instead."

Something weird about this is that humans very often ascribe the sensation of d^ns/dt^n, to feeling d^n-1s/dt^n-1.

So people will say that something which accelerates quickly is 'fast'. Or they will say, when they feel themselves initially being pressed back into their seat as a plane starts its takeoff roll, that they are experiencing 'acceleration' when what they are experiencing is actually jerk.

The thing is, you can't actually feel motion at a constant speed - so the only thing that tells you you are acquiring speed is your body's experience of acceleration - so when you feel yourself accelerating, you associate that with speed. Likewise, your body also can't really tell the difference between constant acceleration and just... being at a different angle, and maybe a bit heavier than normal. So it's when you experience changes in the apparent direction of 'down' and the overall 'weight' you're feeling that you think 'oh, we're accelerating'.

My favorite way to get a sense of what acceleration, jerk and snap feel like is to focus on what happens when you're in a car that's braking hard. You're decelerating at a relatively constant rate while the brakes are applied - it feels as if 'down' is pointing slightly forward, meaning you'd be sliding off the seat if it weren't for your seatbelt holding you back. When the car finally stops though, there's a very abrupt change in acceleration - a 'jerk'. 'Down' switches to pointing straight down again, very quickly. You're pulled back into your seat. That's jerk. And specifically the sudden onset of that swing in what direction 'down' is pointing, and then its rapid disappearance is snap. Your body feels like it's being 'jerked' around when the car stops precisely because that motion has high snap - you experience a sudden high amount of jerk, then the jerk ends.

> Factories used to have bands and axels taking power from one central steam engine to all corners of the building. And then they got redesigned once electricity came in.

Fascinating fact you might enjoy: many modern industrial facilities use compressed air to power many of the devices inside.

At a lot of Amazon facilities, a main compressor is somewhere on site keeping a large tank full. The compressed air is piped throughout the facility[0], and used to power a lot of moving parts in an open loop, making a distinctive 'hiss' sound[1] as the device moves and releases air. Not everything, certainly, but a lot of simple devices that need to move quickly and with some force.

It's all computer controlled and yes, electricity is a major part- but the driving force is coming from compressed air. And that's pretty neat.

[0] (Or so it was explained to me by the controls tech guys there)

[1] https://www.youtube.com/watch?v=Y5Hf08XrI_A (the first 30 seconds or so it's really noticeable).

Torque is directly proportional to radius, all other factors being equal. There are practical limits on the strength of the magnetic force because you can only cram so many amps through a confined space, which is even more confined on a small motor.

It will still make high power at high RPMs, but you have to gear it down to convert that power into more torque at low speeds. A gearbox makes it not really a Hub Motor at all any more. Terminology aside, a gearbox also adds even more weight and complexity inside the wheel. For less weight and complexity you can use a half-shaft to the center of the vehicle and use whatever motor you want inboard.