UptownMaker

Chris Gammell, of  Chris Gammell's Analog Life  and  The Amp Hour ,  tweeted  about  this gizmo . Not surprisingly, it set off his bullshit sniffer, and mine too. So, let's do a tiny little bit of physics and find out if their claim to a fully charged iPhone battery in 2.5 miles is legit. First, the assumptions: 1. My mass is 75kg. I wish, but that's close enough. 2. My stride length is about 6 feet, so 3 feet per step. A little long, but probably close enough. That gives me about 4400 steps in that 2.5 mile walk. 3. I lift my foot about 10mm with each step. 4. An iPhone battery has about 1500mAh of battery life, which, for an average LiPo battery voltage of 3.7V, translates to 5.5wh, or approximately 20kj of energy required. For a standard gravity, 10mm step height, 75kg person, and W = f x d, we get 7.35j per step. 4400 steps gives us 32kj total generated; we need to capture 20kj of that to charge the phone. That's 62.5% of the energy generated. ...

Caveat lector--this post has nothing  to do with making anything. Except the aforementioned kerfuffle. First things first--I am absolutely aware of my privilege. I'm a cis, hetero white man, of unexceptional girth and slightly more than average height. I have no scars, no birthmarks, no differences of ability which would draw the eye. In short, I'm playing the Game of Life on the lowest possible difficulty level, and damn lucky for it. So. A few months ago (right before Hogswatch  Christmas), I decided to start painting my fingernails. I've always wanted to--or, at least, since I was at least a preteen--but I've never had the courage to do it. I'm not prone to an action such as this simply for attention or to be "different". I simply realized that, for the first time in my life, I was comfortable enough with myself and my life to scratch a long-denied itch. My beautiful wife bought me many varieties of polish, and I've been painting my...