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Comment Re:No Headphone Jack, No Sale (Score 1) 124

if the power circuit is internally reduced to -40 (ie has soaked ambient heat overnight) it's hard to expect much of the chemistry, if it's urgent I guess jam it in your pants or armpit.

One problem with many capacitive touch displays is that they stop working if your hands are cold and dry.

Comment Re:Autonomous bikes and scooters??? (Score 1) 76

Agreed - however, the leaning of the passenger is also a big component of the stability of most two-wheel vehicles. Not having that, most autonomous two-wheel vehicles need to add a gyroscopic balancing system.

As kids, we had fun pushing our bicycles off a small hilltop and watched how they stayed upright - the one that got the farthest would "win". Most made it all the way, and my best friend had a bike that hardly ever fell over until it was at a standstill. Looking at it with hindsight, I suspect that his bike had a sharp enough front angle and heavy enough frame that it would auto-adjust better.

Comment Re:Autonomous bikes and scooters??? (Score 2) 76

Gyroscope.

This is what most people think is the reason why bikes tend to stay stable. It's also mostly wrong.
Sure, if running really fast with heavy wheeled motorbikes, the gyrostabilization effect is noticeable. But it's negligible for light bikes at lower speeds or smaller wheels.
The main reason is how the front frame is angled. As long as a bike is going forward, a dip to the side combined with the rider's weight will angle the steering towards the middle, which helps right the bike.

This is something to look for when buying the first bike for a toddler. The more angled back the steering column is, the more stable it will be. A chopper is far more stable than a pennyfarthing.

Comment Re:War on Drugs (Score 1) 355

We put more people in jail because of the war on drugs.

Only around 1 of 5 of the US prison population has drug charges as the only or main reason. Both property crime and violent crime have far more incarcerations.
https://static.prisonpolicy.or...

The ratio of incarcerations to the general population is sky high in the US compared to other countries even if every single one of the drug convicts were released.

There are many factors why the US has such a high number of inmates, including a for-profit prison system, elected judges (nobody will get elected on a promise to be more lenient than hard), but probably most of all inequality.

Comment Re:Hydrogen is a form of storage and not a good on (Score 0) 201

Nope [wikipedia.org]. You get about 9.7MJ/L for compressed hydrogen, and about 40% of that (4.3 MJ/L) for LiPo batteries.

And about 34-36 MJ/L for gasoline and diesel. That's more than four times as much energy per volume.

And if you need 700+ kg of tank to store your hydrogen - you're doing it wrong. Here's a massive 850L tank that would be equivalent energy storage to about 4800 kg of batteries - and it weighs 215 kg. Not even close.

See, here's the thing, with gasoline/diesel/kerosene, the total weight of the tank and fuel goes rapidly down as you use fuel. With hydrogen, almost all the weight is the container, so your efficiency is lower simply because you always have to move that extra mass around, even when near empty. Planes, for example, take care to not overfill so they won't have to haul more mass than needed. With hydrogen, there's little choice.

Comment Re:Hydrogen is a form of storage and not a good on (Score 2) 201

Hydrogen has about 142 MJ per kg, about 3X that of diesel and gasoline. Which themselves are about 25X that of LiPo batteries (the best, mass-producible rechargeable batteries out there). Making hydrogen about 75X the energy density of the best battery packs.

Except that the same mass of hydrogen takes up a HECK of a lot more volume.
And once you factor in the mass of the containers and other hardware needed to secure hydrogen, the advantage per mass is no longer as clear either.

Comment Srsly? (Score 2, Insightful) 384

"I worry that reading volumes of hate mail is starting to get in my head and cause me to consider the potential angry male ramifications while I'm writing my reviews, thereby compromising my integrity."

What does the word "male" do in that sentence except adding sexism? Does it matter what gender the hate mailers have?

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