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Comment Re:Miss the forest for a tree (Score 4, Informative) 121

I’ve got people complaining about the lowered air quality from 2-cycle lawn blowers and trimmers when they are 0.000001% of emissions.

They are not insignificant. Blowers and mowers don't have ANY emissions control, and they spew quite a bit of unburnt crap.

Also, they should be banned because they are terrible for the health of people who use them.

Comment Re:I thought (Score 2) 197

math, objectivity, and the written word were tools of white supremacy

I mean, that's kinda true. That's how the whites were able to do the industrial revolution and get into a position where it can be called "supremacy".

Comment Re:I thought (Score 2) 197

In almost every study I've seen, the ACT / SAT do not add much predictive value once you account for high school GPA.

The problem is that GPAs can be manipulated, especially in smaller schools. Doubly so if they become the main criterion for admission. ACT/SAT are much harder to manipulate.

Comment Re:Old Starter Batteries (Score 1) 216

Not really. The battery will heat up after about 25-30 minutes of driving, so it'll be charged at normal speeds. And even a cold battery can drive your car just fine, although your top _acceleration_ will be somewhat limited.

You really can really get throttled while supercharging if you try to charge immediately after letting the car spend a night at cold temperatures, without being plugged in. This can happen, but even then you'll lose maybe 20 minutes compared to normal supercharging.

Comment Re:Old Starter Batteries (Score 1) 216

Two failure modes are common: first, there is not enough charge left for the car to prewarm the batteries; second, the charger can provide such power but if it's Chicago-cold and windy, the warmers are not powerful enough to overcome the environmental heat loss. Three hours later and the charge hasn't started.

That's not how it works. You can charge a cold li-ion battery just fine, but its internal resistance will be very high, so you won't be able to charge it quickly. It's not a big deal if you are charging using an L2 charger. Tesla pre-condition the battery before supercharging to minimize the time spent on scarce charging spots.

The second issue is that Tesla will try to warm the battery even while slow-charging, and it requires around 1kW of power. So if you're charging from a wall outlet (1.5kW limit) or a very crappy L2 charger, you might not be charging at all.

This is not an issue on superchargers, they can supply more than enough power to heat the battery: https://www.youtube.com/watch?... I personally successfully charged my Tesla after a night at -30C without preconditioning (the supercharger was located next to the hotel where I spent the night). So it looks like Chicago superchargers locations have some kind of an issue.

Comment Re:LNG (Score 1) 216

Not many people have ever had their freeze plugs pushed out, but it is better than having a cracked block.

Tesla uses propylene glycol, which contracts while freezing (-60C). So it won't shatter anything, although it might create frozen plugs in the piping. Although at -60C you probably shouldn't be driving a normal car anyway.

Comment Re:Live by the rounded edge patents, die by them (Score 1) 38

Lawyers with bad vision who probably haven't even seen their products? Yawn.

But I agree, in the pulse-oximeter case the violation was much more severe. Samsung merely made a phone that looked similar (and functioned nothing like an iPhone), Apple just stole the technology wholesale.

Comment Re:3D movies (Score 1) 59

As in, the content that wasn't compelling enough to make 3D televisions for your living room a success?

I actually love 3D TV, and I specifically bought the last OLED model with 3D support in 2018.

The thing is, there is no content for them. The only way to watch the 3D TV was to either buy physical BluRay discs, or pirated BluRay rips. There was only one 3D show on Netflix, a Spanish-language cartoon for kids. I don't want to bother with torrenting anymore, so I only bought a handful of discs with movies I like.

Comment Re:Not the same thing (Score 2) 172

Beta-voltaics are _weak_. Nickel-63 emits beta-particles at 66kEV, and you can recover less than 1% of that, so around 660eV per electron (a beta-particle). So if you need 200W to power the satellite, you need around 0.3 Ampere of beta particles. That's 2*10^18 particles per second. Nickel-63 has specific activity of 2*10^12 Bq/g, so you need around 10^6 grams of Ni-63, or around 1 ton.

You can get a more active isotope with a shorter half-life, like tritium. That'll reduce your weight by around 100x (tritium is around 4*10^14 Bq/g), and perhaps you can use more efficient generators. But we're still talking about at least hundreds of grams to kilograms of radioactive material. That's waaaay too expensive.

On the other hand, 200W can be easily generated by 1 square meter of solar panels.

Now, if you want an underwater microphone that might occasionally communicate with other sensors via bursts of encoded ultrasound, you need probably around 1W on average. So that immediately drops the amount of radioactive isotope from kilos to several grams. That's way more feasible.

There's evidence that the USSR was doing exactly that because it produced more tritium than required for the nuclear weapons program and for accounted civilian use. Tritium is also great because it's produced naturally, and if one of your microphones leaks, it'll be much more difficult to trace.

Comment Re:Not the same thing (Score 1) 172

There have been rumours floating around for years that intelligence agencies have developed betavoltaic devices for powering spy satellites.

Nobody is going to launch beta-voltaics into orbit, it's just stupid. Just slap a few solar panels, and you'll be much better off.

Nope, spy agencies and military intelligence use it in deep sea underwater microphones that are used to detect subs.

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