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Comment Re:Coming from Detroit (Score 1) 75

There is no security on the CAN communications of any modern vehicles that I know of. Any person connected to the bus can masquerade as anyone else.

That's why Tesla has several layers of bus, with firewalls between them, inside each car.

Get on one of the buses, you get to tweak the stuff on THAT bus. But you have to convince a firewall you're cool (i.e. doing something the firewall recognizes as legitimate) before it forwards your transaction to anything on even an adjacent bus.

Comment Not quite the end of the story. (Score 1) 325

In most countries the government is in charge of health care and they have a VERY easy way to regulate price gouging such as this. In any single payer system the national health service basically sets the price they are willing to pay and that's what it costs. End of story.

Well, not quite.

In any price control regime, the authority sets the price, and there are three options:
  1. They HAPPEN to hit the "market clearing" price on the nose.
  2. They set the price lower.
  3. They set the price higher.

1. is a small target, and very hard to get right even if you're trying. (Even market economies only get there by constant feedback in the form of purchase decisions.) Further, there are strong political pressures on regulators on where to set prices, so they aren't even trying. So 1 just doesn't happen.

2. means the consumer gets gouged. (But now he can't go to some competitive supplier to get the product or service at a better price. EVERYBODY who is selling is selling at that price. So the gouging is institutionalized. The only way to get a lower price is to apply pressure to the regulators (see 1.) or go to a black market (with lots of risks, including issues of quality, reliability, contract enforcement, and bad encounters with law enforcement and the rest of the legal system).

3. is where the regulators usually end up. But a price lower than market-clearing means suppliers chose to spend their resources supplying something else, so the supply dries up. You could buy it at a sale price IF you could buy it at all. But it isn't available, so you can't buy it at any price.

A free market has its own problems. For starters, with a single supplier (a monopoly) market forces encourage gouging. With two suppliers they encourage an approximately even division of the market (a duopoly) and, again, gouging, with only price signals, not collusion, to coordinate their behavior. The incentive to engage in competition that drives the prices down to market-clearing level doesn't appear until there are three players, and doesn't become strong until there are four or more.

(Unfortunately, US regulations generally have a built-in assumption that two suppliers are "competition". Thus you get things like the landline/cable internet duopoly, or the built-into-channel-allocations local duopoly (collapsing to local monopolies) of the early, analog, cellphone system.)

Comment Knew a math professor without eyes ... (Score 1) 69

Back in the 1970s I was an undergraduate at a highly-ranked math department. One of the professors there had no eyes. (It was a birth defect - they had not formed, and his face was slightly collapsed where they should have been.)

When a student would try to skip doing some part of a rigorous proof by substituting a geometric drawing, the other profs would ask "How would you explain it to [him]?".

This guy was VERY good. But he had a "blind spot" occasionally when a graphic analogy would have pointed him to some existing proof that would apply. (I recall once when he was discussing some bottleneck in what he was working on and another professor pointed out that the troublesome piece of the problem was equivalent to an angle trisection with compass and ruler.)

Comment Re:Seven phucking photons? (Score 2) 106

Can you please convert that to Olympic swimming pools or football fields? I am american. Thanks!

So am I. Let's see...

10,000 gram moles of x-ray photons...

Take 22 pounds of hydrogen. Turn each atom of hydrogen into an x-ray photon.

Hydrogen bombs do something like that... But let's use total annihilation because the numbers are easier to find.

1 gm of antimatter + 1 gm of matter -> 43 kilotons of TNT equivalent. So call it 21.5 kilotons per gram.

Energy equivalent of a proton's mass is really close to 1 GEv. We don't know what energy x-rays they were detecting, so let's use the energy of photons from a typical dental x-ray machine: 70 kEv. So 10^4 * 7*10^4 / 10^9 = 0.7 grams of energy, or about 15 kilotons of TNT-equivalent emitted per measurement interval.

The Hiroshima bomb was estimated at 15 kilotons, Nagasaki at 20. So call it "Almost exactly one Hiroshima bomb" or "3/4 of one Nagasaki bomb" of x-ray energy released during the observation interval.

(Or maybe boost it up a bit, because I assumed perfect efficiency for the x-ray telescope's mirrors and detector, which I suspect is quite optimistic.)

How's that?

Comment Re:uninstaller unrunnable in safe mode (Score 2) 386

I don't know any company that's fallen further or faster in consumer esteem (once upon a time, a time I still recall, HP calculators represented the pinnacle of consumer esteem) except perhaps for the Hudson's Bay Company, but to comprehend that story you have to know what it once owned: a list of assets many nation states would envy. They spun off oil companies, railroads, real estate. What did they keep? Zellers.

Two words: Carly Fiorina.

Comment Re:Not "exactly" humane (Score 1) 429

Easiest method is car exhaust into a closed container via some tube.

Not since emission controls got good. There's essentially no CO (or NOx) in exhaust these days (unless, sometimes, if the car is in the sealed room and also breathing its own exhaust.) It's just a hotter and wetter version of the CO2 suffocation method.

Comment Re: F-35 is an amazing airplane! (Score 1) 192

Stealth sucks when there are multiple radars from different aspects, or using longer wave radar that stealth can't hide from.

Or radar systems where the transmitting and receiving system are separated: Those shapes are all about sending the radar signal anywhere BUT back where it came from.

(Or is that what you were talking about when you said "multiple radars from different aspects"?)

Of course the shapes are really good at their intended reflect-it-somewhere-else mode. (The engineers knew they had it right when they opened the hanger one morning and found a bunch of dead bats that had crashed into the airframe during the night. The shape had the same effect on bat sonar.)

Comment Sealing the fuel feed? (Score 1) 192

From what I can gather it is some kind of foam that is intended to prevent tank fires, fuel sloshing and as part of the aircraft leak prevention measures.

So it's a foam that (among its functions) seals leaks.

And it's peeling off the inside of the tank.

If a piece of that gets sucked over to the fuel feed it should seal up that "leak" pretty effectively. Then again, if it gets sucked into the fuel line it might seal the engine's injectors, or the fuel filter.

Any of those could make the engine suddenly stop.


Comment Re:Seven phucking photons? (Score 5, Informative) 106

Seriously? You woke me up to read about seven photons from across the other side of the solar system?

How big is the detector? How far is it from Pluto?

They detected them from the Chandra X-ray Observatory, which is in orbit around the Earth. That puts the distance between the detector and Pluto at somewhere between 29 and 50 astronomical units of about 93 million miles each, depending on where the Earth and Pluto were in their orbits during the observations.

- Calculate the area of a sphere of that radius. (That's about 10^20 square miles at the low end, abut three times that at the high end.)
  - Divide by the aperture of the x-ray telescope (0.43 sq ft), in square miles. (i.e. multiply by 1.3*10^7.) We're now in the 10^27 order of magnitude.
  - Assume the x-rays are ONLY the result of solar wind bombardment? Divide by two. (You'd have to do that more than three times to drop the number by even ONE order of magnitude.)
  - Multiply by seven photons detected.

That's a lot of photons emitted by the planet, isn't it?

Comment Planetary object detector opportunity? (Score 1) 106

By the above argument, ANY planet, dwarf planet, moon, or other solid object of substantial size, without a strong magnetic field (which would ALSO be noticeable), should be emitting some x-rays from solar wind and cosmic ray bombardment.

If this is true, perhaps this x-radiation could be used as a basis for detection of such objects?

Comment Why this insistence on atmosphere? (Score 2) 106

Why all this insistence on mechanisms involving an atmosphere? X-ray tubes don't require gas.

You get X-rays whenever you abruptly stop or deflect a fast enough charged particle (such as an electron). Pluto is a ("dwarf") PLANET, with no (known) planetary magnetic field to deflect the solar wind or cosmic radiation. Such a BIG solid body, even 'way out there from the sun, should be stopping LOTS of charged particles all the time.

(Sure, charged particles stop more "abruptly", and thus release more energetic photons, when hitting heavy atoms rather than things like hydrogen. But some of the incoming stuff will be fast enough to emit x-rays even when slamming into the bare photon of a hydrogen nucleus. And then there's the inverse case when an incoming heavy nucleus from cosmic radiation hits an electron.)

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Heisengberg might have been here.