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Comment Re:Yes it is (Score 4, Interesting) 140

It's not just irradiance (W/m2) that counts for retinal damage for two reasons. 1. Removal of heat is much more efficient from a small spot than from a big spot (3D versus 2D heat transfer). 2. Involuntary drift of the eye spreads out the dose if the spot size is small. (Try fixing your gaze at a spot for 10 seconds - you can't).

Some of the camera damage was in the aperure blades. Those were not in the image plane of the lens (similar to your irises). Those get quite a bit more dose if there is a big-diameter lens in front of them.

Disclosure: years ago, I reasoned that you wouldn't get blind from looking into the sun for 0.3 seconds, with binoculars, based on your irradiance argument. And tested it. Well, I didn't get permanent eye damage, but the after-image was 8x bigger in diameter than that of the sun with the naked eye and lasted for a day - rather disturbing. That was before I learned about the mechanisms of laser-induced damage.

Comment Re:it's gotten ridiculous (Score 1) 105

Why would there be much labor? Cameras aren't mounted in the dashboard

The monitors are (I quote you: "and that's including the monitor!"). You want the camera without a monitor to hook into the already-present dashboard monitor syste? Now you need to ensure that the camera and the dashboard hardware talk to each other reliably even though they are made by different companies. I've had a phone where the camera would occasionally stop working until a reboot.

The automaker is buying *millions* of the same camera. You've never heard of price breaks?

The company I work for sells expensive industrial equipment that costs our customer tons of money if it's malfunctioning due to a faulty component (and we are on the hook, too, if the yearly downtime hours exceed a certain threshold). The components that we buy from our suppliers need to comply with many pages of requirements and the suppliers need to provide a paper trail of all the quality checks and test results. Believe me, that does not make things cheaper. I suppose that the car industry is more price-conscious than we are, though.

You say: "it's cheaper because they buy them by the million". I say: "it's probably not cheaper because of (1) quality differences, (2) labor/logistics costs, and (3) need to have the same camera model on stock for 10 years." But neither of us really knows the numbers.

Comment Re:it's gotten ridiculous (Score 1) 105

You can get Chinese backup camera systems on Ebay for under $100 now, and that's including the monitor! The cost to an auto OEM for just a backup camera is going to be a fraction of that.

I wouldn't be so sure about that. Car manufacturers have to factor in the serviceability. If a camera system breaks during the warranty period, they are on the hook for the cost of the replacement, which may involve disassembling the dashboard of the car (i.e. lots of labor hours.), not to mention the reputation damage if it turns out that the camera system of car X tends to break within 3 years. Hence, they have a quite different requirement on reliability than a private person who orders a gadget from Ebay. And they need to ensure that spare parts will still be available for the next 10 years.

Comment Flaws in the invention (Score 4, Informative) 105

If you look at the front-page figure and Fig. 1 in the patent application, it will become apparent that the device only works for light rays entering at one particular angle. Essentially, it's like looking through louvers with an aspect ratio of 1:4 (fig. 1) or 1:6 (front page), which means that you won't be able to see through at all if your eyes are off by 25 cm horizontal at 1 m distance (i.e., passenger-side pillars) and whatever you see is substantially obscured for smaller angles. This is roughly how those 3M privacy screens for laptops work. That might be barely acceptable for the passenger-side pillars, but would be completely unworkable for the driver-side pillars.

Moreover, the surfaces 126 and 146 in Fig. 2 will need to be polarizing filters or opaque black surfaces so that you don't get to see spurious overlaid images. If you make them black, you will have replaced the obscuration of the pillar by two big black sheets that are only invisible if you look at them from one particular angle. If you make them polarizing absorbers, good luck in manufacturing those such that they don't reflect at grazing-incidence angles. (Those surfaces are mentioned in paragraph 37, without further reasoning about the benefits or tradeoffs, suggesting that the inventors don't know yet how to deal with these issues.)

By the way, the inventors have the polarizations the wrong way around in the figures. Although the correctly mention that p-polarization is transmitted and s-polarization is reflected, they have the arrows indicating the light polarization the wrong way around...

Comment Re:Bit of disinformation going on here. (Score 1) 52

A bit of apples and oranges. Wifi is restricted to max 20 mW or so with an omnidirectional antenna, less if you use a directional antenna. Telecom uses higher power (250 mW on the phone from a quick Google) and uses high-gain directional antennas at the cell tower. You would't be allowed to use such high powers in the unlicensed wifi band.

Comment Re:But it's rooted... (Score 1) 255

It's difficult to do because Google provides this root detection service (Google Safety Net). That 'snet' program is self-updating and probably runs with elevated permissions. Whenever a developer releases an easy-to-use and somewhat popular root-hiding tool, Google will implement a tailored detection scheme for that particular tool and silently roll it out.

Comment Re:Why (Score 1) 201

Adiabatic compressed air energy moves the heat from compression into an insulated thermal mass chamber, and uses that to heat the expansion vessel. It recouperates that loss and has 70% total effective energy storage--higher is possible, up to 90%.

The way you describe it sounds not at all like an adiabatic (no heat exchange) process but rather like a thermodynamically irreversible process. Maybe you mean an isothermal process?

And from :
"real compressors and turbines are not isentropic, but instead have an isentropic efficiency of around 85%, with the result that round-trip storage efficiency for adiabatic systems is also considerably less than perfect."

Wikipedia doesn't say so much about isothermal compression in practice, but it sounds to me like practically infeasible to reach your 70-90% roundtrip efficiency. You'd need an enormous thermal mass that doesn't change much in temperature despite 1/3 or so of the energy being stored as heat, you need enormous heat exchangers to transfer the heat with negligible temperature differences, and your compressors and decompressors need to have a very high efficiency.

Comment Re:What bugs me about USB power (Score 1) 152

IMHO: A USB device that depends on its power source to limit its input current, and can be damaged by a host that is willing to deliver more current that it requested, is defective by design.

Current limiting is to protect the supplier of the current. Bad current negotiation can damage the power supply, so of course the power supply should limit the current. A bad power supply may break, though. I think the main problem is that USB-C can use a range of voltages and a 5 V device plugged into a 20 V power supply will blow up the device unless the 20 V supply is signaled to throttle back to 5 V.

But maybe I misunderstand. Unfortunately, the reporting about this topic (Leung's findings) is very fuzzy about what happens exactly. But I don't see any scenario where connecting a good quality 5V, 1A or 2A charger to any USB-C device can lead to damage.

Comment Re:I Stopped Using Custom ROMs (Score 1) 215

"your uncommon hardware may get burned out early (I've lost many wifi / gps / bluetooth / 3g-4g chipsets that way)."

This is the first time I hear smt like this. Do you have evidence?

The gps radio in my nexus 5 (with CM) tends to deteriorate over the months, but it turned out that tightening the screws of the rf shield restores the reception. Not a software issue.

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