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Comment Re:Geo-fencing, nothing more. (Score 2) 188

"If stuff is bought with a stolen credit card then the credit card company or the bank bears the risk."

I highly doubt that; the thief could have a friend set up an online merchant, make $2000 purchases of virtual goods and split the profit.

The reason merchants are so careful is that the merchants will have to eat the loss in case of a fraudulent transaction.

Comment Re:I only go... (Score 1) 415

... very painful death by lockjaw unless you vaccinate against it roughly every 10 years, aren't you? A tiny little scratch suffices, especially when you're in contact with earth or rusty metal. Even an old razorblade can kill you ...

From https://en.wikipedia.org/wiki/Tetanus : Objects that accumulate rust are often found outdoors, or in places that harbour anaerobic bacteria, but the rust itself does not cause tetanus nor does it contain more C. tetani bacteria. ... Hence, stepping on a nail (rusty or not) may result in a tetanus infection, as the low-oxygen (anaerobic) environment is caused by the oxidization of the same object that causes a puncture wound, delivering endospores to a suitable environment for growth.

it is unlikely that a little scratch would create the necessary anaerobic conditions. And unless you keep razorblades buried in soil, those are not likely to carry the spores either.

Comment Re:Bad idea. (Score 1) 189

Did you remember to factor the cost of life in?

No, only the gut feeling that 1e-7 per year is a very low risk compared to e.g. the risk of getting killed in traffic (1e-4 per year). What I read is that F3 tornadoes can usually be survived by staying in an interior room; for F4 and F5 you need an underground shelter or reinforced room. The question is more whether it makes sense financially to build the entire house tornado-resistant or even spend $10,000 on a storm shelter.

telling them that those lives are only worth as much as the insurance.

It is cold, but the value of life is estimated to be around 7 M$, based on how much people want to be paid to take risks, and on what (government) measures to prevent loss of life cost. Based on that, a measure that increases the survival probability for an F4/F5 tornado would be allowed to cost about $1 per person per year.

Disclosure: Tornadoes don't affect me as I live in Netherlands. I should be more worried about flooding...

Comment Re:Bad idea. (Score 4, Informative) 189

People who decided not to live in plywood boxes in tornado country, or in wildfire area or below the sea level between a lake and the sea, or below the river level etc should not be asked to shoulder the burden

For hurricanes and floodings, which could devastate large areas in a single event, I see your point. However, a single tornado usually impacts only a small area. The probability of an individual house in Tornado Alley being struck by an F4 or F5 tornado seems to be 10^(-7) per year. Economically, it makes more sense to insure the risk than to build an F4-tornado-proof house. I couldn't find probabilities for F3 tornadoes, but I could imagine that a similar argument holds there.

Comment Re:Gross, but... (Score 1) 618

If a Pharma company invented any of them today there is no way they'd even be allowed for use with a prescription, let alone stocked in 500-count bottles

Here in Netherlands, they are not allowed to be sold in greater quantities than 20 pills, just to reduce the perception that they are harmless. The strange thing with paracetamol toxicity is that it would be trivial to add a harmless antidote against overdosing to the pills, but this isn't done despite the fact that paracetamol poisoning is the most common type overdose of pharmaceutical products.

Comment Re:Infared Contact Lenses? (Score 1) 320

Another poster posted a link to a youtube clip of these contact lenses. They come with built-in fake irises, so only the pupil appears dark. Regarding the definition of near infrared: the standard range of visible light is assumed to be up to 740 nm, but I have worked with 800 nm near-IR lasers for many years and they are still visible, although a 1 watt beam appears to be comparable to that of a 1 mW laser pointer at 675 nm. See for yourself here for the sensitivity curve: http://cvrl.ioo.ucl.ac.uk/cvrlfunctions.htm (under fundamental spectra or luminous efficiency).

Comment Re:Gross, but... (Score 1) 618

You seem to be stating that if I accidentally took 3 paracetamol pills,

See https://en.wikipedia.org/wiki/Paracetamol_toxicity . Short version: maximum recommended intake is 3 grams per 24 hours; a single dose of 10 g can be fatal, as are a few days in a row at 10 g per day spread out over multiple smaller doses.

Comment Re:Infared Contact Lenses? (Score 1) 320

if you put one layer on top of the other, even transparently, I am not sure.

Ink on paper works like this: the paper acts as a diffuse reflector; the ink absorbs light for certain wavelengths, but the light that is not absorbed passes through without changing direction. Putting two layers of ink with different absorption wavelengths on top of each other will result in only the wavelengths that are *not* absorbed by either being reflected by the paper. This is the whole point of the CMY(K) printing process.

Maybe you are thinking of paint, which typically includes its own reflective particles. But paint needs to be applied in a much thicker layer (0.1 mm or 4/1000 inch) to do its job, so it would be rather noticeable; the deck of cards would be 5 mm (1/4 inch) thicker and you would be able to feel the paint with your fingertips.

Comment Re:a few laws of physics problems here (Score 1) 90

But if you collecting acoustic data over a period of time, transient sounds (noise) average out, and the loud peak (gunshot)

Well yeah, if you want to pinpoint the source of a massive transient or the source of an annoying continuous whistling sound or a never-ending repeated playback of some secret message, this sensor could work. But it would not be very useful for recording private conversations.

But look at it from this side: a normal microphone measures pressure as a function of time, i.e. p(t). If their is only one source of sound, you can reconstruct the sound wave at the source. If there are two sources, it becomes impossible to distinguish. This transducer will generate three signals: vx(t), vy(t), and vz(t). If you have three sources of sound, then you could, with proper tuning and calibration, disentangle the signal and reconstruct the output of each of the sources individually. As soon as there are more than three sources, say in a pub with 20 conversations going on at the same time, you cannot do this anymore simply because there are more bits of data being transmitted than being transduced; you would need to solve a system of three equations with twenty unknowns.

Comment Re:Infared Contact Lenses? (Score 1) 320

... a well chosen filter can indeed make two light bundles look different that look exactly the same without the filter.

Yes, that's what makes the skin look weird under cheap white LED lights and older fluorescent tubes. This effect is called metamerism.

But unless you print the entire back sides of the playing cards with a pattern of two different inks that look the same under the casino lights but look different through your filter, you cannot use this to label cards after the fact. Ink absorbs light, so when applied to white paper, the surface will look darker than before, no matter what.

Comment Re:Infared Contact Lenses? (Score 1) 320

...IR detector card has a strip of chemicals on it that glow pink when a remote control is aimed at it.

That is not frequency doubling, but a special form of phosphorence. Visible/blue light is used to generate long-lived excitations in the molecules. Infrared then excites them further to a slightly higher level with a short excitation lifetime; as that excitation decays, it emits visible light. It shares the disadvantages of common phosphorence: it is not directional.

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