Also remember that research is known to cause cancer in mice, and live accordingly.

Right, except that NP-hard problems don't have to be in the NP class, they can be harder. They are the problems, not necessarily in NP, that are at least as hard as the hardest problems in NP. You're thinking of NP-complete or equivalent.

No, the amount of heat released by energy production is to small to make a difference (it is tiny compared to the incoming solar radiation), and radiates to space quickly. Systemic changes to the equilibrium are the problem- mainly increasing the amount of atmospheric greenhouse gases that trap some of the energy from sunlight, but also things like changing the surface albedo through land use changes.

Because the linked article you were complaining about specified a calculation prefaced with "suppose you want to precompute the hash values for all valid characters on a US-English keyboard", about the amount of storage needed for a rainbow table. Of course there were other errors in the article, but you picked on a relatively minor part that was correct. UK keyboards have something like 13 more characters than the US one, which increases the number of possible 8-char passwords using the keys on the keyboard by a factor of about 3 relative to the US keyboard (108^8 / 95^8); and US-letters-and-numbers-only reduces the possible number only by a factor of about 30 (62^8 / 95^8). You could make a similar rainbow table for each keyboard layout, many of which have similar numbers of easily accessible characters, with a similar amount of storage to that described, so his numbers are not meaningless. So the lesson is, use a hash that incorporates salt, and don't use dictionary words as your password.

No, the digit keys all have special characters when you hold shift, and the 11 special character keys all have 2 choices as well, so there are 33 special characters on the keyboard including space. That's 95 total. Look at your keyboard and count them.

I think this throws off the rest of your calculations. The 43 numbers and punctuation together are a lot more than the 26 lowercase letters. And you failed to take into account that, even when done in a stupid way, people are likely to switch around the order somewhat (uppercase at the beginning OR end of the letters, and number/punctuation in either order, and sometimes even at the beginning instead of the end), which adds a few factors of 2 at least. Even one number and one punctuation in either order is about equivalent to two lowercase letters, but better because they help reduce dictionary words. I'm with you on explicit requirements of numbers and numbers only.

But yeah, you're better off either encouraging but not requiring some punctuation and numbers, or having looser requirements like the common "at least 1 each of 3 of the following types: upper, lower, numbers, punctuation", plus some restrictions on sequences, dictionary words, etc. It's probably a good idea to require something like at least 6 non-numbers for an 8-character-minimum password too, to keep 7-number plus 1-letter passwords from getting too popular. But if you're coming up with your own password solution (like just about everyone with the type of requirements you describe), or copying one from a non-expert, then you're probably doing it wrong.

This part is right: (26 + 10 + 11) * 2 = 94. But yeah, he forgot space so it should be 95.

They're not trying to measure energy, they're measuring peak power capacity. It's shorthand for $1/Watt fixed cost plus $0/kWh incremental cost. You'd do the same thing if you were buying a power plant ($X per MW fixed cost + $Y/kWh incremental cost), though in general the incremental cost varies and there are daily fixed costs as well. You do get that Watt for all the time maximum sun is shining on it and it is hooked up, until it stops working.

Did you forget that there are many hours in a year, and multiple square feet on a roof?

You're talking about two different kinds of waves. Matter is also a waves in the quantum mechanical sense. EM in some cases is better described by waves in the classical sense, i.e. with Maxwell's equations. Though often EM is better described as photon particles, or as photon waves that describe things like the probability of being detected at a given location.

I think it has to do with both the photon density and the size of the thing you use to observe them. If there are few photons per cubic wavelength (even less than one), EM waves look more like photons in the sense that you need to describe them with quantum mechanics. If there are many, they look more like classical waves. Also, if the wavelength is small compared to the observer, then they are more likely to look like photons. So if you have 1 photon/cm3, and a wavelength of 1cm, it might look more like a photon in that you observe quantum behavior because there is 1 photon per cubic wavelength. But if the wavelength is 1m, then there are 1,000,000 photons per cubic wavelength and you will observe more wave effects with a detector small compared to 1m, or it will still look like particles if your detector is large compared to 1m. Both views can accurately describe them, but one might be more informative in a given situation.

The size of a photon is tricky. They can be spread out over an arbitrarily large area, with a probability distribution of "appearing" at any given spot in that area. The spot in which it would appear (for example to be absorbed by an antenna) would be wavelength-sized, in the sense that this is the amount of space over which it would interact with something. I believe this means cubic-wavelength (or square-wavelength times period if you want to look at it that way), but I'm not completely sure. But if you're thinking about it as a particle, then you can probably think of it as a point, because if its size was relevant, you'd be thinking about it as a wave.

Measuring the even-numbered electron 'affects' the result of measuring an odd-numbered one (or another even numbered one) because they are entangled, not because they are coherent, though I suppose in a sense coherence would be what makes the result predictable. Please provide an example of coherence (in terms of spin only) where the particles are not entangled. I don't think it's possible, because I don't think coherence means anything useful in terms of spin only. Any two electrons would trivially be coherent (in terms of spin) because they differ by a fixed phase angle, unless in this case coherent also means in-phase (i.e. having the same spin).

You do need coherence in the double-slit experiment in order to observe a distribution of points where the electrons hit over time that match the same interference pattern they would have if they were all interfering with each other as a classical wave. If you vary the direction or energy of the electrons, for example, you would not see such a pattern.

That's entanglement, not coherence.

In your first example, they are entangled and coherent. In the second example, they are entangled and the odd-numbered electrons are coherent, as are the even ones, but they are not coherent with each other. Though I'm not sure coherence means much when only looking at a single discrete attribute like spin. I think you want either a continuous attribute, or multiple discrete ones.

The double-slit experiment (e.g. with electrons) is a better example of coherence. You shoot an electron through a double-slit. The electron-wave goes through both slits, interferes with itself, and has a higher probability of hitting in the points with constructive interference (when measured by contact with the target), and a lower probability of hitting the points with destructive interference. Shoot more electrons the same way, and they land according to the same probability distribution. The electrons are coherent because they have the same wavefunction after passing through the slits and interfering with themselves, whether they go one at a time or they are in a beam. However, they do not all hit at the same location because their trajectories are not entangled.

In the context of photosynthesis, I'm guessing this means that the electrons that are moved by the energy from the photons follow paths that are more limited than you might expect from classical physics, because the of interference in the wavefunction among the different paths. (I am also not a physicist).

Well-to-tank efficiency for gasoline is around 80%. Mine-to-power plant for coal is around 90%.

That's only relevant if the ownership or operation of the solar panels is dependent on the use of the EV. If they'd have the solar panels anyway, then the decision to use an EV mostly affects the electricity markets in the use of marginal power plants (which tend to be fossil-fuel powered), and the system-wide decisions on deploying other power sources (where the use of EVs is likely to encourage more renewables). It doesn't matter much whether the owner has solar panels themselves.

No, an EV is at most 80% efficient (plug to wheel) with current technology. It does allow more flexibility in energy sources, though you can potentially have non-fossil liquid fuels too. Gasoline cars are only limited to something like 25% efficiency (tank to wheel) if the gasoline is converted to useful energy using combustion. If you use a fuel cell, it can be much higher, which is the point of the article, using a FC instead of an ICE for extending the range of an EV.

They did include generation. Burning gas in an ICE is equivalent to burning another fuel at the power plant. They did not include fuel production in either case (you also have to dig up and process coal and natural gas). The only thing unfairly left out was transportation of gas from the refinery to the pump, which is a small energy expenditure compared to the ranges given for everything else. Given that it's just a ballpark estimate, it's not bad. The ICE efficiency and transmission losses both look a bit high, but not enough to make a huge difference.

What this shows is that BEVs are more efficient than ICEs even if you get all of your electricity from coal (and hopefully, you don't). But fuel cells are more efficient at converting their fuel source to electricity than any process involving combustion, which isn't really surprising. Of course it's best if you can power your FCEV on something other than fossil fuels, and the same goes for BEVs.

Sure I can, with 2 additional lines of code: one outer loop that iterates through all possible seeds, and another that iterates through all known pseudo-random number generator algorithms.