Cap'n Refsmmat

But you're enciphering each repeat letter (such as both ls) with the same number. If I guess the right base, that will be represented by repeated digits in that base. So I can do a frequency analysis. Basically, if I guess the right base, you only have a monalphabetic substitution. It seems like if I guess the wrong base, then the frequency distribution of digits won't be right to match an alphabet. A proper one time pad requires every letter of the message to have its own key, not just every letter of the alphabet.

So I'd pick a large number (the "base value") and assign each letter to a number smaller than the base value. The cute part is then summing up the letter as though each were a digit in that base arithmetic. So if someone intercepts your message, let's assume they know the system but don't know the base or the character assignments. If the base is small (e.g. less than 216 or something), a brute-force attack wouldn't take long. Just iterate from base 1 to n; for any base n, convert the decimal message into base n and read out the digits. Now you have the ciphertext letters, which are a simple monalphabetic substitution; you can do a frequency analysis to test if it's plausibly an enciphered English message. If the frequency analysis shows no normal English pattern, try n + 1. There may be a cleverer mathematical attack but I haven't put too much thought into it. (It just so happens that I'm currently reading David Kahn's excellent The Codebreakers, which you might enjoy. It describes many historical cryptosystems and their solutions, along with a great deal of history of their use and abuse.)

I don't follow your post. If I wanted to encrypt the message "Cap'n Refsmmat", how would I do that? What key would need to be shared between me and my recipient?

Paper money is always interesting under a loupe because of all the tiny details and anti-forgery measures you can find.

The two are not mutually exclusive, as your use of the term "libertardians" demonstrates. Since this thread is clearly going to go nowhere, I'm going to end it now. If you want to discuss why you were banned, well, you know where to contact me.

No, I think display name changes are restricted to members who haven't become Senior Members yet. I'll make the change for Bonerfart here soon. Okay, changed. You'll still log in as Bonerfart, but everyone else will see Cosmobrain.

This is the direct link: http://mirrors.ctan.org/systems/win32/miktex/setup/basic-miktex-2.9.5105.exe

The great big "Download" button on the left is actually a really evil banner advertisement. It has nothing to do with MikTeX. Avoid it.

I have used Qt in Python (with PyQt) to good effect. It's pretty comprehensive, although that means it takes a while to figure out how to do what you want.

Airplanes are cylindrical tubes. The lower level is hence narrower. For example: So you'd fit fewer passengers on the plane. That's quite a big cost. And what about landing gear failure? That's fairly common, and now you'd have the passengers bear the brunt of the impact. So you have to put everyone in a five-point harness with pyrotechnic devices to fold the tray tables out of the way. They can't put their backpack or purse under the seat in front of them, in case it gets in the way of ejection. You also have to supply a life raft or survival gear for every seat, in case they come down over water. Also, landing under parachute without training is a great way to break an ankle or a leg. Airplanes are already safer than cars, buses, or trains per mile traveled. Aviation safety is great. The FAA uses an interesting system for cost-benefit analysis. Every passenger's life is assigned a monetary value, and the cost of the safety measure weighed against the expected passenger value saved. Ejection seats would be fantastically expensive and mostly ineffective.

You'd pay quite a lot more, since the airplane wouldn't be able to carry cargo with passengers ejecting through the hold. Military pilots get extensive training on landing with a parachute and surviving in the ocean, desert, or wherever they may come down. Also, what fraction of aircraft accidents are the sort where the passengers would be able to eject?

They probably rounded some of the numbers off, so they don't quite add to 100. That happens pretty often in tables of percentages.

Since the disappearance, various commercial satellite imagery providers have started searching sections of the ocean. But it's pretty damn big. There's a website where you can view the images and tag anything interesting you spot: http://www.tomnod.com/nod/challenge/mh370_indian_ocean Many people have already looked, but there's plenty of ocean to scan.

Yeah; when a guy hijacked a FedEx flight to commit suicide, he tried to disable the cockpit voice recorder before takeoff by flipping the circuit breaker. The pilots noticed and turned it back on: https://en.wikipedia.org/wiki/Federal_Express_Flight_705

You can explore the situation in both reference frames (stationary observer and moving flashlight) here: http://www.refsmmat.com/jsphys/relativity/relativity.html#flashlight In short: you always see the light traveling away from you at the speed of light. (Of course, you can't drive your car at the speed of light--only infinitely close to it.)

USB delivers five volts, so everything will use the same charging voltage. That's not terribly bad -- there's a huge quantity of electronics already designed to be powered by 5V USB power.

I would hope that they intend to standardize the connectors, rather than the physical charger. You can already buy micro-USB chargers with varying power ratings, for instance; makers of phones like yours can supply a micro-USB charger with a low power rating, but you can also plug the phone into a big beefy charger for a more powerful phone, since the connector is identical.

Yeah, FPSRussia is known for putting small explosives in his targets. Makes the videos more fun. He's also done videos to promote new video games. I believe the quadrotor in this video is actually from Call of Duty: http://callofduty.wikia.com/wiki/MQ-27_Dragonfire So yeah, it's a viral marketing job, not a real drone. Pretty sure the drone is CGI in the video, judging by how it moves.

Isn't this just Time Cube?

One you have made ten posts, yes. We don't allow signature edits before then to avoid spam.

Well, it is a bad analogy; Susskind talks about the probability that an electron will radiate light along its trajectory, but conflates that with the probability that it will emit one upon impacting the phosphor screen. Those are two different events, and as swansont points out, the phosphor screen always radiates. So placing the analogy inside a television didn't help at all. The numerical problems pointed out by swansont could be excused as reading a metaphor too literally, but beyond that it's just weird. But I'll excuse that. Explaining a tricky scientific concept is hard, and I usually go through a pile of candidate explanations before I hit one that works.

Yes, and it was a poor analogy. Can we call it good now? Susskind wrote a pretty good book which is still pretty good, though some bits have been superseded by newer experiments and works, and he made an analogy to explain the fine structure constant which we don't think holds up very well. The end. I'm not sure what there is to argue about.

That was not the point in question. Do we really need to start the same tedious argument over again? This discussion is the product of classic Internet Argument Failure, where the argument is really just a series of squabbles over smaller and smaller details that relate less and less to the original point.

I see you use LaTeX to typeset your books; I'm impressed by the quality of the design. (But then most self-published textbooks I see just use \documentclass{book} and Computer Modern and don't bother with anything else.) I do notice the following license restrictions: That's unusually restrictive for an openly-licensed textbook. Why did you choose this license? Admittedly my book is a much smaller undertaking, but I went with a much looser license.

Spell checking should be a feature of your web browser, not the forums. So you should figure out how to turn it on in Chrome/Firefox/Safari/IE/whatever you use.