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Comment There Ain't No Such Thing As A Free Lunch (Score 1) 405

The price to the consumer is not the same as the total cost. It likely costs the USPS roughly the same amount to deliver a package as it does UPS, FedEx, DHL, etc. That you pay a lot less than that is not a marker of efficiency; on the contrary, it is a marker of the distortions in price as a consequence of Congress meddling with the USPS, which is supposedly a "private" company. Moreover, the USPS should be charging the other carriers for that last-mile delivery; if they're not charging what it costs to them to do it, then that is likely once again the fault of Congress.

Comment Re:consistency more important (Score 2) 374

25 mpg = 4 gal/100 mi
50 mpg = 2 gal/100 mi
75 mpg = 1.33 gal/100 mi

Look at gal/100 mi as a function of mpg. The difference between 50 and 25 is 25 and the difference between 2 and 4 is -2, so the slope of the tangent line is -2/25 = -0.08. The difference between 75 and 50 is 25 and the difference between 1.33 and 2 is -0.66, so the slope of the tangent line is -0.66/25 = -0.026. So the "linear" function has different slopes between different points, which is impossible, hence it is not linear at all. In fact, the curve is hyperbolic, which you might recognize from the fact that you are reciprocating one quantity to obtain the other.

Comment Re:The airwaves are public not private (Score 1) 186

In WPA-Personal (PSK) mode, the password is a shared secret, meaning that it is never passed over the air. Instead, authenticity is established by successful decryption: if I can use the password to decrypt a message I received from you, then I know that you knew the password when you encrypted it.

Technically, the password itself is not used as the key directly. It is repeatedly hashed with the SSID as a salt value to determine the pairwise master key (PMK) which is the actual encryption/decryption key. Since that key is a password equivalent (knowing it is as good as knowing the password), it is only used for the handshake process, which establishes two other keys, the PTK (pairwise transient key, used for unicast traffic) and the GTK (groupwise transient key, used for broadcast traffic), and those keys have no relation to the password.

Comment Re:Number of Digits (Score 1) 254

Both binary and decimal-in-the-ascii-format should actually have about the same entropy.

Since this discussion is about Mersenne primes and not arbitrary numbers, it doesn't make any sense to talk about entropy. In base-2, a Mersenne prime consists of a single symbol repeated many times whereas in base-10 it consists of (at most) 10 symbols repeated without any discernible pattern. The former is trivially compressible, the latter is virtually incompressible.

but plenty of higher order entropy compressors would see them as nearly equivalent

The only way to compress a Mersenne number in base-10 (or any other base not a power of 2) would be to recognize it as a Mersenne number.

Comment Re:I'm curious to see how many retailers actually (Score 1) 732

Walmart does not care one bit if you take your money elsewhere. Your spending is completely irrelevant to even one store's sales figures, and unless you have an abundance of alternatives (in which case why are you shopping at Walmart?), you'll be back eventually anyway.

In the best case, a Walmart cashier could hope to become a store manager in 15-20 years, but that doesn't grant ownership of the store. As for attempting to obtain a controlling stake in a multi-billion dollar company with a minimum wage job, surely you are joking?

What you say might make sense for "mom and pop" retail but the market is dominated by "big box" stores, for which your "advice" is anything but.

Comment Re:Cuts (Score 4, Insightful) 473

The pre-funded pension is only one part of the problem (also, accounting does not work as simply as you seem to think). The problem is threefold (at least):

1. The pension mandate (from Congress), as already mentioned;
2. The USPS is forced by Congress to run unprofitable postal offices and routes;
3. The USPS cannot set its own rates (they are set by, surprise surprise, Congress).

Either the USPS is a public service, in which case it should be reintegrated into the government and divorced of the need to make a profit, or else it is a business and it should be able to set its own rates and terms for doing so.

You cannot have it both ways and get everything you want, which is exactly what Congress has done to them.

Comment Re:Why have such short limits? (Score 2) 497

Most sites (don't know about hotmail for sure) only let you enter alphanumeric characters. That's 26 (lower case) + 26 (upper case) + 10 (digits) = 62 characters, or about 6 bits of entropy per 8-bit byte.

For a 160-bit hash like SHA-1, that's 26 characters.
For a 256-bit hash like SHA-256 or GOST, that's 42 characters.
For a 512-bit hash like SHA-512 or Whirlpool, that's 85 characters.

No secure hash (by the current standards) would limit the password space to 16 characters (that would be a 96-bit hash, roughly).

Comment Re:Wrong % (Score 1) 738

The magnitude of market share is meaningful to a buyer, although the exact number is not. If I'm going to buy a new device or a piece of software, I'm generally going to want it to have some kind of ecosystem, so that I can get support, accessories, and upgrades not only now but also down the road. This desire is strongly correlated with price, of course; a $1 app is throwaway if I don't get support; a $600 phone is not.

Never mind people who buy products because "everybody" has them, regardless of rational reasons for doing so.

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