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Comment: Re:Body hacking (Score 2) 86

by Captain Segfault (#45291577) Attached to: MIT Wristband Is a Personal Climatizer

while the extra centripetal acceleration draws blood out closer to my fingertips.

I think you mean "centrifugal force". Note that a centripetal acceleration/force would be pulling your blood back inwards from your fingertips; you're looking for the equal and opposite force that is pulling the blood away.

Physics teachers who say that there is no such thing as centrifugal force are lying; it is every bit as real as gravity. It is a white lie, with the point of avoiding accelerating non-inertial reference frames. Such physics classes will show that centrifugal force is entirely explained by inertia in a reference frame undergoing centripetal acceleration. That's great.

Here's the problem: those same classes will regularly describe gravity as a force. The thing is, once you study general relativity you realize that gravity (and in particular the 9.8 m/s^2 acceleration you feel downward) has exactly the same explanation; space-time is curved by the mass of the Earth such that the surface of the Earth needs to accelerate upwards at 9.8 m/s^2 in order to remain "in place".

In other words, centrifugal force is entirely as real as gravity. If it is centrifugal force that makes your blood move out, don't be afraid to say it.

Comment: Re:Trading term (Score 1) 91

by Captain Segfault (#45107213) Attached to: Oil Traders Misread Tweet, Oil Prices Spike

Putting money in every paycheck is great and exactly the way to go, but isn't "dollar cost averaging". Dollar cost averaging is something else and entirely bogus.

Suppose you get $120K. DCA advocates would tell you to invest, say, $10K of it every month into your preferred asset allocation, rather than investing it all at once.

On the other hand, suppose your cat walks over your keyboard while you're logged into your brokerage and sells $120K of stock. Do you invest it $10K at a time or do you just reverse your transaction immediately? Hopefully it is obvious that you do the latter -- but this scenario is exactly equivalent to the first one.

Comment: Re:And it's in Japan (Score 2) 268

If you're going to do a comparison like this you really need to count just the 23 special wards (14,485 per square kilometer). Tokyo the prefecture-equivalent "metropolis" includes a lot of areas which are essentially suburban sprawl west of Tokyo -- the Tama area. I don't think anyone would really consider, for example, Hachioji to be part of Tokyo the city, but it is a substantial fraction of Tokyo metropolis -- and if you're coming up with a number as low as 6,810 you're including it.

This is complicated by the fact there is no longer a government for Tokyo City, which is what used to be the 23 wards. The wards themselves are cities, somewhat comparable to a more independent and smaller form of NYC Boroughs. Conversely, Tokyo metropolis would be something like a separate State of New York City which includes both the Boroughs and Long Island and a couple of small islands in the Caribbean.

With that said, there's no ward of Tokyo which is as dense as Manhattan. mostly because there aren't a lot of tall buildings. The technology to build earthquake resistant skyscrapers is relatively new compared to a lot of the construction.

United States

+ - GOP opposes net neutrality, internet piracy->

Submitted by
ericjones12398 writes "While GOP candidates won't stop publicly disavowing it, all eyes are on the Republican platform. The convention, which closed Thursday, inserted a number of controversial planks regarding abortion, English-only laws and a committee to examine the possibility of returning to the gold standard. Receiving considerably less attention was the downright Orwellian naming of the "Internet freedom plank," which opposes net neutrality."
Link to Original Source

Comment: Re:"Tenfold"? (Score 1) 271

by Captain Segfault (#38761392) Attached to: Faster-Than-Fast Fourier Transform

This result was rather interesting for SODA because it wasn't an improvement in time complexity over the best known algorithm. There are asymptotically faster previously known algorithms for computing sparse FFTs, but they aren't actually faster than the current (extremely optimized) FFT implementations unless the output is extremely sparse.

This algorithm isn't quite as asymptotically fast but it has a much better constant factor, so it is more likely to be effective in practice on inputs which are not extremely large and/or outputs which are not extremely sparse.

For God's sake, stop researching for a while and begin to think!