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Comment Re:The duck quacked (Score 1) 285

I come here to see the news picked apart in the discussions, not to get the latest breaking headlines. I therefore find either a paywalled link (so I can't RTFA), or a discussion about a previous paywalled link which doesn't match the article I'm reading.

However, thank you for taking the time to answer us. I'm more optimistic for Slashdot's future knowing that you've given thought to this and are making a reasoned decision.

Comment +1 for Mairix (Score 2) 177

After trying several solutions I settled on Mairix. Searches are screaming fast (less than a second to search several hundred thousand emails), indexing is fast, it's reliable (no problems in the 5+ years I've been using it), and the search language is easy and flexible.

* I use procmail to send a copy of everything to an archive, rotated monthly
* The archive is therefore just a handful of mbox files
* I have a cron job to run "mairix -Q" every 5 minutes, and "mairix -p" nightly
* I have this in my .bashrc: "function search() { mairix -o $$ $* && mutt -f ~/Mail/$$ ; rm ~/Mail/$$ ; }"
* And here's my .mairixrc:


With the above, I can find:

* everything from slashdot in the last two months: search f:slashdot d:2m-
* any emails I sent containing "squishy" in the body: search f:subreality b:squishy
* messages with "password" or "passwd" or similar in the subject: search s:passw=
* get a quick summary of the search language: search -h

It's so good that I download all my email from my work Gmail account so I can search it... sometimes Google's search just isn't precise enough to find what I need.

Comment Censorship is not the answer (Score 2) 452

Creating a widespread system of censorship is not the right approach:

1) It violates the principles the United States was founded on.
2) Suppressing the free flow of information deprives people of the liberty to make their own informed decisions.
3) When other opinions are squelched, the communication channel becomes a propaganda channel and loses all credibility.
4) This infrastructure will be abused. Now, ISIS. Next, common criminals. Eventually, dissidents.

Comment Re:Don't Use UTC (Score 2) 143

Are you sure YOU know the difference between UTC and GMT?

It's not that UTC sounds cooler... It's what we actually use. UTC ticks based on atomic clocks and it's what's distributed through NTP. GMT (really UT) tracks Earth's rotation, doesn't have a stable second, and there are no high-precision realtime references.

Most programmers just need to know the number of seconds since Midnight, Jan 1, 1970, GMT, as God intended.

time_t doesn't count the number of absolute SI seconds since the Epoch: it assumes days are always 86400.0 seconds long, and completely ignores leap seconds... even worse, before 1972 they used sub-second leaps, so the offset isn't even an integer.

So, all told, why not refer to it as UTC since that's actually correct?

Comment Re:No kidding (Score 2) 103

The fact that you get /a/ face isn't profound, but the resulting image is interesting. It gives a good picture of the things that human vision uses to locate faces: obviously the eyes and mouth are most prominent; there's moderate contrast for the cheekbones and nose; the oval shape is only vague; the neck, ears, eyebrows, and hairline are almost entirely missing.

I expect those are already well known to vision specialists, but to me, it's an interesting analysis of the exact details which make an inanimate object become a face.

Comment Re:Power usage? (Score 4, Informative) 94

My Arduino projects don't require the power of a 32-bit processor, but do run on batteries. How much more (... or less maybe?) power is drawn by this processor?

It's reasonably close. If you check the datasheets for "Static Characteristics" / "DC Characteristics" you'll find:

The LPC1114FN28 (the ARM chip) draws 9ma @50 MHz, 6ua @deep-sleep, and 220na @power-down;
The ATMEGA168PA (typical Arduino-ish AVR) draws 4.2ma @8MHz, 0.8ua @power-save, and 0.1ua @power-down.

These numbers are just for the chips - the Arduino draws considerably more (about 40ma @idle), and you can stretch your batteries a lot by hacking it. To give a sense of scale, the power LED on an Arduino probably draws 5-10 ma just by itself.

Note that this is a "Cortex M0" profile ARM chip - M means Microcontroller, and 0 means low-end. This is a 50 MHz chip with 32K of flash and 4K of RAM. It's more powerful than an AVR, but don't expect to boot Linux on your breadboard with this thing... that's a job for the Cortex A (Application) series.


Comment Re:Hydrogen and Helium? (Score 1) 35

But doesn't the gas form part of the reaction mass? And therefore using a lighter gas would give less thrust? Eg might sulfur hexafluoride be better?

No, these are water rockets. The reaction mass is water. :)

Even if the gas was reaction mass you'd probably want a light gas. A heavy gas might have better impulse per mole or per liter, but lighter gasses will provide more impulse per gram. At some point the larger pressure vessel will add more mass than you're saving on the gas, but I'd expect the optimal gas to be closer to the hydrogen end of the spectrum. Take that with a grain of salt though because I haven't made any attempt at the math.

Comment Re:Hydrogen and Helium? (Score 2) 35

So, I'm super curious to hear what you think pressurized hydrogen or helium would provide that pressurized air would not.

1) Lower mass. Air at STP is 1.2 g/L. Hydrogen is 0.09 g/L. Looking at the contest rules the pressure vessel has to contain 20% water, so most of the volume is gas. A lighter gas lets you either use more pressure while staying under the 1500 gram limit, or have less dead weight for a given bottle/propellant quantity (whichever way you want to look at it).

2) Non-ideal gasses have different compressability. Not my field, so I can't calculate it, but it's significant enough that the rules forbid it for this reason. You have to use air.

Comment Re:From TFA: bit-exact or not? (Score 1) 174

Dithering isn't about adding noise either BTW.

"Dither is an intentionally applied form of noise used to randomize quantization error..." --

It's also unrelated to interpolation ("...a method of constructing new data points within the range of a discrete set of known data points..."). No new data points are generated - the monitor knows the exact RGB values it wants to display; instead, it's about doing the best job presenting them within the limits of the hardware.

Regardless, your original point is still correct: 6-bit panels do make meaningful use of 8-bit input. Throwing away two bits per channel will visibly degrade an image.

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