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Comment Re: Israel abuses human rights (Score 2) 278

"Peace is not part of their vocabulary. Only Hate Israel, Destroy Israel."

And this is an example of the harm done by generalizations and pre-judging people based on the group they a part of.

In 2005, a Palestinian 12-year old boy was shot by an Israeli soldier who mistook his toy gun for a real weapon. Despite the best efforts of the Israeli physicians, he was declared brain dead a few days later. His parents--who had just lost their son to an Israeli soldier's mistake--decided against riot and anger; instead, they donated all of the boy's organs. The recipients were Israelis--with the parents' blessing.

"I donâ(TM)t mind seeing the organs in an Israeli or a Palestinian. In our religion, God allows us to give organs to another person and it doesnâ(TM)t matter who the person is,â(TM) said Jamal al-Khatib, the boyâ(TM)s father, who added that he hoped the donations would send a message of peace to Israelis and Palestinians."

Comment Re:Android Version Only? (Score 1) 93

Thanks, both you and orev.

I expect that, in the (vast?) majority of cases, RunKeeper is doing this without the user's knowledge or permission; I inferred from the articles that it may be doing that by somehow overriding the user's tracking settings in Android. (But, that was an inference only.) I didn't think there was a way to do that in iOS, so glad to have my understanding affirmed.

Comment Meteors (Score 3, Interesting) 29

I was surprised at the number of (what appear to be) meteor craters; I knew that Pluto is in the Kuiper belt, but I always had the impression that the density of that belt was really low. OTOH, Pluto has been wandering around that region for billions of years, so I guess that adds up over time. Very cool!!

Plaudits to the New Horizons team! Yay science!

Comment Re:Bullets don't knock people down (Score 4, Insightful) 369

(Trigger warning: Physics teacher here!)

Actually, momentum is NOT conserved for the *shooter*. He is bracing himself against something (his feet on the ground, usually), so there is an external force acting on him. Thus, this particular argument fails.

For the victim, if he is shot unawares (so he doesn't brace himself), then conservation of momentum *does* apply. I calculate that he will experience a force to his chest of about 35 newtons (~8 pounds). That's not much, and won't accelerate him much.

However--it may well knock him down. The reason is, the force to his chest will cause a torque on him, which will cause him to rotate down to the ground. If we assume he rotates about his feet, and treat him as a solid cylinder (reasonable approximation) then I get an angular acceleration of about 0.4 radians per second per second (22 degrees per second per second).

That only lasts while the bullet is in contact with him, of course; after that, the victim has a gravitational torque on him, with a corresponding angular acceleration (I estimate) of 9 rad/s/s.

If someone wants to check my work, I'll supply the numbers and things I used. I might well have made a mistake or missed something.

Comment Ikea Bekant (Score 2) 340

I got the Ikea Bekant; it's great, solidly built, and less than $500US. I used a felt pen on the legs to mark my optimum sitting and standing heights so that I don't have to take five minutes fine-tuning the height every time I change heights (which would have guaranteed that I would never change the height!).

Sometimes I change multiple times a week, sometimes multiple times a day. It's great.

Comment DIY Speakers (Score 4, Interesting) 249

I obsess, but don't spend $$$$ on equipment. As someone posted above, once you have equipment that's better than "on sale at Walmar!", most people won't hear any difference between amplifiers, or CD players, or the audio from Blu-ray players. (You can in a side-by-side A/B test, but what fraction of people do that in their homes?)

My obsession, and my money, went to making my listening room/home theater as acoustically perfect as the floorplan of my house would allow. I put up walls to prevent most standing waves, acoustically treated the walls and ceiling (all in consultation with a professional acoustician; I didn't just stick stuff up on the walls randomly), and positioning my speakers as optimally as possible. Made a WORLD of difference in the sound quality.

And, the other really great investment I made was building my own speakers. Designs exists on the Intertubes (e.g., and the enormous fun and satisfaction of building them yourself cannot be overexpressed. Plus--with all due modesty--my speakers sound as good as speakers that cost 10-50 times what I spent (not including tools, heh). Friends that hear them are astonished that they are DIY speakers.

(N.B.: I am not taking credit for the designs; I have neither the knowledge nor the skills to design quality speakers. I simply implemented the designs and plans I found. There are some seriously smart people out on the web.)

Submission + - Every Time You Fly, You Trash The Planet — And There's No Easy Fix (

jIyajbe writes: Christie Awchwanden of writes "When the latest international Climate Conference wrapped up in Lima, Peru, last month, delegates boarded their flights home without much official discussion of how the planes that shuttled them to the meeting had altered the climate. Aircraft currently contribute about 2.5 percent of global carbon dioxide emissions...if the aviation industry were a country, it would be one of the world’s top 10 emitters of CO2. And its emissions are projected to grow between two and four times by 2050."

Beyond just volume of emissions:

Planes don’t just release carbon dioxide, they also emit nitrogen oxides, sulphur oxides and black carbon, as well as water vapor that can form heat-trapping clouds...These emissions take place in the upper troposphere, where their effects are magnified. When this so-called radiative forcing effect is taken into account, aviation emissions produce about 2.7 times the warming effects of CO2 alone...

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