Depends on the concentration and distance. It has a 33yr half life. So every 33yrs half of its mass decayed from the previous 33yr. As a thumb rule we say 5 half lives is enough to completely decay away.

Exposure is an inverse square law. So as you move away the exposure reduces exponentially.

Geiger-Mueller detectors work on the photoelectric effect. Point source radiation is an inverse square law. You wouldn't detect this stuff even a few miles away. Reactors hardly release any isotopes. It's the thermals that show up on satellites

All too aware of Cobalt -60. Iron 59 will undergo neutron proton reaction and become cobalt 60. It's the most common isotope of concern in reactor compartments. It has a long half life but it's decay produces a gamma of 7 MeV (mega electron volts).

If this is really source material for X-ray equipment, then why wasn't it well marked and locked in a relatively difficult container requiring a blow torch to cut through?

password recovery on cisco routers is a relatively simple process involving only a few minutes of outage. I should find it hard to believe the city of SF was using any other brand. That would be like buying everything made in china and complain that american laborers are out of work... oh wait, we do that.

given that this is slashdot and not linkedIN or MyTwitFace I would take that as a given

i would have empathized with her, but according to the article it was their complete apathy and bragging that they drove her to suicide, as if it was some achievement, that brought everything to light. Had it been a complete wakup call for them that they indirectly caused someone's death (defined as 'probable cause' for criminal charges) and they were now going through their own depression, I think you probably would be reading a different story with different comments in the threads.

this used to be the solution that worked well for millennia. Now the anti-violence zero-tolerance groups have squashed school fights to such a degree that this other problem is now unchecked. I would rather my child get suspended and send another kid home with a broken nose or limb than internalize the problem over and over until they snap, either internally (suicide) or externally (columbine).

perhaps not courageous, but I agree it goes against every animal instinct. There are some cases, possibly many arguably, that someone who succeeds in suicide didnt do it by overcoming this interlock. Its that this interlock simply wasnt there at the time they succeeded. Perhaps dispair, or medication. Seriously, you could take a hand full of sleeping pills and then go lap swimming in a pool. Theres a pretty good chance you wont be able to back out of that one, the medication wont let the interlock work.

12 year olds are not mature adults. they do not reason the same as we do. I know its been a long time since some of us were 12, some more than others; but accurately predicting the consequences of ones actions is not something they do very well. I have a 10yr old daughter and I am constantly amazed and some of the things she does as if she has no foresight at all.. then I realize; she doesn't. This situation and many like it are evolving because we are already trying to force adult situations and adult responsibilities on non-adults. 25yrs ago kids would solve this on the playground and it would get chalked up to 'kids being kids' and 'establishing a pecking order'. Now there is suspension and explusion for something humans have been doing for over 10k years. In this vacuum an even more sadistic and tormenting behavior has evolved in its place.

agreed, people tend to assign adult thinking processes to a child... we arent fully cognitive until we reach 25 and even then some still arent. I agree completely with seeking an escape from what may have felt like total despair. I only wish she had enrolled in some martial arts classes and kicked the shit out of those picking on her... worse case scenario she gets labeled 'violent' for a few years until she 'outgrows' it. In the meantime people will back the hell off.

I have to agree... to attempt to suppress bullying though policy does not resolve the issues and it doesn't prepare someone for more subtle bullying people can face when they become an adult. I think the biggest problem is they cracked down on fighting so severely its allowed bullying to grow out of control. Previously the check-and-balance to bullying was that you might get the shit beat out of you when you push someone too far. That teaches the victim to stand up for himself, it teachers the aggressor that you cant just go around and mistreat people and expect zero consequences. So now a child that bullied people their whole life pushes someone so far that they snap so severely that they shoot the bully or worse.. thats more or less columbine in a nutshell.

much less immigration (some at force) in these countries. However even with the amount you do have, this 'diversity' is starting to catch up. Look whats happening with the rioting from the radical muslim groups in france and norway. Murdering a cartoonist, not for sleeping with their wife, but for drawing... wait for it.. a cartoon.

EDUCATION or lack thereof is one of the largest precursors to violent crime. We have an over-abundance of people who fucked off in school and have no future. Their parents didnt require the school system be anything more than free daycare. Given the climate of all the violent crimes in the USA, a startlingly high percentage of them are committed by those you wonder have enough brain cells to even breath every day.

probably about as often as abortion is used to terminate pregnancy to spare the life of the mother or because the mother was a victim of rape and/or incest when compared to it being used as a lazy person's birth control.

There are those that make a case for banning every form and reason for abortion as well. Ironically these aren't the same groups despite being nearly identical in cause and effect analysis. Some of the most anti-gun people will insist that banning guns will eliminate violent crimes entirely yet argue that if you ban all abortion people will still find unsafer venues to have them. Yet the same argument applies that 'if you outlaw guns, only outlaws will have them' holds true. I have always wondered how badly personal bias gets in the way of logic and reasoning.

"They who can give up essential liberty to obtain a little temporary safety, deserve neither liberty nor safety."

- Benjamin Franklin

funny story about that. When I met my now-wife she had had a previous relationship with a member of her church. They were both volunteer youth group chaperones and he was a deacon of the church. Its the sort of thing every church going person pushes you to engage in, so she did. turns out he had a terrible habbit of buying whores with his free money. When she found out she dumped him like yesterdays news because. well, who wants to risk catching aids to say the least. His issues put her life at risk, directly. She took from that a lesson that everyone has issues, life is about finding someone with issues you're willing to live with and not the ones you are not. So despite that she is fairly religeous (not a bible thumper) and I am a Deist through and through, we've been married 13yrs and have 2 kids without much to do for problems. thats not saying we dont argue from time to time, but its always resolved and usually over stupid shit.