These are all good questions. Some better questions are: Who developed the software that controllers the radiation output? Who tested it? Is the software under configuration control? Was it developed as tested as safety-critical software? To what standards? Was failure mode testing performed on the system?
I guess you’re right, there’s not a chance in hell.
Quality management has come a long way in the last 25 years.
The first time I went through one of those scanners, I had a scrap of paper in my front right pocket that I’d forgotten to take out. The attendant quickly asked me what I had in my front right pocket.
So, yeah, they can see pretty much everything.
Do they work all the time? Because metal detectors seem to be off sometimes. I accidently, really accidently, left a really big swiss army knife in a pocket and breezed right through. I discovered it right before getting on the plane. I just kept quiet about it but I could have probably dismantled a bit of the plane if I had been a bad guy. I assume if enough people do the same, some percentage of them will make it onto the plane with all manner of objects.
But then it is the size “some” people could hide up their ass anyway.
That is a big overstatement. There is a long history of overdoses from radiation therapy machines (anybody remember the Therac 25?) and recently there have been a lot of cases of overdoses during CT scans that were only being used for diagnostic purposes.
http://www.nytimes.com/2010/08/01/health/01radiation.html
I doubt that a properly designed backscatter screening machine will hurt anyone, but I can guarantee if the machines aren’t idiot proof they will hurt someone, because they are going to be operated by idiots.
According to this story, the scanners have kept over 130 “prohibited, illegal, or dangerous” items off planes this year. Probably the items were mostly harmless, but the article mentioned ceramic knives, which would have passed through a metal detector no problem.
Then again the article is from Fox News so it’s probably all lies, right? 
The problem is that prohibitted and illegal does not mean dangerous.
Yeah, my water bottle is prohibited, remember? And recall when they tried to say that old guy’s Medal of Honor was a weapon? Also prohibited, I guess.
And a “syringe filled with heroine”, which means we saved a superhero’s life, I guess. (And even if it were filled with heroin, I am unaware of any way to use narcotics to blow a plane out of the sky. I do not give a shit if the TSA catches your drugs.)
In the days when cigarette lighters were prohibited, I got several past them, along with a few small bottles of hand lotion. Hah! Take that, TSA.
Bad news, Gizmodo recently had a post about the TSAs in Orlando saving body scan images. Granted, the faces are obscured in the link but I’m sure in the originals they are clear. Either way, there they are, on the internet.
As to the OP, I recently “failed” a scan cause I had forgotten to take a lighter out of my pocket. The pat down didn’t really bother me but it was annoying since it slowed us down.
Yeah, that’s why I said the items were probably mostly harmless. I’m sure the TSA is ever so proud of all the small bags of weed and 4 ounce shampoo bottles they found with their scanners. But out of the 130 items there were probably a couple of items that posed an actual danger.
But it can see the dangling fuse…
That may be what wiki and the TSA are saying, but that’s not what some people in the medical science community are saying:
Biochemist says ‘naked’ X-ray scanner may be unsafe
Frankly, I trust scientists over the government.
I’ll assert that not a single item posed any real danger. Why? Because we didn’t hear about it.
Inter-divisional politics in the government is all about the size of your budget, and the best way to keep your budget fat and happy is to show that what you’ve already spent money on is effective. The best way to do THAT is to get your successes in the news media. Show that your nifty little budget entry has caught an actual bomber and you’d have press for weeks.
BTW, am I the only person who finds the Underwear bomber story amusing?
Frankly, these “scientists” are full of shit. People are irradiated daily through natural means. These machines output the amount of radiation associated with 4 minutes of flight time.
How are you getting this number?
And I’m still trying to figure out what you mean by putting scientist in quotes. Are you saying that this guyisn’t really a scientist?
Those particular photos are a hoax.
I read the full body scanners can not pick up plastics, liquids or chemicals. So how are they better than a metal detector?
Answer: they make passengers feel safer. That is what they are after.
Yes but if millions of people go through thousands of machines, over time the chance of a screw-up of some sort is pretty likely, in my opinion.