The DHS's latest airport security device: Terahertz laser scanners

Re:The DHS's latest airport security device: Terahertz laser... by droithomme on Wednesday July 11, 2012 @08:42AM (#4228952)

If these devices worked to accurately identify unknown materials from 50 feet away, they would already be used in thousands of labs and we'd know empirically how well they work, whether non-scientists can use them as accurately as scientists, what the false positive rate is, etc. If more accurate than a traditional lab spectrometer they would already be used widely. If less accurate, we don't need them to be used to get probable cause for "bomb" searches that "just happen" to turn up things like too much cash or a bit of pot. Even worse, we don't need their results as "evidence" that drug or bomb "residue" was found. Already we see many people arrested for "possession of meth precursors" because they have aluminum foil, plastic sandwich bags and brake fluid in their house. In many cases it is about coming up with a plausible reason for arresting people these days rather than actually holding criminals who cause trouble (such as those on wall street) accountable.

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Re:The DHS's latest airport security device: Terahertz laser... by darklajid on Wednesday July 11, 2012 @09:13AM (#4229059)

Not sure if you did that intentionally (to make the claim even more questionable), but the article says "50 meters", not "50 feet". That's more than 3 times the distance.

Silent downvotes, how lovely. Why? For reference: https://dl.dropbox.com/u/1194203/Terahertz.png

Unless they geo-locate me in Europe and s/feet/meter/ (how stupid would that be?) I fail to understand what the silent criticism is for.

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Re:The DHS's latest airport security device: Terahertz laser... by droithomme on Wednesday July 11, 2012 @05:35PM (#4231634)

Thanks for the correction. Yeah, 50ft or 50m both are pretty amazing claims. I want to see some third party reviews of how well this works with random substances and how often oregano becomes pot and cash is ID'd as cocaine residue, blood, nitroglycerin, or other random things. No references are provided to any of this though, yet it sounds like they ready to sell and deploy this without any public review or consent.

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Re:The DHS's latest airport security device: Terahertz laser... by pvnick on Wednesday July 11, 2012 @10:43AM (#4229400)

Your comment comes off as critical and hostile, whereas I'm sure his mistake was just that - a mistake.

That's why you're getting downvoted. This isn't reddit.

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Re:The DHS's latest airport security device: Terahertz laser... by darklajid on Wednesday July 11, 2012 @04:07PM (#4231173)

1) 'Comes off as' is more often than not wrong in a text based conversation where you don't know the other party. I didn't intend to nitpick, I wanted to emphasize 50m. 15m would be impressive, but 50m is just so much more unbelievable.

2) 'This isn't reddit' is a bullshit appendix for any comment. Thank you for helping me understand that the comment might be misunderstood. Let me return the favor by saying that your last sentence is (objective) useless or harmful, please avoid it.

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Re:The DHS's latest airport security device: Terahertz laser... by MichaelSalib on Wednesday July 11, 2012 @10:11AM (#4229240)

To be fair, there's actually a lot of interesting work happening with this technology, and it is fairly recent. There's a group at Tufts using these devices for ultra-cheap non-invasive real time brain scanning (it turns out that human skulls are mostly transparent to light at these frequencies). My spouse briefly worked with them.

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Re:The DHS's latest airport security device: Terahertz laser... by CWuestefeld on Wednesday July 11, 2012 @09:32AM (#4229122)

If these devices worked ..., they would already be used in thousands of labs

There's an old joke about economists: two economists are walking along the road, and see a $20 bill sitting on the ground. The first asks "are you going to pick that up?". The second responds "Nah. If it were real, somebody would have taken it already.".

That said, I mostly agree with your complaints. You should note, though, that SCOTUS precedent already addresses related concerns, saying that our homes are safe from prying by way of high-tech sensors that normal people don't possess.

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Re:The DHS's latest airport security device: Terahertz laser... by mattmanser on Wednesday July 11, 2012 @09:40AM (#4229143)

There's a reason that joke's about economists and not scientists.

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