Ask MetaFilter questions tagged with detector

Stress Detector

philosophistry — Fri, 16 Oct 2009 16:32:48 -0800

Is there a device that can automatically observe your stress levels in real-time? A research scientist mentioned she knew of another research scientist who had a device like this. As she said, "It reminds [me] of a researcher who has a sensor on her computer, which can tell if you're stressed as you're typing away at work." When I followed up with more questions, she couldn't recall details.

I also vaguely remember this being possible. Maybe through a webcam that can tell your facial expressions. Anybody have any leads?

As a half-measure, I bought a heart rate monitor which is effective at telling you when your blood is boiling. While you may not need a monitor to tell you this, I believe in the saying, "if you can measure it, you can control it."

Finding a missing wedding ring in a field

Kwine — Tue, 11 Aug 2009 18:47:25 -0800

I lost my wedding ring playing soccer today. Help me maximize my chance of getting it back with a metal detector, or provide another better idea. I am a person of extreme stupidity, and volunteered to play goal keeper without taking off my wedding ring. I noticed it was missing right after I made a save on a hard shot; I'm pretty sure that knocked it off since I'm sort of OCD about messing with the ring.

Both teams searched the area at halftime and after the game with no luck-which makes me think that I need to broaden the search area. I notified the field manager, and left my name and number with her; she said they would hold off mowing that field tomorrow (I am on Eastern Time USA)

I am going to buy a metal detector in the morning and head out there, but I know nothing about them. How do I use it? Does it matter how expensive it is or will a cheapo one work just as well? Do you have another idea for helping me get it back?

How invisible is he really?

pokeedog — Sun, 23 Nov 2008 16:43:14 -0800

Would a invisible man set off a motion detector? Would it depend on the type of invisible he is? So if the invisible man was visibly invisible, but not infrared invisble? Or he was visibly and infrared invisible but not something else?

Best Bat Detector

roofus — Wed, 01 Aug 2007 03:24:12 -0800

I'd like to listen to the bats in my local park. What kind of detector should I get? I have rudimentary soldering skills, but was impressed by the home made bat detector featured in Make. Should I go for that entirely DIY solution, order a pre-compiled kit, or just pay up for an assembled detector? I don't really know what advanced features I'm looking for, but would like to be able to distinguish Pipistrelles, noctules and Daubenton's bats, and would ideally want a detector with a regular headphone jack.

Recover my wedding ring?

escher — Tue, 13 Mar 2007 00:58:14 -0800

The mountain ate my wedding ring, help me find it! I recently got married on October 15th, and got myself a shiny new tungsten ring to wear. The ring is fairly large at 8mm diameter, and size 11.

Last weekend while I was backpacking, I lost the ring. I'm pretty sure I lost it when I was sliding down the side of a large mud hill. This hill is about 60 feet high and has a fairly steep edge. It's a "mud hill" which is made of very loose dirt that crumbles when you step on it. I was able to just slide down on my feet and used my (left) hand to balance myself. As I slid down the hill, I brought a lot of loose dirt down with me in a sort of mini dirt avalanche. I'm pretty sure that my ring is in that dirt somewhere. It could be a couple inches deep, it could be on top, it could be up to maybe a foot deep. The dirt also has lots of calcite type rocks in it that glisten in the sun, so the "find the shiny object in the hill" strategy doesn't work.

So, i could go and buy another ring, yes, but what sounds much more fun is to go back to the hill and find my original. So, questions:

- How should i go about finding my ring?
- The first thing i think of is a metal detector. Can i rent a metal detector anywhere? I'd rather not have to buy one for a one time use.
- can a metal detector find tungsten? They say they can find "metals" like gold and silver, and I assume this includes tungsten but I'm not sure
- any other ideas on getting the ring back?

Take a metal detector on an airliner?

pax digita — Thu, 13 Apr 2006 05:42:07 -0800

Can a US airline passenger take a metal detector along on an airline flight? [m/i] So I work with a guy who likes to look for old coins and stuff with a metal detector. He's getting ready to fly down to San Juan, Puerto Rico, and wants to take his metal detector along so he can scout around on the beach to see if there's anything interesting.

He tells me he can't get a straight answer from the travel agency, the airline, or the TSA about whether it's OK to take his metal detector, and if so, whether it has to be checked baggage. When he tried TSA, he got generic non-information. The airline referred him to TSA for anything not covered in the standard document, which doesn't mention such items at all.

Anybody know anything definitive?

Blowing air from airport security.

Sreiny — Sun, 05 Feb 2006 21:48:58 -0800

I went through airport security today, and had to go through a large apparatus that blew bursts of air at me from about 30 little air jets. What was that? What does it do? What were they looking for? This was at the Indianapolis International Airport for those who were wondering. I'd never seen it before. It was like an oversized metal detector that you walk into, stand in the middle and then are shot with air. The air nozzles are from the floor to about six feet high and shoot air progressively down your body. Interesting contraption.