Science Update - Lasers for Train Tracks and Super Dishcloths

The Naked Scientists spoke to Chelsea Wald and Bob Hirshon from AAAS, the science society
08 October 2006

Interview with 

Chelsea Wald and Bob Hirshon from AAAS, the science society


Phil - We're now going to head over the Atlantic for some Stateside science. This week Bob and Chelsea reveal how lasers are being used to spot cracks in train tracks, and how a new kind of super dishcloth could see the death of deadly bacteria.

Bob - This week on Science Update, we'll talk about a new way to use lasers to keep trains on track. But first, Chelsea has this report about the latest advance in identifying biohazards.

Chelsea - Yes, a new technology could soon move biohazard detection out of the lab and into hospitals, food preparation facilities, and crime scenes. Cornell University fibre scientist Margaret Frey and her colleagues created a special fabric that anyone could wipe over a surface. The fabric has special sites that can hold antibodies to just about any biohazard, including salmonella, strep bacteria, and anthrax.

Margaret - So basically as long as there's an antibody available or some kind of biorecognition agent available, we can attach that onto the fabric, and then the fabric will collect that specific thing.

Chelsea - They're now working on ways to make the fabric change colour when the hazard's detected, so people will know immediately. Right now, the wipe must be put in a developer before it gives results.

Margaret - The goal is to have this super-simple and super - instant.

Chelsea - And so far, they can only collect one biohazard at a time, but they ultimately hope to collect hundreds at once, making it a powerful tool against all sorts of contamination.

Bob - Thanks, Chelsea. This tapping may sound like an old-fashioned news ticker, but it's actually a state-of-the-art laser system for inspecting train tracks. Structural engineer Francesco Lanza di Scalea of the University of California at San Diego is leading the development team. The system uses a trailer-like vehicle that glides along the track at up to 70 miles per hour, tapping the track with laser pulses at one-foot intervals.

Francesco - And this tapping is like a virtual hammer. Just like if you were to hammer on a rail, you'd hear a sound going through.

Bob - And distortions in that sound, specifically in the ultrasonic range, can reveal dangerous internal cracks that current technologies often miss. Repairing those cracks early could save millions of dollars and prevent derailments.

Chelsea - Thanks, Bob. That's it for this week. Next time we'll talk about the family tree of venomous fishes. Until then, I'm Chelsea Wald.

Bob - And I'm Bob Hirshon, for AAAS, The Science Society. Back to you, Naked Scientists.

Phil - Thanks guys. If you want to hear more from the Science Update crew, then you can go to their website at


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