Now here’s a science story you don’t hear every day. Simple scotch tape pulled off it’s reel in a vacuum makes x-rays powerful enough to image this finger.
NEW YORK -AP- Just two weeks after a Nobel Prize highlighted theoretical work on subatomic particles, physicists are announcing a startling discovery about a much more familiar form of matter: Scotch tape.
It turns out that if you peel the popular adhesive tape off its roll in a vacuum chamber, it emits X-rays. The researchers even made an X-ray image of one of their fingers.
Who knew? Actually, more than 50 years ago, some Russian scientists reported evidence of X-rays from peeling sticky tape off glass. But the new work demonstrates that you can get a lot of X-rays, a study co-author says.
“We were very surprised,” said Juan Escobar. “The power you could get from just peeling tape was enormous.”
Escobar, a graduate student at the University of California, Los Angeles, reports the work with UCLA colleagues in Thursday’s issue of the journal Nature.
He suggests that with some refinements, the process might be harnessed for making inexpensive X-ray machines for paramedics or for places where electricity is expensive or hard to get. After all, you could peel tape or do something similar in such machines with just human power, like cranking.
more here on MSNBC
Here is how it works:
The core theory is something called “triboluminescence,” which occurs when two contacting surfaces move relative to each other. It’s the same effect that causes “sparks” to fly when you chew wintergreen-flavored Lifesavers in the dark.
As the tape peels, the sticky acrylic adhesive, on the back of the tape, becomes positively charged, while the polyethylene roll becomes negatively charged. It’s not unlike a Van de Graff generator or a thunderstorm that shoots sprites out the top, It’s basically a small linear accelerator.
At a reduced atmospheric pressure, the mechanical act of pulling apart the two surfaces causes electric fields to build up that then trigger discharges of energy.
This accelerates electrons on the adhesive to very high speeds and when they whack into the positively-charged tape roll, X-rays result. The pulses last for a billionth of a second, with an intensity of about 100 milliwatts.
But ya know, with all that dangerous radiation, I expect we’ll see this TV news tease soon: “Shocking news from the world of science tonight… an everyday household item produces radiation that could cause cancer. We’ll tell you what it is at 11.“