Air Force Study Shows How to Boil Eyeballs with Lasers

Annalee Newitz — Fri, 02 May 2008 15:02:42 PDT

We may not be using lasers on the battlefield yet, but when we do we'll know exactly how to use them to make our enemies' eyeballs explode. And how to create heat-induced bubbles inside "biological substances" (i.e., bodies). A researcher funded by the Air Force to study laser safety has inadvertently also produced a lot of data on what makes them unsafe too. His paper is ominously titled "Laser Induced Shock Waves and Vaporization in Biological Systems and Material Science."

Physicist Bernard Gerstman, author of the paper, writes:

Damage by pulsed lasers to the retina or other tissues containing strongly absorbing particles may occur through biophysical mechanisms other than simple heating. Shockwaves and bubbles have been observed experimentally, and depending on pulse duration, may be the cause of retinal damage at threshold fluence levels. We performed detailed calculations on the shockwave and bubble generation expected from pulsed lasers. For a variety of different laser pulse durations and fluences, we tabulated the expected strength of the shockwave and size of the bubble that will be generated. We also explain how these results will change for absorbing particles with different physical properties such as absorption coefficient, bulk modulus, or thermal expansion coefficient. This enables the assessment of biological danger, and possible medical benefits, for lasers of a wide range of pulse durations and energies, incident on tissues with absorbing particles with a variety of thermomechanical characteristics.

Gerstman has been studying laser interaction with eyes for many years — his main interest is in safety. But to figure out what makes lasers harm human eyes, he of course had to figure out exactly when and how that harm would occur. As Danger Room's David Hambling observes:

His findings may later be used by others with less humane motives — such as anyone interested in the anti-personnel possibilities of high-energy laser pulses which cause 'explosive bubble formation' in human flesh.

Indeed. Image via Laserforce.

Laser-Induced Shockwaves and Vaporization in Biological Systems [PDF] via Danger Room

Race Through A Day-Glo Hot Wheels Playset

Kevin Kelly — Mon, 18 Feb 2008 13:30:10 PST

People who have seen the trailer for the live-action version of Speed Racer say it looks more like a video game than a movie. But what's wrong with that? If you can make a film feel like the eyeball-blasting you get from a game these days, then the marketing department, the toy department, the sequel department, and yes, even the video game department will fall over backwards trying to kiss you on the ass. So it's no surprise that Speed Racer is getting a video game for the Wii and the Nintendo DS (which unfortunately means that graphics are less than amazing), and you can check out the new images from it in the gallery below.

It'll leave your retinas in a bit of pain, but it's the only time we've ever seen anything come close to approximating the view from inside one of those Hot Wheels loop-de-loop courses we used to play with back in the day. Some of the lines in the trailer made us cringe a bit, and we'll be missing the ultraquick dialogue and the speed lines... but we're marginally starting to look forward to what these races look like both in the movie, and in the game. We just hope you can use all of the gadgets that the Mach 5 has to offer while you batter your opponents.

Take a first look at Speed Racer [Palgn]

io9: eyeballs

Air Force Study Shows How to Boil Eyeballs with Lasers

Race Through A Day-Glo Hot Wheels Playset