Q: I see advertisements for tritium-enhanced wristwatches and was wondering what, if any, health risks from radiation might be associated with those. Any information will be most helpful.— Michael Faragut, Atlanta
Gregory R. Choppin, R.O. Lawton Distinguished Professor of Chemistry replies:
The amount of tritium used in watches to provide the luminescence that enables the numbers to be seen (in the dark) is quite low and poses no health risk. Not only is the level of radioactivity used quite low, but also tritium emits a very low energy beta particle (electron) which is retained within the material and never reaches the wearer. The amount of tritium used in watches would have to be increased many thousand-fold before there would be a level of even minimal concern in terms of a health hazard.
Q: I have recently been intrigued with news stories about new evidence supporting theories that life on Mars did in fact exist ages ago. I believe research at FSU was implicated in this. What's the story here?— Kelly Marie Caither, Dayton, Tennessee
Imre Friedmann, R.O. Lawton Distinguished Professor of Biological Science replies
In the past few months, three independent research groups published evidence in prestigious peer-reviewed journals indicating the presence of fossil bacteria in the Martian meteorite ALH84001. The last paper was the paper of my group published in the Proceedings of National Academy of Sciences. Two days before it was printed, NASA issued a press release which was widely picked up by the media.
The release stated, matter of faculty, that we described in our publication chains of magnetite crystals in the Martian meteorite ALH84001 and that these are fossil remnants of magnetotactic bacteria. In a parallel press release NASA announced that another research group from the Johnson Space Center reported that the structure of magnetite crystals is similar to those in magnetotactic bacteria now alive on Earth but different from inorganically produced magnetite. Thus, our finding of magnetite crystal chains was the "missing link" in the chain of evidence proving that what we have in the meteorite is really fossil bacteria.
In the U.S. and U.K., but not in other countries, the NASA report was accompanied by negative comments by fellow scientists before any of them would have had a chance to read our paper and see the evidence. Both the U.S. and the U.K. have active Mars programs and the colleagues who expressed these opinions are our competitors. The negative comments were not withdrawn even after the publications became available. To date, no one has refuted our results with concrete arguments, nor has anyone faulted our methods, observations or conclusions. You can draw your own conclusion. The debate is not yet over.
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