In ancient times purple and blue dyes derived from snails were so rare and sought after that they were literally worth their weight in gold. These precious dyes colored the robes of the kings and princes of Media, Babylon, Egypt, Greece and Rome. To wear them was to be identified with royalty. This is the "Biblical Blue" color (techelet) being worn again by Jews to fulfil the mitzva of "And they shall place upon the tsitsit of each corner a thread of tekhelet" (Bamidbar 15:38).
These photos were taken at a recent presentation by Rabbi Navon using available light, as the use of flash would have been disturbing to everyone. Included are photos showing the actual chemical production of techelet from the snail extract. The last photo shows the color effect of using a fast shutter speed under fluorescent lighting.
Rabbi Mois Navon, an engineer and rabbi, has modeled himself on the principle of "Torah U'Madda" based on the philosophy of R. Soloveitchik as articulated by R. Lamm: Torah, faith, religious learning on one side and Madda, science, worldly knowledge on the other, together offer us a more over-arching and truer vision than either one set alone.
His writings can be accessed at http://www.divreinavon.com