Do crystals have special powers? Could a super-bright light cause blindness?
A couple questions: (1) Is there any scientific evidence that crystals emit power or store energy? (2) Is it possible to create a comic book-type flashlight so bright the briefest exposure would cause permanent blindness?
(1) Sure, crystals emit power — the power to enrich gemshop owners beyond their wildest dreams. The wholesale price of quartz crystals, the kind most often mentioned as having mystic properties, has increased 1,000 percent since the crystal craze began. Claims of healing powers, however, are spurious and are a result largely of a misunderstanding of quartz's technical properties by addle-brained New Agers.
Quartz, also known as silicon dioxide or silica, is the earth's most abundant mineral, most often seen in the form of sand. Quartz crystals can be created in hot water under pressure, a process that may be readily duplicated in the lab. Though not as iridescent (or as hard) as diamonds, quartz crystals are undeniably pretty, and that plus their large size and easy availability has undoubtedly contributed to their popularity.
Quartz crystals are widely used in timepieces and radio tuners owing to two interesting properties: they don't expand much when heated, and they change shape slightly when subjected to an electric field, a phenomenon known as the piezoelectric effect. When the electric field in question is alternating, the crystal vibrates.
All crystals have a certain natural "pitch," or frequency of vibration, much as a glass of water has a characteristic tone when you tap it with a spoon. If you hook an alternating circuit to a crystal and tune the circuit's frequency to the crystal's natural frequency, the two will resonate. Thereafter the circuit will stay locked into the crystal's frequency through a process of mutual reinforcement. A crystal's pitch is determined by its size and shape, and since quartz expands only minimally when warm, quartz-tuned circuits are quite accurate.
Crystal buffs have used the fact that quartz crystals vibrate as the basis for a vast edifice of nonsense about "resonance," "harmonics," and "energy." The mildest claim is that crystals will "center your energies" and improve your life somehow, and if that's as far as you take it, using crystals is no worse than reading your horoscope or buying diet books. But a few extremists claim crystals can help cure cancer, AIDS, and other diseases. There is no scientific grounding for these claims, and anyone who uses crystals as a substitute for proven therapies is endangering his health and possibly his life.
(2) Certainly — in fact such a flashlight was first demonstrated in 1945. It's called an atom bomb. In his book Hiroshima John Hersey describes some victims: "There were about twenty men, and they were all in exactly the same nightmarish state: their faces were wholly burned, their eyesockets were hollow, the fluid from their melted eyes had run down their cheeks. (They must have had their faces upturned when the bomb went off; perhaps they were anti-aircraft personnel.)" The bomb emitted a vast amount of thermal (i.e., nonnuclear) radiation, a mixture of ultraviolet, visible, and infrared rays. The invisible infrared rays, which we perceive as heat, caused most of the damage. I suppose one could argue infrared doesn't really qualify as "light," in the colloquial sense, but the distinction hardly seems worth making.