in my electric light. It was roughly round and strongly resembled a drum. So strongly did it resemble one that I automatically reached out and tapped it with my right forefinger."
He gulped down the rest of his drink and said, "It was a drum; or at least it was a structure that set up a vibration when tapped. As soon as I touched it, a dim rumble filled the room; a vague sound just at the threshold of hearing and all but subsonic. Indeed, as I was able to determine later on, the portion of the sound that was high enough in pitch to be heard was a tiny fraction of the whole. Almost all the sound expressed itself in mighty vibrations far too slow to affect the ear, though it shook the body itself. That unheard reverberation gave me the most unpleasantly uneasy feeling you could imagine.
"I had never encountered such a phenomenon before. The energy of my touch had been minute. How could it have been converted into such a mighty vibration? I have never managed to understand that completely. To be sure, there are powerful energy sources underground. There could be a way of tapping the heat of the magma, converting a small portion of it to sound. The initial tap could serve to liberate additional sound energy - a kind of sonic laser, or, if we substitute 'sound' for 'light' in the acronym, we can call it 'saser.'
I said austerely, "I've never heard of such a thing."
"No," said West with an unpleasant sneer, "I dare say you haven't. It is nothing anyone has heard of. Some combination of geologic arrangements has produced a natural saser. It is something that would not happen, by accident, more often than once in a million years, perhaps, and even then in only one spot on the planet. It may be the most unusual phenomenon on Earth."
"That's a great deal," I said, "to deduce from one tap of a forefinger."
"As a scientist, sir, I assure you I was not satisfied with a single tap of a forefinger. I proceeded to experiment. I tried harder taps and quickly realized that I could be seriously damaged by the reverberations in the enclosure. I set up a system whereby I could drop pebbles of various sizes on the saser by means of a makeshift long-distance apparatus while I was outside the cave. I discovered that the sound could be heard surprising distances outside the cave. Using a simple seismometer, I found that I could get distinct vibrations at distances of several miles. Eventually I dropped a series of pebbles one after the other and the effect was cumulative."
I said, "Was that the day when dim rumbles were heard all over the world?"
"Exactly," he said. "You are by no means as mentally deprived as you appear. The whole planet rang like a bell." "I've heard particularly strong earthquakes do that." "Yes, but this saser can produce a vibration more intense than that of any earthquake and can do so at particular wavelengths; at a wavelength, for instance, that can shake apart the contents of cells - the nucleic acids of the chromosomes, for instance."
I considered that, thoughtfully. "That would kill the cell."
"It certainly would. That may be what killed the dinosaurs."
"I've heard it was done by the collision of an asteroid with the Earth."
"Yes, but in order to have that done by ordinary collision, the asteroid postulated must be huge. Ten kilometers across. And one must suppose dust in the stratosphere, a three-year winter, and some way of explaining why some species died out and others didn't in a most illogical fashion. Suppose, instead, that it was a much smaller asteroid that struck a saser and that it disrupted cells with its sound vibration. Perhaps ninety percent of the cells in the world would be destroyed in a matter of minutes with no enormous effect on the planetary environment at all. Some species would manage to survive, some would not. It would be entirely a matter of the intimate details of comparative nucleic acid structure." "And that," I said, with a most unpleasant feeling that this fanatic was serious, "is the weapon the Lord has placed into your hands?"
"Exactly," he said. "I have worked out the exact wavelengths of sound produced by various manners of tapping the saser and I am trying now to determine which wavelength would specifically disrupt human nucleic acids."
"Why human?" I demanded.
"Why not human?" demanded he,