"About making a magic flashlight?" His father was almost sarcastic, which revealed the extent of his exhaustion, Ken thought. He was never like that.
"What I'm trying to say is that there are other ways to precipitate colloids. We haven't even given any thought to them. Colloids can be precipitated by heat, by pressure, by vibration. Maybe a dozen other ways that I don't know anything about.
"Maybe some kind of physical means, rather than chemical, is the answer to our problem. Why don't we let Pasadena and the other labs go on with the chemical approach but let us do some work on possible physical means?"
Professor Maddox sat very still. His glance passed from Ken to Professor Larsen. The latter nodded. "I think we have indeed been foolish in ignoring this possibility up to now. I wonder if Ken hasn't got a very good thought there."
"Have you anything specific to suggest?" Ken's father asked.
"Well, I've been wondering about supersonic methods. I know that a supersonic beam can be used for coagulation and precipitation."
"It would depend on the size of the colloidal particles, and on the frequency of the wave, wouldn't it? Perhaps we could find a frequency that would precipitate the dust, but I wonder if we wouldn't have the same problem as with mechanical treatment of the Earth's atmosphere. Even if we succeeded on a laboratory scale, how could it be applied on a practical, worldwide scale?"
"I don't know," said Ken. "It may not work out, but I think it's worth trying."
"Yes, I agree. I don't think we'll give up the chemical research, but a group of you can begin work on this supersonic approach tomorrow."
The losses of food at the warehouse were enormous. Less than 5 percent of the contents could be removed in usable form. Most of the canned goods had burst from internal pressure. Grain and other dried products were burned, for the most part. The food supply of the community was now reduced to six-tenths of what it had been.