FM Crystal Radio

Actually, you already have one with the slope detector - the thing is, FM broadcast is 88-108 MHz, and AM broadcast is 530-1650 Khz, so you'd have to change your tuned circuit to change from AM to FM, just so there'll be signals to receive.

But go ahead and build it anyway - that's a terrific way to learn about this kind of stuff. :-)

Have Fun! Rich

Of course, there was a wave when "crystal radios" were common for VHF. But they were specific to the aircraft band, 108 to 136MHz, since of course that band uses AM. I remember one in Elementary Electronics in 1971 or 72 where it built on flexible circuit board, so you could wear it without anyone noticing. I thought that was novel, but I've seen similar circuits in older magazines.

Michael

Thanks, Bob. I read the page. It gets the idea across pretty well and accurately enough, though it is shy on quotes. Einstein had a personal meaning for 'religious,' quite different from the use most carry for it.

I do imagine that Einstein may have felt that the shared positive aspects of science and of religion might be a: "free and responsible development of the individual, so that he may place his powers freely and gladly in the service of all mankind." And perhaps on that point Eintein placed his hopes.

Probably the best part of one of his monologues on science and religion is this one. I'll quote it more fully because it covers this idea of a personal god and provides enough context to get the main idea he was trying to discuss.

"The main source of the present-day conflicts between the spheres of religion and of science lies in this concept of a personal God. It is the aim of science to establish general rules which determine the reciprocal connection of objects and events in time and space. For these rules, or laws of nature, absolutely general validity is required -- not proven. It is mainly a program, and faith in the possibility of its accomplishment in principle is only founded on partial successes. But hardly anyone could be found who would deny these partial successes and ascribe them to human self-deception. The fact that on the basis of such laws we are able to predict the temporal behavior of phenomena in certain domains with great precision and certainty is deeply embedded in the consciousness of the modern man, even though he may have grasped very little of the contents of those laws. He need only consider that planetary courses within the solar system may be calculated in advance with great exactitude on the basis of a limited number of simple laws. In a similar way, though not with the same precision, it is possible to calculate in advance the mode of operation of an electric motor, a transmission system, or of a wireless apparatus, even when dealing with a novel development.

"To be sure, when the number of factors coming into play in a phenomenological complex is too large the scientific method in most cases fails us. One need only think of the weather, in which case prediction even for a few days ahead is impossible. Nevertheless no one doubts that we are confronted with a causal connection whose causal components are in the main known to us. Occurrences in this domain are beyond the reach of exact prediction because of the variety of factors in operation, not because of any lack of order in nature.

"We have penetrated far less deeply in the regularities obtaining within the realm of living things, but deeply enough nevertheless to sense at least the rule of fixed necessity. One need only think of the systematic order in heredity, and in the effect of poisons, as for instance alcohol, on the behavior of organic beings. What is still lacking here is a grasp of connections of profound generality, but not a knowledge of order in itself.

"The more a man is imbued with the ordered regularity of all events the firmer becomes his conviction that there is no room left by the side of this ordered regularity for causes of a different nature. For him neither the rule of human nor the rule of divine will exist as an independent cause of natural events. To be sure, the doctrine of a personal God interfering with natural events could never be refuted, in the real sense, by science, for this doctrine can always take refuge in those domains in which scientific knowledge has not yet been able to set foot.

"But I am persuaded that such behavior on the part of representatives of religion would not only be unworthy but also fatal. For a doctrine which is able to maintain itself not in the clear light but only in the dark, will of necessity lose its effect on mankind, with incalculable harm to human progress. In their struggle for the ethical good, teachers of religion must have the stature to give up the doctrine of a personal God, that is, give up that source of fear and hope which in the past placed such vase power in the hands of priests. In their labors they will have to avail themselves of those forces which are capable of cultivating the Good, the True, and the Beautiful in humanity itself. This is, to be sure, a more difficult but an incomparably more worth task. After religious teachers accomplish the refining process indicated they will surely recognize with joy that true religion has been ennobled and made more profound by scientific knowledge."

But to be clear, Einstein also pointed out the anthropomorphic derivations of religious ritual and response to mystery, as well as the overriding role science plays in improving the quality of it, in a single sentence: ".. so it seems to me that science not only purifies the religious impulse of the dross of its anthropomorphism but also contributes to a religious spiritualization of our understanding of life."

Most folks, using the word 'religion' do not often mean it the way Einstein did -- neither by way of his earlier nor later writings. To understand his responses and his evolution, one must actually carefully read what he wrote and not just my quotes or anyone else's. He writes enough, though, that most of us reading all of them will arrive at a similar understanding. Certainly, those with much science training, anyway. I'm an atheist, didn't read Einstein on this subject until my own mid-life, and I find his comments completely congruent with my own long-developed views. That doesn't make him an atheist, but he certainly isn't 'religious' in the usual meaning.

Jon