Sorry, but your answers are incorrect - the 2 GHz refers to a clock speed at which the computer is running, not electromagnetic waves. If you have a watch that ticks of seconds, you can say the clock speed is 60 Hz (60 cycles/second) - that happens also to be the frequency of the AC voltage at...
No, the resonant frequency is about 10 GHz @ 10 C; there is a relationship and given by Debye 1929 Polar Molecules, Chemical Catalogue New York. You can see a graph in Table 2.7 in Metaxas: " Foundations of Electroheat: A Unified Approach" published by John Wiley
Yes - the metal rods have to have good electrical conductivity and this can vary in different metals. Interestingly, carbon particles also arc to each other
The gap is important because you need a high electrical potential - large enough to cause the voltage to "jump the gap" and that is 33 kv/cm - that's a very large voltage - if the gap is larger, the voltage has to be proportionally larger; if the gap is smaller the voltage is proportionally...
Sparks (arcs) are caused by electrical breakdown (ionization) of the air. That take a field strength of about 33 Kvolts/cm in air at standard temperature & pressure. This threshold reduces as pressure decreases, which is why microwave energy has never been successfully used for freeze-drying...
Interesting question and I can only speculate on the answer. Note that there is little difference between the emissivity of ice & water; this is possibly due to there always being a monomolecular layer of water on the surface of ice until the temperature drops to minus 100C or less (that's why...
Remember that water heats because it is an electrical dipole and is constantly vibrating. This vibration is affected by the presence of the rapidly oscillating microwave (electrical) field and this causes the heating. However, ice is frozen water in which water molecules are caught in a...
Your comment "In a microwave oven, the electromagnetic waves are tuned to coincide with the resonant frequency of water molecules" is incorrect. The resonant frequency of water at room temperature is approximately 22 GHz, while the microwave oven frequency is 2.45 GHz. This results in two...
Pacemakers were never a problem - that's a myth, and even if true, the early ones were improperly shielded. They don't exist any more. With early pacemakers, there were recorded incidents due to lawnmower & automobile engines, elevators switches and some other things - but never a microwave...
The fact that it will probably never happen is true - after all, when people are terrified that cell phones could be causing brain cancer, they will never accept microwave-people-heaters. My point was simply that the idea is not so far fetched, and that many people are unjustifiably worried...
In 1980. the concept of a "people heater" was put forth by Professor R.V. Pound of Harvard. His suggestion was to heat people rather than an entire room as a means of conserving energy. That way, when a person went from one room to another the microwave energy would cease in the first room and...
No, I believe you don't understand the wavelength - if it is 10 cm in air, that's :the "free space wavelength". But the wavelength thru the stones is the "material wavelength" which is
material wavelength = free space wavelength/ Square root of the dielectric constant,
or, for stones...
John
Concrete has a loss factor of approximately 12 at the frequencies that you mention. That means that the wavelength that 1 GHz will be approximately 9 cm, and a 2.45 GHz approximately 3.5 cm. Penetration depths will be somewhat smaller than that. So it is likely that there will be very...