logajan@ns.UUCP (John Logajan x3118) (09/03/88)
We generally associate radio transmission with wave properties. But we
also know that such emissions have photonic-particle like properties.
The point I have trouble seeing is how to explain continuous frequency
change in terms of discrete photons. Frequency shifting is easy to
visualise from a waveform point of view -- but in a particle point of
view, isn't one forced to make the assumption that frequency shifting
can only occur in quantum steps -- that there is no such thing as a
continuously smooth frequency change.
Perhaps I should have used the term "discrete steps" rather than quantum
steps, since I didn't mean to imply that each step was constrained to be
any specific "leap" from the previous.
--
- John M. Logajan @ Network Systems; 7600 Boone Ave; Brooklyn Park, MN 55428 -
- {...rutgers!dayton, ...amdahl!ems, ...uunet!rosevax!mmm} !viper!ns!logajan -keithl@vice.ICO.TEK.COM (Keith Lofstrom) (09/04/88)
"Continuous" frequency change, as in swept frequencies or FM, is a reasonably accurate *approximation*. At radio frequencies of 1 GHz, an energy quanta is 6.6E-25 Joules. Thermal noise at 300 Kelvin is around 4e-21 Joules, about 6000 times larger. We can't see the quanta; they are buried in noise. It's easier just to ignore the quantum effects unless the frequencies are higher or the temperatures are lower. -- Keith Lofstrom ...!tektronix!vice!keithl keithl@vice.TEK.COM MS 59-316, Tektronix, PO 500, Beaverton OR 97077 (503)-627-4052
markz@ssc.UUCP (Mark Zenier) (09/06/88)
In article <805@ns.UUCP>, logajan@ns.UUCP (John Logajan x3118) writes: | We generally associate radio transmission with wave properties. But we | also know that such emissions have photonic-particle like properties. | | The point I have trouble seeing is how to explain continuous frequency | change in terms of discrete photons. Frequency shifting is easy to | visualise from a waveform point of view -- but in a particle point of | view, isn't one forced to make the assumption that frequency shifting | can only occur in quantum steps -- that there is no such thing as a | continuously smooth frequency change. | | Perhaps I should have used the term "discrete steps" rather than quantum | steps, since I didn't mean to imply that each step was constrained to be | any specific "leap" from the previous. Photon energy (in Joules) = 6.6256e-34 (Planck's Constant) * frequency (hz) Pretty small steps. Mark Zenier uunet!pilchuck!ssc!markz "He did decide, though, that with more time and a great deal of mental effort, he could probably turn the activity into an acceptable perversion"-Mick Farren