Robert0288 said:Might be a stupid question. But since the speed of light is so fast, and there is a limited range that you can send things without bouncing off the ionosphere, wouldn't any freq change be negligible?
GnyHwy said:If a radio transmission is sent in an easterly or westerly direction, does the frequency change?
What about north/south?
Robert0288 said:Might be a stupid question. But since the speed of light is so fast, and there is a limited range that you can send things without bouncing off the ionosphere, wouldn't any freq change be negligible?
GnyHwy said:In an attempt to keep this thread alive, I will answer my own question. Sigs or physics geeks, please feel free to critique.
The radio freq must change because the speed of light will not. Freq=speed of light/wavelength. Because the speed of light stays constant, the freq and and wavelength must change and are dependant on each other. In the context of the question, the Earth is already travelling in an easterly direction (rotation). This rotation attempts to speed up the speed of light. This cannot happen, therefore the freq and wavelength must change.
Answer: When a radio transmission is sent in an easterly direction, the freq increases and the wavelength shortens (decreases). If transmitting in the westerly direction, it is the opposite. The frequency decreases, and the wavelength gets longer (increases).
collinscj043 said:There are no stupid questions! The Frequency change would be extremely negligible i.e. Earth's equatorial speed divide by the speed of light ~ (465/300000000) m/s= 1.88 × 10^-6 change in hertz or 1.88 x 10^-12 MHz. You would be fairly hard pressed to detect this difference in frequency and wavelength.
I wouldn't say the rotation attempts to speed up the light. As an observer on the ground the light should appear to be moving 465 m/s faster, which be pretty hard to observe, but because this would violate special relativity the frequency shifts by ~ 465/c.
Ref
http://en.wikipedia.org/wiki/Relativistic_Doppler_effect#Motion_in_an_arbitrary_direction
jparkin said:That's along the lines of what I was thinking, since the speed Earth rotates is negligible compared to c.
Next physics question;
If no external torque is being applied to a closed system, what can we deduce about the cross product of the momentum and the velocity of the said system? What useful information does this realization give us in terms of the mechanics of the system?
Hint below..
.
What specific quality of the system is conserved?
collinscj043 said:In a closed system as described above both the momentum and velocity vectors would be parallel thus their cross product would be zero. Conservation of angular momentum tells us that a system in rotational motion will remain in motion until acted on by some external force/torque. The really cool thing that conservation of angular momentum is that it also predicts that if the shape/density of a system changes then its velocity must change respectively to conserve angular momentum. i.e. Like when a figure skater pulls their outstretched arms toward their chest. or when galaxies formed after the big bang.
Shipwreck said:Just to screw it up even more, Here's what I came up with to ask:
What connection is there between Canada's submarines and William Shakespeare?
Shipwreck said:Just to screw it up even more, Here's what I came up with to ask:
What connection is there between Canada's submarines and William Shakespeare?