Can a Tower Emit Light by Changing its Frequency to Match Visible Light?

[x+iy]

In electromagnetic spectrum, frequency & wavelength differentiate between radio waves and light waves.

So, if the frequency of the radio wave being transmitted by a tower is changed to match the frequency of the visible light, will tower start emanating light?

 

[granpa]

frequency of visible light:

http://www.wolframalpha.com/input/?i=frequency+of+visible+light​

wavelength of visible light:

http://www.wolframalpha.com/input/?i=c/450+Thz​

 

[Vanadium 50]

Sure, but radio transmitters have a maximum frequency that is many orders of magnitude below optical.

 

[cragar]

if you were traveling at the tower with a high enough velocity you would see it Doppler shifted to visible light.

 

[cjameshuff]

http://apod.nasa.gov/apod/image/0711/lighthouse_westcott_big.jpg

More seriously, the radiation emitted by a tower and visible light differ only in wavelength, yes. However, the transmitter antenna's ability to emit also depends on the wavelength. Radio waves have wavelengths of tens of meters down to centimeters depending on the type of radio, visible light has wavelengths of hundreds of nanometers, the eye is most sensitive to light with a wavelength of about half a micron.

So in principle, yes, but in reality there are practical limitations. Some experimental work has been done with microscopic antennas made using integrated circuit techniques that do operate at near optical wavelengths. (look up "nantennas")

 

[Dr Lots-o'watts]

If you want to make a tower emit visible light, you need to makes its electrons vibrate at visible frequencies. In practice, this could be done by heating the tower until it becomes red-glowing hot. (of course, the difference between heating and AC current is that heating involves many frequencies in random directions, while an AC current is a single frequency polarized along the length of the tower).

But such high frequencies are associated with very high energies, so depending on the specific metal or alloy the tower is made of, the inter-atomic bonds may break, and the tower, melt down.