The EM spectrum

[Incendia]

My questions are:

Could the EM spectrum go beyond Radio waves? Waves with an approximate wavelength scale of longer than a building...perhaps as long as several kilometres...

Is it possible for the wavelengths to get to long that they become a flat line?

On the other end of the scale, Could there be waves as shorter than Atomic Nuclei? As short as Leptons/Quarks?

Could they get so short as to stop in a vertical line?

 

It's just that shouldn't the end of the spectrum be where the waves can't get any long and are just a flat line and where the waves are so short the stop at a flat vertical line?

These may not be visible in nature [we would just have to see] but perhaps we could find out in labs...Has anyone ever tried?

[Sisyphus]

Well, per relativity, wavelength is frame dependent. So, in a way, a given photon already is every wavelength, from arbitrarily small to arbitrarily large, depending on which frame of reference you pick. In a reference frame in which the emitting object is moving, the photons emitted "behind" will be redshifted (increased wavelength), and those emitted "forwards" will be blueshifted (decreased wavelength). That will never be infinitely small or infinitely large (flat line), just arbitrarily large. Furthermore, there is gravitational redshift: "climbing out" of a gravity well redshifts light. And the gravitational redshift at the event horizon of a black hole approaches infinity, so I guess you could say that is the "flat line," more or less.

[TonyMcC]

Any conductor carrying alternating current will radiate EM waves at the same frequency. For example you are subject to EM radiation at 60 Hz (USA) or 50 Hz (UK) just by being in your home.

Edited November 19, 2010 by TonyMcC

[Incendia]

...I think Tony's answer was the most useful...

 

So has anyone tried to measure 1Hz EM radiation?

[swansont]

[math]\lambda=\frac{c}{\nu}[/math], so 1 Hz corresponds to 300,000 km. You'd need an antenna of roughly the same size, i.e. significantly bigger than the size of the earth.

[TonyMcC]

Yes swansont, if you are looking for efficient reception using a dipole aerial. However just connect a lead as an aerial to the input of a cathode ray oscilloscope set to the a.c. input , turn up the sensitivity, and you can see the signals. As I understand it a changing magnetic field in space or air will always set up a changing electric field at right angles to it.

Edited November 20, 2010 by TonyMcC