• Question: Do you think there is a possibility that there could be more to the spectrum (and electromagnetic spectrum) as we know it, if more research was carried out? And if more research was carried out would there be specific reasons for why it is or belongs there?

    Asked by crazybritto to Rob, James, Marcus, Martin, Suzanne on 19 Mar 2012. This question was also asked by katiecauldwell.
    • Photo: Martin Zaltz Austwick

      Martin Zaltz Austwick answered on 19 Mar 2012:


      There is! We just can’t see it. The electromagnetic spectrum goes from radio waves, microwaves, infra red, red, orange, yellow, green, blue, violet, ultra violet, X-rays, gamma rays and high energy cosmic rays! Light is electromagnetic waves, and so are all of the other things I just mentioned: all that changes is the wavelength decreases and frequency increases. For example, microwaves have a wavelength (distance between wave peaks) of a few mm. Visible light wavelength is around one thousandth of a mm.

    • Photo: James Boone

      James Boone answered on 19 Mar 2012:


      That’s a good question. In short, I have no idea. The current range of frequencies that we know of range enormously from gamma radiation (very high frequency but tiny wavelength the width of an atom) to long radio waves (can be hundreds of metres long!). I don’t think there’s an upper limit to how long an electromagnetic wave can be. The lower limit would be how much energy we could put into making a photon (smaller wavelength means higher frequency and therefore higher energy).

    • Photo: Marcus Gallagher-Jones

      Marcus Gallagher-Jones answered on 20 Mar 2012:


      Hmm the problem with a spectrum is that it isn’t discrete. It defines a continuous series of values. What i mean is that it refers to essentially all wavelengths of light from just above 0 to infinity. For me my focus is on light with wavelengths below 1angstrom (about 0.1nm) as this is close to the size of atoms. I think the main problem would be in their detection rather than their existence.

    • Photo: Suzanne McEndoo

      Suzanne McEndoo answered on 21 Mar 2012:


      One thing I always wonder about is the upper limit. We might be able to put a lower bound on the electromagnetic spectrum, based on quantum physics, but is there a reason why we might have a highest frequency? I don’t know about that.

      I’m not sure the spectrum will grow much beyond what we have now, other than doing things with higher or lower frequencies. We’d have to change a lot of what we know about light to change how we catagorise it, like if there was a way to have imaginary numbers in the frequency (which I don’t think makes any sense, but as an example of how the spectrum could have more to it).

    • Photo: Robert Thompson

      Robert Thompson answered on 21 Mar 2012:


      Great questions. The EM spectrum is continuous so we are always finding different uses for different parts of it. One of the things they research in my lab is Terra HZ radiation, this is a part of the EM spectrum between infra-red and microwaves. It has a lot of uses, one of the things they are looking at using it for in my lab is trying to detect cancer cells .

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