0
$\begingroup$

Let's imagine a seller scammed you and sold you a Gamma rays / X-rays "oven" instead of a common microwave oven. The power consumption would be the same as a common microwave oven, i.e. about 1 kW, but the oven would use x-rays and/or gamma rays instead of micrometric waves. How would one notice that the oven behaves differently than a common microwave oven?

I do realize that the door of the microwave ovens have holes that let pass visible light but not microwaves, so, for the sake to make the question more interesting, let's assume that the door consists of a thick metallic wall. So essentially the oven looks like a metallic box from the outside.

Would the energy be used to heat the food as much as if microwaves were used? If not, is the energy then wasted to heat the walls of the x-rays oven?

$\endgroup$
2
$\begingroup$

In a past exam question, an experiment "performed by a student" described removing the rotating plate from the microwave and adding a "chocolate bar".

Due to standing waves being formed due to the EM waves reflecting off the opposite side to the transmitter, the "chocolate bar" would only "melt" in certain, periodic dots - at the antinodes.

The wavelength of the light can then be calculated by measuring the distance over $2n+1$ antinodes and then dividing this by $2n$.

We could then calculate the frequency of the EM waves being emitted, since we know $c$ and $f=\frac{c}{\lambda}$ and thus determine whether they are microwaves or x-rays.


Also, x-rays and microwaves have different properties - such as how they interact with organic matter so there is likely some simple test you could do in that sense.

$\endgroup$
  • $\begingroup$ Following this line of thoughts, visible light have antinodes at much shorter length than microwaves, so the chocolate bar should melt almost continuously through it. But that's not what happens of course. It doesn't penetrate well into the chocolate bar at all. However X-rays certainly would! So what would happen should be investigated as you say, from the differences in how X-rays and Gamma rays interact with organic matter. $\endgroup$ – thermomagnetic condensed boson Jun 15 at 21:21
  • 1
    $\begingroup$ Well, plus x-rays can go completely through you with reasonable probability, making them pretty useless for heating. $\endgroup$ – Jon Custer Jun 15 at 21:23
  • $\begingroup$ @JonCuster that's what I suspected. So essentially the X-rays and Gamma rays would be mostly absorbed by the metallic walls, right? Please post this as answer if true... I would accept it. $\endgroup$ – thermomagnetic condensed boson Jun 15 at 21:30
  • 1
    $\begingroup$ microwave ovens have feedhorn assemblies intended to reduce the prevalence of antinodes and hot spots inside the cavity. Would the chocolate bar experiment have really worked like this in practice? $\endgroup$ – niels nielsen Jun 15 at 21:35
  • 1
    $\begingroup$ @JonCuster. wouldn't soft xrays be mostly absorbed by a human body? $\endgroup$ – jmh Jun 15 at 21:55
1
$\begingroup$

Gamma ray doses are measured in sieverts and grays: one joule per kilogram. A dose of 5 sievert is deadly, but the heat developed is negligible: a temperature rise in water of about 0.001 C.

So your kilowatt oven would be visibly ionizing the air, I think.

$\endgroup$
  • $\begingroup$ So essentially most of the energy of the gamma rays is used to break atomic/molecular bounds instead of making them vibrate? $\endgroup$ – thermomagnetic condensed boson Jun 16 at 20:07
  • 1
    $\begingroup$ A gamma photon gives rise to high-energy electrons which in turn produce other ionizations. Finally, all the energy becomes heat. $\endgroup$ – Pieter Jun 16 at 20:14
  • $\begingroup$ Hmm, so in the end a part of the energy is lost to ionize (and heat up?) the air. And what is absorbed by the food translates as heat too. So, I am a bit lost with the difference(s) with the common microwave oven, with regards to the heating of the food. $\endgroup$ – thermomagnetic condensed boson Jun 16 at 20:27
  • 1
    $\begingroup$ You asked what you would see (extremely hypothetical question). I answered that you would likely observe an airglow in the oven. $\endgroup$ – Pieter Jun 16 at 20:30
  • 1
    $\begingroup$ Gamma rays do not care about walls, whether it is concrete or aluminum. Gamma rays will mostly pass through food too. $\endgroup$ – Pieter Jun 16 at 20:49

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.