It's WE-MAN!'s Funny Things To Do With Your Microwave Oven Page It's WE-MAN!'s Funny Things To Do With Your Microwave Oven Page



Hi,

I came across your website and spent a good 20 minutes killing myself laughing! I'm looking forward to getting a new microwave soon so I can do all kinds of crazy stuff to the old one :-)

I thought I might write in and tell you the physics (or chemistry, depending on your preferences) behind fluro tube operation. They contain a highly-excitable gas, such as neon, at a low pressure. You plug your tube into a power supply with a capacitor, which ensures there is enough charge for electrons to "jump the gap" between the two ends of the tube. So the capacitor charges, and releases a steady stream of electrons which whiz across the tube with some speed. However, there's a whole heap of gas molecules in the tube, and they're being "buckshot" by a whole bunch of electrons.

let's say one electron comes towards a single gas atom. As you may recall from your highschool/college physics, the electron has a certain amount of energy. But electrons aren't very greedy, and they don't mind giving some of it away. As the electron smacks into the gas atom, it gives it some energy. BUT, the atom can only use this energy if the electron has more than a certain amount (typically measured in electron volts, eV). So if the electron doesn't have enough energy (because it had already passed some on to other atoms, or perhaps it never had enough to begin with), it will simply elastically collide, and the atom will give it's energy back.

Ok, so we now have a slightly less energetic electron, which goes on to do it's business elsewhere, and an atom with it's stolen energy. What does it do with this, I hear you ask. Well, through some strange Quantum Mechanics (which takes about 3 hours to explain), the atom lets one of it's internal electrons become "excited", allowing it to move slightly further away from the nucleus. But, the electron isn't really stable here, and the atom itself WANTS the electron back close to it's center. But it has too much energy to fall back down to it's normal state. So what does it do? It releases enough energy to fall back down. And they release this energy as light! Now, there's a whole stack of maths which can tell you what wavelength (color) light you get, but they're pretty boring. And there's also a whole series of line spectra which mark particular characteristics of elements and materials.

How does this explain how it works in microwaves? Well, let's look at an intermediate example. Go find yourself a real Tesla Coil (not that crap in Red Alert), which can give you some nice voltages, and nice big sparks. Next, grab your ever-handy fluro tube, and hold it close, but not touching (cause you'll fry yourself if you do!) the coil. And as long as you haven't gone too high in the voltage (I think about 50,000V sounds about right, but you'd want to check first!! It's been three years since I last saw this done), you'll light up the whole room. This works no by current passing through the two electrodes on the tube, but by the electric field. This is yet more complicated physics, but basically every wire creates an electro-magnetic field around it. So when you've got lots of wires with LOTS of current flowing through it, you get a really big electric field! This goes straight through the glass, excites the atoms in exactly the same way as above, and gives that familiar glow.

Can you guess how it works in a microwave now? By using very energetic photons/electrons/waves/whatever (damn duality theory!), you've got more than enough energy to light up your microwave. And that massive energy level is what messes with your body's cells, giving you cancer and stuff.

And quickly, I'll explain why stuff gets so damn hot in there. What happens when you shoot a can sitting on a fence? You tear a great big hole in it, but you also probably knock it off the fence. But we can't rip holes in atoms, can we. No, I think we need something bigger to explain this. Ok, let's find a nice big rock (I'm thinking the size of a small town), and a really big bulldozer. Put this rock on the edge of the grand canyon. Get a run up, and smack into the rock. Congratulations, you've just simulated what happens to a (metal) atom when it's hit by a high-energy particle. How does this make it hot though? Temperature is defined as the average kinetic (moving) energy of a substance. So, if things are moving faster than they were yesterday, it's hotter. So, if you get hundreds of thousands of particles smacking into each atom, things are really going to start moving! It's this constant bombardment which makes things get hot in your microwave -- not just foil and light bulbs, but microwave dinners and leftovers too.

Please feel free to put this on your website! I was up all night writing this, so I hope you or your visitors can find it of some use.

Thanks for some great ideas, and I'll report what else I can find out!

Simon Wilson
xeos_dd@hotmail.com