domingo, 28 de noviembre de 2010

Microwave Synthesis And Ramen Noodles

Microwaves are a low frequency light, at least compared to visible light, say, or ionizing radiation like gamma rays. Thus, microwaves are quite harmless. A microwave oven baths the food in an oscillating electro-magnetic field. Molecules with permanent electrical dipole moments wiggle in the field and thus heat up the food.

Ok, lets google "microwave danger". Wow, a barrage of pseudo-science about how microwaves slowly kill you and your family. Microwaves supposedly distort the molecules and natural energy in the food and of course, they were invented by the Nazis during the third Reich – who else would come up with such evil? Anyways, they are not natural like the sun, because "microwaves from the sun are based on principles of pulsed direct current (DC) that don't create frictional heat" ???

A few diamonds in the rough: Serious studies quantifying carcinogens in microwave food. Of course, these you obtain much more when frying or eating from the BBQ grill. Large organic molecules in baby milk may isomerize in the microwave oven. What is the conclusion? No big problem, we are in the know, physics has immunized me against rhetoric about supposedly "natural" stuff and why natural should be good by default. I am not expert in all fields, but there is the scientific method, peer review, and so on. Surely, if there was a problem, we would know by now. Or would we?

In our lab, we synthesize nanometer sized particles. Certain particles, like the one pictured below, we cannot make without microwaves. High power? Nope - usual kitchen appliance on the low or warm setting, a few minutes max. Do we know why the microwaves have this effect? I have not the slightest idea! My paper needs references, so I waffle on about the "microwave effect": is it thermal or non-thermal?

Nano-porous micro-carbon spheres with only about several hundred nanometers diameter having metal nanoparticles in its interior, highly catalytic (read: bio active). We make these with help of a conventional microwave oven, 1014 at a time, easily scalable. The metals involved here are from ionic solutions with low concentrations (like in foods) and not much reducer is used either. Vitamin C is such a reducer and at high concentrations in many foods. We do not know why microwaves are necessary or what such compounds would do if digested, nor are there test for unknown nano-compounds in microwaved food.

Our novel results should "inspire much future research" – so I write, and it is accepted by peer review. What is it: Do we know microwaves sufficiently or do we need much future research? Would a chemical test for carcinogens or isomers find that the molecules are actually present in form of nanoparticles? No! Do we know what novel nanoparticles do inside of us, given that biology is basically naturally evolved nanotech? Not a clue! Our papers claim potentially "strong catalytic activity due to non-trivial morphologies, crystallographic structures, and size effects".

Do we know what kind of nanoparticles or refolded proteins (involved in prion diseases and apparently also Alzheimer's) develop inside a burrito or pizza that was poorly defrosted and cooked on the high power setting in a microwave oven? I do not. I probably ate more than two thousand of those as a busy graduate student.

What do I know? On one hand, my Pleistocene mind and my kind of body evolved by natural selection and cooking over fire has been around for a relatively long while, but microwaves not. I also know that I too often think I know although I do not. I could write a series of posts listing all the facts I deemed obvious in the light of basic scientific understanding and that I had to personally give up because some stupid, ugly tidbit of data hit me over the head. On the other hand, I do not want to present a toehold to esoteric pseudoscience. I do not fear "big pharma" conspiring with some evil microwave oven military complex conglomerates trying to shut me up, but I do fear being quoted in support of the "teach the controversy" strategy of creationists, global warming denialists, and suchlike.

Yesterday, my dearest visits me in my office. She puts dry Ramen noodles into a bowl, adds cold water, and off it goes into the microwave oven. She does neither consider that the water has had no time to enter the hard noodles, nor that the microwave frequency is not actually tuned to only excite the water. She is a lay person, she respects science, and scientists say that microwave cooking is fine. Piping hot noodles in front of the computer screen on my desk, the steam swirls the transmission electron microscope images of our lab's newest samples. Bon Appetit!



C.I: 17.557.095


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