ASK DR. BOLI.

Dear Dr. Boli: I know how electric light bulbs work, but how do LEDs work? No one seems to be able to explain it to me. I could look it up in Wikipedia, of course, but I don’t trust collective wisdom, which sounds suspiciously communist to me. —Sincerely, Pembroke Birch, Jr., Vice-President, North American Association of Suspicious People.

Dear Sir: Diodes per se are not naturally luminescent, and do not become so until exposed to a bright idea. It is the brightness of the idea that causes the chemicals in the diode to luminesce. Huge factories in Malaysia, China, Indonesia, and other Asian countries are filled with the region’s best minds, employed at ruinously low hourly wages to think up bright ideas, each one of which illuminates a single diode. Almost all these ideas are lost forever as soon as they are thought up, since once a diode is rendered luminescent, the worker must immediately begin thinking up another bright idea to illuminate the next diode. Thus the little glowing red light on your battery-charger may be the only memorial of a lost cure for cancer or a sane appoach to economic justice.

You are right to distrust Wikipedia. Dr. Boli looked up the article on light-emitting diodes, and the explanation given there was ridiculously  implausible.