Well, not really exploded. The door shot open and sprayed water onto the counter and floor. Here’s the details. I was boiling water in a Pyrex measuring cup to make jello. My usual MO is to put it in the microwave, set it for 3 minutes or so, watch it and take it out when it starts to boil. This time the phone rang while the microwave was running, so I wound up letting the 3 minutes run out. When I was done on the phone, I just set it for 1 more minute, figuring the water was already pretty hot. About 30 seconds later - BOOM! The door flew open, and water sprayed all over the place, up to 3 feet away. Only about 1/4 of the orignal water was left in the cup.
I’ve read Cecil’s and the Mailbag articles about boiling water in the microwave, and here’s what I think happened - on the first heating, the water came to a boil as it usually does. After the microwave shut off, it cooled slightly, and more importantly, was now at a uniform temperature throughout the cup, since it had all previously been at the boiling point. Then, when I turned the microwave back on, it superheated until something happened to cause a nucleation site, then boom - lots of steam immediately generated - enough to force the door open.
BTW, my wife freaked out, but my 4 year old daughter thought it was really cool. She’s definitely going to be daddy’s little scientist.
I had a friend tell me that his hot water went berserk when he stirred it after nuking it to boiling. That’s some powerful stuff you got there, buddy.
Years ago (circa 1989) I was in New York for a press conference to announce a new portable computer. One of the national science journalists – it might have been with the NY Times or Ira Flatow, of NPR – told a similar story.
He’d been on LA morning television and was going to show how water could get superheated. The experiment: take a cup of water, heat it for 3 minutes, then put a teabag in. When the teabag goes in, the introduction of the “impurity” causes the water to start boiling.
“I’d been scheduled for 7:05 a.m. but they had a guest run long, so we reset the microwave to reheat the water for another minute,” he said.
Well, they didn’t make 7:05 – or 7:10 – so they reheated the water a third time for a minute at 7:15 when “Boom!” the door comes flying off the microwave.
The science journalist was sufficiently chastened – but not so the TV camera people, who said, “Wow! That was cool! Can you do it again?”
Best regards,
Mooney252
Doesn’t anyone learn anything from the Straight Dope?
I mean first of all almost everyone on the boards knows water + microwave = bad news, you’ve shown you know (now, at least) and secondly and most importantly:
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Why didn’t you take a picture of said BOOM!?
Really you must learn. 
You know, that was exactly my thought on seeing the thread title. 
I always use the teakettle, myself. Years and years ago I did a stove-vs-microwave test and the stove (barely) won, so teakettle it is. Of course, I had (and still have) a fairly wimpy microwave, so a high-powered one may produce different results. And of course, you don’t get that cool blast-the-door-off-its-hinges effect with a teakettle!
You might if you put the teakettle in the microwave…
Just a thought.
–Trout
(who also loves it when things go BOOM)
A photo would have been kind of dull - just an open, wet microwave and wet counter. However, I wouldn’t be surprised if the camcorder is serendipitously on and taping the microwave the next time this occurs. Given that this is a brand new house (we’ve been in for 3 whole weeks) and my wife’s previous reaction, I may have to wait a while before trying again.
OOOH!
Wave Motion Gun!
How very Yamato of you, muldoonthief! 