mciburton

This was forwarded to me by a friend. I checked the truth of it on urban
legends so it's a good warning.

Cia

to a mere selection of all my generally curious, science-y, nukro-using

friends... be safe and lotsa love afbb


PLEASE READ ~ IT'S FROM A FRIEND!


I was very glad to get this email from a friend, because I have been

guilty of heating water in a microwave many times. You'll be glad you

read it.

About five days ago, my 26-year-old son decided to have a
cup of instant
coffee. He took a cup of water and put it in the microwave to
heat it up
(something that he had done numerous times before). I am not sure
how
long
he set the timer for but he told me he wanted to bring the
water to a
boil.
When the timer shut the oven off, he removed the cup
from the oven. As he
looked into the cup he noted that the water was not
boiling. Then
instantly the water in the cup "blew up" into his face. The
cup remained
intact until he threw it out of his hand but all the water had
flown out
into his face due to the buildup of energy.
His whole face is
blistered and he has 1st and 2nd degree burns to his
face, which may leave
scarring. He may also have lost partial sight in
his left eye. While at the
hospital, the doctor who was attending to him
stated that this is a fairly
common occurrence and water (alone) should
never be heated in a microwave
oven.
If water is heated in this manner, something such as a wooden stir
stick
or a tea bag should be placed in the cup to diffuse the energy.

Here is what our science teacher has to say on the matter: "Thanks for

the microwave warning. I have seen this happen before. It is caused by a

phenomenon known as super heating. It can occur any time water is heated

and will particularly occur if the vessel that the water is heated in is

new.
What happens is that the water heats faster than the vapor bubbles
can
form. If the cup is very new then it is unlikely to have small surface

scratches inside it that provide a place for the bubbles to form. As the

bubbles
cannot form and release some of the heat that has built up, the
liquid
does not boil, and the liquid continues to heat up well past its
boiling
point.
What then usually happens is that the liquid is bumped or
jarred, which
is just enough of a shock to cause the bubbles to rapidly form
and expel
the hot liquid. The rapid formation of bubbles is also why a
carbonated
beverage spews when opened after having been shaken.


Please pass this on to everyone you know, it could save a lot of pain
and
suffering.



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