Facts of Life
Q: Is there a maximum size that raindrops can be?
A. Yes. Any raindrop larger than seven millimetres
in diameter will split ino pieces as it falls. Raindrops are made of minute
water particles that bond together in cluds. The larger raindrops become,
the less effective their surface tension is at holding them together. This
makes them increasingly unstable, and as they pick up speed on their way
to earth, turbulence and other aerodynamic forces will rip them apart. This
will normaly happen to a seven-millimetre-wide droplet when it hits a speed
of around 30 kilometres per hour.
Q. How do quicksand work?
A. Quicksand is a pocket of ordinary sand that
has water continuously flowing up through it from an underground source,
such as a spring. The flow lifts the grains of sand apart, but is not strong
enough to disperse them completely and the resultant thick soup can look
like a solid mass - until you step into it and slowly start sinking.
Q. Why do we drink a "toast" to people?
A. In the 1600s, people flavoured their drinks
with spiced toast. If you toasted to someone, you were saying you held them
in such high esteem that the very sound of their name flavoured a drink
as the spiced toast might.
Q: Is there a maximum size that raindrops can be?
A. Yes. Any raindrop larger than seven millimetres
in diameter will split ino pieces as it falls. Raindrops are made of minute
water particles that bond together in cluds. The larger raindrops become,
the less effective their surface tension is at holding them together. This
makes them increasingly unstable, and as they pick up speed on their way
to earth, turbulence and other aerodynamic forces will rip them apart. This
will normaly happen to a seven-millimetre-wide droplet when it hits a speed
of around 30 kilometres per hour.
Q. How do quicksand work?
A. Quicksand is a pocket of ordinary sand that
has water continuously flowing up through it from an underground source,
such as a spring. The flow lifts the grains of sand apart, but is not strong
enough to disperse them completely and the resultant thick soup can look
like a solid mass - until you step into it and slowly start sinking.
Q. Why do we drink a "toast" to people?
A. In the 1600s, people flavoured their drinks
with spiced toast. If you toasted to someone, you were saying you held them
in such high esteem that the very sound of their name flavoured a drink
as the spiced toast might.