Pat Naughtin wrote:
....
> Lightning: � If the hair on your arm and head start to stand on end, the
> lightning is going to strike near you. Drop to your knees and lean forward.
> Put your hands on your knees to avoid ground current that can occur if the
> lightning strikes within 50 metres.
A better recommendation is to squat on your two feet with your feet as
close together as possible. Odds are that you will have shoes on and
that may help a tiny bit; wet knees are going to be good conductors, as
well as adding opportunities for you to experience a voltage drop across
two parts of your body as the strike's current dissipates through the
ground. Coordination and sense of balance must be provided by the user.
...
> Measuring the moon: � The moon covers almost one degree of sky. You can
> measure this with your little finger nail (about 10 mm) at arm's length
> (about 700 mm); your little fingernail will just cover the face of the Moon.
Not quite! The Moon's apparent size is closer to 0.5�, on the average
(close to that of the Sun). Flipping through my 2001 Nautical almanac I
see semidiameter (SD) values ranging from 14.7 to 16.7 minutes of arc.
The Sun's SD ranges from 15.8 to 16.3 minutes of arc.
Jim
