Gene Nygaard wrote:

On Thu, 28 Aug 2003 12:49:30 +0000, root
wrote:

Pat Russell wrote:

My vario is calibrated in megaparsecs per millenium. Very
handy.

According to my calculations, this should be near 0.5 mm/s.
You need a very big scale.

Try again. What do you think a millennium is? A parsec? The prefix
mega-?

1 Mpc/ka = 978 Gm/s, or about 3262 times the speed of light. He's got
bigger problems than you thought.

In other words, even one parsec (without the prefix) per millenium is
nearly 1 Mm/s (978 km/s). Thus 1 microparsec per millennium is equal
to a meter per second, within the precision many of you accept with
knots and the like.

Gene Nygaard
http://ourworld.compuserve.com/homepages/Gene_Nygaard/

I just forgot the mega, I computed a parsec/millenium. Here is what I
did:

1 parsec is the distance of something having a parallax of 1 second, i.e.
the distance (from the sun) where the diameter of the orbit of the earth
is seen with an angle of 1 second. I don't remember this diameter but I
remember that the light coming from the sun needs 8 minutes to do that,
so the diameter should be 8*2*60*3*10^8 (diameter = 2*radius, 60 seconds
in a minute, speed of light 3*10^8 m/s) = 4800000000 m. 1 second is PI/(180*60*60)
radians, so 1 parsec is 4800000000/(PI/(180*60*60)), this is roughly 10^15 m.
A year is nearly 365.25 days, i.e. 365.25*24*60*60 seconds = 1980281535681600 s.
A millenium is 1980281535681600*1000 = 1980281535681600000 seconds or roughly
2*10^18 s. So a parsec/millenium is 10^15/(2*10^18) = 0.5*10^-3 m/s. A megaparsec
per millenium should be ~ 500 m/s. A huge unit for a vario in a glider, although
well under the speed of the light.

Well I was never good in calculations, so if there is a error, please point where.