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Re: Sun's distance



And Leigh when is 499s more "useful" than 8 minutes?
If on a given day the sun looks about to go supernova,
you always stay within 499s of your personal wormhole
escape chute, perhaps? ;-)

Seriously, I think students can memorize & conceptualize
the 4th dimension of time better with 8 minutes than
with 499 (or 500) s.

If asked to guess cold, I would not be surprised if students'
guess of the light time to the Sun was off by 4 to 8 orders of
magnitude, so 17 s off is a huge improvement.

Cheers,
Bill Larson
Geneva, Switzerland



----- Original Message -----
From: Leigh Palmer <palmer@SFU.CA>
To: <PHYS-L@lists.nau.edu>
Sent: 2000 February 22 12:42 AM
Subject: Re: Sun's distance


Just a note. Two of the numbers I carry in my head:

c = 299 792 458 m/s 1 au = 499 light seconds

Brian's note evoked this because that 499 is really
499.00. The round figure of 500 light seconds about
0.2 % high. "Eight minutes" is terrible, even from
the Sun's photosphere. It's more like 8 minutes 17
seconds. I consider this a large difference, yet
the "eight minutes" is probably better known than
the much more accurate 150 million kilometers.

Leigh