measuring degrees with fist

It's said that a fist at arms length is about 10 degrees of sky. BUT, when I
use a sun filter held up to the sun and measure with a ruler, the suns width
(1/2 degree) is about 3 mm. So a degree is about 5mm. This is counter to the
general rule. My fist is about 10 cm wide so 10mm = 1 degree, not 5. What
is wrong with that picture?

On Apr 30, 4:37 pm, "Pippi" wrote:
It's said that a fist at arms length is about 10 degrees of sky. BUT, when I
use a sun filter held up to the sun and measure with a ruler, the suns width
(1/2 degree) is about 3 mm. So a degree is about 5mm. This is counter to the
general rule. My fist is about 10 cm wide so 10mm = 1 degree, not 5. What
is wrong with that picture?

Hi
My fist is about 8.5 degrees.
Dwight

"Pippi" wrote in news:qRJCn.2919$z%6.380@edtnps83:

It's said that a fist at arms length is about 10 degrees of sky. BUT,
when I use a sun filter held up to the sun and measure with a ruler,
the suns width (1/2 degree) is about 3 mm. So a degree is about 5mm.
This is counter to the general rule. My fist is about 10 cm wide so
10mm = 1 degree, not 5. What is wrong with that picture?

Linear and angular measurements are not the same. 1x linear = y degrees
does _not_ mean that 10x linear = 10y degrees. On the celestial sphere,
the distance across your closed fist is the length of a chord on a circle.
The angular measurement concerns a circle on the celestial sphere, the
endpoints of which are extended to the celestial sphere from the points on
the either side of your fist. Clear Skies - Canopus56

On 2010-04-30, Pippi wrote:
It's said that a fist at arms length is about 10 degrees of sky. BUT, when I
use a sun filter held up to the sun and measure with a ruler, the suns width
(1/2 degree) is about 3 mm. So a degree is about 5mm. This is counter to the
general rule. My fist is about 10 cm wide so 10mm = 1 degree, not 5. What
is wrong with that picture?

Ham fisted? Anyhow, if 3 mm is 1/2 degree, 6 mm is one degree.

Bud

It was an estimate....


"William Hamblen" wrote in message
et...
On 2010-04-30, Pippi wrote:
It's said that a fist at arms length is about 10 degrees of sky. BUT,
when I
use a sun filter held up to the sun and measure with a ruler, the suns
width
(1/2 degree) is about 3 mm. So a degree is about 5mm. This is counter to
the
general rule. My fist is about 10 cm wide so 10mm = 1 degree, not 5.
What
is wrong with that picture?

Ham fisted? Anyhow, if 3 mm is 1/2 degree, 6 mm is one degree.

Bud

In article ,
William Hamblen wrote:
On 2010-04-30, Pippi wrote:
It's said that a fist at arms length is about 10 degrees of sky. BUT, when I
use a sun filter held up to the sun and measure with a ruler, the suns width
(1/2 degree) is about 3 mm. So a degree is about 5mm. This is counter to the
general rule. My fist is about 10 cm wide so 10mm = 1 degree, not 5. What
is wrong with that picture?

Ham fisted? Anyhow, if 3 mm is 1/2 degree, 6 mm is one degree.

The big dipper can be used as a reference :

http://celestialwonders.com/articles...ositioning.pdf

The shortest spans in the big dipper are very close to 4.5 degrees,
the second shortest, like the two dipper ones furthest from the
handle that point to polaris, and 5.4 degrees.

The reference gives a lot of star pairs where you can measure the
angle of your fist.

-- mrr

Pippi wrote:
It's said that a fist at arms length is about 10 degrees of sky. BUT, when I
use a sun filter held up to the sun and measure with a ruler, the suns width
(1/2 degree) is about 3 mm. So a degree is about 5mm. This is counter to the
general rule. My fist is about 10 cm wide so 10mm = 1 degree, not 5. *What
is wrong with that picture?

To cover only 3 mm, the Sun has to be measured by a ruler held
at about 35 cm, or about 14 inches. If your arm really is that
short, you'll have to develop your own rule of thumb (as it
were) to figure out angular measurements. For instance, ten
degrees would cover about 6 cm, or perhaps three of your
fingers.

But otherwise, you may just have to stretch out your fist all
the way before the measurements make sense.

--
Brian Tung (posting from Google Groups)
The Astronomy Corner at http://www.astronomycorner.net/
Unofficial C5+ Page at http://www.astronomycorner.net/c5plus/
My PleiadAtlas Page at http://www.astronomycorner.net/pleiadatlas/
My Own Personal FAQ at http://www.astronomycorner.net/reference/faq.html