diameter of moon

[leemaj]

hi, i need to know how to find the diameter of the moon using my finger and the moon, and knowing that the distance from the earth to the moon 368500 km.

[revil]

hmm... hold your finger up to the moon so the finger hits both ends of the moon. measure the distance between your eye and your finger (i'll call this X and F the length of your finger. both X and F must be in the same units for this to work.). since this is a simular triangle problem, it should be a simple ratio problem. i could be wrong, i just got up from a nap.

so what we'll get is:
[ F * 368500 km ] / X = diameter of moon
since [ F / X ], they need to be in the same units so they will cancel out.

there will be lots of error in this because your not a master fingerer like myself and because this is a rough estimate.

hope that helps.

[BrewMaster]

sounds right to me...but I'm too lazy to go and figure it all out, so i'll take revil's word. the only thing is that if it's not a full moon, you're not seeing the whole moon and therefore not measuring the whole diameter. just my thought on where error might come in.

[Cheesypuff]

Nice revil...I'm a math major...and I have no idea what the heezie I"m doing...just joking...nice formula...I get it.

[leemaj]

i think you are right..my friend tried it and got 7000km for the diameter, but it is actually more like 3500, so i shall try it once i can see the moon..clouds are out right now

[hapoo]

Originally posted by leemaj
i think you are right..my friend tried it and got 7000km for the diameter, but it is actually more like 3500, so i shall try it once i can see the moon..clouds are out right now


you sure thats not the radius?

[Cheesypuff]

I think thats the diameter that he got homie...I tried it out and the formula is really correct...give or take 3% error.

[leemaj]

hmm...what did you get for X and F?

[Cheesypuff]

X = the distance from you to your finger
F = the diameter of your finger

[Markel]

If you google, you find out that the moon's diameter is 2,140 miles (3,476 km). Which proves that I can figure the moon's diameter using my fingertips. :D

[leemaj]

Originally posted by Cheesypuff
X = the distance from you to your finger
F = the diameter of your finger

yea i know that, but what actual numbers did you get when you tried it. i wanna compare them to mine.

[sho.gun]

Just measure the diameter of a quarter, they're about the same size...

[leemaj]

uh huh....

[BrewMaster]

Originally posted by Markel
If you google, you find out that the moon's diameter is 2,140 miles (3,476 km). Which proves that I can figure the moon's diameter using my fingertips. :D

hehe. brilliant.

[revil]

Originally posted by Cheesypuff
X = the distance from you to your finger
heh, let's hope X is not larger than 1 meter....

[revil]

Originally posted by sho.gun
Just measure the diameter of a quarter, they're about the same size...
well, actually, that's a good way to do it when only part of the moon is showing. this way the quarter will fill in what isn't lighted on the moon.

[BrewMaster]

something about that seems like it won't work. it still depends on the distance of the quarter fro myour eye and how big you think the moon should be, etc. good luck tho.

[revil]

Originally posted by BrewMaster
something about that seems like it won't work. it still depends on the distance of the quarter fro myour eye and how big you think the moon should be, etc. good luck tho.

of course it still depends on the distance from your eye. just replace the finger with a quarter. the moon is round (for our estimation purposes) and so is the quarter, so it's still a simular triangle problem.

[topane]

M-O-O-N spells Tom Cullen

[revil]

Originally posted by topane
M-O-O-N spells Tom Cullen
you've just confused the hell out of me. But I did just wake up from another nap, so...