welcome

Feb 28, '08 10:49 PM
for everyone

We are part of the earth and the earth is part of us.

Nobody is sure who first deduced that the world is round. It is most likely that it was done by observing the Earth's shadow on the Moon during a lunar eclipse. Aristotle (384-322 BC) said that it was common knowledge, at least among the learned, so it's been known for at least 2,500 years. We do know that Eratosthenes of Cyrene (Eratosthenes was a Greek mathematician- 276BCto 194BC- who is famous for his work on prime numbers and for measuring the diameter of the earth) was the first to accurately estimate the Earth's diameter, around 220 BC. How he did it is detailed at Astronomy Online.

What he did was use the information that, at noon on the Summer Solstice, the sun shone to the bottom of a well in Syene (now called Aswan), Egypt. This meant that the sun was making a 90° angle to the ground on that day, in Syene.

Eratosthenes then measured the angle of sunlight to the ground in Alexandria, Egypt, at noon on the same day. He used that angle to calculate what fraction of the Earth's circumference (which is 360°) was between Alexandria and Syene. Since he knew the distance to Syene, and that it was exactly south of Alexandria, he was able to calculate the Earth's circumference.

Actually, he didn't have the distance quite right--and Syene isn't exactly south of Alexandria, either.

This was the first reasonable accurate measurement of the Earth's circumference, and it came to about 40,000 km (25,000 miles). We now know that this is an overestimate, but not by too much.

Dan Berger

MadSci Administrator

This is a shot I took many years ago on my Senior Class Trip. It was a Bahama Cruise. This was taken at sunset with just a regular 35mm camera, and then scanned onto the computer and just edited larger for you to see. To return to Picture Perfect, just click the camera at the top for the rules, host, and others' entries. Have a great weekend and Happy viewing, lilangelwolf

PS: If you have posted one, please leave your link with your comments, it makes it much easier and quicker to get back to see yours... Thanks....

Tags: hsdays, pictureperfect, sr class trip, mathematical, infinite

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48 CommentsChronological Reverse Threaded

jayaramanms wrote on Feb 29

Yours is a really beautiful shot and well taken. I liked it very much. Thanks for sharing. Please visit my site -http://jayaramanms.multiply.com/journal/item/77 and mark your comment. Best wishes.

myleftoverturkey wrote on Feb 29

nice picture and love the music!
http://myleftoverturkey.multiply.com/journal/item/16/Picture_Perfect_Theme_-_Infinite_-

eptheresia wrote on Feb 29

an impressive shot at sunset. somehow sunsets always make me feel something special...hmmm

http://eptheresia.multiply.com/journal/item/1/Picture_Perfect_INFINITY

rruzie wrote on Feb 29

I have to triple check, is this the page I always visited every week? Sound serious... not like the usual Lil... am I at the wrong page...?
Anyway, love the picture especially the effect of the sunlight! The info is very refreshing! Thank you for sharing!

Mine is up too, if you have a minute!
http://rruzie.multiply.com/journal/item/91/Picture_Perfect_INFINITE

lindylooh wrote on Feb 29

Great pic and post.

lintang71 wrote on Feb 29

love it.. great picture..
http://lintang71.multiply.com/journal/item/132/Picture_Perfect_INFINITE

mitchylr wrote on Feb 29

Lovely pic Lil. I love sunrise and sunset shots. :-))

Having had a lifelong interest in Astronomy, I already knew most of the info in the article. The only bit I didn't know until I read it is what a smug individual Dan Berger is. Brought up in a world of laptop computers and pocket calculators, he obviously has no conception of just how amazing that calculation was given lack of scientific instruments. His snipes about lack of accuracy in distance and position really do grate on the nerves. Sorry, Lil, that just hit a nerve!!! LOL.

vrilia wrote on Feb 29

lobe sunset...great shot Lil...

http://vrilia.multiply.com/journal/item/41/picture_perfect_InFiNiTe

sweetgely wrote on Feb 29

wow! nice shot... and enjoyed reading... i enjoyed visiting... and yes, thank you for dropping by my page....

riihele wrote on Feb 29

Hei Lil

Gorgeous!
Have a very grand day. Rii :))

My entry is @ this addy:
http://riihele.multiply.com/journal/item/634/PICTURE_PERFECT_INFINITE

danceinsilence wrote on Feb 29

Great shot ... love that stream of gold across the water, just adds to the clarity ... what is somewhat interesting about the earth being round ... when on water and you look outward, you see no signs of curviture anywhere ... flatlined out as far as the eye can see ... anyway, thanks for stopping by my page ... take care 8=)

http://danceinsilence.multiply.com/journal/item/150/Picture_Perfect_Friday_..._Infinite

natty013 wrote on Feb 29

Beautifully captured sunset over the water.
Mine's at: http://natty013.multiply.com/journal/item/26/Picture_Perfect

estimiguelariel wrote on Feb 29

What a wonderful post, thank you for sharing ;o)

http://estimiguelariel.multiply.com/journal/item/188/PICTURE_PERFECT_Infinite

soliloquydownunder wrote on Feb 29

clever blog to go with a pretty shot. :-)

http://soliloquydownunder.multiply.com/journal/item/80/Picture_Perfect_Infinite

vaziry wrote on Feb 29

Fantastic shot , wish you a great weekend my dear .

gilesy01 wrote on Feb 29

Nice and relaxing.

sue980 wrote on Feb 29

Great shot! Thanks for the info,
http://sue980.multiply.com/journal/item/24/PICTURE_PERFECT_INFINITY.

kia909 wrote on Feb 29

I could feel it there would be some mathematics, physics or astronomy this time!
Thanks for the info... and interesting entry!

harleymick wrote on Feb 29

Awesome! The curvature of the earth exemplifies infinite!

Thanks for stopping by mine.

naarta wrote on Feb 29

Wonderful post fits the theme well. Again I do not have one up for this week, hopefully I will be back in the game next week.

jolaranita wrote on Feb 29

nice picture, we went to Bahamas last november we loved it!
http://jolaranita.multiply.com/journal/item/245/picture_perfect_infinite

tallyknight wrote on Feb 29

I love this...sunset shots always please me. Really beautiful.

http://tallyknight.multiply.com/journal/item/41/Picture_Perfect_-_Infinite

dannidoodles wrote on Feb 29

Now that's a senior class trip! Beautiful picture..thanks for stopping by mine :)

bikergirl279 wrote on Feb 29

GORGEOUS!!! Here's mine. Feel free to stop by and take a look. http://bikergirl279.multiply.com/journal/item/316/Picture_Perfect_Friday_Infinate

needledreams2 wrote on Feb 29

Very interesting facts and the shot is gorgeous! Thanks for sharing. Mine is up also at: http://needledreams2.multiply.com/journal/item/657/Picture_Perfect_-_Infinite

compromised wrote on Feb 29, edited on Feb 29

Yahoo came and ate mine out of spite when i sent it to spell check..booohooooo...gotta repost..the cake won't be the same the second time around. I lost the recipe ( take off "McArthur Park"), Gonna try to rewrite tho.

Lol, wish I could have been there with you , cam in hand, snapping away. Nice bit of history to go with the photo.

pestep55 wrote on Feb 29

Interesting info and very calming picture

dragonlette wrote on Feb 29

Great blog and image.
http://dragonlette.multiply.com/journal/item/30/Picture_Perfect_-_Infinite

busterp wrote on Feb 29

Nice picture. I would have hated to start sailing in one direction not knowing if anything was ahead before I ran out of food or water.

A++ with the Keane choice. Ha.

http://busterp.multiply.com/journal/item/35/Picture_perfect_Rock_and_roll_Infinity.

aprillinda wrote on Feb 29

fantastic picture!
http://aprillinda.multiply.com/journal/item/16/Picture_Perfect_InFiNiTe

karen21445 wrote on Feb 29

Wonderful picture.

http://karen21445.multiply.com/journal/item/166/Picture_Perfect_-_INFINITE

ninakobie wrote on Feb 29

Lovely photo. well done.

http://ninakobie.multiply.com/journal/item/358

empressselena wrote on Feb 29

Very nice. Looks like the water should be moving. Great pic for the theme!

windin wrote on Feb 29

great blog entry, beautiful picture!

http://windin.multiply.com/journal/item/316?mark_read=windin:journal:316&replies_read=29

mjrohn wrote on Feb 29

Great shot and very well put information.
PS: I LOVE Keane!

Here's my take: Infinite

gaganawati wrote on Mar 1

Ohhhhhhhhhhhh it's so romantic, Lily. Great take on theme and hmmm ... feel like wanting to stay there with my hunny bunny. Mine is up dear,http://gaganawati.multiply.com/journal/item/15/Picture_Perfect_Friday_Infinite

stillwandering wrote on Mar 1

Lovely photo, and interesting post :)

lorasprouls wrote on Mar 1

I love sunset pictures! There is beauty in every one! Ok...I am computer illiterate...where do I find my p p link to post? Thanks.

cool2523danda wrote on Mar 1

Beautiful picture of the sunset.
http://cool2523danda.multiply.com/journal/item/69/PICTURE_PERFECT_Infinite

iluvsheldon wrote on Mar 1

Quite pretty!!
http://iluvsheldon.multiply.com/journal/item/253/Picture_Perfect_-_Infinite

tintalasia wrote on Mar 1

A beautiful photo. The information was fascinating too. I learnt a thing or two.

You're more than welcome to visit mine....
http://tintalasia.multiply.com/journal/item/144/Infinite_-_Picture_Perfect_Theme
Tint~

dreamzonforever wrote on Mar 1

HI lil, that's a beautiful sunset you have captured. Nice !
have a nice day !

http://dreamzonforever.multiply.com/journal/item/68/Picture_Perfect_-_Infinite

marsh7 wrote on Mar 2

nice shot,I do not take picture anymore but of cats,and work,landscaping

fotofriday wrote on Mar 2

Makes one want to find someone to love just to watch the sunset with them.

I'm amazed of how much of what the mathmaticians knew in the beginning we still use today but how far we've come with the knowledge.

http://fotofriday.multiply.com/journal/item/53/Picture_Perfect_theme_this_week_is_Infinite

fotofriday wrote on Mar 2

...and I like your music....

nicegirlnurse wrote on Mar 2

very nice! Lovely sunset...

http://nicegirlnurse.multiply.com/journal/item/257/Picture_Perfect_Infinite

alberto11v wrote on Mar 4

Beautiful shot and very informative. Thanks for the lovely view. Sorry for the delay in visiting yours. Thanks for viewing and commenting on mine.

http://alberto11v.multiply.com/journal/item/45/The_Possibilities_are_Infinite_-_Picture_Perfect

preacherman1962 wrote on Mar 10

lilangelwolf said

Nobody is sure who first deduced that the world is round.

Isaiah 40:22, "It is he that sitteth upon the circle of the earth, and the inhabitants thereof are as grasshoppers; that stretcheth out the heavens as a curtain, and spreadeth them out as a tent to dwell in:"

Somewhere around the reign of King Hezekiah (which began in 693 B.C.), God revealed to the world that the earth was round. I think God had it first ;-)

BTW, I enjoy the pics.

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