Carl Sagan on natural laws/constellations

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Carl Sagan on natural laws/constellations

��� Carl Sagan on natural laws/constellations
The desire to be connected
with the cosmos...
...reflects a profound reality...
...for we are connected.
Not in the trivial ways that the
pseudo-science of astrology promises...
...but in the deepest ways.
Our little planet is
under the influence of a star.
The sun warms us. It drives the weather.

(We now know that not all life depends on sunlight.)
It sustains all living things.
(Life may even have begun in the sunless depths.)
Four billion years ago,
it brought forth life on Earth.
But our sun...
...is only one of
a billion trillion stars...
...within the observable universe.
And those countless suns

all obey natural laws...
...some of which are
already known to us.
How did we discover
that there are such laws?
If we lived on a planet
where nothing ever changed...
...there wouldn't be much to do.
There'd be nothing to figure out.
There'd be no impetus for science.

And if we lived in
an unpredictable world...
...where things changed
in random or complex ways...
...we wouldn't be able
to figure things out.
And again, there'd be
no such thing as science.
But we live in
an in-between universe...

...where things change, all right...
...but according to patterns, rules...
...or as we call them,
laws of nature.
If I throw a stick up in the air...
...it always falls down.
If the sun sets in the west...
...it always rises again
the next morning in the east.
And so, it's possible

to figure things out.
We can do science, and with it
we can improve our lives.
Human beings are good
at understanding the world.
We always have been.
We were able to hunt game
or build fires...
...only because we had
figured something out.

There once was a time...
...before television...
...before motion pictures,
before radio, before books.
The greatest part of human existence
was spent in such a time.
And then over the dying embers
of the campfire...
...on a moonless night...
...we watched the stars.

The night sky is interesting.
There are patterns there.
If you look closely,
you can see pictures.
One of the easiest constellations
to recognize...
...lies in the northern skies.
In North America,
it's called the Big Dipper.
The French have a similar idea.

They call it La Casserole.
'The casserole.'
In medieval England,
the same pattern of stars...
...reminded people of
a simple wooden plow.
The ancient Chinese had
a more sophisticated notion.
To them these stars carried...
...the celestial bureaucrat on

his rounds about the sky...
...seated on the clouds
and accompanied...
...by his eternally
hopeful petitioners.
The people of northern Europe
imagined another pattern.
To them it was
Charles' Wain, or wagon.
A medieval cart.

But other cultures saw these seven
stars as part of a larger picture.
It was the tail of a great bear...
...which the ancient Greeks
and Native Americans saw...
...instead of the handle of a dipper.
But the most imaginative interpretation
of this larger group of stars...
...was that of the ancient Egyptians.
They made out a curious procession

of a bull and a reclining man...
...followed by a strolling hippopotamus
with a crocodile on its back.
What a marvelous diversity
in the images various cultures saw...
...in this particular constellation.
But the same is true
for all the other constellations.
Some people think these things
are really in the night sky...

...but we put these pictures
there ourselves.
We were hunter folk...
...so we put hunters and dogs...
...lions and young women
up in the skies.
All manner of things
of interest to us.
When 17th century European sailors
first saw the southern skies...

...they put all sorts of things
of 17th century interest up there.
Microscopes and telescopes,
compasses...
...and the sterns of ships.
If the constellations had been
named in the 20th century...
...I suppose we'd put there
refrigerators and bicycles...
...rock stars,

maybe even mushroom clouds.
A new set of human hopes and fears...
...placed among the stars.
But there's more to the stars
than just pictures.
For example, stars always
rise in the east...
...and always set in the west...
...taking the whole night to cross
the sky if they pass overhead.

There are different constellations
in different seasons.
The same constellations always rise
at, say, the beginning of autumn.
It never happens that
a new constellation...
...suddenly appears out of the east,
one that you never saw before.
There's a regularity, a permanence...
...a predictability about the stars.
In a way, they're almost comforting.
http://www.youtube.com/watch?v=Iviw7umSazo���

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