分类目录归档：universe
All the material objects around you
are composed of submicroscopic units
we call molecules.
And molecules in turn are composed
of individual atoms.
Molecules frequently break apart
and then form new m
How much can we really know about the universe beyond our galaxy?
The Hubble Telescope has enabled us to see
objects in space as far 13,000,000,000 light years away.
But this still doesn't give us t
Astronomers have discovered thousands of planets orbiting stars other than the Sun.
They come in all sizes,
at different orbital distances from their stars.
The closest of them are trillions of miles
In the winter of 1995,
scientists pointed the Hubble Telescope at an area of the sky near the Big Dipper,
a spot that was dark and out of the way of light pollution from surrounding stars.
The locatio
The universe began its cosmic life in a big bang
nearly fourteen billion years ago,
and has been expanding ever since.
But what is it expanding into?
That's a complicated question.
Here's why:
Einst
If you were to take any everyday object, say a coffee cup, and break it in half,
then in half again, and keep carrying on, where would you end up?
Could you keep on going forever?
Or would you find
We know about our universe’s past:
the Big Bang theory predicts that all matter, time, and space
began in an incredibly tiny, compact state about 14 billion years ago.
And we know about the present:
[Laughter]
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hello
anyone there
i need a bit of advice
oh there you are how convenient
you see in three months from now
i will become a father for the first
time
panic so what is
in y
through the history of humanity we have
been fascinated by our skies
across different civilizations we have
followed the motion of the stars
the planets their moons and much much
more
all of these inq
let's start with the thought experiment
imagine that our universe is infinite
and expands
with particles distributed roughly
equally around the space
what will such a universe be like first
because th