In a galaxy far away,
gravity didn't quite work
the way it does on Earth.
And the speed at which everything moved
was really weird too.
Maybe, some places in our vast Universe
just don't abide by our laws of physics.
And if that was true,
If you stargaze long enough,
and I mean really long,
you might notice that the galaxies
are getting further apart.
Here's the deal with our Universe.
For all we know, it started
as a single point,
and it's been expanding ever since the Big Bang.
Although gravity is supposed to
crash things back together,
the galaxies keep moving away from each other,
driven by a mysterious,
hypothetical force we call dark energy.
And it's speeding up.
A few studies have shown that
some places in the Universe
aren't expanding the way we expect them to,
making our understanding
of the principle laws of physics
So what if everything we know
about the Universe is wrong?
If every corner of the Universe turned out to be different,
it would crash the cosmological principle
that explains how the Universe works.
We see the Universe as isotropic, or uniform.
We expect that stars, planets, and galaxies
in the furthest corner of the Universe
behave exactly like they do
here in the Milky Way galaxy.
A non-uniform Universe would be anisotropic.
And all that would mean is that
the fundamental laws of physics
aren't universal after all.
Some distant places in the Universe
could have totally different cosmological constants,
like the speed of light.
In our corner of the Universe,
light travels at 300,000 km/s (186,000 mi/s).
And nothing can travel faster than light.
But in an anisotropic Universe,
the speed of light could be different.
In some places, it might be faster,
allowing some alien civilizations
to travel very quickly across their galactic neighborhood.
But in other places, the speed of light might be slower,
making everything in that part of the Universe
move much, much slower.
Gravity could work differently across the Universe too.
There could be planets out there, where gravity
would be strongest on the objects with smaller masses.
And maybe, just maybe, those planets
would have stars orbiting them,
and not the other way around.
Maybe some places in the Universe would have
gravity that changes, depending on the time of day.
And maybe the alien species
inhabiting such worlds would have
bodies that adapt to those changing gravitational conditions.
But none of this would change
how things work here on Earth.
We determine the distance between objects in the Universe
based on these principles as we know them.
If the Universe isn't uniform,
we could be wrong about
how far the Andromeda galaxy is from us,
and how soon it will collide
with our galaxy, the Milky Way.
We could have miscalculated how long it would take
to go to Proxima Centauri.
We could be wrong about the age of the Universe too.
If the Universe isn't the same everywhere,
then it might make space exploration easier for us.
We'd just need to understand all the different
principles of the Universe,
and use them to our advantage.
But that could also make interstellar travel more difficult,
leaving us limited to only exploring
and colonizing our own Solar System.
But hey, that could be fun too,
as long as you know how to survive
on the planets we've yet to colonize.
And we have a show for you about just that,
to help you survive whatever awaits you.