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geoff: Let's expand our horizons
a bit wider
and look at
important findings that are
literally about space, time and
the cosmos as we know it.
You might remember Albert
Einstein theorized that as heavy
objects move through space and
time, they create ripple effects
in the fabric of our universe.
Now, an international team of
scientists have detected new
evidence of that.
Researchers found new signs of
gravitational waves -- waves
that are affected by huge
movements such as the collision
of black holes.
These are no small matters.
Our science correspondent, miles
o'brien, is here to break it
down.
What are gravitational waves?
>> They are ripples in the
fabric of time and Einstein
predicted them in 1915 and they
were verified by a ground-based
observatory in 2015.
What this latest discovery does
is prove they are more
ubiquitous and found at longer
wavelengths.
We are talking about a project
funded by the national science
foundation.
They have been working on this
for 15 years.
It is worth spending a couple
moments trying to understand
gravitational waves.
Jeffrey at Oregon state
university gave me a little
lesson we can sink our teeth
into.
>> One way to think about it is
if you think about space-time as
being jello, you have this, it's
a little bit more firm than a
regular jello, but you have
jello and the space in between
the sides of the jello gets
jiggled by these really massive
objects.
And so you can imagine, you
know, smack it in one side of a
big giant cube of jello and a
wave would pass through that
cube of jello.
And so things would compress and
expand as that perturbation
moves through the chunk of
jello.
Geoff: Help us understand the
scientific significance.
>> The laser beam observatory
from 2015 was like galileo
pointing his telescope at
Jupiter.
Now we are talking about much
more complicated and larger
telescopes, if you will, looking
at other wavelengths.
In this case a wavelength that
could be one light year long and
scientists have hypothesized
that gravitational waves would
have a background hum of them
but it was impossible to be
detected with any ground-based
observatory to see these ripples
at that magnitude.
Geoff: I am still -- I am struck
by the chaotic nature --
quixotic nature of the endeavor.
How did the scientists do the
work?
>> Imagine an observatory half
the size of our galaxy.
They took advantage of pulsars,
which are dead stars that are
very dense on the size of our
city.
They used pulsars, dead stars,
which have predictable rotating
begins and you can really set
your clock to it.
And if there is any change in
them you can infer something is
happening, in this case a great
educational -- a gravitational
waves that is changing.
So they were able to pick up
subtle changes and identify
where they infer to be these
gravitational waves.
Geoff: Do scientists know what
caused the ripples in the
gravity?
>> They think it might be super
massive black holes.
Space is a rough place and the
idea is they are taking out
these gravitational waves but
now I am officially getting in
deep for a history major so
let's go back to Jeff at Oregon
state university for his best
current hypothesis.
>> It's most likely from an
ensemble of millions of black
hole binaries, supermassive
gargantuan sized black holes
that live at the centers of
galaxies.
When two of them settle in after
a galaxy merger, that's when
they give off the gravitational
waves that we're looking for.
But we aren't there yet.
Geoff: So what is next?
What questions do the scientists
hope to answer?
>> They want to hone in on
individuals and help connect the
dots between these bouncing
around massive black holes and
long gravitational waves and in
so doing, create a cosmic
archaeology, understand more
about how the universe formed
and where it is going and doing
that by listening to the home of
the universe.
-- Hum of the universe.
Geoff: Miles o'brien, I always