For the first time ever we’ve been able to discover light coming from an object
that has also produced gravitational waves and this is a really significant discovery.
So what we’ve detected are two objects which we call Neutron Stars colliding.
These are objects that we’ve know about for a long time now in astrophysics,
they’re extraordinary dense stars, stars that have a mass something like the mass of the sun
but compressed into a ball just a few miles across and so those objects have very strong gravity
and when you crash two of them together as happened in this case
it creates ripples that propagate through the universe.
And if we want to understand our place in the universe,
we want to understand how common planets like Earth are
we need to understand where the basic building blocks came from.
The gravitational waves really tell us what the system was that collided.
It tells us the masses of the neutron stars and how they came together
and to some extent what was leftover at the end.
The electromagnetic view tells us about the explosion
and what material was thrown out in the process of the collision and how that material behaved,
how it expanded, the kind of light it put out,
the amount of gold and heavy elements that were in that cloud of expanding debris
is something we can only learn from the electromagnetic side.
And now we’ve got measurements showing that these heavy chemicals were newly created
in the aftermath of two merging neutron stars in this event that we call a Kilonova
as the radiation from that synthesis takes place.
And so if that idea is right it suggests that the Earth and the heavy elements that we find in the Earth
must have formed from a cloud of gas that itself had been enriched with those elements
by a merger like this but billion and billions of years ago.
So to detect one of these in such exquisite detail with gravitational waves
and light across the whole electromagnetic spectrum from gamma rays through x-rays, ultra-violet,
optical light that we can see with our eyes, infer red and down into and down into the radio wave length
changes the way we think.
So it really is giving us a much richer and more complete picture by putting the two sides together.
