The Planck satellite's mission up in space (7/8)

Uploaded by TheOpenUniversity on 03.06.2009

I'm Dave Clements.
I'm a lecturer in astrophysics at the Imperial College in London.
I'm involved in various of the Herschel and Planck projects,
but you've asked me to talk about Planck, so...
Planck's a microwave background survey mission.
Its aim is to map out the entire sky, at nine different wavelengths,
ranging from 350 microns and going to 30 gigahertz at the radio end.
This will allow us to look at the small fluctuations,
left in the microwave background by the physics in the early universe,
just as the universe was cooling,
so that light could pass freely,
from where photons decoupled from the general plasma,
and they can free-stream to us.
So, what we're seeing with, in the microwave background,
are photons that have not interacted with any matter,
since 100,000 years or so after the Big Bang.
So, this is the oldest light in the universe that we're seeing.
And the little ripples you can find in the microwave background,
are the seeds of all of the large-scale structure,
all of the structure that we see today.
So, if it wasn't for these little ripples, the earth wouldn't exist,
the sun wouldn't exist, our galaxy wouldn't exist and we wouldn't exist,
so, this is really fundamental stuff.
We're looking at the physics, and trying to understand the physics,
that produces us, and that further backwards,
is behind the Big Bang, and why the universe is here at all.
How did it feel when you were watching the launch,
and when you knew everything was OK?
Once everything was OK, it was a great relief,
but up until then, you're expecting... at least I am,
maybe I just look at things this way, I'm expecting things to go wrong.
Many years ago, the first Arianne 5 launch, in '95 or '96,
I watched that live and that was the one that blew up.
So, I think the ghosts of that,
may now finally have been exorcised from my point of view.
I've seen this one, which I'm very directly involved with,
I saw the XMM launch,
that was a few years after the first Arianne 5 launch -
that went fine, so I feel a lot better about Ariannes now.