If you're puzzled by what dark energy is, you're in good company.
This new understanding of processes on Europa would not have been possible without the foundation of the last 20 years of observations over Earth's ice sheets and floating ice shelves.
From our point of view, the most exciting thing would be if we discovered something really fundamental in our understanding was just off a bit - and that now we have a chance to revisit it.
As a scientist, you feel a sense of team spirit for your country but you also have a sense of team spirit for the international community.
It seemed like my favourite kind of job - a wonderful chance to ask something absolutely fundamental: the fate of the Universe and whether the Universe was infinite or not.
I was one of those kids who always thought that we should know how the world works around us.
If you ask almost any of them, 'Do you stand behind your theory? Is this the answer?' I think almost everyone would say, 'No, no, no. I'm just trying to expand the range of possibilities.' We really don't know what's going on.
What we were seeing was a little bit like throwing the apple up in the air and seeing it blast off into space.
I will say that growing up as a kid in an urban environment and having lived in cities all my life, the one achievement that everyone can look forward to is getting the perfect parking spot.
You want your mind to be boggled. That is a pleasure in and of itself. And it's more a pleasure if it's boggled by something that you can then demonstrate is really, really true.
We have a remarkably complete picture in many ways - and it could be that we're not accounting for something that's almost three-quarters of the entire universe.
I tend not to dwell too much on ultimates.
Probably the single most important thing about the Nobel Prize for most people is whether they get the coveted parking space on campus.
For almost a century, the Universe has been known to be expanding as a consequence of the Big Bang about 14 billion years ago. However, the discovery that this expansion is accelerating is astounding. If the expansion will continue to speed up, the Universe will end in ice.
You might expect gravity would slow it down, but it's just expanding faster and faster.
This is the kind of discovery that resonates.
There are still so many questions to answer. When you look at any part of the universe, you have to feel humbled.
So it's possible that someday, by understanding a little bit more about how the world works, it will come back to help us in some other way that will be surprising.
It's an unusual opportunity, a chance for so many people to share in the excitement and the fun of the fact that we may be on to hints as to what the Universe is made out of. I guess the whole point of a prize like this is to be able to get that out into the community.
The original project began because we know the universe is expanding. Everybody had assumed that gravity would slow down the expansion of the universe and everything would come to a halt and collapse. The big surprise was it was actually speeding up.
