Countdown clock in Paris

Factual Questions
1

I saw this countdown clock in Paris last week. What was it counting, and why? It apparently started some 10.5 years ago, and presumably will be counting for 5 billion years. I think it was on the Palais de Tokyo, but I may be mistaken.

2

It is called the “Big Crunch Clock” and according to the article here:
http://images.google.com/imgres?imgurl=http://technabob.com/blog/wp-content/uploads/2008/03/gianni_motti_big_crunch_clock.jpg&imgrefurl=http://technabob.com/blog/2008/03/20/clock-counts-down-to-the-end-of-the-world/&usg=__g7yCW9hWzjOE1HkJPM5NEkZjG7A=&h=250&w=520&sz=13&hl=en&start=2&sig2=Cvd-60jh8GFyRSCoKt-_eQ&um=1&tbnid=NHeJw4LeYlZcPM:&tbnh=63&tbnw=131&prev=/images%3Fq%3D%2522Big%2BCrunch%2BClock%2522%26ndsp%3D20%26hl%3Den%26lr%3D%26sa%3DX%26um%3D1&ei=YdBnStbiG46TlAebkby2CQ
it is counting down 5 billion years until the Sun “blows up”.

As most Dopers know our Sun is not going to “blow up” but instead will swell to a distended Red Giant which will do one heck of a job incinerating the Earth.

Another problem with that article is its use of the term “Big Crunch”. I believe the Big Crunch is the opposite of the “Big Bang” and supposedly would occur when the Universe stopped expanding. At least according to the latest theory, the Big Crunch won’t occur and the Universe (like the Energizer™ bunny) will just keep going and going and going …

Well, now you know what the clock is counting.

3

It’s more extreme than that: The Big Crunch theory is that the Universe is massive enough to reverse its expansion and come back together into the kind of superdense state it was in immediately prior to the Big Bang, at which point it would become super-expansionary again and start a whole new Universe. It is, as you mentioned, out of favor due to recent observations.

4

Just the same, I’m going to hold off on those dinner reservations for the moment…

5

I reckon the clock probably will have stopped functioning before it reaches 0.

6

Is this independent of heat death?

7

Yeah, the sun’s going to expand in 5 billion years:

So we’d better move the clock before that happens if we want it to last the additional 5 billion until the big crunch (that may not happen).

8

Maybe they should call it “The Big Poof”.

9

That part is entirely speculation, and philosophical speculation, not scientific. The scientific model of the Big Crunch states that it’s a singularity past which no information can propagate, so for all practical purposes, it’s The End.

Heat death is a very fuzzy sort of concept. In a universe that doesn’t end any other way, you’ll eventually get heat death, but you can’t really pin down when it happens. In fact, even in a universe that does end some other way, you could still get something you might call heat death before the definitive End, if it takes long enough. By some standards, you could even argue that the heat death of our Universe occurred billions of years ago, and we’re just the last gasp of the death throes.

In addition to the Big Crunch, by the way, another definitive End scenario would be a Big Rip. That’s where whatever is that’s causing the acceleration of the Universe gets stronger with time, until eventually, it gets strong enough to rip everything, even subatomic particles, apart.