The idea that the expantion of the universe may stop, then collapse, culminating in another “Big Bang” has intrigued me for many years.
the theory was discounted as the mass of the universe was foumd to be too small. With discovery of dark matter, & the discoverys of the Hubble Space Telescope, has this changed? As more & more matter is found, is it enough to approach that needed to indicate oscillation possible?
…Carl
Carl, I took a course at The Space Telescope Science Institute (STSI) at Johns Hopkins. This is where all the data from Hubble is being processed. There was hopes that Hubble would help answer this, but as it always goes, Hubble perhaps gives us more questions than answers! This topic is still hotly debated. In short, the jury is still out since the evidence is inconclusive.(Maybe we’ll get two weeks notice before the big “U” start collapsing?) 
“They’re coming to take me away ha-ha, ho-ho, hee-hee, to the funny farm where life is beautiful all the time… :)” - Napoleon IV
This subject came up in an article I was reading about neutrino mass. It seems that oscillating universe advocates are losing ground, the flat universe theory is seen as the highest probability. Even with massive neutrino’s there’s still a lot of mass to account for to get to a flat universe scenario. Dark matter, sounds ominous doesn’t it?
Here’s the article:
dark matter
The jury is still out on this one.
Visible matter accounts for only 10% of the mass required to close the Universe. But galactic movements show that there is “hidden” or dark matter out there. Whether there is enough to eventually collapse the Universe is unknown.
There is also evidence that neutrinos posess a tiny mass. Because there are so many of these critters, it may prove to be important.
The current thinking is that the Universe is balanced on a knife edge between open and closed.
Voted as the poster you’d most like to meet.
I demand a recount.
There was an intriguing sci fi short story whose premise was that oscillating Universes always expanded until some wise guy group of sentients starting trying to get their spacecraft velocities too close to c. Because of the resulting increase in mass, at that point the Universes always started to contract.