Which period of time is correct?Google wrote: For more than 100 years, astronomers have been observing a curious star located some 190 light years away from Earth in the constellation Libra. It rapidly journeys across the sky at 800,000 mph (1.3 million kilometres per hour). But more interesting than that, HD 140283 — or Methuselah as it's commonly known — is also one of the universe's oldest known stars. In 2000, scientists sought to date the star using observations via the European Space Agency's (ESA) Hipparcos satellite, which estimated an age of 16 billion years old. Such a figure was rather mind-blowing and also pretty baffling.
Will the universe die?
The theory that the universe will stop expanding and deflate until there is a Big Crash has largely been disregarded now.
The main theory now is that the universe will continue to expand until forces on sub-atomic particles weaken. After many billions of years planets will drift away from their suns, and eventually suns will drift away from galaxies and galaxies will drift apart as gravity has little effect. After many trillions of years the forces that hold sub-atomic particles together will weaken until they drift apart. After many trillion, trillion years the distance of a particle from any other particle will be so great that effectively there will be only one or two in the volume of the universe that we can see. As sub-atomic particles can be considered waves, perhaps the waves then weak to nothing like waves on a pond. After further expansion there will be essentially nothing in the universe at all.
What happens to time and space itself with virtually nothing in it able to interact with anything else? We don't know.
The energy of the universe cannot be increased or destroyed, so presumably energy is still there in virtually empty space and incapable of doing anything.
