Respected quantum physicist Jim Al-Khalili presents a two part documentary series about the start and the demise of our universe titled “The Beginning and End of the Universe”. We know that the universe is expanding, this was first observed by Edwin Hubble who actually saw it accelerating in size which presented the possibility of the universe starting from a “point”. Today we know this as the big bang theory and while it’s a theory since it can not be directly observed in practical terms we know the big bang theory to be true with almost certainly. The first episode of The Beginning and End of the Universe explores our uncovering of the origins of the universe which is regarded as humankind's greatest intellectual achievement.
The end of the Universe is still not clear to many scientists, however for at least the last 30 years it has been largely agreed upon that there will be one. Either the universe will contiune to expand until particles become so spread apart that they can no longer interact with each other anymore. This is know as the “dark age” of the universe. The other option is “the big crunch” which as the name suggests the universe falling back in on itself towards another big bang.