By thinking of how to do it and showing evidence. muhaaa!
Dark energy.
Cosmology is defined as the science of the origin and development of the universe. an account or theory of the origin of the universe.
Cosmologists
Isaac Newton.
Einstein
what do scientist assume about the universe???
It is impossible to prove what was not witnessed. they only have theories because nothing else is atainable in that field of study. more information will become available but I don't think the universe is just going to hand us a VHS labeled "The Origin of the Universe"
The problem is - we can only speculate on the origin of the universe - based on our limited knowledge of the bit of space we live in ! There are literally billions of other galaxies out there - with hundreds of billions of suns and planets. There could be many other rules of physics & chemical elements that we just don't know of ! There's just no way of proving how the universe started (or whether this is the first ever universe !).
A cosmologist is a scientist who studies the universe as a whole, including its origin, evolution, and eventual fate. They use various tools such as mathematics, physics, and observation to understand the fundamental principles that govern the universe.
Please note this succint quote from Alan Guth: "The Big Bang theory says nothing about what banged, why it banged, or what happened before it banged." So, although Big Bang Cosmology is the only idea that explains certain undeniable facts about our Universe, it does not explain -- indeed, it doesn't even TRY to explain -- the origin of our Universe.
The known laws of chemistry and physics can explain the behavior and interactions of matter, but they do not provide a complete explanation for the origin of matter itself. The Big Bang theory is the leading scientific explanation for the origin of all matter in the universe, suggesting that all known elements were created in the early stages of the universe's evolution through processes such as nucleosynthesis.
Cosmology is the study of the origin and future of the universe.