Universe as a system
Posted: Sun Jan 22, 2017 6:39 pm
This might be a stupid question but how is the universe an isolated system?
The energy of an isolated system must remain constant because no matter or heat can be transferred and the system cannot be physically changed (ΔV = 0)
Since the Universe is expanding, how is it an isolated system?
Re: Universe as a system [ENDORSED]
Posted: Sun Jan 22, 2017 6:50 pm
The Universe might be expanding, but it is still an isolated system because it can neither gain nor lose both matter and energy. We can see this idea in the first law of thermodynamics that states energy can be transformed and transferred, but not gained or destroyed. Additionally, the expansion of the universe can also be looked at from the sense of the second law of thermodynamics that states that systems tend towards entropy or disorder. The universe is expanding and increasing its entropy, but it is not gaining or losing energy or matter in the process.
Re: Universe as a system
Posted: Sun Jan 22, 2017 7:13 pm
The universe is a closed system basically bc things cannot disappear into thin air.
We cannot gain or lose Energy in the universe.
Conservation of Energy!