Physical limits and the long-term future (with Anders Sandberg)
Clearer Thinking with Spencer Greenberg
Energy Disappears in an Expanding Universe
In an expanding universe, the traditional concepts of time invariance and energy conservation become compromised. Unlike in special relativity where space-time is flat and symmetrical, general relativity presents a lumpy space-time influenced by mass. This curvature, along with expansion, results in non-equivalent reference frames that affect how we compare the universe at different times. Consequently, energy appears to disappear, exemplified by redshift phenomena where long wavelength light, traveling vast distances, shows reduced energy, akin to the Doppler effect. Observations of distant astronomical events like quasars and supernovae illustrate this energy loss, challenging the notion of global energy conservation in the context of an expanding universe.
