Berkhof's theorem in general relativity states that a spherically symmetric region is unaffected by the expansion of space outside it

Overview Debates Related claims Topics

The black hole information paradox persists even when considering that the black hole evaporates

Even in an evaporating black hole, it is possible to construct world lines that hit the singularity before the black hole evaporates

In an evaporating black hole, there is a sense in which no true event horizon exists

In general relativity's Big Bang model, space is not expanding into anything

In an evaporating black hole, information that goes in eventually comes out in the form of Hawking radiation

Cosmologists study the universe as a whole, typically at scales of galaxy size and larger

Self-locating uncertainty can be used to frame credence in different physical theories, like dark matter being WIMPs or axions

The Boltzmann brain idea posits that in a randomly fluctuating thermal system, intelligent observers will eventually form

Early universe cosmologists often have a similar toolkit and training to high energy particle physicists

The force of gravity holds together structures like galaxies and clusters, preventing them from expanding with the universe

A Boltzmann brain observer would most likely fluctuate into existence surrounded by thermal equilibrium, not an ordered universe

The total computational capacity of the universe is bounded by the number of particles and the speed of light

The universe can be infinitely large and still be expanding

There is no scientific consensus on whether the period of exponential expansion before the Big Bang was eternal

The theory of inflation is the most widely accepted theory of what happened before the Big Bang

The Big Bang happened everywhere in space simultaneously, not at a single point

The Big Bang is defined as the time when the universe was very hot and dense

The age of the universe is measured as 13.798 billion years, plus or minus 0.035 billion years

Quantum mechanics is the best current theory of physics, except for Einstein's theory of general relativity for gravity

The observable universe contains 350 billion galaxies