News for hackers. Stuff that matters.

A comment on Can rotation solve the Hubble Puzzle?. Parent comment

Re:Can rotation solve the Hubble Puzzle? by nodfyr on Tuesday April 22, 2025 @08:26AM (#43761321)
That would imply a preferred direction in the universe (the axis of rotation) and thus anisotropy.

There are stringent constraints on anisotropy from the cosmic microwave background.

In particular, one can use the Doppler effect to check whether the CMB dipole is compatible with our velocity with respect to the CMB frame.

[ Parent | on HN ]
Re:Can rotation solve the Hubble Puzzle? by gitaarik on Wednesday April 23, 2025 @01:55AM (#43769045)
Well, the universe has an axis, found in the CMB:

https://en.m.wikipedia.org/wiki/Axis_of_evil_(cosmology)

[ Parent | on HN ]
Re:Can rotation solve the Hubble Puzzle? by jfengel on Wednesday April 23, 2025 @04:34PM (#43776359)
The article says right up front that the universe does not have an axis:

However, a 2016 study compared isotropic and anisotropic cosmological models against WMAP and Planck data and found no evidence for anisotropy.

[ Parent | on HN ]
Re:Can rotation solve the Hubble Puzzle? by gitaarik on Thursday April 24, 2025 @06:59PM (#43788453)
That was only one observation, most of the observations do indicate there is an axis
[ Parent | on HN ]