#2516: Hubble Tension

XKCD comic, described below.
Transcript

[Cueball and Ponytail are walking to the right. Ponytail has her palm raised.]

Ponytail: There are three main estimates of the universe's expansion rate and they all disagree.

[They keeping walking to the right.]

Ponytail: Measurements of star distances suggest the universe is expanding at 73 km/s/megaparsec.

[They are still walking to the right.]

Ponytail: Measurements of the cosmic microwave background suggest it's expanding at 68 km/s/megaparsec.

[They continue walking to the right. Ponytail points towards Dave who replies from off-panel to the right.]

Ponytail: And Dave, who has a radar gun, says it's expanding at 85 mph in all directions.

Dave (off-panel): Those galaxies are really booking it!

Ponytail: Thanks, Dave.


(Sourced from explainxkcd.com)

Title text:Oh, wait, I might've had it set to kph instead of mph. But that would make the discrepancy even wider!


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