🔭 Hubble Tension

How rapidly is the universe expanding?

Current Best Estimate

72.04 kilometers per second per megaparsec
with 5 estimates

The Problem

The rate of the expansion of the universe is described as the value for H₀. Using different methods to determine H₀, we have a range of values:

  • 76.5 km/sec/Mpc ScienceDailyAstrobites
  • 73.3 kilometers per second per megaparsec
  • 73.2 ±1.3 km/sec/Mpc Adam Riess
  • 69.8 ±1.9 km/sec/Mpc Wendy Freedman
  • 67.4 ±0.5 km/sec/Mpc

So the number is somewhere between 67.0 and 77.0.

This web page provides the best way to resolve this conundrum, using Statistics!

The Science Behind This Approach

In 1906, statistician Francis Galton observed a competition to guess the weight of an ox at a country fair. Eight hundred people entered. Galton, being the kind of man he was, ran statistical tests on the numbers, and discovered that the average of all the guesses was almost exactly the weight of the ox.

This collective guess was not only better than the actual winner of the contest but also better than the guesses made by cattle experts at the fair.

So we are going to collect all the estimates input to this web page, average them and display the result.

Only one vote per person!

Enter a number between 67.0 and 77.0 with a single digit after the decimal point.