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What is the curvature of our physical space, according to the latest experimental data? I've found it somewhat difficult to find a definitive answer to the question, because the spacetime curvature comes up in Google instead. For some reason I always thought we live in a hyperbolic space and that it's confirmed by some evidence provided by astronomic measurements (see, e.g., Lobachevsky's star triangle experiment).

Qmechanic
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Atas
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1 Answers1

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The latest data is from the Planck satellite, and you can find the results in this 15MB PDF.

The matter and dark energy densities are;

$$\begin{align} \Omega_M &= 0.315 \pm 0.017 \\ \Omega\Lambda &= 0.686 \pm 0.020 \end{align}$$

So we get a total density of $\Omega = 1.001 \pm 0.026$. So within the 2.6% experimental error spacetime is flat.

John Rennie
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  • This Nature News article mentions a speculative model in which there could be an extra quantum field relevant to cosmology besides the speculated "inflaton" field, labeled the "curvaton" field, which could account for a small observed asymmetry in the temperature of the cosmic microwave background radiation, and which would imply a small negative curvature to space. They say the deviations in the CMBR predicted by the model "could be small enough to fit within the limits imposed by measurements with the Planck satellite". – Hypnosifl Apr 10 '15 at 17:45
  • All good fun of course. And I do wonder if the evidence against a homogeneous universe is nearing the paradigm shift tipping point. Still, for now I would be cautious about the wilder fantasies of theoretical physicists :-) – John Rennie Apr 10 '15 at 18:14
  • Paradigm shift? I don't know of any credible evidence against homogeneity. Just lots of pet theories looking for zebras (new physics!) among horses (galaxy clusters). –  Apr 10 '15 at 19:47
  • Within 2.6% experimental error spacetime has a radius of curvature $r > r_0$ with some huge $r_0$ ;) – image357 Apr 10 '15 at 19:53