Optical Spectrum of a GalaxyF

lux

Recession velocity = 14387 km / sz = 0.0479

[O III]

H

H

Vesto SlipherVesto Slipher

Redshifted SpectraRedshifted Spectra

Edwin HubbleEdwin Hubble

The Original Hubble LawThe Original Hubble Law

Modern-Day Hubble LawModern-Day Hubble LawToday our best valuefor the Hubble constantis 70 +/- 5 km / s / Mpc.

Balloon AnalogyBalloon Analogy

Raisin-Bread AnalogyRaisin-Bread Analogy

Measuring the Ages of the OldestMeasuring the Ages of the OldestObjects in the UniverseObjects in the Universe

Color-Magnitude Diagram for a Globular Cluster

The age of the Universe is thought to be 13.7 Gyr.

The oldest globular clusters are about 12.6 Gyr old.

So things seem consistent!