How Do We Know The Universe Is Accelerating?

Опубликовано 26 апреля 2017, 12:30

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Aatish Bhatia helped write this video! A big thanks for his help! Here's his blog: empiricalzeal.com

The universe is expanding – this we know from looking at red shifts of distant galaxies – but the acceleration of the universe's expansion is harder to measure. It requires measuring the change of recession velocity over time, and it's done by comparing Type Ia supernovas as standard candles at different distances, which is how we know the universe is accelerating!

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REFERENCES

Type Ia supernovae
hyperphysics.phy-astr.gsu.edu/...
en.wikipedia.org/wiki/Type_Ia_...

Luminosity Distance
en.wikipedia.org/wiki/Luminosi...

Hubble diagram for type Ia supernovas (relatively close to earth): pnas.org/content/101/1/8/F3.ex...
astronomy.ohio-state.edu/~thom...

Straightforward references:
Ryan Foley talking about WFIRST & Dark Energy
youtu.be/BhOAwXYKdmw?t=23m
Dark Energy FAQ:
preposterousuniverse.com/blog/...
Why does dark energy make the universe accelerate?
preposterousuniverse.com/blog/...
David Spergel on dark matter & WFIRST
tvr2c.com/2016/06/01/53116-sho...

Slightly-technical references:
Permlutter article (old article but quite well explained & goes into future directions near the end)
supernova.lbl.gov/PDFs/Physics...

Technical references:
Mukhanov’s Physical Cosmology
astro.caltech.edu/~george/ay21...
Nobel Prize Summary
nobelprize.org/nobel_prizes/ph...
Cosmological redshift
en.wikipedia.org/wiki/Redshift...

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