Dark Energy

Hiromi SuenagaCody TamuraPeriod 1

What is Dark Energy?

It affects the Universe’s expansion Other than that it is a total mystery Roughly 70 % of the universe is dark

energy

What is Dark Energy?

It could be a property of space Albert Einstein was the first person

to realize empty space is not really empty

Einstein’s Gravity Theory

One of his Gravity Theories that uses a cosmological constant makes a prediction that “empty space” can possess its own energy

Einstein Continued

As more space comes into existence, more dark energy would appear

This would accelerate the expansion of the Universe

No one really understands why the cosmological constant is there

Other Theories

Another theory utilizes the quantum theory of matter

Empty space is comprised of “virtual” particles that form and disappear continuously

Unfortunately, physicists tried to calculate the energy empty space would have, but was the solution was 10^120 times too large

Other Theories

Another theory is that dark energy could be a new kind of dynamical energy fluid or field

Another theory is that Einstein’s theory is incorrect

Dark energy would not only affect the expansion of the Universe, but would also affect normal matter in galaxies as well.

The Big Crunch and Chill

Before the dark energy was first observed, there were two models of the fate of the Universe

The Big Crunch

The Big Crunch theorizes that the Universe’s expansion would slow down until it finally begins to retract

Essentially, it would be the opposite of the Big Bang

The Big Chill

The Big Chill theorizes that the Universe would expand at a decelerating rate

Galaxies would drift extremely far apart from each other

All stars would die out and the Universe would be vast, cold, and dark

The Big Rip

With dark energy, the Universe’s expansion would accelerate until clusters of galaxies would tear apart

Galaxies would tear apart, until molecules and atoms would rip apart

It would be a more violent expansion than the Big Bang

The Big Rip

The Chandra X-ray Observatory has found evidence that the Big Rip is not in the Universe’s future

Observations have shown an increase in mass in galaxy clusters

An increase in mass or growth would be difficult with dark energy

Observations strengthen the idea that dark energy is the cosmological constant in Einstein’s theory

Video!

http://www.youtube.com/watch?v=JaImVFRpOR8

Works Cited

Atkinson, Nancy. "No “Big Rip” in Our Future: Chandra Provides Insights Into Dark Energy." Universe Today. 16 Dec. 2008. Web. 17 Apr. 2011. <http://www.universetoday.com/22382/no-big-rip-in-our-future-chandra-provides-insights-into-dark-energy/>.

"Dark Energy." Large Synoptic Survey Telescope. Web. 17 Apr. 2011. <http://www.lsst.org/lsst/public/dark_energy>.

"Dark Energy, Dark Matter." NASA Science. Web. 17 Apr. 2011. <http://science.nasa.gov/astrophysics/focus-areas/what-is-dark-energy/>.

"HubbleSite - Dark Energy - Fate of the Universe." HubbleSite - Out of the Ordinary...out of This World. Web. 17 Apr. 2011. <http://hubblesite.org/hubble_discoveries/dark_energy/de-fate_of_the_universe.php>.

Moskowitz, Clara. "What Is Dark Energy? | Space.com." Space, NASA Information & News | Outer Space Flight Videos & Pictures | Astronomy, Solar System Images | Space.com. Web. 17 Apr. 2011. <http://www.space.com/6619-dark-energy.html>.