Is there a beginning?

The Origin of the UniverseThe Origin of the Universe

Creation From Something Order out of Chaos Creation from Nothing

Yes

Eternal Existence Rhythmic Universe

No

Is there a beginning?

From “The Dancing Universe” by M. Gleiser [page 303].

“Eternal Existence”In the Steady-State Theory, new galaxies must form in

between old ones. Otherwise, space will grow more and more empty as the Universe expands, thereby changing its appearance, a violation of the steady state premise.

Copyright ©1999 The McGraw-Hill Companies.

Proposed by Bondi, Gold, and Hoyle in 1948.

•Universe Does Change

•Quasars

•Cosmic BackgroundPenzias and Wilson with their historic horned antenna at Crawford Hill, N.J.

A map of the brightness of the cosmic microwave background made by the cosmic background explorer

(COBE) satellite. Notice the patchiness of the brightness. Each pink patch may represent a 'lump' of matter from which

groups of galaxies ultimately grew. The patches were approximately one half billion light years across when they

emitted the radiation.

(NASA's Goddard Space Flight Center and the COBE Science Working Group.)

Creation From SomethingCreation From SomethingBefore 10-43 sec we know essentially nothing

Planck timeCould lead to creation from nothing???

Between 10-35 and 10-6 sec there was equilibrium between particles, antiparticles and photonsBy the age of ten minutes, the Universe had completed its primordial nucleosynthesis

Early Universe hot and denseLight elements were formedHelium about 25%Supports Big Bang Theory

At Birth (Big Bang) Universe mainly radiationSome radiation

changes to matter via E = mc2

Forms quarks, anti-quarks, electrons and positrons

Matter and Radiation in the Early UniverseMatter and Radiation in the Early Universe

Expansion cools and some matter stabilizes as quarks turn into protons and neutrons.

Cooling continues with expansion.

Some protons fuse into helium, creating uniformity of H/He ratio...

Cooling allows electrons to attach to nuclei to form atoms.

Cooling allows gas to form clouds which turn into galaxies.

Expansion continues - NOW

Successes and Failures of the BigSuccesses and Failures of the Big--BangBang

Explains cosmic background radiationExplains proportions of lightest elementsExplains expansion

Can’t explain homogeneity and isotropyCan’t explain why all directions = 2.726 KCan’t explain Flat Universe

Copyright ©1999 The McGraw-Hill Companies.

InflationInflationThe INFLATION model is a theory that proposes a

extremely rapid and enormous expansion of the universe in the first instants after the Big Bang.

Between 10-43 and 10-35 seconds after the Big Band the formation of elementary particles (quarks, antiquarks, leptons, antileptons) produced an enormous amount of energy that caused the universe to expand tremendously.

The universe then "inflated" and any irregularities in it were greatly smoothed.

In the inflationary model, between 10-35 and 10-33

seconds, the universe doubles in size every 10-35 s

By the end of inflation then, space-time is 1050 times bigger

Regions of this universe are “supercool” and nucleate away from the rest

Perhaps our universe is one of these separate regions

A sketch depicting bubbles that might become separate universes forming in an inflating universe.

Copyright ©1999 The McGraw-Hill Companies.

The Newest TheoryThe Newest TheorySteinhardt and Turok picture two flat, parallel, four-dimensional spacetimes — our familiar universe and a separate "mirror" version — lying close together in a larger, fifth dimension. This outer dimension is inaccessible to us, the same way that two-dimensional creatures living in a sheet of paper could not see into the third dimension above and below their plane. Mathematicians have a word for spaces embedded in higher dimensions: "branes," analogous to 2-D membranes in our 3-D world.

The two branes move together and apart in cycles perhaps many trillions of years long. When they come together and intersect, the energy of their collision fills each with the matter and energy of a new Big Bang. As they move apart, their internal contents disperse over billions of years, as observed. Eventually they become very nearly empty and their motion apart stagnates, setting the stage for them torecollide and set off a new Big Bang creation.

See http://skyandtelescope.com/news/current/article_592_1.asp

The cyclic-universe theory and the inflation theory may be testable fairly soon. Inflation predicts that the cosmic microwave background radiation should show certain, specific patterns of polarization. The cyclic-universe version of the Big Bang would leave different patterns.

The European Space Agency‘s Planck Satellite due for launch around 2007, is designed to make just such measurements. If it proves sensitive enough, Planck may declare a clear winner in the showdown of inflation versus the cyclic universe before the decade is out.

Is there a beginning?

THE END