Cosmology

Visualizing the Universe, one pixel at a time.

I   The Curvature of Space

Euclid of Alexandria
Born: about 325 BC
Died: about 265 BC in Alexandria, Egypt
Flat Space  (Shortest Distance is a straight Line)  1 parallel Line
August Ferdinand Möbius
Born: 17 Nov 1790 in Schulpforta, Saxony (now Germany)
Died: 26 Sept 1868 in Leipzig, Germany
Johann Carl Friedrich Gauss
Born: 30 April 1777 in Brunswick, Duchy of Brunswick (now Germany)
Died: 23 Feb 1855 in Göttingen, Hanover (now Germany)
Nikolai Ivanovich Lobachevsky
Born: 1 Dec 1792 in Nizhny Novgorod (was Gorky from 1932-1990), Russia
Died: 24 Feb 1856 in Kazan, Russia
1829 Negative Curved Space
Georg Friedrich Bernhard Riemann
Born: 17 Sept 1826 in Breselenz, Hanover (now Germany)
Died: 20 July 1866 in Selasca, Italy
1854 Positive Curved Space
Albert Einstein
Born: 14 March 1879 in Ulm, Württemberg, Germany
Died: 18 April 1955 in Princeton, New Jersey, USA
Special Theory of Relativity 1905
4th dimension "space-time"
C (speed of Light) is constant
E= mc2
General Theory of Relativity 1916
Key: acceleration = gravity (Elevator thought experiment)
Key: gravity warps/bends "space-time"
Field Equation

Forces   =  Geometry
Where Forces are --> (Pressure/density  + Velocity/motion of Particles)  + k (Constant)
Could have predicted that the Universe is expanding.

The Curvature of Space


k = +1  (Positive)
k = 0 k  = - 1 (Negative)

Riemann - Sphere
Euclid - Flat
Lobachevski - Hyperbolic Saddle Back
Sum of angles
 of Triangles
Gauss measured Mountains Peaks
Angle Sphere
> 180º  
Flat Triangle

= 180º
Hyper Triangle

< 180º
Circumference / R
Orange - Surface of Earth

Circum sphere

C <  2πR
Flat Surface
plane of paperCircle


C = 2πR
Pringle Potato Chip
Hyper circum

C > 2πR
Area / R
Area Sphere

< 4πR2
area-flat

= 4πR2
area hyper

> 4πR2
Volume / R
 < 4/3 π R3
 = 4/3 π R3
> 4/3 π R3
Boundaries
 Finite, Closed (Bounded)
 Infinite,  Open (no Boundaries)
 Infinite, Open,  No Boundaries,
Axiom
No Parallel Lines Though a point Only one Parallel line through a point
An Infinite number of parallel line through a single point


II Space-Time

Space Time

The Light Cone and Black Holes

Light Cones

stacks_image_104_1
img73


Non-Rotating Black Holes
The Schwarzschild Singularity

Rotating Black Holes
Kerr-Newmann, Black holes must "emit" something (faithful friend)

Basis for Cosmological Models

The Cosmological Principal
All modern cosmological models are based on the cosmological principle that our observational location in the universe is in no way unusual or special; on a large enough scale, the universe looks the same in all directions (isotropy) and from every location (homogeneity).
The red shift is a Doppler shift in electromagnetic radiation as it travels across expanding space. Expansion does not increase the size of the objects in space. It also allows for distant galaxies to recede from each other at speeds greater than the speed of light: local expansion is less than the speed of light, but expansion summed across great distances can collectively exceed the speed of light.
Assumes a "flat" spatial geometry, which means that the interior angles of a triangle defined by three beams of light will sum to 180°; space is defined by straight lines. Current values of key parameters imply that the universe is either flat or slightly open, the universe will and expand forever, and the expansion is accelerating.
Λ (Lambda), the cosmological constant currently associated with a vacuum energy or dark energy inherent in empty space. Explains the current accelerating expansion of space against the attractive (collapsing) effects of gravity. Currently, about 73% of the energy density of the present universe is estimated to be dark
A Cosmological Model must Explain:
the existence and structure of the cosmic microwave background (Big Bang -->superhot primordial soup)
the large scale structure of galaxy clusters (Inflation)
the distribution of hydrogen, helium, deuterium and lithium (nuecleosynthesis)
the accelerating expansion of the universe observed in the light from distant galaxies and supernovae (Dark Energy)
the formation of galaxies (Dark Matter)
The Composition of the Universe
Baryonic Matter: ~3% of the mass in the universe
This is ordinary matter composed of protons, neutrons, and electrons. It comprises gas, dust, stars, planets, people, etc.
Cold Dark Matter: ~23%
This is the “missing mass” of the universe. It comprises the dark matter halos that surround galaxies and galaxy clusters, and aids in the formation of structure in the universe. Dark matter is believed to be composed of weakly interacting massive particles or WIMPs.
Dark Energy: ~73%
Observations of distant supernovae suggest that the expansion of the universe is currently accelerating. This observation is backed up by the flatness of the universe as measured from the cosmic microwave background. Cosmologists believe that the acceleration may be caused by some kind of energy of the vacuum, possibly left over from inflation.
Cosmological Problems
Matter - Anti-Matter
Gravitational Waves
Hot Dark Matter
Find the Higgs Boson
556px-Standard_Model_of_Elementary_Particles

Leading Alternate - M Theory or String Theory

"Einstein comes along and says, space and time can warp and curve, that’s what gravity is. Now string theory comes along and says, yes, gravity, quantum mechanics, electromagnetism — all together in one package, but only if the universe has more dimensions than the ones that we see.” (Brian Greene)

The Official String Theory Web Site

world_line

History of the Universe Time Line

CMB_Timeline75