Anthropology Series In the Beginning How did the Universe begin? Don’t know!

What do we know? How the universe evolved from sec to now - 11 billion years later. From a size of cm to the present size How stars, solar systems & galaxies form Power source of stars There are 4 forces in nature that may be unified at high temps or early times

Steps to the beginning Cosmology – study of the whole cosmos - the very large High energy physics – search for the fundamental building blocks of nature – starts with the forces in nature and is the realm of the very small Never the twain shall meet?

Important numbers 11 billion years cm – “Planck length” sec – “Planck time” Speed of light 3x10 8 m/s. The speed limit of the universe

Force Laws Gravity Electricity and Magnetism Strong Nuclear Weak Nuclear

Gravity Force Distance behavior source of the force –cause? receiver - what can feel the force 1/r 2 gravitational charge - mass (m) F = Gm 1 m 2 /r 2 ATTRACTIVE ONLY - LARGE SCALE STRUCTURE/ STABILITY OF THE UNIVERSE

Electric force Distance source receiver 1/r 2 Electric charge (q) F= kq 1 q 2 /r 2 ATTRACTIVE AND REPULSIVE - STABILITY OF THE ATOMS/MOLECULES/MATTER

Strong Force Distance source receiver Scotch tape cm Strong charge - color ?????????????? ATTRACTIVE AND REPULSIVE STABILITY OF ATOMIC NUCLEUS

Weak Force Distance source receiver Scotch tape cm Weak charge - isospin ???????????????? Radio active decay - instability of matter

Range Gravity E & M Strong Weak Infinite Short cm Very short cm

Strength Strong E & M Weak Gravity

Mediators Strong E & M Weak Gravity Gluons Photons Weakons Gravitons Exchange particles (1949) vs. Action at a distance /field concept (19th century)

So Far Electron Proton Neutron The 4 mediators

The next step - the particle zoo Protons & neutrons have parts (quarks). Probing them at higher and higher energies yields more particles because of spontaneous creation using E = m c mesons 120 baryons Remember the 4 mediators Electron family

Mesons

Baryons

How many do you really need? mediators

I mean “really need” 1 Name - string 1 dimensional – length Size – cm The Planck length Opened or closed They vibrate to give all particle properties necessary-mass etc Unification of all forces!!

Continuous point theories All the interactions or forces so far have been described as space and time continuous even though other quantities of the theory are quantized.

Point particle theories

Gravity Singularities at t = 0 and center of black holes(point –particle theory) Quantum foam problem-from the uncertainty principle Assumes continuous warping of space-time

String theory

Super symmetric string theory (M) It is not a point particle theory like gravity and quantum mechanics Distances smaller than the Planck length are not accessible No singularities – Space-time is quantized Quantized geometry necessary Easy to talk about difficult to calculate Hopes to predict all particle masses & properties. Predicts 11 dimensions (10+1) Predicts many more particles than we currently observe

Summary - but not the whole story

More sources olog.htmhttp:// olog.htm /thesuperstring07http:// /thesuperstring07