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Einstein and the big questions – some answers?

Einstein and the big questions – some answers?. Morelia, MEXICO 2006 R. Delbourgo, November. What big questions?. What is the fate of the universe? How did the universe begin? What is the universe made of? Where is the antimatter in the universe?

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Einstein and the big questions – some answers?

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  1. Einstein and the big questions – some answers? Morelia, MEXICO 2006 R. Delbourgo, November

  2. What big questions? • What is the fate of the universe? • How did the universe begin? • What is the universe made of? • Where is the antimatter in the universe? • Why are there only 3 “generations” of particles? • Why are there no magnetic charges? • Is there another basic unit besides h & c? GN? • Can one predict the 20 or so SM parameters? • Are relativity & CPT conservation correct? • Can one unify gravity with quantum theory?

  3. Current ideas on the universe’s fate • The universe is expanding at an ever increasing rate (based on assumptions about supernovas)! So is there a cosmological constant?

  4. Einstein and the early universe There was NOTHING before the big bang, no space, no time, zilch, i.e. it had zero dimensions. Einstein on the early universe: “One may not assume the validity of the equations for very high density of field and matter, and one may not conclude that the beginning of expansion must mean a singularity in the mathematical sense”

  5. What is the universe made of? • 75% vacuum energy • 20% dark matter (non-baryonic = machos, wimps, neutrinos, axions,..) • 5% mostly visible matter (baryonic = known particles, atoms) etc.

  6. Fate of the universe Supernova data => accelerating expansion corresponds to a -ve pressure or an Einstein “cosmological constant” of Λ = 10-52 m-2. Compare with known scales: Nuclear size ~ 10-15 m Human size ~ 1 m Milky Way galaxy ~ 1022 m Size of visible universe ~ 1026 m Einstein on the size of the universe: “Only two things are infinite: the universe and human stupidity. And I’m not sure about the former.”

  7. The scale of things

  8. Einstein and Research Einstein on research: “If we knew what we were doing, it would not be called research, would it?”

  9. Einstein and Relativity • Overturned our notions of space and especially time, through the special theory of relativity. Einstein on the 4-dimensional Minkowskian description: “Since the mathematicians have invaded the theory of relativity, I do not understand it myself any more.”

  10. Connected curvature of space-time with the presence of matter-energy through his general theory of relativity, e.g. the bending of light. Einstein on the happiest thought of his life, namely discovering the equivalence principle: “I was sitting in a chair in the patent office when all of a sudden a thought occurred to me: If a person falls freely he will not feel his own weight. I was startled and this simple thought made a deep impression on me. It impelled me towards a theory of gravitation.”

  11. Einstein and astronomy Started off the science of cosmology, introducing the cosmological constant (his “biggest blunder”). Einstein to Weyl: “If there is no quasistatic world, then away with the cosmological term.” “Anyone who has never made a mistake has never tried anything new.”

  12. Predicted gravitational lensing, seen for some galaxies and now used (as “microlensing”) to detect stellar planets.

  13. Predicted the existence of gravitational radiation from changing non-spherical systems (Einstein’s quadrupole formula). Detected indirectly from orbiting pulsars and most recently the double-pulsar J0737-3039.

  14. Einstein, Antimatter & the Big Bang Einstein on the Big Bang Theory: “For every billion particles of antimatter there were one billion and one particles of matter. And when the annihilation was complete one billionth remained – and that’s our present universe.” The difference is ascribed to CP violation as seen in elementary particle physics.

  15. Einstein and quantum mechanics • Postulated the existence of the photon (his most revolutionary idea -> Nobel prize) • Described the heat capacity of bodies at low temperatures using quantum theory • Developed the statistics of integer spin systems and predicted the existence of a “Bose-Einstein” condensate (recently discovered at 10 μK) • Predicted stimulated light emission from metastable states (leading to lasers)

  16. Einstein and Unified Field Theory Einstein on Maxwell: “Imagine his feelings when the differential equations he had formulated proved to him that electromagnetic fields spread in the form of polarized waves and with the speed of light!” • Tried to unify electromagnetism and gravity (oblivious of other forces) • Based much on his work on the 5-dimensional extension of space-time by Kaluza & Klein

  17. Higher Dimensional Schemes

  18. Quantum Field theory • To every system (or particle) is associated a quantized field. • Particles are subdivided into source-fields (usually spin ½) and force-fields (usually spin 1). • Fundamental sources are “quarks” and “leptons’. • Force fields include photons, weak bosons, gluons and gravitons.

  19. Source (and some force) fields interact with one another by exchanging force fields.

  20. Particle Generations and the SM 3 (light) generations discovered so far: (ne, e, u, d, u, d, u, d) (nm, m, c, s, c, s, c, s) (nt, t, t, b, t, b, t, b) Interacting via force (gauge) fields: g (graviton), g (photon), W & Z (-bosons), G (gluons in 8 mixed colours) but masses widely different: Mt >350000 Me and Mn <100000 Me. How come?

  21. Magnetic monopoles - where? Maxwell’s equations: • Electric charge ~ spread of electric field • Electric current ~ twist of magnetic field & change of electric field • 0 = spread of magnetic field • 0 = twist of electric field & change of magnetic field i.e. there are no free magneticmonopoles! Searches have never revealed them.

  22. The fundamental scale constants • Planck’s h sets the scale of action • Light-speed c sets the scale of velocity Is there another basic independent scale? Newton’s gravitational constant GN? Einstein’s cosmological constant Λ ? NB: There are many ill-understood scale free constants of nature, e.g. fine structure constant α ~ 1/137, Me/Mp ~ 1/2000, etc.

  23. Bose (commuting) x y = +y x A(x)B(y) = +B(y)A(x) Associate with integer spin fields Symmetric states Obey BE statistics Increase dimension c-numbers Fermi (anticommuting) ξη = - ηξ ψ(x)χ(y) = -χ(y)ψ(x) Associate with ½ integer spin fields Antisymmetric states Obey FD statistics Decrease dimension a-numbers Two sorts of numbers?

  24. Property coordinates? Introduce 5 (complex) a-coordinatesξ0 to ξ4 represent property and attach to the four real c-coordinates x0 to x3 for space-time: X = (xm, ξμ) which can potentially reduce the total effective dimensions of the universe to 0. Property tells us what things (quantum nos.) are involved in an interaction, so any event is characterized by WHERE, WHENand WHAT

  25. Composite properties • As the ξ anticommute there are only a finite number of properties. • Bose fields have even ξ powers, Fermi fields have odd ξ powers. • e.g. e ~ ξ4, n=ξ0 u ~ ξ0ξ1ξ2, d ~ ξ3ξ2ξ4. • Can accommodate 3 particle generations (with 4 extra D and one extra l – nl pair)

  26. Geometrizing gravity • Einstein tied gravity to curvature of space-time • Curvature R ~ matter-energy T • Curvature associated with a space-time Riemann metric squared distance ds2 • ds2 = dxm gmn dxn where gmn is the (10 component tensor) gravitational field • R = R(g) & T = T(energy)

  27. Geometrizing forces • Forces tied to extended metric connecting space to property (e.g. charge due an electron there). • ds2 includes contribution dxm gmµ dξµ where gmµ = λ2 Am ξµ and Am are the gauge fields. • Space-property curvature is the electroweak or chromomagnetic field. • λ is a scaling constant.

  28. rage cry cry rage Geometrizing property • The state of a system is a linear combination of properties. • Metric distance includes term dξµ gµndξn where gµn is the (scalar) Higgs field. • Changes of property depend on order of operation in general. • Property curvature ~ variation in strength of the forces.

  29. The various curvatures • Rspace-space ~ gravity and matter • Rspace-property ~ charges and force • Rproperty-property ~ sources and strengths The total curvature is the sum of all R-terms: it describes gravitational interactions, forces between material sources and includes a cosmological term (its value depends on the constant λ tying property to length in the “metric distance”).

  30. Another theory that bites the dust?

  31. “Any intelligent fool can make things bigger and more complex. It takes … a lot of courage to move in the opposite direction.” “If A is success in life, then A equals X plus Y plus Z. Work is X, Y is play and Z is keeping your mouth shut.” In conclusion: There is a time (t) and a place (x) for every thing (ξ) Some advice from Einstein

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