Is a public understanding of abstract physics concepts feasible?

Is a public understanding of abstract physics concepts feasible? Johannes P. Wessels InstitutfürKernphysikWestfälischeWilhelms-UniversitätMünster and CERN, Geneva • Aspects of the nature of matter investigated at the Large Hadron Collider • What is the nature of matter? • How do we study it? • What are our (physicists’) physics concepts? • If they appear to be abstract, how do we try to motivate, communicatethese concepts?Analogies – do you find them useful?

How abstract is abstract? Opinions Quantum Mechanics cannot be understood.Richard P. Feynman The most incomprehensible about nature isthat she is so comprehensible. Albert Einstein physics is looking for guiding principles of nature

Size of the Universe 3*1025m each of the 9325 dots represents an entire galaxy

…at 1021m… …our galaxy with its roughly 1011 “Suns”

…at 1020m…

…at 1014m… …finally our solar system

…at 1011m… …roughly six weeks of the earth’s path

…at 109m… …the moon’s orbit

…at 107m… …not so unfamiliar

…at 106m… …a 1000 km of cultural heritage (and vacation)

…at 105m… …space shuttle calling Geneva…

…at 104m… …approaching GVA…

…at 103m… …CERN just before landing

…at 102m… …part of where CERN’s 10000 people work

…at 100m… …in a beautiful setting

…at 10-1m… …which gets more and more interesting

…at 10-2m… …the closer…

…at 10-3m… …you look… jpw - Single Cell 2008 - 24.11.2008

…at 10-5m… … ever more interesting …

…at 10-7m… …till you see things that can’t be seen with ‘normal’ light…

…at 10-8m… …special light sources can even illuminate single molecules… how abstract / real is this?

…at 10-10m… …reaching atoms, that are essentially “empty” … how familiar / correct is this?

…at 10-14m… …almost the entire mass of the atom is concentrated in the nucleus, which consists of neutrons and protons… How useful is it to know that, if the earth were of that density it would fit into a cube of 300x300x300 m3?

…at 10-15m… …neutrons and protons in turn consist of quarks and gluons.These quarks may well be point-like particles. They can NEVER be seen in solitude. THE matter investigatedat the LHC.

Physics - in Search for Similarities The Complex Synapses The Biggest The Smallest Meters Stars K.H. Meier

Composition of the Universe Dynamics of the evolution governed by interations -> forces 23% 72%

Concept of Interaction - Force Newton: actio = reactioforce fields work at a distance - potential standard model: forces are mediated by the exchange of particles Interaction entailsscattering Time Feynman-Graph Position

4 Fundamental Interactions falling apples,planetary orbits strength: 10-39 range: infinite mediator: graviton? television, magnets,chemical binding strength: 1/137 range: infinite mediator: photon nuclear stability, quark confinement strength: 1 range: 10-15 m mediator: gluon -decay, neutron stability, neutrinos strength: 10-5 range: 10-18 m mediator: W,Z-Boson

4 Fundamental Interactions falling apples,planetary orbits strength: 10-39 range: infinite mediator: graviton? television, magnets,chemical binding strength: 1/137 range: infinite mediator: photon nuclear stability, quark confinement strength: 1 range: 10-15 m mediator: gluons -decay, neutron stability, neutrinos strength: 10-5 range: 10-18 m mediator: W,Z-Boson

4 Fundamental Interactions falling apples,planetary orbits strength: 10-39 range: infinite mediator: graviton? things we can relate to television, magnets,chemical binding strength: 1/137 range: infinite mediator: photon nuclear stability, quark confinement strength: 1 range: 10-15 m mediator: gluons -decay, neutron stability, neutrinos strength: 10-5 range: 10-18 m mediator: W,Z-Bosons things we cannot relate to

All Partilces of the Standard Model really all of them? important symmetry: each particles has a corresponding anti-particle. creation always in pairs

Example: The Electron Time Position which interaction a particle is subject todepends on its charge (charges) In case of the electron: participates in electromagnetic, weakand gravitational interaction electrical charge couples to the poton strength depends on the coupling constant a In case of the weakinteraction charge -> weak charge and weak coupling constant In case of the gravitational interaction charge -> mass and gravitational coupling constant

Example: Strong Interaction Quarks are subject to the strong interaction. The corresponding ‘charge’ is the color charge(r,g,b). The mediators (exchange particles) are the gluons. Position Time Gluons carry color charge, therefore, they interact amongst themselves strongly.

Confinement d all strongly bound objects are color neutral. they are either baryons consisting of 3 quarks or mesons consisting of a quark and an anti-quark. d u u Proton u Confinement:There are no free quarks in nature. How do we know about them and their properties? Pion +

The “Right” Light to Look Inside of Things Vision works byscattering of‘visible’ light “Vision” of even smaller structures viascattering of particles  = 400-700 nm  = h/p

Accelerators Acceleration of a charge in an electric field: E = q•U For the LHC you would need 2 times 7000 trillion batteries

…the “Light” from Large Accelerators LHC ALICE SPS jpw - Single Cell 2008 - 24.11.2008

Either shoot on stationary target or collide beams Recall Einstein’s famous equation E=mc2 for particle production

…Seeing? - we have no sense for particle radiation.So, we need suitable detectors.

Bubble ChambersOne of the first detectors to ‘view’ complex particle production events. jpw - Single Cell 2008 - 24.11.2008

jpw - Single Cell 2008 - 24.11.2008

LEP SPS L3 fully electronic “eyes” - here L3 jpw - Single Cell 2008 - 24.11.2008

…so we can “see”! what constitutes seeing or evidence?

A physicists view on SEEING particles

The general public’s view on particles

All Particles of the Standard Model have been ‘seen’that way. only the lightest are stable! their masses differ hugely

Is a public understanding of abstract physics concepts feasible?