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Showing posts with label Large Hadron Collider. Show all posts
Showing posts with label Large Hadron Collider. Show all posts

Saturday, October 10, 2009

The Big Bang, the LHC and the Evolution of the Creation of the Universe by Brian Cox

In "There's probably no God, the Atheists Guide to Christmas" edited by Ariane Sherine, Brian Cox has a chapter on the Big Bang titled "The Large Hadron Collider: A scientific creation story". I've summarised it and added further details from the hour long video by Brian Cox at CERN.

The LHC recreates the conditions of the universe less than a billionth of a second after the big bang. The job of the LHC is too study the universe during the time when the Higgs particles are thought to have been generated. The history of the universe is thus:

  • 13.7 billion years ago universe begins (t=0)
    • gravity separates from the other forces of nature (t+10-43 seconds)
    • exponential expansion of universe (t+10-36 s)
      • from size of electron to size of melon (t+10-32 s)
      • with formation of sub-atomic particles
        • and Higgs field (t+10-12 s)
          • gives mass to sub-atomic particles
            • Higgs acts like cosmic treacle
          • if Higgs particles aka Higgs Boson, aka The God Particle (Leon Lederman) exist (after 40 years we don't know) then Higgs Boson must be created in LHC (Standard Model)
          • Higgs particles decays too quickly to be seen even in LHC 
            • but Muon will be seen from decay of Higgs particle 
          • Higgs Boson is tens or hundreds of times heavier than the protons that were smashed together (mini big bang) to create it (E=mc2). Energy=mass
            • because Higgs particles are light enough to show up in LHC
          • if Higgs particles are NOT found in LHC 
              • some other mechanism (Minimally Supersymetric Standard Model?) will show up in LHC which creates mass
              • and explains Dark Matter
After t+10-12 s time we already know what happened to the universe because smaller cousins to LHC (eg Fermilab Tevatron?) have been working for decades:-
  • 4 forces of nature (strong nuclear, electromagnetic, weak, gravity) formed (t+10-6 s)
    • strong nuclear force
      • binds quarks together in nucleus of atom
    • electromagnetism
      • holds electrons in place around nucleus
    • weak force
      • allows sun to shine, explains radioactive decay
    • gravity
      • is missing from Standard model
        • creates infinities when gravity is added 
          • if treat particles as tiny points, when they come infinitely close together, gravity becomes infinitely strong 
          • by treating particles as strings (not tiny points) we have a way for gravity to work
      • but gravity is included in Einstein's General Relativity
        • a Theory of Everything would combine Standard model with General Relativity
        • String Theory combines all particles and forces (and makes a decent cup of coffee!)
  • quarks and leptons interact
  • quarks stick together to give protons & neutrons, neutrinos roam universe (t+1 s)
  • protons & neutrons form elements (t+3 minutes)
  • Hydrogen 75% : Helium 25% ratio fixed (t+30 m)
  • Light as Photons set free from dense universe: cosmic microwave background (t+ 380,000 years)
  • gravity collapses H & He to form stars
  • 4 forces of nature interact: x3 He fuse to give Carbon
    • more fusions give oxygen and other light elements
  • stars run out of fuel, explode 
    • scattering C & Oxygen & other light elements
    • creating Gold, Silver & other heavy elements
  • gravity forms stars & dense rocky planets orbit
  • on at least one planet, occurs self replication & life & us!
Additional material added above from the 5 YouTube videos:-

Creative Commons License
This work by crabsallover is licensed under a Creative Commons Attribution-Non-Commercial-Share Alike 2.0 UK: England & Wales License.

Sunday, May 04, 2008

Talks Brian Cox: What really goes on at the Large Hadron Collider

A neat explanation of what the CERN LHC hopes to achieve. The Higgs Boson (gives mass to particles), Supersymetry are discussed.

"Rock star physicist" Brian Cox talks about his work on the Large Hadron Collider at CERN. Discussing the biggest of big science in an engaging, accessible way, Cox brings us along on a tour of the massive complex and describes his part in it -- and the vital role it's going to play in understanding our universe.

Friday, January 25, 2008

Large Hadron Collider - Southampton Cafe Scientifique















I attended a talk by Prof. Nick Evans at Southampton Cafe Scientifique on 24th January. He talked entertainly and in simple terms about the Large Hadron Collider (LHC) (wiki) coming into operation in May 2008 at CERN Switzerland. The talk was well attended with 80+ persons.

Prof. Nick Evans, School of Physics and Astronomy, University of Southampton

Cafe Scientifique say 'In just a few months particle physicists will be switching on a multi-billion pound atom smasher in Geneva called the Large Hadron Collider. This machine will probe the most basic building blocks of nature and shed light on our understanding of the masses of particles. Excitingly, the machine must uncover the explanation to a missing piece in our understanding of the weak nuclear force. Speculation is rife as to what will be found from the mysterious Higgs particle to "supersymmetry" or extra dimensions of Space-Time.'


The main points that he presented were:-
  • detecting the Higgs Boson is the main aim of LHC
  • LHC costs $2.6 billion over 10 years - this is comparitively a small amount of money
  • LHC will probe the nature of matter by firing hadrons (eg protons) into each other at speeds approaching speed of light with 14TeV 'smashability'
  • we humans see a 4 Dimensional world - if hadrons at LHC collide and some of the energy of collision is not accounted for - then maybe the energy has gone to another dimension (String Theory predicts 11 dimensions)
    • LHC is unlikely to give experimental support to String Theory (cf. Lisa Randall)
  • all matter is composed of 3 fundamental particles: electrons, up quarks, down quarks
  • a proton contains 2 up quarks and one down quark
  • a neutron contains 2 down quarks and one up quark
  • electrons v electron neutrino
  • he successfully resisted the temptation to delve into detail!
  • he only mentioned his book twice, en passant!
  • his (tongue in cheek) goal is to get a Nobel Prize!
  • we could be in for some surprises at LHC!!
  • whatever happens LHC will get some results
    • LHC is expected to be able to confirm or deny the existence of the Higgs boson in most circumstances.
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