Monday, 27 February 2017
Particle Physicist Professor Jeff Forshaw of the University of Manchester provided a stimulating lecture at Bolton School on Monday evening. Based on his popular book co-authored with Brian Cox, his lecture ‘Universal’ traversed a journey of scientific exploration which helped a fascinated audience understand some of the most fundamental questions about our Earth, Sun, Solar System and the star-filled galaxies beyond.
Opening the evening by declaring that evidence for the “Big Bang” is pretty compelling, Professor Forshaw explained how 13.7 billion years ago the Universe was exceptionally hot and dense before, from a tiny point, the Big Bang took place detonating an expansion into what we know today, namely over 100 billion observable galaxies. One minute after the big bang, temperatures cooled to one billion degrees and for every proton there was a billion photons. The rapidly expanding gas, predominantly hydrogen, made our stars as space itself was and still is swelling out. As conditions changed, helium and deuterium formed and a tiny amount of lithium. 380,000 years after the Big Bang, there had been a further cooling and atoms began to form. Using the analogy of bread baking in an oven, he likened raisins in the bread moving away from each other to stars moving away from each other and said that each day the observable universe grows larger.
Professor Forshaw revealed how scientists have discovered that there are microwaves coming from every direction in space and that relatively uniform cosmic microwave background radiation is believed to be the remains of energy created just after the Big Bang; he exalted the Planck Satellite as an exquisite instrument for measuring the deviations of microwave heat. Summing up the evidence for the Big Bang theory, he said it comprises three key elements: the Big Bang nucleo-synthesis, the existence of microwaves and an expanding universe.
Addressing the issue of what happened before the Big Bang and how things can be created out of a vacuum, he explained how Quantum Physics posits that there are always particles in a vacuum, appearing and disappearing fleetingly and that there is a theoretical calculation that predicts what will appear. What we think of as empty, is not, he told the audience and reminded them about Superstring Theory that suggests our universe exists in ten dimensions and is far richer than we can appreciate with our senses. Going back to the time after the Big Bang, he spoke of how a slowing down in the inflaton field allowed the energy in the field to produce the constituents of our own observable universe which allowed particles to be formed. He cited the equation of E=mc which illustrates how energy can be converted into mass and used the formation of dew as an example of something that seems to materialise out of nothing.
Professor Forshaw told how the Universe is made up of 70% dark energy, which we do not understand at all; 25% dark matter, which we don’t know what it is but we do know how it effects things and how much there is; and just 5% matter.
The concept of a multiverse was discussed and how our own observable universe could just be a tiny part of a larger bubble and how string theory supposes that there is an infinite number of possible universities with potentially different laws of physics in each. This, he said, opens up significant theological and philosophical questions and introduces the idea of God as a simulator not a creator!
Addressing questions, he dismissed the concern that something catastrophic could have happened when the Hadron Collider experiments took place, saying it had been equivalent to someone turning a light switch on in a room and expecting the universe to blow up. Asked where the inflaton field came from, he said “who knows?” and went on to discuss the assumption that inflation, which propels everything outwards from the Big Bang, has been going on for ever and how some people are happy with this idea of an eternal universe.
You can relive Professor Forshaw’s lecture through these videos:
Universal: Part 1
Universal: Part 2
Universal: Part 3
Universal: Questions and Answers
Copies of hiss books Universal, The Quantum Universe and Why Does E=Mc2? (all co-written with Professor Brian Cox) were available for purchase and signing after the event.
The evening lecture was part of a series of Arts and Science presentations which are taking place in the Girls' Division of Bolton School and are open to the public. This event was attended by Ogden Trust members and aspiring physicists from local schools including Sharples, Canon Slade and Montgomery High School from Blackpool. The next lecture will be from Dr Heather Williams on Monday 27 March at 7pm.
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