What was there before the Big Bang? – a new theory from Roger Penrose

Sir Roger Penrose, from the 7th Edoardo Amaldi Conference on Gravitational Waves

Sir Roger Penrose, from the 7th Edoardo Amaldi Conference on Gravitational Waves

On Friday evening, 13 July 2007, the British physicist, Sir Roger Penrose, gave a mind-expanding and mind-boggling talk at the Darling Harbour Convention Centre. The public lecture was part of the 7th Edoardo Amaldi Conference on Gravitational Waves and it involved the presentation of the Dirac Medal of the University of NSW to Sir Roger.

Until now the official answer to the question of what was there before the Big Bang was that we do not know and we will never know as time only began at the Big Bang. About two years ago Sir Roger thinks he may have found an answer that he presented to a fascinated audience in the Bayside Auditorium. Your humble blogger attended the lecture and attempts a brief summary below:

He started by stressing the importance of the second law of thermodynamics that states that disorder or entropy must always increase. For example, at the Big Bang the Universe began in a low entropy state as illustrated by studies of background radiation left over from shortly after that time, the cosmic microwave background. Since then entropy has always increased.

Sir Roger also mentioned the Weyl curvature. This is a property of space that leads to the bending of light rays from distant galaxies by ones in the foreground – usually referred to as gravitational lensing. His Weyl curvature hypothesis proposes that the Weyl curvature was zero at the big bang.

According to the new theory as the Universe expands all the particles of matter are collected into black holes. These destroy the information content of matter and hence reduce entropy. The black holes radiate Hawkins radiation and after a very very very long time disappear – for instance for a three million solar mass black hole like the one at the centre of the Milky Way the time is 10 to the power of 84 years. When all matter has disappeared and entropy has been reduced a new Big Bang can take place. Sir Roger calls this sequence of one universe being formed after the death of the previous one conformal cyclic cosmology.

There are observational consequences of the theory as the previous Universe may have left behind a faint subtle pattern in the cosmic microwave background. It is now up to observational cosmologists to search for that tell-tale pattern.

4 responses to “What was there before the Big Bang? – a new theory from Roger Penrose

  • I am writing to you about an idea that crossed my mind .I present it to you for what it is worth.
    It strikes me that a universe with no beginning(an universe that has always been there) and a universe with a beginning(with a point of origin for Space and Time )are equivalent from th pont of view of Time.In both cases,we cannot apply the question “What there was before this universe came into being?”:in the case of the Universe that has always been there,the question is impossible.And In the case of the universe with a beginning, the question is impossible too,because “before”has no meaning if there is no time,,as you have said yourself.So ,to resume,”before”has no meaning in both case.Conclusion:There is no difference ,from the point of view of time ,to say :”The universe has always been there!”or to say:”It started with Time somewhere in the past” because “Always” signifies that “Before” cannot apply which is the case in both the universe that started with a Bigbang and the universe eternally there. And we can also said ,that at this level of reality ,the Finite and the Infinite are two attributes of Time coexisting together.

  • OK I seem to have understood it differently. It’s the vanishing of mass i.e. decay of all mass to energy (and therefore time stopping/not existing?) that brings the Weyl curvature back to zero. This has the consequences of end of time and beginning of time been indistinguishable. Therefore the beginning is the end and the end is the beginning?
    Very poetic.

    PS. But here is the big but, electrons have to decay!

  • Entropy of a closed system can only increase over time according to the 2nd law of thermodynamics. Non closed systems such as living organisms can decrease their entropy ie become more organised or structured by taking in and using an outside source of energy.

    Now Penrose says that as matter disapears into black holes then entropy of the universe decreases. Assuming that the universe is a closed system, where is the external source of energy coming from. Is it that the energy is already available within the closed system to drive the reduction of entropy? Is this available energy source the energy of matter as it is gobbled up by the black holes or is it the vacuum energy.

    Is the entropy/energy relationship a reversible transformation?


  • Yeah I went along too. Fascinating stuff.

    Great to see that black holes have got an important function in the evolution of the universe.

    Too weird just to be there doing nothing in particular.

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