Review of “Richard Easther on Fine Tuning”
Fine tuning the universe: the review
It is frequently suggested that the fundamental laws of physics must be “tuned” to ensure that the universe can permit the existence of life. So we got in Prof. Richard Easther from the department of Physics to discuss some of these purported tunings in cosmology and fundamental physics, ask how they might be explained, and get his take on their implications.
Richard started off with what do we really mean by fine-tuned? There are currently four forces in the standard model of Physics (electromagnetism, the strong and weak nuclear force and gravity) but could a universe exist with less or more forces? Are the values for these for forces fixed or could they vary? It seems that although we do not know for certain we are getting close! So the question is why do we see a universe like this one? One that is apparently tuned for life.
From one perspective, the universe is not as tuned as we would be lead to believe. Out of the very large volume that the universe contains, only the smallest fraction of it can support life as we know it. If you were an entity creating a universe for life you would think you could tune it to be a little more life friendly. Also the term, “life as we know it”, has an important distinction. If the universe did have a different set of rules which would not allow “life as we know it” to form, there is no guarantee that life would not pop up in another form, a form that could not survive in a universe with our current set of rules. So the question becomes, why the universe has the observed set of rules rather than another.
Well it appears that in quantum physics the multiverse proposed by our favourite sci fi flicks may not be so far off from the truth. String and M theory are models that are predictive in their power to explain the Phenomena that we see in the universe round us.It turns out that many cosmological theories are built on a set of equations that end up predicting multi universes as a natural and necessary by-product of their other predictions. Each of these other universes has its own potentially unique set of rules, some maybe the same, some just slightly different rules to our universe. To be clear, a new one is not created every time you make a choice, rather normal quantum fluctuations start the inflation of a new universe at another location. If these happened close to our own universe just after our own big bang we may even get to see their impacts on the cosmic microwave background but we will have to stay tuned for that.
Just as we may have asked the question a 1000 years ago, “Why is our world so fine tuned for life?” and the answer being “it is not, it is just one of many possible planets” we are now getting to understand that the answer is the same for our universe. It is not.