There are many Big Questions in science, many of which go back to the ancients, even back into prehistory in all probability. One of the best modern set I’ve found recently were sidebars in a book by Emeritus Professor of Physics at the Open University, Russell Stannard. These are my answers, thoughts and commentary to those Big Questions. Many readers might have ‘fun’ trying to come to terms with these in their own way based on their own worldview.
These are the Russell Stannard Questions* on or about cosmology:
Q. How close to the instant of the Big Bang are we likely to be able to probe?
A. We can currently probe or observe no farther back than 380,000 years post Big Bang because the cosmos was too opaque from the point of the Big Bang to roughly that point in time, 380,000 years into the post Big Bang era. However, gravity waves from the Big Bang event could take us to Ground Zero in theory. The problem is in the detection of gravity waves – in theory yes; in terms of actual observation (to date), no. Of course that hasn’t stopped theorists from going back to even less than nanoseconds post Big Bang by running the expanding universe film backwards to the greatest extreme possible, thus postulating and assuming a quantum sized object was at the heart of the Big Bang. Theorists have extrapolated back way beyond what is reasonable or even logical IMHO given so many unknowns. Theory should cease where currently observations cease – 380,000 post Big Bang.
Q. Can we be sure that inflation took place?
A. No, because we weren’t there! Seriously, we have no direct observational evidence of inflation, only indirect evidence that a theory or theories of inflation can explain some observations (or lack of observations, like where are the monopoles). This reminds me of those epicycles once postulated to explain observations related to the motions of the planets in the night skies. Those epicycles eventually bit the dust; inflation might too.
Q. If so, how are we to choose which type of inflation it was?
A. Pick a card, any card! Whatever theory of inflation best matches the observations and best conforms to what is known about the laws, relationships and principles of physics goes to the head of the class.
Q. Was there a singularity at the instant of the Big Bang?
A. No, there was no singularity associated with the Big Bang event. A singularity in common usage by physicists implies a region of space that has zero volume and infinite density. Sometimes I think these eggheads need to observe the real world where volumes and densities are finite. In any event, the density at the point in existing space where the Big Bang happened had to be less than that of a Black Hole, otherwise there would be no ‘bang’. That in turn implies the Big Bang was a macro event, something that happened way outside the realm of quantum physics.
Q. Does it make sense to enquire into the cause of the Big Bang?
A. Yes, absolutely! There had to have been a cause, physical or software, and it is quite legit to ask what that cause was and try to answer the question. Of course I never said that would be easy.
Q. Are there universes other than our own?
A. If you reject the supernatural and the software and coincidence, then you are left with the multiverse scenario to explain why we are here. We are in the one successful universe that produced that word-for-word typing of “Hamlet” by those millions of monkeys.
Q. What is the nature of dark matter?
A. Dark matter doesn’t actually exist. It is inferred only because the fallible Supreme Programmer made an ‘oops’ when programming the minimum required for the cosmic background wallpaper in our Simulated (Virtual Reality) Universe.
Q. How are we to account for the observed value of the dark energy?
A. There is only ‘dark energy’ if the Universe is really accelerating when it comes to the expansion rate of the Universe. Cosmologists had to invent some sort of explanation for this anomalous observation, so why not call it ‘dark energy’ even if they haven’t the foggiest idea what it actually is. Now you know, and I know, that the Universe cannot be expanding at an ever accelerating rate due to that little factor we all acknowledge called gravity. Gravity exists; so-called ‘dark energy’ is theoretical, ad hoc, an epicycle and iffy at best. An accelerating Universe is like your car going uphill at an ever faster and faster rate without you putting the pedal to the metal. I’m reasonably certain that what has been interpreted as the expansion rate of the Universe accelerating has some other explanation. Perhaps not all type 1A supernovae are really peas-in-a-pod and thus are not the standard candles we think they are. Perhaps the velocity of light isn’t a constant after all and changes over cosmic time. That would throw one heck of a monkey wrench into the scenario. So, ‘dark energy’ doesn’t have a value since the Universe isn’t really accelerating. If, however, the [Simulated] Universe really is accelerating, then that’s obvious evidence for our Supreme Programmer screwing up the cosmic background wallpaper software. It’s just an ‘oops’, an oversight in overlooking the consequences of programming this variable at this value instead of some other variable at some other variable.
Q. Does the density of the dark energy remain constant with time?
A. There is no ‘dark energy’ IMHO so the question has no relevance. However, if the value or density of the alleged ‘dark energy’ is allowed to vary over cosmic time, then one could just about explain any observation relating to any value of the expansion rate of the Universe.
Q. Is there a connection between today’s repulsion of the galaxy clusters and the period of inflation?
A. If there was such an animal as inflation that happened quick-smart and cheek-by-jowl with the Big Bang event, well some force or other had to be responsible for blowing up that cosmic balloon. Fast forward to today and we see galactic clusters moving away from each other as if each had a bad case of B.O. Again, there must be some force acting on these clusters repelling them. I though conventional wisdom put that down to the so-called ‘dark energy’ but if there really is a ‘dark energy’ and if there really was a repulsive force that drove what we allege was cosmic inflation, it might be odd if the two repulsive forces in question didn’t share some sort of physics ancestry assuming they aren’t exact clones.
Q. Is the universe infinite in size, and if so, what exactly does that mean?
A. The universe is infinite in size solely on the philosophical grounds that one can always ask the question ‘what is beyond’ this barrier or at right angles to where I am. There always is a beyond, even if you have to postulate a higher dimension to get there, as it inhabitants of 2-D Flatland can escape by going into the third (higher) dimension that’s so familiar to us. In the Simulated (Virtual Reality) Universe scenario, well we’ve probably all seen computer/video games that have a wraparound feature. Something goes off the screen to the right or at the top and reappears at the left or at the bottom. That’s an infinite loop. To the inhabitants, it’s an infinite size where you can go round and round the mulberry bush for all eternity.
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*The following questions were taken verbatim from those poised by Russell Stannard in his 2010 book The End of Discovery [are we approaching the boundaries of the knowable?]; Oxford University Press, Oxford. I consider these typical of the sorts of modern Big Questions that are part and parcel of the philosophy of modern science, especially physical science.
