The Universe is a pint of beer
Whilst not as refreshing, nor capable of being contained inside a standard pint glass, the universe is surprisingly like a pint of beer.
How, you may ask. Well, it’s all to do with the way that nucleosynthesis, gravity and quantum weirdness happen.
In the beginning (where ‘the beginning’ is between 3 and 20 minutes after the Big Bang), matter condensed out of energy - protons (hydrogen ions) and neutrons begin to combine into atomic nuclei in the process of nuclear fusion. Free neutrons combine with protons to form deuterium. Deuterium rapidly fuses into helium-4. Nucleosynthesis only lasts for about seventeen minutes, since the temperature and density of the universe has fallen to the point where nuclear fusion cannot continue. By this time, all neutrons have been incorporated into helium nuclei. This leaves about three times more hydrogen than helium-4 (by mass) and only trace quantities of other nuclei.
Eventually, localised clusters of these atoms coalesce into clouds, these clouds collapse slowly under their own gravity and form the first stars. These stars, through a process of nuclear fusion in their cores, turn hydrogen into helium, then turn that helium into carbon and, if the star is large enough, eventually into iron. Massive stars supernova at the end of their lives, pumping enough energy into their constituent elements to force heavier than iron fusion - this is where all the gold, platinum and other heavier than iron elements are formed and then thrown out into the universe, to join with other free floating elements and form the next generation of stars and planets.
So far so good. But where’s the beer?
Well, now we have almost every naturally occurring element floating around in space, oftentimes close to a star. Some of these clouds are very dense, and flooded with radiation from the nearby stars. Under these conditions, molecules can form and join together into more complex structures. We have discovered that in some nebulae, water, ammonia, carbon, carbon dioxide, formaldehyde, acetylene, ethyl alcohol, methyl alcohol, methyl cyanide, vinyl cyanide, formic acid, silicates and other molecules are present. Ethyl alcohol, also called ethanol, is the type of alcohol that is present in beer and other alcoholic drinks. One such nebula, called Sagittarius B2, is 390 ly from the centre of the Milky Way. This cloud is one of the largest in the galaxy, spanning a region about 150 light years across and contains large quantities of ethanol (approximately 10,000,000,000,000,000,000,000,000,000 litres). This is one phenomenally alcoholic nebula.
So, we have our alcoholic content, water content, other flavourings and carbon dioxide for fizz, now we need a good head on our beer. As it turns out, the universe may be very good at generating its own foam as well.
In 1995, an American physicist called John Wheeler took General Relativity and Quantum Mechanics and attempted to merge them together. Gravity, as Einstein proved, was a bending of the fabric of spacetime. Place a point far away from the Earth, and it still will be inside of the Earth’s gravitational field, but the pull of gravity will be weak. Place it close to the Earth, and the pull is stronger. Space isn’t gravity-free, but a vast array of different gravitational fields through which particles move. Pretty much everywhere that anything is placed, there is a gravitational field that it moves through.
Quantum mechanics doesn’t work quite the same way. It is looked at as more point particles and waves, without fields. Quantum field theory attempts to look at space as another field that point particles move through. This is significant because it allows space to also be a field that point particles spring from.
We know that particles can spontaneously appear out of the ‘nothing’ that is empty space - apparently in violation of the principle of conservation of energy. These particles are amazingly short lived - appearing and disappearing in fractions of seconds, only appearing to ‘borrow’ energy and mass from the universe, and almost instantly giving it back, thereby maintaining the conservation of energy principle. If we had instruments capable of seeing short enough time spans and at subatomic scales, we would see these particles appearing and vanishing, seemingly at random, in every square centimetre of ‘empty’ space constantly.
Relativity showed that spacetime is a physical thing; that it can get bent, stretched and distorted by mass and energy. These huge fluctuations in mass and energy over tiny, tiny distances distort the fabric of spacetime in subtle ways. Even tiny fluctuations in mass and energy have an effect, but a much, much smaller one. The biggest fluctuations cause effects that can be seen across galaxies; gravitational lensing, the motions of galactic clusters and other things on scales that we can observe.
Wheeler imagined that this indeterminacy for spacetime required that at the Planck Scale of 10-33 centimetres and 10-43 seconds, spacetime has a foaminess to it with sudden changes in its geometry into a wealth of complex shapes and textures. You would have quantum black holes appear at 10-33 centimetres, then evaporate in 10-43 seconds.
If we were capable of zooming in to subatomic scales, to a point where these particles were observable, we would see that they too have an effect on spacetime, but at the subatomic level, on scales so infinitesimal, that they are hard to comprehend. We would see that spacetime, at these scales, is not a smooth, flat ‘surface’, but a constantly churning, roiling, boiling sea of fluctuations. Instead of a smooth surface, we have quantum foam.
So, we have our alcoholic content, our water, our flavourings, our fizz and now our foamy head for our beer.
Read back a few paragraphs and go through that list of things that we have found in nebulae again and we find the last thing we need - silicates. In order to enjoy our universal beer, we are going to need something to drink it out of. It turns out that the universe pretty much provides all the ingredients we need to make a good, sturdy glass out of as well. Now all we need is the technology to get out there and collect it all.