What Is Reality?

I am veering off into the world of science, will have a couple of posts on this topic in the next few weeks.  Also hoping to spend a little time on artificial intelligence.  You read a little in the regular media about these areas, but it is very superficial so I am trying to get a firmer grasp on what they really mean and how they actually work. (I know this is a very simplified explanation which misses much complexity, so please bear with me.  I am just trying to help people be aware of a fascinating part of life and to send you in a direction to learn more.)

Over a hundred years ago, physics, and particularly the branch of physics concerned with explaining the laws governing and nature of everything endured a true upheaval as the notion of quantum mechanics and other branches of quantum theory were developed.  I am writing this post to share an article which I think does a pretty good job of breaking an incredibly complex and counter-intuitive theory down to simpler terms.  It is very, very hard for us to wrap our heads around the implications of this theory.  But experimental evidence appears to show that it is an accurate description of the universe at an ultra-small level.

One thing these explorations always remind me of is the incredible intelligence humans have and the extensive body of knowledge we have built up in a short time.  Since the start of the more scientific approach to understanding the world millenia ago, humans thought matter was made up ultimately of some very small particles which aggregated in various ways to form larger masses that we experience in daily life.  Molecules, atoms, electrons, neutrons, protons, quarks, and an ever-increasing array of particles have been discovered.  These particles were thought to interact with each other via a set of forces and and to produce various energies. But certain phenomenon did not seem to be fully explained by particle theories, including light and gravity and magnetism and electricity.  And so more advanced electromagnetic theories came about and relativity and quantum mechanics, which indicated that the universe is a complex interaction and mix of particles and waves.

The primary revelation which drove this new theory was that light behaved like both a particle (the photon) and a wave.  Other particles were found to have a similar dual nature.  Worse yet was that there appeared to some indeterminate aspect to reality at this extremely small scale.  You could not know all characteristics of a particle when you measured it, and the very act of measurement might change or fix a characteristic.  And energy seemed to come in certain discrete packets, which were referred to as quantum or quanta in the plural.  The wave aspect of particles had characteristics that were best described by probability functions, which just seems very weird.  Is this particle here at this point in time?  Well, there is a 67% chance of that seems like an odd answer, but experiments seem to suggest it is so.

But perhaps the most bizarre aspect of quantum theories is that a system can be in more than one state simultaneously and only “collapses” into a particular state when a measurement is attempted.  Most famously is Schroedinger’s cat in a box, it is both dead and alive, and you only know when you open the box.  And then there is entanglement, completely mysterious to me and referred to by Einstein as “spooky action at a distance”.  Particles can become correlated or entangled and even when moved a great distance apart, an action on one will instantaneously affect the other.  China has demonstrated this phenomenon from as far as the earth to an orbiting satellite.  Trying to wrap our human brains around what our intelligence seems to be telling us about the fundamental nature of the universe is baffling.  Fortunately, it doesn’t affect our daily lives much, yet.  (Seigel Article)

And if you want to read a good history of the development of quantum theories and some of the key debates, I would recommend Quantum Drama by Baggott and Heilborn, which describes the initial work leading up to the development, with Einstein and Niels Bohr playing key early roles, often on opposite sides.  The book goes on to give the history of further refinements, highlighting the particular scientists involved.  I hope you will take a look and I hope you find this whole topic as captivating as I do.