A grounding in physics means you can never be bored.
Most of the weirdness of quantum mechanics though, is because geometry with more than 4 dimensions is outside our normal experience plus nobody explains that the extra dimensions were rolled up into spacetime in the first femto seconds of the big bang. They are there, but we don’t have to deal with them in our everyday lives, unless we are theoretical physicists
On gravity, it is probably more accurate to state that there is no agreed theory that unites Newtonian physics (things larger than an atom) with quantum mechanics (things smaller than an atom) and gravity is the key here as it is the force that must be accommodated in a theory of everything.
In the first three hundred thousand years after the big bang there was only one fundamental force, which broke apart into the strong and weak nuclear forces, the electromagnetic force and gravity, Einstein spent most of his life trying to understand how to put them back together again to formulate an ultimate theory of everything or unified field theory and failed, as usual he was too far ahead of the technology of his day.
Why is this theory of everything so important ? Because ultimately the fate of the human race may depend upon it.
In the 1960’s the Russian physicist Nikolai Kardeshev formulated a table for classifying the type of civilisations we would most likely find evidence of, using radio astronomy. This method of classification is based on energy output.
A type 1 civilisation would be capable of using the total amount of solar energy striking their planet, approx 10X16 watts, this amount of energy would allow such technologies as controlling the weather for maximum food production along with maybe asteroid mining to satisfy other resource needs.
They are masters of their planet.
A type 2 civilisation can harness the entire solar output of a their star, about 10X26 watts, Freeman Dyson imagined that such a civilisation could recycle some of the planets in their system to build a Dyson Sphere around their star.
Such a civilisation would be the masters of their solar system.
A type 3 civilisation would be capable of harnessing the solar output of a significant portion of their galaxy, approx 10X36 watts.
Such a civilisation would be masters of whatever they choose.
The three civilisation types are separated by power usage of 10 billion watts.
Carl Sagan later refined the classification in order give us a place in the order of things, he subdivided each type by 10, we are a type 0.7, depending for the most part on burning old plant residue (oil and gas), a thousand times feebler than a type 1 civilisation but getting there.
We are beginning to see how things turn out as we climb the energy expenditure league, the internet is the first incarnation of a planetary communication system. As we increasingly talk to each other as people rather than nationalities, perhaps the threat of self destruction diminishes, for that is certainly the major threat to our existence as a species.
But back to the start of my post, almost all of the technology we see around us has been assembled from about a century and a half of halting understanding of electromagnetism along with a sprinkling of understanding of the strong and weak nuclear forces contributed over approx the last 70 years, now if we can only harness gravity into our equations, we may begin to harbour thoughts of being a type 1 civilisation, safe from self destruction if not from a nearby supernova.
String theory/M theory is our best hope towards understanding how gravity can make us safe from ourselves.
Pat Gill 3 August 2010