Cosmologic philosophy: fine tuning constants (Introduction)

by David Turell , Sunday, May 08, 2016, 14:55 (3121 days ago) @ David Turell

This is a long essay on the constants that support the fine tuning of the universe. It starts with a discussion of the speed of light, and the title suggests that is all there is, but it ranges on to explain many aspects of the constants. It explains the virtual vacuum space we exist in. Worth reading for education: - https://aeon.co/essays/why-is-the-speed-of-light-the-speed-of-light?utm_source=Aeon+New... - "What's a quantum fluctuation? Heisenberg's Uncertainty Principle states that there is always some indefiniteness associated with physical measurements. According to classical physics, we can know exactly the position and momentum of, for example, a billiard ball at rest. But this is precisely what the Uncertainty Principle denies. According to Heisenberg, we can't accurately know both at the same time. It's as if the ball quivered or jittered slightly relative to the fixed values we think it has. These fluctuations are too small to make much difference at the human scale; but in a quantum vacuum, they produce tiny bursts of energy or (equivalently) matter, in the form of elementary particles that rapidly pop in and out of existence. - *** - "It will take a full analysis and some experiments to prove that c can really be derived from the quantum vacuum. Nevertheless, Leuchs tells me that he continues to be fascinated by the connection between classical electromagnetism and quantum fluctuations, and is working on a rigorous analysis under full quantum field theory. At the same time, Urban and colleagues suggest new experiments to test the connection. So it is reasonable to hope that c will at last be grounded in a more fundamental theory. And then - mystery solved? - *** - "The speed of light is, of course, just one of several ‘fundamental' or ‘universal' physical constants. These are believed to apply to the entire universe and to remain fixed over time. The gravitational constant G, for example, defines the strength of gravity throughout the Universe. At small scales, Planck's constant h sets the size of quantum effects and the tiny charge on the electron e is the basic unit of electricity. - "The numerical values of these and other constants are known to excruciating precision. For instance, h is measured as 6.626070040 × 10?34 joule-second (to within 10-6 per cent!). But all these quantities raise a host of unsettling questions. Are they truly constant? In what way are they ‘fundamental'? Why do they have those particular values? What do they really tell us about the physical reality around us? - *** - "In 1899, Max Planck, who founded quantum physics, examined the relations among h, c and G and the three basic aspects or dimensions of physical reality: space, time, and mass. Every measured physical quantity is defined by its numerical value and its dimensions. We don't quote c simply as 300,000, but as 300,000 kilometres per second, or 186,000 miles per second, or 0.984 feet per nanosecond. The numbers and units are vastly different, but the dimensions are the same: length divided by time. In the same way, G and h have, respectively, dimensions of [length3/(mass x time2)] and [mass x length2/time]. From these relations, Planck derived ‘natural' units, combinations of h, c and G that yield a Planck length, mass and time of 1.6 x 10-35 metres, 2.2 x 10-8 kilogrammes, and 5.4 x 10-44 seconds. Among their admirable properties, these Planck units give insights into quantum gravity and the early Universe. - *** - "Perhaps the most intriguing of the dimensionless constants is the fine-structure constant ?. It was first determined in 1916, when quantum theory was combined with relativity to account for details or ‘fine structure' in the atomic spectrum of hydrogen. In the theory, ? is the speed of the electron orbiting the hydrogen nucleus divided by c. It has the value 0.0072973525698, or almost exactly 1/137..... - "But no one has yet explained the value 1/137, a number with no obvious antecedents or meaningful links. The Nobel Prize-winning physicist Richard Feynman wrote that ? has been ‘a mystery ever since it was discovered… a magic number that comes to us with no understanding by man. You might say the “hand of God” wrote that number, and “we don't know how He pushed his pencil”.' - *** - "Perhaps it isn't possible for the intellect to overcome a sense of the arbitrariness of things. We are close here to the old philosophical riddle, of why there is something rather than nothing. That's a mystery into which perhaps no light can penetrate." - Comment: Note, no explanation for why things are the way they are.