johnsankey

studiot: Anything that is self-consistent can be mathematics. Physics is built on observables, reality. My view was settled when I was able to observe a single ion of barium (and prove it) then play Maxwell's daemon to the outer electron of that ion. Everything was as real as golf balls. No forever-dancing mystics, no jumps faster than light, no worlds multiplying without limit... That's why I skip mathematical dream states now, and stick strictly to observables. Mathematics doesn't support physics, it only tries to model it. swansont: to me the work of Shannon makes the connection between entropy and information obvious. I'll see if I can sort out an approach that would be a 'credible source', since you obviously feel I'm not one.

swansont: To a mathematician, all 3 formulations say the same thing. However, I'm a physicist who focuses on reality, what I can observe. To me (with a twinkle in my eye 😉): One formulation, due to Schrödinger, is based upon space-time, wave patterns, and makes the universe look continuous. Like, really continuous. Schrödinger functions have no boundary - each one fills all of possible space if you wait long enough. A second, Heisenberg, is based upon observable energy movement, quantum jumps, and makes the universe look like particles. In this view, all particles but one are made of other particles - the universe is the ultimate particle. The third, Everett, is based upon information, and makes the universe look sensible - like we think we are. My human analogy of the cat is based on Everett's formulation; I'm not claiming that the E. formulation "says it". I hope that helps you to understand my approach; of course you don't have to agree with it!

Schrödinger, Heisenberg and Everett are mathematical formulations of QM. They are formulations, not separate theories, because they are exactly equivalent mathematically. Any criticism of one is a criticism of them all.

As entropy increases, information content decreases.

First, we set up conditions so that a particle can "split into two". This constitutes an observation, and both halves of the split particle remain local to this first observation. When the properties of one of the split particles is determined, a second observation, the joint wave function is resolved to describe both particles, simultaneously with reference to the space-time at the now-determined point of split. If we were not aware of (observe) the condition that provided for particle splitting, we would not be aware of any correlation until we inferred the existence of that condition by repeated observation. That would then be in effect a first observation.

A photon does not have rest mass, but it's energy gives it a mass in general relativity. That's why it's affected by gravitation. Light is energy in e=mc2 ; of course it has other properties too.

Time is defined by quantum mechanics. A photon with energy h (Planck's constant) behaves as though it were oscillating once per second. That's a definition. Atomic clocks are based on this. Time is also defined by general relativity. Our earliest measures of time were the duration of one rotation of the earth relative to the sun, a rotation of the moon about a point on the earth, and of the earth around the sun in inertial space, measures based on general relativity. These were built into the genetic heritage of all life long before human beings arose. We still use them today, as our day, month and year. By 1700, pendulum clocks showed that there were variations of about 50 seconds in the duration of a solar day. For the first time, mechanically measured time took precedence over astronomical time; remember, however that both are based upon general relativity. Time direction is based on information, which has long sat uneasily in the world of mathematics, because it exists only as a collective property. One quantum by itself can not have a time direction. But, any multi-quantum system must have an arrow of time. The essence of quantization is that information is limited - many 'different' particles are indistinguishable. We can not distinguish one electron from another, we can only observe the recent history of each one as reflected in its few quantum numbers. With quantization and its consequent limitation of information, a closed universe progresses from an ordered state to a disordered state - a direction of time. And, when the number of particles is large, even as large as the number of molecules in a cubic millimetre of air, the disordered state is permanent, compared to the apparent lifetime of our universe anyway. We can't put things back the way they were, because we can never know how to do it. StarTrek-inspired teletransport of people will face the same limitation. This, of course, is the 2nd law of thermodynamics - entropy is information with the sign wrong. Space-time is also dissipative with respect to information: the information obtainable from an object moving away from us is progressively reduced as its speed approaches the speed of light; anything heading away from us at the speed of light is no longer observable. A direction of time is implicit in general relativity. Gravity is asymmetrical and self-reinforcing, and the appearance of a black hole (at this point in time, anyway) is irreversible. So, contrary to the view of many physicists whose formative years were spent solely with classical mechanics, time direction seems to be inherent in all aspects of our universe.

Here is a human analogy of Schrödinger's cat: Suppose that your significant other is visiting the next town and, on the radio, you hear that half that town has been blown up by a gas leak. By the time you hear the news, your other is only in one state. One way or another, the explosion is complete. But, you sure aren't in one state! Half of you is worried that your bed won't be warm tonight, the other half is worried that the breakfast argument will be continued at dinner. You phone your nurturing parent for some solace, and promptly create a pair of worlds at the other end of the telephone line... Finally, you get that phone call, from your s.o. or from the police. One way or another, you make your quantum jump and one of your states (worlds) dissolves from reality. Gradually, your family and friends follow suit as they talk to you. Of course, years later, you can still run into someone who asks "Did your ? ?" But, once everyone who interacted with any of you when you were in two pieces (in superposed states) has heard the news, or has passed on to that other world, your world is back to being one again with regard to that particular matter. That's what happens to quantum particles. Quantum worlds fade from existence as fast as new ones are created. Schrödinger's cat is in one state - it's us, our knowledge, outside the cat's closed box that's in two states. But you'd never guess that from Schrödinger's formulation. You have to follow the information. An 'observer' can be as small as a single radioactive nucleus - things our size and complexity are not required. In fact, any two even partially-correlated quanta can 'observe' another single quantum. In the limit, quantum mechanics is a continuous function.

Yes. cf. url deleted by moderator

Space-time, Minkowski vectors, is mathematics not physics. To be mathematics, all you have to be is logically consistent. To be physics, it has to be observable.

e=mc2 light is energy Gravity does indeed have an effect on light: search 'gravitational lensing'

Entanglement does not transfer information if you stick to observables rather than mathematics. Details here: url deleted

I know using the Everett formulation of QM, based upon knowledge, isn't popular but it really does simplify a number of questions that are confusing with the other formulations. If you follow the information, Schrödinger's cat is in one state, either alive or dead - it's us, our knowledge, outside the cat's closed box that's in two states because we don't know. I discuss this in more detail at url deleted