Does True Randomness Actually Exist? ( ^&*#^%$&#% )

Whoa!

Causality doesn't move anywhere (or anywhen), any more than the conservation of energy does. It's a word referring to a very general law of nature.

That law says that information only moves into the future light cone.

The notion that you have in mind is that this might not be so. Good luck with that: perhaps you can refute the law of conservation of energy next.

(Note that moving "forward in time" is insufficiently precise, because you can have a point in space-time that is forward in time - i.e. its time is later - compared to another in some chosen frame, but which cannot be communicated with (because its distance is greater than how far light or anything else can travel in the time difference. This is part of the "neither" regions in my diagram).

You are appallingly boorish!

Bercher was right - this is nothing more than a problem with using a word with two definitions.

I stated and used the meaning of causality used in physics, which provides the answer to the once open philosophical question of the constraints on cause and effect.  To quote the introduction to the wiki article on Causality - "While causality is also a topic studied from the perspectives of philosophy, from the perspective of physics, it is operationalized so that causes of an event must be in the past light cone of the event and ultimately reducible to fundamental interactions. Similarly, a cause cannot have an effect outside its future light cone."

i.e. philosophy may treat this as a question, but physics has provided the answer. You are taking the philosophical viewpoint and a definition that ignores the existence of the physics.

It's easy to say "but what if this wasn't true", but in science when you have a universal law that works without exception you need a reason to throw it away (otherwise you just throw away all the knowledge you have).

It would be legitimate, for example, to propose an experiment to violate causality and verify that this has happened. Testing a time machine would suffice.

You may need to increase it to more than a century - the discovery of relativity is older than that.

Causal Determinism
First published Thu Jan 23, 2003; substantive revision Thu Jan 21, 2016
Causal determinism is, roughly speaking, the idea that every event is necessitated by antecedent events and conditions together with the laws of nature. The idea is ancient, but first became subject to clarification and mathematical analysis in the eighteenth century. Determinism is deeply connected with our understanding of the physical sciences and their explanatory ambitions, on the one hand, and with our views about human free action on the other. In both of these general areas there is no agreement over whether determinism is true (or even whether it can be known true or false), and what the import for human agency would be in either case.

Not sure when the terminology arose, but the concept was clear from the outset.

I would say the time this would have been so is in 1907 when Minkowski published his formulation of special relativity, where the light cones are more prominent.

While I quoted the word "operationalism" that is not one I would ever use myself. It was the rest of the quote I was drawing attention to.

Sorry, but it's ridiculous to claim the light cone concept obscures anything. It is a clarifying concept to most people (certainly me).

Our discussion made me realise it would be better to refer to the light cone as the "causal cone".

The technical reason I prefer this is that when there is a medium, the actual light cone is distinct from the causal cone because the effective speed of light is always lowered.

I am not 100% sure if the speed of gravitational waves changes when they pass through a medium. I can find no confirmation that it does, but it is also possible to reason that since photons are delayed by interaction with electrically charged particles, gravity might be delayed at least slightly by interaction with energy/mass. But the analogy is not perfect. I can be sure any slowing is remarkably tiny due to beautiful observations like those of a neutron star merger in both gravitational waves and gamma radiation!

Gravity

“the universal force of attraction acting between all matter”

No such force exists
Think hard about it
If all matter is attracted to all existing matter by a “force “- the universe would not be as observed.

Gravity is generally regarded as the least understood force in nature. That is because it is not a force at all-  But rather acts within a medium not yet understood.
It is a property of mass and should not be seen as “an attractive force”.

lol texting random people that message 

Space-time curvature exists. It permits pulses of waves containing as much energy as hundreds of suns produce in their entire lifetimes to travel across billions of light years and to be detected in detail in gravitational wave observatories on Earth, despite the fact that this only causes changes in lengths of about 1% of the diameter of a proton.

The prediction and confirmation of the distortion of space-time caused by such waves (and the multidecade international effort to detect them, 100 years after the theory that predicted them was published) shows that gravity is understood extremely well at all but the very highest energies.

@Optimissed, I understand there is a lot of interest these days in explaining gravity and indeed the existence of space time as a consequence of entanglement called "emergent gravity"!

It's not a metaphor, it's a mathematical model that perfectly fits observations. Like Euclidean geometry is a great classical description of the space in your living room, that embodies the relationships between distances that is unique to that geometry. If you can find a better way of describing the truth, well, you'd be achieving the impossible.

The idea that you can view time as separate from space is simply incorrect. It is a fundamental result of relativity that, for example, the dimension that one observer perceives as time is a mixture of what another sees as time and what they see as space. There is no way to escape this mathematical fact about real observations.

It's not very different to the ideal that in (classical) space there are separate up/down, left/right and forward/backward dimensions. The truth is that what you see as up/down depends on your orientation and is a mixture of the dimensions for a different observer.

Fundamentally the thing that is at the core of both scenarios is that there is a group of symmetries under which the laws of physics are preserved. In classical space it is the group of Euclidean isometries (rotations, reflections) and in relativity it is the Lorentz group (the isometries of Minkowski space).

opti:"The neutron star merger is very interesting. On a journey of 130 million light years, gravity waves were 1.7 seconds quicker than light waves overall. I would take that as meaning that the nature of light is such that it is more prone to interference from the surroundings which it passes through than is gravity. What surprises me is the smallness of the difference and I would guess that perhaps the space between the collision and Earth is not particularly "busy" and there were few densely populated galactic centres to pass through. That's only a guess, of course."

my guess is that your centres were made out of glass.. lol. 

but really.. why do you prefer gravity as interactions between matter rather then an "aether like" field or whatever that interact localy with matter and capable of curvature structure like?

I am rather sure you do not think the same as Minkowski.

Physics is about mathematical models of reality that work (make correct predictions). Physicists have long discarded the impossible aim of finding something else, because there is no way for the scientific method to distinguish anything else.

Curvature is a description of the mathematical relationship between distances.

Metaphors are ambiguous, imprecise analogies used in the arts. Physics uses mathematical models which are unambiguous and precise in what they say about predictions. They are good models if they work, not if they don't - pragmatic rather than aesthetic criteria.

Yeah, tell those cosmologists. They are such fools.

(I have to say it makes no sense at all to me. There is no part of the Big Bang model that is steady state. It involves rapid change in temperature and density at every time).

The curvature of space-time is exactly as real as the curvature of the Earth's surface. It's a fact about the relationship between different measurements. You can call the curvature of the Earth's surface metaphorical if you want, but you should go to the Arts faculty first.

The "distortion" is the relationship between different measurements. Nothing more, nothing less. Of course, this relationship allows precise prediction of anything that happens, such as the precise ways that objects move in orbit (very close to Newtonian approximation) and how their clocks are affected (entirely new in relativity).

The "exact nature of the distortion" is known to a precision of 1 part in 10^15 in some cases. There are no presently possible experiments that are able to distinguish between the predicted distortion and that which occurs, and it is not clear whether there ever will be.

The "distortion" is the relationship between different measurements. Nothing more, nothing less.

"Do you know what I meant by galactic centres being densely populated?"

maybe. what i think you meant is that if light/photons would hit a busy path i.e matter,  they would never even reach our detectors on earth because they would either get absorbed or scattered by the obstacles.

my own first thought was that 1.7sec delay over such a long journey is neglectable. but then..  1.7s delay for light means that it had to pass thru something clear, like air or glass. going thru say glass, means it pass several 100's thousands km of glass. thats a lot of glass.. lol. my next thoughts were too trippy to post..

"Unfortunately, quantity isn't quality. One meaning of that is that something can be measured whilst not being understood."

that's true for a whole lot of our human experience..  time, space, QM, consciousness, etc.. even life itself.