Hijack from Jumping out of the black hole, What about the event horizon? From nowhere to everywhere.

[Genady]

26 minutes ago, Lorentz Jr said:

That's math. I was talking about physics.

The main point, to me, is that mathematics has explanatory power.

Regarding math vs physics, they are perceived differently on the level where our perceptions are connected to our senses. As we go down the turtle levels, the distinction becomes less evident. I see a possibility that turtles are not all the way down, but rather the last level of turtles is just math. There, the mathematical explanations are the explanations.

[studiot]

1 hour ago, Lorentz Jr said:

No.

And ?

[Lorentz Jr]

3 hours ago, studiot said:

Have you ever heard of the equations of constitution and compatibility  ?

2 hours ago, Lorentz Jr said:

No.

58 minutes ago, studiot said:

And ?

And I couldn't find anything about them in a quick internet search.

[studiot]

1 hour ago, Lorentz Jr said:

And I couldn't find anything about them in a quick internet search.

 

So it is good that you are interested enough to look.

However I also said more about them than in your quote of my words.

4 hours ago, studiot said:

In relation to your original comment that cause this thread.

 

4 hours ago, studiot said:

This is a very convenient way to divide up the maths. Compatibility is very often represented by some geometrical constraint.

 

Note I was bringing in your comment on geometry.

I was not disagreeing with it.

 

On 3/11/2023 at 9:47 PM, Lorentz Jr said:

The same kind of magic wand you physicists wave with the word "geometry".

So spacetime has a geometry. So what? Lots of things have geometry. Geometry is just a mathematical description. It doesn't mean fields and gravity waves happen by magic or unicorns or leprechauns. It doesn't mean spacetime isn't implemented by something that an amateur might call a "fabric" or "ether".

 

Since I thought you and others might be interested

The equations of constitution are the controlling statements or principles, preferably in the form of equations, in physics, chemistry or the science of interest, that are being invoked or brought into play.

For example Newtons Laws of motion.

Bernoullis's equation in fluid mechanics.

The Law of mass action in chemistry.

The electrochenical series in chemistry

The differential equations of displacement of a loaded beam.

Hopefully you get the idea.

 

But these equations are applied to real systems they have no meaning in isolation.

And real systems introduce constraints of their own.

Many of these constraints are geometric ones, others may be conservation laws.

So we often pair

the continuity equation (conservation of mass) with Bernoulli

conservation of charge with calculations on chemical reactions.

 

Such equations are called the equations of compatibility.

But as I said they need not be actual equations for instance we have the beam displacements at the supports must = zero to pair with the beam differential equation for which there are many mathematical solutions, and we must pick a solutions that satisfies the compatibility condition.
This particular example is a simplified version of the basis of quantum mechanics, wher we must pick integer solurions to fit some system geometry.

 

Are you beginning to get the idea ?

 

 

 

 

 

Edited March 15, 2023 by studiot

[Lorentz Jr]

37 minutes ago, studiot said:

Are you beginning to get the idea ?

Fundamental principles vs details of the problem at hand. Got it. 🙂

[studiot]

1 minute ago, Lorentz Jr said:

Fundamental principles vs details of the problem at hand. Got it. 🙂

More or less yes, but you need both it is not a question of versus.

Also sometimes fundamental principles are enough.

Most times they are not.

As for example in the phrase 'statically determinate'

In two dimensions there are three fundamental equations available.

After that you must introuduce others somehow if they are not enough - which is mostly true in real life.

[swansont]

6 hours ago, Lorentz Jr said:

Derivations of the Lorentz transformations define localism in terms of a single speed limit that applies to all phenomena in the entire universe. That definition seems unnecessarily restrictive to me. After all, nobody complains that c is greater than the speed of sound. Light is defined at a lower level of abstraction than sound, so it's acceptable for it to be faster.

Your opinion in this matter is irrelevant. The issue was establishing the claims of mainstream physics.

The basis of the derivation is the invariance of c (based on electrodynamics) and the variable in question is time. 

 

 

[joigus]

20 hours ago, studiot said:

The discovery of penecillin was a pure accident, no cnjecture, bold or otherwise was involved.

Don't forget the Flemings of the Stone Age:

Quote

Neanderthals dosed themselves with painkillers and possibly penicillin, according to a study of their teeth. One sick Neanderthal chewed the bark of the poplar tree, which contains a chemical related to aspirin. He may also have been using penicillin, long before antibiotics were developed.

 

[Markus Hanke]

18 hours ago, Lorentz Jr said:

That's circular reasoning, and I've finally lost patience with the excuses that people keep making for it.

I honestly don’t think that anything that works as well as SR requires excuses to be made for it - unless of course you demand something from it that it wasn’t ever designed to do. But regardless, this is a discussion forum, so we can agree to disagree on that.

It’s kind of like using a topographical map. Prior to joining the monastery I used to be big into thru-hiking and long-distance backpacking, and would always carry a paper map when I went into the backcountry. You can pick two points on such a map, and decide by which route you want to connect them, and the map will then tell you how far you have to go along that route. Now, the map obviously isn’t the territory, so why does this work so well? It works because the relationship between points on the map is the same as the relationship between locations in the “real” territory - two map-units exactly map into two territory-units, using a known conversion constant. It’s a faithful representation of relationships between locations in the territory. It would be meaningless to ask here by what “mechanism” something “acts” on your ruler to “make it” measure different distances along different routes on your map. Once the map is open on your lap, you just pick a route and read off the answer - at that point it’s just geometry, and there are no mechanisms or effects that act on anything. What is meaningful though is to ask why the relationships between locations in your territory are what they are - the answer to this might include geological processes, erosion due to weather etc. But of course your map can’t provide you with such information, because it was never designed to do that; it just represents what’s there right now. That doesn’t make it any less useful for your hike, and you wouldn’t need to “make excuses” for the map on account of that omission, would you?

SR/GR is no different - it’s a faithful map-like representation of the relationships between events (locations in space at instances of time) in the real world. Once you pick two events and decide which route you wish to take between them, it will tell you how long that route will be. Just like on an ordinary map, different routes will naturally be of different lengths, and just like on a real map, that requires no mechanisms that act on your measurement devices to make that so. The reverse is just as true - if you measure different lengths between the same events, you know that different paths were taken. So SR/GR is about relationships between events, not about things somehow “happening” to those events. And just like on the map, it is indeed meaningful to ask why these relationships are what they are, which is the closest you’d get to having a mechanism - no one knows the answer to this just yet, but one possible answer could be that classical spacetime emerges from something more fundamental, according to its own set of rules and dynamics, just like surface topography on Earth emerges from plate tectonics and other geological processes. There’s no guarantee that this is so, but it’s a possibility that is testable at least in principle. But whatever the case may be, the answer would be outside the paradigm of SR/GR, in the same way as plate tectonics is outside the paradigm of a topographical hiking map.

So IMHO, answering the question as to differing readings of travelling clocks in terms of spacetime geometry is perfectly reasonable, in the same way as it is perfectly reasonable to answer the question as to differing route lengths in terms of the Euclidean geometry on a topographical hiking map. These measurement differences - again IMHO - require no other causative mechanism; once the map is in front of me, the distances are a foregone conclusion, I just need to read them off, and I can rely on the fact that the distance I actually have to walk in the real world will coincide with what the map tells me, without wondering what mechanisms might act on my feet to make these numbers match. I think we can all agree that if there is a deeper reason as to why these geometries are what they are, then of course we want to know about it and understand it. But that’s a different paradigm, and provides answers to a different set of questions, and it isn’t something we can reasonably expect SR/GR to be able to do. When I ask how long I will have to walk to get to tonight’s camp spot, then I don’t want to get an answer in terms of plate tectonics - even if that is the ultimate mechanism, the answer would be essentially useless to me.

So that’s just my own two cents on this subject - no one is under any obligation to adopt this type of philosophy, but I find it reasonable and it works for me.

[crowman]

Would it be fair to say that 'reality' certainly acts like space-time is a non-euclidean curved manifold, and that physics can't show that it's not? I don't know if that's a catch 22 or not?

[Genady]

Here is a little thought experiment.

One of the twins stays on Earth. Another goes away for space travel, visits many places, experiences many environments, etc. When the traveler finally comes back to Earth, after 30 years, they discover that somehow, miraculously, they aged exactly the same! Wouldn't it be strange? Wouldn't it require a mechanism to explain how such synchronicity could happen?

[Lorentz Jr]

2 hours ago, Markus Hanke said:

I honestly don’t think that anything that works as well as SR requires excuses to be made for it

You're confusing the mathematical theory with the metaphysical principle. The theory doesn't need excuses as long as people remember that it's just a theory. An abstract model that doesn't really explain anything and may be subject to further refinement. Curvature for GR, quantum complications for the ToE, etc..

The principle of relativity is a very different animal. It's only one possible interpretation of the theory. It's a platypus, with time for a nose and space for a tail. The extreme form of the principle says there's no reference frame with any special properties at all, which means time and space are somehow "interchangeable" or "made of the same stuff". That's an extraordinary claim, and as such, it requires extraordinary evidence. That's what people keep making excuses for.

2 hours ago, Markus Hanke said:

- unless of course you demand something from it that it wasn’t ever designed to do.

It's not what I've been demanding, it's what people have been claiming. They claim that SR "explains" things, but it doesn't. It's a shallow, phenomenological model that describes non-gravitational, non-quantum things very nicely, but it doesn't explain a damned thing. It doesn't explain time dilation, it only describes it.

2 hours ago, Markus Hanke said:

But regardless, this is a discussion forum, so we can agree to disagree on that.

Yes, and I'll try to keep my mouth shut about this subject in the future unless someone else brings it up again. It only came up recently because of the "fabric" thing.

2 hours ago, Markus Hanke said:

It’s kind of like using a topographical map.

I'm done with analogies, Markus. Other people may not understand this distinction, but one of the lessons that have been burned into my memory over the last year is that analogies aren't evidence of anything. They're just stories. They don't prove that what the person is saying is true, they only explain what the person is saying. And I understand what you've been saying. If I tell you life is like a bowl of cherries, that may explain how I feel about life, but it doesn't mean I'm right.

2 hours ago, Markus Hanke said:

SR/GR is no different - it’s a faithful map-like representation of the relationships between events (locations in space at instances of time) in the real world.

So, to summarize, this is where we disagree. You can appeal to physical intuition, and you can talk about abstract mathematical models, but it's BS to conflate the two ideas. From an intuitive physical point of view, a "map" with time in it is very different from a map with only spatial dimensions. That's the lie of trying to "explain" time dilation by calling it "just a matter of geometry". Representations are mathematical models, not physical explanations, and the things that people intuitively understand as "maps" are only about space, not time.

2 hours ago, Markus Hanke said:

So that’s just my own two cents on this subject

It's your two cents, and it's also the two cents of almost everyone else in the physics community. So the question is, why do I seem to be the only weirdo who doesn't believe in the principle of relativity but still believes in physics? I feel like I've gone from arguing with anti-establishment trolls on one website to arguing with pro-establishment trolls on another site! That's my two cents. 🙂

2 hours ago, Genady said:

Wouldn't it require a mechanism to explain how such synchronicity could happen?

Sure, but any relationship requires a mechanism, and any nontrivial one requires a preferred reference frame to account for the traveler's motion.

Edited March 16, 2023 by Lorentz Jr

[Eise]

Hmm, @Lorentz Jr, I am wondering what for you a good, physical explanation is. Can you give a few examples of basic physical laws that count for physical explanations for you?

1 hour ago, Lorentz Jr said:

You're confusing the mathematical theory with the metaphysical principle.

Metaphysical? What do you mean? How nature is behind the physical laws? But yeah, that would be metaphysics, not physics, wouldn't it?

1 hour ago, Lorentz Jr said:

Representations are mathematical models, not physical explanations

So giving a few examples could help: for me these are more or less the same.

[martillo]

4 hours ago, Genady said:

Here is a little thought experiment.

One of the twins stays on Earth. Another goes away for space travel, visits many places, experiences many environments, etc. When the traveler finally comes back to Earth, after 30 years, they discover that somehow, miraculously, they aged exactly the same! Wouldn't it be strange? Wouldn't it require a mechanism to explain how such synchronicity could happen?

Someone said otherwhere the "proper time" is the same for any observer. Can it be said that "proper space" is also the same for any observer? Then would follow that "proper space-time" is always just an Euclidian flat space and an absolute time the same as in Classical Physics. The "space-time curvature" would be just apparent to the observers. The problem with this is that Relativity Theory becomes just an "apparent theory" describing things that actually does not take place anywhere. This is not what is sustained by the mainstream. It is said for instance that time dilation is real with the example of the muons' decay as an experimental proof for RT. Something does not match to me here...

Edited March 16, 2023 by martillo

[Genady]

2 minutes ago, martillo said:

Then would follow that "proper space-time" is always just an Euclidian flat space and an absolute time the same as in Classical Physics.

No, it would not. Perhaps you misunderstood what 'the "proper time" is the same for any observer' means. What do you think it means? In my understanding of it, time dilation is 'real'.    

5 minutes ago, martillo said:

Something does not match to me here...

Yes, your understanding of proper time.

[martillo]

6 minutes ago, Genady said:

No, it would not. Perhaps you misunderstood what 'the "proper time" is the same for any observer' means. What do you think it means? In my understanding of it, time dilation is 'real'.    

Yes, your understanding of proper time.

Why have you presented that thought experiment where there's no time dilation then? I don't get it. Some time dilation must have happened and the twins would not present the same age at the end in your example:

3 hours ago, Genady said:

Here is a little thought experiment.

One of the twins stays on Earth. Another goes away for space travel, visits many places, experiences many environments, etc. When the traveler finally comes back to Earth, after 30 years, they discover that somehow, miraculously, they aged exactly the same! Wouldn't it be strange? Wouldn't it require a mechanism to explain how such synchronicity could happen?

 

[Genady]

2 hours ago, Lorentz Jr said:

Sure, but any relationship requires a mechanism, and any nontrivial one requires a preferred reference frame to account for the traveler's motion.

Sounds like dogma to me. Let's call it, research program. You seem to like this research program. I seem to dislike it. A matter of taste. Which research program will go farther, is a different matter.

6 minutes ago, martillo said:

Why have you presented that thought experiment where there's no time dilation then? I don't get it.

Yes, you don't. But Lorentz Jr. does.

[martillo]

23 minutes ago, Genady said:

Yes, you don't. But Lorentz Jr. does.

I apologize, it wasn't you that said that the "proper time" is the same for any observer. Actually seems it isn't the case. May be it applied for a special case only. Searching about the concept now...

Edited March 16, 2023 by martillo

[TheVat]

On 3/12/2023 at 4:39 AM, Markus Hanke said:

think you are demanding way too much from contemporary physics - you seem to basically say that “if it isn’t a fully fledged ontological explanation, then it’s not science”. I cannot agree with this. I think any epistemic description of an aspect of the world that allows us to make predictions by way of computation is valuable, at least as an intermediary step, even if it is not explicitly ontological in nature. Of course we want such models to approach the status of an ontological explanation over time, but that is not going to happen all at once

Maybe approach is our natural epistemic condition.  Lagrange took a nice step in getting rid of constraint forces (his rigid pendulum rod, e.g.) as @Genady mentioned, and his step was towards describing a system's energies,  a function which summarizes the dynamics of the entire system.  For my limited understanding of physics, it seems like "force" can be a move away from sound ontology.  (it is fine for moving furniture)  And energy and Riemannian curvature seems, oddly, less abstract and more towards ontological terra firma.

[Genady]

6 hours ago, crowman said:

Would it be fair to say that 'reality' certainly acts like space-time is a non-euclidean curved manifold, and that physics can't show that it's not? I don't know if that's a catch 22 or not?

You mean, non-Minkowskian rather than non-Euclidean. The latter could apply only to space.

Alternatively, it would be fair to say that space-time is Minkowskian but gravity affects all rulers and clocks in such a way that measured distances and times are distorted. Einstein field equation describes these distortions. 

[swansont]

8 hours ago, Lorentz Jr said:

The extreme form of the principle says there's no reference frame with any special properties at all, which means time and space are somehow "interchangeable" or "made of the same stuff". That's an extraordinary claim, and as such, it requires extraordinary evidence. That's what people keep making excuses for.

People went looking for that frame with special properties and they couldn’t find it. We are not moving with respect to it nor are we at rest in it. The experimental evidence is that it doesn’t exist. 

The extraordinary thing here is the idea that one can make a claim that there’s a preferred frame but retreat at any request for evidence in support of the claim.

[crowman]

2 hours ago, Genady said:

You mean, non-Minkowskian rather than non-Euclidean. The latter could apply only to space.

Yes, you're right, thanks.

2 hours ago, Genady said:

Alternatively, it would be fair to say that space-time is Minkowskian but gravity affects all rulers and clocks in such a way that measured distances and times are distorted. Einstein field equation describes these distortions. 

On Earth, a thrown stone will naturally take a path that results in maximum ageing between launch and impact. The stone didn't read a clock or use a ruler.

I only say this because your  "gravity affects all rulers and clocks" leaves the backdoor open to calls of "it only affects the instruments of measurement."

[Genady]

44 minutes ago, crowman said:

I only say this because your  "gravity affects all rulers and clocks" leaves the backdoor open to calls of "it only affects the instruments of measurement."

Since everything that has dimensions and/or duration can be, in principle, a ruler / a clock, it equally affects everything like this.

[Markus Hanke]

19 hours ago, Lorentz Jr said:

The extreme form of the principle says there's no reference frame with any special properties at all, which means time and space are somehow "interchangeable" or "made of the same stuff".

Yes, it means that all inertial observers experience the same laws of physics.

19 hours ago, Lorentz Jr said:

That's an extraordinary claim

Is it? I see it simply as an empirical observation, which was part of what motivated the development of SR in the first place. We have never once seen any evidence whatsoever (within the domain we can experimentally probe) that would contradict this. The known constraints on violations of Lorentz invariance are indeed extraordinarily stringent.

19 hours ago, Lorentz Jr said:

From an intuitive physical point of view, a "map" with time in it is very different from a map with only spatial dimensions.

Clearly my intuition is very different from yours, since to me it is intuitively obvious that a Euclidean map with only spatial dimensions in it cannot and does not accord with what we actually observe in the world around us, except perhaps as an approximation in the classical non-relativistic regime (i.e. “high school physics”). Again, historically this was one of the motivating forces behind the development of SR in the first place. So “intuition” is a rather poor guide, since it is highly subjective.

20 hours ago, Lorentz Jr said:

So the question is, why do I seem to be the only weirdo who doesn't believe in the principle of relativity but still believes in physics?

Maybe because “belief” is just as poor a guide as “intuition” is.

[Lorentz Jr]

On 3/16/2023 at 7:14 AM, Lorentz Jr said:

You're confusing the mathematical theory with the metaphysical principle.

The principle of relativity is a very different animal.

The extreme form of the principle says there's no reference frame with any special properties at all, which means time and space are somehow "interchangeable" or "made of the same stuff".

4 hours ago, Markus Hanke said:

Yes, it means that all inertial observers experience the same laws of physics.

No, the strong form of the principle (at least as interpreted by some people) means more than that. It goes beyond what observers experience and claims that there's nothing "under the hood", i.e. that no mechanism is required for time dilation because it's "just a matter of geometry".

Anyway, I don't know how to explain this distinction more clearly, so let's drop the subject. We're repeating ourselves.

On 3/16/2023 at 7:14 AM, Lorentz Jr said:

That's an extraordinary claim, and as such, it requires extraordinary evidence. That's what people keep making excuses for.

4 hours ago, Markus Hanke said:

Is it? I see it simply as an empirical observation

Same thing. I criticize the metaphysical principle, and you respond by defending the mathematical theory. We're talking past each other.

On 3/16/2023 at 7:14 AM, Lorentz Jr said:

So, to summarize, this is where we disagree. You can appeal to physical intuition, and you can talk about abstract mathematical models, but it's BS to conflate the two ideas.

4 hours ago, Markus Hanke said:

Clearly my intuition is very different from yours, since to me it is intuitively obvious that a Euclidean map with only spatial dimensions in it cannot and does not accord with what we actually observe

Yes, that's very different from both ordinary human intuition (maps are about space, not time) and the intuition of 19th-century physicists (science is about mechanisms). Most people outside the modern physics establishment would say that simple comparisons of observational data and theoretical predictions only require the ability to read charts and compare numbers and have nothing to do with intuition.

On 3/16/2023 at 7:14 AM, Lorentz Jr said:

So the question is, why do I seem to be the only weirdo who doesn't believe in the principle of relativity but still believes in physics?

4 hours ago, Markus Hanke said:

Maybe because “belief” is just as poor a guide as “intuition” is.

Maybe so, although I'm not sure how new theories of any kind at all can be developed without some general principles or opinions to guide the theorists.

Anyway, let's forget about the ether for now. I've been reading about emergent spacetime, and that looks like it may be close enough to what I have in mind.

Edited March 17, 2023 by Lorentz Jr