Quantum Gravity

[whollygoats]

So...skepticalbip.

Can you describe to me 'quantum entanglement' such that I would understand it? I understand that this is also known as 'spooky action at a distance'.

I can give a simple description but can't guarantee you would understand it.

The very first thing is, forget the nonsense that pseudoscience has claimed about it. Start with a clean slate as if you had never heard the term "quantum entanglement".

If a pair of particles are created in an energetic event then they will have complimentary quantum numbers because of conservation principles. i.e. if one is a spin up quantum state then the other will be in a spin down quantum state. That is, the two particles are entangled. Change the state of one of the particles and they are no longer entangled.

Entanglement is simple. The problem is in interpretations because of other QM principles.

Okay....'conservation principles'. What determines those? Why is that necessarily so?

'an energetic event'...how is such an event created?

'change the state'...how does that happen?

'particles'...of any kind?

My impression of your explanation is that all of this happens at a scale beyond typical measurement and under very controlled circumstances. I'm not sure how these quantum events affect the development of a reality.

 

[skepticalbip]

So...skepticalbip.

Can you describe to me 'quantum entanglement' such that I would understand it? I understand that this is also known as 'spooky action at a distance'.

I can give a simple description but can't guarantee you would understand it.

The very first thing is, forget the nonsense that pseudoscience has claimed about it. Start with a clean slate as if you had never heard the term "quantum entanglement".

If a pair of particles are created in an energetic event then they will have complimentary quantum numbers because of conservation principles. i.e. if one is a spin up quantum state then the other will be in a spin down quantum state. That is, the two particles are entangled. Change the state of one of the particles and they are no longer entangled.

Entanglement is simple. The problem is in interpretations because of other QM principles.

Okay....'conservation principles'. What determines those? Why is that necessarily so?

It is determined by nature. We recognized conservation was "a thing" through observation then modeled that observation in our mathematical model. Why is a pseudoscience question as in, "why did god decide to do it that way?". Science observes the way reality is, accepts it, and models it.

'an energetic event'...how is such an event created?

Many ways but observation of such things is generally caused by collisions in a cyclotron.

'change the state'...how does that happen?

expose the particle to an electric or magnetic field or even collision with another particle.

'particles'...of any kind?

What exactly are you asking?

My impression of your explanation is that all of this happens at a scale beyond typical measurement and under very controlled circumstances. I'm not sure how these quantum events affect the development of a reality.

Again, WTF are you talking about? I explained what science means by "quantum entanglement". The fact that pseudoscience makes asinine claims even extending to ESP and angels is your problem if you want to believe them.

 

[whollygoats]

Okay....'conservation principles'. What determines those? Why is that necessarily so?

It is determined by nature. We recognized conservation was "a thing" through observation then modeled that observation in our mathematical model. Why is a pseudoscience question as in, "why did god decide to do it that way?". Science observes the way reality is, accepts it, and models it.

'an energetic event'...how is such an event created?

Many ways but observation of such things is generally caused by collisions in a cyclotron.

'change the state'...how does that happen?

expose the particle to an electric or magnetic field or even collision with another particle.

'particles'...of any kind?

What exactly are you asking?

My impression of your explanation is that all of this happens at a scale beyond typical measurement and under very controlled circumstances. I'm not sure how these quantum events affect the development of a reality.

Again, WTF are you talking about? I explained what science means by "quantum entanglement". The fact that pseudoscience makes asinine claims even extending to ESP and angels is your problem if you want to believe them.

Whoa, whoa, whoa...I have no desire to rationalize ESP or angels or any metaphysical stuff. But it is my understanding that 'particles' differ in nature...photons behave differently than electrons. Are you speaking at that level or even sub-particles of those? This is all complicated to me by the concept of quanta, of which I am unclear. When I learned physics, it was largely classical physics. Nobody even spoke of quantum mechanics, even though it was well-developed by that time. My world of fundamental particles was one of electrons in orbit around a nucleus of protons and neutrons and nobody knew quite why they stayed together as they did. But, they were fundamental building blocks of the universe....I get the impression that since that time, there have been any number of 'but, wait' moments. And, the last I heard, from a physicist who was actually dabbling in 'string theory' was that she found it enormously unuseful. She thought it a terrible tool.

And...asking why a reaction happens is unacceptable in science? Is that right? 'Why' is an inappropriate inquiry?

Frankly, I find that difficult to believe.

 

[bilby]

The problem with 'Why?' is that it has several meanings, and people typically don't need to be particular about which they use.

If I ask 'why are you late?', then the answer may be causal: 'I am late because my bus was cancelled' (but that's not 'why' you are late; It's 'how' you came to be late); or intentional: 'I am late because the bus driver didn't want to get out of bed'.

The idea of intent is missing from modern science. Things fall down because gravity acts upon them. We can describe 'How' - in terms of various theories and hypotheses, such as relativity or gravitons; But at the bottom of it all there is no 'why' - no god has willed that heavy objects should fall, no object desires to be lower than it currently is in a potential well. Humans are natural animists, and our language reflects that. Where I grew up, assigning intent to inanimate objects was built into the dialect - you might say 'That cup doesn't want to be on the table without a coaster'.

Science observes what occurs, and predicts what will occur in future by theorizing about general 'rules' that material objects will always follow. But there is no mechanism to determine 'why', beyond a reductionist approach that simply lists more and more detailed rules until we reach the limit of our understanding. The Standard Model of particle physics is our most detailed theory; It describes all the underlying interactions between a (IMO surprisingly small) collection of 'particles', and from these, we can build up a theoretical model of any observed phenomenon (other than Relativity).

We may well be able to come up with a way to integrate the Standard Model with Relativity, and such a 'theory of everything' is one of the major goals of theoretical physics. But even such a Grand Unified Theory will just be a set of rules that we observe the universe to obey - it won't tell us 'why' those are the rules, and not some totally different rules that we could have imagined in their place.

We may even be able to 'split the quark' and discover an even more simple set of underlying rules that lead to the observed particles of the Standard Model. But still, we will not know 'why' that set of underlying rules exists; It's 'Why' all the way down. As any five year old can tell you, no matter how detailed an explanation you give for 'why' a particular observation occurred, you can ALWAYS as 'why?' about the explanation itself.

Why? is a perfectly good enquiry; But it is one that we can show logically to be always relevant at any level of understanding - that is to say, we can prove that there is no possible situation where we can no longer ask 'Why?'. So it's not so much inappropriate, as it is provably impossible to ever satisfy, and therefore it is uninteresting. Science likes questions that have at least the possibility of an actual and definitive answer.

So rather than ask 'Why' does an electron have a given probability of being in a given location relative to the nucleus of the atom to which it belongs, we simply ask 'How' do we correctly predict its location. Of course, ordinary English speakers often mean 'How?' when they ask 'Why?'. Hence the confusion.

 

[Bomb#20]

So...skepticalbip.

Can you describe to me 'quantum entanglement' such that I would understand it? I understand that this is also known as 'spooky action at a distance'.

I can give a simple description but can't guarantee you would understand it.

The very first thing is, forget the nonsense that pseudoscience has claimed about it. Start with a clean slate as if you had never heard the term "quantum entanglement".

If a pair of particles are created in an energetic event then they will have complimentary quantum numbers because of conservation principles. i.e. if one is a spin up quantum state then the other will be in a spin down quantum state. That is, the two particles are entangled. Change the state of one of the particles and they are no longer entangled.

Entanglement is simple. The problem is in interpretations because of other QM principles.

Entanglement is complicated. There's quite a bit more to it than conservation principles. If you guys want to understand why physicists regard the world as fundamentally different from the pre-quantum view of reality, you're going to need to carefully read through a technical explanation of Bell's Theorem. Kharakov asked me to explain entanglement last year; here's what I wrote:

https://talkfreethought.org/showthr...ed-upon-matter&p=431400&viewfull=1#post431400

You should be able to follow it if you can handle high-school-level trigonometry.

 

[excreationist]

About information travelling backwards in time (quantum eraser)
https://www.youtube.com/watch?v=8ORLN_KwAgs

 

[whollygoats]

Thanks, bilby.

So, does this mean that causation is a passe' concept, then?

 

[skepticalbip]

Thanks, bilby.

So, does this mean that causation is a passe' concept, then?

Causation applies to a series of events. It would be a stretch to attribute the fact that those events always follow conservation laws to a "cause" rather than it is just the way nature is.

A snooker ball striking another will cause the balls to rebound - this is causal. The way they rebound is determined by the laws of conservation of momentum. The question of why momentum is conserved is currently (and possibly always) beyond science so becomes a religious question.

 

[steve_bank]

Thanks, bilby.

So, does this mean that causation is a passe' concept, then?

It means thwey have been reading too much scifi and not enough scince.

One of the eraly experiments shoed a current through a wire casued a magnetic compass needle to move.

The quest was on to d]find a causal connection n how one affected to the other, was there an unknown medium like the aether?

Causation means nothing happens with a physical cause. If you feel like you have been kicked in the ass and you are thrown forward would you assume it just happened without someone's foot?

In electric circuits the causal link is the electron. In light the causal link is photons.

For gravity to have a measurable force of attraction between two objects there has to be a causal link. Otherwise you are on the woo woo choo choo.

Gravitons are a proposed link in gravity, quantized gravity.

Some argue because of quantum uncertainties QM does not require causality. That is a misinterpretation. In QM casual events are predicted as a probability as to where and when.

 

[whollygoats]

I happen to think that 'why' is a perfectly good question. It seeks the answer to the source of things like 'change of state'. I seem to think that asking the question, "Why did this change states?", when one of our local 'scientists' seems intent on dissuading me from even asking such a question. If one has 'energetic events' occurring, and one does not know why those events are occurring, it seems to me that finding the cause of the energetic events would be on the top of the list about ascertaining as much about the event as possible. 'How' is worthwhile, as are 'when' and 'where', but I think that a fuller explanation of 'why' would be far more enlightening. And then, as noted to me earlier, there is always the possibility of answering the inquiry with, "We don't know yet." Sometimes with, "We don't know if we ever will." But it seems that, "We're still curious as to what it is that causes this to occur and provide a fuller explanation of why it occurs as it does," is a more appropriate approach than denying all usefulness of asking 'why'.

 

[skepticalbip]

The "why question" is far from useless. It is the bread and butter of several fields of "inquiry". Those in the fields of philosophy, religion, and pseudoscience make a damned good living by asking and answering it.

 

[steve_bank]

I happen to think that 'why' is a perfectly good question. It seeks the answer to the source of things like 'change of state'. I seem to think that asking the question, "Why did this change states?", when one of our local 'scientists' seems intent on dissuading me from even asking such a question. If one has 'energetic events' occurring, and one does not know why those events are occurring, it seems to me that finding the cause of the energetic events would be on the top of the list about ascertaining as much about the event as possible. 'How' is worthwhile, as are 'when' and 'where', but I think that a fuller explanation of 'why' would be far more enlightening. And then, as noted to me earlier, there is always the possibility of answering the inquiry with, "We don't know yet." Sometimes with, "We don't know if we ever will." But it seems that, "We're still curious as to what it is that causes this to occur and provide a fuller explanation of why it occurs as it does," is a more appropriate approach than denying all usefulness of asking 'why'.

That is the Socratic Method, one question leads to another and another and finally truth. Problem solving in a group for me was Socratic, but most would not call it that.

The problem is when someone simply asks why over and over ignoring relies.

Socrates was said to be a real pain in the ass, at least twosome. He used 'why' as a weapon.

 

[whollygoats]

Does David Tong qualify as an acceptable source to the arbiters of this board?

 

[excreationist]

skepticalbip:

I found a good video about why the speed of light exists - it is from PBS Space Time, like that video about information travelling backwards in time.

https://www.sciencealert.com/watch-why-the-speed-of-light-is-not-about-light
Why The Speed of Light Is NOT About Light
More like speed of causality.

10m24s "the finite speed of causality is fundamental to us having a universe in the first place"

 

[skepticalbip]

skepticalbip:

I found a good video about why the speed of light exists - it is from PBS Space Time, like that video about information travelling backwards in time.

https://www.sciencealert.com/watch-why-the-speed-of-light-is-not-about-light
Why The Speed of Light Is NOT About Light
More like speed of causality.

10m24s "the finite speed of causality is fundamental to us having a universe in the first place"

I gotta ask, did you actually follow and understand that video or just grab onto the statement about the speed of causality? It is difficult to imagine that you could not have seen the statement in the OP video that we don't have a theory for light as pure bull shit if you have the background tool box to be able to follow this video.

Yes, c is the speed of causality which makes it the speed of light in any reference frame. I haven't found the videos in that series to be helpful to those who don't already pretty much understand what is being presented - except maybe giving them a "wow" of being awed by a flood of information that they they didn't and still don't understand.

 

[excreationist]

skepticalbip:

I found a good video about why the speed of light exists - it is from PBS Space Time, like that video about information travelling backwards in time.

https://www.sciencealert.com/watch-why-the-speed-of-light-is-not-about-light
Why The Speed of Light Is NOT About Light
More like speed of causality.

10m24s "the finite speed of causality is fundamental to us having a universe in the first place"

I gotta ask, did you actually follow and understand that video or just grab onto the statement about the speed of causality? It is difficult to imagine that you could not have seen the statement in the OP video that we don't have a theory for light as pure bull shit if you have the background tool box to be able to follow this video.

Yes, c is the speed of causality which makes it the speed of light in any reference frame. I haven't found the videos in that series to be helpful to those who don't already pretty much understand what is being presented - except maybe giving them a "wow" of being awed by a flood of information that they they didn't and still don't understand.

I followed a lot of the video - but I didn't know what they meant by the Lorentz transformation. I can look into that in the future.

 

[excreationist]

....I haven't found the videos in that series to be helpful to those who don't already pretty much understand what is being presented - except maybe giving them a "wow" of being awed by a flood of information that they they didn't and still don't understand.

I'm finding them enlightening. I'm glad I've come across them. I think as I watch more of them, things will fall into place more.

I'm currently watching:
The Nature of Nothing
https://www.youtube.com/watch?v=X5rAGfjPSWE

This video talks about:
Quantum Field Theory
https://www.youtube.com/watch?v=ATcrrzJFtBY

Feynman Diagrams
https://www.youtube.com/watch?v=fG52mXN-uWI

They have dozens of other videos.

 

[skepticalbip]

....I haven't found the videos in that series to be helpful to those who don't already pretty much understand what is being presented - except maybe giving them a "wow" of being awed by a flood of information that they they didn't and still don't understand.

I'm finding them enlightening. I'm glad I've come across them. I think as I watch more of them, things will fall into place more.

I'm currently watching:
The Nature of Nothing
https://www.youtube.com/watch?v=X5rAGfjPSWE

This video talks about:
Quantum Field Theory
https://www.youtube.com/watch?v=ATcrrzJFtBY

Feynman Diagrams
https://www.youtube.com/watch?v=fG52mXN-uWI

They have dozens of other videos.

That is good. It is nice to hear that you are enjoying them. But I still question if you really actually understand them. For instance, the first that you linked about the speed of causality explained why the speed of causality or light is what it is (that was sorta the whole point of the video)... can you explain in your own words how that speed must be precisely what it is since you have watched and enjoyed the video?

Enjoying a video and actually understanding it are very different things, though not necessarily mutually exclusive.

 

[excreationist]

That is good. It is nice to hear that you are enjoying them. But I still question if you really actually understand them.

I think I'm gaining an understanding in quantum physics though I often don't completely understand them.

For instance, the first that you linked about the speed of causality explained why the speed of causality or light is what it is (that was sorta the whole point of the video)... can you explain in your own words how that speed must be precisely what it is since you have watched and enjoyed the video?

I don't have any idea about why the speed of light must be precisely what it is. The reason why I was interested in them saying that it is about a speed of casuality was because that would have applications in the simuation idea - in order to limit how much computational power is needed.

Enjoying a video and actually understanding it are very different things, though not necessarily mutually exclusive.

Hopefully I'll continue to enjoy those videos and watch those videos about Quantum Field Theory and Feynman Diagrams. I probably wouldn't understand the math but I'd have a better idea about what those things mean.