Sean Carroll on Causation in physics

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Sean Carroll on Causation in physics

Postby hyksos on October 8th, 2016, 1:22 am 

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Re: Sean Carroll on Causation in physics

Postby Dave_Oblad on October 8th, 2016, 9:00 am 

Hi all,

I think I must disagree with this. Any effect, by definition is an Event. And Events can't be said to have happened unless there was a means of measuring it. All Events have a Cause.

The example of a number sequence was dumb. It destroyed what credibility was there for the sake of making a point that isn't even related to the concept. It doesn't matter what Scale we are talking about, including Quantum Scales. I want to see him name a single Effect that doesn't have a Cause. Any attempt to do so will demonstrate that a failure is likely due to not having enough information to see or measure the Cause.

I agree that Time doesn't exist in the conventional way we accept. In my book.. Time is actually a physical distance, just like X,Y, and Z. I have no problem with Quantum Causality having the ability to go backwards in Time and even return an Effect to the Present. But the question is: Does the Future already exist? In my opinion, it doesn't.

As for the flow of events towards the Future (Arrow of Time), that is a Macro Scale Cause/Effect stream directly related to the Expansion of Time, which is the Speed of Light. In other words, the Expansion of Time is one directional, like inflating a balloon where the Surface is the Present. But the inside of the Balloon is a Solid and allows bi-directional flow of some types of information.. Ie: Entanglement.

Flow of information via Electromagnetic Forces (Geometry) are restricted to the 3D Surface, hence it is one directional over that surface (the direction of expansion). But flow inside can be nearly instantaneous (if not actually instantaneous) because it's not restricted by the Expansion Process (the Creation of new Time).

I'm not certain I communicated that concept well enough.. but it doesn't matter. Folks will try to force my concept into their concept of Reality, and when it doesn't mesh, they will reject it anyway. That's cognitive dissonance.. lol.

We need to unlearn so much.. Oh well.

Regards,
Dave :^)
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Re: Sean Carroll on Causation in physics

Postby DragonFly on October 8th, 2016, 3:18 pm 

For our convenience, we often refer to the immediate 'cause' of an effect by placing a local, and thus artificial, boundary, cutting off all of the history before, so it's really more like that all that goes on is a continuation of the one big Effect of the Big Bang. The present keeps turning into the future, from its inputs, yes, but these inputs come from the inputs of the past 'nows', and so on.
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Re: Asking the Right Question?

Postby Faradave on October 9th, 2016, 2:55 pm 

I own two of Carroll's video courses (Time & Dark Matter/Dark Energy), which I've viewed several times. He's bright, thorough and methodical but a little rigid and monotonous. He makes a good case in answering the question, Why is time unidirectional (an arrow)?, essentially replacing this for macro systems, with, Why did the Big Bang start with such low entropy? I'm not sure that's progress but I learned a lot along the way. I ask instead, Why is space bidirectional? Unidirectionality could be the norm for dimensions, with "space" merely an emergent quirk.

Consider a narrow one-way street, starting right where you are. If it is rotated about that origin, a one-way field is generated. Any direction of travel is outward from the origin. Stopping after a distance, what are your options? The only rule is, you can't go back on a one-way street. So, a circumference at your radius, reveals that you can still proceed in any direction outward from the tangent to your location. That tangent is bidirectional! It offers freedom in two directions without violating the rule. This naturally emerges from a unidirectional field.

If the unidirectional radii are considered a temporal field, a circumference at any distance from the origin is a simultaneity, indicating the age of the field. That simultaneity defines a space, appearing bidirectional but in fact, as inaccessible as our own (lacking instantaneous travel). The tangent, represents a natural speed limit, necessarily resulting from radial unidirectionality and universal to every location on that space. It is also invariant, regardless of the outward path chosen.

Image
I modified Carroll's diagram of a temporal field (grey), by adding two circumferential arcs (blue) representing spatial simultaneities at times t1 & t2. I also added resting (dk. blue), lightlike (maroon) and disallowed (green) paths. The latter violates the one-way nature of dimensions, so lightlike is the speed limit.

Light Interval 2.jpg
Allowing for local flatness, a spatial arc is represented by its chord (ΔX), which provides the relation ΔX2 = ΔT2 + ΔI2. ΔI is the invariant component, corresponding to a lightlike spacetime interval. This rearranges to the familiar interval equation of SR, ΔI2 = ΔX2 - ΔT2. What a coincidence!

By rotating the one-way street in 4D, the unidirectional temporal field is enclosed at every radius (age) by a 3D spatial (bidirectional) surface, having the same tangent, universal, invariant speed limit (c) in every available direction.
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Re: Sean Carroll on Causation in physics

Postby DragonFly on October 9th, 2016, 4:12 pm 

Carroll's The Big Picture is new and great!
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Re: Sean Carroll on Causation in physics

Postby Dave_Oblad on October 10th, 2016, 3:32 am 

Thanks Faradave,

Nice graphics. We sing the same song and here are some other clues:

The Universe is more than just stretching, it growing by the addition of New Space-Time, emphasis on the Time. At the smallest Scales, Matter has no Inertia, no way to know what direction and velocity it is going. It can only be a progression of its history which demonstrates that Time has physical Thickness.. Ie: Your A=>B points.

If there is no Erase Function, then Time has physical thickness of the Space-Time Continuum all the way back to the beginning. Electromagnetic interactions are a 3D surface phenomenon. The Universe is expanding at the Speed of Light from your A=>B points and that Expansion (New Growth) is your One-Way Street (Arrow of Time). The Electromagnetic interactions can not go backwards in Time or they would destroy their History and thus Matter/Energy couldn't Exist with any progressive patterns.

The Speed of Light is invariant because that is the Speed of Expansion of New Space-Time. Your streets are being paved Forward (outwards) in Time at that specific Rate and you can't travel on the street until it exists or has been paved and prepared for you (initially blank). It needs to be blank or it would interfere with the progression of out-bound world-lines of everything we hold dear.

Electromagnetic information can not traverse the points marked A=>D, because they are Surface Geometries. World Lines outbound form a Spiral Pattern, like woven hair, away from the head (center). I believe you called this Chronaxial Spin. It is not just Microscopic. If you map the motion of the Planets around the moving Sun in the progression of Time, you still get Spirals as Chronaxial paths.

Because there is no Erase Function, there still exists a Quantum Continuum filling the area defined by the Blue dotted Circles in your Graphic. Quantum Information can take the path defined by A=>D. Or any path for that Matter except to exceed the Surface of "Now" away from the Center. This is the Expanding (active) Block Model.

Temporal DURATION only exists on the surface of "Now" because of the limited Growth Rate. Within the Quantum itself, you only require Sequence and Order for Causality. Duration can be eliminated allowing for Instantaneous transfer of Quantum Information between any two points inside the Total Volume, which is proven via Entanglement Experiments. I think you called them Spin-Holes, a Real path though a Quantum Continuum where Duration takes a back-seat or doesn't even exist.

The trick is to understand Bi-Directional Time without Duration. It's not easy, as it goes against all our natural instincts. I should also note that the historical Geometry of Matter/Energy restricts the growth of the SCALE of Newly grown Space-Time Continuum, otherwise Galaxies would be 3D expanding as fast as the Voids, which is NOT what we are observing. Voids grow faster than Galaxies.. they possess less Matter is the reason why.

Your description is nicely based on Math and mine is based on Logic and Observation. Both Models are derived independently but are too perfectly matched to just be a coincidence.

I don't think we see Eye to Eye on Black-Holes however (yet). Science has not yet accepted the concept that the Planck Unit has "Variable 3D Scale" based on its Neighbors and History. Once that aspect is understood, Black-Holes become rather Mundane with ordinary Physics going on. No infinities.. yippee.. lol. Just very slow and very massive Stars inside a Volume of greatly reduced Scale. Forced Local Scale is very important or Atoms wouldn't mesh properly to form Molecules etc.

Best wishes,
Dave :^)
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Re: Sean Carroll on Causation in physics

Postby hyksos on October 14th, 2016, 2:44 pm 

When Sean Carroll says that the equations and the physics of quantum mechanics do not respect or predict a difference between forward time and backward time, he is not opining. The equations literally do not contain this. You cannot 'pretend' they contain it -- they factually do not contain it. Your personal feelings don't matter against facts.

Following further in this direction -- an attempt was made to unify quantum mechanics with general relativity, in perhaps the most conservative way possible. The result is something called the Wheeler-DeWitt Equation. The crazy thing about this equation is that time 'cancels out'. There is no time in it. The equation's meaning suggests, in a way, that time does not exist.

No physicist denied the veracity of the Wheeler-DeWitt equation. But because it contained no time in it, they placed it on their shelves and tried to forget about it for several decades. Over those decades the equation was like a dirty secret everyone was trying to hide.

Notice that Carroll mentions the degree to which a small change will affect a large system later on in "time". I would ask you to remember what Feynman said during the Eselan lectures.



On its face, Feynman is telling the class here that the act of "measuring" a physical system is actually an act of making copies of quantum information in different places in spacetime.

Consider this process vis-a-vis what Sean Carroll says in this video about
"small disturbance" ---leads to---> "large consequence".
Caroll calls that an effect.

Carroll admits the reverse process is possible
"large consequence" ---leads to---> "small disturbance."
Caroll calls that a record.

A picture of this process begins to come into focus. We start to gain a glimpse into how being in a timeless universe, we 'experience' time flowing.

The rough synopsis of this goes like so: We are basically very smart animals who have a brain. The connectivity of our brains goes about quickly and naturally distributing quantum information to as many brain cells as possible. In this sense, the initial spacetime quantum event is a tiny effect at one spacetime point, and then a saturation of that event in informational copies at a "later" time in the spacetime, provided there is a brain between them.

The possessor of such a connected brain would "experience" himself having "memories" of a "past event". But at the quantum level -- base level of reality -- none of this is actually happening. What is actually happening is a region of spacetime in which an "earlier" section has one piece of quantum information, and a "later" time has a region which is saturated with that information. And this is a consistent "timeless pattern" because there happens to be a branching, highly-connected brain sitting between those two points.

So you are not "remembering" a thing that happened to you yesterday. What is actually happening is your brain is a tightly-woven network which had copied quantum information over and over again to different cells in your head via a tangle of axons and dendrites. Carroll's description of "time", as a small event leading to large macroscopic change, is what we have evolved to 'experience' as a direction of "time" moving "forward".

The philosophical leap-of-faith off the deep end goes like this: The 'act' of copying information did not happen, as if a verb that unfurls overtime. Merely that the physical appearance of a saturated quantum state will produce an observer who "feels" that "time has transpired", from his own perspective. At base physical reality, nothing transpired. The Wheeler-DeWitt equation is true.
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