Quantum Field Theory: The Woo Stops Here

[PixyMisa]

You keep shifting the goalposts.

Not even once.

The claim is that if something interacts (in this specific case, neurons), then it is detectable by conventional particle physics experiments.

I have never claimed any such thing. The point is that people are trying to do an end run around the laws by asserting that something might exist that does not interact. Something that does not interact, by definition, does not exist.

Edit: Ah, I see where you're coming from. You're conflating two completely separate points.

First, we have, as Sean Carroll explains, definitive evidence that there are no new laws of physics that both act at everyday scales and are strong enough to account for any form of woo.

Second, we have the definition that something that does not interact does not exist. As I've said several times before, a system containing particle X which does not interact is identical to a system not containing particle X. So a particle that does not interact is a particle that does not exist, and the hypotheticals raised in this thread that do not interact likewise do not exist.

 

[PixyMisa]

Believers in such woo with agency believe they see a difference (Miracles!, answered prayer, ghosts, etc.).

Yes. They're wrong.

The premise is not that such woo action would be indistinguishable (as indicated above), just that it would be purposeful, unpredictable (from our perpspective), and disinterested in influencing experiments.

It doesn't matter what the premise is; it is a fact that if the woo action changes the world, we can detect the change as a difference from our predictions.

I agree with your 'indistinguishable' statements 100%. However, such seem less about QFT and more other arguments?

Sure. Remember, the point of the thread is that QFT stops the special pleading that there might be a new law of physics that allows for someone's favoured form of woo, not that QFT alone rules out every woo belief.

There are lots of ways for us to rule out woo beliefs; QFT is just one particularly effective method.

 

[PixyMisa]

Can you stop saying "by definition" as a smokescreen to hide the fact you have not provided an argument?

I have shown repeatedly in this thread that this is how precisely how we define existence, and why.

So, can you stop making strawmen?

 

[fuelair]

Well, Jabba is a Christian, and like all believers he thinks that there is a god who is above physics. Once you accept a magic theory like that, anything is possible, and no argument from physics will be really convincing.

The theory that a horde of tiny invisible magic imps are actually running the physics of the world could fit reality just as well as QFT, and it allows for all sorts of paranormal events, including the fact that the effects disappear under scientific scrutiny. It is only Occam's Razor that prevents us from accepting such a theory, but the Jabbas of this world do not have a razor of that kind.

Though they have quite enough of them to cut off their noses to spite their faces. Which is fine with me. Not that there is anything wrong with that!!!

 

[Soapy Sam]

Not even once.

1)... a system containing particle X which does not interact is identical to a system not containing particle X.
2) So a particle that does not interact is a particle that does not exist, and the hypotheticals raised in this thread that do not interact likewise do not exist.

I'm troubled by the "So". Are you deriving statement 2) from statement 1)?
If so, is that logically valid?
1+0=1
1-0=1
1X0=0
1/0=?

Here we have 4 interactions which might be considered to be non-interaction, yet they do not all have the same result.

The nature of arithmetical interactions is very limited. In physics, interactions may be far more subtle and complex.

For example, if an interaction had no detectable consequence for (say) a million years, it would be impossible, by any sensible definition, to test a relevant hypothesis in the lab. Even looking for present day consequences of million year old events would be impossible unless we knew what events to look for and knew they had measurable consequences other than the one we are testing for. (Otherwise, we could not know the events ever occured).
If the only detectable consequence turned out to occur in the past , even stranger problems may be envisaged.

What I'm suggesting is that some events may have consequences which are real, but undetectable - not by definition, but as a result of the nature of reality.

ETA- Temporal separation is one obvious , if unlikely possibility, but spatial separation would do. If the creation of a virtual photon is accompanied by the creation of a leprechaun in a galaxy far, far away, how would we test for that? (Especially if said creature vanished again a billionth of a second later. Is the Hubble capable of resolving a virtual leprechaun at the edge of the universe, even in principle?

 

[PixyMisa]

I'm troubled by the "So". Are you deriving statement 2) from statement 1)?

Yes.

If so, is that logically valid?

Yes.

1+0=1
1-0=1
1X0=0
1/0=?

Here we have 4 interactions which might be considered to be non-interaction, yet they do not all have the same result.

Sure. That's fine.

The nature of arithmetical interactions is very limited. In physics, interactions may be far more subtle and complex.

In reality, that's true. But these hypotheticals are explicitly defined such that there are no interactions. That's why I'm pointing out that they aren't real.

It would be the equivalent in your arithmetic analogy of:

1 + X = 1
1 - X = 1
1 x X = 1
1 / X = 1

Of course, no such thing is possible in arithmetic. But no such thing is possible in physics, either.

 

[Soapy Sam]

Yes.


Yes.

Hmm. That looks a bit circular to me. Elliptical, at least.

In reality, that's true. But these hypotheticals are explicitly defined such that there are no interactions. That's why I'm pointing out that they aren't real.

Reality is good, but we're in the "Paranormal" sub forum, so permit me a further speculation...

I wasn't 100% serious , as you probably realised, about a million year delay in effects following causes, - or worse yet, causes following effects, but it occurs to me that our definitions of the arrow of time pretty much assume that macroscopic events follow their causal events instantaneously. That's what time is.

But at the quantum level, do we have a definite time delay D between Cause C and event E?

What if "the paranormal" simply is hysteresis - a delay between C and E ? No new particles, no new processes; just something apparently happening at some time T with no apparent cause, because the actual cause was somewhere else, some time earlier?

For that matter, could that explain apparently acausal stochastic quantum events of any sort? There really was a cause, but it was a while ago. Just like most politics, does quantum mechanics only make sense in the light of history?

 

[PixyMisa]

What if "the paranormal" simply is hysteresis - a delay between C and E ? No new particles, no new processes; just something apparently happening at some time T with no apparent cause, because the actual cause was somewhere else, some time earlier?

If the laws of physics worked that way, the computers we're using to communicate would not work. At all.

For that matter, could that explain apparently acausal stochastic quantum events of any sort? There really was a cause, but it was a while ago. Just like most politics, does quantum mechanics only make sense in the light of history?

That would contradict Bell's theorem, and we're pretty sure Bell's theorem is true.

Technically, what you are suggesting is known as a local hidden variable theory, and Bell's theorem says that no local hidden variable can account for the observed behaviour of subatomic particles - that quantum mechanics is necessarily either acausal or nonlocal.

 

[GraculusTheGreenBird]

Not even once.


I have never claimed any such thing. The point is that people are trying to do an end run around the laws by asserting that something might exist that does not interact. Something that does not interact, by definition, does not exist.

Edit: Ah, I see where you're coming from. You're conflating two completely separate points.

First, we have, as Sean Carroll explains, definitive evidence that there are no new laws of physics that both act at everyday scales and are strong enough to account for any form of woo.

Second, we have the definition that something that does not interact does not exist. As I've said several times before, a system containing particle X which does not interact is identical to a system not containing particle X. So a particle that does not interact is a particle that does not exist, and the hypotheticals raised in this thread that do not interact likewise do not exist.

NotEvenWrongWrote: Gravitons and virtual particles both exist, according to quantum field theory. They both affect reality, at our energy scales, according to quantum field theory. Yet, it is impossible to detect them, according to the experimental predictions of quantum field theory.

Can virtual particles and gravitons be detected, and if not, does that mean they don't exist?

 

[PixyMisa]

NotEvenWrongWrote: Gravitons and virtual particles both exist, according to quantum field theory. They both affect reality, at our energy scales, according to quantum field theory. Yet, it is impossible to detect them, according to the experimental predictions of quantum field theory.

Can virtual particles and gravitons be detected, and if not, does that mean they don't exist?

It is trivially easy to detect gravitons. Are you sitting down? There you go.

 

[GraculusTheGreenBird]

Come on, Pixy, that is not detection of gravitons, that is detecting the effects of gravity. Gravitons are hypothetical particles.

Which cannot be detected, at present, yet are purported to cause the effect of gravity. So do they exist or not? That goes to the heart of the matter.

For what its worth, I agree with you on almost everything, particularly the "If it has no detectable effect on this universe, then it may as well not exist", but I would add the caveat "For all intents and purposes" or "to the best of our current knowledge" specifically because of the oddities like gravitons.

 

[PixyMisa]

The hypotheticals being raised here don't just have no detectable effect, they have no interaction by definition. That means that they don't exist by definition.

It's true that the properties of gravitons are such that it is not possible in practice to detect an individual graviton - the energies are just too low, because the force is so weak (though it is possible to support the hypothesis by testing other predictions, like gravity waves).

But for precisely that reason we can exclude gravity or similarly weak forces as causes for woo effects because we'd be talking about a field source the size of a mountain range, which we would notice.

 

[JoeMorgue]

This entire discussion illustrates the inherent difference between looking at the evidence and forming a conclusion and wanting a conclusion and trying to backfill evidence after the fact to support it.

The entire "X could be there and here's special pleading after special pleading reason why you can't prove X isn't there therefore X is there" routine is the purest form of irrational thinking.

 

[Soapy Sam]

All the more reason to propose them here and now.

 

[Soapy Sam]

If the laws of physics worked that way, the computers we're using to communicate would not work. At all.

Why not? Computers don't use ghosts, they use electrons. We know how they behave, most of the time. Maybe they behave differently some of the time. Is there any reason why there cannot be a significant time delay between certain causal events and their results? If there is such a reason, then is the delay between any electromagnetic event and it's immediate result always the same? What is the length of that delay?

If we can't have new particles, and we want woo, then we must have existing particles behaving unusually. For the duration of this thread, I want woo.

That would contradict Bell's theorem, and we're pretty sure Bell's theorem is true.

Would it? That does not seem so evident to me. If the cause of an event happened far far away and long long ago, it's going to look pretty damn acausal.

(I was born 6 weeks after Einstein died. I have a small warm place in my heart for hidden variables)

Technically, what you are suggesting is known as a local hidden variable theory, and Bell's theorem says that no local hidden variable can account for the observed behaviour of subatomic particles - that quantum mechanics is necessarily either acausal or nonlocal.

ETA-I'm trying to suggest the sort of objection some believers might, but I can't truly compete with the sort of mind that says the Loch Ness Monster is a spiritual entity and the reason we can't find it on sonar is because at those times it's in a spirit realm, only to return to the material world when people stop looking.
(Although Voyager 1 being 4 billion light years away requires a certain leap of faith, too. I guess Caroll meant kilometres.)

 

[PixyMisa]

Why not? Computers don't use ghosts, they use electrons.

Right, and you can't have both.

Maybe they behave differently some of the time.

Then computers wouldn't work. A desktop PC CPU performs about 50 billion macro-ops per second, which equates to something like, hmm, half a quadrillion transistor switchings per second, each involving a relatively small number of electrons. And there's a billion such CPUs in the world. If electrons behaved differently even one time in a quintillion, they'd constitute the number one cause of computer failures worldwide. It wouldn't just be obvious, it would be a major topic of study for computer scientists, electrical engineers, and physicists everywhere.

Is there any reason why there cannot be a significant time delay between certain causal events and their results?

Yes. As I said, that's what's known in physics as a local hidden variable theory, and as such it violates Bell's theorem.

If we can't have new particles, and we want woo, then we must have existing particles behaving unusually.

Right. And that's impossible too.

Would it?

Yes, by definition. Where is the information of the interaction held during the lapse of time between cause and effect?

ETA-I'm trying to suggest the sort of objection some believers might, but I can't truly compete with the sort of mind that says the Loch Ness Monster is a spiritual entity and the reason we can't find it on sonar is because at those times it's in a spirit realm, only to return to the material world when people stop looking.

Yes, you're trying to find the minimal change to reality that would allow for some form of woo. But it turns out that any such change would have drastic and obvious effects everywhere.

(Although Voyager 1 being 4 billion light years away requires a certain leap of faith, too. I guess Caroll meant kilometres.)

Heh. I didn't notice that.

 

[JoeMorgue]

Yes, you're trying to find the minimal change to reality that would allow for some form of woo.

That is an absolutely beautiful turn of phrase that which I will be stealing for use the future.

 

[Soapy Sam]

Then computers wouldn't work. A desktop PC CPU performs about 50 billion macro-ops per second, which equates to something like, hmm, half a quadrillion transistor switchings per second, each involving a relatively small number of electrons. And there's a billion such CPUs in the world. If electrons behaved differently even one time in a quintillion, they'd constitute the number one cause of computer failures worldwide. It wouldn't just be obvious, it would be a major topic of study for computer scientists, electrical engineers, and physicists everywhere.

You mean Windows 8?

Yes, by definition. Where is the information of the interaction held during the lapse of time between cause and effect?

Same place it's held now, I suppose. There must be a time lapse, unless the cause and effect are simultaneous. Actually, I feel "information" is not a helpful concept in this context. It implies coding systems, rules, interpreting systems and so on.Whack a nail with a hammer and the nail doesn't need to be told to go down. It goes down because EM and gravity give it no choice.I merely wonder if there might exist conditions in which time gives it a choice about when.

Yes, you're trying to find the minimal change to reality that would allow for some form of woo. But it turns out that any such change would have drastic and obvious effects everywhere.

I have to admit that I find that a rather shocking statement, particularly the way Carroll pulls it out of the hat in the vid. It's far from obvious where he's going and then wham!
It takes getting used to, even for a lifelong atheist and non-woo like myself. I doubt it is going to be accepted readily by anyone emotionally invested the other way.

 

[tsig]

You mean Windows 8?


Same place it's held now, I suppose. There must be a time lapse, unless the cause and effect are simultaneous. Actually, I feel "information" is not a helpful concept in this context. It implies coding systems, rules, interpreting systems and so on.Whack a nail with a hammer and the nail doesn't need to be told to go down. It goes down because EM and gravity give it no choice.I merely wonder if there might exist conditions in which time gives it a choice about when.

I have to admit that I find that a rather shocking statement, particularly the way Carroll pulls it out of the hat in the vid. It's far from obvious where he's going and then wham!
It takes getting used to, even for a lifelong atheist and non-woo like myself. I doubt it is going to be accepted readily by anyone emotionally invested the other way.

Emotions can't change reality.

 

[Soapy Sam]

Emotions are part of reality. I'm not sure what you mean. Could you clarify?