The Galaxy Insight: 'The Universe is in Some Deep Sense Tied to Homo Sapiens'

[JimC]

"we are only aware of one species that is conscious in the way we are, and that is our own species".

What about dogs, horses, parrots, and gorillas? (hi, Koko)

 

[Ursa major]

Are dogs, horses, parrots, and gorillas conscious in the way we are?

 

[Brian G Turner]

This thread is really beginning to lose its course - let's bring in back around to quantum physics, please.

 

[Astro Pen]

I'll meet you at Pantheism
Spinoza is unavailable but I'm sure he would contribute to the thread if he were around

ps As a newby If I am sailing too close to the religion ban I won't be offended by this being removed.

 

[RJM Corbet]

As most people may have only skimmed this and as the link was further back in the thread, here is a pull-out from one of the articles posted by @Extollager (post #22) in which John Wheeler suggests a macrocosmic demonstration of the two-slit experiment – in effect suggesting that the past of the universe is affected by our observations of the universe as it is now.

Does the Universe Exist if We're Not Looking?

"Wheeler's hunch is that the universe is built like an enormous feedback loop, a loop in which we contribute to the ongoing creation of not just the present and the future but the past as well. To illustrate his idea, he devised what he calls his "delayed-choice experiment," which adds a startling, cosmic variation to a cornerstone of quantum physics: the classic two-slit experiment ...

Wheeler has come up with a cosmic-scale version of this (two slit) experiment that has even weirder implications. Where the classic experiment demonstrates that physicists' observations determine the behaviour of a photon in the present, Wheeler's version shows that our observations in the present can affect how a photon behaved in the past.

To demonstrate, he sketches a diagram on a scrap of paper. Imagine, he says, a quasar — a very luminous and very remote young galaxy. Now imagine that there are two other large galaxies between Earth and the quasar. The gravity from massive objects like galaxies can bend light, just as conventional glass lenses do. In Wheeler's experiment the two huge galaxies substitute for the pair of slits; the quasar is the light source. Just as in the two-slit experiment, light — photons — from the quasar can follow two different paths, past one galaxy or the other

Suppose that on Earth, some astronomers decide to observe the quasars. In this case a telescope plays the role of the photon detector in the two-slit experiment. If the astronomers point a telescope in the direction of one of the two intervening galaxies, they will see photons from the quasar that were deflected by that galaxy; they would get the same result by looking at the other galaxy. But the astronomers could also mimic the second part of the two-slit experiment. By carefully arranging mirrors, they could make photons arriving from the routes around both galaxies strike a piece of photographic film simultaneously. Alternating light and dark bands would appear on the film, identical to the pattern found when photons passed through the two slits.

Here's the odd part. The quasar could be very distant from Earth, with light so faint that its photons hit the piece of film only one at a time. But the results of the experiment wouldn't change. The striped pattern would still show up, meaning that a lone photon not observed by the telescope travelled both paths toward Earth, even if those paths were separated by many light-years. And that's not all.

By the time the astronomers decide which measurement to make — whether to pin down the photon to one definite route or to have it follow both paths simultaneously — the photon could have already journeyed for billions of years, long before life appeared on Earth. The measurements made now, says Wheeler, determine the photon's past. In one case the astronomers create a past in which a photon took both possible routes from the quasar to Earth. Alternatively, they retroactively force the photon onto one straight trail toward their detector, even though the photon began its jaunt long before any detectors existed.

It would be tempting to dismiss Wheeler's thought experiment as a curious idea, except for one thing: It has been demonstrated in a laboratory …

Wheeler conjectures we are part of a universe that is a work in progress; we are tiny patches of the universe looking at itself — and building itself. It's not only the future that is still undetermined but the past as well. And by peering back into time, even all the way back to the Big Bang, our present observations select one out of many possible quantum histories for the universe ..."

edited

 

[Venusian Broon]

As most people may have only skimmed this and as the link was further back in the thread, here is a pull-out from one of the articles posted by @Extollager (post #22) in which John Wheeler suggests a macrocosmic demonstration of the two-slit experiment – in effect suggesting the effect is also evident on a cosmic scale and so not limited to sub-atomic quantum level:

Does the Universe Exist if We're Not Looking?

“Wheeler has come up with a cosmic-scale version of this (two slit) experiment that has even weirder implications. Where the classic experiment demonstrates that physicists' observations determine the behaviour of a photon in the present, Wheeler's version shows that our observations in the present can affect how a photon behaved in the past.

To demonstrate, he sketches a diagram on a scrap of paper. Imagine, he says, a quasar — a very luminous and very remote young galaxy. Now imagine that there are two other large galaxies between Earth and the quasar. The gravity from massive objects like galaxies can bend light, just as conventional glass lenses do. In Wheeler's experiment the two huge galaxies substitute for the pair of slits; the quasar is the light source. Just as in the two-slit experiment, light — photons — from the quasar can follow two different paths, past one galaxy or the other

Suppose that on Earth, some astronomers decide to observe the quasars. In this case a telescope plays the role of the photon detector in the two-slit experiment. If the astronomers point a telescope in the direction of one of the two intervening galaxies, they will see photons from the quasar that were deflected by that galaxy; they would get the same result by looking at the other galaxy. But the astronomers could also mimic the second part of the two-slit experiment. By carefully arranging mirrors, they could make photons arriving from the routes around both galaxies strike a piece of photographic film simultaneously. Alternating light and dark bands would appear on the film, identical to the pattern found when photons passed through the two slits.

Here's the odd part. The quasar could be very distant from Earth, with light so faint that its photons hit the piece of film only one at a time. But the results of the experiment wouldn't change. The striped pattern would still show up, meaning that a lone photon not observed by the telescope travelled both paths toward Earth, even if those paths were separated by many light-years. And that's not all.

By the time the astronomers decide which measurement to make — whether to pin down the photon to one definite route or to have it follow both paths simultaneously — the photon could have already journeyed for billions of years, long before life appeared on Earth. The measurements made now, says Wheeler, determine the photon's past. In one case the astronomers create a past in which a photon took both possible routes from the quasar to Earth. Alternatively, they retroactively force the photon onto one straight trail toward their detector, even though the photon began its jaunt long before any detectors existed.

It would be tempting to dismiss Wheeler's thought experiment as a curious idea, except for one thing: It has been demonstrated in a laboratory …

This is just a nice example that we live in a Quantum universe (I'll assume that the experiment has been done, I haven't looked it up to check it's validity. Or know if there are doubts about the result, but let's leave that to one side.)

So it appears, from experimentation that the two slits can be a metre away or a billion light years away and as long as the photons we are trying to measure are coherent before the measurement is made* - we get the same results. Which shows that Quantum theory remains valid, which is a good thing. It would be eye-popping if it weren't the case. The Quasar example is extreme, but what it shows is that even if we did the experiment with slits at one metre, when we make a measurement, decoherence caused by measurement, makes the quantum effects vanish. Which we interpret, as limited beings of space and time, as somehow changing something in the past.

I don't see this as a paradox or issue - just that we are chronically underequipped as humans to actually make any sense of the quantum world of the very small. Our experience is of a 'macro Newtonian classical' world instead.

It is a problem with regards to Einsteins misgivings about this instantaneous 'movement' that occurs at the moment of measurement (which is greater than the speed of light)...but both General Relativity and Quantum theory are clearly incomplete theories that need to be overhauled to make a better theory of the universe. That is not a contentious statement - I am sure all physcists agree with this.

The important thing is that we don't need 'consciouness'** in modern Quantum theory to cause this.

I'm pretty sure Wheeler was talking about this sort of thing in the 1960s - at least I remember reading about this in the mid 1980s, so this isn't a new idea.

------------------------------------------
* I refer you to view the Sabine video "Is Covid there if nobody looks?" posted above that discusses decoherence and the measurement problem.

** Frankly we don't have a good definiton of what this actually is, which probably needs a thread of its own...but I don't think we'd get very far

 

[Astro Pen]

My own theory is that what we experience as the "now" is the point of quantum probability resolution. The future has multiple possibilities, and may be mutable in terms of will. But the now is the point where the probability collapses as the 'targets', in all their forms, are hit and the probability wave disappears, leaving only the single locked outcome called 'the past'.
Past and future are qualitatively different in that regard.
Whether we confuse free will with simply 'not knowing outcomes' is one for the philosophers.
The moving finger of probability writes, and having writ moves on.

 

[RJM Corbet]

This is just a nice example that we live in a Quantum universe (I'll assume that the experiment has been done, I haven't looked it up to check it's validity. Or know if there are doubts about the result, but let's leave that to one side.)

So it appears, from experimentation that the two slits can be a metre away or a billion light years away and as long as the photons we are trying to measure are coherent before the measurement is made* - we get the same results. Which shows that Quantum theory remains valid, which is a good thing. It would be eye-popping if it weren't the case. The Quasar example is extreme, but what it shows is that even if we did the experiment with slits at one metre, when we make a measurement, decoherence caused by measurement, makes the quantum effects vanish. Which we interpret, as limited beings of space and time, as somehow changing something in the past.

I don't see this as a paradox or issue - just that we are chronically underequipped as humans to actually make any sense of the quantum world of the very small. Our experience is of a 'macro Newtonian classical' world instead.

It is a problem with regards to Einsteins misgivings about this instantaneous 'movement' that occurs at the moment of measurement (which is greater than the speed of light)...but both General Relativity and Quantum theory are clearly incomplete theories that need to be overhauled to make a better theory of the universe. That is not a contentious statement - I am sure all physcists agree with this.

The important thing is that we don't need 'consciouness'** in modern Quantum theory to cause this.

I'm pretty sure Wheeler was talking about this sort of thing in the 1960s - at least I remember reading about this in the mid 1980s, so this isn't a new idea.

------------------------------------------
* I refer you to view the Sabine video "Is Covid there if nobody looks?" posted above that discusses decoherence and the measurement problem.

** Frankly we don't have a good definiton of what this actually is, which probably needs a thread of its own...but I don't think we'd get very far

Thanks VB. Yes I did watch the two videos you posted.

Yes the observer doesn't have to be human, or even conscious. Also the distance doesn't affect the two-slit experiment because it is still measuring sub-atomic photons, regardless of the distance they have travelled.

But the time-lag adds in the past/present entanglement complication?

And in practice the observer in the case is human? It is a human measuring the arrival of the photon?

But ... it quickly spirals away over my head. It gets weird. Wheeler's physics is obviously way out of my league. Even the simplified stuff.

 

[Ori Vandewalle]

As far as Wheeler's quasar thing, the experiment as described hasn't really been done. To get interference effects between two galaxies, you'd need to be looking at light with wavelengths on the order of that distance; ELF is an understatement. But the tabletop version--which has been performed--gets called the delayed choice quantum eraser. Here's a critical look at the interpretation of that experiment from a Many Worlds guy, physicist Sean Carroll.

The Notorious Delayed-Choice Quantum Eraser – Sean Carroll

www.preposterousuniverse.com

An important bit:

“But interference only happens when the traveling electron goes through both slits, and the smooth distribution happens when it goes through only one slit. That decision — go through both slits, or just through one — happens long before we measure the recording electrons! So obviously, our choice to measure them horizontally rather than vertically had to send a signal backward in time to tell the traveling electrons to go through both slits rather than just one!”

After a short, befuddled pause, the class erupts with objections. Decisions? Backwards in time? What are we talking about? The electron doesn’t make a choice to travel through one slit or the other. Its wave function (and that of whatever it’s entangled with) evolves according to the Schrödinger equation, just like always. The electron doesn’t make choices, it unambiguously goes through both slits, but it becomes entangled along the way. By measuring the recording photons along different directions, we can pick out different parts of that entangled wave function, some of which exhibit interference and others do not. Nothing really went backwards in time. It’s kind of a cool result, but it’s not like we’re building a frickin’ time machine here.

Basically, these experiments don't actually "erase" any information about the wavefunction. All that happens is the information gets entangled with various parts of the experimental setup, such that they're not available to you (and the detector).

 

[RJM Corbet]

But the tabletop version--which has been performed--gets called the delayed choice quantum eraser

Oh, so that's the principle of the delayed choice quantum eraser. Thank you.

Sean Carrol and the philosophy of physics.

 

[Extollager]

Are dogs, horses, parrots, and gorillas conscious in the way we are?

I don't think they are. A simple way of suggesting why goes like this: Man is the animal, the only animal so far as we know, that makes promises.

In order to make promises you have to have three capacities, all working together.

1.You have to have a sense of personal identity: because I know that I am I, I can make a promise on my own behalf.
2.You have to have a sense of the future, a time that does not exist for us, but will.
3.You have to have a language that can express the above. (I can't imagine how one would make a promise or a vow, even inwardly to oneself, without language.)

So far as I am aware, there's no evidence that these animals -- elephants might be added to the list -- possess those capacities.

Now how these capacities of human beings might relate to quantum entanglement might or might not be germane to the present discussion.

 

[RJM Corbet]

The delayed choice quantum eraser experiment:

 

[RJM Corbet]

 

[Ursa major]

The delayed choice quantum eraser experiment:

Speaking from utter and complete ignorance of even the basics of wave functions (amongst many other aspects of this and other matters scientific) -- not that I have to tell you this, given what I'm about to say -- I was wondering about the scope of the wave function in the experiment.

Could the wave function not include (at minimum) all of the experimental equipment as well as the subject of the experiment, rather than just the particle(s) being experimented upon? If so, why would information need to be passed backwards in time? Wouldn't the observed result of the experiment be the result of the collapse of this wider wave function?

Or, to put it another way, are we not perhaps getting an odd (i.e. counter-intuitive) result because we are mistaking what is no more than a part of an isolated quantum system for an isolated quantum system?


(In case you're wondering, I've purchased both a bullet-proof vest and a big bucket of popcorn, so I should be prepared for whatever reaction my question elicits, so feel free to let rip if you want to.)

 

[Ori Vandewalle]

Indeed, there is but one wave function (from a certain point of view). With very careful setup, we can isolate small chunks of it. But only temporarily.

Less mysteriously, from the perspective of quantum field theory, all of space is permeated by various fields (the electron field, the quark field, the Higgs field, etc.). These fields vibrate with particular modes (adding up to a total wave function), and if some small patch of a field gets excited, we call that excitation a particle.

 

[RJM Corbet]

Speaking from utter and complete ignorance of even the basics of wave functions (amongst many other aspects of this and other matters scientific) -- not that I have to tell you this, given what I'm about to say -- I was wondering about the scope of the wave function in the experiment.

Could the wave function not include (at minimum) all of the experimental equipment as well as the subject of the experiment, rather than just the particle(s) being experimented upon? If so, why would information need to be passed backwards in time? Wouldn't the observed result of the experiment be the result of the collapse of this wider wave function?

Or, to put it another way, are we not perhaps getting an odd (i.e. counter-intuitive) result because we are mistaking what is no more than a part of an isolated quantum system for an isolated quantum system?


(In case you're wondering, I've purchased both a bullet-proof vest and a big bucket of popcorn, so I should be prepared for whatever reaction my question elicits, so feel free to let rip if you want to.)

It's obviously not a simple discussion. Here is the full 90-minute Joe Rogan/Sean Carroll podcast. Of course it's not necessary to listen to the whole thing to continue the discussion.

Can an ant, even in principle, ever understand a cell phone? Can man ever, even in principle, understand the universe? The 'pop' media physicists seem to believe that the answer is yes. So perhaps that's the focus of the real debate?

 

[Ursa major]

Can man ever, even in principle, understand the universe?

The question you need to ask yourself -- that we need to ask ourselves before we claim to be special in the greater scheme of things -- is whether or not (and how) Homo sapiens is more than "a tiny cog that doesn’t really make much difference to the running of the huge machine", when the species in the the family Formicidae are (assumed) not to be?

 

[RJM Corbet]

The question you need to ask yourself -- that we need to ask ourselves before we claim to be special in the greater scheme of things -- is whether or not (and how) Homo sapiens is more than "a tiny cog that doesn’t really make much difference to the running of the huge machine", when the species in the the family Formicidae are (assumed) not to be?

Well your comment is not a response to the sentence from my post that you pulled out?

Newton and Einstein and others believed that they were just uncovering a small part of reality. There was that humility. The modern perception that science can understand everything -- even in principle -- that's the issue?

 

[Ori Vandewalle]

I'm not sure that's an accurate characterization of Einstein. He might not have said science can understand everything full stop, but he did believe the world was intrinsically knowable. There's a quote from him that goes, "Subtle is the Lord, but malicious He is not." Lord/He here are probably best understood as Nature, and what Einstein meant is that while the world may be hard to understand, it's not designed to be cruelly, hopelessly complicated.

 

[RJM Corbet]

I'm not sure that's an accurate characterization of Einstein. He might not have said science can understand everything full stop, but he did believe the world was intrinsically knowable. There's a quote from him that goes, "Subtle is the Lord, but malicious He is not." Lord/He here are probably best understood as Nature, and what Einstein meant is that while the world may be hard to understand, it's not designed to be cruelly, hopelessly complicated.

But at the same time we are saying that man is no different really than a wasp against a window pane? Which is it to be -- is man special enough to be able to understand the universe, or not?

Is the world 'designed' to be cruelly, hopelessly complicated? Does the dog care whether the flea on its back understands it or not?