Nope. That’s wrong.
Nope. That’s wrong.
You dont know this?
Granted, as a non-physicist I’ll have to look for the specific documentation (which I discovered many moons ago) but I’ll do my best.
Even if I cant find it, I know it to be true.
This was the famous experiment conducted ‘at a remove’ - I find it hard to believe that someone as qualified as yourself is unaware of this. (asking me to ‘prove’ its existence or cite a specific study is merely obfuscation on your part, but I will endeavour to source the original study but it has been a long time…Any Pinsters willing to help are most welcome to…)
in the meantime, can you cite any experiment which shows collapse without which-path, human apprehension?
Any one will do.
Any one at all.
You’re on the wrong forum pal. Check regular posts on Irish rental pressure pre and post CoVid spring, pretty charts etc
Forget about me. Did you actually read the quote I cited, or watch the video, in which that PBS Space Time presenter says there is no evidence that human consciousness is better at collapsing the wave function than an electronic detector? You do realise he’s a professor of physics at City University of New York?
Untwist yer panties there. I asked you for a link. How is that obfuscation?
So famous you can’t even remember enough details to Google it? Mmmkaayyy…
Listen, not all reputable scientists even agree that wave function collapse occurs, let alone that human consciousness is involved. You’ve got your wires crossed somewhere along the way. There is definitely no experiment that conclusively shows what you think it does. (I’ve no doubt you can find some fringe quack who thinks they have one).
Is the moon rotating more in the night sky these days than typical libration?
Been a while since I’ve visited the site and trying to find my way around it again but I spotted the local expert in this thread (Hi PS! )
Dubhgeannain, you definitely win question of the month (moon-related pun intended)! You have me really scratching my head here.
The short answer is no, the libration is actually less than normal. But I am far from an expert and you triggered me into two days of reading to try to understand the details. Until you asked, I’d never really considered the fact that the libration was variable.
I’m sure I am teaching granny to suck eggs here but, just to get the basics out of the way, there are at least four different causes of libration. The smallest one is physical libration. That’s due to the fact that the moon isn’t perfectly spherical. In the same way as the moon pulls on the Earth’s equatorial bulge causing the 26,000 year axial precession, the lumpiness of the Moon results in a small irregularity of rotation.
Then we’ve got latitudinal libration which is a nodding “yes” motion in the appearance of the Moon. That has two causes. One is that the Moon orbits at a five degree inclination to the ecliptic plane so we see a little “over” its north pole and “under” its south pole depending on the position above or below the ecliptic. (It’s also why we don’t get a solar and a lunar eclipse every single month). The second reason is that the Moon’s rotation axis is slightly tilted with respect to the orbital plane. Just as the Earth would be seen to be nodding annually from the Sun’s perspective due to tilting each hemisphere toward and away from the Sun, the Moon gives a similar nod on each orbit, adding to or subtracting from the first latitudinal libration.
Then there is the longitudinal libration which is the one we’ll be talking about as it’s the most pronounced. This one is fairly easy to explain in principle. The Moon is tidally locked to the Earth, which means its own rotation has been gradually slowed down by tidal friction until it rotates exactly once on each orbit of the Earth. If the orbit was perfectly circular there would be no longitudinal libration – we would see the same lunar meridian facing us all the time because the Moon would travel around its orbit by the same angle as it had rotated on its own axis:
But the orbit isn’t quite circular so the orbital speed varies, as does the orbital angle through which the Moon travels in a given time period. The rotational speed stays constant, with the nett result that we see the Moon twist to the easterly direction at one point in the orbit, and westerly at another.
All the librations add together, along with the varying lunar distance due to the elliptical orbit, to give us the familiar monthly libration and apparent change in size:
Actually, it doesn’t always have this head-rolling motion, like one of those bobblehead dashboard toys. The change of Moon position with respect to the ecliptic plane (and therefore latitudinal libration) goes in and out of sync with the monthly longitudinal libration ( – further reading here). The ascending and descending nodes – the points at which the Moon crosses the ecliptic – change position by a few degrees with respect to the orbit each month. Sometimes the librations look more like a diagonal “yes-and-no” nod. Here’s one of those times – note how the Moon seems to pivot around Mare Crisium, the dark patch at the top right:
We should finally mention in passing the diurnal libration. This is the effect such that between moonrise and moonset an observer at the equator will have been carried 8,000 miles around with the rotating surface of the Earth. They see the Moon from a different angle (by about 1 degree) due to parallax. However, we’ll stick to the so-called geocentric view for a hypothetical observer at the centre of the Earth.
Variation in the longitudinal libration.
Ok, with all that out of the way, why does the longitudinal libration vary from month to month? It hadn’t even occurred to me that it did. Then I dug out this NASA article and associated table giving hourly librations for the whole of 2020. The elon column is the lunar longitude of the sub-earth point. (See also Selenographic coordinates). This varies up to 8 degrees east or west of the lunar prime meridian due to longitudinal libration. When I bung it into Excel I get this beautiful graph:
I was suprised to see that the monthly amplitude of the longitudinal libration varies from around 10 degrees to almost sixteen! What’s more, it looks suspiciously like a half-annual cycle. Right now, in early July, it’s close to a minimum.
Given what we know about the origin of longitudinal libration, I immediately assumed that the change in libration amplitude must be due to a change in the eccentricity of the Moon’s orbit. More circular means less libration; more eccentric means more libration. And, indeed, when I add the lunar distance to the graph I see that this is indeed the case. (I’ve scaled it so that you can see libration and distance together – one unit on the orange trace represents 5000 km above or below the mean lunar distance of 384,400 km).
You can see that the apogee distances – the peaks on the orange trace – stay fairly constant, whereas the perigee distances – the orange troughs – vary quite a bit throughout the year. And we see that the lower amplitudes of distance and libration line up nicely, though a little out of phase. This is very much what we’d expect since these are the more nearly circular orbits.
A tentative explanation?
So now the question of why the longitudinal libration varies is simply replaced by why the distance between lunar apogee and perigee varies. I’ve read article after article, and none seem to gives a thorough explanation all in one place. Nevertheless, I can only conceive of one thing that would continuously alter the shape of the Moon’s orbit and that’s the Sun’s gravity.
I know that the Earth is closest to the Sun in early January and furthest in early July. However, from the graph above the smallest perigee distance doesn’t really line up with either of those dates. Then I thought maybe the tilt of the Earth’s axis with respect to the Sun-Earth line might be at play, due to some interplay between the Sun’s gravity and the Earth’s equatorial bulge pulling on the Moon. But the perigean minima don’t really line up with the solstices or equinoxes either. Finally I lost confidence that this was an annual variation at all, so I plotted the apogees and perigees for the next five years with the help of the Fourmilab calculator:
Once again I have plotted the lunar distance offset from the mean in units of 5000 km. The vertical grid lines mark the start of each year, while the minor ticks are lined up with the anomalistic lunar month – the interval between successive perigees. It’s quite obvious that the variation in perigee really doesn’t line up very closely with Earth’s year.
And so, back to the drawing board. How do we get the Sun’s gravity to alter the Moon’s orbit in a way that doesn’t primarily depend on the Earth-Moon system’s distance from the Sun? It’s both subtle and complicated, and it has to do with the way the Moon’s orbit is not in the ecliptic plane.
Just as the Moon alters the Earth’s tilt by pulling on the equatorial bulge, the Sun also causes the tilt of the Moon’s orbit to precess so that it rolls around like a dinner plate on its edge:
Unlike a dinner plate the Moon’s orbit is not circular, as we already knew. The Sun’s gravity also causes precession of the Moon’s line of apsis. (An apsis, plural apsides, is the collective term for an apogee or perigee so the line of apsis is the line connecting the two. Basically, it’s the long axis of the orbit). The apsidal precession seen from above the plane looks like this – I couldn’t find a totally appropriate picture so you’ll have to pretend this is the Earth and Moon rather than Sun and Earth:
Now we pretty much have the picture. When the Sun is pulling in the same direction as the line of apsis is pointing it will tend to increase the eccentricity of the Moon’s orbit. When it is pulling perpendicular to that line it will tend to circularise it. And that’s what causes the changes in the amplitude of longitudinal libration. The geometry of the Earth’s orbit means this is a roughly six-month cycle (called evection) but it is complicated by the precession of the Moon’s orbit. If we want to get really complicated, even the gravity of the other planets will have a tiny additional effect. It’s an amazingly intricate celestial dance.
Sources / further reading.
Wow - fabulous clear explanation… I’ve learnt the practicalities of using sextant/tables for ocean navigation, and lunar sightings have the most corrections for calculations (refraction, parallax etc!). Maskelyne spent his life trying to perfect a method of longitude navigation independent of time, by taking observations and then making predictions/developing almanacs for lunar distances etc. Wasn’t a totally off the wall idea, Jupiter’s moons had lent themselves to predictable almanacs, but accurate observations by sailors on deck were impractical! The moon was a lot harder to figure out - really interesting!
The sun-moon-earth - the three-body problem again?
Agreed, but many reputable scientists assert it does occur.
The experiment Im trying to describe/remember preceeded the DCQE photon path manipulation/obfuscation experiments and made do with erasing the which-path information in the manner described; deleting computer files of ‘measurements’.
Have been taking place for decades and their are multiple examples available.
But as you say yourself, if youre a physicist and dont know any of this then mmmmmmkaayyyy.
But hey,lets just end it all with your citation of the experiment which demonstrates weave collapse without which-path information or human apprehension of same.
Youve got 100 years of experiments to chose from so it shouldnt be too hard, right?
Great. Just paste one link to one of the “multiple available examples”. After all, you could hardly know about their multiplicity if you had no idea what they were. It’s been ten days since your previous post, plenty of time to find one link I would have thought. I would certainly look forward to reading about such a fascinating and sensational experiment. Did anyone try recovering the computer files by looking at magnetic hysteresis on the hard drive? Do you have to overwrite them with random bits, or is just throwing them in the trash can enough?
I never said I was a physicist and for the record: I am not a physicist.
I suspect you know that’s not how this works.
I’ve got thirteen billion years of experiments. The existence of helium from Big Bang and stellar nucleosynthesis is my evidence. The Gamow window results from the wave function of protons which can penetrate their mutual Coulomb barrier in a classically forbidden region to form deuterons. Is it your contention that 25% of the baryonic mass of the universe only came into existence when humans first looked at the stars? That would be kinda strange, given that helium burns to carbon and we couldn’t exist if the helium and further products of nucleosynthesis weren’t there first.
Now, my contention is that a deuteron nucleus has effectively “measured” the positions of the constituent protons so that they are not in some sort of weird superposition of fused and not fused. You can feel free to disagree all you want, although I’d consider it strange. But at the end of the day all I have consistently claimed on this thread is that scientists don’t know when wave function collapse happens, and that no experiment exists such as the one you are claiming (but, curiously, can’t find). I can point you at any number of scholarly articles to this end – try this one for size:
The author’s view is that quantum effects do not propagate to macroscopic laboratory scales (let alone to incorporate consciousness) “because the internal degrees of freedom and the surrounding environment, acting (among other effects) as a heat bath, ensures it behaves as a classical system”. Physics only makes sense when the physicist “abandons the untestable and implausible claim that the environmental heat bath can be described by an infinite-precision wave function that is subject to unitary time evolution”.
Although the particular views are the author’s own, he covers enough of the alternatives to show that there is not a scientific consensus. How do you think this squares with your alleged existence of multiple experiments over decades that conclusively prove the role of consciousness? Let’s face it: it can’t, and it doesn’t.
I cant remember the link I read, it was 20 years ago. You seem to be having the same trouble yourself -
I know thats not how it works when you are asked, but its fine when you ask me, right?
Of which about 12.998 billion years are unobserved by humans…
Thats so far from what I’m saying youre only a step away from crowbarring ‘How do they get the figs in the Fig Rolls?’ into the thread…
The DCQE experiment and its precursor (which I cannot find) prove that ‘measurement’ equates to which-path information. That information is independent of time and spacial contstraints.
It is this information that remains in an indeterminate state until an agency ‘knows’ it.
That agency is (thus far) limited to human apprehension or ‘knowing’ - likely what we call consciousness.
This consciousness function which operates in humans, has therefore, a universal (non-local, atemporal) character. Is this what frightens you?
If not thank you for presenting unimpeachable evidence which has solved what has, for over a century, evaded the finest human minds using the most advanced technologies in history.
There was me was expecting you to be an angry ranting person who’d follow my posts on other threads looking for things to contradict.
So, if you’ll go away and stop bothering me; Mods you can close the thread now- I accept that PS200306 has solved the universe.
(Post edited for civility)
Here’s an article that shows your consciousness-causes-collapse idea is not accepted by scientists generally.
Thank you for the civil response.
I have 3 points -
I contend that many people - including yourself - have failed to realise that QM/DCQE has unveiled a New Science.
The nature of this science is not one I fully comprehend.
I know that it is not the Old Science.
I also know that it neither invalidates or negates the old science.
Its just New.
My background is signals. I know that a signal is encoded on a wave and transmitted.
Nothing between the transmitter and receiver (modulator/demodulator) can decode the signal.
So, for example, standing between your radio and radio station does not allow you to hear the news.
in addition only when the signal is received can it be turned to sound.
Thats is to say it is not ‘sound’ until it is received.
It has the ability to be sound, it contains the characteristics required - if circumstances are met - to produce sound, but it is not in itself sound.
The radio - properly tuned - ‘collapses’ the signal and produces sound.
I hope this gives you an insight into what and why I think as I do.
Just because one can formulate a question does not in itself lend legitimise the question.
I can ask questions like ‘Where is red?’ ‘How big is Tuesday?’ , ‘How many kilograms in anger?’, ‘What colour are metres?’
Clearly these are nonsensical and we all understand this.
But they are not nonsensical as questions.
They are, on the surface, valid; one could imagine a child asking something similar.
A child would ask these questions not because it doesnt understand the question, but because it doesnt understand the object of the question.
More precisely, because it tries to force its current comprehension onto the object of the question.
Its tries to ‘fit’ the object into its current knowledge.
In doing so it reveals its lack of understanding.
We’ve all experienced children doing this, I imagine.
My point is that just because you can structure or direct a question - no matter how precise or detailed within the framework of our current understanding - does not mean that an answer is possible.
In summary, my position is that we are machines for turning information into knowledge and experience.
The source of the information or the purpose of the experience is beyond me.
QM – agree. It is shocking. DCQE – disagree. It contains nothing we didn’t already know.
Correct. That is the Correspondence Principle.
Nope, it confuses the sheeeitt out of me. Your radio does nothing of the sort. Sorry for having to correct you but I am not just being pedantic. Borrowing terms from different areas of physics and using them elsewhere by analogy is what I see all over youtube comments on physics videos. People think they can just concoct some word salad and it becomes a new theory of physics (that only they can understand, usually). Radio’s don’t collapse signals (or even ‘collapse’ them, with scare quotes). The radio as an invention predates the quantum revolution and can be understand entirely through classical physics. Or maybe your radio is just another analogy for what you believe consciousness does for the measurement problem. In which case, for god sake stop with the analogies. It’s word salad. Collapsing the wave function means an extremely specific thing in quantum physics. It means the wave function ceases to evolve unitarily and and collapses to a single eigenvalue corresponding to a measured observable. That’s a completely different kind of physics to anything that went before.
Interesting theory (and unfalsifiable since it involves teleology, therefore not scientific). I’m losing the thread here. Nothing in any of your three points is anything to do with collapsing any wave function in the quantum physical sense, let alone furthering your contention that consciousness is needed to do it.
I think I’m going to leave it here. My last response (before I edited it down to a single point) was a long rant, and I don’t wish to rant. I think anyone who wants to investigate the matter without bias for themselves can easily find out that current science completely disagrees with your unsupported assertion about consciousness and QM.
Maybe we could get back to what I think this thread was intended to be about – the corruption of science and academia by “new ways of knowing”. Here’s a vid in which students at Portland State University talk about their experiences of “social justice”. It’s long, but see for instance the guy at 11:50 who is studying maths education. In a class on how to teach kids about laying out a playground with geometric shapes, they are encouraged to talk about where they would fit the gender neutral bathrooms.
Social justice, critical race theory (“white privilege”), intersectional feminism, queer theory … all of them have emerged out of the remnants of postmodernism which had reached its nadir in the 1980s after the successes of western liberalism in the preceding decades. Another long vid, and somewhat academic, but well worth a listen as Helen Pluckrose does an amazing job of explaining how we got to where we are:
As the West goes wholesale into producing SJW’s and ideologues the East goes wholesale into producing engineers and entrepreneurs. Interesting times ahead.
If things are wobbling more than usual, have you checked that it’s not down to libation, rather than libration?
OK, I know, coat, door…
One for the road.
Apropos the quantum measurement problem, I think this recent experiment rules out the “consciousness needed” hypothesis. That wasn’t the point of the experiment, which was to show that a quantum superposition can be collapsed progressively. They put a system into a superposition of two pairs of states. By probing one pair they collapsed that part of the superposition, while still leaving a superposition of the other pair of states. Full pdf is available from here:
A summary is available here:
Here’s an extract in which I’ve highlighted the important bit (for our purposes) concerning the (unnecessary) role of the observer:
In the latest work, Markus Hennrich and colleagues at Stockholm University, Sweden, together with researchers at the universities of Siegen in Germany and Seville in Spain, performed an ideal measurement involving a single ion of strontium. As they report in Physical Review Letters , they began by using a laser to place the ion in a superposition of two states (out of a possible three), with each state corresponding to a different energy level of the ion’s outermost electron. They then used a short pulse from another laser to excite the ion from only one of the three states, causing it to fluoresce – an ideal measurement according to Lüders’ criteria.
In this measurement, a single photon is emitted in a random direction, making it difficult to detect directly. Instead, Hennrich and colleagues carried out what is known as process tomography. This involves using laser pulses that reveal, for every possible combination of superposition states, whether the superposition has been destroyed or preserved.
Repeating this process many times over, the researchers found that the excitation and emission destroyed all the superpositions related to the state being probed. The other superpositions, however, remained intact. According to Hennrich, this shows that he and his colleagues had indeed carried out an ideal measurement. What’s more, the fact that they did not need to detect the emitted photons shows that the measurement process does not depend on the presence of an observer. “It is already happening as a result of one fluorescence photon being emitted into the environment,” he says.
If thats what you think the thread is about then we are totally in agreement.
We are in agreement to the extent that I dont even engage with it.
This is what a social or civilizational - as opposed to individual - mental breakdown looks like.
This, by the way is by design; the current social/psychological order/norms prevents some new (likely commercial) enterprise from succeeding so it must be overcome.
For example, the BLM trope is designed to make any questioning of racism anethma to white populations.
The reason for this is demographics; Europe is in decline, Africa is extremely fertile.
In the next 10-20 years we will see a massive, unprecedented rise in immigration from Africa.
The BLM movement is designed to counter opposition to that.
So , yes, ts science Jim, but not as we know it.