[geordief (OP)]

If we observe 2 stars at a very great distance  and the light arriving from them only amounts to a very low number of pixels , are there any quantum effects involved  in the observation?

Let's say it a is binary system.

How many pixels would you need to form any kind of a judgement  as to position and relative moment between them?

Would quantum effects come into play if the amount of light reaching the receptor was small enough?

[evan_au]

Let's say it a is binary system.
If we observe 2 stars at a very great distance  and the light arriving from them only amounts to a very low number of pixels , are there any quantum effects involved  in the observation?

Let's take the star Algol as an example (an Arabic name meaning "the ghoul"; sometimes called the demon star)
- It is 90 light-years away, so the diameter of the star's image on your retina would be less than the wavelength of visible light.
- Every 2.86 days, the brightness visibly halves (violating assumptions at the time about the unchangeable nature of the heavens)
- This is due to eclipsing binary stars

I don't see too many quantum effects here (apart from the fusion powering the star)
- Although the image is very small on your retina, it is very large at its source
- The finite size of your iris means that the image will be blurred to a larger size
- Passing through the atmosphere blurs the image considerably
- It doesn't matter how small the image is on your retina. if you can measure the brightness, you don't need the resolution needed to separate the stars in a telescope.

https://en.wikipedia.org/wiki/Algol

[alancalverd]

Quantum effects were very important in film-based astronomy and radiology.

To form an image in a silver halide crystal, you need  at least two photons to arrive within a fairly short time. In "normal" photography this isn't a problem as you have zillions of photons arriving in a fraction of a second, so the film blackening is proportional to the number of photons hitting each grain. But at very low intensities or very short exposures, you get "reciprocity failure" where the effect of the first photon decays before the second one hits the grain,or the exposure is too short for the second one to arrive at all. The astronomer's trick was to "pre-fog" the photographic plate with a hint of visible light, thus reducing the theoretical detection threshold to a single photon. The radiographer's trick was to convert the few high-energy x-ray photons to lots of visible photons and capture those, and at very low doses with an efficient fluoroscopic converter, you could see "quantum mottle" where each incoming photon had generated an isolated spot on the film.

In theory you can detect a single visible photon with a cooled photomultiplier or semiconductor - the latter being more common with x-ray photons.

[Eternal Student]

Hi.
   I think many of your ( @geordief  )  questions have been reasonably answered by others already.  Here is just a quick reply to each.

1) If a Billion people Toss, someone might get Heads a hundred times in a row.
Sheer chance or Probability?

   I don't understand what you see as the difference between the words "chance" and "probability" as used in your sentence,  sorry.

2) While Coin is in air, is it Heads & Tails both at the Same time.
Superposition?

    If you treat the coin as a QM object then you could consider it as being in a superposition of states while in the air.    Most people wouldn't treat a real world coin as a QM object, it's a macrosocopic object.

3) Say the Coin is tumbling down Stairs(t1 t2 t3 t4 t5)
If i exist inside of Only t3, i see Heads, but Others existing inside t1245 can see anything at Random(headsORtails)
Simultaneity?

   Is this a metaphor for people who exist in different universes as described in the many worlds interpretation of QM?   If it was then yes,  they can see different results and they see them simultaneously.   The branched worlds were just the one world until branching occurred.  So whatever event or outcome lead to the branching, that should have happened when the same past applied to all the worlds created in that branching.   Since the different worlds should not influence one another after branching, it's a bit arbitrary to ask if their time co-ordinates or flow of time would continue to be synchronous afterwards.   However, the same laws of physics should apply in all branches.

What i am tryin to ask is, can/has the Wave Function ever predicted an Inaccurate result, or is it 100 % Correct every single time.
Uncertainty?

    For certain, physicists sometimes make inaccurate predictions.   Furthermore, Quantum Mechanics is almost certainly not the final or ultimate theory that models and explains everything corrrectly.
    There are many inherent problems with Quantum Mechanics.   Problems concerning measurement and wave function collapse have been discussed elsewhere.   Other problems include assuming a particle does have a mass - which you will need to do when constructing the Hamiltonian that appears in the Shrodinger wave equation.   QFT is one extension of (basic) Quantum Mechanics where "mass" doesn't have to be an inherent property of particles (it can be just an interaction from a field).   QM, even in the more developed form of QFT, still doesn't reproduce results consistent with all of General Relativity (GR).

5) Has it Ever happened that a Coin was tossed & it Disappeared into thin air & never landed.
(lol sorry)

   Maybe.  QM predicts some incredibly strange things.

If we observe 2 stars at a very great distance  and the light arriving from them only amounts to a very low number of pixels , are there any quantum effects involved  in the observation?

   I think most of us are interpreting  "low number of pixels" as indicating only a low number of photons were also received.
   Yes...   for a small number of microsopic objects like photons, all the usual quantum mechanical behaviours could or should apply.   However, they are stated as having been detected by the receptor.   So measurement has been made, the wave function has collapsed, the photon is definitely at the detector and should behave much as you expect an ordinary particle to behave.

How many pixels would you need to form any kind of a judgement  as to position and relative moment between them?

    This sounds very specific to the equipment being used and what was being attempted.   The light probably went through some imperfect lens before it was brought to focus on this light recpetor,  it almost certainly went through a lot of air in our atmosphere.   QM effects that may happen involving detection at a pixel aren't the most limiting effect.
    Lots of information already exists on the internet about telescope and detector resolution limits. The wave-like behaviour of light (inlcuding X-ray, radio or any wavelength) generally puts the main constraint on "angular resolving power" or resolution but there will also be particle-like behaviour and QM effects.  @alancalverd has already said quite a lot about this.

Best Wishes.

[alancalverd]

If we observe 2 stars at a very great distance  and the light arriving from them only amounts to a very low number of pixels

Don't confuse between photons (what the source emits) and pixels (how the receiver is constructed).
In a direct-conversion system any pixel can be activated in principle by a single photon. The art of receiver engineering involves optimising the ratio of Pixel width to Boundary width within the constraints of the manufacturing process. If P>B you will lose resolution because each pixel will respond to photons from a wider area than necessary, and if P<B you will lose sensitivity because some photons will hit the boundary rather than the pixel.

How many pixels would you need to form any kind of a judgement  as to position and relative moment between them?

Two. If we initially detect intensity I₁ at pixel A and 0 at A + 1, then subsequently detect I _A < I₁ and I _A+1 > 0, we can infer that the binary is rotating.

[Eternal Student]

Hi.

any pixel can be activated in principle by a single photon.

    I'm not an engineer and I honestly don't know what sort of detection devices exist so I went shopping on the internet.   Does "in principle"  mean  ?4, 000   (four thousand GBP) per pixel?

SPD.jpg (26.2 kB . 347x411 - viewed 521 times)

I also thought these SPD  (single photon detectors) were considerably less than 100% effective.   Sometimes only about 10% effective.   The one in this advert claimed 60% peak detection efficiency but there is a "dead time" of at least 50 ns after each detection during which the SPD will not click on impact with a photon. 

If we initially detect intensity I1 at pixel A and 0 at A + 1, then subsequently detect I A < I1 and I A+1 > 0, we can infer.......

    ..... that the pixels just don't click with 100% effectiveness?   that the air changed its density locally?   or maybe that the source image was rotating.

Best Wishes.

[Zer0]

Hi.
   I think many of your ( @geordief  )  questions have been reasonably answered by others already.  Here is just a quick reply to each.

i had Observed this before, in another Thread, you perhaps were referring to me, but you ended up typing Origin's nickname.
I thought it must be a typo or system error.
But here We are, it seems to have happened again.
Instead of my nickname, you typed Geordief's.
But i still Wish to confirm this, was this a typo, or is there a Glitch in the System?

Coz in another Thread, i had typed Varsigma's nickname expecting a response from them, but instead Neilep ended up responding.

Is This phenomenon taking place with Anybody Else?
(to clarify a bit, i type username @abcde...i see it as @abcde.
But the user @abcde sees it as @1234567.
& eventually user @1234567 ends up responding to me, on a query, which i had asked to user @abcde)

1) If a Billion people Toss, someone might get Heads a hundred times in a row.
Sheer chance or Probability?

   I don't understand what you see as the difference between the words "chance" and "probability" as used in your sentence,  sorry.

There is No difference.
Sorry i confused you.
Rephrase - if a billion people toss the Coin, one of em gets heads 10 times in a row.
This is simply Probability Right?
Not a Miracle!

2) While Coin is in air, is it Heads & Tails both at the Same time.
Superposition?

    If you treat the coin as a QM object then you could consider it as being in a superposition of states while in the air.    Most people wouldn't treat a real world coin as a QM object, it's a macrosocopic object.

Most people are Sane enough to Not do that.
Agreed!
((2) - got it)

3) Say the Coin is tumbling down Stairs(t1 t2 t3 t4 t5)
If i exist inside of Only t3, i see Heads, but Others existing inside t1245 can see anything at Random(headsORtails)
Simultaneity?

   Is this a metaphor for people who exist in different universes as described in the many worlds interpretation of QM?   If it was then yes,  they can see different results and they see them simultaneously.   The branched worlds were just the one world until branching occurred.  So whatever event or outcome lead to the branching, that should have happened when the same past applied to all the worlds created in that branching.   Since the different worlds should not influence one another after branching, it's a bit arbitrary to ask if their time co-ordinates or flow of time would continue to be synchronous afterwards.   However, the same laws of physics should apply in all branches.

& what if t12345 was Time, and i checked heads/tails 5 times.
Will i see a Pattern emerge?
t1h  t2t t3h t4t t5h
Or
t1t t2h t3t t4h t5t
Or
t1h t2h t3h t4h t5h
Or
t1t t2t t3t t4t t5t
Will i be able to Predict future readings of t6 t7 t8 t9 t10 based on emergent pattern or Do the Readings remain Absolutely Random without predictable Patterns?
(t/1/h --- time/1/heads
&
t/1/t --- time/1/tails)

What i am tryin to ask is, can/has the Wave Function ever predicted an Inaccurate result, or is it 100 % Correct every single time.
Uncertainty?

    For certain, physicists sometimes make inaccurate predictions.   Furthermore, Quantum Mechanics is almost certainly not the final or ultimate theory that models and explains everything corrrectly.
    There are many inherent problems with Quantum Mechanics.   Problems concerning measurement and wave function collapse have been discussed elsewhere.   Other problems include assuming a particle does have a mass - which you will need to do when constructing the Hamiltonian that appears in the Shrodinger wave equation.   QFT is one extension of (basic) Quantum Mechanics where "mass" doesn't have to be an inherent property of particles (it can be just an interaction from a field).   QM, even in the more developed form of QFT, still doesn't reproduce results consistent with all of General Relativity (GR).

Cordially agreed!
QM is Incomplete.
((4) - got it)

5) Has it Ever happened that a Coin was tossed & it Disappeared into thin air & never landed.
(lol sorry)

   Maybe.  QM predicts some incredibly strange things.

Strange things like Virtual Particles?
That pop into existence from nothing & go back into nothing.
If VPs are truly physical, Why then does the Universe not glow with a Blinding light when matter/antimatter VP pairs collide?

Or VPs just exist in 2d sheets of mathematical equations & the Energy released from anti/matter collisions remains trapped behind thick book covers, busy illuminating the bookmarker Within.


Best Wishes.
Much Appreciated & Thanks!

[evan_au]

I also thought these SPD  (single photon detectors) were considerably less than 100% effective

A cryogenically-cooled semiconductor sensor as used by astronomers has something like 70% photon-capture efficiency, at chip level.
- You have to treat any lens or window with anti-reflective coatings, or you lose another 10% of photons due to reflections at the air-glass-air boundary
- The mirrors on the telescope lose about 10% of the photons before they hit the detector (which is why they recoat the mirrors every year).
- More is lost due to the prime focus mirror, and its support structures

These semiconductor sensors have the advantage that they can form an image of a region of the sky, rather than recording the intensity at just one point
- One amazing observatory that should start operations in about a year has a 3 Gigapixel camera, formed from a matrix of semiconductor sensors.
https://en.wikipedia.org/wiki/Vera_C._Rubin_Observatory#Camera

The example you found appears to be a photomultiplier tube, which (in the past) tended to be a single pixel, ie not an image-forming device? (I am sure alancalverd will know!)
https://en.wikipedia.org/wiki/Photomultiplier_tube

Will i be able to Predict future readings of t6 t7 t8 t9 t10 based on emergent pattern

As far as we can tell, quantum phenomena are truly random.
- There are some interpretations of Quantum Theory that involve "hidden variables" - if you could peek at these, you may be able to predict the outcome - but peeking at these quantum variables changes their value
- It's a bit like peeking at the unseen Wave Function - it collapses

[Eternal Student]

Hi.

Instead of my nickname, you typed Geordief's.

   I.T. support would say it was a PEBKAC issue (problem exists between keyboard and chair).   
I'm going to claim the forum software didn't make it easy.    When the post gets long it splits replies into separate pages.  I could only see the name on the immediately preceeding post when I was writing the reply.   I can only apologise @Zer0.
   

[alancalverd]

Quote from: alancalverd on Today at 09:21:10
If we initially detect intensity I1 at pixel A and 0 at A + 1, then subsequently detect I A < I1 and I A+1 > 0, we can infer.......
    ..... that the pixels just don't click with 100% effectiveness?   that the air changed its density locally?   or maybe that the source image was rotating.

Detection efficiency isn't relevant - you have to integrate over a reasonable period to determine intensity.
Air density and turbulence may have been problems for neanderthal astronomers, but any respectable Waitrose customer buys his data from space telescopes nowadays.   

[alancalverd]

The example you found appears to be a photomultiplier tube, which (in the past) tended to be a single pixel, ie not an image-forming device? (I am sure alancalverd will know!)

Not really even a pixel, though we have used arrays of photomultipliers to determine the location of an event in a scintillator crystal or swimming pool full of carbon tetrachloride*, and display the resulting vector as a pixel on a flat screen.

*"micellar water" be damned! a million gallons of CCl₄ will really shift a layer of makeup. Wax on, wax off.

[evan_au]

Air density and turbulence may have been problems for neanderthal astronomers, but any respectable Waitrose customer buys his data from space telescopes nowadays.   

If you want high resolution images of really faint objects, the best option is still to use really large telescopes on top of really high mountains (a number of them in the Atacama desert of South America).
https://en.wikipedia.org/wiki/List_of_largest_optical_reflecting_telescopes

These telescopes use adaptive optics and high-powered computing to decode the atmospheric distortions in real time, and adjust the shape of a compensating mirror every millisecond or so to cancel the atmospheric distortion.
- This is most useful on telescopes of 8m diameter and above (a 40m diameter telescope is under construction in Chile, intended to be operational in 2028)
- I am assuming that the calculations involved treating light from the star as a classical light wave passing through a classical medium with time-varying refractive index, so no quantum effects need to be calculated.
https://en.wikipedia.org/wiki/Adaptive_optics#Wavefront_sensing_and_correction

[alancalverd]

- I am assuming that the calculations involved treating light from the star as a classical light wave passing through a classical medium with time-varying refractive index, so no quantum effects need to be calculated.

At some point in the system, you need to generate an electrical signal representative of the wavefront distortion. This involves a photon-electron converter (usually a CCD), which, like all photon detectors, employs quantum phenomena!

[varsigma]

There's this astronomical effect called the Hanbury Brown-Twiss effect. Something about interferometry from optically distant light sources that you could look at, that might be connected to the question.

It's both classical (it's observed at radio frequencies I.O.W), and quantum (it involves "photon bunching"),

[Zer0]

@Evan

Hmm...so no playing peek-a-boo! in the Quantum world.
 : /
booring!


@Eternal

haha@PEBKAC
But loong hours at the Table is not nice, wrist bones n elbows might ache.

Why don't you get one of those automatik massager chairs?
hehe@TickleTickle
: )
(sending Apology back to Sender as refused to be collected by the Recipient)


@Var
Thnx for your Valuable input.

https://en.m.wikipedia.org/wiki/Hanbury_Brown_and_Twiss_effect


ps - @G
i wish you'd speak your mind a bit more.
cya!