Author Topic: Quantumn woo and immortality  (Read 595 times)

Offline trdsf

Re: Quantumn woo and immortality
« Reply #15 on: August 26, 2020, 10:45:20 PM »
I'll have a whack at a couple of these.

1) Quantum superposition.  I heard it like this, a photon "knows" when it's being watched, and will change its state depending on whether it's observed.

My understanding is that our methods of observation inherently cause minor disturbances in what's being observed - like using flash photography.  Photons aren't being sneaky or anything.  Matter isn't actually in multiple configurations at once - it's just that we can't observe them with much precision, so we consider it "blurry" until we get a nice, close look.
That's actually two different things here: the idea of a particle "knowing" it's being watched is called the 'observer effect', that the observation of a phenomenon changes the phenomenon -- makes the particle go through the right-hand or left-hand slit, makes the photon be polarized vertically or horizontally, that sort of thing.  It should be stressed that 'observer' does not mean 'sentient observer' -- an automated system causes the same effect.

The second part of this is the measurement problem that underlies the Heisenberg Uncertainty Principle.  We can't get a nice close look because there's a physical limit to how precisely we can measure a particles position and vector.  In order to measure where a particle is, we bounce a photon off it.  On the subatomic scale, even a fairly lethargic infrared photon is a collision of some moment, throwing the observed particle off in another direction.  To be able to determine its position more precisely, we have to use a higher frequency photon, which is necessarily going to hit the particle even harder and send it off in an even more hard to predict direction.  There's a similar trade-off if we try to measure its momentum, we lose certainty as to its position.  There is an inherent 'blurriness' at the quantum level that there isn't a way around.


2) Many Worlds interpretation.  Are there actually multiple universes where things unfold differently?  They brought up Schrodinger's Cat but I'm pretty sure that that whole thought experiment was intended to throw shade on Many Worlds - there's no box where a cat's possibly alive and possibly dead, it's either one or the other.
The Many Worlds interpretation is an interpretation of Quantum Mechanics that tries to deal with the philosophical messiness implied by the more standard Copenhagen Interpretation.  Copenhagen states that physical systems do not have definite properties until they are measured -- not just that we don't know what they are, but that they are actually not defined at all.  Many Worlds says that the states are defined, and when we observe it, we are shunted off into a universe where that is the quantum state and the other states hive off into the universes where the system was in those states.

Personally, I prefer the Instrumentalist Interpretation favored by Dirac and Feynman, best described as "shut up and calculate".


3) Can quantum entanglement lead to FTL communications or travel?
That... is the $64,000 question, and the answer is a definite "Who knows?"

Here's the setup: you have a device that emits two particles, and because of the nature of particle pair production, they must have opposite spin.  We won't get into spin other than to say it's a quantum property, something that is intrinsic to the particle and can be measured.  A mile away, your detector measures the spin of one particle and that instantaneously determines the spin of the other -- literally instantaneously, not limited to the speed of light.

The problem is, the generation of the direction of spin is itself a random quantum process -- it can't be encoded into it, and so quantum entanglement, so far as we currently understand it, cannot be used to transmit information at faster than the speed of light.

4) Black holes aren't really holes, are they?  You can't throw an apple down one and it appear in some other universe, right?  My understanding is the "hole" part isn't literally true, just a handy metaphor - stuff goes down, basically nothing* comes back out.  But it's more like an extremely compressed star that warps space to such a degree that basically nothing* can escape once it gets close enough - it's less like a hole and more like a pit that no one can climb out of.

(* except hawking radiation)
'Black hole' is a bad word.  The Russian term translates as 'frozen star', which is poetic at least.  I prefer 'hypermass', which is sometimes used in the UK, although by and large 'black hole' has become the generally accepted term.  'A pit you can't climb out of' is a pretty good definition, actually.

In a certain way of looking at it, they can be considered holes in spacetime, and 2D drawings of them often show them as a sort of curved hole in the 'surface' of spacetime -- but that's the problem of trying to reduce a 4-dimensional object down to a 2-dimensional drawing.

However, it's more than just a compressed star -- white dwarfs and neutron stars are compressed stars, but a black hole's gravity is so intense that the matter itself is squeezed out of existence, leaving only its gravity behind.  Even Hawking radiation isn't really matter escaping a black hole.  There is no escape from a black hole, and there's really not any matter in there anyway.  What Hawking radiation is, is virtual pairs of particles spontaneously forming and re-annihilating just outside the event horizon.  If one falls in, the other particle no longer has a pair to annihilate with, and the 'energy debt' required to promote it from being a virtual particle to a real one is paid out of the gravitational and spin energy of the black hole itself.  It might fall in too, but it also might escape to a large distance and appear to have been emitted by the black hole.


5) Is our universe predictable from the onset - a person with full knowledge about it could correctly predict how it's going to look a billion years from now (a clockwork universe)?  Or does the fuzzy nature of quantum physics allow it to go down unexpected roads to unforeseeable outcomes?
Our current understanding is that we can only predict probabilities, not certainties.  For macro scale objects (too large to suffer significant quantum effects on a regular basis), you can still only statistically state what its future is, and probabilities that are nearly impossible over the course of a week may be nearly inevitable over the course of a million years.

Does that help any?
"My faith in the Constitution is whole, it is complete, it is total, and I am not going to sit here and be an idle spectator to the diminution, the subversion, the destruction of the Constitution." -- Barbara Jordan

Offline Hydra009

Re: Quantumn woo and immortality
« Reply #16 on: August 26, 2020, 11:07:22 PM »
Yes, that helps a lot.  Though I'm curious about black holes and "there's really not any matter in there anyway".  Where did all the matter go?   

My understanding is that they start out with the mass of an already pretty hefty star (relative to the sun) plus whatever gets stuck in its gravity well.  So, lots of mass.  After all, that's what's sustaining its massive gravity well, right?  Gravity is just a function of matter.

Over time, black hole evaporation chips away at its mass due to mass-energy equivalence and after a really long time (much longer than anyone would care to wait) they'll eventually dissipate somehow.
« Last Edit: August 26, 2020, 11:25:15 PM by Hydra009 »

Offline trdsf

Re: Quantumn woo and immortality
« Reply #17 on: August 27, 2020, 12:05:37 AM »
Yes, that helps a lot.  Though I'm curious about black holes and "there's not matter down there anyway".  Where did all the matter go?
It's crushed out of existence -- maybe.  A white dwarf is held up by electromagnetic repulsion: it can't get any smaller because the electron shells can't get any closer, and it will slowly cool and die.

A neutron star is stronger than the repulsive force and crushes the electrons into the protons making more neutrons and releasing electron neutrinos... and that is stopped by the Pauli Exclusion Principle, the fact that two identical particles cannot occupy the same space at the same time going the same direction.  As all neutrons are identical to other neutrons, that means that they're as close as they can get and gravity at that scale can't pull them any closer.

In a star with sufficient mass to become a black hole, even the Pauli Exclusion Principle isn't enough and the neutrons are squeezed together and, well, theories abound.  Some think they're literally squeezed out of existence, leaving nothing behind but their gravity.  Some think they form a degenerate quark soup with no definite particles therein.  Unfortunately, this all takes place behind the event horizon, so it's not something that there's much chance of observing.  The best astronomers can hope for is a flash of neutrinos just before final collapse, but that's likely to be hidden inside a supernova explosion -- not very much signal and a whole lotta noise.

My understanding is that they start out with the mass of an already pretty hefty star (relative to the sun) plus whatever gets stuck in its gravity well.  So, lots of mass.  After all, that's what's sustaining its massive gravity well, right?  Gravity is just a function of matter.

Over time, black hole evaporation chips away at its mass due to mass-energy equivalence and after a really long time (much longer than anyone would care to wait) they'll eventually dissipate somehow.
There's some reason to think that a sufficiently strong gravitational field is (Hawking radiation aside) self-sustaining -- to the extent that since energy and matter are interchangeable, the incredible energy of the field operates in place of regular matter.  But... theoretical, not demonstrated.

Anyway, the terminal mass is not really that much bigger than the sun -- the Chandrasekhar limit, the maximum mass a star can have and still be a stable white dwarf, is only 1.4 times the mass of our sun.  Larger than that and it must collapse further to become a neutron star.

At 2.14 solar masses, we run into the Tolman-Oppenheimer-Volkoff limit (yes, that Oppenheimer), above which a (non-spinning) neutron star must collapse further.  Spinning ones can be more massive -- the most massive known neutron star is 2.74 solar masses, which is coincidentally also the mass of the least massive known black hole.

Hawking mentioned in A Brief History of Time a calculation by John Wheeler that if we made a hydrogen bomb using all the deuterium in the world's oceans, the pressure at the center would be sufficiently high to create a small black hole.  The lower limit on black holes is actually about 22 micrograms -- any smaller than that and it would need to be compressed to a size smaller than the Planck radius.  And the 22 microgram black hole would evaporate in 5x10-39 seconds anyway... not really long enough to get your grant paperwork filled out.
"My faith in the Constitution is whole, it is complete, it is total, and I am not going to sit here and be an idle spectator to the diminution, the subversion, the destruction of the Constitution." -- Barbara Jordan

Offline Baruch

Re: Quantumn woo and immortality
« Reply #18 on: August 27, 2020, 12:30:27 AM »
Yes, that helps a lot.  Though I'm curious about black holes and "there's really not any matter in there anyway".  Where did all the matter go?   

My understanding is that they start out with the mass of an already pretty hefty star (relative to the sun) plus whatever gets stuck in its gravity well.  So, lots of mass.  After all, that's what's sustaining its massive gravity well, right?  Gravity is just a function of matter.

Over time, black hole evaporation chips away at its mass due to mass-energy equivalence and after a really long time (much longer than anyone would care to wait) they'll eventually dissipate somehow.

Inside a Black Hole before matter is crushed out of 3d (not out of existence, the mass is still there even in the singularity) matter however distressed is as it was.  It simply can't easily get back out again (because that means reversing time) except thru Hawking radiation.  But the controversy is, mass is all that is left, no other state data is preserved, information is irreversibly lost.  It isn't as if a sofa goes in and comes out as a sofa again, just the mass of it, and randomly as radiation, not all at once.
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Offline Hydra009

Re: Quantumn woo and immortality
« Reply #19 on: August 27, 2020, 12:57:07 AM »
In a star with sufficient mass to become a black hole, even the Pauli Exclusion Principle isn't enough and the neutrons are squeezed together and, well, theories abound.  Some think they're literally squeezed out of existence, leaving nothing behind but their gravity.  Some think they form a degenerate quark soup with no definite particles therein.  Unfortunately, this all takes place behind the event horizon, so it's not something that there's much chance of observing.
My money is on the degenerate quark soup thingie.  This huge mound of ultradense stuff.  Stuff that we have no idea about because it could never exist outside of an event horizon.

Point is, I think the "hole" in black hole is a bit of a misnomer - it's not empty and it doesn't act as a tunnel to anything (hence the pit analogy).  At least, I don't think so.
« Last Edit: October 24, 2020, 09:26:06 PM by Hydra009 »

Offline Baruch

Re: Quantumn woo and immortality
« Reply #20 on: August 27, 2020, 01:13:41 AM »
My money is on the generate quark soup thingie.  This huge mound of ultradense stuff.  Stuff that we have no idea about because it could never exist outside of an event horizon.

Point is, I think the "hole" in black hole is a bit of a misnomer - it's not empty and it doesn't act as a tunnel to anything (hence the pit analogy).  At least, I don't think so.

White Holes are allowed, but would be very narrow, you can't slip thru one.
Ha’át’íísh baa naniná?
Azee’ ła’ish nanídį́į́h?
Táadoo ánít’iní.
What are you doing?
Are you taking any medications?
Don't do that.

Offline trdsf

Re: Quantumn woo and immortality
« Reply #21 on: August 27, 2020, 01:27:00 AM »
My money is on the generate quark soup thingie.  This huge mound of ultradense stuff.  Stuff that we have no idea about because it could never exist outside of an event horizon.

Point is, I think the "hole" in black hole is a bit of a misnomer - it's not empty and it doesn't act as a tunnel to anything (hence the pit analogy).  At least, I don't think so.
I prefer the 'crushed out of existence' theory myself, but given the complete lack of hard data either way, it's for purely aesthetic reasons.

It's theoretically possible for a black hole (I agree, it's not a good name) to be a gateway either between distant parts of the same universe, or between universes.  In a Schwarzschild black hole, it's not rotating and if you fall in, you can't avoid the singularity, and squish.

A Kerr black hole on the other hand is rotating and therefore has a ring singularity rather than a point, and it's speculated that passing through the center of the ring might act as a wormhole, or a gateway to another universe.  Unfortunately it's also speculated that they might be very finely balanced, and a distortion (say, an astronaut passing through the center of the ring) might unbalance the system, and squish.
"My faith in the Constitution is whole, it is complete, it is total, and I am not going to sit here and be an idle spectator to the diminution, the subversion, the destruction of the Constitution." -- Barbara Jordan

Offline SGOS

Re: Quantumn woo and immortality
« Reply #22 on: August 27, 2020, 06:52:12 AM »
Observing a black hole destroys the observer.

Offline Baruch

Re: Quantumn woo and immortality
« Reply #23 on: August 27, 2020, 08:48:17 AM »
Observing a black hole destroys the observer.

We can hope.  Worth a Darwin award for anyone who watched the Disney movie.
Ha’át’íísh baa naniná?
Azee’ ła’ish nanídį́į́h?
Táadoo ánít’iní.
What are you doing?
Are you taking any medications?
Don't do that.

Offline Baruch

Re: Quantumn woo and immortality
« Reply #24 on: October 24, 2020, 08:34:46 PM »
There is marketing in Western science, which when combined with public funds make its own version of Lysenkoism.  This is by an actual Dark Matter theoretician, talking about her own specialty.  This is science in the "Physics Of Star Trek" category.

Ha’át’íísh baa naniná?
Azee’ ła’ish nanídį́į́h?
Táadoo ánít’iní.
What are you doing?
Are you taking any medications?
Don't do that.