Entangled particles used for communication

[andrew s]

@vlaiv not as I understand it. Firstly, if a system is in an eigen state it will remain in it as it evolves in time. If it is not it will evolve as per the time dependant Schrodinger equation. Both these assume no interaction with the environment. 

If you make a measurement on an otherwise isolated system you will always get an eigen state as the answer. If you remeasure it in the same way you get the same answer. If you don't know the state (say electrons from a heated fillament) your results will be truly random on the first measurement.  A measurement entangles, say the electron, with the instrument. 

You only get a non random result on remeasuring an eigen state again in the same way otherwise it is always random.

Decoherence is in effect a series of weak measurements on the system. It entangles the system with the environment and in so doing it removes any superposition and pushes the system into the classical states.  

You can do the double slit experiment with electrons in a vacuum and gradually raise the air pressure as you do the interference pattern weakens and finally goes with the classical trajectories taking over. 

Regards Andrew 

[vlaiv]

4 minutes ago, andrew s said:

Firstly, if a system is in an eigen state it will remain in it as it evolves in time.

Not sure if this is correct in general - it is only correct for stationary states - for example energy (conservation of energy), but if you measure position of electron (and thus "prepare it" at certain position) - evolution in time will spread its position all over the place.

As for the rest - again we agree in what you've said - but you don't address what I've asked.

Let me try again - this time with dual slit experiment. Imagine we have vacuum case - electrons are shot at screen and detected on screen. Let's examine individual "hit" of an electron. Just before hit - electron's wavefunction is such that it can be detected on any of the fringes - but it will be detected on just one. I'm saying - what if position on the screen depends on QM state of screen.

QM state of electron is the same so it can't be used to determine where it will land. We can now say:

1) either electron randomly interacts with screen at one particular place

2) electron deterministically interacts with screen at one particular place because that place was "the most suitable" for combined evolution of QM states of electron and screen.

QM state of electron is rather simple and can be described fairly easily. QM state of screen is so complex that there is no easy way to record it / know it. This complexity hides determinism in the process and place selection seems random - but it is not. It is decoherence of electron QM on complex state of screen that flows deterministically.

[andrew s]

Yes your right about energy eigen states. The remeasurement holds for discrete eigen states.

As to your question I better understand it now. I have never read any proposal to this effect. I would assume 1) from all I have read.

2) would require something like the  Block Universe where spacetime is a static 4d cube where we just experience dynamics. 

Bell's inequallity excudes any classical determinism of the kind you propose. 

Regards Andrew 

 

[Ouroboros]

7 hours ago, andrew s said:

Maybe our and their technology is not up to it yet. Strength of signal  and sensitivity of detectors. Regards Andrew 

Yes. Phenomenal amounts of power would be required to set up a radio beacon radiating in all directions for it to be detectable anywhere in the galaxy. As someone said - that’s not a radio beacon. That’s a weapon! 

[Paul M]

28 minutes ago, Ouroboros said:

That’s a weapon! 

The first episode of Coronation St. is only 5 years away from Aldebaran.

Let's hope it falls on deaf ears. Aldebrians might mistake it as an act of war...

[JamesF]

2 minutes ago, Paul M said:

The first episode of Coronation St. is only 5 years away from Aldebaran.

Let's hope it falls on deaf ears. Aldebrians might mistake it as an act of war...

Or possibly the final throes of suicide...

James

[Corncrake]

14 hours ago, Tiny Clanger said:

* I'm carefully stepping around religion here ... philosophy is quite bad enough ...

Oh dear ! now look wot u done !  aint we all, and the trouble with philosophy is everyone has their own opinion.

As someone who remembers Drake publishing his equation,
 and has been a practitoner of Maxwell's dark arts to earn a crust (else I might have been a theorist !) for about as long,

s/n ratio, time sphere, broadcast/narrowcast, coherent emission, timedivision/arc multiplex, noisiest place to do it ie.Hydrogen21cm !, whatever,  all pales into insignificance. It all reduces down to do you want to be heard ? I suggest we should not. But we could if we wanted to with our current technology, within the limits of Einstein communicatability.

I like the theory ( brought  to us by B. Cox recently )  that we are not special, it just takes this long for the universe to spawn such creatures as us, we may be alone, but there will be more along soon !

Anyone know the latest on that variable star that is/was thought to be vanishing within a Dyson sphere ? It has all gone quiet ! ?

 

Edited March 28, 2021 by Corncrake

[saac]

13 hours ago, Paul M said:

The first episode of Coronation St. is only 5 years away from Aldebaran.

 

The poor sods they have years of watching ahead of them  - mercy, 

Jim 

[Corncrake]

13 hours ago, Paul M said:

Aldebrians might mistake it as an act of war...

No, I think not, they will sigh sadly and say "The poor saps, 405 lines and no colour, is that the best they can do ? "

They dont realise the great leap forward into the future that is coming their way, yes a whole 625 of them .

[Ouroboros]

Isn’t the problem with instantaneous communication that it allows messages to be sent into the past?  Something that’s likely to cause all sorts o problems. 

[saac]

15 hours ago, Paul M said:

Let's hope it falls on deaf ears. Aldebrians might mistake it as an act of war...

 Well if they don't they certainly will when Easter Enders arrives a few year later

 

Hey just a thought,  could our extraneous radio and TV signals  be considered electromagnetic pollution . Humans what are we like . 

[Tiny Clanger]

39 minutes ago, saac said:

Hey just a thought,  could our extraneous radio and TV signals  be considered electromagnetic pollution . Humans what are we like . 

Reminds me  of this https://en.wikipedia.org/wiki/United_States_National_Radio_Quiet_Zone

Ironically I heard a radio program about it ...

[Paul M]

39 minutes ago, saac said:

when Easter Enders arrives

No further evidence required to show what a thoroughly unpleasant species we are! 

[Michael Kieth Adams]

Thanks again.   This has been a whole lot of fun.   We keep trying to believe that we are “Normal”. When we apparently are not.  We live on second or third generation planets which are apparently quite rare.  Maybe that’s why there is no one to talk to yet.    Maybe the key to faster than light communication just hasn’t occurred to anybody here yet.   Who knows, maybe Earth cats are the Galactic experts in experimental gravity.  I love cats but I sort of doubt that they are.    We think, therefore we screw up.  Again, thank all of you.  You have taught me a lot.

[Gfamily]

On 27/03/2021 at 21:29, Paul M said:

The first episode of Coronation St. is only 5 years away from Aldebaran.

Around 2nd week of May 2025. It might make a useful quiz question some time.  

 

(Maybe something about a Rover ('s Return) arriving at another star system.)

Edited March 29, 2021 by Gfamily

[Corncrake]

On 30/03/2021 at 00:22, Gfamily said:

(Maybe something about a Rover ('s Return) arriving at another star system.)

I'll pretend not to know what you mean !

Ena Sharples would send any alien home in fright

 

Edited April 2, 2021 by Corncrake

[Corncrake]

On 29/03/2021 at 21:36, Michael Kieth Adams said:

which are apparently quite rare.  Maybe that’s why there is no one to talk to yet. 

**

On 28/03/2021 at 05:52, Corncrake said:

I like the theory ( brought  to us by B. Cox recently )  that we are not special, it just takes this long for the universe to spawn such creatures as us, we may be alone, but there will be more along soon !

** Watch up, already done that bit !

[ollypenrice]

The problem with anthropomorphism is that it is highly insidious. It creeps into our thinking and infects it without our noticing. Implicit throughout the thread are several entirely anthropomorphic assumptions.: All intelligence leads to technology. All intelligence produces 'civilizations.' All intelligence is composed of many individual beings with a need and a desire to communicate between themselves and with others. 

It's possible that our anthropomorphic assumptions are valid because of some cosmic evolutionary principle as yet not known, but it is equally possible that our version of intelligence is atypical.

Olly

PS

 

[Paul M]

I've always been of the opinion that it would be better for alien life to find us on their terms, let them have the upper hand. Because as sure as eggs is eggs, we'd destroy them eventually given the chance.

I really hope there are sentient aquatic beings in the sub surface oceans of Ganymede and I hope we never find them.

[andrew s]

1 hour ago, ollypenrice said:

The problem with anthropomorphism is that it is highly insidious. It creeps into our thinking and infects it without our noticing. Implicit throughout the thread are several entirely anthropomorphic assumptions.: All intelligence leads to technology. All intelligence produces 'civilizations.' All intelligence is composed of many individual beings with a need and a desire to communicate between themselves and with others. 

It's possible that our anthropomorphic assumptions are valid because of some cosmic evolutionary principle as yet not known, but it is equally possible that our version of intelligence is atypical.

Olly

Very interesting as always @ollypenrice. What our singular example has shown is that our evolution of "thinking ability" and the development of "technology" has enabled us to out compete those species that don't have these abilities.

Evolution is blind to good or bad as shown by the first oxygenators killing  off all the organisms that exploited the reducing atmosphere but could not adapt to it becoming oxidising.

How extraterrestrial organisms evolve will depend on what evolutionary pressure they are presented with.

For good or ill we are what we have evolved to be.

Regards Andrew 

[vlaiv]

19 minutes ago, andrew s said:

For good or ill we are what we have evolved to be.

Also, good and bad are inherently terms that we defined because we evolved to the point of developing sense of ethics and morality.

[Macavity]

2 hours ago, Paul M said:

I've always been of the opinion that it would be better for alien life to find us on their terms, let them have the upper hand. Because as sure as eggs is eggs, we'd destroy them eventually given the chance. I really hope there are sentient aquatic beings in the sub surface oceans of Ganymede and I hope we never find them.

The boot could be on the other foot? lol. Re. anthropomorphisation:  In the late 60's, child-friendly (back then, me!) articles considered methods of communicating with aliens!?! Arrange SMELLY (Suphur based lifeforms?) Onions like well-known constellations? (It was acknowledged Aliens might be from "much further away" though!). Stephen Wolfram speculated that we may not even be able to even *recognise* aliens - If we restrict them to being "like" us. Others say "they" may already be (or have been!) here? Maybe not quite the (contemporary) "VIRUS in my PC", but the general idea rather resonates with me? 🤔

If contacted, "Keep Schtum"!?! Who wants to end up a Zoo Specimen (if indeed that)? 🙃

Edited April 2, 2021 by Macavity

[ollypenrice]

2 hours ago, andrew s said:

Very interesting as always @ollypenrice. What our singular example has shown is that our evolution of "thinking ability" and the development of "technology" has enabled us to out compete those species that don't have these abilities.

Evolution is blind to good or bad as shown by the first oxygenators killing  off all the organisms that exploited the reducing atmosphere but could not adapt to it becoming oxidising.

How extraterrestrial organisms evolve will depend on what evolutionary pressure they are presented with.

For good or ill we are what we have evolved to be.

Regards Andrew 

One defining characteristic of terrestrial life is predation. It vastly increases (and affects the nature of) competition between species. I wonder if there might be alien ecosystems without predation? It would be nice if there were. I have this notion for a short story in which passing alien spacecraft fire off the odd missile at the predatory Earth in the way that 18th century navigators would blast off the odd disapproving cannonball in the direction of cannibal islands...

Olly

[vlaiv]

1 minute ago, ollypenrice said:

One defining characteristic of terrestrial life is predation. It vastly increases (and affects the nature of) competition between species. I wonder if there might be alien ecosystems without predation? It would be nice if there were. I have this notion for a short story in which passing alien spacecraft fire off the odd missile at the predatory Earth in the way that 18th century navigators would blast off the odd disapproving cannonball in the direction of cannibal islands...

Olly

Predation is again concept related to our terminology.

It is no different than consuming plants or inorganic material. We make distinction based on our understanding of life, but it describes very nature of life - gathering resources from surroundings that sustain life.

We would not say that cow is predator would we? But it also eats live things.

You could argue that it is not actively pursuing its pray but Wildebeest will travel many miles in order to reach grasslands - is that predation? 

As long as "predator" does not have idea of its "pray" as being living thing that needs to be hunted - what makes it predator?

[saac]

Duplicated post - sorry - editing got me tangled up   

Jim 

Edited April 2, 2021 by saac