The Illusion of Free Will in the Context of Time Travel and Paradoxes

In summary, the conversation discusses the idea of time travel and the paradoxes that come with it. Some believe that it is not possible to travel back in time as it would create a paradox, while others argue that it may be possible if we select a history that does not cause a paradox. The theory of quantum physics also suggests that all possible histories exist until we collapse the wave, meaning that any paradox already exists as a possible history. The conversation also brings up the concept of the Grandfather Paradox, where killing one's grandfather before their father is conceived creates a paradox. Some propose the idea of the Grandfather's Revenge Theory, where the grandfather travels forward in time to kill their descendant before they have a chance to travel back in time
  • #71
Awww Dave, you hurt my feelings.
 
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  • #72
boffinwannabe said:
as for collapsing the wave, has it not been shown this is when information becomes known? The delayed quantum eraser experiment showing it wasnt the measurement that collapsed the wave, it was when the information became available to the observer. I take this to mean the moon is nothing more than a probability wave until someone observes it.

To my knowledge this is incorrect. The delayed quantum eraser only supports, in the view of a particular interpretation of QM, that a particle can "choose" its path based on the detection of its partner particle AFTER the original particle has already been detected. But I'm not a QM guru, so I don't know for sure.
 
  • #73
agentredlum said:
What do you mean what do i mean? The Bohr atom.

Per your previous post:

However, is it wise to accept quantum jumping AND electron clouds? If electrons are not permitted certain orbits then wouldn't that mean the probability of finding the electron at a non-permissable orbit should be zero? This doesn't look like a probability cloud or wavefunction or whatever you want to call it. t seems to me Q.M. supports both. Q. M. wants quantum jumps and continuous distribution of probability functions.

I don't follow you on this. What does quantum jumping and electron clouds have to do with the Bohr model or non-permissable orbits?
 
  • #74
Drakkith said:
Per your previous post:
I don't follow you on this. What does quantum jumping and electron clouds have to do with the Bohr model or non-permissable orbits?

perhaps this link will help, here is a portion of the link

The Bohr atom Niels Bohr (1852?1962) combined classical mechanics and some revolutionary postulates to formulate a model of the hydrogen atom that hoped to circumvent some of the difficulties of classical physics and still explain atomic spectra. The following are his basic postulates.
Postulate 1: The electron moves in only certain permitted circular orbits?quantized states?around the positive nucleus under the influence of the Coulomb force.
Postulate 2: The electron does not emit energy when it is in one of the allowed orbits called a stationary state.
Postulate 3: When the electron jumps from one permitted state to another, the energy is given off as a particular photon with energy equal to the difference in the energies of the initial and final states:

http://www.cliffsnotes.com/study_guide/Atomic-Structure.topicArticleId-10453,articleId-10447.html

Here is quantization of Bohr Magneton which is relevant.

http://en.wikipedia.org/wiki/Bohr_magneton :smile:

The electron cannot be in between two consecutive permissable orbits according to Bohr. It 'jumps' from one permissable orbit to another.

By anology on the number line, if you want to go from 1 to 2 you are not allowed to pass through any intermediate points in a smooth continuous fashion, you have to 'jump'. You are NOT allowed to occupy any intermediate point at any time.

A logical question one would ask is "how can you get from point A to point B without passing through any points in between A and B?" and the reply comes back "by performing a quantum jump"

Schrodinger voiced his objections to this idea in a famous quote-"If I knew we weren't going to be able to get rid of this damned quantum jumping I never would have involved myself in this business!"-Erwin Schrodinger
:smile:
 
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  • #75
The bohr model is inaccurate. Electron orbitals are probabilities, not circular orbits. As such it doesn't help us here. What exactly are you asking?
 
  • #76
boffinwannabe said:
as for collapsing the wave, has it not been shown this is when information becomes known? The delayed quantum eraser experiment showing it wasnt the measurement that collapsed the wave, it was when the information became available to the observer. I take this to mean the moon is nothing more than a probability wave until someone observes it.

I agree with you. In my opinion this is the philosophy behind quantum mechanics. I don't agree with the philosophy but i am not 'married' to my point of view. My opinion could change today, but i have yet to find evidence to change my mind. Many here say consciousness is not required. What is an observer then? According to some views posted here an observer can be anything. A quark, a gravitational field, a ray of light, an experimental apparatus, AI etc.:smile:
 
  • #77
agentredlum said:
I agree with you. In my opinion this is the philosophy behind quantum mechanics. I don't agree with the philosophy but i am not 'married' to my point of view. My opinion could change today, but i have yet to find evidence to change my mind. Many here say consciousness is not required. What is an observer then? According to some views posted here an observer can be anything. A quark, a gravitational field, a ray of light, an experimental apparatus, AI etc.:smile:

As this article states: http://en.wikipedia.org/wiki/Observer_(quantum_physics )

The issue of observation isn't completely agreed upon. Personally I can't see how anyone would believe that a conscious observer would be required, but I'm not a QM expert.
 
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  • #78
Drakkith said:
The bohr model is inaccurate. Electron orbitals are probabilities, not circular orbits. As such it doesn't help us here. What exactly are you asking?

quantum jumping is discrete, probability wave distributions are continuous. Q.M. wants both ideas and it seems to me that one idea makes the other impossible.
 
  • #79
agentredlum said:
quantum jumping is discrete, probability wave distributions are continuous. Q.M. wants both ideas and it seems to me that one idea makes the other impossible.

I don't see why you think that. If you look at a probability graph of an orbital, many of them aren't even physically connected between the lobes or whatever. How else would an electron get from one part of its orbital to another past a node without jumping?
 
  • #80
Look, is Quantum Mechanics a theory about discrete or continuous probabilities? If it is about continuous probabilities then the first word in Q.M. should be changed because in Latin Quanta means 'how much' and is used to describe a discrete value. This is why Quantum was chosen as the name for this science. By the way if you claim Q.M. is continuous then you better throw out all philosophical arguments that have discrete implications, like Planck length and Planck time.

Carefull here, i am not saying throw away the Planck constant. I am saying throw out statements like 'the smallest physical length allowed in this universe is the Planck length.':smile:
 
  • #81
I don't think you understand that just because things might be quantized, that doesn't mean that nothing can be continuous. The probability of where a particle might be is a continuous change, but in no way does that mean that the electron energy levels cannot be quantized.
 
  • #82
Drakkith said:
I don't see why you think that. If you look at a probability graph of an orbital, many of them aren't even physically connected between the lobes or whatever. How else would an electron get from one part of its orbital to another past a node without jumping?

Well that's what i mean. I find the jumping uncomfortable. You don't find it uncomfortable? I say again i am no expert. I can't see how the electron can move to a disconnected lobe like you say unless some kind of energy transmission or absortion is involved HYBRIDIZING the lobes. This is not too crazy an idea since an electron orbiting a nucleus is a moving charge and therefore creates a current. Also spins around itself and a spinning charge has a current associated with it.

Now I'm going to shock your mind. Professor Walter Lewin of MIT calculated the current produced by an electron going around the nucleus of a hydrogen atom using Bohr Magneton value and found 1.1x10^-3 A

A MILLI AMPERE! I was blown away!

I'm going to look for the lecture on MIT OCW and post the link:smile:
 
  • #83
agentredlum said:
The electron cannot be in between two consecutive permissable orbits according to Bohr. It 'jumps' from one permissable orbit to another.

By anology on the number line, if you want to go from 1 to 2 you are not allowed to pass through any intermediate points in a smooth continuous fashion, you have to 'jump'. You are NOT allowed to occupy any intermediate point at any time.

A logical question one would ask is "how can you get from point A to point B without passing through any points in between A and B?" and the reply comes back "by performing a quantum jump"
All of this fine. There's no problem with it.

You said:
agentredlum said:
If electrons are not permitted certain orbits then wouldn't that mean the probability of finding the electron at a non-permissable orbit should be zero?
So. Electrons jump discretely between orbitals. You will not find an electron in some in-between-orbitals state.

Orbitals physically overlap. Some are spherical some are dumbbell-shaped.


Some of those orbitals are large enough that part of them extend outside a container.

The upshot of this is that an electron, when measured, could still be within its orbital yet outside a container that the electron could not physically pass through (because it does not have enough energy). Once outside the container, it could be set free.

I would point out that this is not simply academic. The entire electronic industry of the planet is dependent on this process. Semiconductors, of which all computers have millions, work by electron tunneling.
 
  • #84
agentredlum said:
Well that's what i mean. I find the jumping uncomfortable. You don't find it uncomfortable? I say again i am no expert. I can't see how the electron can move to a disconnected lobe like you say unless some kind of energy transmission or absortion is involved HYBRIDIZING the lobes. This is not too crazy an idea since an electron orbiting a nucleus is a moving charge and therefore creates a current. Also spins around itself and a spinning charge has a current associated with it.

Nope, why would I? It's exactly what you would expect from a wavelike object.

Now I'm going to shock your mind. Professor Walter Lewin of MIT calculated the current produced by an electron going around the nucleus of a hydrogen atom using Bohr Magneton value and found 1.1x10^-3 A

A MILLI AMPERE! I was blown away!

I'm going to look for the lecture on MIT OCW and post the link:smile:

How is 1.1x10^-3 a million? Ins't that 0.0011 amps?
 
  • #85
Drakkith said:
Nope, why would I? It's exactly what you would expect from a wavelike object.
How is 1.1x10^-3 a million? Ins't that 0.0011 amps?

c'mon...I know you know what milli means...

Hey, I'm all in favor of 'question everything' but cmon...

Here is the link with this amazing derivation. Its at the beginning of the lecture.

http://www.archive.org/download/MIT8.02S02/wl-802-lec22-220k_512kb.mp4

:smile:
 
  • #87
DaveC426913 said:
All of this fine. There's no problem with it.

You said:

So. Electrons jump discretely between orbitals. You will not find an electron in some in-between-orbitals state.

Orbitals physically overlap. Some are spherical some are dumbbell-shaped.Some of those orbitals are large enough that part of them extend outside a container.

The upshot of this is that an electron, when measured, could still be within its orbital yet outside a container that the electron could not physically pass through (because it does not have enough energy). Once outside the container, it could be set free.

I would point out that this is not simply academic. The entire electronic industry of the planet is dependent on this process. Semiconductors, of which all computers have millions, work by electron tunneling.

"I'm afraid I can't do that Dave"-HAL 9000 from 2001 a space odessy-

i guess we're freinds again eh Dave...

:smile:
 
  • #88
Drakkith said:
Oh wow, I totally read a million lol.

Don't knock it though, a mA is an INCREDIBLE amount of current when compared to subatomic particles.

Please, please look at the lecture, you will not be disappointed.:smile:
 
  • #89
Drakkith said:
The issue of observation isn't completely agreed upon. Personally I can't see how anyone would believe that a conscious observer would be required, but I'm not a QM expert.

I totally agree. One thing that seems to have been completely forgotten in "conscious camp", is that life arouse on Earth 3.7 billion years ago, and I don’t know if an amoeba could be considered 'conscious'?? However, the universe is 13.7 billion years old, and the first star was lit approx 400,00 years after Big Bang, and AFAIK, it’s a 'little bit' complicated to imagine conscious life without stars... :bugeye:

500px-CMB_Timeline300_no_WMAP.jpg
 
  • #90
agentredlum said:
"I'm afraid I can't do that Dave"-HAL 9000 from 2001 a space odessy-

We might have slightly different 'views' on one or two things – but we all seem to have a great sense of humor! LOL :rofl:
(and I know Dave can take it, he’s an expert on the subject :smile:)

agentredlum, as Dave points out, a lot of your electronic gadgets is completely dependent on http://en.wikipedia.org/wiki/Quantum_tunnelling" ; computers, flash memory, etc, etc. You couldn’t have written one freaking comment in this thread without functional quantum tunneling, which constitutes pretty good evidence, if you ask me. Capice?

[URL]http://upload.wikimedia.org/wikipedia/commons/5/50/EffetTunnel.gif[/URL]

agentredlum said:
I find the jumping uncomfortable.

I think you’re mixing two different things... the (electron) jumping is an old an obsolete explanation. The idea of discrete quanta came from our common 'hero' Albert Einstein, and he got a Nobel for the photoelectric effect:

[URL]http://upload.wikimedia.org/wikipedia/commons/thumb/f/f5/Photoelectric_effect.svg/200px-Photoelectric_effect.svg.png[/URL]

And from this we got to the concept of http://en.wikipedia.org/wiki/Wave%E2%80%93particle_duality" .

In recent years there have even been double-slit experiments performed detecting individual single electrons, one by one!

Dr. Tonomura’s single electrons double-slit experiment
http://www.youtube.com/watch?v=FCoiyhC30bc&hd=1
https://www.youtube.com/watch?v=FCoiyhC30bc

Not much to discuss, huh? :wink:
 
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  • #91
Drakkith said:
I don't see why you think that. If you look at a probability graph of an orbital, many of them aren't even physically connected between the lobes or whatever. How else would an electron get from one part of its orbital to another past a node without jumping?

because as agentredlum pointed out, qm is digital and not analogue, it does say you go from one state to the next with nothing inbetween, time and space does not exsist between the states. This has given rise to digital physics.

And nobody in qm is saying conciousness is required for observation since qm is not able to even describe conciousness. btw we can operate without conciousness, just not as well as with it. QM deals with information, the rest is philosophy to interpret that as requiring conciousness. Its certainly not a requirement for processing information as proven by your computer being able to type your keystrokes.
 
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  • #92
boffinwannabe said:
because as agentredlum pointed out, qm is digital and not analogue, it does say you go from one state to the next with nothing inbetween, time and space does not exsist between the states. This has given rise to digital physics.

And nobody in qm is saying conciousness is required for observation since qm is not able to even describe conciousness. btw we can operate without conciousness, just not as well as with it. QM deals with information, the rest is philosophy to interpret that as requiring conciousness. Its certainly not a requirement for processing information as proven by your computer being able to type your keystrokes.

Umm, I'm 100% in agreement. Not sure why you would think I wasn't.
 
  • #93
yeah i confused myself there :confused:
 
  • #94
boffinwannabe said:
because as agentredlum pointed out, qm is digital and not analogue, it does say you go from one state to the next with nothing inbetween, time and space does not exsist between the states. This has given rise to digital physics.

And nobody in qm is saying conciousness is required for observation since qm is not able to even describe conciousness. btw we can operate without conciousness, just not as well as with it. QM deals with information, the rest is philosophy to interpret that as requiring conciousness. Its certainly not a requirement for processing information as proven by your computer being able to type your keystrokes.

How do you know what it's typing if you're not conscious of what it's typing?

Some of you here want the benefit of INTELLIGENCE without Consciousness.

I am not for or against consciosness in Q.M.

I am glad I am conscious. A universe devoid of consciousness would be a total waste. :smile:
 
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  • #95
What are you talking about agentredlum? Where did intelligence without consciousness come into this at let alone somehow apply to everyone?
 
  • #96
DevilsAvocado said:
I totally agree. One thing that seems to have been completely forgotten in "conscious camp", is that life arouse on Earth 3.7 billion years ago, and I don’t know if an amoeba could be considered 'conscious'?? However, the universe is 13.7 billion years old, and the first star was lit approx 400,00 years after Big Bang, and AFAIK, it’s a 'little bit' complicated to imagine conscious life without stars... :bugeye:

"In the beginning there were only probabilities. The universe could only come into existence if someone observed it. It does not matter that the observers turned up several billion years later. The universe exists because we are aware of it."-Martin Rees

I post this quote not because i agree with it, or disagree with it. I can't prove either way. This quote answers your observation that scientists in 'conscious camp' overlook something that seems obvious to you.

Martin Rees is currently Astronomer Royal and was President of The Royal Society from 2005 to 2010 so his credentials are impeccable.

http://en.wikipedia.org/wiki/Martin_Rees,_Baron_Rees_of_Ludlow
:smile:

I am editing this post because in my eagerness to provide a counterpoint i forgot to give you credit for the wonderful work you did putting post #89 and #90 together. Please accept my apology.
 
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  • #97
Drakkith said:
What are you talking about agentredlum? Where did intelligence without consciousness come into this at let alone somehow apply to everyone?

People here want to be able to verify experimental outcomes without using consciousness.

If you are not conscious of an experimental outcome, then what use is it to you?

How can you be intelligent and not conscious at the same time?:frown:
 
  • #98
What? No one here has suggested anything of the sort.
 
  • #99
agentredlum said:
"In the beginning there were only probabilities. The universe could only come into existence if someone observed it. It does not matter that the observers turned up several billion years later. The universe exists because we are aware of it."-Martin Rees

I post this quote not because i agree with it, or disagree with it. I can't prove either way. This quote answers your observation that scientists in 'conscious camp' overlook something that seems obvious to you.

Martin Rees is currently Astronomer Royal and was President of The Royal Society from 2005 to 2010 so his credentials are impeccable.

http://en.wikipedia.org/wiki/Martin_Rees,_Baron_Rees_of_Ludlow
:smile:

Martin Rees's quote is just too dumb, he must have been smoking PCP when he said that ****, or he just said it to see if anyone was indeed dumb enough to believe it.

So the universe came into being, and there was only probabilities, then observers were somehow made out of nonexistent probabilityness and then the universe was like "FINALLY, SOMEONE CARES ABOUT ME, I WILL STABILIZE".

Its actually the dumbest thing I've ever, EVER read.
His credentials doesn't mean anything other than the fact that the whole idea of "credentials" is as pointless as his flawed statement.
 
  • #100
Drakkith said:
What? No one here has suggested anything of the sort.

Well then what was boffinwannabe quote about and you AGREE 100%?

here i put first sentence of the quote you AGREED 100% with

And nobody in qm is saying conciousness is required for observation since qm is not able to even describe conciousness.

Before the word since he makes a claim about everybody in Q.M.
After the word observation he gives his opinion

I have posted evidence contrary to both of thes ideas, yet you agreed with him 100%...:cry:
 
  • #101
Fyzix said:
Martin Rees's quote is just too dumb, he must have been smoking PCP when he said that ****, or he just said it to see if anyone was indeed dumb enough to believe it.

So the universe came into being, and there was only probabilities, then observers were somehow made out of nonexistent probabilityness and then the universe was like "FINALLY, SOMEONE CARES ABOUT ME, I WILL STABILIZE".

Its actually the dumbest thing I've ever, EVER read.
His credentials doesn't mean anything other than the fact that the whole idea of "credentials" is as pointless as his flawed statement.

Well Fyzix, I suppose dummies get elevated to the position of MASTER OF TRINITY COLLEGE!

He earned his respect...
 
  • #102
I can say it another way than Professor Rees...you Q.M. people are going to like this...even though most of you probably won't admit to 'liking' Douglas Adams statement...

"The universe is a figment of it's OWN imagination"-Douglas Adams

LOL:biggrin:
 
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  • #103
agentredlum said:
I can say it another way than Professor Rees...you Q.M. people are going to like this...even though most of you probably won't admit to 'liking' my statement...

"The universe is a figment of it's OWN imagination"-agentredlum

LOL:biggrin:

... your statement isn't even original...
http://www.thinkgeek.com/homeoffice/stickers/3188/

You appeal to authority like it gives his stupid statement any creedence.
 
  • #104
agentredlum said:
Well then what was boffinwannabe quote about and you AGREE 100%?

here i put first sentence of the quote you AGREED 100% with

And nobody in qm is saying conciousness is required for observation since qm is not able to even describe conciousness.

Before the word since he makes a claim about everybody in Q.M.
After the word observation he gives his opinion

I have posted evidence contrary to both of thes ideas, yet you agreed with him 100%...:cry:

Observation doesn't refer to somethig with consciousness observing, it refers to any interaction. An electron passing by a proton observes it and vice versa.
 
  • #105
Fyzix said:
... your statement isn't even original...
http://www.thinkgeek.com/homeoffice/stickers/3188/

You appeal to authority like it gives his stupid statement any creedence.

Thanks for the heads up, I ddn't realize i must have seen it somewhere. I corrected the post.

You haven't presented any evidence supporting your opinion, why should we believe you?
 

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