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Gomar
2010-Aug-22, 04:07 AM
This sure makes sense:

http://www.huffingtonpost.com/robert-lanza/does-the-past-exist-yet-e_b_683103.html

NOT!

If it takes 20million years to invent a time machine, then eventually, time travelers would've been here, and ifcourse changed the outcome of 9/11. Or video taped Jesus, or Moses, or as they point out in the post JFK assassin's true identity would've been known.
Let's not forget other tragedies such as Titanic, WWI, WWII, floods, etc.

loglo
2010-Aug-22, 12:19 PM
That story wasn't worth the electrons it was written with. :)

Maha Vailo
2010-Aug-22, 12:28 PM
If the past was changed by time travelers, how would we in the present know? Maybe they've been there and we don't know.

- Maha Vailo

grant hutchison
2010-Aug-22, 12:49 PM
The writer isn't talking about time "travellers", but about the "spooky action at a distance" of quantum mechanics. According to QM, we can delay our choice of what measurement to perform on a photon until the very last second of a million-year journey. Our choice of measurement then "determines" whether it did a wave-like thing or a particle-like thing half a million years ago. We've got confirmatory evidence in the laboratory over shorter time scales, but haven't done the large scale experiment Wheeler proposed.
The rest is tired old quantum mysticism, just Schrödinger's Cat and Wigner's Friend writ large.

Grant Hutchison

grapes
2010-Aug-22, 02:33 PM
Worse, he mixes up his own interpretations with barely relevant quotes from famous physicists as if they were addressing the same notions. Not that I was fooled for a minute, but I could see where someone might be.

grant hutchison
2010-Aug-22, 03:01 PM
Worse, he mixes up his own interpretations with barely relevant quotes from famous physicists as if they were addressing the same notions. Not that I was fooled for a minute, but I could see where someone might be.Wheeler's "Participatory Universe" is often wheeled out to prop up the quantum mystics, even though Wheeler himself was quite clear that consciousness had nothing to do with quantum processes. But it's odd to see the younger Haldane pressed into service, with a partial quote (omitting "My own suspicion is that ...") and a first name he didn't use.

Grant Hutchison

mike alexander
2010-Aug-22, 04:08 PM
The author of the piece writes about similar subjects, I note (time, consciousness, quantum burritos). And the words flow, and the words flow.

TrAI
2010-Aug-22, 05:38 PM
Hmmm...

Seems to me that as the photons move at c they experience no flow of time, so perhaps they do not know in advance what they encounter, but rather the photon is in the exact same slice of time for the entire journey, so if the result of some interaction shows before it happens, it may be because the observer is in a different frame of reference from the photons, not due to some spooky transmission of the change into the past...

Garrison
2010-Aug-22, 05:46 PM
This sure makes sense:

http://www.huffingtonpost.com/robert-lanza/does-the-past-exist-yet-e_b_683103.html

NOT!

If it takes 20million years to invent a time machine, then eventually, time travelers would've been here, and ifcourse changed the outcome of 9/11. Or video taped Jesus, or Moses, or as they point out in the post JFK assassin's true identity would've been known.
Let's not forget other tragedies such as Titanic, WWI, WWII, floods, etc.

Leaving aside the mechanics your argument has two holes in terms of interfering time travelers. One, time travelers might interfere with unintended consequences, they prevent a terrible epidemic, which would have killed the infant Adolf, whom of course they would never have heard of. And of course after they've intefered they may no longer have the capability to undo it in the changed future. Second possibility is that they caused these events deliberately, either because their fanatics/lunatics or because there were worse events in their history, an all out nuclear conflict for example, that could only be prevented by causing one of those tragedies that then become part of our history.

forrest noble
2010-Aug-22, 07:14 PM
Time travel forward in time seems feasible, some kind of suspended animation possibly? But the idea of traveling backward in time seems ridiculous. Time might be thought of as a sequence of changes. To think that changing something that has already happened is possible, even in the slightest way, I believe is totally science fiction and the result of an over active imagination. It seems to me that the development of equations for theoretical physics often precedes the resulting logic, rather than the other way around where logic seemingly should be used as one of the tools to develop theoretical equations.

Sometimes backward time travel makes for an interesting sci-fi adventure though.

kleindoofy
2010-Aug-22, 08:22 PM
I once read a sign put on the blackboard of the history department at the University of Würzburg by a disgruntled professor:

"God is envious of historians on one issue: they can change the past."

Noclevername
2010-Aug-31, 02:07 AM
If it takes 20million years to invent a time machine, then eventually, time travelers would've been here, and ifcourse changed the outcome of 9/11. Or video taped Jesus, or Moses, or as they point out in the post JFK assassin's true identity would've been known.

20 million years from now, who's going to remember any of those things? They won't even be footnotes in history, because all of the past and present millenia of history itself will have long since been lost to the signal/noise ratio. H. Sapiens may not even be the dominant species by then.

Cougar
2010-Aug-31, 03:10 AM
If the past was changed by time travelers, how would we in the present know? Maybe they've been there and we don't know.

Humans have memories of the past. It is unclear how those would be "updated" if a traveler to the past changed something. If a large change was made and events started to be in conflict with people's memories, that would be rather disturbing. :insert appropriate emoticon here:

HenrikOlsen
2010-Aug-31, 12:15 PM
If time travel could change the past there'd be no memory of the unchanged world in anyone (except the time traveller if he experienced that time earlier in his own timeline) because they never experienced it.

People will keep tinkering with the past until a change cause a future where no time machine is ever invented or at least where all knowledge of all invented machines is lost again soon after the invention, possibly after setting up some stable loops of strange causality. Shat situation's stable and won't change anymore.

peledre
2010-Aug-31, 03:19 PM
Bob Lanza needs to stick to Biology as he clearly doesn't understand Quantum Theory.

Gomar
2010-Sep-04, 04:25 PM
they prevent a terrible epidemic, which would have killed the infant Adolf, whom of course they would never have heard of.

Your theory violates the basic theory that man does not make history, but history makes the man.
What it means is that if it hadnt been Hitler, then another maniac would have come on the scene, perhaps some general who would have honored the treaty with Russia and not attacked it. Hitler came close to being killed in WWI, and his mother wanted to have an abortion but just as the doc was about to begin she changed her mind and ran out of the hospital.

As for preventing bigger tragedies? Ok, what indeed was prevented by killing 3,000 people on 9/11?
Are you saying one of them might have a grandson who becomes conqueror of the world, or the pres of the US
who presses the big red button and sets off nukes because god told him to?
Or, how about this, a 15 year old pregnant girl was on one of the planes. She claims to be a virgin, and gives birth to the messiah. Thus, the saviour of mankind was killed before he was even born.
Or an unborn child was killed who would've found the cure for cancer or AIDS.

caveman1917
2010-Sep-05, 01:23 AM
Your theory violates the basic theory that man does not make history, but history makes the man.

But that basic theory would fly in the face of the expectations of chaos theory, or at least the sensitivity on initial conditions.
What if Hitler hadn't existed, and at the height of the power struggle with the communists (among others) the nazi's would've done something different, and lost. The communists win, attach to the USSR engulfing Poland as the whole thing goes. Why not?

billy2
2010-Sep-05, 02:03 AM
Perhaps travelling into the past is just a romantic notion born out of memory. What in our experience suggests that it is possible. Is there actually anything to travel back to?

Webbo
2010-Sep-05, 11:33 PM
If you did wish to travel back to an earlier time wouldn't you need to know exactly where the earth was at that point in history?

transreality
2010-Sep-05, 11:50 PM
say you had one of those jump drives from travellerRPG on your space ship, so you can travel a parsec or so in a week. So the ship travels past Earth at speed very close to C receives the local records, and the ~4 year old news coming from alpha C colony, and then jumps off to alpha C , allowing it to arrive a week or after the news was sent. It then can receive the news sent from earth by radio, then jump back to Earth arriving a week after the news was sent, and about eight years before the initial departure from earth, with the databanks containing information from the future.

ggremlin
2010-Sep-06, 12:11 AM
If time travel is even possible, why is it assumed that said traveler will appear on Earth?

Nevermind, I see that has already been pointed out.

MicVR
2010-Sep-06, 01:32 AM
What are you guys and gals talking about?
This thread is almost entirely off-topic as far as the cited article in the OP is concerned as grant hutchison correctly pointed out in post #4 of this thread.

Unfortunately, grant hutchison then goes on to say
The rest is tired old quantum mysticism, just Schrödinger's Cat and Wigner's Friend writ large.
That statement is incorrect. The article only makes one mention of Schrödinger's Cat:

This would be a situation much like the famous Schrödinger's cat experiment, in which the cat is both alive and dead − both possibilities exist until you open the box and investigate.
That statement in the article is accurate and has nothing to do with
tired old quantum mysticism whatever that may be...

The article is largely correct and grossly misrepresented in this thread.

Note: I have nothing to do with the author of the article. I don't know him and I had not read the article before stumbling upon this thread.

But since this board in general and this thread in particular may possibly be read by people seeking scientific advice I feel moved to put the posts in this thread into perspective.
Hence my statement that the article is largely correct (according to current understanding of quantum physics) and grossly misrepresented here.

Infinitenight2093
2010-Sep-06, 02:40 AM
This sure makes sense:

http://www.huffingtonpost.com/robert-lanza/does-the-past-exist-yet-e_b_683103.html

NOT!

If it takes 20million years to invent a time machine, then eventually, time travelers would've been here, and ifcourse changed the outcome of 9/11. Or video taped Jesus, or Moses, or as they point out in the post JFK assassin's true identity would've been known.
Let's not forget other tragedies such as Titanic, WWI, WWII, floods, etc.

you bring past time travel into your argument, yet you know nothing of past time travel. Nobody does. However, it is thought that if we could travel into the past, we would split off from the universe we were in and create an entirely separate reality, the one in which 9/11 never occurred, perhaps. That is obviously not our universe because 9/11 did occur. Also, the article has nothing to do with time travel. My own interpretation is that the past present and future are all dependent of each other, the future cannot exist without the past and the past cannot exist without the future, it makes perfect sense to me if you eliminate our very limited perspective of "time" . I also believe that the underlying idea of the article is that we are all living in separate realities. The fact that the future collapses into only a single event out of the infinitely many is because of certain characteristics that the observer carries (why do you have the opinions that you have?) Although another observer may interpret reality differently depending on who he/she is. There is also the question of why people 2 million years in the future would bother to change 9/11 or any other historical tragedy at all?

astromark
2010-Sep-06, 04:07 AM
These discussion's of time past present and future do become exercises in foolishness... It really is this simple... Historic record.

If a event has already happened it is part of history. It has already happened and as such can never be changed... Yes, I said 'Never.'

How there can be discussion of this is a form of madness I find irritating. Delusional madness., and stupidity.

This misguided suggestion of ever being able to change past events is not worthy of scientific analysis.. and is rightly classified as rubbish.

That such a view has even been given space in a scientific forum is an anomaly...

and NO apology is offered for my strong view. I see it as fact and science. Any discussion of this proposal is thus judged as ATM by me.

tnjrp
2010-Sep-06, 06:27 AM
Humans have memories of the past. It is unclear how those would be "updated" if a traveler to the past changed something. If a large change was made and events started to be in conflict with people's memories, that would be rather disturbing.A UFOlogist of some cloth once said this with a straight face in a documentary (of sorts anyway) when questioned about why the Rosswell crash left no sensible and obvious evidence of alien visitation... The aliens changed the past but brains of the witnesses, operating "outside of time", still remember the event.

Around that time I finally decided that UFOlogy has lost its snowball's chance in Hell to be accepted as valid science :)

Spoons
2010-Sep-06, 08:08 AM
20 million years from now, who's going to remember any of those things? They won't even be footnotes in history, because all of the past and present millenia of history itself will have long since been lost to the signal/noise ratio. H. Sapiens may not even be the dominant species by then.

It seems quite presumptuous to assume they'd care at all about changing things that people currently consider hugely significant but may very well end up relegated to footnotes in history. Change 9/11? Please. It's that important? I'd think the Black Plague would've garnered more consideration. JFK? By that time it may be lost in the records. Religious figures? By then people may have discarded with notions of religious importance.

What's to gain by changing the past? You would risk losing where you've gotten to. Tragedy fades.

Infinitenight2093
2010-Sep-06, 04:37 PM
These discussion's of time past present and future do become exercises in foolishness... It really is this simple... Historic record.

If a event has already happened it is part of history. It has already happened and as such can never be changed... Yes, I said 'Never.'

How there can be discussion of this is a form of madness I find irritating. Delusional madness., and stupidity.

This misguided suggestion of ever being able to change past events is not worthy of scientific analysis.. and is rightly classified as rubbish.

That such a view has even been given space in a scientific forum is an anomaly...

and NO apology is offered for my strong view. I see it as fact and science. Any discussion of this proposal is thus judged as ATM by me.

Well thats good for you. It is not about suddenly changing the past as events in the future unfold, that is impossible. I believe that it is about the past having already changed for each independent observer because of events in their future that are directly related to their past. But, of course, you will not agree with me or see the sense in this argument because you still cling to the narrow view that time must flow forward. The quote, "the universe is not only queerer than we suppose, but queerer than we can suppose", by John Haldane may not have been said about the article but it relates to it very well. The universe is the strangest place we know, therefore it requires some exceptionally strange answers.

CosmicUnderstanding
2010-Sep-06, 05:23 PM
There's no denying that. Right at this moment things are happening trillions upon trillons of miles away that would leave our jaw on the floor. Heck, my jaw drops every time I see a new Hubble photo.

I'm not saying time travel is possible, but how could we possibly rule it out so early on in our advacement of the sciences? Please bear in mind we still use wires attached to poles all over our globe for a lot of our power needs. We also drive engines that use combustion and produce pollution that harms our environment. How did we fly to the moon and back? Primitive combustion. We are in our technological infancy. 100 years ago we couldn't even escape the ground via planes! Less than 200 years ago we had SLAVES and it was completely LEGAL! We are so primitive we still engage in war constantly with one another. On a cosmological time scale that's like a pico or nanosecond of existence. I wish I was born just a mere 1,000 or 2,000 years ahead in the future. I feel so hopeless in this era of time we're currently experiencing. Not to be a debbie downer but I clearly see all around me just how unadvanced we really are on the grand scale. Of course this is a great moment to be alive as well and I wouldn't wish myself out of existence for anything. I want to live to see us explore other planets in our solar system, and to possible come up with new propulsion systems that would allow us to travel much farther, much faster in space.

Luckmeister
2010-Sep-07, 01:59 AM
Some in this thread talk about the future as though it exists. I see it as simply our anticipation of an upcomig "now" in time, and the past is simply our memory of previous "nows". They are both mental constructs we have developed to help us plan. Is there evidence that they are anything more than that? If so, please show me. I'd love to see it.

We are fooled into believing there is a past by seeing light from distant space. But it is impossible to join the past timeline we are observing. I wish it weren't so, but it appears it is.

Luckmeister
2010-Sep-07, 06:56 AM
I hope my last post didn't kill this thread. I didn't want to do that. I enjoy speculating about the cutting edge of science. I also love sci-fi, especially stories involving time travel, but my recent delving into of the nature of spacetime and observing our perceptions of the passage of time have led me to the reluctant conclusion that there is no past to go back to other than in our imagination. Go ahead and call me a pessimist, but I'm trying to be a realist.

If we did not have the mental capability to remember the past and anticipate the future, we would not be functional human beings. It's another example of how evolution has served us well. Our perception of the passage of time is part of everything we do, so of course the past and future seem like real entities to us. But I don't believe they are.

I see media-savvy theoretical physicists like Michio Kaku selling the hope for development of time travel into the past, and I suppose that's to be expected in an attempt to popularize science. I'm confident that there will always be many serious scientists who will jump at the chance to make a breakthrough in this area if new discoveries and capabilities warrant it. I'm glad that's the case, but I personally think it's a dead end.

I have no problem with SR. By increasing our speed relative to Earth, we can take advantage of a faster timeline and then return to this one many years ahead of the elapsed time we experienced while away. However, that will require traveling close to light speed, which is no small task. That violates no known laws of physics, but we have a more practical way of accomplishing a similar net result by perfecting suspended animation technology. And with that, we would simply go to sleep and wake up in the future without the long boring trip to endure, or the resulting loss of some of our personal lifespan.

For time travel into the past, I'd be happy to see a development that would prove me wrong. :)

Mike

DrChinese
2010-Sep-09, 02:49 PM
Some in this thread talk about the future as though it exists. I see it as simply our anticipation of an upcomig "now" in time, and the past is simply our memory of previous "nows". They are both mental constructs we have developed to help us plan. Is there evidence that they are anything more than that? If so, please show me. I'd love to see it.

We are fooled into believing there is a past by seeing light from distant space. But it is impossible to join the past timeline we are observing. I wish it weren't so, but it appears it is.

According to current orthodox quantum theory: not all histories of the past are set in stone. Some are still contingent on future events. So you cannot truly change the past, but you may be able to influence it. This is born out by experiment, for example delayed choice experiments. It is actually possible to entangle (for example in the polarization basis) photons that no longer exist. The decision to entangle or not is made afterward.

Gomar
2010-Sep-10, 03:15 AM
There is also the question of why people 2 million years in the future would bother to change 9/11 or any other historical tragedy at all?

Good point.
What if the Indians invent a time machine. Would they go back to 1491 and prevent Columbus from discovering America, thereby assuring that it remains a possession of the Indians?
What if a Jew invents it, would he/she try to kill Hitler when he was 10? (oh wait, Skynet has tried to Kill John Connor a few times and fails every time).
What if a black decides to go back in time to prevent slavery?
What if I go back to 1969, see Hendrix at Woodstock, and inform him he'll die in a year?

Spoons
2010-Sep-10, 03:58 AM
What if I go back to 1969, see Hendrix at Woodstock, and inform him he'll die in a year?

Don't do it! The man was depressed enough already.

astromark
2010-Sep-10, 08:04 AM
Well thats good for you. It is not about suddenly changing the past as events in the future unfold, that is impossible. I believe that it is about the past having already changed for each independent observer because of events in their future that are directly related to their past. But, of course, you will not agree with me or see the sense in this argument because you still cling to the narrow view that time must flow forward. The quote, "the universe is not only queerer than we suppose, but queerer than we can suppose", by John Haldane may not have been said about the article but it relates to it very well. The universe is the strangest place we know, therefore it requires some exceptionally strange answers.

You are absolutely correct... I do not agree with most of your post... It looks to me as you talk of other than the mainstream view...

That you agree the past events can not be undone or changed... then we are on the same page..

but then, Time must flow forward... yes that is my view. I am not a photon.

Some say I have too much mass to move quickly... Hmmm... :clap:true.

and with no multi verses... this is it. Here we are. Then there was... and one day there will be.

BUT you can not change what has already gone... No. The past can not be changed., but you can tell lies about it....:eh:

whimsyfree
2010-Sep-10, 09:07 AM
Don't do it! The man was depressed enough already.

Yep, could cause depression eventually leading him to overdose on sleeping pills.

grant hutchison
2010-Sep-16, 06:36 PM
My apologies, I seem to have entirely missed the continuation of discussion on this thread. In particular:
Unfortunately, grant hutchison then goes on to say

The rest is tired old quantum mysticism, just Schrödinger's Cat and Wigner's Friend writ large.
That statement is incorrect. The article only makes one mention of Schrödinger's Cat:
Perhaps you misunderstand my use of the phrase "writ large"? The article is an extended decription of quantum superposition and observation, both of which are also involved in the parables of Schrödinger's Cat and Wigner's Friend. Extended version of the same thing: hence, "writ large".


That statement in the article is accurate and has nothing to do with

tired old quantum mysticism
whatever that may be...
You say it has nothing to do with quantum mysticism, but you don't know what quantum mysticism is? How do you manage to be so categorical about that?
"Quantum mysticism" is a departure from strict "shut up and calculate" QM, which strays into ideas of human observers having some sort of responsibility for the generation of the Universe, or some aspects of it, by playing the role of "observer". It's been around for a long time, and it hasn't provided much enlightment in all that time: hence, "tired old". It's a philosophical stance in relation to QM, not an aspect of QM itself, and it provides much of the content of the article.


Note: I have nothing to do with the author of the article. I don't know him and I had not read the article before stumbling upon this thread.You should perhaps acquaint yourself with the author and his other writings on Biocentrism; context is important.


Hence my statement that the article is largely correct (according to current understanding of quantum physics) and grossly misrepresented here.So you feel that "... you might even collapse realities that determine whether Noah's Ark sank" is a direct, unavoidable implication of QM?

I see elsewhere (http://www.bautforum.com/showthread.php/107751-BAUT-Review-for-Parents-and-Teachers) that you're on a bit of a crusade against dogmatism here at BAUT, but I'd suggest you've chosen the wrong person and the wrong fight on this occasion. :)

Grant Hutchison

nokton
2010-Sep-16, 08:11 PM
Some in this thread talk about the future as though it exists. I see it as simply our anticipation of an upcomig "now" in time, and the past is simply our memory of previous "nows". They are both mental constructs we have developed to help us plan. Is there evidence that they are anything more than that? If so, please show me. I'd love to see it.

We are fooled into believing there is a past by seeing light from distant space. But it is impossible to join the past timeline we are observing. I wish it weren't so, but it appears it is.
Luckmeister, you really should know by now that our knowledge of spacetime and the universe is incomplete,
there is a theory that the past and present and future are really one and the same thing, we just have not
ability to comprehend it.
Nokton

grant hutchison
2010-Sep-17, 12:45 PM
So you feel that "... you might even collapse realities that determine whether Noah's Ark sank" is a direct, unavoidable implication of QM?Just a little more on this question of mine, since it speaks directly to Lanza's quantum mysticism.
There's something very odd indeed, by the standards of "regular" QM, and even by the specific "consciousness collapses the wavefunction" interpretation of QM, about Lanza's closing statements:
Choices you haven't made yet might determine which of your childhood friends are still alive, or whether your dog got hit by a car yesterday. In fact, you might even collapse realities that determine whether Noah's Ark sank.We might ask why your friend's consciousness doesn't adequately collapse the wavefunction of her own existence; or the consciousness of those who attend her funeral. Does the dog's consciousness not suffice to collapse its own wavefunction? If not, the driver of the car or anyone else who sees the dog should do the job. The biblical-literal Noah's Ark was well-enough populated for its wavefunction to be nicely collapsed at all times, not to mention the consciousness of everyone in the world who is descended from biblical-literal Noah. To all that, we must add that QM itself says nothing about conscious observers: many physicists use the interpretation that events on a sufficiently macroscopic scale simply make a transition to classical behaviour. Under that interpretation of QM these past events are all done and dusted as soon as they happened. Under "conscious collapse", they're set in classical stone once their consequences are "observed" by a suitable consciousness.
So why does Lanza think that only "you" can create the reality of your own past?
See his What Happens When You Die? Evidence Suggests Time Simply Reboots (http://www.huffingtonpost.com/robert-lanza/what-happens-when-you-die_b_596600.html):
But if the world is observer-created, we shouldn't be surprised that it's destroyed with each of us. Nor should we be surprised that space and time vanish, and with them all Newtonian conceptions of order and prediction.Lanza has taken the QM ball and run all the way to solipsism with it: according to him, we each create our own realities. If my reality disappears when I die, and your reality presumably keeps on going, then they are independent of each other. My friend may die in her own reality, but live on in mine; or live in her reality and die in mine.

This could be used as the type-specimen for quantum mysticism, were there not so many other good examples which take precedence.

Grant Hutchison