One theory of identity posits that our identity is formed by the memories and experiences that we've seen in our lives. That our self is defined through a collection of experiences and images from life that constitute our identity.
The easy objection to that, however, is memory loss or diseases that cause similar effects.
Theseus' Ship: If an old ship is brought back to shore, and every last part of it replaced with new timber, sails, and rigging, is it still the same ship?
I am always becoming.
"You don't 'have a soul'; You are a Soul. You have a body."
Eonwind, we're not talking about thermodynamics, really. Quantum theory takes precedence as thermodynamics arises from it in a large scale limit.
The past exists but is of statistical nature (law of large numbers, which gives rise to thermodynamics). Your perceived past is the most likely past that resulted in the state you are in now. Which features an ever increasing entropy.
Basically, you are measuring your past only in the now and thus determining it. However, it is the most likely one.
And this is far from pseudo-scientific, it is as scientific as such talks get. Human consciousness unfortunately can't be put into a formula yet.
I also think the introduction and a better understanding of the second thermodynamic law especially in the relativity theory can make it possible to make the QED theory and relativity come closer to each other, perhaps ending all the silliness about possible time travels in the past.Mate, sorry, but that just nonsense. Thermodynamics is just statistics, and nothing else. There are no laws on its own, they are a consequence of the underlying theory. If you don't get that, it's best we don't further this argument.
I also think the introduction and a better understanding of the second thermodynamic law especially in the relativity theory can make it possible to make the QED theory and relativity come closer to each other, perhaps ending all the silliness about possible time travels in the past.Mate, sorry, but that just nonsense. Thermodynamics is just statistics, and nothing else. There are no laws on its own, they are a consequence of the underlying theory. If you don't get that, it's best we don't further this argument.
Pierre correctly understood what I meant, just a note about time: what I meant time in relativity is just a simple coordinate (sure, with a different sign) but it's otherwise equal to the space coordinates.
I understood Eonwind to be saying that a better understanding of why the second law of thermo (entropy always increases) holds could help stitch together QED and general relativity.
There are interesting physics papers out in the past year on the second law of thermo and why it holds, it's a valid scientific inquiry.
Stitching together QED and general relativity? That's just electromagnetism and gravity - why don't we see if it can unify all the forces, so include strong and weak? Anyway, I've no idea how that would be done.
But it would not surprise me if the second law was connected to the arrow of time (always heading to the future, I guess that is another way of stating the second law, not sure about this) which was somehow connected to the structure of spacetime (space and time are not on completely equal footings, there is a minus sign difference), which a better understanding of could point a way towards unifying gravity with the other forces.
Sure Thermodynamics is just statistics and QM/QED/... are they not???I also think the introduction and a better understanding of the second thermodynamic law especially in the relativity theory can make it possible to make the QED theory and relativity come closer to each other, perhaps ending all the silliness about possible time travels in the past.Mate, sorry, but that just nonsense. Thermodynamics is just statistics, and nothing else. There are no laws on its own, they are a consequence of the underlying theory. If you don't get that, it's best we don't further this argument.
Whatever you consider psuedo-science has always been an integral part of physics, interpreting whatever our model means for us. The many world interpretation or the Copenhagen interpretation are just two of those.Yes correct, whenever physics tries to interpret the meaning of a relativity equation telling us about physical phenomena is in its own right, when pretends to do the same with consciousness (which I say for the n-th time - is not even able to define it) or likely matters is pseudo-science.
My argument is (And perhaps you've heard a little about QFT and can follow) that as you can not say which state you were in precisely, as it is bound to be subject to quantum mechanical uncertainties (Heisenberg uncertainty principle) you must weigh all possible pasts according to their likelihood in order to determine a "physical" past. Only in the now you are truly observing sharply. The past and future are quite muddy.
I don't see any problems with time travel either, considering I can go around a building and return at the same point in space. Relativity is so much more than just a geometrical theory, it tells us, and to the best of our experimental capacity, that time and space are actually equal parts of spacetime.Lots of problem and paradox are created by past time travel, possibly including the break of some fundamental physic laws. Many thinks Relativity is a geometrical theory, and the fact that treats time and space in the same exact way (except for a sign) is one for the main reason why it cannot be merged with other theories like QED.
Eonwind, the whole laws of thermodynamics are derived from quantum statistics. Well, they were there before quantum mechanics, but these days one can derive the laws from quantum mechanics and statistics. The second law of thermodynamics is implied by unitarity of the quantum theory, thus whenever you have a unitary theory, the second law of thermodynamics holds.You're saying one thing and its contrary... the fact the thermodynamic laws can be derived from quantum mechanics, means they are coherent theories. My concern about the 2nd law is that a better understanding especially regarding relativity (and QED don't matter anything) may break the "symmetry" or equality between the space and time coords. I'm just speculating.
a) In fact, we CAN measure things in the past. And it has been done experimentally. It is called a quantum eraser.excuse me but where does it exactly say the measure are done in the past??
en.wikipedia.org/wiki/Delayed_choice_quantum_eraser
Then, the way time travel would be viewed is: Time and space are one, and you are traveling along a time-like curve on spacetime. You have a clock with you that gives you your "eigentime", i.e. the time you as an observer measure to pass.my speculation is nothing of the above is possible without introducing more dimensions, in fact I think there may be more than a single time dimension where quantum phenomenon may exist at the same time in different time dimensions (sort of time "parallel" universe) but going back in your actual "time line" would still be impossible.
However, the world is not just a set of four dimensional points. You, on your timeline, have also something that is an additional variable, i.e. your measurement of the world. Going back into the past (the same point in space time) occurs, according to your measurement, later than when you were there before.
On going back, there however is a different measurement of the world. You are back on the same point in spacetime, yet you measure a different world, namely one where you have travlled back in time.
I agree that extending these to something like consciousness is far from proper science, call it pseudo-science if you wish. But we are here to speculate on one of the biggest mysteries in life, anyway :DFeel free to speculate, but sorry I have fun when science is kicked in a discussion where it can barely say anything about. I repeat this is the field of philosophy not science, it's very funny (and honestly not very constructive imo) trying to use a tool (because I repeat science is a method, a tool) not fit for the use it's used for.
A speculation it is. The mainstream view is that relativity can be incorporated into a theory of quantum gravity, though. I tend to adhere to the mainstream in this regard. Also, note that there is relativistic thermodynamics, i.e. you can reproduce thermodynamics of relativistic systems by relativity and quantum mechanics. Thus, relativity and quantum mechanics are consistent.Eonwind, the whole laws of thermodynamics are derived from quantum statistics. Well, they were there before quantum mechanics, but these days one can derive the laws from quantum mechanics and statistics. The second law of thermodynamics is implied by unitarity of the quantum theory, thus whenever you have a unitary theory, the second law of thermodynamics holds.You're saying one thing and its contrary... the fact the thermodynamic laws can be derived from quantum mechanics, means they are coherent theories. My concern about the 2nd law is that a better understanding especially regarding relativity (and QED don't matter anything) may break the "symmetry" or equality between the space and time coords. I'm just speculating.
You do not seem to understand the setup of the experiment and causality. Take a look at the sections above in the article.a) In fact, we CAN measure things in the past. And it has been done experimentally. It is called a quantum eraser.excuse me but where does it exactly say the measure are done in the past??
en.wikipedia.org/wiki/Delayed_choice_quantum_eraser
On the contrary here say http://en.wikipedia.org/wiki/Delayed_choice_quantum_eraser#Does_delayed_choice_violate_causality.3F (http://en.wikipedia.org/wiki/Delayed_choice_quantum_eraser#Does_delayed_choice_violate_causality.3F) causality is not violated, which basically means chances to violate time sequence through quantum means are still science-fiction.
my speculation is nothing of the above is possible without introducing more dimensions, in fact I think there may be more than a single time dimension where quantum phenomenon may exist at the same time in different time dimensions (sort of time "parallel" universe) but going back in your actual "time line" would still be impossible.Agreed, I am myself quite open to the option of multiple time dimensions.
So in the end, going back to philosophy: you're doomed to stick to the choices you made in the past and live with it, no matter what you can only change the future and the science can't say this it's wrong; on the contrary all the experimental data from physic, to archeology to geology are coherent in telling us time travel in the past is still unheard of, and unlikely to be possible.It just means that the possibilities of violating reality are tiny, just as the possibility of all your atoms simultaneously tunneling through a doorway. That too is something unheard of.
Feel free to speculate, but sorry I have fun when science is kicked in a discussion where it can barely say anything about. I repeat this is the field of philosophy not science, it's very funny (and honestly not very constructive imo) trying to use a tool (because I repeat science is a method, a tool) not fit for the use it's used for.Philosophy and science go hand in hand. Without philosophy, you're not able to come up with new ideas and principles in science.
You do not seem to understand the setup of the experiment and causality. Take a look at the sections above in the article.
The setup is essentially two entangled photons going through a double slit. One is detected at some time, the other one is detected at a later moment. Depending on whether you choose to measure which path the the second photon took or not, you influence the outcome of the detection that has already taken place.
Yet this does not violate causality as the information from the first photon can only be extracted after the second photon has arrived, there is no faster than light or backwards time transfer of information. Which is just what causality states:
Information can only be relayed in a forward light cone, not faster than light, not backwards in time.
My point was that it is possible that the universe did not exist until just now and you just now observing it, which is pure speculation and just an amusing thought. In observing it, you would have also observed a past that conforms to the rules of quantum mechanics and thus thermodynamics.
Philosophy and science go hand in hand. Without philosophy, you're not able to come up with new ideas and principles in science.