OK, so here's the anti-matter thing, just by itself.

[Hielor]

Agreed. Suppose if you paused a state and reversed the velocities of every particle no matter how small. (lets assume no outside fields either) I highly doubt that you will see many chemical reactions reverse themselves at all and instead will find yourself at a state fundamentally similar to where you would be if you hadn't reversed the particles.

Indeed. Additionally, if you reversed the velocities of the pieces of the shattered egg that cjp mentioned (also reversing the effect of gravity for the duration of the "rewind"), they wouldn't reassemble themselves into a whole egg, they would fly back to form a whole egg momentarily before continuing on that new path (thus "imploding"). They wouldn't magically stitch themselves together again.

 

[originalpckelly]

As the name indicates, the spin has originally been thought of as a rotation of particles around their own axis. This picture is correct insofar as spins obey the same mathematical laws as do quantized angular momenta. On the other hand, spins have some peculiar properties that distinguish them from orbital angular momenta: spins may have half-integer quantum numbers, and the spin of charged particles is associated with a magnetic dipole moment in a way (g-factor different from 1) that is incompatible with classical physics.

Anyone who claims to break symmetry is simply not logical. It is simple idea, something is equal to itself. If you sincerely want to dispute that, be my guest. It's a matter of simple logic.

Of course, what am I to expect from people who think they can even come close to a theory of everything from observing one planet up close and personal, a moon via a few guys who landed on it, and the planets while observed by robots. We haven't even made it to another star! And we think we can have a theory of everything? :rofl:

This is all to one degree a bit of humor, as it would have to be. They accidentally the whole universe. Is this bad?

I think my lack of qualifications makes it necessary to publish these ideas in the form of science fiction, to lay the groundwork for real scientists to come along and figure out that 0 = 0.

 

[Hielor]

Anyone who claims to break symmetry is simply not logical. It is simple idea, something is equal to itself. If you sincerely want to dispute that, be my guest. It's a matter of simple logic.

Here, watch as I smash an egg on the counter. Whoops, I just broke symmetry. There goes your theory.

Of course, what am I to expect from people who think they can even come close to a theory of everything from observing one planet up close and personal, a moon via a few guys who landed on it, and the planets while observed by robots. We haven't even made it to another star! And we think we can have a theory of everything? :rofl:

And if doing all that does not qualify people to have a "theory of everything," how does sitting on your arse all day just thinking and not actually doing any real academic research on the topic qualify you to come up with a "theory of everything?"

 

[Eagle]

Anyone who claims to break symmetry is simply not logical. It is simple idea, something is equal to itself. If you sincerely want to dispute that, be my guest. It's a matter of simple logic.

Simple ideas are often simply wrong.
Elegent ideas are often inelegently wrong.

Just because we've only sent probes into the edge of the interstellar medium doesn't mean we haven't observed further than that. Yes science makes a lot if inferences, but good science makes sure that there is a solid rationale behind it.

For example: Current cosmological theory of the Universe (nevermind my redundancy) assumes that the rest of the Universe at distances beyond what we observe looks pretty much the same as the nearby Universe. Now this assumption is likely wrong, but it could be mostly true...also we have no other example of what else it could look like! You could speculate, but unless you can make some predictions that could be observed or experimentaly tested in the next million years the point is likely moot.

---------- Post added at 09:26 PM ---------- Previous post was at 08:57 PM ----------

Most of the people on Orbiter-Forum are not idiots. The physicists who are working on these theories are even smarter (with the exception of Orbiteers who are physicists).

 

[Artlav]

Anyone who claims to break symmetry is simply not logical. It is simple idea, something is equal to itself. If you sincerely want to dispute that, be my guest. It's a matter of simple logic.

Simple logic breaks the symmetry. There are things that exist, but there exist nothing that don't exist.

The Universe is similar to itself across all scales, it's the depth of understanding that matters, not the scale observed - observing distant stars could help, but is not a necessity in understanding the non-clockworks of the universe.

Suppose we stopped time right now, and started reversing it. What would we expect, based on the laws of physics, if we didn't know we reversed time? Some things are perfectly reasonable, like reversing the rotation of the earth, but we wouldn't expect things like broken eggs that 'un-break', and 'un-decaying' of particles, because that would violate the second law of thermodynamics. In other words, they would be very improbable.

I have a problem with that.
First, why should you "reverse" time? Who said that it doesn't run in different or both directions at once?

A man remember today that yesterday he didn't know what will happen today.
Yesterday, a man don't know that he don't remember what would happen tomorrow.
So, the time could be running in circles or cycloid, or whatever set of directions, but we will only notice a seemingly - steady "flow" forwards.

Second, all laws of physics seems to be symmetric wrt to the time reversal.
Why the hell not the second law of thermodynamics?

 

[Eagle]

I have a problem with that.
First, why should you "reverse" time? Who said that it doesn't run in different or both directions at once?

...

Second, all laws of physics seems to be symmetric wrt to the time reversal.
Why the hell not the second law of thermodynamics?

That only works if the current state holds enough information to describe all of the previous states without ambiguity. I don't think that's the case.

Consider two droplets of liquid in a zero g environment encased in a fully reflective shell so no energy is lost thorough radiation (atmosphere is at the vapor pressure so there is no evaporation). Assume that both have momenta that sum to zero. The two droplets collide and merge into one droplet. We wait a long time for the system to mix. Maybe even on the order of decades.

So we look into our system and we see a single droplet at the center and the whole system is at a certain temperature. All we have is the energy of the collision. We don't know if it was two equally sized drops at the same speed, a faster small drop and slower big drop, we can't even tell the direction of the collision.

We can always find a solution, but are we finding the solution?

Note:This does not violate the conservation of information. No information is created or destroyed, it just enters a state of ambiguous origin.

 

[Artlav]

That only works if the current state holds enough information to describe all of the previous states without ambiguity. I don't think that's the case.
...
So we look into our system and we see a single droplet at the center and the whole system is at a certain temperature. All we have is the energy of the collision. We don't know if it was two equally sized drops at the same speed, a faster small drop and slower big drop, we can't even tell the direction of the collision.

You're thinking in your/experimenter point of view, and true enough, you can't measure the parameters of the atoms in that system good enough to backtrace the event a decade prior.
You measure ("observe") the system, you change it.

But, why should there be ambiguity if noone interferes?
Uncertainty principle doesn't state that the parameters are undefined or random, only that both of them can't be measured precisely at the same time.

So, even if the decays are "random", their result will still be reversible - whatever atoms decayed in the liquid will be re-made, all the motions and mixing will backtrace, and at some point known for us, the imaginers of the experiment, the drops will split again.

The point is not that someone will measure everything and backtrace, but the universe - a closed, unobserved system - having it's time flow in another direction - big difference.

---------- Post added at 10:39 AM ---------- Previous post was at 10:35 AM ----------

No information is created or destroyed, it just enters a state of ambiguous origin.

Define origin of information, btw.
If the system can't determine it's prior state, it lost information.

 

[tblaxland]

Uncertainty principle doesn't state that the parameters are undefined or random, only that both of them can't be measured precisely at the same time.

So, even if the decays are "random", their result will still be reversible - whatever atoms decayed in the liquid will be re-made, all the motions and mixing will backtrace, and at some point known for us, the imaginers of the experiment, the drops will split again.

Um, no. The position and momentum of a particle are actually uncertain and interacting with other particles restricts one or the other within the bounds of the uncertainty principle. Its like the old question: if a tree falls in the forest and nobody hears it, does it still make a noise. The answer is yes because there is always other matter around that "hears" the sound (like other trees, for example). Conscious observation is does not hold some special place in the uncertainty principle. Why should it?

 

[Artlav]

Conscious observation is does not hold some special place in the uncertainty principle. Why should it?

Precisely.
The problem is, once again, that we are not talking about an experiment we measure, but a closed system reversing.

So, every other atom hears what every other atom does.
Now, turn the time backwards, and all the information will go the opposite direction, backtracing the system the same way it was run forwards.

 

[Quick_Nick]

Alright, I felt like throwing this in earlier regarding the hexagon and whatnot, and I think I'll do it now.
Regarding the hexagon, and in this case the snowflake: http://www.wolframscience.com/nksonline/section-8.2
(after a few views, it might ask to register, and you might as well)
This likely doesn't have much to do with too many subjects of this thread, but explains some things maybe. Click Table of Contents for some more interesting, mostly off-topic, info. (some other pages might relate to this too though)

It's true that the link shows that nature DOES indeed use hexagons sometimes, but it doesn't necessarily show that the hexagon is as big a deal as you have been making it.

 

[cjp]

Precisely.
The problem is, once again, that we are not talking about an experiment we measure, but a closed system reversing.

With 'closed system', you mean the entire universe, right?

And the question is then: will reversal of time(*) give you the past, or will it give you a (different) future?

In classical mechanics, it will clearly give you the past, assuming you exactly preserved the state information of all particles. Even the slightest difference will give huge differences in the outcome.

So the discussion is now about quantum mechanics, right? Is quantum mechanics fundamentally asymmetric w.r.t. time?

I'm familiar with the Copenhagen interpretation of quantum mechanics. This describes a 'wavefunction collapse' at a measurement, which looks like it destroys state information.

I wonder, if you have an experiment where you subsequently measure two 'incompatible' (non-commuting) properties of a particle (e.g. position and momentum), what it would look like with reversed time, and whether it can still properly be described by the Copenhagen interpretation. I think it can, but I haven't figured out the details yet.

(*) I'm not sure whether it is already clearly defined what this means. In classical mechanics, where the state of particles is described by position and velocity, you could e.g. do this by multiplying all velocities with -1.

PS.
Interesting page: http://en.wikipedia.org/wiki/T-symmetry
It seems there is some small fundamental time-asymmetry in quantum mechanics.
This looks like most things we see in nature: it is almost symmetrical, but it always has one ugly spot that isn't symmetric.

Edit:read this: http://en.wikipedia.org/wiki/CPT_symmetry
As far as I can see, that's a symmetry which hasn't been broken yet..

 

[Eagle]

But, why should there be ambiguity if noone interferes?

...

Define origin of information, btw.
If the system can't determine it's prior state, it lost information.

The answer depends if it is possible to reach exact same state from more than one starting position.

Consider the droplet experiment again, at some time t all of the liquid is in a single drop that is resonating from the impact. Can you generate the same frequency by colliding two slightly colder droplets moving slightly faster? (same net energy). At first the colder, faster collision will have a resonant amplitude, but will become identical as it dampens. What if it was never two droplets but you instead created a warm liquid shape and quickly removed the mold?


On a tangent there is class of states colloquially called 'Garden of Eden' where there does not exist any possible previous states which could generate it.

 

[Artlav]

Consider the droplet experiment again, at some time t all of the liquid is in a single drop that is resonating from the impact. Can you generate the same frequency by colliding two slightly colder droplets moving slightly faster? (same net energy). At first the colder, faster collision will have a resonant amplitude, but will become identical as it dampens. What if it was never two droplets but you instead created a warm liquid shape and quickly removed the mold?

Where do you think the energy will go?
Dampen? Dissipate?
I thought we were talking about a closed system.

What we will have in the droplet case is a new big droplet at equilibrium of radiating and absorbing, with atoms inside moving around, not some precise resonant state.

Now, if these motions of atoms are backtraced, the original droplets will re-emerge.

It seems you're thinking on the level of temperature and balance, instead of the level of atomic motion, and down there looks-alike and the same are two different things.

 

[Eagle]

Where do you think the energy will go?
Dampen? Dissipate?
I thought we were talking about a closed system.

What we will have in the droplet case is a new big droplet at equilibrium of radiating and absorbing, with atoms inside moving around, not some precise resonant state.

Now, if these motions of atoms are backtraced, the original droplets will re-emerge.

It seems you're thinking on the level of temperature and balance, instead of the level of atomic motion, and down there looks-alike and the same are two different things.

The viscosity and surface tension of the liquid itself dampens occupations. The energy of the oscillations is translated into heat.

 

[Artlav]

The viscosity and surface tension of the liquid itself dampens occupations. The energy of the oscillations is translated into heat.

Macroscopic effects.
Where do you think the heat will go?
Back into the droplet, getting the atoms excited again, keeping the same, unique, chaotic motion containing all the information of it's past states.

 

[originalpckelly]

There are two or three possibilities here, ones even the morons like me can get:
1. The universe is a closed system, and there must be a necessary conservation of everything. (0 = universe - universe.)
2. What we observe as the universe is not a closed system, and that is either due to incomplete observations (almost certainly true) or interaction with an external agent (aka God.)

It's utterly ridiculous to suggest that a closed system has "random" things going on it. Complex and impossible to predict is different from truly random. If you want to argue that the universe isn't closed, then state clearly why you think it isn't. Isn't it odd how we can't just magically conjure energy out of nowhere? The problem with quantum physics is that it doesn't explain common sense. Why is it that the planets can have both their position and their momentum well understood? Isn't that the idea of Heisenberg uncertainty principle?

Why don't planets blink out on one side of their orbits, and blink in on the other?

Relativity, even GR, is classical physics. The ideas of relativity, if I get it right, are there to reconcile the problems of observers with the laws of physics. That the laws of physics should be true from all perspectives (from all frames of reference.)

What we are doing is having the old dice debate. It's the thing that made me go into music. I was in search of a theory of everything, and I wanted to play with the other kids, and that means Dr. + post-Doc to be "credible". The problem with our society is that we give people credibility regardless of what they say simply because of their degrees. It's not to say that someone with a degree is a moron or on the same level as a crank like me, it's to say that they only achieve credibility by proving what they're saying. A degree is a measure of possible knowledge or ability to apply it, not a measure of one's credibility. No one should have inherent credibility.

If a theory of everything, which is exactly what something like Quantum Gravity or String Theory holds itself out to be, is like any other theory, it is only as good as its evidence. I may no longer know anything of merit about physics, if I ever did, but I do recall that that's true, even for the ideas of brilliant people. That a theory is only as good as its evidence.

We are still finding things out about our planet, still to this day, discovering new species. If we haven't even figured out Earth, how can we figure out the whole universe? (Trying is fun, but always include caveats along with the ideas that come from trying.)

These people are nuts if they think they can break symmetry. It doesn't matter how it applies, they are basically saying the foundation of the math they use to express these ideas is totally untrue. They might as well pack up and go home if that's true. Breaking symmetry is precisely like saying 0 = 658 or 2+2 = 5, that is if the universe is a zero sum game. I ask how it could be anything other than that, and of course the things I list above are the reasons.

This is why I now love music, it is what it is. Either the score or the recording or the performance. Even if you have an Ashlee Simpson situation, someone somewhere had to make the music.

Oh yes, by the way, the Emperor is without apparel, and Orbiter rocks!

 

[Artlav]

(0 = universe - universe.)
...
that is if the universe is a zero sum game. I ask how it could be anything other than that, and of course the things I list above are the reasons.

I didn't follow how do you come to that conclusion?

Antimatter is still matter, symmetric part of a thing is still a thing.
A universe is still an existence.

And, there is no non-existence to counter it.

 

[originalpckelly]

I didn't follow how do you come to that conclusion?

Antimatter is still matter, symmetric part of a thing is still a thing.
A universe is still an existence.

And, there is no non-existence to counter it.

You raise an interesting question by your statement, one which made smoke come out of my ears.

Perhaps what you're saying is not exactly true. This is just wild speculation, and it wouldn't be totally accurate, but what is a vacuum after all?

Of course, that's not entirely true, as I understand it, vacuums anywhere are really not perfect. There's always something there.

On the other hand, not everything is located in a single area either.

You put it in terms of "existence" which makes it sound like a philosophical question. I'd rather refer to it as energy density.

There indeed are vast areas with low energy density, perhaps to counter areas with high energy density. There is no 0 energy density area, just like there is no 1/1 energy density area (1/1 refers to the maximum energy density of the entire universe being compressed to a single area.)

So complete non-existence as you put it, is not necessary, but existence as a word really limits you into an "or" choice, like some kind of binary (think black and white.) Everything is not that simple, I would argue.

Back to that science fiction work, I think I'm going to do a science fiction album. I don't think I've heard of too many of those things.

Let's hope the screechiness of my voice, and sloppy guitar playing don't entirely cause the message to be lost.

 

[Urwumpe]

Why do you insist on using energy density of local areas for describing the whole universe? The energy content of the whole universe is the interesting value then.

Your trouble with energy density will start already when dealing with vacuum energy. There is obviously no matter in a vacuum, but how can there be energy, if there is the mass energy equivalence? Field energy is also accounted by the mass energy equivalence.

Also: Antimatter is not negative energy. A -universe does not exist. 500 kg antimatter + 500 kg matter are not forming 0 kg mass, but actually 1000 kg mass. The same problem applies to your concept of "there has to be regions of lower energy density to compensate regions of high energy density". If you have only a limited amount of energy, which is not evenly distributed in the universe, you will have regions with less than average and more than average. A stupid tautology.

Next: the whole universe can be inside a single volume. The volume just needs to be large enough. Everything can be inside a single volume. You can have 1/1 "energy density" if you have spanned the volume around the whole universe.

But a trick question: Would that mean that regions of 0/1 "energy density" are outside the universe?

 

[Moonwalker]

If you run time in reverse, will an electron's spin be the same?

You can run a recorded event or a clock in reverse, mechanically. But you can't do anything with the time itself, because time is just an illusion. Neither the past, nor the future does exist. There is just one condition that continuously changes, which we call present. The future or the past just exists in our brains as an illusion of a state/condition of something that might happen or as a memory of a state/condition that has already been changed. But it never stops, nor does it begin. How long is the present? One day? One hour? One breath? One second, a millionth, a billionth, a trillionth second or even or less, or maybe more then? Not even the pyhsics tells you that. Just the simultaneousness of events is definable.

I think that the present also exists if nothing would exist (matter, the universe...). Even if you just have a big black and dark nothing. There is always the capability that something can happen (see the big bang, if it ever really happened the way some think it did). Most humans are just incapable to imagine that. I'm even confident enough to call Einstein, Hawking and other ordinary mortals incapable in some ways.

Like time and time travel, many other things are just human illusions and theories too, which can be nicely put into numbers and human defined laws partly. But things around us will always be well ahead of our capabilities.