[Topgun]

I am starting to really, really like MW1 interpretation of quantum mechanics, but it has one issue that just keeps bugging me.
It can't be falsified, it also explains things too easily. Like why the universe is almost entirely made up of matter. one solution that MW1 provides is that we can't observe a universe made of equal parts matter and antimatter because then we wouldn't be alive to observe such a universe.

That's too easy.
Now I personally don't care too much if something can be falseified or not but still...
What do you guys think?

[Dilmah G]

Am I the only one who thought MW1 = Call of Duty 4: Modern Warfare?

[Mongoose]

Am I the only one who thought MW1 = Call of Duty 4: Modern Warfare?

Nope.

[General Battuta]

That's basically the issue with many worlds - it's a nice fantasy.

It also seems to clash with basic cosmology for me. Depending on how you interpret 'universe'.

Oh and it's wildly overinterpreted as applying at the macroscopic level. Flipping a coin will not split the universe. Something like particle decay will.

[Topgun]

Flipping a coin will not split the universe. Something like particle decay will.

Now, I am not very educated in QM, but I disagree here. The coin is made up of subatomic particles and so is everything around the coin that affects how it lands. Maybe, a long time ago, a radioactive isotope decayed a little in such a way that it would affect the coin toss. Basically its a want for a nail scenario. And since you didn't observe the isotope decaying the universe doesn't split until you made the coin toss, essentially observing the isotope decaying.

At least thats how I understand it.

[Bobboau]

well, wouldn't the vigintillions of electromagnetic interactions involved in a coin flip each split the universe?

[Topgun]

On a side note it would be really cool if MW was true and that I could communicate with different version of myself. I could flip a coin to determine if I will do homework or not. the version of me that gets heads will not do homework while the version of me that gets tails will do the homework and then send the other me a copy of the answers

I would only need to do homework half the time

[General Battuta]

Flipping a coin will not split the universe. Something like particle decay will.

Now, I am not very educated in QM, but I disagree here. The coin is made up of subatomic particles and so is everything around the coin that affects how it lands. Maybe, a long time ago, a radioactive isotope decayed a little in such a way that it would affect the coin toss. Basically its a want for a nail scenario. And since you didn't observe the isotope decaying the universe doesn't split until you made the coin toss, essentially observing the isotope decaying.

At least thats how I understand it.

You understand it wrong. You could argue that the universe splits for the behavior of every constituent particle in the coin that behaves in a probabilistic manner when measured, but particles are constantly measuring each other. The coin itself has no meaning whatsoever as an entity. It does not exist at the quantum level. All that exists is a haze of particles, connected by force carriers.

This is my problem with QM. People forget the Q - it applies only at tiny scales, to tiny things. Macro scale entities are meaningless in all but the most extreme cases.

On a side note it would be really cool if MW was true and that I could communicate with different version of myself. I could flip a coin to determine if I will do homework or not. the version of me that gets heads will not do homework while the version of me that gets tails will do the homework and then send the other me a copy of the answers

I would only need to do homework half the time

Flipping the coin is not probabilistic. There is no quantum coherence to the system, so waveform collapse cannot occur and MW is an explanation for waveform collapse. That's all it does.

[Topgun]

But there must be a reality that is exactly the same only with the coin toss result flipped, right?

[General Battuta]

But there must be a reality that is exactly the same only with the coin toss result flipped, right?

Yes, just as there is a reality where a high-energy cosmic ray with the kinetic energy of a softball strikes you in the head and kills you as you try to flip the coin. Sheer chance guarantees this. But it will not arise as a result of you flipping the coin; it is not the other branch of your universe that budded off a second ago.

You are making the mistake of thinking the branching would have anything to do with macroscopic events. The branches would (probably) occur at the microscopic level, uncountable gazillions of times in every Planck time length, each time a waveform collapsed.

But bear in mind that Many Worlds is an untestable, meaningless explanation for a total handwave. Waveform collapse itself is an ugly kludge forced onto quantum mechanics.

[Topgun]

But bear in mind that Many Worlds is an untestable, meaningless explanation for a total handwave. Waveform collapse itself is an ugly kludge forced onto quantum mechanics.

I wouldn't say it is untestable, if there was a way to force what reality you end up in or if there was a way to communicate with other versions of ourselves, I would call that evidence. but like I said it can't be falsified.

[Mongoose]

Now that I actually know what we're talking about here, for anyone who's into animu, I highly recommend the series Noein, which is essentially centered around a macroscopic application of the many-worlds interpretation.  It (loosely) uses a number of the more esoteric (read: crazy) quantum interpretations and concepts, but it's evident that the creators did some research beforehand.  Fun stuff.

[General Battuta]

But bear in mind that Many Worlds is an untestable, meaningless explanation for a total handwave. Waveform collapse itself is an ugly kludge forced onto quantum mechanics.

I wouldn't say it is untestable, if there was a way to force what reality you end up in or if there was a way to communicate with other versions of ourselves, I would call that evidence. but like I said it can't be falsified.

But the scenarios you're postulating are problematic on their own. What do you mean what reality 'you' end up in? You do not exist at the quantum level. You are a haze of bound particles, each of which would be creating a new universe when it underwent waveform collapse. At any given Planck moment the particles that make up your body are undergoing countless such events.

[Akalabeth Angel]

Am I the only one who thought MW1 = Call of Duty 4: Modern Warfare?

Nope, but I thought it meant Mechwarrior

[Bobboau]

does a carbon-dioxide molecule exist at the quantum level?

[Sarafan]

Am I the only one who thought MW1 = Call of Duty 4: Modern Warfare?

Nope, but I thought it meant Mechwarrior

+1

[watsisname]

does a carbon-dioxide molecule exist at the quantum level?

I dislike people trying to label one size/class of object as existing at the quantum level or not.  Quantum mechanics isn't like a form of physics that only applies to one thing.  Rather, it applies everywhere, much like special relativity does.  Just as you can apply special relativity to every day life and get back to newton's laws, you can also apply quantum mechanics to large objects and still get the correct answers.

Example:  Try describing something big, like the moon, with QM and you'll find that the moon can only exist in certain allowable orbits.  But you'll find that the difference from one allowable orbit to the next is smaller than the width of a proton.  Much too small to be worth worrying about.

So to answer your question, sure, the CO2 molecule "exists at the quantum level", but it's still (mostly, I think) describable through classical mechanics.  But if you want to look at the elementary particles within the atoms of that molecule though, then classical physics will not work anymore.

[General Battuta]

does a carbon-dioxide molecule exist at the quantum level?

I dislike people trying to label one size/class of object as existing at the quantum level or not.  Quantum mechanics isn't like a form of physics that only applies to one thing.  Rather, it applies everywhere, much like special relativity does.  Just as you can apply special relativity to every day life and get back to newton's laws, you can also apply quantum mechanics to large objects and still get the correct answers.

Example:  Try describing something big, like the moon, with QM and you'll find that the moon can only exist in certain allowable orbits.  But you'll find that the difference from one allowable orbit to the next is smaller than the width of a proton.  Much too small to be worth worrying about.

So to answer your question, sure, the CO2 molecule "exists at the quantum level", but it's still (mostly, I think) describable through classical mechanics.  But if you want to look at the elementary particles within the atoms of that molecule though, then classical physics will not work anymore.

*sigh*

The entire point of waveform collapse is a kludge to make QM merge into real-world classical/relativistic behavior.

[Ghostavo]

To reiterate, general relativity and quantum mechanics cannot both be right.

[General Battuta]

To reiterate, general relativity and quantum mechanics cannot both be right.

Sort of. The problem you hit is a divide by zero error when you try to combine the two. But they can both be 'right' in the sense that they are both aspects of a fundamental theory of everything which resolves the problem - in the same way Newtonian mechanics are still 'right' in the scope that Newtonian mechanics generally works in, i.e. low velocities and small masses.