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Quantum Weirdness 103: How Many Worlds?// Summer Rerun

“He who laughs has not yet heard the bad news.”–Bertold Brecht

The good news is, this is the last of the current series of summer reruns.  The bad news is, that means vacation is over and I have to go back to work.  Grumble.

“There is no question that there is an unseen world. The problem is, how far is it from midtown and how late is it open?” –Woody Allen

For the quantum physics-uninitiated, get ready for the weirdest of the weird: the many worlds interpretation of quantum mechanics.

In Quantum Weirdness 101, we talked about the wave-particle duality of sub-atomic quanta, and how they appear to be in a superposition of every possible trajectory and location until an observer measures them.

In Quantum Weirdness 102, we discussed The Copenhagen Interpretation, which basically states that reality is just fuzzy on that level.  They are only potential trajectories–probabilities–interfering with each other, and this doesn’t have a measurable effect on our everyday macro world.   But we also visited Schrödinger’s infamous cat–the mind experiment that poked a colossal hole in  Copenhagen.

Image Credit: University of Oregon, 21st Century Science

The Copenhagen interpretation remained the most popular explanation for decades, in spite of Schrödinger.   But in 1957 cosmologist Hugh Everett made an astonishing proposal.  He suggested that the particles themselves–not merely their probabilities–interfere with one-another.  In this interpretation, they actually take every possible trajectory, each in an alternate universe.  Effectively every physically possible history exists in a huge–possibly infinite–number of alternate universes. So when we look in the box containing that possibly dead or alive cat it is actually in two universes: alive in one, dead in the other.   We just see it in the one we are in.   Taken to the extreme, every one of us would exist in a countless number of alternate universes.   Some would be imperceptibly different from ours, in others we might not even recognize ourselves or the the world around us.  And while Everett was mostly ignored or derided in his day, his many worlds interpretation has become a leading explanation of quantum weirdness, rivaling even Copenhagen.

So where do I stand?  Agnostic.  It is a rather optimistic world view.  I hope it’s true; I’m afraid it isn’t.  But many of the world’s top physicists now lean towards many worlds, and David Deutsch, among others, makes some very convincing arguments using deductive reasoning if not direct evidence.  I will leave it at this: it is a strong possibility that greatly influences my millennium conjectures. For more detailed background, check out the Wikipedia articles on The Many Worlds interpretation,  as well as general overview of quantum mechanics interpretations.   Or if you prefer, here is an entertaining video, shamelessly lifted from YouTube.

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Quantum Weirdness 102: Equal Time for the Cat// Summer Rerun

“I don’t like it, and I’m sorry I ever had anything to do with it.”
Erwin Schrödinger  (referring to Quantum Mechanics).

What better follow up to The Equation of Canine Chaos, then the infamous tale of Schrodinger’s Cat?

In Quantum Weirdness 101, we saw that the double-slit experiment revealed the wave-particle duality of sub-atomic quanta, and the fact that these troublesome little bits behave as if they are everywhere they could possibly be at once until an observer looks for them.  While the experimental proof that this happens is rock-solid, the explanation for what causes it is anything but.  For decades after its original discovery in the 1920’s, the predominant interpretation—essentially, in fact, the only one—was the so-called Copenhagen Interpretation.  It essentially states that the universe is just fuzzy on the sub-atomic level, it doesn’t affect our everyday macro-world, and we mortals should not worry about it otherwise.  Critics have said it is really no interpretation, and some facetiously call it the “shut-up-and-calculate” interpretation.   In 1935, Erwin Schrodinger posed perhaps the most famous mind experiment in all of physics to show that theoretically the Copenhagen Interpretation makes no sense.  More recently, physicists have been able to succeed in creating this quantum superposition with larger and larger bits of matter, which tends to shoot empirical holes in Copenhagen.

Anyway, this witty video does a good job of explaining the concept behind Schrodinger’s Cat.  And I’m pretty sure that no cats were harmed in its making—much to the chagrin of my dogs.

In the next installment: the many worlds interpretation of quantum weirdness.

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Vacation Rerun: Quantum Weirdness 102, Equal Time for the Cat

Where’s Waldo?

By the time this post goes winging outward to the vastness of cyberspace,  Cheryl and I will be winging our way home from distant parts unknown. The next new post will return to the subject matter below, so bone up and be ready for brain cramps.

“I don’t like it, and I’m sorry I ever had anything to do with it.”
Erwin Schrödinger  (referring to Quantum Mechanics).

What better follow up to The Equation of Canine Chaos, then the infamous tale of Schrodinger’s Cat?

In Quantum Weirdness 101, we saw that the double-slit experiment revealed the wave-particle duality of sub-atomic quanta, and the fact that these troublesome little bits behave as if they are everywhere they could possibly be at once until an observer looks for them.  While the experimental proof that this happens is rock-solid, the explanation for what causes it is anything but.  For decades after its original discovery in the 1920’s, the predominant interpretation—essentially, in fact, the only one—was the so-called Copenhagen Interpretation.  It essentially states that the universe is just fuzzy on the sub-atomic level, it doesn’t affect our everyday macro-world, and we mortals should not worry about it otherwise.  Critics have said it is really no interpretation, and some facetiously call it the “shut-up-and-calculate” interpretation.   In 1935, Erwin Schrodinger posed perhaps the most famous mind experiment in all of physics to show that theoretically the Copenhagen Interpretation makes no sense.  More recently, physicists have been able to succeed in creating this quantum superposition with larger and larger bits of matter, which tends to shoot empirical holes in Copenhagen.

Anyway, this witty video does a good job of explaining the concept behind Schrodinger’s Cat.  And I’m pretty sure that no cats were harmed in its making—much to the chagrin of my dogs.

(Video Credit: Open University, on You Tube)

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Quantum Weirdness 103: How Many Worlds?

“There is no question that there is an unseen world. The problem is, how far is it from midtown and how late is it open?” –Woody Allen

For the quantum physics-uninitiated, get ready for the weirdest of the weird: the many worlds interpretation of quantum mechanics.

In Quantum Weirdness 101, we talked about the wave-particle duality of sub-atomic quanta, and how they appear to be in a superposition of every possible trajectory and location until an observer measures them.

In Quantum Weirdness 102, we discussed The Copenhagen Interpretation, which basically states that reality is just fuzzy on that level.  They are only potential trajectories–probabilities–interfering with each other, and this doesn’t have a measurable effect on our everyday macro world.   But we also visited Schrödinger’s infamous cat–the mind experiment that poked a colossal hole in  Copenhagen.

Image Credit: University of Oregon, 21st Century Science

The Copenhagen interpretation remained the most popular explanation for decades, in spite of Schrödinger.   But in 1957 cosmologist Hugh Everett made an astonishing proposal.  He suggested that the particles themselves–not merely their probabilities–interfere with one-another.  In this interpretation, they actually take every possible trajectory, each in an alternate universe.  Effectively every physically possible history exists in a huge–possibly infinite–number of alternate universes. So when we look in the box containing that possibly dead or alive cat it is actually in two universes: alive in one, dead in the other.   We just see it in the one we are in.   Taken to the extreme, every one of us would exist in a countless number of alternate universes.   Some would be imperceptibly different from ours, in others we might not even recognize ourselves or the the world around us.  And while Everett was mostly ignored or derided in his day, his many worlds interpretation has become a leading explanation of quantum weirdness, rivaling even Copenhagen.

So where do I stand?  Agnostic.  It is a rather optimistic world view.  I hope it’s true; I’m afraid it isn’t.  But many of the world’s top physicists now lean towards many worlds, and David Deutsch, among others, makes some very convincing arguments using deductive reasoning if not direct evidence.  I will leave it at this: it is a strong possibility that greatly influences my millennium conjectures. For more detailed background, check out the Wikipedia articles on The Many Worlds interpretation,  as well as general overview of quantum mechanics interpretations.   Or if you prefer, here is an entertaining video, shamelessly lifted from YouTube.

post

Quantum Weirdness 102: Equal Time for the Cat

“I don’t like it, and I’m sorry I ever had anything to do with it.”
Erwin Schrödinger  (referring to Quantum Mechanics).

What better follow up to The Equation of Canine Chaos, then the infamous tale of Schrodinger’s Cat?

In Quantum Weirdness 101, we saw that the double-slit experiment revealed the wave-particle duality of sub-atomic quanta, and the fact that these troublesome little bits behave as if they are everywhere they could possibly be at once until an observer looks for them.  While the experimental proof that this happens is rock-solid, the explanation for what causes it is anything but.  For decades after its original discovery in the 1920’s, the predominant interpretation—essentially, in fact, the only one—was the so-called Copenhagen Interpretation.  It essentially states that the universe is just fuzzy on the sub-atomic level, it doesn’t affect our everyday macro-world, and we mortals should not worry about it otherwise.  Critics have said it is really no interpretation, and some facetiously call it the “shut-up-and-calculate” interpretation.   In 1935, Erwin Schrodinger posed perhaps the most famous mind experiment in all of physics to show that theoretically the Copenhagen Interpretation makes no sense.  More recently, physicists have been able to succeed in creating this quantum superposition with larger and larger bits of matter, which tends to shoot empirical holes in Copenhagen.

Anyway, this witty video does a good job of explaining the concept behind Schrodinger’s Cat.  And I’m pretty sure that no cats were harmed in its making—much to the chagrin of my dogs.

In the next installment: the many worlds interpretation of quantum weirdness.

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