“OK, Teena, can you guess why I had you put those different things on different steps?”

“Oh, another game of Which of these things aren’t the same!  I love those!  So we’ve got a marble on one step; a tennis ball, a yo-yo and a ring-toss ring on the second step; and a softball and a ring-in-a-ring on the third step.”

“Don’t forget we’re pretending the softball is hollow with a ping-pong ball floating in its middle.”

“I didn’t forget, Uncle Sy.  Uh… everything’s round, so that can’t be it.  Wait, there’s round-like-a-ball and round-like-a-donut, but we’ve got donut-thingies on two steps. … Oh!  The marble doesn’t have any empty places inside, the tennis ball has one and the softball has two.  Is that it?  But the other things don’t fit.”

“I’m sorry, I wasn’t fair with you ’cause I didn’t tell you about another rule.  See how yo-yo and donut shapes have a pinch-in-the-middle?  We call that a node and it counts as one empty place.”

“Wait, we forgot about the way-far-away empty place.  That counts for all of them, too, right?”

“Good remembering, that’s absolutely right.  It’s a node, too.”

<dancing about, singing>  “Then I know the answer, I know the answer!  The step number is the number of empty places, um, nodes.  The marble on the first step has one.  The tennis ball and the yo-yo and the ring on the second step have two, and the third-step things have three.  See that, Mommie?”

“Very good, Sweetie.  So what’s that got to do with colors, Sy?”

“Suppose we’re looking at a murmuration —”

“My lovely, lovely new word —”

“Yes, Teena.  Suppose for some reason we’d put a big hunk of bird food up on a tall pole.  Birds would fly to make a tight ball around the top of that pole.  Which of Teena’s toys would it look like?”

“Like that marble.”

“That’s right, no node in the middle.  Now suppose we want to get the birds away from the pole.  What could we do and what would the murmuration look like?”

“Set off a firecracker in the middle.  BOOM and all the birds fly away!”

“If they all fly the same distance, which toy would that look like?”

“The tennis ball!  BOOM and a tennis ball shape!  BOOM!”

“Settle down, Sweetie.  I suppose someone could make noise at the foot of the pole…. That would make a half-dumbbell shape as the birds fly upward.”

“Right on, Sis.  One more possibility — we could send a noisy drone to fly circles above the pole.”

“The birds would make a bigger circle between the drone’s orbit and the ground.  Oh!  Your donut shape.”

“Each way, the murmuration changes to a shape with one additional node and we go up a step.  And when we stop annoying the birds?”

“They fly right back to the food.  Ah, I see where you’re going.  They form that ball shape again and we have fewer nodes.  Now, about the colors…”

“Teena, do you think a murmuration could have half a node?”

“No, that’d be silly.”

“Absolutely right.  There’s no in-between step on the stairway, and there’s no in-between shape in an atom.”

“Wait, you mean that whenever an atom goes from a, say 2-node shape to a 3-node shape, that’s the famous quantum jump?”

“Yup, and the jump-down is, too.  Teena, let’s put all the toys back in your toy box and try an experiment.”

“OK … done!”

“Good job.  Now get up on the second step and jump down to the first one.  Make it a loud jump.”

“Sy!”

“Just this once, Sis, for demonstration purposes.”

“OK, just this once, Teena, and never again!”

“Yay!” <THUMP>

“So what’s that prove?”

“That energy is released when you go down a step or allow a murmuration to fill in an empty space.  Teena’s jump released sound energy.  Atoms release light energy when their charge cloud — ‘scuse me, Teena, quantum murmuration — goes to a shape with fewer nodes.  And the amount of energy for each different node-count change is always the same.”

“I think I see where you’re headed.  Each different jump makes a different color?”

“Sis, you’re as smart as I’ve always said you are.”

~~ Rich Olcott

“What’s another quantum rule, Uncle Sy?”

“Uhh…  Oh, look what the birds are doing now, Teena — flying back and forth between those two fields.”“I think one side looks like a whale jumping out of the water, and the other side looks like the tail end of a buffalo or something.”

“Well, I can’t argue with that.  Look, though — the murmuration’s acting like it’s caught between two barriers of some kind.  That reminds me of another rule.  When you’re one of those tiny quantum things, it matters if you’re caught between barriers.”

“I’d want to be free so I could go wherever I want to.”

“Freedom’s nice for people but it must be boring for quantum things.  The rule says that a particle that doesn’t have any barriers just goes in a straight line forever and ever.  No stopping for lunch, never anyone to talk to, just traveling on and on.”

“Yeah, that’d be boring, all right.  What’s the rule say for when there’s barriers?”

“It depends on the barriers, what their shapes are and how far apart they are.  The general situation, though, is that there’s usually some forbidden regions, places where the particle can’t go.”

“Oooo, forbidden.  So spooky.  What happens to the particles who go there anyway?  Does something catch them and do bad things to them?”

“You’ve been watching too many horror movies.  No doing bad things but no trying to go into a forbidden area anyway.  Physics particles don’t have choice in the matter — they just can’t enter those places.  Almost can’t.”

“I heard ‘almost.’  Are you being sneaky?”

“No, just trying to keep things simple.  There’s something called ‘tunneling,’ where a particle that’s on one side of a barrier can sometimes somehow get to the other side of the barrier without going through it.  It’s one of the big puzzles in quantum mechanics.”

“Can’t it climb over, like I climb over fences?  (Shh, don’t tell Mommy.)”

“I suspect she already knows, Mommies are good at that, and I’m sure she’s praying that you’re being careful about which fences to climb and how you do it.”

“I am.  I only climb friendly fences that don’t have angry dogs behind them.”

“Good strategy, I feel better now.”

“If quantum thingies are even smaller than water-bear eggs, what do you make the barriers out of?”

“People don’t make the barriers, they’re just there, part of how the Universe works.  Um… Those little blocks you have that push each other away or pull together depending on how you point them…?”

“My rainbow blocks!  I love them.  Sometimes it’s hard to build something with them because you have to set one in a space just right or it’ll jump out.”

“Mm-hm.  Well, that push-or-pull force is called magnetism, and some of the barriers are made of that.”

“But that’s not a real thing!”

“Not something you can pick up, no, but the quantum things feel it and that’s what counts.  If the Universe didn’t have magnetism and forces related to it, we wouldn’t have rocks or stars or us.”

“I guess I’m happy that the barriers give quantum thingies places they can’t go.”

‘Just to make things more complicated, a lot of the forbidden places aren’t even where the barriers are.”

“Huh?”

“Like I said, it depends on the shape of the barriers.  If you’ve got two that face each other, there could be a forbidden place maybe in the middle, or two forbidden places a third of the way from each side, or three or four, all the way up.  And here’s a weird case that’s really important.  Ready to stretch your brain?”

“Just a minute … NNGGGGGH!  OK, I’m ready.”

“For an atom one of those barriers is infinitely far away.”

“Infinitely??!?  My brain doesn’t stretch that far!”

“How about really, really far and let it go at that?  Anyway, atom barriers give us colors.”

“Now my head hurts.”

“Oh dear, better let your brain unstretch.  Hey look, the birds are flying off to roost in the woods ’cause it’s getting dark.  And it smells like your Mommy’s got dinner ready.  Time to go inside.”

“Mommy, can Uncle Sy stay for dinner with us?”

~~ Rich Olcott

 

“Hey, Uncle Sy, what’s quantum?”

“That’s a big question for a small person, Teena.  Where’d you hear that word?”

“You and Mommy were talking and you said that something had to do with quantum mechanics.  I know car mechanics work on cars so I want to know what the quantum mechanics work on.”

“That’s a fun question, Sweetie, because there actually is a kind of car called a Quantum.  Not very many of them and they’re made in England so you don’t often see one here.  But the quantum mechanics we were talking about is completely different.  I’ll take it one word at a time, OK?”

<sigh> “OK, but let’s sit on the porch swing, I can tell this will take a while.”

“Oh, it’s not going to be that bad.  You know what mechanisms are, right?”

“Um.. they’re not like people or animals and they’re not like my tablet thingie…. They’ve got gears and things.”

“Good enough.  A big part of physics is thinking about how mechanisms work and that’s called ‘mechanics.’  There’s lots of different kinds of mechanisms.  Each kind has a different kind of mechanics, like ‘celestial mechanics’ which is thinking about how stars and planets move, and ‘fluid mechanics’ which is thinking about how liquids and gases move.  With me so far?”

“So quantum mechanics is thinking about how quantums move.  But what’s a quantum?”

“Quantum isn’t a thing, it’s a set of rules that add up to be a theory.  The first rule is, it only applies to things that are very, very small.  That’s what the word ‘quantum’ has come to mean — the smallest possible amount of something.  So quantum rules apply to quantum-sized things.”

“As small as my water bears?”

“Much smaller.  Things that are as small compared to a water bear as a water bear egg is small compared to you.  Things like molecules and atoms, and those are made of lots of parts that are even way smaller.”

“Ooo, that’s teeny.  How do you even see them?”

“Well, you don’t.  They’re far too small to see even with a microscope.  It’s worse — if you did try to see an atom’s parts, any light you could shine on them would move them around so they’re not where they were when you started to look.”

“Then how do the quantum mechanics people learn about them?”

“Umm…  Ah! See that flock of birds flying past?”

“Mommy says they’re starlings but I think they’re blackbirds.”

“Could be either or both, it’s hard to tell when they’re in the air like that.  Sometimes the two kinds flock together.  If it’s a flock of starlings, the flock is called a murmuration, which is one of my favorite words.”

“Oh, that’ll be one of my favorites now, too.  Murmuration, mmmurmuration, mmmm.  I love  ‘M‘ words.”

“Anyway, can you see what direction any one bird is flying?”

“No, there’s too many and they go back and forth and it’s too confusing and I like the shapes the whole murmuration makes.”

“But can you point to the middle of it and see how the pattern moves?”

“It’s right the— ooo, look, it did a spiral!”

“Murmurations are sorta like the kind of thing the quantum mechanics people work with.  They look at lots and lots of quantum-size things to see how the typical ones and the special ones behave.  Then they try to work out what the behavior rules are.  Sometimes the rules are really simple, like the rules the birds use.”

“Birds use rules?  I thought they could fly wherever they wanted to.”

“Sometimes they do, but if they’re flying in a murmuration they definitely follow rules.  Most of them.  Most of the time.  If I were one of those birds, I’d stay about the same distance from each of my neighbor birds, I’d usually fly in about the same direction as my neighbors are flying, and I’d also aim at about the middle of the flo— murmuration.  Scientists have found that just those three rules account for most of how a murmuration behaves.  Cool, huh?”

“Simple rules for bird brains, that’s funny!”

“But look at the beautiful shapes those simple rules make.”

~~ Rich Olcott