Version: 2017-07-21 6845c3f
Purpose: Seeking a minimum viable page UI, so folks can provide an initial sanity check on the ideas. Conversation fodder.

Size down to atoms, then nucleons up to materials

Let's explore some ideas for improving K-13 chemistry education content.

Thank you for your interest, and for your help with whatever I asked you about.

My focus is on what is possible, not what is currently economic to create, or plausible to deploy. I speculate most everyone is underestimating how much better science education content could hypothetically be. I'd like to explore that.

So why bother? I used to say, I'm setting someone else up to do an NSF exploratory research grant. But now, tech constraints are about to change. VR/AR and spoken dialog systems are coming. If there are opportunities to piggyback transformational changes on them, changes which wouldn't soon happen otherwise, they need to be explored for.

"nucleons-up!?!" - a caution: If you are a physics postdoc, and thought "Teach nucleons to kids!?! Absurd! Muons! Hartree–Fock!"... just no. Think "nuclei are little balls". As in, teaching "traffic lights" in kindergarten means "red is stop; green is go", not communication theory, network flow, or "highway standards documents, in Chinese". This has surprisingly come up repeatedly.

Web browsers often render millimeters incorrectly: If the millimeter grids are off, you can zoom the page. For this sketch, I didn't want to deal with users doing calibration.

This page was written to establish a context for some conversations. I wanted to brainstorm a "nucleons-up" ("scale down to atoms, and nucleons up through materials") approach to teaching atoms, down towards early primary, with a couple of MIT and Harvard researchers and educators. Just for exploration. Writing something up before hand was regrettably necessary. This is not content, nor a learning progression, just crufty little whiteboard sketches to create a conversational context. Plus some scope creep down a slippery slope.

Please don't get hung up on superficial aspects of this web page. What matters is the approach. This is a crappy long page with cards. If I'd found better discussion management code, this might instead have been a short dynamic page with a spoken conversational interface, usable only in Chrome/ium. If my WebVR stack was more mature, this might have been VR/AR, and I'd be lending you a Vive headset. The medium is very not the message here, but it's easy to get distracted by it.

"I can't picture young children learning that!" Hearing "teach nucleons", a postdoc pictured chalking quantum math on a graduate seminar blackboard. Hearing "teach atoms", a teacher pictured memorizing and regurgitating 4th-grade nonsense definitions. This page is perhaps a long exercise in "no no, picture approaching that from this other direction - doesn't it seem it might have nice properties?". To set up brainstorming conversations around: "Could we maybe do something like this? What might be hard? What might it look like? What other opportunities might exist? How might we build on them? What might it buy us?".

The "Preview" video: is just a fast teaser, but it helps clarify context.

Why "A Warning"? It has been more than a decade since science education research surprised us with how badly science education was failing students. But even now, how often are students told? Instead, K-13 students have been left to think their confusion and cluelessness, are strictly their own fault, their own failing.** Left to think science is boring. They are not told that these are known defects of the wretched content we're giving them. At what point does failing to notify them become an ethical failure?

**This gets mentioned a lot when doing adult user testing.

What is this page?

Here are some speculative ideas for improving K-13 science education supplemental content. It's an extremely early rough draft. Folks asked for something written so they could give better feedback.

Caution: I am not an educator. Nor a science researcher. I'm just a software engineer who enjoys research talks. This is a hobby project. These ideas are untried, untested, and there is little reason to believe any of it might work.

A Warning

Science education does not work well. Science education content confuses both teachers and students, leaving both deeply steeped in misconceptions.

This page is unlikely to be any better.

Atoms are,
little balls,
sticky little balls that jiggle.


We'll see all these videos later.

Now let's look at little.

How to remember sizes

Here is a way to remember the sizes of small things, down to atoms.

Introduction with waving hands

Introduction with waving hands

What is this? These are user test videos left over from a 2015 project. No single approach tested well, so they weren't finished. Here, they are sliced up and combined into several overlapping introductions, each taking a slightly different approach.

Making size accessible: If I ask you "how big is your cup?", you're not likely to think bucket or thimble. You've handled cups; they're familiar. Well, two 1000x zooms gets us down to atoms looking like sand. Tell enough stories in those two views, and the objects in them become familiar too. Size might serve as a framework for anchoring knowledge. And by building on a foundation of a thing's physical object-ness, we might reduce the need for definition and abstraction. But it never user tested well without a good teacher. And VR/AR changes the design space.

Arms, hand, fingernail, tiny excerpts
What is micro view?
Sugar crystals come in different sizes
and have different uses.
A story in micro view.

Introduction with blah blah

Introduction with whiteboard and views
We'll zoom things to scale views excerpts

We'll mostly use micro view and nano view, but also an extra nucleons view.

What is micro view?
The same video as above.
Sugar crystals come in different sizes
and have different uses.
A story in micro view. The same video as above.
What is nano view? excerpts

Introduction with graphpaper

Introduction with graph paper

We'll imagine zooming things so we can hold them.
And think about what they look like.
And sometimes we'll imagine putting them on a table, on top of graph paper.

"What do atoms look like in nano view?"
(sand, table salt, table sugar, ...)

buildings view
------- 10 m
real view ------- 10 mm
micro view
------- 10 um
red blood cell
nano view ------- 10 nm
atoms view ------- 10 pm
Hydrogen electron density
nucleons view ------- 10 fm
Neon nucleus
(in slooowwww motion)

Introduction with scale model toys

Introduction with scale model toys
Scale models

How do we play with things that are too big to play with? Like cars, and people, and trains?

We imagine shrinking them smaller, and play with scale models. Like toy cars, and dolls, and toy trains.

So how do we play with things that are tiny, or tinier than tiny? We imagine stretching them bigger.

Here is a way to remember the sizes of small things, down to atoms. We'll imagine zooming things so they are big enough to play with.
Scaling by 1000x

Different scales are good for different things. Bigger toy cars may have more details and moving parts. Smaller toy cards are easier to make roads for. Bigger dolls are easier to create tools and accessories for. Smaller dolls are easier to make rooms and bulldozers for.

Here we'll use scaling by 1000x, because it's good for remembering.

We'll use several scale views. Each one is like a toy playset - all the things in it are zoomed to the same scale.

We won't much use the planets view or cities view, but will use an additional nucleons view.

We'll sometimes use other scales too. But we'll talk about that later.
We'll zoom things to scale views excerpts
The same video as above.

Scale views

buildings view

buildings view
meters in your hands

If you imagine zooming things a thousand times smaller... this is buildings view.

PDF printable.
The building is
slightly too small.
How big is a building in buildings view?
buildings view ------- 10 m
Hand size!
Or fingernail size!
Printing out 1:1000 maps: A job for a web app. But likely a ToS violation, so it may not exist.
Map app

In a map app, when the 20 m scale bar is 20 mm long, that's buildings view. 1:1000. A meter looks a millimeter. With some extra work, you can also print them out at scale.

buildings view ------- 10 m
Papercraft Big Ben
Scaled to 1 meter per millimeter. 1:1000

This one is somewhat tattered after decades of use.


Original - not scaled.

In buildings view, you can imagine holding buildings in your hand. And small cities can fit in your room. But big cities...

Pink by Tbycolive
Walking on a model of NYC

Errata: It's 1:1200 scale. So for 1:1000, buildings should be 20% bigger.

A staircase at MIT
This is Barcelona, with 133 m blocks. Other floors have Mexico City, Beijing, and Boston.

real view

real view
millimeters in your hands

The real view you know, everything is it's real size.

How big is a slice pizza in real view? Mouth, err, hand-sized.

How big does a building look in real view?

view out the door

In the real-world real view,
a building looks like... well,
a building. :)

Credit: Dayspring Montessori School
While size can be taught without numbers, numbers might be made accessible surprisingly young. Especially with AR coming.

AR rulers

One of the first Apple AR ruler demos. (2017 June)

But once you 3D scan your room, measuring distance is just tapping. And scale-model classrooms become ambient, instead of a maybe-happens-once activity.

micro view

micro view
micrometers in your hands

If you imagine zooming things a thousand times bigger...

Fungus on a pumpkin

Photos by Pacific University Child Learning and Development Center.
Balls on a straw photo CC0 by me.

PacificU CLDC

These videos... illustrate some limitations of current microscopy UX and pedagogy.

Hand-held digital microscopy: Light conditioning, digital processing, and phone/tablet display, have made microscopy much more accessible that it was with stains and optical scopes. In the future, scale bars will hopefully become more common. Autofocus will help in Kindergarten. And SLAM (simultaneous localization and mapping) and AR display will change an exercise in isolated photography and photo interpretation, into simply seeing 3D things made bigger, increasing accessibility K-grad. You could scan a pumpkin with your microscope, like 3D scanning your home with a phone.

view out the door

How big does a real cup look in micro view?
As tall as a tall building.

nano view

nano view
nanometers in your hands

If you imagine zooming things a thousand thousand times bigger...

Bogus: While the DNA length and bending radius is plausible, it's shown in 2D. And so is too spread out.

As an example of the difficulty of creating content, one MIT student was distressed by the virus's head being broken off.

nano view ------- 10 nm
proteins atoms

Credit: Rocky Mountain Laboratories, NIAID, NIH

from Almost Unschoolers
E.coli bacteria garbage-bag tubes
And airborn bacteria hot-air trash-bag balloons.

from Almost Unschoolers

by ongissim on Instructables

Credits: beach, salt.
Table salt seen from a beach of atom sand
Nano view

Bogus: Real table salt would be whiter, and translucent, with sky tint showing through. And with the grain this dinged up, it would be like frosted glass - the buildings inside shouldn't be this sharp. But maybe it's a grain "ghost".

view out the door

How big does a hair look in nano view?
As wide as a short tall building.

atoms view

atoms view
picometers in your hands

If you imagine zooming things a thousand thousand thousand times bigger...

atoms view ------- 10 pm
Most videos of Walmart ball pits are unusably unsafe. Suggestions welcome.

by unknown
Walmart atoms
Climbing among atoms

Too big for atoms in a crystal, but ok for large free atoms.

What does a cold virus look like in atoms view?

A big round gym with atom balls inside? Err... need a better example.

nucleons view

nucleons view
femtometers in your hands

If you imagine zooming things a thousand thousand thousand thousand times bigger...

nucleons view ------- 10 fm
2010Neon nucleus

240Plutonium -> 100Zirconium + 140Xenon fission model
S.Umar 2010?2013?

How big does an electron wrapped around a proton look, in nucleons view?
It's rather larger than a football field. What would be a better analogy?

Football field big. The tiny proton is in the center, sitting on a blade of grass.

Size - misc

using other scales

Size - using other scales

We'll sometimes use other scales too. Scaling by 1000x steps is good for remembering, but not always good for play. For example, consider a bus. Two choices. Real size - which rather too big to play with. Or 1000x smaller... grain-of-rice size. Which might be ok for making a big parking lot, but... beware hurricane sneezes. So we'll sometimes use custom scales in between. When you use other scales, just remember what the thing looks like at some 1000x scale, to help you remember how it compares to other things. And when you can, draw a scale bar.

arms, hand, fingernail, tiny

arms, hand, fingernail, tiny

How big are toys? How can we say? We'll wave our hands! And describe them that way.

Arms, hand, fingernail, tiny.

Arms-sized, hand-sized, fingernail-sized, tiny-sized.



When I say measurement, perhaps you picture a person patiently peering at a ruler? But if your partner asks for a piece of paper for penmanship, and you are puzzled whether they would prefer a poster, a post-it note, a piece of tape, or a period-sized particle of paper, then a ruler isn't going to help. You first need to practice practical perspective. Appreciate approximation!

Sometimes you want things measured just right. Sometimes a factor of two will do. Or three, or ten, or more!

good enough precision

Let's talk about precision. What level of detail is needed? And when? What is insufficient, appropriate, excessive, and cluelessly insane overkill? What is good enough?

If someone asks you, "What time is it?" Answering "daytime" is usually insufficient. But answering "12 minutes and 34 seconds after the hour... beep" is often more than was needed.

If a friend asks you for a piece of paper to write a note on, what size paper do you give them? An arms-sized poster? A fingernail-sized torn-off corner? A tiny-sized bit of confetti? Or do you give them something hand-sized?

Sometimes you need a ruler. Sometimes you need to measure carefully. But often, waving your hands is good enough.

we make a lot of approximations

which fingernail?

which fingernail?
Calibrating your hands

Measuring length and area with Maps

Measuring length and area with Maps
Playing with real numbers. Drawn from diverse scales. And learning about the world at the same time.

Google Maps and Bing Maps let you measure length and area.

To measure area (on 2017-04, on desktop): Right click; select "Measure distance"; click on points; and finish by either clicking on the starting point (Google), or on "Close shape" (Bing).

Measuring area with Google Maps
A sidewalk cleaning contractor explains

Errata: "off by an inch or two [...] even a few square feet" is way too low. A 300 ft perimeter, with a 1/2 ft position uncertainty, is a 150 ft2 area uncertainty.

Measuring a football field rectangle with Google Maps
Length, perimeter, and area.

Roundabout links thanks to
Rotaries vs Roundabouts.
Measure area of a circle

Order of magnitude bounding: Is it more like 1 m2, 10 m2, 100 m2, 1000 m2, 10,000 m2, 100,000 m2? Can you suggest some upper or lower bounds? Were they hard (high-confidence) or soft bounds?

Fingers: If you zoom so a traffic lane is 1 finger wide, then how many fingers wide is the circle? About how many meters wide is a traffic lane? The circle? What's the area of a square that wide? The area and circumference of a circle is 3/4 the square that wraps it. What's the area of the circle?

Measure width: With the map's "Measure Distance" tool, measure the width of a circle. What's the area of square that big? Circle? Using πr2?

Measure area: With the tool, measure the area of an n-gon. Try 4, 5, 6, 8, 10 sides.

There are a lot of possible circles. Grass, first lane, etc. Measure and compare different circles.

Some rotaries have something in the center, like a statue. Is it really in the center? Measure radius vs diameter.

Then use the area for real. How much crop, seed, weedkiller? Time to walk, mow, harvest.

Traffic circles: Brookline, MA. Center-pivot irrigation circles: Finney County, Kansas, info. What else...?

Draw a circle on top of google maps. Regrettably, you can't use the "measure distance" tool on this one. :(

Is there some website with lots of map links for circles? Other shapes?

Community scale-model gold lattice

Community scale-model gold lattice

Sort of like a community scale-model solar system. But for atoms.

15 fm from 1.26*1971/3.
136 pm from Cordero Covalent radii revisited (2008).

Make gold nucleuses
Out of paper or play dough or cookies or meatballs or... any 15 mm ball.

nucleons view ------- 10 fm
197Au gold nucleus

Draw a gold atom lattice
In nucleons view, 135 meter radius circles, positioned in hexes

Here's one way to draw the circles. Use the search bar to find your community, then left-click draw, and right-click remove, to put down circles. In satellite view, putting circles on top of circles, makes them easier to see.

MIT, Harvard, NTU.

Next layer is 6-ish(?) floors up.

Caveat: Hmm, do I have the packing right here?

Stories - nuclei

What we don't and do know

What we don't and do know (2016)

We don't understand most of what the Universe is made of. Dark energy and dark matter. Oh, we know lots about it. Like an oddly-shaped unopened Xmass present we've spent a lot of time observing. We know lots of things it can't be. And have lots of guesses about what it might be. And some of those competing hypotheses currently seem better contenders than others. Many have been ruled out by what we've seen. But we don't know enough to choose among them, or maybe to realize we need a new one.

But there's a part of the Universe we understand somewhat better. The 100 billion stars in our galaxy. The gas and dust spread around them. And those in the 100 billions of other galaxies. The gas stretched between clusters of galaxies, like rivers of stretched taffy. These are all mostly made of neutrons and protons and electrons, gravity and light.

The stuff we don't understand, the dark energy and dark matter, are more spread out than familiar matter. They don't gravitationally clump as much. And space is really really big. So around here, locally, around Earth, and our solar system, they don't have much effect. So when you look at a bathroom scale, and see you are say 50 kilograms or 100 pounds, that is almost all neutrons and protons. With a tiny bit from electrons, and basically nothing from dark matter.

The stuff we're made of was born with the Universe, was fused together by stars (especially exploding ones), and sticks together like legos. We are made of star stuff. Let's talk about it.

Does "locally" include the galactic disk?

sticky little balls, jiggling

sticky little balls, jiggling
Atoms are little balls. With a littler little ball inside a bigger little ball.

Photo wanted: I saw the real version of this photo many years ago. It's a shape(spin?) isomer with a multi-hop decay, one of which is visible. So a nucleus was tweezed, stripped of all electrons, and bombarded to naked-eye visible florescence. It was likely the cover photo on something. It's only a diffraction dot, but then, so are nighttime stars. I've been trying to find it again for years. Any ideas?

Idea: The point is, nuclei are not weird abstractions. They're just little balls.

A single nucleus, glowing

An atomic nucleus is a very little ball. Most you can't see. But a couple, if you brightly shine gamma-rays on them, visibly glow green. Here's a picture of one, shining in the window of a vacuum vessel.

Bogus: This image is fake. There's a real one like it out there, but I'm having a hard time finding it. So this is a placeholder.

protons and neutrons are little balls.

nucleons view ------- 10 fm

They stick together to make nucleuses. So we call them nucleons.

nucleons view ------- 10 fm
11Hydrogen nucleus
2010Neon nucleus
Isolated protons are a sphere? But what about donut/peanut?
nucleons view ------- 10 fm
Miller 2003 src

"The proton instead exists as a mixture of many shapes." ""It's all these shapes at the same time,"" "Dr. Ji of Maryland said any directly measurable property, like the density of electric charge, would appear spherical." - NYT.

electrons are much bigger, but much lighter. Fluffy cloud.
Well, fluffy but hard - they can sure hurt when you stub your toe, or try to run through a wall.

atoms view ------- 10 pm
an electron stuck to 1 proton (Hydrogen)

Nucleons - creation

Creation of nucleons

Almost all nucleons were created a few minutes after the Big Bang. They've been flying around and clumping ever since.

[quark fog cooling condensing into droplets called nucleons]
[quark soup, err... fatty, cooling coagulating into little fat droplets?]
[are nucleon's virtual quarks similar to quark soup? enough to do a "soup condensed into droplets" story?]

Nucleons - converting

Converting between neutrons and protons

All alone, a proton will live forever.

All alone, a neutron will decay into a proton and an electron within a few hours.

100 n, 0 p, 0 e; 00:00 [restart]
Neutron decay
18 minute half-life, n -> p and e.

Charge conservation: p+1 + e-1 <=> n0. And 1 - 1 = 0. So you end up with the same total charge as you started with.

Mass conservation: 1p + 0e <=> 1n. A proton is very slightly lighter than a neutron. And an electron is very light. So you almost end up with as much mass as you started with. Almost - that little extra bit of energy is sometimes important, so we'll talk about it later.

[In a nucleus...] [decay] [blocking decay by stripping electrons]

Nucleons - destruction

Destruction of nucleons
Convervation of mass as counting marbles. Nucleons are very hard to create, and very hard to destroy, so you usually have as many as you started with.

Destroying nucleons is very hard.

[NS as big nuclei] [black holes] [LHC recreating Bang conditions] [spallation?] [...a few at a time] [baryon/mass conservation]


We name nucleuses by how many protons they have

We name nucleuses by how many protons they have.

Distinguish the physical thing, from human naming and models.

A nucleus with 1 proton is called 1Hydrogen, 2 protons is called 2Helium, 3 protons is 3Lithium. And so on. 6 protons is Carbon, 8 is Oxygen. 26 is Fe Iron, 53 is Iodine, 79 is Au Gold, and a nucleus with 92 protons is called Uranium.

Here's a periodic table with more names.

Why name by how many protons? Why not neutrons? Or the total number of nucleons? Well, protons hold and attract electrons. Electrons do chemistry. Humans are blobs of chemistry. Blobs that like 79Au gold and other materials. So humans care about proton counts.

Naming nuclei - symbols

Writing atom names as symbols

We name nucleuses by how many protons they have. But different languages often use different names.

Hydrogène? Wasserstoff? 氢?

So for each name, there is also a short nickname symbol, like H, He, Li, C, O, Fe, I, Au, and U.

The names can be different in different languages. But everyone everywhere uses the same symbols!


On Google Translate you can
click the right play icon
to hear how the words sound.
protons symbol  some names
1 H hydrogenen hydrogènege Wasserstoffdecn ...
2 He heliumen héliumfr Heliumdecn ...
3 Li lithiumen lithiumfr Lithiumdecn ...
... ...
6 C carbonen carbonefr Kohlenstoffdecn ...
7 N nitrogenen azotefr Stickstoffdecn ...
8 O oxygenen oxygènefr Sauerstoffdecn ...
... ...

When you see C, did you say to yourself "cee", or "carbon"? See if that changes as your read more...

Naming nuclei - numbers

Writing atom numbers

He 2He 3He Helium-3

Helium means a nucleus with 2 protons, and this number -> 2He also says 2 protons, so we usually don't write the number too. Unless you want to emphasize it. Because that would be saying the same thing twicetwice, which is usually sillysilly.

We sometimes write the total count of protons and neutrons in the top left corner. We name nucleuses by how many protons they have. And then put the total number of protons plus neutrons in the upper corner. Or after the name.

3He aka Helium-3 is 2 p (because He) and 1 n (because 3 - 2 = 1).
4He aka Helium-4 is 2 p (because He) and 2 n (because 4 - 2 = 2).

So, how many neutrons does 168Oxygen have?

How big are nucleuses?

How big are nucleuses?

Nucleuses are tiny and fingernail sized in nucleus view.

Quick and sloppy. Intended to be spherical integration of tumbled mass density. The small image sizes, and spherical integration, help to mask error. Max density thickness is normalized to black. Here this is done separately for each nucleus, making the total graphic somewhat bogus. 1H is (kludged?) from the proton mass curve in fixme. The rest are Woods-Saxon 1.26 A1/3 fm, a 0.7 fm - parameters from Schwierz, Wiedenhöver, Volya 2013. For A < 16O, with a kludged linear correction, using a 4He radius eyeballed from Schäfer 2015. Yuck. Ground state only. No exotic isotopes, halos. A rough draft.
nucleus view ------- 10 fm

Bogus: Nuclei lighter than 16O are kludged. 1H kludged separately.
Bogus: Black is set separately for each nucleus. But if 197Au is this dark then 12C should be and 1H hard to see


Motion blur

Motion blur

from "This Ain’t No Bokeh – Avoiding Motion Blur" by John Cornicello
by unknown. Seen here and here.
by Ebran, Khan, Niksic, Vretenar.

motion blurred Snap Cube spinner.

Regrettably most of these examples are changes in the object, not in the viewing reference frame.

nucleus view ------- 10 fm


Spinning figure skaters - play at 2x speed.

Are you going to get hit? To tell that, a tumbling spinning blurred picture is good. But to see the pieces, the dancer's two arms, or 8Beryllium's two 4Heliums, then you want look from a body-fixed frame.

A spinning cylinder
A spinning baseball
A spinning ball
Spinning selfie

The camera frame is fixed to the body.

Nucleus shape

What shapes are nucleuses?

Nucleuses are tumbling extremely fast, so usually we draw them with motion blur. But sometimes it's nice to see them unblurred, so we can see what's going on. Spinning selfies of nucleuses.

Space/lab vs body-fixed/intrinsic frame.
by Ebran, Khan, Niksic, Vretenar.
from Clustering in Light Nuclei; from the Stable to the Exotic by Martin Freer.
fixme from LANL
fixme from nature mumble

But why is Ebran Ne ground state blob-with-stick (fig 4), when Zhou et al fig 1, and old Ebran thesis?

Has anyone used Ikeda diagrams when teaching elements to kids?

by Martin Freer. Caution: energy in each column is separate. Could use reformatting.

Here is an interactive Z-N nuclear landscape. Others focus on nucleosyntesis, etc. Has anyone used a Z-N diagram coupled with a periodic table when introducing elements to kids?

nucleus view ------- 10 fm




100Zirconium and 140Xenon

208Pb lead


Errata: Some of these sizes are trash placeholders.

What is X mostly made of

What is X mostly made of

nucleus view ------- 10 fm

Big bang (minutes after)
Universe now
Solar system
Earth's crust

Seawater - water.



You - water, carbohydrates, and some proteins (made of amino acids, which have an N).



Sun making Helium

Sun making Helium
Sun at birth (now minus 4.6 billion years)


Sun now

[draft in]

+ + ->
4He + 4He + 4He -> 12C

+ ->
4He + 12C -> 16O

Making nucleuses

Making nucleuses

Bigger nuclei are made by smushing together smaller nuclei.

Created mostly by:
Cooling early Universe


Exploding stars

Most local mass is nucleons

Most mass around here is nucleons

Since nucleons are hard to create or destroy, [mass conservation]

weighing things is nucleon counting

weighing things is nucleon counting

A 2 kg box, or 4.4 lb box, is a more convenient way of saying 1027 nucleons.

sticky little balls, jiggling - three kinds of sticky

sticky little balls, jiggling - three kinds of sticky
  • gluons: nucleons are strongly glued by gluons
  • gravity: nucleons attract everything with weak gravity
  • electric charge:
    • protons and electrons attract and repel themselves electrostatically
    • protons and electrons bend their paths electromagnetically

Wait, isn't that four kinds of sticky? Well, kinda? But electrostatics and magnetism are the same thing seen from different perspectives.

sticky little balls, jiggling - nucleons are strongly glued by gluons

sticky little balls, jiggling - nucleons are strongly glued by gluons

Nucleons are made of quarks and gluons. The quarks are stuck together by gluons. Strong force. But nucleons next to each other get stuck too.

nucleons view ------- 10 fm
nucleon; residual strong force

here, stuck.
but here, the stickiness is too weak to even notice.

Gluon stickiness is very strong, but very short range.

Nucleons stick together by sort of the surface tackiness from the glue that holds each nucleon itself together.

sticky little balls, jiggling - nucleons attract everything with weak gravity

sticky little balls, jiggling - nucleons attract everything with weak gravity
nucleons view ------- 10 fm
proton mass density
neutron mass density

Gravity is very very weak. But very long range. And it adds up. Try jumping away from Earth. You got pulled back down, didn't you? An entire planet of nucleons is pulling on your nucleons. Each pull is tiny, but they added up, and pulled you down. You are stuck to Earth by gravity.

For gravity, electrons don't matter much. Electrons are a thousand times lighter than nucleons. And on Earth, for most every electron, there's a proton around somewhere, usually nearby.

Very very long range. Gravity sticks the Earth to the Sun, both to our Milky Way galaxy, and our galaxy to our galactic cluster, and our cluster to the local supercluster. You and I and everyone are being pulled towards our supercluster's Great Attractor. Other superclusters are attracted too, but are moving away too fast to be stuck.

sticky little balls, jiggling

sticky little balls, jiggling

Temperature is jiggling speed.

"The weather forecast for tomorrow is overnight lows of 400 meters per second nitrogen and oxygen, warming to 420 meters per second by early afternoon." - imaginary TV News weather person. FIXME

sticky little balls, jiggling - sticky vs jiggling

sticky little balls, jiggling - sticky vs jiggling

Which is stronger, sticky or jiggling?

Sticky things stay stuck if there's only a little jiggling, but get unstuck by more jiggling. How much jiggling? It depends on how strong the sticky is.

With a temperature of... (at room pressure), what does sticky vs jiggling give you?
1000,000,000,000 K 1012 K quark and gluon gas too jiggly for nucleuses or nucleons
100,000,000,000 K 1011 K Iron gas,
H and O gas,
Oxygen gas,
too jiggly for any nucleuses to keep any electrons
10,000,000,000 K 1010 K too jiggly for most nucleuses to keep any electrons
1000,000,000 K 109 K too jiggly for light nucleuses to keep any electrons
100,000,000 K 108 K too jiggly for nucleuses to keep outer electrons
10,000,000 K 107 K Iron gas H and O gas Oxygen gas too jiggly for atoms to stick together
1000,000 K 106 K H2O gas O2 oxygen gas
100,000 K 105 K
10,000 K 104 K too jiggly for liquids
1000 K 103 K Iron liquid too jiggly for solids
100 K 102 K Iron solid H2O solid Oxygen liquid ^- we live here
10 K 101 K Oxygen solid

The Universe started out very very jiggling. It's been cooling every since. First quark-gluon gas cooled stick together into nucleons and nucleuses. Then they cool enough to stick electrons. And then for those atoms to stick together.

Stars are still very jiggling. They can create oxygen nucleuses from smaller nucleuses. After they escape the star as oxygen plasma, they can cool enough to stick electrons, and become gas. FIXME Then they might stick to another oxygen, and become O2. Or stick to hydrogen, and become water gas. And maybe cool enough to become liquid. And maybe cool more, to become solid. And solid is the end - solid goes down to zero jiggle.

Little balls move in straight lines, until

Little balls move in straight lines, until

Little balls move in straight lines, until... something happens to them.

Teach Newtonian mechanics in micro, then do macro. To avoid conflict with naive understanding. In micro, things keep going, and energy loss can be discrete events. Transition to macro is a "where's the dissipation?" game. Why did the hammer and nail not keep going? Well, we talked about crumple zones and fracture, and look at the wood. And here's IR video - look how brightly hot the nail is. Slow vs fast pool tables - what parts of the table are doing the extra dissipating? (Johnny D's vs MIT CSAIL's tables.)

What can a little ball do, to stop going in a straight line?

  • get pulled by gravity, from nucleons or black holes or dark matter
  • get pulled or pushed by electromagnetism, from protons and electrons
  • hit something
  • throw something
Use random walks to teach "straight" until hit.

[cosmic ray bent random walks] [gas random walks]

Stories - atoms

Gold atom

Gold atom
Why the focus on gold? Availability of videos and micrographs goes Si,Au,misc. And gold is more hands-on familiar than silicon. I'd love to do Al,Cu, or Fe instead, but oh well. Perhaps introduce Si after C, as Carbon's sister element - one widely encountered, but rarely alone.

nucleus view ------- 10 fm


atoms view ------- 10 pm

Gold atoms

Gold atoms
Gold atoms

nano view ------- 10 nm

Gold atoms

nano view ------- 10 nm

Neck melts

nano view ------- 10 nm

Gold leaf
nano view ------- 10 nm
0.0001 millimeters
Making a wall of gold atoms

In atoms view, gold atoms are more like 12" balloons inflated to 11". And all the same size, so the crystal doesn't look squashed. To size balloons, you can use a cardboard box with a hole.

The right side of the bottom blue row has a dislocation.

Gold nanoparticles

Gold nanoparticles
Gold Nanoparticle - Sixty Symbols

nano view ------- 10 nm

Sigh: "ten to the blahdy blah means nothing" - as in, it's usually taught so badly, that most youtube listeners won't understand it. In science and engineering, we use these all - the - time.
"unimaginably small [...] 15 nanometers" - as in, most things are "unimaginable" when explained really badly, and size is usually taught really badly.

Nanoparticles coalescing

nano view ------- 10 nm

Nanoparticles coalescing

Best seen on fullscreen.

nano view ------- 10 nm

Nanoparticles coalescing

nano view ------- 10 nm

Gold tips touching

nano view ------- 10 nm

TODO: Mesoscale emergence of bulk properties: Eg, color vs particle size. ~30 um is gold color, but what about ~10 um and ~1 um?
Nanoparticles jiggled by water
Spots of laser light reflected from 15 nm gold nanoparticles, seen through a microscope. The particles are smaller than one pixel, but their bright reflected light is blurred bigger.

micro view ------- 10 um

The microscope video is about 166 nm/pixel and 640 pixels wide.

nano view ------- 10 nm
15 nm

Melting simulation

nano view ------- 10 nm

Bogus: Atoms are not yellow. And small nanoparticles of gold are not gold color.

Gold nanoshells for cancer therapy
Synthesis, and toasted chicken

Atoms flying around and bouncing

Atoms flying around and bouncing

A placeholder for an interactive I haven't written.

There's another video somewhere which includes a nice time counter, in seconds. So a long line of zeros, ticking away picoseconds at the end.

Air, a simulation excerpts, looped
Shown in slow slow slooooowwwwww motion

nano view ------- 10 nm

original on youtube.

Breathing the world

Breathing the world

Inhale. Exhale.

One breath


Breath in a room
Sharing air with your neighbors.

If you are sitting in a classroom, you are breathing air and water that other people just had in their lungs!

Trees of air and sunlight

In a tree: sunlight + CO2 + fertilizer -> wood + O2. In a campfire: wood + O2 -> light'n'heat + CO2 + ash. You get back what you put in, but the light is weaker.

Breath becomes your

[stats for one breath][timing diffusion/circulation/latency][cell/molecular-level impact]

Sharing widely

As you watch a sunset, you breath some atoms exhaled by each human who has ever watched a sunset.

As you read this page, you will breath atoms breathed by Franklin when he read the final draft of the Declaration of Independence for the first time.

As you head out the door, you share breath with a fur-clad traveler leaving home in Europe 10 thousand years ago. As you drive to work, with his struggles across the Alps. As you return home, with his/her return.

A few deep breaths get you atoms from your mother giving birth, from yourself taking your first breaths, and from... a Caesar's last breath (the common name of this observation).

Are you grossed out by inhaling air others have exhaled?

Think of something people do that grosses you out. Now inhale. You just breathed atoms that were exhaled by every single person who ever did that thing, and every single time was done, ever (before about 2007, to give the atmosphere a decade to mix). And you are about to inhale again? How's that for gross?

And every cow, elephant, pig, horse, whale, dolphin, lion, tiger, bear, human, hominid, primate, T-Rex, giant sloth, ....
Caesar's last breath

The basic idea is, once you give the atmosphere time to mix, each breath does a random draw of atoms, giving odds that any particular previous breath has some atom in common.

Your breath is about a liter of air, and thus about 1022 atoms. The atmosphere is about 1044 atoms. The breath's atoms will be well mixed back into the atmosphere after something like 10 years. Then, any randomly selected atmospheric atom has about a 10-22 chance (1022/1044) of being from the your breath. Suppose you take another breath, again of 1022 atoms. You can expect something like one of them, on average, to be from your first breath when you were born. The exact number will vary. It is not a direct hop from one breath to the next - the atom may have been breathed by others (or by yourself), in between the two breaths.

Hydrogen - diatomic

nano view ------- 10 nm
10x nano view ------- 1 nm

Bogus: I'm currently just overlaying two electron densities, as if they were still isolated. In between them, it should be a bit darker.

atoms view ------- 10 pm

Reading atoms on an STM image

Reading atoms on an STM image
Reading atoms on an STM image
nano view ------- 10 nm
10x nano view ------- 1 nm

105Boron, 126Carbon, 147Nitrogen, 168Oxygen.

Animation made with STM

Animation made with STM
nano view ------- 10 nm
10x nano view ------- 100 nm

Size from WP... with a 10x correction.

CO (Carbon monoxide) molecules on a Cu Copper plate. The ripples are electron wackiness.

Why no jiggling? It's cooled to something like 10 K.

The STM tip scans to make an image. And then, moved closer, is used to drag around atoms, one by one, to make the next frame.

Moving Atoms: Making The World's Smallest Movie

The IBM page has more videos, but a buggy player. :/

Try to defuse the "boyness" of the video title.

About the title - "A Boy/Girl And His/Her X" is a trope.

AFM - Atomic Force Microscope

AFM - Atomic Force Microscope
real view ------- 10 mm

Errors: Hairs are usually 100 um and less, not twice that. In the animation of a tip moving up and down over "atoms" - those balls look like ~3 um calibration balls (10000x bigger than atoms). Caution: The dust mite is shown at a different scale than the tip. A dust mite is several 100 um. The tip is compared to "the poo of" a dust mite.

The whole video 5:30 is a nice introduction, but it reinforces the "white coat" misconception. Many folks have their AFM just sitting on an office table, like an regular optical microscope.

AFM tip working
and zoom back to see the cantilever
micro view ------- 10 um
Lego model of an AFM

Other AFM models: blah, blah, blah.



I long ago saw a nice youtube video of an ab initio water electron density simulation. But I'm failing to find it. :( Better than these is needed.

blah, blah, blah, blah. Also blah.


water ice structure and melting
water freezing
nano view ------- 10 nm

water vaporizing
nano view ------- 10 nm

Drying your hair in space

Drying your hair in space

A gas model, using ball bearings

A gas model, using ball bearings

Jiggled by water

Jiggling things jiggled by jiggling water
A protein jiggled by water jiggling
nano view ------- 10 nm

0.5 nanosecond per second slowmo. 310 K. Protein is 1STN, a bacteria nuclease.

Protein strings jiggled apart
by increasingly hot/jiggling water
nano view ------- 10 nm

That's part of why we cook food - to jiggle apart bacteria proteins.

Nanoparticles jiggled by water
Spots of laser light reflected from 15 nm gold nanoparticles, seen through a microscope. The particles are smaller than one pixel, but their bright reflected light is blurred bigger.

micro view ------- 10 um

The microscope video is about 166 nm/pixel and 640 pixels wide.

nano view ------- 10 nm
15 nm

Stories - density


How many nucleons in a 10 nm cube?
nano view ------- 10 nm
atoms nucleons/(10 nm)3 kg/m3
water X 1H2
X 16O
X 27Al
X 196Au

Floating on a gas

Floating on a gas

Floating on SF6 videos: another; big foil boat; Mythbusters fail; balloon.

Floating on SF6 sodium hexafloride gas
Aluminum foil boat
Bubbles floating on CO2 carbon dioxide
from a drink

CC BY-SA Anders Finn Jørgensen

CC0 by unknown
Floating on hard-to-see water

These are floating on a liquid, not a gas. But they show that floating on things that are hard to see, isn't so very strange.

Separation using density

Separation using density

Use application examples: Industrial process videos; diy and hands-on examples; traditional and historical examples.

Bogus: Several of these videos aren't quite density separation. They're drag/mass separation, which unlike density, is shape dependent. And shape is involved with some common density misconceptions. So if done for real, this would have to be handled less sloppily.

Gold panning

Caution: He uses "heavy" to mean dense, not massive.

Gravity separator
For grain, lentils, peanuts, etc
Seed cleaning
Seed cleaning
Plastic cleaning for recycling
Seed cleaning

Japanese macaques separate wheat (floats) from sand (sinks). And wash potatoes and vegetables.

Air sloshing around in a car

Air sloshing around in a car
Balloons in a turning car

green balloon with He, red with air

Balloons in an accelerating/breaking car

another He


Water sloshing around in a moving tank

Water sloshing around in a moving tank
Slam! - nucleons keep going until they're stopped.

Making layered drinks

Making layered drinks

Denser stuff sinks. Less dense, floats. Sugar water density: how much sugar is dissolved? More sugar, is denser.

It's hard to find good videos.
Layers: juices; sodas; colored sugar water, skittles.
Avoiding mixing while adding: ice, spoon, syringe, dropper, dripper plate thing.

How to make a layered drink
From drinks carrying different amounts of sugar
Cans of sugar water

Planets are layered puddles

Planets are layered puddles

Planets are layered puddles. Less-dense layers floating on denser layers. And each layer is layered too.

layer density at top
density at bottom
stratosphere air 10-6 kg/m3
0.3 kg/m3
troposphere air 0.3 kg/m3
1.3 kg/m3
frozen water 917 kg/m3
fresh water 1000 kg/m3
ocean water 1025 kg/m3
1028 kg/m3
crust 2200 kg/m3
2900 kg/m3
. .
. .
upper mantle 3400 kg/m3
4400 kg/m3
. .
. .
lower mantle 4400 kg/m3
5600 kg/m3
. .
. .
outer core 9900 kg/m3
12200 kg/m3
. .
. .
inner core 12800 kg/m3
13100 kg/m3
. .
. .

These colors are completely bogus.

Planets splash

Planets splash
Planets are layered puddles. When hit, they splash.
Moon formation - blah
Moon formation - blah

K-T impact - blah

An imaginary impact

planets view ------- 10 Mm

Density of stuff

Density of stuff
stuff density
hot ISM 1 nucleon/m3
warm ISM 103×0.4 nucleons/m3
cold ISM 104×0.4 nucleons/m3
1AU solar wind 104×0.9 nucleons/m3 9 nucleons/cm3 [1]
STP H2ydrogen 0.1 kg/m3 1026×0.5 nucleons/m3
STP Helium 0.2 kg/m3 1026×1.0 nucleons/m3
STP N2itrogen 1.3 kg/m3 1027×0.9 nucleons/m3
cylinder of N2itrogen 170 kg/m3 1029×1.0 nucleons/m3 [2]
liquid N2itrogen 810 kg/m3 1030×0.5 nucleons/m3 [3]
4°C water 1000 kg/m3 1030×0.6 nucleons/m3
Pb Lead 11000 kg/m3 1031×0.7 nucleons/m3
neutronium 1017×4 kg/m3 1044×2.4 nucleons/m3

[1] What's the solar wind like now, hitting Earth? Here's the current weather. Density is the third graph.

[2] Most cylinders of nitrogen compressed gas are around 14 MPa (2000 psi), so about 100x denser than STP. You can get them at large general stores (like Walmart) for beer (Guinness), and at gas suppliers for welding. A small 10 L (0.01 m3) tank holds about 2 m3 (60 cf) of STP gas. The nitrogen itself weighs 1.7 kg, and the tank weighs FIXME.

[3] Liquid nitrogen costs around $2 per gallon in dewars. You can quickly freeze ice cream with it.

Density of solar wind hitting Earth now
Current space weather

"Magnetic Field & Solar Wind Electron Proton Alpha Monitor (SWEPAM)", Duration: [7 days]. It's protons/cm3.

Caution: Saying "Density (/cm3)" instead of "Density (p/cm3)" is not good practice.

Cylinders of compressed gas

Cylinders of compressed gas
Real-world how-to's. Here, compressed gas, cylinders, He.

"Helium and a little of what you need to know as a balloon professional Part 1"
Helium vs balloon gas (He + air) - respiratory safety difference.

Additional context


Exploring in conversation with a master: The Vatican’s Latinist nurtured a renewed interest in Latin, and for a new way of teaching it. A new learning progression, new pedagogy, new text, a pursuasive teaching cohort, adoption, and institutionalization. But while those are nice, they are not the awesome bit. That was aparently walking in conversation with him through Rome, with the rich tapestry of a millennia of history woven through the environment.

"For decades, he had the power to change lives like no other teacher in our field. I saw him for an hour in Rome in 1985 and that one hour completely changed my life. His approach was completely different from every other Latin teacher out there, and it was totally transformative."

"He is not just the best Latin teacher I’ve ever seen, he’s simply the best teacher I’ve ever seen. Studying Latin with the Pope’s apostolic secretary, for whom the language is alive, using the city of Rome as a classroom . . . it changed my whole outlook on life, really."

"Seeing Rome with Reginald Foster is somewhat like hearing music for the first time. The city is threaded with a vast web of Latin inscriptions. They line the cornices of buildings, the base of statues and monuments, the tops of fountains and gates. The biographies of tens of thousands of dead souls are carved onto tombs and sarcofagi. They provide a running commentary on all you see, although virtually all of Rome’s three million inhabitants walk by without noticing them. To see Rome without having access to this Latin subtext is like going to the opera without a libretto—you can love the music, the singing, and the spectacle but you miss a lot of the drama."

Science and engineering are similarly a rich web of stories, woven through absolutely everything we see and touch every day. Similarly unnoticed. We've been having a bit of institutional difficulty gathering, crafting, and telling those stories. It seems worth remembering that if we can do it well, the payoff could be very big.

On adapting to interest: There's old advice for learning history: start with whatever you are interested in. Food, textiles, architecture, materials, games, environment, governance, whatever. Because it's all tied together, richly interconnected. So it doesn't matter where you start, which thread you start out following. What would it take to teach science like that?

There's an art project where you sit down, and watch an interesting video. But the reason it's interesting, is because an eye tracker is observing you interests. The video is like an old "choose your own adventure" story. If you are interested in some character, then the story emphasizes that character. And note that in support of VR/AR, eye tracking appears likely to become increasingly commonplace over the next couple of years.

Conversational systems: When standing with someone watching the IBM atom video, they often ask "what are those ripples?". But it's hard to detect and leverage that interest with only a web page. With VR/AR eye tracking (2018-ish) and spoken dialog systems (now-ish), we should be able to do attention/interest observation and optimization.

Hitchhiking the VR/AR selective sweep: During "beginnings", there are sometimes opportunities for impact/cost that are not available later. Opportunities to piggyback a change on the transition. Opportunties to establish new norms. Opportunities to help things happen a couple of years earlier than they might otherwise. So what, if anything, might be worth trying to piggyback on the transition to VR/AR?

For silly example, astronomy graduate students and educational content, pervasively get the color of the Sun wrong. It's been a "we should fix this - it's embarassing for the field" for decades. But the incentives just don't line up. Currently, there are only a handful of astronomy VR apps. A bit of focused effort might correct their colors. And perhaps establish a new normal, where new apps feel pressure to get it right, to not be the odd-one-out that's still getting it wrong.

Maybe. Or maybe Pearson et al will just dump large quantities of the usual brokeness, and any such effect will be swamped.

Or consider 3D biology videos which reinforce the "big empty body/vessel/cell" misconception. Or 3D molecular biology videos which ignore jiggling. These are in part rooted in technological limitations. But the absence of a moment of "here's reality", and a fade to usual, is a "we're not embarassed by this" social issue. One could briefly show a blood vessel packed full of red blood cells, before a fade to the usual "big empty vessel with a few cells floating by". Or briefly show blurred molecules slamming around, before the usual "molecules docking like spaceships". Or a towed vacuole, blurred to be everywhere with reach of the tether, before the usual "stately towed cruse ship". Changing the "we're not embarassed by this" norm seems infeasible. But establishing enough awareness, that comments are "it's beautiful, but", might perhaps be feasible? Or at least establish snarky comments about correctness as a thing? Maybe?

Some changes will "just happen", without dedicated effort. VR/AR will inevitably emphasize physicality and reduce abstraction. Dialog systems will become common (eventually). But what about "let's teach biology more quantitatively"? People have been saying that for years. Physicallity will help, but perhaps there's an opportunity to nudge. Or "let's do more rough quantitative reasoning". Or... what else? Any thoughts, on candidates, or on plausibility? Is there anything which won't "just happen" which seems worth pushing on?

VR/AR and teaching scale: Beyond 1000x chunking: CosmicView/PowersOfTen-like books/vidoes/interactives can show only 3-ish orders of magnitude at a time, from pixel to page. Users lose context, and retention is poor. Involving the room provides another 1-ish oom. VR/AR adds another 2-ish oom, at least as angular resolution improves. There are various ways to apply these to the size of things. Here, we have tiled size with 1000x chunks, and there are other possibilities. But we've been stuck with unfortunate tradeoffs, among memorability, inconveniently sized objects, and numeracy. VR/AR permits a larger context. Permits standing in nano view, seeing simultaneously sub-millimeter scale atoms, and a grain of table salt towering over the local city's skyline. Which permits revisiting the tradeoffs. It's been clear for two decades that 1000x chunking was only a placeholder until we got VR. We're almost there now. I wrote a usable WebVR stack last year, and official ones should be usable this year (2017). So what might we do with it?

Lack of evidence: Aside from a random NSF handout many years ago, as far as I know, teaching classes with 1000x chunking has nowhere been done or tested. And while there have been suggestions that teaching scale is critically important to teaching science, since at least the mid-20th century, we still do it very poorly. And as far as I know, it's never been a curriculum theme beyond a few isolated courses. So its benefits and tractability remain quite speculative.

Customizable zoomer: An interactive PowersOfTen-ish zoomer can help with telling multiscale stories. Here's an old ui test. Back in 2014, I started but didn't finish, a customizable zoomer - so one could create topical zooms, mixing google maps, JSMol molecules, images and videos of whatever physical width. For instance, a Mars transfer orbit, Earth photo, Bing maps down to an MIT lab building, picture of a grad student holding cubesat, cubesat, ion thruster chip, micrographs of chip tips, molecular simulation video, molecules in JSMol. The web tech was painful at the time, and browsers were buggy, but it should be almost trivial now. Perhaps it's time for a reprise, as no one else seems to be getting around to it. Perhaps also a WebVR version.

Hazen's mineral evolution: Mineral types vs deep time. Started as a framework for intro mineralogy, but became a NOVA episode etc. Slides (2016); site; first paper. Some years ago, he had encountered some interest in using it middle school, but I haven't checked back since.

Sphere packing: A neglected multiscale core theme. Atoms, proteins, viruses, nanoparticles, cells, material grains, soils, sand, agricultural products, gravel, sintering, sugar, foams, bubbles, spherical cows, and more.

Use the wrongness: Getting things wrong is pervasive in science education videos, journalism, texts, literature, and research. Why not treat it as a resource? For common misconceptions, show clips of it being taught, and ask "what is wrong here?" For "science experiments", what are some of the many possible confounds being ignored? For jiggle-free molecular animations, what would it really look like? When a non-blinded teacher video demo is bungled, and the result is then quietly falsified to match expectation, use it to discuss the temptations of scientific misconduct. When reading a nice chemistry education research paper, describing the incoherence of common content, then parrots a misconception from a nearby subfield, instead of being depressed, capture it as content.

Why aim young?: It's a useful writing discipline, like ELI5 ("Explain Like I'm Five"), encouraging the pursuit of clarity. Early primary has different constraints. I repeatedly hear variations on 'intriguing... but the <upcoming high-stakes exam: MCAS for med school, AP for college, etc> requires only <mindless version of X>, and I'd be doing my students a disservice if I didn't focus on that.' Amortization. Taught early, there's more time for avoided misconceptions to pay back the cost of the teaching. The potential upside is greater... How big is a red blood cell? At least some graduate students, first-tier medical school students, have no more clue than "really really small". But at least some early-primary students, have managed something vaguely like "about 10 micrometers! Because if you imagine zooming a tiny letter "a" to arms-sized, then red blood cells look like red M&M's - fingernail sized!". So imagine a cohort of such early-primary students. Just how awesome could their upcoming decade of pre-college science education be?

I'm not suggesting this is a worthwhile way to spend early primary time. That's an experimental question way outside my expertise. Merely that it might perhaps be less bad than some similar ways it's currently spent. Or at least, that some of it seems interestingly different.



Teach nucleons to kids!?! Absurd! How could you teach pions to kids? Or Hartree–Fock! Or quantum blah: Discussed at page top.

Why bother teaching atoms anyway? Orbitals and such. I've never needed them. Instead, teach communication/inquiry/blah: This question comes up in adult street usability testing. (1) If it's going to be taught, it might as well be taught less wretchedly. (2) The sciences and engineering are a richly interconnected tapestry - they're just never taught that way. If they were, you'd likely have found them of more use. Transferability, usability, hasn't been a priority.

OAQ ("once asked questions")

What about understanding as easily moving among multiple models (as in physics) - is this like that? Yes, and no. Mostly yes in the real physics sense. It's part of expertise. But not so much in the education sense of "we've taught you some unusable models, so we're done now".

Rough quantitative understanding: I'd like an unusually intensive emphasis on quantitative description and rough quantitative understanding, with its modeling, approximation, and estimation (regrettably not well illustrated by this page).

Describe physical objects tangibly: is in some sense a model. As are the stories and graphics.

Care in moving among models: Education content needs to be more careful than say informal physics conversations. An MIT biology professor used to draw "identical" circles on the lecture board. Sometimes they represented a cell, sometimes a petri dish, and sometimes an organelle, or a protein. Sometimes the meaning changed. And thus they were repeatedly a source of student confusion.

But educational model use is often profoundly dysfunctional.

The map is not the territory, and the model is not the object.

And scope of applicability is often not taught. Witness such classics as "apply the ideal gas law, to these numbers describing solid Argon". And one rarely sees questions of the form "here a physical situation; describe which models you're going to use, why they're a valid choice, and bound the associated errors". Plug-and-chug isn't success.

And the choice of models often seems a barrier to understanding. Incoherence obscuring what might be described more accessibly, less abstractly. Claims of "thing is too abstract for students in grade X" often seem to unpack as "we tried teaching it really, really badly... and wow, that didn't work... so obviously, the children are not developmentally ready for the topic".

So yes, I'd like to see qualitative and rough quantitative model use as part of scientific discorse whenever estimation is taught. Which is currently down to K, with some attempts at preK. But it has to be real, not education-style model use.

Though I wonder, as I often do, is it really just a K-13 problem? For example, yes, some best-practices videos for K-4 estimation are facepalm bad ("estimate the number of jelly beans in the jar... by looking at the jar... just look, and [magically?] write down a number"). But there have also been decades of complaints by physics/geology/other professors about PhD candidates not having a quantitative feel for the field. (Eg: What's a Newton-meter of torque? (reopening a soda bottle)). So, as with teaching size, I wonder if approximation and model use has problems K-grad. And perhaps, might also be improved by attempting better K-4.

How's that for a long and crufty answer?


As this page developed a density theme, some bits no longer fit. A few seemed worth including anyway.

Making ice cream with liquid nitrogen

Making ice cream with liquid nitrogen

Use real-world examples. Liquid nitrogen isn't something esoteric - it's sort of burger-flipping for ice cream.
(can skip the slow middle)

Dragon's Breath

Dragon's Breath
Food frozen in liquid nitrogen
How to handle safety is a puzzle. The waitress here one-handedly carries a tray of LN2 in cups. Which is perhaps less dangerous than hot coffee, but not good lab practice. There's a tradeoff between modeling real lab safety, vs "everyday thing, no big deal". Even while avoiding "lab coat and goggles" education safety theater. And then there's OSHA-like "it's not really needed in this case, but do it anyway to maintain good habits". So what should the objective function be?

Making of (but didn't like).


An example of a simple multi-scale story. A port of my old "Burst!" page. It was designed with very short clips, for child-like replay,replay,replay. But Youtube has changed it's UI since - replay now shows the entire video, not just the clip. So the UX is broken. Perhaps I could add an external [replay clip] button...

Things of different sizes, all bursting. From big science balloons, to viruses.

Large NASA scientific balloons

NASA photo
NASA photo
superpressure balloon
Weather balloons

Camera goes up - pop - parachutes down.


Pretty puff of dust.




Bursts like a soda can.




Hydraulic hose for construction vehicles

"Bang!" coming. Then construction.

Frozen can

This is why: you avoid wrapping your hand around a frozen can.

Party balloons

Burst like weather balloons.


Oil weakens latex, causing latex balloon-like things to burst.

Food bag


Eggs explode in microwave.

This is why: you microwave eggs either under water, or without their shells.

This is why: eye protection. Reminder: it could have burst at any time, like when put on the counter.


Popcorn foam.

Big cells

White blood cells. Red blood cells are hard to see once they pop.

A cell from a pond.


Bacteria are pressurized.

A bacteria is a bag in a ball - the cell membrane and the cell wall. The bag is pressurized (like 3 to 25 atm - like a soda bottle), and the wall keeps if from bursting. The wall is continually being renovated - torn apart and rebuilt. Many antibiotic drugs work by interfering with the renovation. If rebuilding slows, the wall weakens, and the bacteria bursts.

A bacteria also pops after being hijacked by a bacteriophage virus. It makes something like a hundred new viruses, and then makes lysin, and pops.

Errata: The video description (2015-Dec) on YouTube is wrong: penicillin doesn't increase the pressure, it weakens the wall.


Hard on the outside, stringy on the inside.

Viruses are hollow balls. Hollow balls stuffed with string. RNA or DNA string. To hijack cells, some viruses inject their string, others sneak inside and break open.

Bacteriophages are DNA viruses that attack bacteria by injection. Their balls are high pressure (like 50 atm - 10x more than a soda bottle, but 3x less than a SCUBA or welding tank). Often the balls burst before they get a chance to inject anything.

Cartoon of loading a bacteriophage DNA virus. Real molecules jiggle a lot - that's not shown.

I didn't find a burst video. ☹ Here is a picture.

If the virus ball has an injection stick, sometimes it breaks off. Or the ball bursts. From this paper by De Paepe and Taddei.

Here are cartoons of someone using a tiny bead to poke, tear, and crush empty virus balls. And heat to melt one. These are small balls of the kind that fall-apart. Not a burst, but fun.




melt. The ball itself is made of protein strings. Heat them, and they unclump. That's part of why we cook food.

What else bursts? Some magma chambers and volcanoes. Molecular cages, assembling and disassembling. What are your favorites? What is like bursting, but kind of different?

Thank you for your interest and feedback -- Mitchell Charity

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