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Here’s a meme stolen borrowed from a young-Earth creationist:

tennis ball.jpg

First of all, why are so many creationists these days becoming flat-Earthers?

But secondly, does this meme even make sense to you?  I can understand (sort of) the confusion that a spinning tennis ball might bring: water is flung off the ball, rather easily, so why isn’t ocean water flung off the earth?  That’s a valid physics question.  But what in the name of Odin does this have to do with gravity?

Let’s do the physics.  Suppose there’s 0.25 kg of water on the ball to begin with (corresponding to roughly ½ cup).  The radius of a tennis ball is about 6.0 cm = 0.06 m.  The rotation rate of a served tennis ball is typically around 2200 rpm = 230 rad/s.  Therefore the linear velocity on the ball’s surface is v = ωr = 230 (0.06) = 13.8 m/s.  So the force needed to keep the water on the ball (i.e. to make it move in a circle contrary to Newton’s 1st Law) is F = mv2/r = 0.25 (13.8)2 / 0.06 = 794 N, which is about 178 pounds of force.  It’s not surprising the water is flung off: what force is there that could possibly do the trick?  The water would have to be “stuck” to the ball with a force of at least 794 N in order to stay in place.  (Gravity won’t do: the force of gravity between ½ cup of water and a tennis ball is easily found to be 2.7 x 10–10 N, which is basically zero.)

OK, so what about water on the Earth?  The Earth is spinning, too.  Shouldn’t any water on the Earth’s surface be flung off?

Suppose I have half a cup of water on my desk.  Its mass is the same as in the previous example, but the radius of its motion is much bigger: 6,370,000 m, the radius of the Earth.  (I’m assuming for simplicity’s sake that I’m at the equator.)  Now, the half cup of water’s rotation rate is 1 revolution every 24 hours, or a rotational velocity of ω = 7.27 x 10–5 rad/s.  Even though this is pretty small, we still get a fairly large v = ωr = 463 m/s.  That’s your (linear) velocity at the equator, and it’s pretty big.  So far, it still seems plausible that water might be flung off.

But wait:  how much force is needed to prevent this?  Well, F = mv2/r = 0.25 (463)2 / 6,370,000 = 0.008 N, corresponding to the weight of less than a gram of mass.  Therefore, to not be flung off the Earth, a half cup of water needs only 0.008 N of force to be held in place.  Even without gravity, a tiny dab of scotch tape would be sufficient.  But there is gravity.  And in fact, gravity supplies a force of F = mg = .25 (9.8) = 2.45 N, or more than half a pound.

Seeing water flung off a tennis ball, it’s natural to wonder why water doesn’t get flung off a spinning Earth.  After all, we’re all moving pretty darn fast on this ride.  But the Earth’s radius is huge, so the force of gravity is more than adequate to keep things in place.  The fact that water is not flung off doesn’t mean gravity is a hoax, it means gravity is doing its fucking job.  The cure for this flat Earth bullshit is to take a basic physics class.

You fucking morons.

Image resultLeBron James will sign with the Golden State Warriors, “sources” hinted at Tuesday.

“This will be a new chapter in the legend that is my life,” James is alleged to have maybe said.  He announced his intentions in an unsubstantiated tweet at 12:02 AM Tuesday, just minutes after his Cleveland Cavaliers fell to the Warriors in the NBA finals.

The tweet said, “Joining the bandwagon!  I need another ring!!!”

James is expected to sign a one-year, $177 million dollar contract.  When asked if Golden State could possibly afford such an amount, James shrugged and said, “Maybe they’ll cut Patrick McCaw or something.”

James said he was switching teams for “personal growth” reasons:  “I need to go in a new direction,” James wrote in an alleged email to someone.  “I need an opportunity to expand my horizons.  And the only way for me to grow as a human being is to have another giant ring on my finger.  Three just isn’t enough.”

James thanked Cleveland in an off-hand way.  “I’m glad to have played here in Toledo, um, I mean, Cleveland.  Or wherever it is that I am.  But I’d love to move to Golden State…that’s in Wyoming, right?”

James will join Stephen Curry, Kevin Durant, Klay Thompson, and Draymond Green, who already play for the Warriors, along with Chris Paul, Kawhi Leonard, Isaiah Thomas, and James Harden, who are all expected to sign with the Warriors soon.

“We all need rings,” James said.  “That’s the only thing that’s important.”

Here’s another Oulipo poem for you.  Can you determine its unusual construction?

Come eat!

There is hay.

Net says, “red dice”;

Dude hesitate, kills mate.

He pagan, I paid.

Without sin, leer to read!

Image result for tower of babel

Here’s a new kind of art.  The artist (me?) writes a set of instructions for the reader to follow.  Then, to “experience” the art, the reader has to follow the instructions explicitly.  No fair cheating: you can’t really appreciate the artist’s “vision” unless you go all-in and do whatever the instructions say.

I hereby stipulate a few house rules.  I won’t ask anyone to do anything illegal (don’t want any lawsuits, here!).  I’ll also never ask you to harm yourself or others.  Finally, I will try to make these “poems” within reach of the average person…most can be experienced without any undo tribulations.

So here goes:

In Springtime

  1. Before dawn, hike by yourself to a suitable place to watch the sunrise.
  2. About five minutes before the sun crests the horizon, begin listening to Siegfried’s Funeral Music from Wagner’s Götterdämmerung.
  3. Listen to the music in its entirety.
  4. Count how many wild flowers you pass on the hike back home.

Image result for sunrise mountains

Adversity

  1. Wait for a moderately rainy day.
  2. Stand outside in the rain for ten minutes.
  3. Come back inside, change into dry clothes, and have a glass of pomegranate juice.
  4. Slap yourself gently across the face, and laugh, as I am laughing now.

Image result for rainy day

On Nature

  1. With pencil and paper, compose a haiku on the theme of nature’s beauty.
  2. Burn the haiku with flame drawn from a wooden match.
  3. With pencil and paper, compose a haiku on the theme of nature’s indifference.

Image result for chinese painting

The Human Condition

  1. At the grocery store, try to spend exactly five dollars, including tax, on things you don’t really need.
  2. At the register, note how many cents away from five dollars you were.
  3. Multiply this number by 100. For example, if you paid $4.83, you were $0.17 off, so multiplied by 100 this becomes $17.00.
  4. Go online and donate this amount to a charity of your choice.
  5. Enjoy your approximately five dollars’ worth of junk.

Image result for dali tuna fishing

Unrequited Love

  1. Go outside and wait until you see and can identify a wild bird.
  2. Go to Wikipedia and learn something new about this kind of bird—something you didn’t know before.
  3. Share this newfound knowledge with someone you love.
  4. Also share this quote: “If a lion could speak, we could not understand him.”
  5. Refrain from explaining yourself.

Image result for cedar waxwing

Wake Up

  1. Play a musical instrument for five minutes. If you don’t play a musical instrument, then sing a song instead.
  2. Stop playing or singing, even if the music isn’t over.
  3. The music’s over.
  4. Crack you knuckles and close your eyes.
  5. Think of this: there are as many stars in the universe, as grains of sand on Earth.
  6. Open your eyes.
  7. Now open your eyes.

Image result for milky way galaxy

Let’s watch a clip from the movie Superman II, which I saw in the theater in 1980:

Great acting, right?

From the time (Δt) that the kid is in the air, we can determine how high Niagara Falls (ostensibly) is.  I get Δt = 27 s, so the height of Niagara Falls is given by

H = ½ a Δt2 = ½ (9.8) 272 = 3572 m.

Wow!  That’s big…more than 3.5 km.  That’s over two miles high!

(It’s actually higher than this, if we notice that Superman didn’t even catch the kid at the very bottom.)

In point of fact Niagara Falls is 51 m high.  Only half a football field.  In the real world, it would take the kid (neglecting air resistance) all of 3.2 seconds to hit the rocks below.  Superman has no time to change his costume; Lois has no time to scream for help.  3.2 seconds, then splat.

Let’s ponder the magnitude of the error the filmmakers made here.

MOVIE: 3572 m

REALITY: 51 m

This is a 7000% error.  That has to be some sort of record.

To put it into perspective, it would be like listing Shaquille O’Neal’s height as 165 yards, instead of 7’1″.  This is fun!  In the world of Superman II, Oslo has a population of 43 million, Gone With the Wind has a running time of almost 12 days, the moon is almost as massive as the Earth, and the average cat weighs 630 lbs.

The movie supposedly grossed $190,000,000.  We now know, however, that (given the 7000% inflation trend in Superman II) the move only grossed $2,700,000.

This makes Superman II the greatest flop of all time.  For some reason, though, when I saw it around my 12th birthday, I liked it.  Maybe that’s because it was really my 840th birthday?

All the ways—

What scares you more: that I will talk of death, and injustice, and spiritual annihilation?  Or that I will explain how the equation

Pfi  = ∑ Γ(S)

affects your life?

Admit it.  You want death.  You want injustice.

You want spiritual annihilation.

I get it, I get it.  Math is an annoyance; math is anathema.  As it did for the learn’d astronomer, math makes you unaccountable tired and sick.

Maybe math scares you.  Or worse—maybe math bores you.  Fear you can take, and anxiety in equal measure; but boredom, never.  It wasn’t time but boredom that sunk Ozymandias into the lone and level sands.  Because—

Because (you say) math is about numbers.  That’s it.  It’s just numbers.  By enumerating, you take away a spark.  That which can be counted, can be dismissed.  A mathematician is a bean counter with a pocket protector, somewhere on the spectrum, digitizing nature, walling off the soul with a wall of 1’s and 0’s.

But it isn’t true.

I could plead that mathematicians don’t usually think of numbers.  They think about patterns, symmetries, interconnectedness.  They see math in the petals of a daisy, and in the predator/prey cycle of lynx and snowshoe hares.  Math is in the strength of nanowires, and the delicacy of hoar frost, and the oomph of an engine, and the whorls of a Spirograph.

I could plead that math is about connections, structures.  Math is the study of logical systems.  Numbers are beside the point.

Beside the point.

I’m looking right now at the white-board in my office.  Ignore the calendar with a picture of Crater Lake, and ignore the poster of Han in Carbonite, and ignore the Albert Einstein action figure, and the pamphlet which says “Welcome Aboard Marine One.”  Focus on the white-board itself: it’s covered with equations, in red and green and blue, with doodles, starts and stops, arrows and spirals, letters both Roman and Greek.  There are graphs of velocity vs. time.  There’s a derivative, and an integral.  There’s Newton’s 2nd Law, half-erased.

There are no numbers on the board.

I could plead still, but here is what I know: that math is beauty, and that the whole world is math.  Here in my ivory tower, I adhere to the Mathematical Universe Hypothesis, which posits that the multiverse is itself is “just” a mathematical structure.  It’s not infinite turtles, but math, all the way down.

Jump if you like: you’ll never hit the bottom.

And what of the equation I gave?  What does it say?  To whom does it speak?

It comes from a paper I wrote, across a gulf of years and disciplines.  It says, in English, that the probability of going from quantum state A to quantum state B is the sum of all the products of closed-loop amplitudes that include A and B.

I am A.

You are B.

To get from me to you, we have to count all the ways we can interact, including ways that go backwards from you to me.

We add up all the ways.

And in the end you don’t have a number, but possibilities.

pinnacle_park_NC.jpg

I’ve talked in the past about the RGB color scheme, and about extra spectral colors.  Here I want to ask a specific question: why do some RGB color combinations have names, while others do not?

First, a review.  Most (but not all!) colors that humans can perceive can be represented (approximately) by a set of three numbers (R,G,B) where each variable runs from 0 to 255.  Roughly speaking, a 0 is “none” of that color and 255 is “maximum” of that color.  Thus (0,0,0) is black, (255,0,0) is red, etc.  What’s interesting is which combinations get names in English, and which do not.

Suppose two colors are maxed out.  (255,255,0) is equally red and green; if you’re familiar with color addition, you know this is yellow.  Similarly, (255,0,255) is magenta, and (0,255,255) is cyan.  So far, so good.

Now suppose one color is maxed, and another is at half value.  Here’s where things get interesting.  Consider (255,128,0), which is (in a sense) halfway between red (255,0,0) and yellow (255,255,0).  Not surprisingly, (255,128,0) is called orange.  But what about halfway between yellow and green, i.e. the color (128,255,0)?  Mathematically, this should be as unique a color as orange, but (sorry) it just looks like a different shade of green to me.  Why is that?  What’s special about (255,128,0), but not about (128,255,0)?

It turns out that (128,255,0) has a name: chartreuse.  But probably only one person out of twenty could identify chartreuse out of a line-up.

If you want to experiment, try the other “halfsies” using this RGB applet.  The combinations you should test are

(255,128,0) = ORANGE

(128,255,0) = CHARTREUSE

(0,255,128) = ?

(0,128,255) = ?

(128,0,255) = ?

(255,0,128) = ?

Only one of these is obvious to me, i.e. the color (0,128,255) which is halfway between cyan and blue.  That’s the color of a clear sky, and is known in English as azure.

Do any of these combinations have unique names in other languages?

Here’s a modern-day color wheel (thanks, Wikipedia!), which puts all of this into perspective:

colors

[Note that “violet” here isn’t really true violet (as in a rainbow), which cannot be represented on an RGB computer monitor.]

Are these the names you came up with?  Personally, I called (0,255,128) “dark mint green” instead of Spring Green, but what do I know.

And here we get to the psychology of color, which is the main point of this post.  Look at the trifecta of red/orange/yellow: most people would classify those as three really distinct colors.  Now look at the trifecta chartreuse green/green/spring green.  Those all just look like green, to me.  They aren’t as distinct.  And I think the reason is completely in my mind.

Think back to when you studied color in kindergarten.  The “primary” subtractive colors were red/yellow/blue.  [That’s now known to be bullshit, of course; there are no three canonical primary subtractive colors; we instead make a choice of three primaries based on what colors those three could possibly make upon mixing (this is called the gamut) and  cyan/yellow/magenta gives a better gamut than red/yellow/blue.  Put another way, if you only had three crayons, then choose cyan/yellow/magenta instead of red/yellow/blue because more mixed colors will be available to you.]  Anyway, now look at the RGB wheel and find red/yellow/blue.  They aren’t equidistant.  Something is wrong.

Here’s my thesis: I think that the red/yellow/blue bullshit we lived through at the age of 6 has biased us towards thinking that red and yellow are more different than they really are.  Look at the wheel again.  In terms of RGB numbers, red and yellow are as similar as blue and cyan.  Hard to believe, I know, but that’s the way the cookie crumbles.

One final thought: in English, in kindergarten, when you mix white with red, you get pink.  What about mixing white with green?  Or white with blue?  How come there aren’t unique names for those colors?

(255,200,200) = PINK

(200,255,200) = ?

(200,200,255) = ?