omenti

... so excited that they just start farting out light

Years ago one of the neighbor kids, probably about 11 at the time, asked me what fire is.  Sometimes frustrated parents point their question-rich kids at me.  The answer came immediately:

 

fire is what happens when atoms get so excited, that they just start farting out light

 

He cocked his head bit and he gave a  look that managed to combine skepticism with delight.  

 

 Questions are wonderful. The trick is to give a sort of accurate answer that doesn't rely on jargon or experience that the questioner might lack.  Ideally it will stir up a bit of curiosity.  Unfortunately jargon is hard to avoid and even simple terms can be a problem in any field.

 

The terminology problem is a serious issue in communicating the natural sciences. Bedrock explanations can be confusing unless you've devoted a good part of your life to them and the expert considers them easy.   Too much of the  terminology used in physics  - power, energy, quantum, theory, hypothesis, model, significant, natural, data, information, and entropy to start with - have very different meanings to non-specialists.   It is an area where I tend to struggle. 

 

Communicating science is damn hard.  I've become a  fan of better education - that a variety of approaches are appropriate and perhaps even necessary. Lectures and videos often fail because they answer questions before they arise and fail to engage deeply enough.  The printed word and pictures can ignite the thought process, but creating something that is interesting and entertaining is tough.  The best approaches seem to be multidisciplinary with different media types augmenting each other.   

 

A few days ago a strong recommendation for a Kickstarter comic book project on entropy,  I'm not a big comic book fan, but sometimes the right story, artwork and science come together at an accessible level..  

 

They're using artists with real comic book experience, a seasoned writer and a physics consultant who knows a bit about entropy.  I haven't seen the full physics approach but a friend with a Physics Nobel has and gave his seal of approval.   Before writing this I passed this by one of Sukie's friends who does comic books and illustrated children's books for a living.  He liked it a lot.  It will be about 140 pages ...

 

I'm in

 

There are only a few days left and they may not make their all-or-nothing goal, so sign on if you like the idea...   Entropy is widely understood making it a great choice.  If you permit, I'll ramble a bit.

 

A few of you love mechanical clocks.  The quintessential clock has a pendulum swinging back and forth. One of the first things you learn in high school physics is how to compute the period of a swinging pendulum.  Conveniently, at least for small oscillations on the Earth, a quarter meter long pendulum completes its cycle in about a second.   Size matters.  A grandfather's clock is slower still and a Foucault pendulum is majestically slow and it measures the turning of the Earth.    And for fun, why not express your height in terms of the period of a pendulum of the same length?¹

 

A clock of any sort measures the passage of time - a rather curious thing because it only flows in one direction from the past through the ephemeral present and into the future.  This arrow of time tells us the past is not the same as the future.   Completely obvious and hardly worth mentioning except it's connected to some of the deepest questions that exist.

 

When Newton discovered Newtonian physics, the still incredibly useful tool chest we use to describe most of the motion we encounter, there was a bit of a puzzle.  The equations work equally well going backwards in time.  So does quantum mechanics.  Physics at the smallest scale is time invariant.  But that's contrary to what you and I observe.  Outside of our dreams and science fiction we can't go back in time.

 

Entropy is the fly in the ointment.  Roughly speaking it's the measure of randomness, sort of a disorder, in a system.   Take a cup of coffee and a glass of milk.  At the level you and I observe them each is orderly.  Coffee is mostly uniform coffee and the milk is uniform milk.  Each is a low entropy system.  But mix a bit of milk into the coffee and you get wonderfully beautiful and mathematically complex swirls.    You have increased randomness in the system.  It has a higher entropy and by themselves the milk and coffee don't unmix. 

 

As time moves forward the total entropy of the universe increases.  This turns out to the why the past is separated from the future - why causes precede effects - why living things age.  The comic book should tell you more about this.

 

Curiously if you isolate a system and play around with it you can avoid the impact of entropy.  Adding energy to a closed system is one trick.  But a pendulum is very simple.  What if we made a perfect pendulum..  one in a vacuum (no air friction) and with a perfect bearing.  It's motion would be reversible.  Could you make a clock with hands that went backwards?

 

 
A clock is just a machine that turns the motion of the pendulum into a mechanical motion that moves the clock's hands  Tear one apart and you find a nifty little thing called an escapement - a wheel with asymmetrically pointy teeth.  The pendulum is rigidly connected to a two armed piece called an anchor.  It's motion allows the wheel to turn easily in one direction and effectively blocks it in the other.  If the clock was "perfect" the wheel could move the other way just as easily, lifting up and over and local time could move in either direction.

 

You have some of your coffee and let your mind wander.   There's this noise...

 

tick tick tick tick tick

 

That's the clue.  A tooth on the wheel hits the anchor and vibrates transferring a tiny bit of energy to the air making the ticking sound we perceive.  The metal also heats up a small amount.  The heating of the metal and air increase entropy.  The tick of the clock increases the entropy of the Universe a tiny amount.  

 

And there are curious puzzles.  Just after the Big Bang the early universe was very orderly... why?  Early on it must have been like a perfect pendulum or any other system that can move either way in time.  But it didn't and you owe your existence to it.

 

Max the Demon vs Entropy of Doom may be fun.  I hope it makes it's goal.  

 __________

¹ If it's swinging through a small angle you can easily show the period ~ 2Pi(L/g)^1/2, where L is length and g is local gravitational acceleration. If you're six feet tall it works out to a shade over 2.7seconds.  

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Recipe corner

 

Produce is currently spectacular.  I have a deep love for real tomatoes.  Here's a sandwich that marinates a bit.  It was spectacular with great tomatoes and would be awful with what you find in February.   This is just a rough outline so improve!

 

Gooey Tomato Sandwich

 

Ingredients

 

° a pound of ripe tomatoes..  go for heirlooms of a variety of colors. you deserve it.

° 2 garlic finely mined cloves

° 1 tsp capers

° 3 tbl extra virgin olive oil .. the good stuff here

° 2 tsp red wine vinegar

° some red pepper flakes'

° a dozen or so fresh basil leaves 

° a few fresh parsley leaves  (or substitute whatever)

° a really nice fresh baguette or similar fine white bread

° salt and pepper (a good finishing salt is appropriate)

 

Technique

 

° cut the tomatoes into thick slices or whatever shape you want.  Put them in a bowl and season with a bit of salt and pepper

° add everything else except reserve some of the basil and all of the parsley. Toss and let it rest for about ten minutes 

° split the baguette.  Spoon the mixture and it's liquid onto the bottom half of the bread.  Now sprinkle the parsley and reserved basil and replace the bread top.

° cut in to an appropriate number of pieces.. four is about appropriate here.

° cover with a clean dish towel and wait an hour before serving to let everything soak in.

 

 

 

hacking your vision

It was really stupid - not quite Darwin Award stupid - but close.  Now that my parents are gone I can write about it.

 

As a teen I became fascinated with the sensitivity of the human eye.  It turns there are a lot of tricks you can use - I've written about playing with a few subtleties of your color vision to see colors in the night sky as well as my practice of night walking on dark nights without a light.  Moonbows (like a rainbow, only from moonlight), very dim luminescent beetles, the phosphorescent decay of organic matter in still ponds and the reflection of light from the eyes of animals in starlight.  There is a certain thrill in tapping your inner owl and walking around in near darkness.   If you're a bit on the teenager side of the risk curve you can try running or cross country skiing without lights.  And then the stupid thing I tried.

 

The night was exceptionally clear with only starlight.  The hills were just black regions without stars.  Night walking had opened up part of the outdoors I didn't know, but it made me wonder.  Armed with a brand new driver's license and my Dad's old Ford Falcon,  I had driven North of town past Benton Lake on Bootlegger Trail  - far enough to be away from the light glow of town.   I pulled over to the side of the road, taped over the instrument panel so none of the light came though and let my eyes adjust to the dark.  I started the car without the lights and used averted vision to drive.  It was easy to see where the road and even the center stripe was, but everything went away if you accidentally slipped and used the center of your eye.   That's the hard part - you see a something and tend to focus on it.   Suddenly your sensitivity drops off to less than a tenth of a percent of what it was and everything vanishes.

 

I probably drove that way for three or four minutes at up to thirty miles an hour.  I did it again about a month later with a friend.  He didn't have experience with averted vision so he didn't try, but I had a witness. 

 

Don't ever try anything that stupid!  But learning how to use your averted vision is a nice way to extend your view into the natural world.  The world becomes a richer place when you learn how to see it a bit different.  It is one of my forms of travel and particularly interesting when I'm visiting dark places for the first time. 

 

You have three flavors of cones that are each sensitive to different "color" ranges.  A total of about seven million and they're mostly in an area called the fovea near the center of your retina.  There are also rods.  One hundred and fifty million - approximately a boatload. They're generally more than a thousand times as sensitive than your cones  and in some cases can be sensitive to individual photons.  Learning how to use just the cones is the trick.  

 

The fovea is small and densely packed giving you your detailed and color vision.  It's what you usually think about when you consider vision.  At it's center is a very small region about the size of a small dot of ink - about 0.3 millimeters or 300 microns.  The thinnest blonde human hair is about 40 microns in diameter and the coarsest black hair about 120 microns, so its really small!  It's all cones.  If you plot the density of rods and cones on the retina going radially out from the center (the fovea centralis) you see the density of cones drop dramatically around twenty degrees out.  The density of rods, on the other hand, is very low inside this area, and rapidly increases to a maximum around 20 to 25° out and then slowly drops off.¹  Averted vision involves looking away from the center part of your vision.  Ideally you want to be looking at least twenty five or so degrees out.  Further out the density drops, but not that fast..  I aim for about 40° to prevent accidentally falling back into central vision.  I can't do it without biting my lip - find your own technique:)

 

You can also use a camera to extend your range.  Serious photography forces you to take careful note of what's in an image and you have any number of adjustments to  play with. You can play with different wavelength ranges and see what is normally hidden to us.  I like to play with different slices of time from  tiny fractions of a second to minutes long.  

 

We have fireflies around here in the Summer. Here's a simple 30 second time exposure.  (f3.5, ASA 400 for what it's worth).  Flashing signatures vary with species and I've found four in our area. It is relatively straight forward to analyze the signals and do serious observation.   For something so beautiful it isn't deeply studied as one might think so you might discover new behavior!

 

Before stopping it seems reasonable to mention you can hack how your mind synthesizes and uses the vision it generations.  Our brains turn out to be quite "plastic".  Usage patterns can create new connections and destroy old ones.  Playing a musical instrument develops certain regions in the brain as does speaking multiple languages fluently.  Certain types of online interactions are currently under heavy study - it appears that multitasking leads to different neural optimizations along with easily finding answers without reflection.  Jheri is mostly deaf - I've never met anyone as visually aware.  She does an enormous amount of visual tracking and lip reads to the point where you don't realize she's hearing impaired.  

 

Sports are another way to hack your sense of the world.  People who are good at sports that require "field sense"- knowing the position and movement of others on the court and field- develop certain regions associated with orientation, but on a massive scale.  They're doing it for multiple moving objects.  I wonder if some people who are wonderfully athletic but aren't very good players in field and court sports have problems with this? (of course there are dozens of other areas that must work well too) 

 

All of these changes seem quite normal to their owners - after all, we can't easily know what someone else experiences.    A lot of questions arise.   A few months ago a reader mentioned she was interested in how smell interacts with the body.  It is certainly part of our interoception system and represents a nearly blue sky research area.  There must be room for hacking.   I've been talking to a neurologist and reading about dogs.  But I'm out of time.

___________

 

¹ the heights of the curves are different, but you get the idea - artistic license:-)  This is from memory, but in the ballpark.  

 

 

precision twinklers

Fifty years ago this month Jocelyn Bell was going through the chart recorder output from a new radio telescope she and a few others had built at Cambridge .  She had worked herself up to about a hundred feet of it a day looking for anything interesting in the squiggly line of ink. Very boring work.  Lots of noise and bits of the expected.  

 

But there was this "bit of scruff" when the telescope was pointed in a particular direction.  The scruff was repeating every 1.3 seconds.  Very regularly.¹ 

 

You always doubt your equipment.  Regular noise is usually something man-made or an artifact from the apparatus.  And there were those new fangled satellites beeping away,.  Carefully you try to eliminate the possibilities.  She and her advisor eliminated most possibilities, but they weren't that certain.  Then she found another bit of scruff.  That regular pulsing .. now at a different rate, but still very accurate.  Better than the clocks they had in the lab.  She had found something - something out there.  

 

There was a flurry of activity when they announced.  Astronomers around the world dropped what they were doing.  Theoretical physicists and astrophysicists conjectured.  A few of the conjectures advanced to hypotheses.  And in this swirl of activity  she found and third ... and then a forth.  And in theoryland of the hypotheses made sense.  It was called a pulsar.    

 

She had found the crack in the door to some of the deepest Nature yet encountered.

 

In 2017 something like two thousand have been found.  Shortly after the discovery it was suggested a star could collapse so dramatically that it's core was nothing but neutrons.  Imagine a mass greater than the Sun compressed down to something about a dozen kilometers in diameter.  Like a skater pulling in her arms it spins much faster than the star it started out as. The first went around every 1.3 seconds, but some spin more than a thousand times a second.  Their magnetic fields are trillions of times stronger than the Earth's and, combined with the rotation a beacon-like signal forms.  It sweeps through the sky like the light from a lighthouse as it rotates.  

 

She and her advisor opened up an entirely new and unexpected branch of astrophysics that has led to a much deeper understanding of both astronomy and physics.  Pulsars and their close relatives are hot areas of research.  And they can even be useful.  A GPS system is just a group of accurate clocks with transmitters orbiting the Earth.  Pulsars are as accurate as atomic clocks. You  could use them to build a galactic positioning system that would work anywhere in the Milky Way and not than just on Earth.   And you can make use of their regular beat to build another kind of gravity wave detector.  One that is complementary to the current interferometry technique.  

 

Some of the techniques developed since then have trickled down into important technology we use and many hundreds of astronomers and astrophysicists have spent some time in the private sector making their contributions to the economy.  Pure science is a very inexpensive mechanism for creating future value.  The "problem" is you can't predict where it might lead.

 

Hewish went on to receive a Nobel Prize in Physics for the discovery.  It is widely felt in the astronomy community that Jocelyn Bell should have shared in the discovery as her contributions were enormous.  But:    1967 and female.   She spoke of it ten years after the discovery:

 

"demarcation disputes between supervisor and student are always difficult, probably impossible to resolve. Secondly, it is the supervisor who has the final responsibility for the success or failure of the project. We hear of cases where a supervisor blames his student for a failure, but we know that it is largely the fault of the supervisor. It seems only fair to me that he should benefit from the successes, too. Thirdly, I believe it would demean Nobel Prizes if they were awarded to research students, except in very exceptional cases, and I do not believe this is one of them. Finally, I am not myself upset about it – after all, I am in good company, am I not!"

 

She's being far too generous.  This was one of those exceptional cases.  At least she's received other significant honors she's had throughout her career.

 

____ 

And something sad.  

 

I rarely use the term genius to describe anyone alive.  Maryam Mirzakhani was an exception.  A fearless mathematician, she was the only women to receive the Field Medal: math's highest recognition.  She died on Saturday at age forty.  She was just warming up.   Here's a well-written piece about her that appeared in Quanta a few years ago.

 

Excuse my political comment, but Mirzakhani was female, brilliant and from an Islamic county.   I doubt someone with these "liabilities" would be welcome here now ...

__________

¹ She recognized that pulsars are astronomical sources where others had failed because she noticed that the pulses in her data (Figure 6.1) didn’t look like other forms of interference and they reappeared exactly once per sidereal day, indicating an origin outside the Solar System.  She and Hewish, “decided initially not to computerize the output because until we were familiar with the behavior of our telescope and receivers we thought it better to inspect the data visually, and because a human can recognize signals of different character whereas it is difficult to program a computer to do so.”  Other people were using software to filter out noise and were throwing out the interesting signal in the process..   

 

 

  

lime jello marshmallow cottage cheese surprise

You'd see the differences during dinner.   Our neighbors the Eriksens had a mixed marriage.  Her ancestry was Swedish, his Danish. He liked sour cream on his jello, she went for whipped cream.  Not that jello was a Scandinavian food - they had been regionally Americanized like the rest of us.    In a generation rugbrød had become foreign, but everyone knew hot dish and jello formed around things like shredded carrots, Kraft brand miniature marshmallows, fruit cocktail or cottage cheese jiggled on our plates.  Even our notion of exotic had been Americanized. Once every few weeks we celebrated a South of the Border meal with "tacos" (pronounced tack-ohs) - toasted Wonder Bread folded in half holding sautéed hamburger, onions and some cheese.  Food from your ancestry had been relegated to holidays and properly done by the elderly.   The great melting pot included enormous dietary change.  

 

Thinking now ..  what were some of the major changes in food since the beginning of the last century?  Here's an incomplete list of the top of my head, not in any particular order

 

° enormous improvements in sanitation, sewage and clean water

° food safety (Upton Sinclair)

° cheap global transportation of fresh produce.  You can have greens every day of the year.

° a move away from home gardens for fresh produce

° a cheap and reliable cold chain... flash refrigeration near the harvest, refrigerated trucks, display cases and home refrigerators

° corn-based sweeteners

° obesity replaces malnutrition as a major health issue

° relative to average income food becomes much less expensive

° few people farm (from about half the country to about two percent)

° much less time is spent on food preparation - home cooked meals become a hobbyist activity for some

° restaurant meals become a regular experience for most people

° the introduction of ethic foods across cultures (sadly after I was growing up)

° The Haber-Bosch Process (fertilizer - this was one of the most important revolutions of the 20th century)

° Farmland being used to grow fuel for vehicles

 

Such lists are fun to think about.  Some of these changes are clearly positive, some not so much and others seem neutral.    Change is complex and frequently in the eye of the beholder.

 

A week and a half ago I spent the morning at an institute devoted to pure research - a mixture of physicists, mathematicians, social scientists and historians.  The focus of the breakfast was on change brought about by the iPhone.  No one argues it's importance as a product in terms of devices shipped and money generated.  No one argues that it defined the notion of a smartphone.  But there are a lot of interesting questions.  What does it mean culturally?  Our lives have changed, but what is the balance?  How do we meaningfully approach such questions as the history of our interaction with it is being made now.  Every generation believes they live in a period of maximum change and removing bias is tricky.

 

I won't go into details - the Chatham House Rule was in effect as usual during discussions like these - but there was a lot of comparison with television, the automobile and universal electrification.  Both of these had and continue to have enormous social impact.  The automobile physically changed architecture and cities.  Pollution has killed millions worldwide during the depression, but mobility has given us enormous freedoms to connect.   This is a very rich area to think about.

 

How do these rate if your window is two hundred and fifty years - to the early days of the United States?  The historians agreed the most impactful event in the US was the invention of the cotton gin.  We still are living with the fallout.  Oddly enough had it come about thirty years later other technologies would have been more neutral.  Of course the steam and electric components of the industrial revolution show up and you can get into interesting games like what would you rather have - electricity or your smartphone (assuming you had a communication technology that didn't require electricity)?  Of course the Haber-Bosch Process figures in as the planet's population would have been limited at something like two billion without it.   And sanitation and vaccinations extended life spans and generally increased wellness more than almost anything else. 

 

All of these have consequences and externalities.  Change is multi-dimensional and highly interdependent. Twenty years ago one of you (hi Karrie!) was in a group looking at, among other things,  change at Bell Labs.  I hung around with the group a bit simply because the questions were so interesting.  You might look at change brought by the automobile along a variety of axes ..  and I started to see it as a very large dimensioned space represented by a point that could move in time.¹ It gets tricky to think about as many of the measures are social and qualitative and many of the quantitative measures are difficult to nail down, but it's a nice mental model ..  it encourages you to think about multidimensional change that can gives different results for different people when they look at it.  If you're of African-American heritage, the cotton gin shows up more prominently for example.  

 

I've been trying to think through what happens with electrification, transportation and computation a bit more deeply these days.   Like the decade before the smartphone it's an exciting time.  Everyone knew there was going to be some sort of convergence of features driven by Moore's Law, but many of the details were hazy.  And now the impact isn't all that clear, but we know it's significant.  Today someone asked about the rumor of a laser on the iPhone 8 - a bit of thinking gives a very strong hint to something fundamentally huge.  

 

I'll quit here - one can spend a lot of time...

 

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Recipe Corner

 

I was inspired by the performances of a brilliant Canadian beach volleyball team: Sarah Pavan and Melissa Humana-Paredes.  They haven't had a lot of time together, but they're doing great things.  On Canada Day they took gold in Porec, Croatia  and a week later a bronze in another major tournament.  It seemed reasonable to toast their effort with homemade maple ice cream.   It isn't exactly safe in quantity, but for celebrations go ahead.

Extra points for using a liquid nitrogen freezing technique as smoothness is a function of ice crystal size (smaller is better) which is related to the rate of freezing (removing heat quickly is good).

Somewhat better than lime jello marshmallow surprise:-)

 

Maple Ice Cream

 

Ingredients

 

° 2 cups of heavy cream

° 2/3 cup of half and half

° 1/3 cup of whole (4% butterfat) milk

° 2 extra large pasteurized eggs  (they’re pretty easy to pasteurize and then completely safe)

° ¾ cup of white sugar

° ½ cup of Grade B dark amber maple syrup  (the original recipe calls for Grade C, but I can’t get it around here .  this gives a light maple flavor)

° * 1 teaspoon of Mapleine® imitation maple flavoring  (to get a richer maple flavor add this if you can’t get Grade C syrup)

° walnuts or pecans  (I tend to use pecans)

Technique

° Mix the eggs at medium speed in an electric mixer in a 4 or 6 quart mixing bowl. (I don’t recommend beating by hand!)

° When well mixed add the sugar and continue mixing for two minutes.  

° Add the heavy cream, half and half, and milk while continuing to mix for two minutes.

° Add the maple syrup  and mix throughly 

° Pour the ice cream mixture into an ice cream machine and churn freeze as per the manufacturer’s instructions

° When the mixture is fairly stiff add chopped walnuts and continue processing for a minute or so  (I like to place full nuts on top rather than chopped nuts inside)

 

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¹ OK - I'm a physicist..  it was screaming Hilbert Space and perhaps it makes sense to think of it like that.