omenti

a few comments on the iphone 5

A dozen years ago I took a long and stimulating walk with an obscure designer who has since ascended into international prominence.    Two weeks before a few of us had visited his company and somehow its CEO decided to invite me out for a private chat - part of this was walking with his favorite designer.

 

I'm not a designer by any stretch of the imagination, but the walk was fascinating - a discussion that bounced fluidly from material science, to Moore's Law projections, to the anthropology of Victorian women and how they dealt with sweating.   It was clear this was someone who was fascinated by connecting the dots and he somehow saw me as a like minded person.  In the end his boss made an interesting offer, but I decided to stay where I was - perhaps a mistake and perhaps not as the next two years were remarkably productive for me.

 

One of the most curious parts of that walk centered around thinking where personal electronics might be in a decade.  He was concerned with how people would relate to the devices as objects - very much part of the user interface in his mind.  He was fascinated by the stones some Victorian women would carry on hot days.  These were beautifully finished smooth pieces with just the right size, shape and density.  They could be rubbed for a soothing feeling that might calm a person if they were nervous or if the temperature was too high - they were gateways away from the craziness of the moment to a calmer state of mind.

 

It was important that the hand have access to all parts of these stones and that placed an upper limit on the size.  He noted that, given the average size of a woman's hand, it was unlikely that you could design something for handheld use with a diagonal measurement that exceeded four inches.  He speculated that devices with screens would probably have that as an upper limit on the screen size if the device was meant to be as suited as these old Victorian stones were...  We talked about such devices as a stepping stone and where you might go after that and a dozen other things.  

 

It was an incredibly stimulating walk, but the four inch diagonal measurement notion somehow stuck with me.

 

Yesterday morning I got up around three and sat in bed wondering what the lines were like at the AppleStore in Bridgewater, New Jersey.  I could drive there in about twenty minutes and my iPhone 5 pre-order had me scheduled for delivery sometime in October...  

 

since I was already up...

 

To my surprise the queue wasn't terribly long - I was about 30 in line when I arrived a bit before 4 am.  I've been to a few events like these and love the fact that a group of complete strangers is drawn to doing something that is simultaneously unusual and common.  Someone brought some excellent chocolate chip cookies and someone else had what must have been a few gallons of hot chocolate.  If you sit back and watch you can learn quite a bit.

 

On that walk in Palo Alto one of the topics of discussion was the Porsche 911.  Although far from a general consumer vehicle represents a remarkable example of constant evolution of a design that was close to ideal for the task when first introduced.   It has a distinctive character as well as what should be an impossibly awful front to rear weight distribution.  Almost everything in its design is meant to optimize its character and it can probably be considered one of the greatest automobiles of all time.

 

First introduced nearly five decades ago, the 911 has undergone a terrific amount of change, but current models are roughly the same size and shape of the originals.  It is easy for someone with one from the 1970s to get into a current model and feel the sense of connection.  The newer models are much "better", but they are also very much the same.  

 

The designer wanted to make the point that the job of the designer was to help articulate this - to work with the engineers and those who build the car, those who have to repair it and those who will use it - to find the best compromise that will work at a given time and place.  And then to participate in guiding its evolution.  He made the point that these refinements produce something that is so timely that the notion of buying the latest and greatest isn't as important as just having one and taking delight in its use.  

 

... then we talked about architecture, bicycles, violins, and watches ....

 

Apple has been updating the iPhone on roughly a yearly schedule.  Generally there is a large change followed by a smaller change.  Year to year it isn't particularly tempting to get something new.  The latest phone has improvements over the last one, but not hugely so.  But two years offers a large jump.

 

Most mobile contracts are two years.  When your contract is up the latest phone represents a big jump in capability and that makes it desirable.  At the same time you don't feel terrible a year into your contract when something new comes out.  Apple also softens the desire for the mid-contract upgrade by offering free and roughly yearly updates to the iOS operating system.  This works for about three years (four in the case of the 3GS), before a phone is too old to update.  You buy into something that generally improves in capabilities over time and the process is mostly smooth and transparent.

 

The iPhone is not perfect, but there is a uniform design language and the lesson of the Porsche 911 is relevant.  There isn't a huge amount of design difference between the original and latest iPhone - it is easy to recognize them as something from Apple.  On the other hand there has been an enormous amount of refinement.  There is a strong sense that, if you are satisfied with the product, you can comfortably stay with the line for a long time - assuming Apple remains true to the path.

 

It is popular for technical pundits to criticize new products.  Most of these people have never designed, built or programming anything serious in their lives.  They love to create specification checklists and use them as a proxy for comparing products.  This rarely gets at the user experience, design, "character", ecosystem and the anthropology of something.   There is no way I can comment on these deeply enough, but a few of you asked for an iPhone 5 review.  I'll offer a few comments now, but will put together notes for a more detailed review after I use it for a week or two.  (I won't post it here as I'm not a reviewer, but let me know if you want a copy when I finish the notes.)

 

When I finally got inside the Apple Store I was paired with Jeff Stambovsky who turned out to be good at navigating an order that was complicated by the fact that I needed to cancel a previous online order and doing so would cause a problem with my carrier's ordering system - namely it would reset the fact that I had over two years on my last phone.  He was able to contact the right people at Apple and my carrier and just make the process happen.  On top of that, while we were waiting, there was good conversation and no sales pressure.  Apple Stores do the highest sales per square foot of any store in the US.  Other brick and mortar stores should study them and a few others who have interesting approaches and perhaps learn.¹

 

Why do we think of these things and call them "phones"?  They aren't for many of us. I was talking to a European friend who notes he pays full price for a smartphone and then gets an unlimited data plan for about $13 a month ...  He never uses it as a phone, but does "voice" instead using one of several VOIP products.  He has routed around his telephone service.  Imagine being able to do that in the US.  

 

Out of the box I was startled by the weight and "feel" of it as an object.  It is very light for its size, but still has enough density to let you know it is metal and glass rather than plastic.  The fit and finish are excellent and comparable to some very high end consumer objects.  Perhaps not at the level of a really fine watch, but approaching it.  

 

The screen is excellent and the diagonal measurement, ahem, is four inches - the measurement that has stuck with me over the years.  Larger objects have their own niches, but will speak to different design languages.  Apple is about focus and simplicity.  There is a design balance and Apple speaks strongly on this - excessive choice can lead to some tragically awful design.²  

 

Good design is often about what you leave out.

 

Many have criticized the eight pin connector.  This is Apple at work and I'm amazed the old thirty pin connector survived as long as it did.  The new charging connection is much more secure, can be inserted in two orientations and allows a much slimmer case design.  Every change like this is criticized as a terrible Apple mistake and a sign the company is in a downward spiral.  In the end it is necessary to destroy some of the old and replace it if you want to prevent a Windows-like complexity from taking over.  This is an artifact of necessary housekeeping as the design evolves.  At the same time it is clear why wireless charging is not good enough to include at this point, why NFC doesn't make sense and so on.  Focus and elimination, properly done, are a good thing.

 

Transferring my mobile life from my old iPhone 4 was simple.  You have your choice of Apple's online backup system or a backup on your computer.  I chose the backup on my MacBook.  It took a couple of clicks and a few minutes to complete the task.  All of my apps, their layout, all of my accounts were duplicated - the iPhone 5 is very similar to my old phone.  This backup feature has saved me a few times.

 

There is a big noise over maps that reminds me of the antennagate kerfuffle on the iPhone 4.  I'm very curious as to why this happened and can imagine a variety of scenarios that may or may not be a power play between Apple and Google.  I don't know if there is a single driver or if both are involved - I suspect the later.  That said maps are difficult!  Fleshing them out is going to take a lot of user time as well as licensing many new sources (Google licenses dozens and dozens).  The databases will improve with time - it isn't as simple as going out and licensing or acquiring one source.  I suspect the maps will be much better in six months time and dramatically better in 18 months.

 

The maps are represented as vectors and render much faster than the old Google supplied bitmaps.  The interface strikes me as nicer and cleaner than Google's, but the flyover is only eye-candy.  Google's street mapped view is actually useful.  

 

There is something more interesting to note.  You can always bookmark the Google maps webpage in all of its chewy HTML 5 glory, as an icon and use it as a proxy for the Google Map app.  Apps, for the time being and foreseeable future, seem to work better than HTML 5 for many applications.  Apple discovered this accidentally almost immediately with the original iPhone.  Google has discovered it, Facebook stumbled and only realized it recently... ³

 

Speaking of antennagate, the antenna design seems to work well on the new iPhone, but I haven't tested it throughly.  WiFi is much improved and it can do 5 GHz 802.11n.  My old iPhone had to use the house 802.11b we provide for house guests.  

 

Performance appears to be excellent - similar to our iPad 3 and vastly improved over the iPhone 4.  I'm sure it will feel normal in a few days and going back would be impossible.

 

The screen is beautiful - colors are richer and more vivid and the off-axis viewing is much improved.  The size works well in my sort of average sized hands.  I wouldn't want something taller and certainly not wider - I find many of the current Android phones to be unusable as single hand devices.

 

Apple earbuds are not for serious music listening and the new design is not a huge improvement.  It is better for calls and the microphone must be improved as four of the five people I've talked to have noted my voice sounds different and more natural. Perhaps I was having a more natural day, but I suspect it is improved.  They stay in my ears much better than the earlier Apple-issued ear kit.  If you listen to music carefully, you'll want some better earbuds or earphones anyway.  

 

The camera continues to improve.  I don't know how many panorama photos I'll take, but it works much better than the third party apps I've used.  My trusty Sony NEX-5N is still a vastly better camera, but it is of no use if I don't have it and it is just too inconvenient to pack around.⁴

 

Passbook is a very interesting and potentially important experiment.  It addresses areas where NFC fails and may even work socially.  Really important to think about and understand.  It isn't clear if it will succeed and what success might mean for the ecosystem and others, but its success or failure is important to understand.

 

The bottom line is I would recommend the new iPhone as a great smartphone if you are currently in the market.  It is the best I've used to date.  I'm a happy camper.  I wish I was as pleased with my carrier.

 

Apple doesn't execute perfectly - far from it and they never have in the past.  But it does have a core set of principles that it uses as a guide and perhaps Jobs' best contribution has been making them part of the company.  It won't last forever, but I think it stands a chance of going on for some time.  Over time I believe we'll see this combination of design, a deep desire for simplicity, an attempt to deeply understand a specific problem and a linkage of the social and technical move in an interesting direction.  

 

There is something deep about good design and knowing something well enough to realize what gets in the way so it can confidently be left out. The principle applies everywhere and turns out to be a fundamental tool for dealing with information.  We've touched on that before and are likely to return as so many fields depend on it.

 

... much more to say, but I've used 70 of my allotted 60 minutes at this point. I'll add a recipe and post this now.  Oh - and for those who love hardware the just released iFixit teardown video.

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¹ Apple Stores have evolved over the years, but have a common core design notion and mission.  Copying them directly is probably a mistake as what works for them probably only works for Apple - the concept of brand comes into play.  They aren't perfect, but they will probably continue their own evolution.  

² A rich subject indeed.  Mass customization may offer meaningful choice and there are aspects that are very desirable, but much of the territory is unexplored.  It will be fascinating to see how design couples with it.  If you're curious about this it is an area that is of great interest to me and the reason why I spend time looking at where fashion may be going.  There is much press given to 3d manufacture, but apart from prototyping and a few niches I think it is much too early to talk about if your horizons are anything under a decade.  There are fundamental design and materials problems that need a much richer understanding than is currently available.  

³ This is a really important point and helps define a minimal ecosystem.  As much as I like some of Microsoft's current work and a few of the new phones, I doubt they'll gain enough traction to do very well.  They have a real chicken and egg problem.

⁴ My view on what creative photography is and how I should attempt it has been undergoing a huge shift in the past two years.  I'm coming to realize the kit is relatively unimportant and I need to train myself instead. I need to take a lot of photos and effectively use constraints.  It may be that my iPhone is making me a better photographer than anything else I've done.  Whatever you have, just go and shoot and shoot and shoot - and then learn how to be critical.

 

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Recipe corner

 

Today is the first day of Autumn and muffins are always good with breakfast as the weather chills and crisps.  Here is an ancient blueberry muffin recipe I use.  The secret to great muffins is to use very fresh ingredients and to barely mix the ingredients.  Over mixing just kills them...   I won't convert it to metric units.  

 

 

Blueberry Muffins

Ingredients

 

° 8 ounces AP flour

° 6 ounces cane sugar

° 2 teaspoons baking powder

° 1/2 teaspoon baking soda

° 1 teaspoon un-iodized salt

° 8 ounces sour cream

° 1/2 cup vegetable oil

° zest and juice of one large orange

° 1 pint of blueberries (probably thawed frozen ...) extra points for wild blueberries

        ° optional - topping

° 9 ounces AP flour

° 9 ounces cane sugar

° 6 ounces butter

° 2 tablespoons cinnamon

 

 

Technique

 

° Preheat oven to 375°F with a middle rack in place 

° Combine all the dry ingredients together and sift once into a large bowl, add the orange zest, and set aside.  

° Separately mix the sour cream, orange juice, oil, and eggs until completely smooth.

°  Mix the two very briefly on low speed for about one minute.  The batter should be lumpy.  

° Fold fruit into the batter gently into a greased muffin pan.

° optional

° mix topping together until coarsely mixed.  divide on top of the muffins

° Bake until springy and a toothpick inserted in the center comes out clean -  about 15 minutes.

dialing back gravity and where to stand for sport

When you jump into the air the height you reach is by how strong you are, how much you weight and gravity.  We don't have much control over gravity without a bit of serious travel, but what if we could dial it back?  Imagine travel to other worlds where the gravitational field is less - where you weigh less.  The gravitational acceleration depends on the radius of the world and its mass.¹  Relative to Earth the moon's surface gravity is about 0.17, Mercury is 0.38, Mars 0.38, and the tiny Martin moon of Phobos is only about 0.005.  

 

My vertical jump is approximately embarrassing, but Colleen is athletic and has trained hers and got to where she could raise her center of mass 31 inches.  She does this by converting energy from her muscles into a vertical velocity and reaches her peak height when that velocity has burned off - her initial energy = m_colleengh.  If you solve for h you note that if g is varied, her ultimate jump height varies as the inverse.  So her 31 inches on Earth becomes a bit over 15 feet on the Moon and 515 feet on Phobos!  Of course her weight on Phobos is only 14 ounces.

 

You can also calculate how long she would be above the ground.²  On Earth her flight is about four tenths of a second, but on the Moon it would increase to 5.7 seconds and Phobos gives a leisurely long trip of about 2 minutes and 40 seconds.

 

Imagine what sports would be like (assuming you could breathe, of course)!

 

Phobos would present some interesting challenges as the escape velocity is about 25 miles per hour.  It would be easy to throw a ball fast enough to leave the little moon and sail off into space.  You can also imagine constructing some not terribly cumbersome wings and flying around in an air filled room on our moon.  Any number of fantastic new sports could be created.    For fun let your imagination take flight and out a few numbers so you can invent some new sports for the Moon, Mars and beyond.  We appear to be wired to take delight in sport and I have no doubt this will happen some day even if it is largely impractical now.³

 

But we can move around on the Earth and find a bit of advantage for another reason...

 

The Earth spins about on its axis once every 24 hours.  There is a centripetal force from this spinning that tries to pull something off the surface. If you are on the equator the force of gravity plus the centripetal force makes you effectively a bit lighter.  At the poles the outwards force vanishes and you are a bit heavier.  A bit of physics and geometry gives the effective value for g is about 9.8061[1 - 0.00263cos(2Θ]), where Θ is your latitude in degrees.⁴  Plugging in the extremes of 0 and 90 degrees ... 

 

you weigh about 0.53% less at the equator than at the poles

 

There are a few other  terms -  one that depends on your height about sea level - you weigh about 0.11% less at 3,000 meters than at sea level....  and yet another smaller term that depends on the tides.⁵  The bottom line is that on a spherical rotating planet like the Earth with its variations in altitude there will be significant differences in the acceleration of a body due to gravity that depend on where you are.

 

If you want to lift the largest weight or jump as high as possible, you want to go as close to the poles as you can. Going to a higher altitude might hurt your athletic performance as there is less oxygen, and most Summer Olympic events seem to be held close to sea level these days. 

 

But the real world is a bit more complex.  Even if you include these corrections, very careful measurements of g show something else is lurking under the surface.  The big one is the shape of the Earth.  Our planet turns out to be far from spherical, but is rather a bumpy ellipsoid, so the altitude dependent terms needs correction.  Reference geoids are calculated and are an important component of the GPS system.  We also have high quality maps of the Moon and Mars...⁶

 

Under the surface are regions that vary in density - mountains and continents tend to be lighter material that "floats".  Maps of the distribution of mass under your feet changes depending where you are -  accurate gravitation maps have been tabulated by experimentation with satellite observations greatly increasing the accuracy of the models.  The value for g changes by about 0.2% within the boundaries of the lower 48 states.  Across the planet the difference can be as large as 0.8%.

 

Position is something you need to correct for if you care about precision weights and measures, but it is something that sport does not consider.  There are usually other factors that are larger in sports performance, so we can get away with ignoring it - but for some sports like weight lifting it may make a difference.  But if you really need to lose that extra pound and are into extreme travel ....

 

And some day we may be doing sport in spaceflight using simulated gravity (a rotating the spacecraft for example) or even on another planet or moon....  

 

... then things get fun!

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¹ The force of gravity is Gm₁m₂/r² where r is the distance between two bodies, m₁ and m₂ are their masses and G is a constant of nature.  We simply this on Earth by noting that force = mass times acceleration, so for a body on the Earth's surface the force of gravity is the mass of the object times the acceleration due to gravity.  A bit of algebra shows this is Gm_earth/r²_earth  It shows up in physics texts as g.  Your weight is the force that holds you to the planet and is just this acceleration times your mass.

The important thing to note is g depends on the radius and mass of the body you are standing on.  

² distance = gt²/2, so t = 2sqrt(2h/g) because it takes the same amount of time to go up as it does to fall.  Note that this neglects air resistance.  

³ This would be fertile ground for future completely immersive computer games where you senses can be altered - or at least a powerful enough simulation can give a sensation of very low gravitational accelerations.  

In the real universe a few astronauts managed to jump around on the moon and Alan Shepard even smuggled some golf balls and his six iron on Apollo 14 managing what was probably the more impressive shots ever

⁴ the centripetal force is mv² /R_earth where v is the speed the Earth's surface is moving at at a given latitude.  At the equator v is about 463 meters per second and it is 0 at the poles.  

⁵ At sea level g = Gm₁ /r² , so at altitude h, gh = Gm₁ /(r+h)² = Gm₁ /(r² + 2rh+h²). Noting h²/r² is extremely small and rearranging we get gh ~ g/(1+2h/r).  Note that the centripetal term changes a bit as the radius changes from r to r + h.   Plugging in the numbers this altitude dependent term where g at a given latitude decreases by about 3.92 *10^-7h, where h is the distance above sea level in meters.  It is straightforward to calculate the tidal term, but I won't in interesting of time.

⁶ Very accurate gravity maps can be made by carefully tracking the position of an orbiting satellite. The best are made using a pair of orbiting satellites flying in formation perhaps a hundred kilometers apart. They compare their relative positions to better than a millimeter.  Depending on what is directly under them, they speed up and slow down changing their separation a bit as they fly. One of the more impressive measurements in science.

 

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Recipe corner

 

Barbecued Okra

 

Okra has a bad reputation - largely from inappropriate cooking techniques. Getting it right is simple - just wash and carefully dry some fresh okra, string on a pair of bamboo skewers (don't run one through your finger!), brush with olive oil and a finishing salt like Maldon and throw on a hot grill for about 10 to 15 minutes turning a few times and brushing on more oil along the way.  

When experimenting with fresh produce it is often best to just try simple things and explore the flavors using various techniques rather than relying on many seasonings (other than salt) and other ingredients.

 

Rugbrød

 

Europeans usually have much better breads than Americans.  I'm a fan of the dark and dense ones - Danish rugbrød in particular.  Making it isn't easy and I can't find anything like it in bakeries (I keep trying - if you have a source, please let me know!).  I even wrote to the Danish embassy in Manhattan and had a reply lamenting the poor state of bread in the US.  They get deliveries from the motherland, but the staffer suggested I try a Swedish mix from Ikea.  

It turns out to work very well - look for Brödmix Flerkorn (Swedish for multi-grain bread mix). This is the old packaging.  Ikea has largely burned through that stock and has the same thing under their own brand with directions in English.  Making it is very very easy.  Just add some water to the milk carton-ish container, shake and pour into a baking pan.  You let the yeast do its thing for awhile and then bake.  It isn't the best rugbrød I've had, but it is still very good and a great basis for open face sandwiches.  Very healthy stuff too...

 

recommended!!

 

back to regular recipes soon...

catching a bit of sun

In some of the posts about sports I've noted the efficiency at converting the energy stored in food into moving our muscles is in the 20 to 25% range.  Much of the remaining energy is converted into thermal energy and we have to get rid of quite a bit of heat in the process.  In theory it is possible to convert energy from one form to another, but much of our world is less than perfect.  While energy is never created or destroyed, often its transfer or conversion results in at least some of it being difficult or impossible for us to easily use and we can talk about the efficiency of a process.¹  

 

Here are a few examples:

conversion process	type of conversion	efficiency %
large electric generator	m -> e	98 - 99
bicycle chain drive	m -> m	95 - 99
large power plant boiler	c- > t	90 - 98
natural gas furnace	c -> t	95 - 97
water turbine	m -> m	90
human lactation	c -> c	75 - 80
small electric motor	e -> m	65 - 75
best bacterial growth	c -> c	50 - 60
wind turbine	m -> m	50 - 55
steam turbine	t -> m	40 - 45
supertanker diesel engine	c -> m	50 - 55
turbofan under ideal conditions	c -> m	50
electrolysis of water	e -> c	40 - 50
large gas turbine	c -> m	40
small electric motor under 200w	e -> m	30 - 50
automotive diesel engine	c -> m	25 - 35
automotive gasoline engine	c -> m	15 - 25
photovoltaic solar cell	r -> e	5 - 30, 15 common
home refrigerator	e -> t	10 - 20
human muscles	c -> m	15 - 25
pregnancy	c -> c	10 - 15
modern chicken growth	c -> c	10 - 15
gas stove	c -> t	10 - 15
fluorescent lamp	e -> r	8 -15
beef production	c -> c	3 - 10
peak photosynthesis	r -> c	4
watt steam engine	c -> m	2.5
incandescent lamp	e -> r	0.7 - 3
beeswax candle	c -> r	1
neucomen steam engine	c -> m	0.5
global photosynthetic mean	r -> e	0.3

            Here c is chemical energy, t is thermal, r is radiant, m is mechanical, e is electricity

You'll notice that some conversion devices like large generators and bicycle chains are fantastically efficient while those that involve burning fuels, metabolism, most forms of producing visible light and photosynthesis are fairly inefficient.²

 

When dealing with systems that cascade these processes, you can often find short cuts and extract a lot of unmined efficiency.  Co-generation is an example - a large power plant with a steam engine can create a lot of thermal energy that won't run a conventional steam turbine, but can heat a massive greenhouse or office building.  Putting solar cells on the roof of a building to power electric lights may only be 10% times 10% - or just 1% efficient.  Rethinking the building and using daylight through the windows most of the time offers an enormous savings.  It can be like finding diamonds on the beach.

 

Most of our energy comes from the Sun.  The dominant source of its energy comes from a set of light element fusion reactions that are "fueled" by the crush from the Sun's internal gravity.  Most of this takes place in the densest part - well within the first quarter of its radius.  The power density is surprisingly low - about the metabolism of a lizard and about a quarter of our metabolism - but there is a boatload of star out there.  This energy is mostly radiated out into space as light - about half of it visible light.  Most of it misses the Earth - we only catch about a billionth of its output.  Some of the light is reflected out into space, some is absorbed heating our atmosphere, land and ocean and some of it is converted into chemical energy by photosynthesis.

 

We should have a hooray for photosynthesis! day.  Radiant energy is ephemeral.  It takes about 500 seconds to make the trip from the surface of the Sun to us and then needs to be captured.  It would be nasty to not be able to make it through the night or even cloud cover ...  fortunately we have this wonderful chemical fuel and our cells are filled with little chemical fuel cells.  

 

But photosynthesis is fundamental to life on Earth and its efficiency is terrible - the world average for the biosphere is about 0.3%.  This creates an upper limit on how much life can be sustained.  You can work out how much energy can be fixed by certain types of agricultural crops.  Our main food crops are highly optimized for our metabolism needs, but the overall efficiency of a field is better than the global average, but is generally less than one percent.³

 

It is fun to work out the efficiency of modern post green revolution mechanized agriculture.  The world's cultivated area has roughly doubled since 1900 (we are close to the limit now), but the energy available in the form of edible crops has increased sixfold.  This has been made possible by an increase of the energy used by agriculture on the order of 8500% - we are using about ten times as much energy per kilogram of harvested crop, but we are getting much more.  We have increased the number of people who can be sustained on earth from perhaps a billion and a half to about seven or eight billion.  

 

This is enormous progress.  In 1900 a hectare of good farmland could produce about 15 megajoules of food energy per day - about 3,600 nutritional Calories. The world supply worked out to about 2,400 Calories per capita per day - not much of a buffer if there was a bad harvest.  Now we can supply about the same for all of the world's people.4  A huge challenge for science and policy is where to go as there are no clear paths to guaranteeing a good supply of food to 9 billion people - the projected population for 2050 - given current technology and consumption trends.  A second green revolution isn't immediately apparent.

 

 We need to revisit efficiency.  About ten years ago I wrote a paper noting:

 

let light be light

let heat be heat

let food be food

The notion was that it is generally inefficient to have serial energy conversions.  It is much more efficient to eat a vegetarian diet than one that uses meat.  At this point most of the undeveloped world is largely vegetarian, but as the population becomes more wealthy, people tend towards eating more meat.  It takes about ten Calories of the energy in grain to make one Calorie of beef - and that assumes the animal is completely consumed. Poultry is somewhat more efficient than beef, but a largely vegetarian diet may be necessary to share meat with others who are newly wealthy as well as to ensure everyone has something to eat.⁵  A potentially larger problem is growing food as a fuel to displace petroleum.

 

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¹ Some people like to talk about exergy which is loosely the maximum amount of useful work in a process.  Some chemists and engineers like that way of looking at the world, I prefer using efficiency.

² It turns out there are strict theoretical limits on many of these.  One of the triumphs of 19^th century physics was sorting out how to calculate the efficiency of heat engines.  That led to a basic understanding of thermodynamics and one of the greatest mechanisms for dealing with "big data" on a scale that is unimaginable to today's big data computations.

³ Getting a handle on these numbers can be very difficult as you have to consider the question of temperature, season, water availability, pests, and energy associated with running the farm, pumping water and making fertilizer.

The theoretical efficiency for photosynthesis is about 11%, but a variety of processes make that very impractical.  Ping me if you want a detailed discussion on how many photons of a certain wavelength are necessary to fix an molecule of carbon dioxide (about ten it happens)

⁴ There is a distribution problem and a huge waste problem.  About a billion people on Earth are malnourished.

⁵ It turns out I'm a vegetarian, but I tend not to care about what others eat as that is a personal choice.  There is a huge energy advantage to that way of life and that may be important as time goes on, but currently it isn't a huge issue locally in North America.

 

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The beautiful image credit:

On August 31, 2012 a long filament of solar material that had been hovering in the sun's atmosphere, the corona, 

erupted out into space at 4:36 p.m. EDT. The coronal mass ejection, or CME, traveled at over 900 miles per second. T

he CME did not travel directly toward Earth, but did connect with Earth's magnetic environment, or magnetosphere, 

causing aurora to appear on the night of Monday, September 3. 

Picuted here is a lighten blended version of the 304 and 171 angstrom wavelengths. 

Credit: NASA/GSFC/SDO

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Recipe Corner

 

Before fresh sweet corn goes away.  It was fantastic.  My vegetable broth was incredible with all of the fresh produce this time of year.

 

Cashew Corn Chowder 

 

Ingredients

 

° 1 tbsp. coconut oil 

° 2 medium yellow onions

° 6 cloves garlic chopped

° 2 tsp. sea salt

° 2 tsp. turmeric

° 1 tsp. cumin

° cayenne to taste

° kernels from 3 ears corn

° 1 kg vegetable broth

° 1 tbsp. freshly-squeezed lime juice

° 60g raw cashews, soaked overnight 

 

Technique

 

° Heat oil in a large pot over medium heat. When hot, add turmeric, cumin and cayenne and cook for about a minute, until fragrant.

° Add onions and salt, and cook for 5 minutes until softened, then add garlic. 

°  Add corn kernels to the pot and stir to coat with spices. Cook for 5 minutes then add the remaining broth and bring to a boil

° lower to a simmer and cook until the corn is bright yellow and sweet (about 5 minutes) 

°  Remove the pot, add the cashews and blend with an immersion blender.  You can reserve a few tablespoons of the whole corn kernels for garnish if you're into presentable food.

° Season to taste.

° Return soup to the pot to keep warm. Serve with cilantro cream, a drizzle of olive oil, a few kernels of corn and plenty of cracked black pepper.

 

Cilantro Cream

 
° 60g  raw cashews, soaked overnight

° 1 tbsp. freshly-squeezed lime juice

° 1 cup cilantro (leaves only, loosely packed)

° 120g water

° 1 tbsp honey

° 1 tsp. sea salt

° pinch cayenne 

° ½ small clove garlic 

Technique 

° Throw in a blender and blend until completely smooth and season to taste

 

 

 

how big is the straw?

I'm sitting here wishing my phone would charge faster. Somehow I forgot and now I face a couple of hours of recharging time.  The frustrating thing is how much energy is being transferred to the nearly depleted battery.   My iPhone 4 has a 5.25 watt-hour capacity battery - the power rate for charging is only on the order of a couple of watts. By comparison a night light is usually a watt or two.  

 

Too bad I can't crank the power to a kilowatt or two and charge the phone very quickly - at a kilowatt you could charge the iPhone in less than twenty seconds.¹  The power outlets in your home can provide up to about 1,800 watts, so this is easy in theory, but the little battery in the phone can't absorb this much power and would catch on fire or possibly explode.

 

Many people don't have a good feeling for watts and watt hours, but energy is just energy and power is just power, so you can look at them in other units.  Most of us are comfortable with nutrition Calories - we generally have to eat about 2,000 a day to stay alive.  A candy bar is about 250 Calories, a piece of bread about 150 and so on ...  Getting down to the scale of the iPhone's battery a useful unit is the M&M at about 3.5 Calories or approximately 4 watt-hours.² 

 

Wouldn't it be sweet if Apple could make an iPhone that ran on chocolate or some other food?  Even if this food fueled battery (a fuel cell of sorts)  was as inefficient as human body, we'd only use 7 of the candies.  

 

Melts in your mouth, powers your phone...

 

But what about the power rate a snack involves?  A bag of M&M's is about 250 Calories or about 290 watt-hours.  Say it takes you a minute to dispatch a bag, the rate of energy transfer is 290 watt-hours * 60 minutes/hour or 17,400 watts - 17.4 kilowatts.  

 

Now we're transferring power!  This is about ten times the power a 120 volt 15 amp line will provide before the circuit breaker trips to protect it - also what the average electric range burner uses.  And that's just you with a small bag of M&Ms.  

 

Many of our foods are basically hydrocarbons, which are wonderfully dense energy stores. We can get away with sustaining our roughly 2.4 kWh daily energy need in a few minutes of meals a day should we choose.³  

 

That's impressive - the average home in the US uses an average of about 1 kilowatt of power.  It may burst to 5 or 6 kilowatts for brief periods, but the average is only ten times higher than the average power requirement of a person.  A family sitting down to dinner can have a power rating that would probably blow out the local line transformer if we used electricity rather than food.

 

Our vehicles have much greater power requirements that we do and gasoline stations have amazing power capacities - fueling your car turns out to be 11 million watts!4  A busy gas station may be serving ten cars at a time, so it has a power rating of over 100 million watts - a good sized nuclear power plant is only ten times larger. And it gets much more impressive at an airport. A 747-400 can take on 50,000 gallons of fuel and the ground pumps are generally rated at about 2,000 gallons per minute.  The power being transferred during a refueling is over 4 billion watts per aircraft.

 

whew - huge numbers that are only loosely tied to anything we can make sense of

 

Let's go in the other direction and think about how much power a parcel of land gets from the Sun and how much of that can be stored.  That will give us a sense of how much land is required for agriculture and is tightly bound to historic limits on population.

 

Doing that properly will push me way over my one hour limit, so it will have to wait a bit..

 

In the mean time I'm going to have a cup of chocolate gelato for a treat.  Maybe 400 Calories - say 465 watt-hours of energy.  I'll savor it over perhaps five minutes - so I'm transferring power at about 5.6 kilowatts.

 

... and my iPhone and its charger toil away at under 2 watts.

 __________

¹ Power is just the amount of energy converted or transferred per unit time so time = 5.25 watt-hours/1000 watts.  

² 1.0 watt--hours is about 0.86 Calories

³ The energy density of carbohydrates and proteins are roughly similar - about 4 Calories per gram. Fats are 9 Calories per gram, which is similar to petroleum based fuels like diesel fuel, gasoline and turbine fuel.    Also remember that the average daily energy requirement of a person is about 2,400 watt-hours (a bit over 2,000 Calories), so a person averages a 100 watt of nutritional power requirement.  Our personal power transfer rates are much higher than the electrical wiring in our homes can permit.

⁴ Filling station pumps in the US are limited by law to 10 gallons per minute, but most are throttled to half of that.  Gasoline has about 36.6 kWh of energy per gallon, so 5 gallons per minute is a bit less than 11 million watts.

 

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 Recipe Corner

 

A reader asked for another kid's recipe.  This is a very simple cake for a single person.  It uses commercial cake mixes and a microwave.  It works because there is a lot of leavening in an Angel Food cake mix, so no eggs or ingredients other than water are required.

 

Ridiculously Simple Cakelets

 

Ingredients

 

° 1 box Duncan Hines Angel Food Cake (the kind that only requires water)

° 1 box of another commercial cake mix. A richer flavor like chocolate fudge or yellow cake works well

° a bit of butter or Pam to grease a mug

° chopped nuts, dried fruit, jam, chocolate chips, etc (optional)

 

Technique

° combine the two cake mixes - I pour them in a 1 gallon plastic bag and mix well.  Seal it well!

° to make a caklet, mix 30g (about an ounce) of the mix and 30g of water in a greased microwave safe mug.  Mix in any add-ins.

° microwave at about 1,000 watts for a minute

° let it cool in the cup for about 10 minutes and pop out.

 

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And finally a plug for a something of a friend.  Christopher Lydon does some of the best interviews in the business.  Really really good.  He has been a weekly companion during my rowing sessions with his podcasts and I've learned an enormous amount from him.

His is proposing a potentially fantastic kickstarter project that deeply deserves funding.

Recommended!  I pledged...

 

 

 

 

there is a reason, turn, turn, turn ...

 A bit over 38 years ago a small band of dreamers used a bow and arrow to shoot a fishline between the then-unfinished World Trade Center towers and processed to draw larger lines back and forth until they finally managed to anchor a steel cable to both sides.   Early the next morning Philippe Petit stepped onto the cable from the South Tower at the 104^th floor level and spent the next 45 minutes stunning the city before a police helicopter threatened to pick him up and a rain began to fall.

 

Like most tightrope walkers, Petit used a large and quite heavy balancing pole.  Most people tend to think these are for lowering the walker's center of gravity to add a bit of stability, but they tend to raise the center of gravity a bit as the normal point is usually between the 51 or 54% height of a person.  The real reason turns out to be far more interesting and gets into some physics that explains a lot of Olympic sports and beyond. But before getting into that we first need a little trip in season and place, so if you can leave Mr Philppe on that thread between Earth and heaven let's go to a Wintery pond.

 

Imagine a nice frozen pond and a few skaters.   Imagine one of them knows her way around.  She is clearly used to smoothly gliding along the surface of the ice and settles into a spin with her arms stretched outwards.  She's spinning fairly quickly, but she pulls her arms in to her chest and her rate of spin increases dramatically even though the only thing she seems to be doing is moving her arms.

 

It turns out her spinning motion has a momentum - an angular momentum.  It is usually shown as L = Iω and is the rotational analog for momentum with I, the moment of inertia, acting like a mass and ω, the angular velocity acting like a velocity.¹  The important notion is this is a conserved quantity.  It takes energy to spin up a body, but once it is spinning the angular momentum doesn't change.  

 

The skater is able to alter her moment of inertia as it depends on the distribution of her mass.  It turns out it is greater when her arms are stretched out, so when she pulls them in her angular velocity must increase so her total angular momentum doesn't change.  And that is what makes Mr Petit's task a bit easier.  His long balancing pole is quite heavy and these things are often weighted towards the end.  His moment of inertia increases a lot and any tendency to rotate one way or the other is slowed - slow enough that his nervous system and muscles have time to compensate for instabilities from the vibrating wire, the wind and even slipping a bit in the rain.  It is a beautiful way to cheat just a bit.²

 

Many athletes use this - it is particularly important in sports where you are trying to rotate your body as you are flying through the air.  Subtle and not so subtle changes in the shape you wrap yourself into make dramatic changes in your spin and can even rotate you around different axes.  The reason why a diver straightens his body just before entering the water, aside from comfort, is the diver is supposed to stop his rotation - stretching like this does a dandy job.

 

You may notice a runner in a race on flat ground where acceleration is important keeps his arms fairly close to his body.  The reason has to do with angular acceleration.  Just as we have a linear form of kinetic energy there is an angular form that goes as Iω²/2 in the same way the linear form is mv²/2.   With the lower moment of inertia a runner can accelerate using less energy.  Now if you are running over unstable ground you want to extend your arms to give yourself some momentum to more easily move over these areas as well as give yourself additional stability.

 

A few posts ago I never got around to the cyclists.  I've been using mv²/2 as the kinetic energy for a bike throughout this blog but that is only an approximation.  I neglected the angular component for the wheels and the chain wheel, chain, cogs and spinning feet of the cyclist..  We can usually ignore everything but the contribution from the wheels. If we assume the wheels are the same it is Iω² , so the total kinetic energy of the bike is mv²/2 + Iω² . I, it turns out is related to the distribution of the mass in an object.  A rim that weighs the same has twice the moment of inertia as a uniform disk of the same mass and radius (in some units I_disk =  1/2 and I_rim = 1).

 

In a bike race it is important to spend most of your energy to accelerate the bike.  Lighter wheels are important as is a lower moment of inertia.  The best wheels for a bike have a light mass being careful to keep mass at the rim as low as possible.  Ideally you don't have to race with gusts of wind from the sides.  In a velodrome with no sidewind you can have solid disks for wheels as there is no wind to blow you over. This can be enormously important for some events where bursts of acceleration are required.   Outside of the calm velodrome a disk wheel is usually dangerously impractical.  The best you can do is to use exotic materials and buy or build the lightest wheel possible.³  Note that on off-road bikes it is often necessary to maintain momentum over uneven ground.  Here light wheels are not a great advantage, plus they need to be very strong.  

 

The impact of angular momentum and kinetic energy is felt throughout sport - any sport where you have to rotate or rapidly change direction.  Watch a soccer player and the position of his arms, the effort it takes in swinging a bat or someone doing any sort of throwing motion.  Notice the position of a leg below the knee as someone moves it forward when running - you make the leg as short as possible to avoid having to add energy.  It shows up almost everywhere and good technique follows physical principle.  

 

It even dictates likely partners in some team sports.  Beach volleyball is particularly interesting as there are only two players.  The amount of effort (torque) a player needs to develop to move part of her body through some arc is proportional to the square of the length of that body part.  Very tall people tend to accelerate more slowly.  Height is a great advantage for part of the beach game, but other parts demand rapid acceleration.  My friend Colleen at 6'7 had a lot of length to get moving.  Her 10% height difference over a six foot player translates into a 21% disadvantage in effort required move at the same angular velocity and even more over a smaller player.  A variety of rules seem to conspire to make the optimal height of a female volleyball player about six feet.  Colleen needed to balance her height with a very short partner - ideally someone about 5'6 and with lightning quick reflexes.⁴

_______

¹ I'm leaving out the its vector nature as well as the fact that the moment of inertia is really a tensor.  Lots of physics here that I'll just skip.  But it is important to note that ω is just the angle the body rotates through in a second it is usually expressed in degrees or radians per second. For something like a rotating wheel it is the linear velocity at an instant divided by the wheel's radius.  A small wheel turns at a fixed angular velocity covers less distance than a large wheel.

² I'm leaving out details that this applies to a particular axis of rotation as well as a calculation or two showing how much it slows him down.  

³ The best bike wheels can cost more than $7,000 a pair and weigh about a kilogram per pair.  To understand why some elite teams are willing to part with this money consider a bike where the wheels each have a mass m and the rest of the bike has a mass M.  The total energy of the bike in motion - the two wheels and the rest of the bike - is  (2m + M)v²/2 + 2(Iω²/2).   The inertia is Imr² for a wheel ..  for a thin rim I = 1, so it is must mr^2.. A bit of rearranging and remembering v= rω, we get (M + 2(2)m)v²/2  or(M + 4m)v²/2for the total energy.  Note that the radius of the wheel cancels out so you don't need smaller wheels unless they are lighter.  Also note a reduction in mass of the wheel is much more beneficial than weight in the rest of the bike - dropping a kilo from the wheels is like dropping four from the rest of the bike - and it turns out to be possible with exotic materials. Not to mention the bike is more responsive to acceleration.  No wonder they will pay so much.  And "they", in this case, is usually a professional team funded by someone other than the riders.  Some of these wheels are so close to the limit that they won't support a bike plus rider weight of over 80 kilograms - about 176 pounds.  Amateur racers use wheels that are a bit heavier and much less expensive - usually "a bargain" $2,000 or less a pair.  And the rest of us have bikes that cost less than half the price of a pair of good wheels and are perfectly happy.

⁴ Note that Kerri and Misty "balance" at a fraction under 6' and volleyball players make terrible gymnasts or divers.

 

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Recipe corner

 

Instead of the normal recipe a couple of items.  

 

The first is a discovery.  A friend is lactose intolerant and I've spent some time over the past year looking for a good enough ice cream alternative.  There are a lot of really awful products out there - and often at outrageous prices.  The best solution to date was a homemade coconut milk base that was churn frozen with liquid nitrogen to keep the ice crystals small enough to produce a good texture - I have been unable to get low enough temperatures with conventional technique.  Since that is difficult to do (I lost my easy source of liquid nitrogen and a dewar I could borrow for the asking),  I continued sampling commercial alternatives as they went on sale.  

 

Finally a winner!  It isn't cheap, but So Delicious makes a coconut "ice cream" that tastes good and has the closest texture and mouth feel to regular ice cream I've seen.  It isn't a substitute for the real thing and no one will be fooled comparing it to a super premium or quality homemade, but it is still pretty good.  I've sampled and can recommend the Cherry Amaretto, Passionate Mango and Mocha Almond Fudge flavors (I know - vanilla is the benchmark for really seeing how good it is, but I'm just looking for a substitute).  If you or a friend is lactose intolerant or a vegan, I can give this one a recommendation - even if it is spendy.  

 

I find I have to have a bit of an indulgence a few times a week to sustain my sanity during weight maintenance.  I'm in it for the long haul and you just can't deny yourself a few pleasures every now and again.  This means I can justify paying a lot for the occasional treat.

 

The other item is not food, but is an interesting paper from the Archives in Internal Medicine that may be great news if you want to have a healthy old age:

 

Midlife Fitness and the Development of Chronic Conditions in Later Life 

Benjamin L. Willis, MD, MPH; Ang Gao, MS; David Leonard, PhD; Laura F. DeFina, MD; Jarett D. Berry, MD, MS

 

Background  The association between cardiorespiratory fitness (fitness) and mortality is well described. However, the association between midlife fitness and the development of nonfatal chronic conditions in older age has not been studied.

Methods  To examine the association between midlife fitness and chronic disease outcomes in later life, participant data from the Cooper Center Longitudinal Study were linked with Medicare claims. We studied 18 670 healthy participants (21.1% women; median age, 49 years) who survived to receive Medicare coverage from January 1, 1999, to December 31, 2009. Fitness estimated by Balke treadmill time was analyzed as a continuous variable (in metabolic equivalents [METs]) and according to age- and sex-specific quintiles. Eight common chronic conditions were defined using validated algorithms, and associations between midlife fitness and the number of conditions were assessed using a modified Cox proportional hazards model that stratified the at-risk population by the number of conditions while adjusting for age, body mass index, blood pressure, cholesterol and glucose levels, alcohol use, and smoking.

Results  After 120 780 person-years of Medicare exposure with a median follow-up of 26 years, the highest quintile of fitness (quintile 5) was associated with a lower incidence of chronic conditions compared with the lowest quintile (quintile 1) in men (15.6 [95% CI, 15.0-16.2] vs 28.2 [27.4-29.0] per 100 person-years) and women (11.4 [10.5-12.3] vs 20.1 [18.7 vs 21.6] per 100 person-years). After multivariate adjustment, higher fitness (in METs) was associated with a lower risk of developing chronic conditions in men (hazard ratio, 0.95 [95% CI, 0.94-0.96] per MET) and women (0.94 [0.91-0.96] per MET). Among decedents (2406 [12.9%]), higher fitness was associated with lower risk of developing chronic conditions relative to survival (compression hazard ratio, 0.90 [95% CI, 0.88-0.92] per MET), suggesting morbidity compression.

Conclusions  In this cohort of healthy middle-aged adults, fitness was significantly associated with a lower risk of developing chronic disease outcomes during 26 years of follow-up. These findings suggest that higher midlife fitness may be associated with the compression of morbidity in older age.

Unfortunately it is behind their paywall.  The short version is regular exercise in midlife has a payoff as you age.  The awful chronic diseases are of much shorter duration and at the end of life - so your older years can be much better.  The relationship between midlife fitness and long term health has been suggested, but not carefully studied.  This study looks at 18,000 adults over 40 years and was able to focus on the final years of life.  

It isn't much of a surprise that heart disease and heart failure is reduced, but they found lower rates of diabetes, Alzheimer's disease, kidney disease, and a few others.

Modest levels seem to be sufficient - 150 minutes a week of moderate to vigorous physical activity is apparently sufficient - so swimming, jogging, cycling, etc...  My rowing would certainly qualify.  Perhaps this is why countries like Denmark and the Netherlands have lower rates of chronic disease in later life - a large percentage of the population is physically active as bicycles are regularly used for commuting and errands - a very cheap and nearly transparent way to get regular exercise.

As with many of these studies there are some caveats that came out in an interview and are probably in the paper - but it appears the underlying recommendation of getting some exercise is valid.

I find it fascinating that the Netherlands and Denmark both note correlations between cycling and lower healthcare costs.  I don't think they've performed this sort of study, but are probing the same thing.  They are able to calculate a cost/benefit ratio for building cycling infrastructure that saves medical expenses - since their governments build the infrastructure and offers universal healthcare (sigh - the civilized world), such justifications are easier to act upon.  The figure is something like a dollar spent on cycling infrastructure (bike lanes and roads, parking facilities, snow removal, and so on...) saves four dollars in healthcare costs.  This is one of the reasons why both countries are pushing for greater cycling use - overall fewer than half of their citizens regularly cycle (in the US it is about one percent of adults).

Adopting a regular exercise program can be tough as many of us are pressed for time.  I mined some of my evening "down" time - times when I would watch TV or listen to the radio.  Now I time shift with podcasts, audio books and online course lectures.  If you are selective the quality can be better than one gets sitting in front of the screen.  I generally do this first thing in the morning before starting into work.  I also had a period where I needed to lose weight and found it was essential to build my fitness level.  Now I'm in a weight maintenance mode, but the fitness component is essential.  This means I needed some coaching and motivation.  I recommend that approach - talk to someone who knows what they are doing. Some people like gyms as they get focus and equipment.  I find gyms are a pain to get to and expensive, so we have a home gym and I get coaching elsewhere.  

Experiment and find what works for you.  Perhaps it is jogging, swimming, cycling a team sport or even serious dancing ... there are many channels and all you need is to find one (perhaps even more than one) that you like and can sustain.  Here is a short piece on my weight loss and exercise program - different things may work better for you, but it may be a starting point.  I note that there are many immediate benefits from regular exercise - perhaps most impressive is the good feeling that persists for a few hours afterwards and what seems to be a somewhat greater cognitive capacity. (admittedly anecdotal)

I caught an audio stream with an author interview  - recommended listening. (about 10 minutes)

 

Midlifefitnessinterview

 

 

on a beach with the stars and the moon as company

A few days ago I was standing on a rocky Cape Cod beach at five am enjoying the starry sky.   Slowly the dawn began to approach from the East and a nearly full moon was setting in the West.  The sky was clear and stars down to about 4th magnitude were readily visible.  A darker night would have produced a larger display, but it is amazing how many stars you can see and, at the same time be able to see the moon.  

 

Sunrise was getting closer with the Eastern sky lighting up with dazzling oranges, yellow and reds.  

A rich experience like this makes you think about the wonderful dynamic range of some of our senses and the reason why our sensory responses are logarithmic.  

 

Astronomy is saddled with a bizarre and archaic brightness measurement (you find really strange historical measurements throughout science) called magnitudes. A star might have a brightness of magnitude 1 with dimmer objects receiving larger numbers. Historical conventions give a few starting points which are now abandoned as the scale is tied to other measurements.  The scale can be used for very bright objects like the Sun and moon. These bright objects have negative magnitudes as do the brightest stars and planets - Sirius, the brightest apparent star (brightness perceived by on Earth), is about  -1.5.

 

So what is the dynamic range of the human eye?  How much brighter is the brightest object you can see compared to the dimmest?

 

On a dark night with dark adapted eyes a person under 30 should easily see a 6.0 with some people in exceptionally clear areas going down to 7.0.  Using binoculars or a small telescope allows you to see much dimmer stars, but let's stick with the naked eye.

 

One of the first rigorous definition of magnitude had a difference of 100 in brightness represented by a change of 5 units of magnitude.  A first magnitude star is 100 times brighter than a sixth magnitude star.  This implies a one unit change of magnitude has a brightness change of the 5th root of 100 - a bit over 2.5 (2.512). 

A well placed full moon with a clear sky is -12.7 while the Sun blazes at -26.7 under ideal conditions.  That means the difference is about 2.512^{(-12.7 - (-26.7))} or 2.512¹⁴   If you work it out on your calculator you get the Sun being about 400,000 times brighter than the full moon.

Most of us can see a 6^th magnitude star on a really dark night, but someone with young eyes and great vision in a very dark area can go as low as 7^th magnitude.  Now the exponent is 7 - (-26.7)), so it is 2.512^33.7  This is approximately big - about 3x10¹³ or 30 thousand billion times!

 

Sweet, eh?   Your eyes are fantastic instruments!

 

You can perform a similar exercise with your hearing.  We can hear very loud (and damaging!) sounds.  Our perception of loudness is not linear, but is closer to the power of the sound raised to the one third power.  If you increase the sound level by a factor of ten you will perceive it is 10^1/3, or roughly two times, louder.  The units are decibels (dB) and the quietest sounds a human can detect are roughly 0 dB.¹  At the other end of the scale is pain, which is about 140 dB.  These are separated by 14 orders of magnitude in power!  - 10¹⁴ is an incredible range but, oddly, is close to the range of brightness the eye can handle.

 

In addition to our sensitivity to a range of brightness and acoustic levels, we are sensitive to different wavelengths of light and sound.²   Normal human vision is sensitive to electromagnetic radiation with wavelengths between about four tenths and seven tenths of a micron - about a hundredth the diameter of the thinnest blonde human hair.³

 

This three tenths of a micron range of wavelength gives us a tiny window into the electromagnetic spectrum.  Our brain interprets the shortest wavelengths we see as red - light with a somewhat longer wavelength is called infra-red and even longer wavelengths become microwave and then radio waves.  At the other end of the scale we have ultraviolet light - the stuff that causes sunburns.  As the wavelength decreases we move to X-rays and finally to gamma rays.  

 

The range of wavelength is amazing.  AM radio, by no means the longest radio waves we deal with, are as long as skyscrapers are tall.  FM radio is close to the height of a human, wifi waves are about the width of your hand and X-rays get down to atomic dimensions with Gamma-rays coming in even smaller.

 

Our eyes and ears are exquisite instruments and you may have the impression we have a good sense of our environment, but in reality we only are aware of a tiny window of what Nature has to offer.

 

But it is even worse than that.  Our eyes and ears do not deliver a perfect rendition of the information that falls on them.  It turns out a lot of filtering takes place - it has to as the amount of information around is is vastly larger than the path from our senses to our brain can handle.  We have a very effective filtering and compression - think of it as image and sound compression along with compressions of the other senses.  Much of this has a complex bias and the reality we sense is a construction of our brain.  Concepts like color, sound and music are completely manufactured and interesting quirks can be probed with carefully thought out experiments and illusions.⁴  

 

I don't mean to detract from the impressive instrumentation kit we are born with - it is mind wobbling beautiful - but we can get a much better sense of the real universe around us by building instruments and recording information with well understood biases.  Every time we come up with a new generation and type of instrument we open new richnesses in our understanding the Universe - we build this sort of apparatus to fuel and guarantee the inflation of our collective ignorance.  The telescope and microscope gave us enough of a change in perspective that we were able to fundamentally alter our views of the Universe as well as life itself.  Our window to the Universe has many more dimensions than just light and sound.  Consider the fact that our sense of time is highly constraining.  Now we can witness events that take millions of years as well as those that take place in a billionth of a billionth of a second.  We are even taking steps to understand things about our world and the Universe that are too large to appreciate - we are building computational macroscopes.  We are beginning to build synoptic instruments and techniques.

 

You can enjoy the richness of a slightly expanded window with a pair of binoculars. The clearest regions of the planet can rarely show more than 2,000 stars to someone with great vision.  A pair of 50mm binoculars extends your range down to about magnitude 10 on a wonderfully dark night.  Now you can see a few hundred thousand stars and you will be doing better than Galielo Galilei did when he rocked our notion of what the Universe is.  It is far and away the cheapest way to expand your window on the universe I know of. Try some time lapse photography with your digital camera and watch a cloud or a flower bloom.  Buy a filter and try some infrared photography.  

 

I won't dive in here, but our perceptual filtering is incredibly important.  I have spent a fair amount of time studying out of band communication - the part of human communication that is not carried by simple representations of voice and even video.  One of the things that is emerging is we, actually women, sense slight changes in shades of red very well and the amount of blood just under the skin - something that can depend strongly on health, nutrition and mood - is an important signal.  The problem is the video cameras and monitors we use are incapable of conveying this level of detail.  Audio is also poorly recorded and reconstructed and some important face to face elements are lost.  Our minds compensate of all of this, but mistakes are frequently made.

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¹ It is too easy to get very technical here as our ears respond different as a function of the frequency of the sound.  For example the quietest sounds most of us hear are around 3,000 Hz.  The response drops on either side.  At 10 kHz it is about 20 dB less - about 100 times, and at 100 Hz it is roughly 40 dB down - about 10,000 times.  Our response drops naturally and even dramatically with age and abuse.  Don't turn up that iPod!!

An interesting factoid is the the ear drum physically vibrates in response to the regular changes of air density that we interpret as sound.  At the quietest levels the membrane is moving roughly the diameter of a single molecule.  This is a rather exquisite instrument to say the least.

² I use the term "sound" loosely.  Technically our mind creates sound from the interpretation of variations of acoustic waves - regions of different pressures that travel as waves in the air at the speed of sound.  It is a definition, but it is possible to say that sound doesn't exist without an ear and a brain to interpret it as sound.  If you buy this a tree that falls unwitnessed in the woods has no sound - just acoustic waves that radiate out....

³ A micron is a millionth of a meter.  Fine blonde hairs are about 40 or 50 microns in diameter with thicker black hairs going up to about 200 microns.  The finest elements in an integrated circuit are a bit under two tenths of a micron - or about half the wavelength we call violet - the shortest wavelength light we can see.  

⁴ It is amusing that some video and audio purists prefer "unaltered" and analog signals when the senses produce and the brain processes very limited and abstract representations of reality.

 

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Recipe corner

 

First a quick non-recipe that is so good now that amazing apricots are available.  Cut perfect apricots in half (remove the pit of course:-) and dust with a bit of fresh lemon juice, lemon zest, vanilla bean sugar (I make this with old vanilla bean pods and regular white sugar).  Put on a baking sheet in a 350° or 375° oven and roast until the apricot flesh gets a bit soft.  The result can be pretty amazing.

 

And now an idea that struck.  I was looking at some cherry tomatoes and wondered how cherries would go with tomatoes.  Perhaps tart cherries with an heirloom tomato...?  So I decided to see if I could make a gazpacho based on some of the tart pie cherries I have and a tomato.  It was clear it needed cucumber, some garlic, stale bread, oil and so on - so here is the first try.

 

It is really delicious!!  I won't change it much the next time around.

 

Fruit "Gazpacho"

 

Ingredients

 

° 1 cup of pitted tart cherries

° a small piece of not terribly fresh whole wheat bread

° clove of garlic

° 1/2 garlic clove finely chopped

° a bit of olive oil or butter

° a half tomato peeled and chopped (I blanche them first to make the peeling easy)

° a small cucumber peeled and chopped

° 1/2 tsp chopped jalapeño

° 1 tbl vinegar (I used red wine)

° sea salt and ground pepper

°  50 or 60g or a couple of ounces of sour cream. (optional - it is plenty good as is, but this can add a bit)

 

Technique

 

° Remove the crust from the bread, rub the clove of garlic into the pores and fry the bread in a bit of olive oil or butter until it begins to crisp.  Alternatively you might start with garlic bread, which is what I was trying to simulate

° Combine the cherries, tomato, cucumber, jalapeño, vinegar, garlic fried bread, and garlic and blend with an immersion blender or put in a regular blender. Season to taste with salt and pepper.  Refrigerate

° To serve divide the gazpacho into bowls and add a dollop of the sour cream into each bowl.  You could top it with nice looking herb leaves or whatever.  I used a few blueberries and chopped pecans.