The Call, Column 89 – It’s 2pm: Do You Know Where the Sun Is?

28 01 2018

(January 28, 2017)

The Urban Farmer

It’s 2pm: Do You Know Where the Sun Is?

Two columns ago, we talked about the “passive solar clock”, the fact that many of the things happening on Earth’s surface are driven by the amount of sunlight received. This creates a sort of weather clock, which varies periodically over the course of one day and one year.

Last column, we moved on to the idea of the “active solar clock”, the ability of certain things on Earth – namely animals, plants, fungi, and some microorganisms – to keep track of the Sun’s position over the day and the year, and adjust their behavior accordingly. This is called the circadian rhythm. It is a feature of so many organisms, from fungi to chickens to human beings; and drive behavior like (more obviously) sleep and wake cycles, hormone levels, and reproductive capacity, but also (less obviously) mood and metabolic health.

Today, let’s expand on this last concept. I want you to fully understand how important the circadian rhythm is – including your own – and the possible side-effects of circadian dysregulation, when an organism’s brain (or whatever regulates its circadian clock) can no longer accurately discern the time of day and year.

So last time, we discussed some examples of how organisms are able to use their circadian rhythms to regulate biological things. I want to make one side note here: in general, though my language kind of indicates otherwise, it isn’t organisms making the conscious choice to use their brain’s record of solar time of day and year to do things. Rather, it is their brain (or whatever) automatically regulating lots of biological mechanisms and processes according to its record of solar time.

There are some very obvious examples of this in the natural world. Plants use a series of biochemical reactions to maintain a circadian rhythm, which they use to “know” when to flower, set seed, and go dormant for the winter. Most animals reproduce best in the spring and summer, which is why birds’ nests are filled with eggs in the spring, baby deer and turkeys emerge sometime during the warm season, and even chickens take a break in their egg-laying during the winter. Much of the life in the soil goes dormant during the winter. Almost everything – including plants – sleeps at night and is awake during the day, with the curious exception of nocturnal animals. In general, animals tend to store fat more easily in the fall, and have more difficulty shedding it in the winter. This is an adaption that helps to prevent starvation during lean months…not that that fact makes me feel any better about the numbers on the scale as of late. But all of this is driven by the circadian rhythm, and therefore by sunlight!

Looking specifically at human beings, this is regulated by the human brain. It uses a combination of neuron activity, electrical charges, and hormones to accomplish this intricate timekeeping endeavor. For example, your brain produces melatonin when it believes bedtime is approaching, and cortisol when it believes it is time to get up; these are respectively responsible for feelings of sleepiness at night and wakefulness in the morning. That’s a pretty powerful hormonal drive, huh?

So what is circadian dysregulation? I’m glad you asked! Your brain has a central clock that it tries to maintain on a roughly 24-hour cycle and another roughly 365-day cycle, based on 1) the brightness of sunlight you’re exposed to; 2) the spectrum of that sunlight (more blue light indicates morning and noon, while more red/yellow light indicates evening), and 3) possibly, the position of the sun in the sky. If you go outside, and those data points match the time of day and year that your brain thinks it is, that’s a positive feedback which reinforces your circadian clock; if they don’t match, that is negative feedback, which forces your brain to readjust. Again, how cool is that?

But there are some very widespread behaviors that can actively throw off this regulation…and nighttime exposure to blue light is probably the most significant. When you look at basically any electronic screen, or even at certain light bulbs (some fluorescents and LEDs, unfortunately), the exorbitant level of blue light in their spectrum tricks your brain into thinking that it is morning/noontime. This is the reason that, for many people, staring at their phone right before bed can jolt them awake or make them less tired, even if they were ready to fall asleep right before.

But the problem is much broader. We live in a society where it is perfectly possible – even considered normal – to not see the sun most days each week, for a few months of the year. If you work in an office, it is entirely possible that during the winter, you will go to work while the sun is rising, and leave after it sets…and spend the entire day under (bluish) fluorescent lights, staring at a (bluish) computer screen, without seeing the sun at all. The shortest day of the year was just a few weeks ago, so this problem is particularly relevant right now.

On top of this, we look at a lot of brightly-lit screens at night, we generally don’t get as much sleep as we should, and we rely on coffee to keep us awake. With all of these biologically-abnormal stimuli, it’s no wonder that circadian dysregulation is rampant in the West! But what does it look like, for a human being’s circadian rhythm to be misaligned?

Seasonal Affective Disorder (SAD) is one of the most relevant manifestations of circadian dysregulation. Some peoples’ brains seem to be more reliant than others on exposure to sunlight, in order to keep their circadian rhythm aligned. During the winter, inadequate exposure to sunlight can lead to this form of acute depression, which (at least in my experience) creates feelings of bitterness, hopelessness, and resentment. The exact hormonal mechanism isn’t quite understood yet, but the link between SAD and exposure to adequate sunlight for circadian alignment is obvious.

Another common manifestation of (probably) circadian dysregulation is metabolic disease (i.e. obesity). There is far less scientific evidence linking these two, but early studies (and lots of anecdotal evidence) have shown correlation between circadian dysregulation and metabolic dysregulation, and causation between circadian dysregulation and hormonal problems…and the relationship between metabolic health and hormonal health is indisputable. This is one connection for which I’m anxiously awaiting on more concrete science.

There are things you can do to prevent the worst effects of circadian dysregulation. Avoid looking at screens and other blue-containing light sources when it’s dark outside. If this isn’t possible, invest in a pair of blue-blocking/amber-tinted glasses, which filter out most of the blue light, and as a result prevent much of the negative effect on your circadian alignment. I have a pair that cost me $10, so if you want recommendations, just shoot me an email.

Try to get adequate sleep. I know how hard this is in modern society, and my personal demon is the shear amount of interesting things I could be doing at 10 pm and midnight and 2 am, instead of sleeping…but join me in trying to sleep at least 7 hours each night (the optimal amount varies by person), because it helps to fine-tune and properly-align the melatonin and cortisol spikes that drive sleepiness and wakefulness. Also, keep in mind that coffee helps to create an artificial increase in cortisol. This is probably fine earlier in the day, but cortisol should be very, very low at night as melatonin and sleepiness start to kick in. This means coffee in the afternoon and night = no bueno.

Finally, and this is probably the most important recommendation (alongside reducing blue light at night): get some sunlight each and every day! Last winter, which the first one of my life where I was working fulltime instead of either in school or on Christmas break, I suffered a little SAD. It took me a few weeks to realize what it was. But as soon as I did, I began taking 15 minute walks most days, during my breaks or lunch at work, and the symptoms almost immediately evaporated. When I began feeling inklings of it late this past November, I took that same action and haven’t really felt it since.

Now like I mentioned earlier, the effects of circadian dysregulation on metabolic health are much more indirect and ill-defined, so it would be harder to relate the solution of that back to taking daily walks outside. But if the disappearance of my SAD symptoms is any indication of the effect of more sunlight exposure on proper circadian alignment, I have no doubt believing that this is great for long-term metabolic health as well. (Side note: I am not a psychiatrist. I am not a doctor. This is a solution which worked for me, for a specific type of acute depression that is very well-linked to sun exposure, and more likely in someone of my genetic/geological origin. If you are suffering depression symptoms of unknown cause, I urge you to seek medical help.)

Ending on a bit more of a lighter note, there is another aspect of this that I have been giving some thought to, and wanted to share. There are some…“less scientific”, shall we say…topics that may potentially be linked to the human circadian rhythm.

The first is the possibility of a greater conscious awareness of the circadian clock, beyond its background (hormonal and other biological) effects. I tend to believe that other animals – whose circadian rhythms aren’t boggled by blue lights, sub-optimal sleep, coffee and alcohol, and spending all day in climate- and light-controlled boxes – may be more consciously aware of what solar time it is, and deliberately perform actions or adjust their behavior accordingly. Do you know how, if you find yourself in a random place and the sun is not too far above the horizon, you can sort of “intuitively tell” whether it’s sunset or sunrise? Also, do you ever have those mornings where there is something very important that you need to be up for, and your brain seems to wake you up shortly before your alarm? I feel that these may be manifestations of this phenomenon – something that other animals use all the time, like when my chickens obviously know that nighttime is approaching even before dusk.

The second is astrology. I don’t actually subscribe much to it, but there have been some cases, in my experience, that the solar horoscope accurately describes behavior. If there is any underlying scientific reason at all, that the time of year that one was born may affect their behavior, I think it is probably due to circadian effects. It is entirely within the realm of possibility that there may be subtle differences in the way a mother’s body forms and nurtures an unborn baby, depending on the time of year that this is happening, because of hormones or expected availability of resources or whatever…and that this could somehow affect the baby’s long-term behaviors. Additionally, the initial circadian alignment that a newborn baby’s brain has to perform shortly after birth, and the information about the time of day and year that its life began, could conceivably affect the formation of its brain and therefore behavior as well.

This is all speculation and “thinking out loud” so-to-speak, but those are my final thoughts.

My column appears every other Sunday in The Woonsocket Call (also in areas where The Pawtucket Times is available). The above article is the property of The Woonsocket Call and The Pawtucket Times, and is reprinted here with permission from these publications. These are excellent newspapers, covering important local news topics with voices out of our own communities, and skillfully addressing statewide and national news. Click these links to subscribe to The Woonsocket Call or to The Pawtucket Times. To subscribe to the online editions, click here for The Call and here for The Times. They can also be found on Twitter, @WoonsocketCall and @Pawtuckettimes.


The Call, Column 88 – Keep the Sun in Mind

14 01 2018

(January 14, 2017)

The Urban Farmer

Keep the Sun in Mind

Last time, we started talking about this idea of the Sun as the Earth’s “passive clock”. Each place on Earth typically gets more sunlight (read: solar energy) during the day and less at night, and more sunlight during the summer and less during the winter. This is because of the Earth’s rotation about its own axis – which forms the 24-hour, daily “clock” – and because of the Earth’s rotation around the Sun – which forms the 365-day, yearly “clock”. This predictable, periodic ebb and flow in solar energy over the course of each day and each year influences basically every aspect of the climate and Earth’s geochemical cycles, especially the hydrological cycle.

I want to make a quick aside about my terminology before we continue. I’m using the word “passive” in a similar way to how it is used in engineering. The aspects of the Earth-Sun spatial relationship that form the clock I’ve described are just that…“passive”. Nothing on the Earth is making a decision, or anything like that, to heat up the air during the summer, or increase precipitation during the winter and spring. These happen because the Earth is the passive recipient of solar energy, and its geochemical cycles are driven directly by the ebbs and flows in this energy, and all of this correlates with the periodic clock of the day and the year. The Earth responds to the changes in solar energy because it is a passive relationship – because that’s just how its atmospheric and surface chemistry works.

In stark contrast, there exists something called an “active” relationship. In engineering, a thing’s behavior is active when it is able to make decisions about how to behave, based on some sort of “knowledge” of something else. If some aspect of the Earth were somehow able to adjust its behavior in response to the daily or yearly solar clock, it would be actively-controlled. That sounds odd, right? No part of the Earth is able to actively control its behavior based on the perceived position of the Sun, right? The “active solar clock” doesn’t exist, right?

It actually does! This type of control exists in a lot of different organisms on Earth, which are able to align their internal clock to the active solar clock – the perceived, relative position of the Sun, as it changes over the course of the day and the year – and make deliberate adjustments to their behavior based on this. Plants, fungi, some bacteria, and of course, animals (including human beings) have biological mechanisms within themselves that are able to keep track of the position of the Sun over time, and use – use, not just passively respond to – that information to maintain a regular, predictable time-base, upon which to shape their characteristics and behavior accordingly. How unbelievably cool is that?!

This process is called “the Circadian Rhythm”, and getting you all to geek out about it, as much as I am right now, is what prompted these two columns in the first place. If the discussion last time focused on the cosmological, physical, and chemical aspects of the solar clock, then today’s will be the biological and…shall we say, “computational” aspects.

Bacteria, fungi, and plants maintain their circadian rhythms using complex processes, wherein hormones and other chemicals are produced and consumed in their body tissue. They need to know when nighttime is coming, or when the seasons are changing, in order to affect various aspects of their reproduction, nutrient intake and assimilation, “sleep” cycles, and all sorts of other behaviors. This is arguably more impressive than animals’ circadian rhythms, because 1) it was evolved much earlier in these more primitive organisms, and 2) is done successfully without a central nervous system…without a real brain to regulate the process, like more highly-evolved animals have at their disposal.

But for the sake of maximum wow-factor, I want to limit the rest of the column to the animal (and mostly, mammal) circadian rhythm, which is easily the most interesting. Forgive the impending excited rant, but I want to make sure you understand how awesome this really is.

Our (mammals’) brains use actively-controlled chemical reactions, well-placed sodium and potassium ions, and cellular biology to maintain an internal clock that is synchronized with our eyes’ perception of the Sun’s position in the sky! This internal clock arose via evolution like two billion years ago, and forms an incredibly intricate feedback loop between us and our environment, which can be maintained even if the information about the Sun’s position is cut off for some period of time, which all takes place in the background of our logical and emotional thought, judgment, and free will.

It was optimized over time to both drive the performance of certain behaviors – feeding, breathing, sleeping, reproduction, etc – as a function of time, and also somehow utilize these behaviors to help keep the clock in sync. Our brains are able to do this by making chemicals and eating them, and storing it all with tiny bits of electricity!

This system is so finely tuned that it could be used to calculate the actual length of a solar day and solar year (which are a little longer than 24 hours and 365 days, respectively) better than human math and inventions could, up until relatively recently in our history. If you think about it one way, the very understanding of “time” and its passage is reliant on our circadian rhythms, and this understanding underwrote the invention of a mechanical clock. Rocks and algae didn’t invent timekeeping devices, because they don’t actually know what “time” is.

We only do, and were only able to, because our brains can somehow use melatonin and cortisol, our eyes’ light receptors, nerve endings and body temperature, and metal ions and neurons to keep track of and predict where the Sun is in the sky, even when it’s cloudy or nighttime. I hope you agree with me, when I say that this might be the coolest thing about biological life that I’ve ever heard.

So here’s a basic explanation of how this works. As an embryo, your genes were used to construct your central nervous system with the implicit expectation that there was a clock that needed to be maintained, and an as-of-yet unrevealed master clock with which it needed to synchronize. Your mom’s womb probably helped with this, and created an initial synchronization even though you couldn’t yet see the Sun. But shortly after birth, your brain used the photoreceptors in your eyes to start keeping track of the Sun – its brightness, its position, and the relative amounts of different colors of light – as well as things like air temperature, to gain an intuitive, neurological understanding of the periodic motion of the Sun, and aligned that happily-awaiting internal clock that your brain was constructed with, exactly to it. And using hormones and ions and electrical signals, it has endeavored and (mostly) succeeded to maintain this clock to this very day.

You get tired at night and awake in the morning, you sleep more during the winter and less during the summer, you get hungry and thirsty and even get the urge to use the restroom at certain times, your hormone levels fluctuate…all according to this clock. Even chickens lay far fewer eggs during the winter, because their brains understand it as a sub-optimal time to be reproducing and slow that biological process down as a result.

And, in my amateur understanding, how well each of these processes are able to be performed at the expected optimal time, gives feedback to your brain that further helps to entrain your circadian clock. When your brain thinks that it is sunrise, and spikes your cortisol to wake you up, there are cues that it looks for to check whether this assumption was right…and adjusts your circadian rhythm accordingly.

It is incredibly important that your brain is able to maintain this circadian rhythm, lest it not be prepared for stressors that may challenge your wellbeing. It has been proposed that obesity and some cancers are at least partially caused, or triggered, by “circadian dysrhythmia” – the mismatch between your brain’s internal clock, and the actual time of day and year.

Circadian dysrhythmia is not a biologically-normal state, and is actually caused by the way we live in modern, Western society. Bright, blue lights at night – from phones, TVs, and other screens, as well as some light bulbs – trick our brains into thinking it’s daytime; not sleeping enough and being woken up by an alarm, drinking too much coffee and messing with our cortisol levels, spending literally all day in a climate- and light-controlled building…all of these habits create the circadian dysrhythmia with which our species has found itself plagued.

My column appears every other Sunday in The Woonsocket Call (also in areas where The Pawtucket Times is available). The above article is the property of The Woonsocket Call and The Pawtucket Times, and is reprinted here with permission from these publications. These are excellent newspapers, covering important local news topics with voices out of our own communities, and skillfully addressing statewide and national news. Click these links to subscribe to The Woonsocket Call or to The Pawtucket Times. To subscribe to the online editions, click here for The Call and here for The Times. They can also be found on Twitter, @WoonsocketCall and @Pawtuckettimes.

The Call, Column 87 – That Big Clock in the Sky

4 01 2018

(December 31, 2017)

The Urban Farmer

That Big Clock in the Sky

Imagine that you’re sitting alone in a kitchen with a leaky faucet. The water drips, drips, drip, in a steady and predictable rhythm, and it’s basically the only sound you hear.

There is a certain type of person – myself proudly included – who would slowly start tapping their fingers together with the dripping. Do you know what I mean? In this situation, I always find myself absentmindedly tapping my fingers, or hitting my knee, or clicking my tongue, aligning my own noise to that of each drip of water; or, to the clicking of the turn signal in my car, or the backup signal of a garbage truck, or any similar sound.

Right now, you’re probably wondering what I’m getting at. I know this was a weird lead in, but let me try to peak your interest. This type of activity is a good example of what we in the technical world call “clock synchronization”. A periodic ticking – whether the drumming of your fingers, or the second-hand on a walk clock, or even the digital clock signal inside basically every computer and electronic device you’ve encountered – is made to align with the rhythmic ticking of some other, “master clock”.

A human making noise in sync with a leaky faucet is probably just some psychological compulsion or whatever. But when it’s done in the technological world, it’s with an important purpose. Electronic devices synchronize their internal clocks to some master clock, whether over the internet, or a closed-circuit interconnection, or a radio signal, or something like that, because their behavior needs to be driven by some “standard” time-base. Your MP3 player needs to play Ke$ha’s, “TiK ToK”, at the correct speed, so it actually fits in the 215 seconds that are expected. Your phone needs to know the time of day, every day, so it can switch to night/day mode, monitor for notifications, and all sorts of other behavior. And your favorite clock – whether the digital alarm clock by your bedside, which uses the regular pulses that come from the electric grid to keep time, or the analog wall clock in your kitchen, which relies on finely-tuned gears and regular human adjustment – simply needs to display and maintain the actual time of day (and oftentimes the date), because the daily rotation of the Earth on its own axis, and its yearly rotation around the Sun, are the basic time-base for human society.

And with that last example, we’ve finally arrived at the main point of today’s column: the position of the Sun relative to the Earth

And it is in this last example that we’ve finally arrived at the main point of today’s column: the Sun is Earth’s “master clock”, and its position (relative to the Earth) is the steady, predictable ticking to which basically everything on the surface of our planet aligns itself.

I can’t overstate how cool that fact is. This “solar clock” was essential in the development of basically everything on the surface of our planet.

This was primarily due to energy. In the course of one 24-hour “day” – that is, one full rotation of the Earth its own axis – a location’s “daytime” in when the Earth is rotated so it has a direct line of sight to the Sun, and “nighttime” is when it does not. This correlates to solar energy delivery, with a lot of it being dumped into that area during the day, and very little at night, which is why day is generally warmer than night.

And over the course of one 365-day “year” – one full rotation of the Earth around the Sun – a location’s “summer” is when the Earth is tilted towards the Sun for the most time each day relative to other days in the year, and its “winter” is when the Earth is tilted away from the Sun for the most time each day. This also correlates to solar energy delivery, with the most energy being dumped into that area during the summer, and the least during the winter – hence why summer is generally warmer, and winter generally colder.

This regular variation in the amount of solar energy that hits Earth, over the course of one day and one year, is responsible for so much of the behavior we see in Earth’s environment. The temperature of the air, water, and soil is, of course, driven by the ebbs and flows of solar energy. The same is true of air pressure, humidity, and even the amounts of certain other gases in the atmosphere.

The entire hydrological cycle is driven by solar energy, as we’ve discussed in past columns. Evaporation is faster with higher environmental temperatures and more direct sunlight; condensation (the water turning into clouds) requires lower temperatures; the type of precipitation (snow versus rain versus hair) that forms, and the amount that falls, also has to do with atmospheric conditions like pressure and temperature.

To varying degrees, every biogeochemical cycle is driven by the delivery of solar energy, and therefore ebbs and flows over the day and the year. These, and all of the other examples above, I will call the “passive solar clock”. These are effects in our environment (and even, in some cases, in biological organisms) that happen because of the amount of solar energy reaching Earth, and change based on the periodic changes in that energy.

I call this the “passive” clock to distinguish it from (what I think is) the much more interesting “active solar clock”: information about where the Earth is in its daily and yearly rotation, based on the Sun’s position in the sky and other indicators. Many biological organisms are able to use knowledge of this active solar clock to maintain their own time-base, synchronized with the Sun, and shape their characteristics and behavior accordingly.

If what we’ve discussed today can be described as the cosmological, physical, and chemical aspects of the Sun as Earth’s master clock, then next week’s column will be the biological and…let’s say…“computational” aspects. That is largely more interesting in my opinion, and can shed a lot of light (see what I did there?) on the way things behave in our environment. I can’t wait!

My column appears every other Sunday in The Woonsocket Call (also in areas where The Pawtucket Times is available). The above article is the property of The Woonsocket Call and The Pawtucket Times, and is reprinted here with permission from these publications. These are excellent newspapers, covering important local news topics with voices out of our own communities, and skillfully addressing statewide and national news. Click these links to subscribe to The Woonsocket Call or to The Pawtucket Times. To subscribe to the online editions, click here for The Call and here for The Times. They can also be found on Twitter, @WoonsocketCall and @Pawtuckettimes.