Monday, 9 May 2022

Some Green Energy Reality

 There is a big push everywhere to reduce our use of fossil fuels, replacing them with renewable energy sources, such as solar or wind power.  This pressure, of course, is driven by climate change ideology and related concerns about a warming planet.  The most eager folk hope that we will be "carbon neutral" by 2030, urged on by the United Nations and recent IPCC edicts and warnings.  Regardless of how important you think the issue, the push for "clean energy" will doubtless continue unabated for a long time.  Under the guise of "net zero", to stop emitting carbon dioxide from burning coal, oil and gas, many governments and industries are slowly installing more wind and solar power.  Those both produce electric power, so there is also a push to switch vehicles and various industrial processes over to electricity. 

The often unrecognized problem with wind and solar energy is that they are intermittent; the sun doesn't shine at night, the wind often does not blow, and clouds come by at random intervals.  To make up for the times when renewable energy is unavailable, requires some form of backup energy storage medium; a system that can easily convert from electric grid power and back again in a controlled and practical fashion.  Replacing all other electric power sources with wind and solar would require absurd levels of backup storage for many days, or even weeks -- to get us through a Canadian winter, for example. 

To explain this better, consider a modest city of one million people, which typically requires 2 gigawatt (GW) of electric power on average, with likely variations between 1 and 3 GW. If all of that must come from wind and solar, the city would need at least 6 GW of solar and wind generating capacity to get an average around 2 GW, and a minimum of 30 GWh (gigawatt-hours) of backup storage just to make it through one windless night.  That is equivalent to more than 500,000 electric car battery packs.  Even then there would be a high probability of frequent outages.  Maintaining a truly reliable grid solely with wind and solar power would increase these numbers further.

Of course by 2030 wind and solar will NOT provide all our electricity no matter how loud the alarmists shout and the green people dream.  Nuclear energy will still be around, providing constant base generation (24/7), and with new technology, nuclear may be pressed into moderate, long-term growth, if governments can deflect or appease the anti-nuclear crowd.  However, nuclear power cannot easily be dispatched; that is turned up and down at a moment's notice to match the instantaneous demand in the power grid.  Nuclear takes days to start up or shut down properly and works best operating at a constant output power - hence the base supply.

Then there is hydroelectric power, which is somewhat or partially dispatchable, providing some limited "energy storage" by way of water reservoirs - not nearly enough, of course, to replace reliable and fully dispatchable fossil fuel plants, but some.  And hydro-power cannot be expanded much since all the good sites are already in use.  In addition to solar and wind, there may be other renewable energy sources that can run on stored energy; e.g. fuel cells and hydrogen, although I personally would not invest in that (see more below). 

Dispatchable loads may also come into play: allowing your air conditioning or electric vehicle recharging to happen at the whim of the grid controllers, so as to shift their loads into times when power is abundant - all for a modest reduction in your cost per kWh.  Mind you, industry and commercial enterprises have so far not been keen to accept brownouts in return for reduced rates, but some degree of "load shifting" should be palatable to most people if done well.  In addition, there will continue to be modest improvements in process efficiencies: better insulated homes, tightened up industries, reducing energy and heat waste a bit. Together these may reduce or flatten peak loads through the day.

These changes, together with the inevitable residual natural-gas generating stations (which are very dispatchable), other traditional generating plants, and possibly newer power sources such as biogas, ethanol and biodiesel, would greatly reduce the amount of energy storage required as we move toward a more sustainable future.  Nevertheless, huge investments in energy storage for electric power will have to be made if we want to continue adding wind and solar capacity while keeping our power grids reliable, as every consumer expects. 

The obvious choice for electric energy storage is batteries.  When grid power is plentiful, AC power is rectified to DC and used to charge electro-chemical battery cells.  When extra power is needed, the batteries discharge through inverter circuits to feed AC power back into the grid.  The current front-runner in this regard is rechargeable lithium batteries of varying internal chemistries and constructions.  Encouraged by the growing EV market, lithium cells are slowly getting better and less expensive.  They have a high round-trip efficiency (kWh returned to the grid vs. kWh required to recharge them) around 80%, are rapidly dispatchable in either mode, and have a decent usable life.  Potential problems with limited materials resources can probably be worked around over time, and the cells can be recycled. 

Large (gigawatt-hour - GWh) battery storage plants are currently in planning or under construction. They are intended to shift loads by a few hours at most, not by days or weeks, and even so, they will be expensive.  Many such plants would be needed (terawatt storage!) to do away with fossil fuel generation altogether, so that is unlikely to occur by 2030. 

There are other, often-hyped energy storage media possibilities, such as pumped water, compressed air, hydrogen, thermal storage, flywheels, artificial fuels, raised heavy weights, and so on.  However, they all suffer from either low round-trip efficiency (e.g. hydrogen, air, thermal), capacity and scalability issues (pumped water, raised weights), or large capital costs (most of these).  These technologies will find small, niche markets, but are unlikely to provide grid-wide backup power at the required level.

Combined with their low operating factor (less than 40% of the time storing and less than 40% releasing stored energy) means that any stored power supply is expensive on a dollars per delivered kWh basis (both capital and operating) compared to raw solar/wind or most traditional energy sources.  As far as I am aware, no other energy storage technology can match batteries for high efficiency, flexibility, and response time.  Yet even batteries can provide backup power at less than 33% utility (80% efficiency, combined with < 40% discharge time).  Thus, if a battery plant and nuclear plant cost the same on a per kilowatt rating basis (I doubt if they do, but just suppose), then the long-term cost per delivered kWh of the battery plant would be at least three times that of the nuclear power plant, depending on other assumptions and variables.

Ultimately, of course, reality will have its way.  Yes, we will get additional solar and wind energy, some large (but limited) battery storage plants, some percentage dispatchable loads, more nuclear, and slivers of additional hydro and other sources, but we will also keep many clean gas-fired turbine generators; and probably more than a few other carbon-based power plants will continue operating after 2030. Perhaps by then the "climate change" demands will become sufficiently subject to reason that the push for "net zero" will fade, diminish, or quite reasonably be pushed out a few decades more.

In the end, reality always wins, and we will continue to have a mix of energy sources and storage media going into the future.

Sunday, 12 September 2021

The Bad Design Argument

 In the study of the history of life on the Earth, there are two and only two reasonable explanations. Either a mind - AKA intelligent agent - played some role in directing evolution over the past 4 billion or so years, as claimed by Intelligent Design theory (ID), or else there was no intelligence involved and life evolved by random chance, natural selection, and other unguided, natural processes, as held by modern Darwinists. Any proposed alternative must be one or other of these, and of course, any mix of these two is still ID at some level. 

At some point in debates about Intelligent Design, you will likely hear comments about how badly the human body (eye, hand, reproduction, etc.) or some other animal is designed. A brief statement will usually follow to the effect that, "God would have made a better design if he was the designer, therefore there is no designer and evolution is true." This presumptive "logic" can come in different guises, usually with along with some supposed examples of "bad design". However, for a variety of reasons, which I will explore, this is a bad argument.

The "bad design" argument is usually brought up by atheists or materialists who do not believe in God. Yet here they pretend to know what God should have done, based on their own ignorance of the design and of any relevant theology. The hubris and irony here are thick! They assume a series of "bad designs" and suggest that those must have come about by an unguided, and hence imperfect, process; i.e. Darwinian evolution. Note however, that even if their examples of poor designs in life were true, even poor designs require a designer! An incompetent designer is still a designer and the "no designer" conclusion does not automatically follow from the "poor design" judgement. ID theory does not require that the designer be the God of the Bible, even if he is the obvious candidate.

Nevertheless, such summary judgements about "bad design" are usually also wrong in the sense that a detailed study often shows that the particular feature in question is in fact a good design for reasons not appreciated by the accuser. One example is the supposedly "reverse wired" human eyeball, where the optic nerves are in front of the retina, thereby blocking some of the light. The human appendix is another example offered as an unnecessary evolutionary left over serving no purpose. These and many other "bad design" claims have been refuted. See this article for some examples.

This raises another point; the person making the "{bad design" call is usually just passing along some meme that he has read or heard and has no real understanding of the biology or physiology in question, much less the alternative explanations. Thus it is often merely an argument from ignorance. A wiser approach would be to learn more about the feature or design in question before passing judgement on it.

In general and especially in engineering design practice, it is impossible to judge someone's design without knowing the design specifications and constraints behind it: the purpose, capabilities, cost, schedule, regulations, available materials, limitations, and so on imposed on the design process and resulting product. As an erstwhile systems design engineer, I can state unequivocally that there is no such thing as a "perfect design". All designs are an attempt to optimize some aspect of the designed item within the constraints of the project. All designs can be "improved" by additional effort and cost, but once a design is deemed "good enough" it is usually released to meet the schedule. 

All designs also involve trade-offs among various parameters and constraints. Without knowing all of those, it is unwise to judge the resulting product or process. Of course, we all complain about products that don't work properly, or that break because they were cheaply made. But those are human-designed products, none of which come close to the complexity and integrity of even the simplest living creature. Humility is therefore a better starting place in judging the fitness and merit of any human design, and even more so for designs found in nature. Indeed, more and more these days engineers are looking at design in nature for ideas on how to improve their own products.

Another point is that no designed thing operates in a vacuum, apart from the rest of the world. Everything is part of some larger system which it must interact with and perform within. Every living thing is part of a broader ecosystem where it plays different roles, and those interactions raise additional constraints that need to be taken into account from the design perspective. For instance, in principle, herbivores could be made faster or more powerful than the carnivores preying on them, but then the carnivores would die out, unbalancing the ecosystem. From the herbivore perspective, they might feel they are poorly designed, but a higher level viewpoint shows that ecological balance is more important.

Since the "bad design" argument is usually an attack on Theism, some additional things may be said about their ultimate target: God and (usually) Christianity. Note that God never claimed that creation was "perfect", he only judged it as "very good". Perfection apart from God is not possible. Moreover, once creation was completed, things started to go down hill quickly, initially due to the Fall and the entrance of sin into the world, which messes with everything (see Genesis 3). 

Moreover, due to entropy, all of the created world, including humans, began to break down and collect imperfections. As with any designed item, wear and tear, environmental effects, usage past its best-before date, abuse, and other realities cause even well-designed things to stop working, break down, or work poorly. Some seeming design problems in humans can be traced to errors finding their way into our genome. For example, humans cannot make Vitamin-C due to a genetic defect, and of course, many diseases can be traced to errors that have crept into our genome over time.

The next time you entertain (or are tempted to make) this "bad design", anti-ID argument, think first and ask yourself, "What have I designed so that I can judge a complex system like the human body?", or "Have I examined the design constraints and purposes for this particular item being judged?" That should slow down the negativity and allow the debate or discussion to proceed in a more useful and meaningful direction. By all means, keep up the discussion, but please base it on defensible evidence and reasonable arguments.

Wednesday, 16 June 2021

Two-Dimensional Time?

The space-time continuum we inhabit has three spatial dimensions and one time dimension - as far as we know.  For us, it is easy enough to visualize fewer spatial dimensions.  A one dimensional world is merely a straight line.  A two-dimensional world is a plane; e.g. x and y axes on a graph.  In 1884 Edwin Abbott published a fun book called Flatland: A Romance of Many Dimensions, exploring how life might be for two-dimensional creatures, and how mystified they are by a 3D visitor to their plane.  Some mathematicians claim to be able to visualize a four-dimensional space with tesseracts, hyperspheres, etc., but that is difficult for us, stuck as we are in 3D space.  Some cosmological theories of reality; e.g. String Theory, call for 6 or 10 or even more dimensions in all, but some of those are supposedly curled up so small that we cannot detect or experience them.

In all of these cases, however, there is but one temporal dimension.  Aside from relativistic time dilation effects, we all share the same passage of time, and the time where you are is the same - apart from time zones - as for me.  We all pass through time - which no one fully understands - at the rate of 60 minutes per hour, and your hour is the same length as mine, even if they feel different subjectively.

One temporal dimension is well understood, even if we do not quite know what time itself is (a deep philosophical conundrum).  An existence having no time - a zero time dimensional reality is easy to think about as a fixed space where nothing ever happens: no movement, change, or even thought, as in a still photograph - not a very interesting existence.  Looking for more complexity, we can ask, could there be more than one time dimension, even in principle?  I have spent some time trying to wrap my mind around what that might mean and how it would work, and finally chanced on a simple way to express and visualize an existence with two temporal dimensions - 2D time.

Consider a teen playing a video game.  The teen has his own passage of time, and the game has another, virtual timeline as events in the game occur.  These two times need not be the same, indeed, they often are not, yet they exist together.  In the game, hours may pass in a few minutes of the teen's time, or the game time may slow down, taking several player minutes to get through a few seconds of intense action in slow-motion.  What's more, the player may save his game and then shut it down, effectively freezing time inside the game, while his own clock continues to tick.  With the "save game" feature, he can even go back to an earlier game time if his avatar "dies" in the game.

Such a game is an example of a computer simulation.  An engineer develops a program in some software to simulate some physical process, in order to better understand what is going on, or to test and optimize his design.  The time dimension in the simulation does not begin until the engineer starts the simulation running at t = 0.  Note that in the simulated reality, there is no "before" this time.  Simulated time does not exist before the simulation begins - or alternatively, it is stuck at t = 0 until the engineer presses the "go" button.  Meanwhile, of course, the engineer's own timeline continues undisturbed; he works, goes home, eats, has coffee breaks, sleeps, etc.

This two dimensional time reality can be visualized in the following graph.  It has two independent time dimensions, te for the engineer's time in the real world, and ts for the timeline in the simulated world.  In this example, there are no spatial dimensions shown; size, shape, motion, etc. do not matter for this explanation.  Of course, a spatial dimension could be added, but that is harder to do on a 2D screen, and unnecessary for the description.  We can walk through events in this 2D temporal plane as follows:

1. At te = 0, the engineer has not yet started the simulation, so ts is stuck at zero, while his te proceeds at the usual rate.

2. the engineer presses "go" and the simulation begins.  If the rate of time passage is the same the line would then rise at 45 degrees, but in this case, the simulation time runs faster than the real time te.

3. the engineer decides the simulation was running too fast, perhaps missing some details. So he slows down ts to run slower than his own time.

4. the engineer doesn't like what he sees, so he shuts it down, resetting ts to zero.

5. after a break, during which he tweaks some initial conditions or parameters of the simulation, he starts over, this time with a different ts speed.

6. stopping the simulation, he spends some time looking at the results.

7. liking what he sees, he sets ts back to an intermediate value, so that he can watch it again, 

8. finally, the engineer lets the simulation carry on for a longer simulated duration.

With this example, it is easy to see how different realities could experience different time dimensions in the "same" world.  In such a situation, the simulation "experiences" one time dimension, as programmed by the engineer.  The engineer however, experiences, or at least understands, two time dimensions; his own and that inside his simulation.  Note that the engineer's time, te always increases at the same rate.  He cannot stop or go back in time, only move forward at the normal rate.  Note too that other engineers may be running other simulations, each with its own timeline, but presumably those simulations do not interact with each other on different timelines, and so, while there may hypothetically be other parallel time dimensions, they are just different versions of the 2D time discussed here and do not truly add more dimensions.

Another way of considering 2D time is while reading a printed fiction story.  Time begins in the story when you begin reading the book, and it passes as you turn the pages, until you put the book down, which freezes the story's timeline.  The story time may pass quickly or slowly as you read, depending on the context of events in the book.  Indeed, many books jump back and forward in story time as one reads, but you understand the book has a single unified timeline.  In principle, after reading the book through, you - like the author - can consider all of the story timeline at once, at least in memory.

Having understood this approach to two-dimensional time, we could postulate a third time dimension; perhaps God's own timeline above us, in which his eternal time dimension encompasses but transcends ours.  Whether time truly "passes" for God, we do not know, because we cannot envisage, much less experience God's time.  However, he may see all of our timeline at once as we do for the engineer described above, by looking at the above graph.  Over all, in addition to his own divine time dimension, td, God may experience or at least observe and control our created time line, te, along with that in the engineer's simulation, ts, if he is interested in that detail.  Hence, in some sense, for God there can be three-dimensional time!

In principle, the engineer could "play God" by programming a simulation that includes a built-in simpler simulation with its own separate timeline, tss, but that gets rather convoluted, so I won't go there.  Suffice it to say that the concept of a simulated reality makes thinking about two or even three dimensional time more understandable.  Now if your timeline and mine were different, yet we could somehow interact when they came together, that would be closer to actually experiencing two independent time dimensions at once.  That is harder to wrap our minds around, although some sci-fi tales and superhero movies try to do that; e.g. stopping or slowing time for the world while the superhero action continues.

For some further exploration of the weird possibilities that God's control of our timeline might allow, see my previous posting at:  For example, as in the engineer's simulation, God could perhaps stop or even reset our timeline for his own purposes, and we would never know!

Thursday, 18 March 2021

Renewable Energy Sanity


I like wind power and solar power, I really do. I taught a course on alternative energy once and I worked for years in photovoltaics. I am all for using these technologies where they make sense. Home use, remote sites, and small additions to utility grids are great. But they run into serious problems when trying to fill more than perhaps 20% of the demand load on a power grid.

Any AC power grid has to balance supply (electrical generation in watts) against demand (the total load on the grid in watts) continuously, second by second in order to maintain the voltage and frequency of the grid. A grid consisting of soures and loads has almost no energy storage capacity. If the load exceeds the supply even for a fraction of a second, the voltage will dip, reducing the power to all loads, thereby dropping the total load down to match the instantaneous supply. If the generators push out too much current for the total load at any moment, the voltage will increase and the load will rise to compensate.

A grid with variable sources and varying loads is kept stable by having some control mechanisms, and by adding some storage elements to ride through instantaneous variations less than a second or so. Overall grid loads are somewhat predictable: typically peaking during the afternoon and reaching their minimum in the middle of the night. Weekends and weekdays provide other changes, as do high and low ambient temperature extremes. But any grid needs quick control mechanisms to handle sudden load changes, line faults, or sudden generator shutdowns.

Power generators have different control time frames. A nuclear power plant can be slowly adjusted on an hourly basis, but takes a day or so to properly shut down, and longer to start up. Thus nuclear plants usually provide a steady base load, perhaps up to 40% of the maximum load for the grid. Always on, and almost always the same power supplied into the grid.

Hydroelectric and coal/oil fired plants can be adjusted more quickly, but still take minutes to ramp up or down smoothly. Gas turbine generators are quicker, and are may be used to make minute-by-minute changes to the supply side, in response to other grid changes. Those supplies can therefore make up the variable parts, or peak loads, during the day, often being scheduled (dispatched) ahead of time for the expected changes.

Most grids now have some capacitors or batteries for sub-second control of small, fast changes. These are electronically switched in or out as needed. In some cases, certain loads can be placed under grid control to shut them down if the net supply cannot meet the instantaneous load demand. In this way, a large grid keeps the voltage and frequency within tight constraints as required by the government regulators.

Now add alternative energy into the mix. Solar power drops precipitously when clouds cover the sun, and of course falls to zero at night. Winds are notoriously variable, so wind power output is constantly changing in unpredictable ways. This is not a problem if the sources are a small part of the grid; the existing storage and control mechanisms can make up for the variability using other sources or shutting down loads as needed. However, as governments and people seek to use more "green energy", the percentage of the grid supplied by these alternatives goes up and starts causing major problems for the utility.

Some examples: California, in the summer of 2020 when rolling blackout had to be used because there wasn't enough power from the renewable supplies to meet the demand. Ontario has a similar problem: its contracts with wind and solar require it to pay top dollar for "green energy", whether it is needed or not. As a result, Ontario must often give away megawatts of power to other jurisdictions when the supply exceeds the demand, even as they pay for solar and wind energy, losing money overall in the exchange.

To maintain a stable grid in Ontario, the utiliy keeps gas turbine generators spinning with zero output, to kick in quickly when the wind or solar drops out suddenly. Clearly this is inefficient, and the resulting emissions detract from the supposed pollution-free wind and solar generation.

To grow the percentage of the grid beyond say, 20% wind/solar requires adding massive energy storage capacity. This isn't just a few batteries here and there. If the grid was 60% renewable, for example, it would need many hours of backup storage for those cloudy days, or weeks with little wind, to meet the peak load demand. Worse, when winter comes, there isn't much sunlight: in Ontario, for example, November averages two hours of direct sun per day, compared with perhaps 6 plus hours in June. Trying to balance supply and load over the seasons would require ridiculous amounts of energy storage.

This raises another issue. If you want a 100% renewable energy grid, you need to size the peak supply to more than 200% of the peak load. That is needed to average out the day-night cysles on the solar and the calm/windy weather for wind turbines. That becomes rather expensive, of course. Even if a watt of rated solar power is cheaper than a watt of rated nuclear power, the nuclear can run 80% of the time or more, year round, while the solar can barely operate 30% of the time at that level, at best, and much less in the winter.

For a 100% renewable energy grid in Ontario, the grid would have to provide Terawatt Hours (TWH) of backup energy storage to ride through the ups and downs of the solar and wind generators, while meeting the load demand and matching the load variations. Doing that with batteries would be insanely expensive, even if Ontario could find that much capacity to purchase. 

There are other energy storage technologies. Flywheels, compressed gas and hydrogen storage have all been touted, but they too are pricey or the round-trip efficiency is poor. The best current method is pumped water storage: pump large volumes of water up a high hill to a big reservoir when power is plentiful, then let it run downhill through a hydroelectric turbine when peak power is needed. This can be fairly efficient, and can store lots of energy if you invest in huge pumps, reservoirs and infrastructure. But even so, there are not that many suitable locations.

Fortunately, for places like Ontario, the situation is not quite so dire. Nuclear power plants provide the base supply around 50%. Hydro power provides about 40% of Ontario's supply, and hydro-power sites are often good candidates for pumped storage: you already have the volume, the turbines, and gravitational head, at least in some places. Mind you, you cannot back up or turn off a river very far or for long. 

Most utilities in North America are not so fortunate as Ontario, depending as they do on fossil fuel (coal, oil, gas) for most of their electricity generation. Using nuclear and hydro as your principal sources, and adding solar and wind, with significant storage of some sort, is probably the most practical way to go to get up over 60% non-fossil-fuel supply mix in most locations. Even so, pushing wind and solar beyond perhaps 20% of the total will require massive additional storage of some kind. 

Perhaps at some future time a more steady renewable energy source will be developed, or maybe the cost of large-scale energy storage will drop significantly. Something like that would be essential to get to a fully renewable, reliable utility grid without nuclear and hydro power. Until then, we can make marginal improvements, supply mix adjustments, and storage additions as feasible and financially practical. But until then most utilities will depend on various forms of fossil fuel power generation to keep our electric grids running reliably.

Tuesday, 19 January 2021

Mental Reality Theory

In philosophy, there is a long-standing debate -very long standing, over thousands of years! - about the fundamental nature of reality. On one side, realists claim that the world we think we see and experience around us is indeed real, made of matter and energy, and that the things we see around us exist apart from our awareness of them. Idealists on the other hand believe that the only reality we know for sure is what is in our minds. Everything else is simply sensations we experience with our minds. There may be no external reality, or it may be quite different from what we think we experience.

While idealism seems very odd to most at first glance, it is actually a well-founded position, giving rise to the "brain in a vat" idea, or more recently, The Matrix movie series, where what we experience inside our heads does not correspond with what is really happening. Indeed, everything we think we experience is merely nerve impulses coming into our brains. Who knows whether those impulses relate to anything real? Maybe some mad scientist is sending us prepared nerve signals as part of his experiment. Moreover, even the concept of nerves and a brain are based on a supposed external physical reality (EPR) that we have no direct access to. We could, in principle, be a simulation in a computer, or worse, a scripted fictional character just passing through the plot as someone else turns the pages. As weird as it may seem, there is no way to be absolutely certain that one of these situations is not true.

In one current manifestation, idealism is sometimes called Mental Reality Theory (MRT), the claim that all of reality is mere mental activity in some non-physical reality. There is no EPR, no external world. The entire world consists only of mental activity, perhaps shared with other minds at times, but nonetheless, devoid of any actual physical matter or energy. Everything we claim to experience is just sensation of mental activity in our minds.

The proponents of MRT claim that they can prove their case, and they point to a variety of evidence in support. As well as the above fact that all experience is based on sensations perceived only by the mind, they have related arguments. For instance Descartes' "cogito ergo sum" (I think, therefore I am) is the only thing anyone can know for absolutely certain. Any other "fact" is based on assumptions, tenets, or presuppositions that cannot be proven.

Recently, MRT advocates also point to quantum physics to "prove" that matter does not truly exist - it is all just interacting wave functions. And they apply the Copenhagen interpretation of quantum physics to say that mental activity - the observer effect - determines even physical reality.  By discounting matter and energy and expanding the role of thought, they claim support for their views.

But no so fast! While the alternative of believing in an external physical reality cannot be "proven" mathematically, I believe there is considerable evidence available to each of us to cast MRT into doubt and perhaps balance the debate again. I will present several such arguments: consistency, interactions with others, shared reality, children, and surprises, as well as countering the quantum arguments.

First of all, my experience of the apparent external physical reality (EPR) is very consistent over time, far more consistent than I could maintain in my own mind. The room I'm in seems to me very solid, detailed and unchanging except for the normal coherent changes with my movements and attention, and the passage of time. When I wake up each morning, the world seems just as I remember it from the previous day, even if I cannot describe all the details. To create and constantly maintain such consistency only in my mind would be far more than I feel capable of doing. What a waste of mental energy if it is not real!

Of course there are counter arguments. How do I know what I remember is what actually existed the last time I looked? Maybe my memories are being adjusted on the fly. And if my mind is incapable, then some sort of Universal Mind existing in the same mental reality would be more than capable of maintaining the illusion of consistency, which I only tap into from my smaller mind.

Next, there is the question of other minds. Unless I am a solipsist (believing mine is the only mind in existence), then MRT has to account for other people - or rather, other minds. They assume the other minds exist in the same mental reality universe. That is OK, albeit rather vague, but look at how these minds interact. If MRT is true, one would think telepathy would be the obvious way for minds to interact. However, that does not seem to be the case in our experience. Rather, we seem to need to convert thoughts into nerve impulses that control muscles and body parts to create speech, which then goes as sound waves to the other person's ears, to be converted to nerve impulses into his brain before becoming a communication. Interaction at a distance involves additional transducers and physical signal media, like telephones, computers, wireless and electrical circuits, etc. Why depend on such cumbersome, convoluted methods for mind-to-mind interaction if it isn't real? And what does "distance" even mean in a mental reality?  If all of this apparent physical reality is an illusion, how did it come about and why does it seem so real to each one of us?  Perhaps some demon mind is running the experiment, having better control of mental "space" than we have managed, and using it to fool us all?

When these two arguments are combined, they provide a third one: shared experiences. When two people sit down together, they can communicate sufficiently well to be sure that the EPR they experience is identical. The table between us is this colour, that material, an agreed size and shape, and so on, to an almost arbitrary level of detail. They can see, touch, hear and experience the same things and events, without unexplainable differences, aside from the obvious ones of precise location, which way they are each looking, and so on.  In an MRT world, how would that work? How could two minds "move" to meet together, see the world shift as they move, and then experience the same "reality" around them from slightly different, but compatible perspectives, all without prior collusion?  That is never explained, other than by some reference to the Universal Mind controlling everything; perhaps the same mad scientist or demon?

In philosophy, it is often useful to reflect on how children grow and develop in order to address deep questions. MRT has no problem with minds being immature or minds learning and maturing - that is what minds do.  But how does that apply to what children actually do while learning?  Almost all of their learning is based on interaction with the EPR, through touch, sight, movement, sound, etc. Despite parents' and teachers' best efforts, children do not learn much by direct, verbal communication. Nor do they soak up wisdom by osmosis from some Universal Mind.  And then there is the question of how such children come to exist? What is the mental reproduction process that seems to require physical interaction between two and only two different minds? While I haven't read a lot from them, MRT proponents would seem to provide little help there.

An interesting consideration is the concept of "surprise". All through life, unexpected things happen to us all. We stub our toe, we lose our keys, we find a long lost book, we have a surprise party, or an unexpected visit from a friend (or the police!), and so on.  If MRT is true, where are these surprises coming from?  I cannot be creating them myself or they would not be surprising.  One could argue that my subconscious is creating them, but what does that even mean in MRT theory?  Does my mind have purely mental "parts" that work together? The other answer would, again be the Universal Mind creating these situations for me.

The last point, regarding quantum physics, is somewhat different.  MRT people seem not to notice the irony of depending on the results of physics experiments done in the EPR as evidence that the EPR does not exist.  If MRT is all there is, then particles, waves and energy, not to mention all of physical reality, including physics itself, are illusory.  How can an illusion be used to prove its own non-existence?  I expect MRT has some explanation for this seeming contradiction, but at first blush, it looks like an odd approach.

As I see it, to be credible, MRT must fall back on some sort of Universal Mind, which to us would be indistinguishable from "God". This suggests that MRT is metaphysical at its core, and perhaps religious as well. That is OK as long as MRT people do not then try to debunk actual religions and other people's metaphysics.  Indeed, there are related theories that the EPR we experience, including ourselves, is a simulation at some god-like level. That may be conceivable, but it is not quite the same as MRT. In any case, personally I am going to stick with realism, trusting the existence of an EPR, as my view of reality.  And I suggest that MRT advocates operate 99% of the time as if they too accept EPR as the basis for their ongoing existence and experiences.

I did say the debate has been around for awhile. These few paragraphs will not settle it, of course, but it was fun exploring some aspects of the two competing views, and I now wonder, are there only two, or is there a third possibility?

Thursday, 19 November 2020

Climate Change Revisited

In my earlier post on anthropogenic global warming (AGW), I provided four sequential questions to ask about global warming, to better think about the issue.  I am pleased to have seen these same four questions raised by others since then, although I cannot claim to be their source.  This post is an extended update on the subject, including what I have learned since then, through reading IPCC documents, science publications, and several articles on the "other side" of the issue, as well as various web sites.  A good site to follow, that covers the science and multiple perspectives, is Watts Up With That.

I begin with an update on the four questions, with my current take on some answers:

1. Is the planet Earth warming?

Yes it is quite clear that there has been some warming, but just how much, and from which starting point remain uncertain. The planet appears to be warming slowly over the past century or more, by way of small increases, separated by level periods, or even occasional declines.  The amount of warming depends on who you ask and what year you choose for your baseline, but it seems to be about one degree (either Fahrenheit or Celsius depending on your perspective) at this point.  Few people deny this or claim there has been no warming at all.  Moreover, the arctic appears to be warming more than the rest of the land, which in turn has warmed somewhat more than the oceans.  

As a caution however, a century ago the world was coming out of a cool spell, known as the "little ice age", when the climate was decidedly sub optimal, and there have been previous warm and cold periods.  For example, 12,000 years ago we were in an ice age. Indeed, over geological time, the Earth has been much warmer and much colder at various times in the past.  The climate has always been changing and there is no such thing as a stable climate. The bigger question is, how much warming will there be in the future? And therein lies the controversy.

2. Are we causing the warming?

Here too, the answer appears to be "yes", human activities are very likely causing some of the temperature rise.  My initial guess was a cheat of 50 +/- 40%, and the Intergovernmental Panel on Climate Change (IPCC) agrees that we are the cause of at least half of it, thereby allowing that other factors surely play a role.  Other respectable sources suggest less than 50%.  Few people claim no human cause for the warming, while some claim we are causing almost all of it.  For now I'll stick with half and maybe tighten up the uncertainty a bit, say 50 +/-30%.  Mind you, this alone says very little about future warming possibilities.  In addition to burning fossil fuels and the increasing carbon dioxide (CO2) concentration in the atmosphere, there are other factors influencing global temperatures and regional climates: deforestation, solar shifts, ocean currents, urban sprawl, cloud cover, etc.  None of the models in use today accurately capture all the influences. Indeed, we do not even understand some of relations.

3. Is the warming bad?

This, of course, is where we shift from "global warming" to "climate change", with all the added confusion and uncertainty that entails.  Here too we get into the difficulties and disagreements driving the controversy.  Any change to the past climate in some regions will be bad in some ways, for some people or ecosystems, but it is tricky to nail down any of the supposed effects for certain.  The IPCC focuses on the assumed negative consequences of rising CO2 levels: melting ice and permafrost, rising sea levels, warmer seasons, shifting biomes, etc.  Despite a lot of hype in the media however, even the IPCC does not find much evidence for strong effects on rainfall, drought, storms and other weather extremes.

While most public reports point to the negative effects of increasing CO2 concentration and rising temperatures, fewer point to the clear benefits. Increased CO2 has led to a significant greening of the world: more leaves on trees, faster crop growth, longer growing seasons, etc.  Plants need and benefit from CO2 and the more of it in the air, the more they will soak up, thereby storing more "carbon".  I will doubtless get blasted by the "consensus" crowd for saying this, but shorter winters and warmer growing seasons should be good news for northern climes such as Canada.  In general, one should look for both pros and cons to assess any change, and not look only at the negative effects.

One of the bad effects most often mentioned is sea level rise, but that has been grossly overstated.  Sea level has been rising ever since the last ice age ended. The average rate over the past century was something like 1.4 to 1.8 mm per year, depending who you ask.  Even if that increased to 3 mm/yr (unlikely), the rise would be only about eight inches by 2100. This would surely cause additional problems for low-lying shores, but it is hardly a global catastrophe, or the end of civilization as we know it, and there is lots of time to adapt. 

This points to what is missing in the above question: the projections into the future. Almost all of the supposed negative consequences of climate change arise from uncertain models of the effects of global warming on the planet, ecosystems and human activity.  Those models in turn are based on projections of temperature rise 60 or 100 years or more into the future, which come out of other models for the Earth's climate. Given that climate models have not been able to account for changes over even the past twenty years, to rely on them to predict a century ahead seems risky at best.  And modelling supposed climate change consequences based on those projections just multiplies the uncertainties.

Given that the worst supposed effects of climate change are not projected to occur for many decades, an unbiased reader can perhaps see why so many people are leery of directing massive public policy changes on the basis of the worst-case published results of these same models.

4. Can we do anything about it?

Here I would like to split the question in two: physical possibility, and political likelihood. First, is it even physically possible for humans to change the climate significantly? The climate has changed - sometimes a lot (e.g. the ice ages) - without human causation for eons, suggesting that there are more important factors beyond our control.  However, if 50% of recent warming has indeed been caused by humans, then in principle we have some control over future warming and the resulting climatic changes.  According to global warming theory, greatly reducing or eliminating CO2 emissions - primarily from burning fossil fuels - would be the necessary step. 

This is a reductionist approach, assuming that humanity has a climate control knob called "CO2 emissions" that we can readily adjust; the Earth's thermostat as it were. Stating it this baldly and simplistically underscores the fact that the "climate change" issue goes well beyond CO2 emissions and the things we can control.  Nevertheless, it may, in principle, be possible to exercise some degree of "control" over future warming by drastically changing our use of fossil fuels.

The second part asks whether humanity can work together to achieve this goal, even in part?  Is there the global political will and wherewithal to drastically reduce coal, oil and gas usage for our usual purposes of industry, transportation, home heating, etc.?  Based on the track record of the past 30 or more years, the answer appears to be, "no, we cannot".  How many Kyoto accords, Paris agreements and other major international plans have come and gone with little to show for them?  When one major player (the USA) has backed out of Paris, and the other (China) declares it will only begin reducing  CO2 in 2030, even as it builds more coal-fired power plants each year, it seems unlikely that major decreases in CO2 are likely to be achieved any time soon, notwithstanding all the talk, planning, and insistence from various quarters. 

It is true that there have been small improvements in some jurisdictions, and there are ways to convert some CO2 producers to reduced-emission energy sources.  Wind and solar power are touted as the solution, but have their own problems; e.g. the need for large scale energy storage.  And changing from coal and oil to natural gas in many situations reduces the net CO2 emissions.  Despite the wishful thinking, however, gas, oil, and even coal will be with us for many decades to come, especially since we cannot ethically deny their use by developing countries to get their populations up to developed-world levels of health, education, infrastructure, etc. 

Perhaps the most effective short-term initiative would be efficiency: finding better ways to do more with less energy.  Along those lines, it should be possible to encourage people to cut down on fossil fuel use via smaller cars, well-insulated houses, working from home, less air travel, fewer gas-guzzling "toys", etc.  There are some trends in this direction, and some countries and cities have been able to make small reductions in their CO2 emissions.  But wholesale cuts beyond perhaps 20% over the next decade or so seem highly unlikely (barring new pandemics).  To reduce CO2 emissions by 50% or more would require severe changes in how we live, work, play and run most of our human activities.  Indeed, despite all the virtue signalling, when push comes to shove, "climate change" is not very high on the public's priority list.

Further Discussions:

Based on these four questions and my answers, a fifth question now seems necessary: Should we try to do something about climate change?  Some shrill voices insist that we must do everything we possibly can immediately to save the planet.  Others claim that the high cost of the demanded changes would be worse than the likely effects of climate change for the realistically foreseeable future.  The former voices then call the latter ones "deniers", and in return, the latter may refer to the former people as "alarmists".  As usual, prudence and reason suggest a reality somewhere between these extremes.

Part of the answer to this new question would be to seriously study the pros and cons of a warmer climate, realizing the uncertainties and biases inherent in all the models, and leaving aside any prior judgements on the matter.  Part of that in turn, is to come up with realistic calculations of the likely rise in CO2 over the next few decades, based on reasonable assumptions.  Then a range of approaches to estimating the effect of increased CO2 on the global temperature can be taken.  Of course both these approaches have been pursued, but there are other players than the IPCC who come to quite different conclusions.  Rather than circling the wagons and calling each other names, scientists should humbly look at ALL arguments and assess all data fairly, and then predict a realistic range of warming into the future, along with a variety of cost-benefit analyses regarding its effects.  In this vein, it is telling that previously warm periods, for example, Roman (1 to 300 AD) and medieval (800 to 1200 AD) times, were known as climate "optimums", in the sense that the world seemed better for civilization when it was warmer.

In the meantime, I expect that most people would agree to pursue research and development of ways to mitigate and adapt to likely changes in regional weather patterns and temperatures that realistically might happen over the next say, 20 or 30 years.  These analyses could look at further efficiency improvements, reasonable tax and incentive approaches, practical energy storage processes, realistic carbon capture and sequestration options, safe nuclear energy, and probably many other ways to incrementally reduce fossil fuel usage.  After all, eventually coal and oil will truly run out and mankind will need to have other large reliable energy sources in hand.  Thus, I support a shift away from fossil fuels, but realistically expect that to take several decades at least.

The climate change bandwagon has pushed ahead by referring to sceptics as "deniers", harping up the IPPC reports, getting children and schools riled up, and getting government lip service in line.  In 2010-2019 it seemed to be the biggest topic for the United Nations, all Greens, various liberal governments, the news media, Hollywood, many science agencies, etc.  Such was the “consensus”.  Most of the public attention was thereby focused on the IPCC reports and the climate change warnings that regularly come out stating we have only 12 or 10, or even 5 years left to "save the planet".  These groups and opinions wag the finger at the "deniers" and any governments too slow in acting seriously about "climate change" despite the supposed "settled scientific consensus" on the subject.  However, one has to look beyond government virtue signalling and media hype to hear the other side of the controversy in order to get a balanced view of things.  And there certainly is another side.

A View From the Other Side:

Much less has been published about the over-the-top climate change evangelists, sometimes referred to as “alarmists” for overstating the issues and hyping up the science.  Therefore, I would next like to turn the tables and take a closer look at them and how their "sky is falling" message has skewed reasonable discussion on the topic of CO2 emissions, global warming, climate change, and their likely effects.  The following are a few of the concerns I have seen raised about the alarmist position, which act to undermine their arguments and the whole climate change crisis story:

1. The IPCC is fundamentally biased in its mandate and approach: to find evidence for anthropogenic global warming and to explore its negative effects.  It is assumed that CO2 is the primary cause of recent warming and little effort is spent studying other causes.  Meanwhile, all the effects of climate change are assumed to be negative whereas there are clear benefits of increased CO2 and a warmer planet.  A balanced (scientific) approach would include evidence, analyses, models and opinions from all sides.

2. The climate change warnings arrive with vague fears for the (mostly distant) future, with unspecified "tipping points", apocalyptic worries, and shrill demands for immediate major changes to global civilization.  These come as hyped interpretations of selected modelling reports.  Other, more moderate voices are purposely squelched, ignored, or drowned out by alarmist shouting. 

3. I have seen credible, persistent and detailed reports of selected or even doctored data used as evidence for AGW and its related effects. Biased assumptions, suspicious   "corrections" to past data, and skewed analyses are common.  Even choosing the baseline or starting point for statements about CO2 concentration, average global temperature and the supposed effects of AGW are not accepted by everyone.  And few ever explain what temperature would be "ideal" for the world.  When did we ever have an optimum and stable climate?  Can we expect the Earth's climate to remain the same forever according to human wishes? 

4. The supposed "consensus" and "settled science" about climate change are simply not true.  The oft-mentioned 97% consensus comes from from a highly selective and unrepresentative sample of views.  Claims of scientific “consensus” as an argument should be suspicious for any complex subject.  For AGW and climate change, it is simply false, yet the claim continues to be made, despite repeated correction.

5. Some alarmists misrepresent or dismiss past climate changes - both positive and negative shifts in global temperature - as well as their effects (both positive and negative).  Just think of the infamous "hockey stick" graph that supposedly made global warming seem unprecedented, yet settled science, but which was later shown to include a built-in warming trend, even when presented with random data.

6. The various climate models over the past 20 or 30 years have consistently produced spectacularly failed projections, predicting temperature increases far above those actually measured.  Clearly the models assume an unrealistically strong connection between CO2 concentration and radiant heat balance at Earth's surface.  If they are wrong over 20 years, how can their 60 to 100 year projections be taken seriously?  Yet we are told we absolutely must do everything demanded to prevent their worst-case projected outcomes and thereby "save the planet".

7. The overreaching demands for political and economic upheaval, supposedly essential to prevent climate catastrophe are presented with little supporting analysis to back them up.  Surely dire predictions and demands for civilizational reset require solid, generally accepted evidence, and not just pleas to failed models and the precautionary principle.  It is telling that those demands look a lot like socialist utopian dreaming.

8. The demands to stop using fossil fuels arrive with wholly unrealistic hopes and expectations (dare I say dreams?) for alternative energy sources in the near term.  Any reasonable look at where mankind gets its energy clearly shows fossil fuels will be needed for many decades yet, especially in developing countries.  Without low-cost, reliable and massive energy storage technology, wind and solar energy cannot replace fossil fuels in most applications.

9. Alarmists are spreading irrational fear among people, and especially children, via schools, the mainstream and social media, Hollywood, etc.  See for example, Al Gore’s movie "An Inconvenient Truth" with its unfounded extreme predictions, or the shrill statements of, "only ten years to save the world" (repeated every decade or so).  Most of this is simply unsupported, "the sky is falling" nonsense.  Climate change as an existential threat?  I have not read anything meaningful pointing to that as a serious possibility.  Please stop the fearmongering, then we can talk.

10. Finally, there are the hypocritical agreements, statements and spokespersons who do not walk the talk they insist the rest of us accept.  Wealthy people flying personal jets lecture the middle class on turning down thermostats and using public transit.  Public figures hype sea level rise, while buying ocean-front properties.  If you cannot practise what you preach, stop demanding it of the rest of us.

Aspects like these make it hard to trust the supposed “settled science” that the standard narrative insists on.  If there is solid evidence that global warming is caused by us and is truly bad, then explain the science and logic and deal with counter arguments fairly.  Don't hide behind a trumped up “consensus”, with all the attendant hype and fear.  If there truly is a serious risk to the world and humanity 80 or 100 years from now, then we can plan realistic actions to minimize or mitigate the worst effects.  Don't just preach global climate doom and then make unreasonable demands.  I note in passing that the people most worried about potential AGW effects 100 years from now, often do not seem at all concerned about the reality of economic doom from ever-increasing public debt that will assuredly weigh down our children and grandchildren.

Finally, there are entirely reasonable things we can do individually and together to reduce our “carbon footprint”: less travel, smaller houses and cars, walk or bike when possible, work from home, improve energy efficiency, reduce waste, live within our means, encourage modest increases in renewable energy (with energy storage tech), help developing nations form stable governments and economies, stop enabling and fighting wars, stop cutting down rainforests and polluting the oceans, grow more plants in and around cities, adopt safe nuclear energy, and so on and on.  There is a long list of things people can do to reduce the need for fossil fuels, improve CO2 capture in plants, and minimize our individual and societal impacts on the planet. 

In conclusion, the planet Earth is indeed warming somewhat at present, and the climate is changing for various partially understood reasons.  There will doubtless be some moderate negative impacts in certain regions, but this is not a human existential crisis.  Surely there is a sane middle ground between denier and alarmist that most people can agree on, and accept as a starting point? As time goes on, we will learn more about the climate and be able to do more to adapt to or mitigate the impacts of any changes, however, there is no need to try to do impossible things immediately to address a problem that potentially might get bad in a century or so.

Tuesday, 18 August 2020

Some COVID-19 Analyses

I don't usually blog about current events or issues in the news, but COVID-19 is such a big thing this year that I cannot resist throwing my thoughts into the fray.  So here is what I analysed and concluded, based on analysis of the Ontario, Canada data, lately taken from their official COVID-19 data web page:

My interest in analysing the pandemic began in early April with the initial published data on cases and deaths.  It seemed to me that at the time, the deaths per case rate (then around 6%) was higher than the officially published estimates (1 to 4%), and was slowly rising from week to week.  Of course I realized that was to be expected since, at any point, the accumulating deaths would lag the accumulating cases by about a week because it would take about seven days for someone to die from the disease after being diagnosed.

Instead, I then looked at the number of deaths and the number of "resolved" cases -- the survivors -- which may be lagging in the opposite way, it taking longer to show that someone is no longer ill than it takes to die.  That number has remained around 9% of resolved cases (survivors plus deaths) every week I updated the numbers.  Adding to those results the estimated 30% of "asymptomatic" cases -- cases undetected because the person does not feel sick (and does not die) -- and the overall fatality rate drops to something between 4 and 6%, still above the WHO and international estimates.

I started looking into these results and discrepancies, and quickly hit on the age of the person as the principal factor in determining risk of death.  The graphs of Ontario deaths by decadal age range, normalized to a population of 100,000 showed a distinct exponential curve shape, so I took their data and plotted it on a logarithmic scale.  I was shocked to find how precise the exponential trend was.  I redid this analysis every two weeks and in June, got the results shown in the following graph.

Here I have plotted three trends by age group, using an X-Y plot instead of the usual bar chart to allow further analysis.  Each age group is therefore one decade of people; e.g. the 30 to 39 year datum is shown as age 35.  I plot the number of cases up to June 8 per 100,000 population in that age range for Ontario, by age group, from 0-9 years through 90+ years old (blue squares). More description about that curve later.

The orange diamonds plot the number of deaths per 100,000 population up to the same date.  It was this straight line that first intrigued me -- an almost perfect exponential relationship!  However, since the number of deaths continue to accumulate over time, I decided to further normalize the data, by dividing the orange diamond data by the average risk of death for the entire population, to get the yellow triangles, which represent the relative risk of death (percentage) by age, which should not change over time.

The yellow triangles are, of course, also a straight line, and I have included the trend line as an exponential equation.  The R-squared value indicates how good the fit is over eight orders of magnitude, from 20 to 95 years old.  (Below 20 years old, the numbers are estimates since, at that date, there had been no deaths in that age range.)  I imagine such close a fit is almost unheard of in medical and disease statistics -- a fascinating discovery!

To better explain the yellow trend line, the average relative risk of death is 1.00 by definition, and that occurs around age 67 years old.  Older people are at more risk, as everyone knows, while younger folk are at reduced risk.  However, nowhere else have I seen it shown how important this age factor is, and over such a wide range.  Indeed, between age 20 and age 95, the risk of death from this disease doubles every 5.77 years older you are!  An 85 year old is therefore over 450X as likely to die from COVID-19 as a 35 year old, all other factors being similar!

That is a huge difference, yet rarely talked about.  After finding these results, I sent them to the Ontario public health people, my elected member of the provincial parliament (MPP), and the local health authorities.  I figured they would want to know these results and perhaps apply them to choose public policy going forward.  I heard nothing back, so I wrote a letter with the results to my local community paper.  The letter got published and I got a couple of private responses, but again, no public, or broader-media recognition.  I guess I am not an "expert" so no one pays me any attention.

There are some further things to note in this data.  For the oldest Ontarians, those over 90 years old, the disease has been devastating.  Fully 35% -- more than a third -- of those who got this disease died!  That is comparable to the fatality rate for the black plague in medieval Europe.  This was reflected in the huge number of deaths seen in nursing homes or "long-term care" facilities in the early months of the pandemic, a black mark on Ontario and how we care for our oldest citizens.

If applied, these results could have an important influence on public health policy.  Clearly, people over 70 need to be kept safe from contact with infected people, and monitored closely.  This is well known but never quantified as shown here.  On the other hand, people under 50 years old have a very low risk of death, especially those without underlying health conditions.  Perhaps they could get back to work with minimal constraints?  Even more, with few cases and almost no deaths for people under 20 years old (read "students"), there is almost negligible risk if they are otherwise healthy, so re-opening schools with few constraints looks feasible.

The true danger lies in mixing the young with the old: elementary teachers nearing retirement, retired folk driving school buses, kids living with their grandparents, young personal-care workers serving in nursing homes, etc.  There would have to be some careful policies put in place to avoid contagion in those, relatively few situations.  People between 50 and 70 could decide for themselves what risks they are willing to take, based on their own home, work, life, and health situations.

Such an approach would go a long way to re-opening economies, and thereby minimizing the non-health impacts of the pandemic.  Governments in various places seem to be headed in this direction, although hesitantly and still with severe constraints on the young about distancing and masks.  Despite ongoing hype about increasing "cases", worries about the fall influenza, and comparisons among different countries' and states' experiences, there does not seem to be general recognition of the results I have graphed here.

I continued to track the Ontario COVID-19 numbers to see how the results would change over time. A month after the above plot I redid the analysis and got the following graphs.  As you can see, they are very similar.  The number of cases and deaths per 100,000 people has gone up slightly as you would expect, but the overall shapes have remained the same.  There was one death of a child under ten, which skews the bottom end in a non-statistically relevant way.  For the "relative risk of death" curve (green triangles in this graph), between ages 20 and 95, the results are almost identical, fitting the same exponential equation as a month earlier.  The doubling time for the death risk is also almost identical at 5.85 years. Since July there have been fewer new cases to add and even fewer deaths in Ontario, so the results are essentially unchanged as of this writing.

One further note about the top curve (blue squares). between 20 and 80 years old, this curve is almost flat, with about 250 cases per 100,000 population. This suggests that COVID-19 is just as easy to catch at any age -- an equal opportunity disease -- and that it is the fatality that varies with age, not the contagiousness.  However, both ends of the curve are different.  Below age 20, there are fewer cases found per 100,000 people.  This probably reflects that fact that young people don't generally get sick from this corona virus, so many infected people would not be tested to become "cases".  One could, in principle, look at the difference between the data points and the 250 average to estimate what percentage of people under 20 had the disease without being tested, at least in comparison to the same percentage for older adults (unknown, but estimated around 30%).

The top end of the curve is more troubling.  More people per 100,000 over 80 years old got this disease than those under 80, and it is even worse for those over 90.  This may have several causes, but surely reflects the rapid spread of the disease through unprepared nursing homes as we saw in April and May.  Another possibility is that some of those folk may have actually died from other causes -- they were in nursing homes after all -- and were then found to have COVID-19, and so were counted as having died from it rather than just with it.

I have stopped analysing COVID-19 cases and deaths in Ontario now that they have levelled off, but I wanted to capture all these thoughts and results, if only for posterity.  If you are reading this, you can compare the results where you are to see if they mirror Ontario's experiences so far.  These results may also help you decide how worried you should be about this virus, depending on your own age and that of your loved ones.  If it merely helps some parents feel better about sending their kids back to school, then it has been a useful exercise.

2021 Update

 I dug out the Ontario cumulative case and death numbers up to January 25, 2021 and repeated the same analysis.  In the following graph, I only include the percent risk of death from COVID. That is, for each age group, the percentage of cases over the past year who died. The exponential trend is still clear, albeit not quite as precise.  The risk doubling time is still 5.8 years of age, and people over 90 years old have a 30% chance of dying if they get the disease, slightly lower than reported above. This may reflect better care being taken in long-term care facilities?

The average risk of death has dropped considerably to about 2.5%. That is largely because it is mostly younger people who are getting COVID-19 now, but the risk to young people is still very low, less than the death risk from the flu for people under 40 years old!

With vaccines being widely administered over the next months, one hopes the overall number of cases and deaths will stop increasing everywhere. As the vaccines are first given to the oldest and most at risk populations, one might expect this curve to shift slightly, but I hope there will be many fewer deaths going forward than over the past ten months. If so, then this curve will not change significantly.