Having seen my brother (Pastor Mike) become ever more unhinged, and his use of "evil", "sin" and "Devil" multiply with his delusions, it is time to get a grip. Is he talking-writing of actual, objective realities, or blowing gaseous emissions out of his mouth (and mind) that bear no semblance to the real world?
In truth, the use of the word “evil” is freighted with superstitious baggage, of little use in a rational –technological age. It presumes origination from “a negative supernatural force” or “Satan”. It overly complicates the issue while unnecessarily adding theoretical existences. We already know in this case that brain structures (e.g. amygdala, reticular formation etc.) can account for all atavistic behaviors from misdirected lust, to baby killing to mass murder or genocide. One need not invent a supernatural special being or super Devil to account for them!
About a year ago, I also took Wendy Kaminer to task in an issue of Free Inquiry (‘Religious vs. Secular Concepts; April/May 2007, p. 65), for an earlier piece in which she (a claimed secularist) used the loaded terms “sin” and “evil”. Kaminer replied in a short note to my letter , basically averring she had no intention of altering her “attachment to moral categories of good and evil.” This is her prerogative and right, of course, but doesn’t alter my own point one iota. That if Kaminer (or anyone else) embraces such attachment then she is more rightly a religionist and not a secularist. Secular people refrain from using religious words, labels, concepts or language in the sense of positively incorporating them into a secular Zeitgeist..
But let us return to my pastor brother's contentions, and in particular his question: ‘Can an atheist deny the existence of evil?’
I maintain that denial of “evil” is not the issue, but primitive language use is. Thus, “evil” is an antiquated and redundant term since what people refer to as “evil” is easily explainable in terms of brain evolution. Thus, Homo Sapiens is fundamentally an animal species with a host of animal/primitive instincts residing in its ancient brain or paleocortex.
Meanwhile, the paleocortex sits evolutionarily beneath the more evolved mesocortex and neocortex, the latter of which crafts concepts and language. One clever person has compared this tri-partite structure to a car design welding a Lamborghini to a Model T Ford chassis, with a 1957 Chevy engine to power the Lamborghini.
There is much evidence that the aggregate of human behavior will get progressively worse as the complexity inherent in technological and globalized societies increases, but brain evolution is unable to keep pace with it. Basically, we are a species with the capability of making nuclear weapons and intercontinental missiles – but with Cro-Magnon brains – and a swatch of reptilian tendencies.
Indeed, the mixed brain design, in terms of adaptability to modern society, is already theorized as one major cause of depression and mental illness in modern society (e.g. The Noonday Demon, Chapter 11, ‘Evolution’, p 401)
The behavior resulting from this hybrid brain is bound to be mixed, reflecting the fact that we literally have three “brains” contending for emergence in one cranium. Behavior will therefore range from the most selfless acts (not to mention creative masterpieces) to savagery, carnal lust run amuck and addictions that paralyze purpose.
The mistake of the religionist is to associate the first mode of behavior with being “human” and not the latter. In effect, disowning most of the possible behaviors of which humans are capable.- and hence nine-tenths of what makes us what we are. Worse, not only disowning these behaviors but ascribing them to some antagonistic dark or negative supernatural force (“Satan”) thereby making them into a religious abstraction.
The neocortex then goes into over-drive, propelled by its ability to craft words for which no correspondents may exist in reality. Suddenly, our “souls” are at risk of being “lost to Satan” who will then fry us in “Hell”. In effect, the religionist’s higher brain centers divide reality into forces of darkness and light, just like the ancient Manicheans.
As the divide grows and persists, certain behaviorally idealistic expectations come to the fore, and a mass of negative or primitive actions is relegated to “evil”. Humans tuned in to this Zeitgeist, which is soon circulated everywhere, being to suppress all behaviors that they regard as defective or “sinful”. They don’t realize or appreciate that humans are risen apes, and not “fallen angels”.
Are we all “sinners” as Pastor Mike claims? No, we’re an animal species saddled with a tri-partite brain whose higher centers often become self aware of the gulf between the base, atavistic and primitive behaviors (emanating from the reptilian brain) and the ideal, non-atavistic behavior conceived by the neocortex. The neocortical language centers then craft the term “sin” to depict the gulf between one and the other.
In this context, the concept of “sin” makes eminent sense. Sin emerges as the label placed on specific brands and forms of “evil”. In reality, “Sin” itself is predicated on an exaggerated importance of humans in the universe. Thus, it elevates (albeit in a perverse way) the importance of humans in an otherwise meaningless cosmos. With “sin” the human has at least the potential of offending his deity – thereby getting its attention – as opposed to being relegated to the status of a cosmic “roach” (which any advanced alien sentience would regard us).
“Sin” then is localized and reactive behavior at the personal, individual level. “Sin” impinges on and affects the deity that so many believe in. Take away the deity, and sin loses its allure and quickly becomes redundant. How can there be “sin” if there is no deity to offend or to notice “sin”? To tote up all the little “black marks” in its “book of future judgment”.
“The Devil” or “Shaitan” is simply the projection of the most primitive brain imperatives onto the external world. And yes, this imperative (which I will soon get to in more detail in Part II) is capable of mass murder as well as genocides. A supernatural Satan need not be invoked here, only the ancient brain of reptiles – acting collectively – aided and abetted by a newly perverted neocortex, which now does the reptile brain’s bidding, as opposed to attempting to halt it.
The more real and present danger inheres in zealots and extremist religionists projecting their Satanic delusions on fellow humans, and thereby demonizing them to convert them into the most debased and vile outcasts. Thus does Pastor Mike refer to atheists as "agents of Satan" and "Satan's disciples" - as if the ability to merely question rigid or uncritical adherence to a faith qualifes as a demonic attribute.
Thursday, February 28, 2008
Wednesday, February 13, 2008
Getting to Know the Sun (II)
Sunspots, like weather systems (which, incidentally arise from solar heating effects) are not subject to a high-order accuracy of predictions. Unlike billiard balls and planets, whose positions can be predicted to near perfection - sunspots are large thermodynamic and magnetic systems. To be truthful - solar researchers at this stage are not even sure of the interplay between sunspot magnetism and thermodynamics, far less predicting how they combine to yield flares or other effects (sprays, surges, prominences). The precise role of each of these phenomena to each other is also an ongoing source of contention between solar researchers.[1]
Consider the sunspot itself. It appears to be just a simple dark blemish on the solar surface, or photosphere. In fact, the darkness is purely an illusion resulting from its lower temperature (about 6,000 F) compared to the surrounding photosphere (11,000 F). The sunspot's "single" state is also somewhat illusory - since nearly all sunspots occur in pairs of differing polarity, like the north and south poles of a magnet. (Solar astronomers call them "plus" and "minus" poles).
A question of long standing seems to be how a cooler gas[2] can be immersed in a much hotter gas without itself reaching a higher temperature. This seems to defy one of the laws of thermodynamics. Investigations have only recently disclosed the underlying reason: the powerful magnetic fields - up to 5,000 times stronger than the Earth's. These incredibly powerful magnetic fields trap the cooler gases inside a confined region (tube) which actually "floats" on the hotter, less dense medium of the photosphere.
In the photo (via link) below is a typical, large sunspot pair, as captured in a catadioptric telescope with solar filter. The image embodies how spots are (currently) theorized to be at opposite ends of a "magnetic tube", spanning opposite magnetic polarities. In this case the leader spot (lower right) is at one end of the tube, and the (partly bifurcated) followe (upper left) is at the other.
http://groups.msn.com/PlanetStahl/mathphysics.msnw?action=ShowPhoto&PhotoID=41
From the photo, the leader spot is at the positive polarity end of the magnetic loop containing the cooler gases, while the followe is at the negative polarity end. The key aspect to note in the above is that sunspots are pictured as sections of magnetic loops seen in projection. The darkest regions occur where the trapped gases are coolest and the magnetic fields strongest. Sunspots themselves display two distinct regions: a dark, central umbra and an outer, lighter penumbra - with the latter at the (somewhat) higher temperature.
Why are sunspots so important? For one thing, they may signify that the Sun is a variable star - or at least not as well-behaved as humans surmise. For example, if the so-called "Maunder Minimum" is a genuine effect, then the reduced numbers of sunspots may well have ushered in the "little ice age" from 1645-1715. And if a "little ice age" can be ushered in by sunspots (or rather their absence) then perhaps a major ice age could be. In any case, the answer won't be found unless sunspots are studied closely, to reveal any long term periodicity in their behavior. (Currently, a new consensus is emerging that no new ice ages will occur once the carbon dioxide concentration exceeds 450 parts per million - which may happen in the next fifty years)
As it is, astronomers know that the Sun exhibits an 11-year average sunspot cycle. This means that every eleven years - on average, sunspot numbers reach a peak - what is called the "sunspot maximum". Superimposed on this is a 22-year cycle, for reversal of magnetic polarities to occur in the "leading" spot. To fix ideas, consider again the photo above: Then the "leader" spot and the "follower" will exchange polarities in the next cycle, assuming that their orientation is in the direction of the Sun's rotation (east to west). The 22-year cycle means that 22 years (again, on average) must elapse before leader spots again have negative polarities at sunspot maximum. (In the intervening, or 11-year maximum, the leaders will all have positive polarity).
For some reason, very large sunspots with "complex" magnetic structures(that is, multiple +/- polarities in the same sunspot)can become unstable and given rise to extremely violent flares. This happened in August, 1972- with a giant flare hurling lethal protons at the Earth that would have killed any astronauts. It also occurred in March, 1989, when a giant sunspot group went unstable and precipitated the flare which downed the Ottawa power grid.
A 1992 movie with Charlton Heston, entitled Solar Crisis, depicted a future time in which the Earth is threatened by an impending "mega" flare that is forecast to tear away the atmosphere and shower deadly radiation on everything. Could such a fantastic flare actually occur - and could it be predicted as accurately as in the movie? This is doubtful on both counts.
For one thing, the energy of flares is limited by how much "free" (extractable) energy can be stored in magnetic tubes. A good analogy is a rubber band. If a rubber band is wound up over and over it gains free potential energy (available for future motion). Release it now and it will rapidly twist apart to its original state. Magnetic tubes on the Sun do something very similar. They are twisted up by the motions of the Sun's turbulent surface[3] - and store free magnetic energy as they twist. The more twisted they are, the more free magnetic energy they acquire - to power flares, and the particle bursts that accompany flares.
Flare energy is limited because: 1- there is a limit to the size a magnetic tube can attain, 2- there is a limit to how much twist a tube can acquire. Each of these limits the amount of total magnetic energy available for release. On that basis, it is unlikely that humans will ever see flares greater than those which occurred in August, 1972 and March, 1989. Obviously, if the Sun is a variable star - its physical conditions could change. One of these conditions is its rate of "differential" rotation[4] , which is believed to be responsible for the origin of sunspot magnetic fields. On that assumption, a higher rate of differential rotation could portend much more violent flares, precisely because magnetic tubes can acquire stronger magnetic fields (greater twist).
A much more credible risk from the Sun would be an inherent variability leading to temperature differences, and weather changes on Earth. At the present time, all the evidence indicates that whatever major solar variability exists is on a very long time scale, say ten thousand years. However, as seen earlier, there is nothing to rule out shorter term variability being superimposed on the longer term. In effect, the Sun could very well undergo smaller percentage changes in its energy output over smaller time scales - say 100 years or less[5]. The only way to determine if short term variability exists is to have solar satellites in place for detailed observations over extended times. At the present time, such satellites are not in any budget. Indeed, the last major solar satellite effort was the "Solar Max", which is now defunct. The SOT, or Solar Optical Telescope, was to be launched in 1985-86, but that was killed in a single budget cut - much to the consternation of solar researchers such as myself.
If advanced extraterrestrials were to pay us a visit, they would probably be astounded at a so-called intelligent species that sends all sorts of satellites and vehicles into apace - none of which is dedicated to continuously observing the home planet's nearest star! I would surmise that a truly intelligent species would place solar observations (e.g. of its own star) as having the highest priority of any space-based research - certainly over space shuttles, planetary probes and spy satellites. There wouldn't be any mystery to a solar priority, since after all the Sun is the 'hub of life' for all living organisms anywhere in the solar system. If the Sun's nuclear reactions 'turned off' for just a day[6] - all life on Earth would be frozen out of existence before the Sun's nuclear furnace switched on again. In other words, for all their technological prowess, humans would not survive even a day without the benefit of the Sun's life giving warmth and light.
For a physical perspective, it is useful to regard the Earth as situated inside the Sun. Technically, this is accurate - since Earth is literally bathed in the "solar wind" - a rapidly moving, tenuous gas continuously cast off from the Sun's corona, or outermost atmosphere. Our total understanding promises to be significantly enhanced with the Ulysses spacecraft - which will include passes over the solar polar regions.[7]
We now understand that the Earth - and all the other planets, originated as hot 'globs' of gas spun off from the bloated infant Sun. As each of these gaseous globs separated, then cooled and assumed its own orbit, it carried away some of the Sun's rotational motion. The legacy of this 'planetary secession' is that the Sun now rotates much more slowly (about once in 27 days) than it did in that early epoch.
The ironic end of the story is that one day in the distant future, an aged and inflated 'red giant' Sun will reclaim most of its original pieces. No life of any form will survive since the Earth will effectively be engulfed. All records of human habitation will be completely obliterated in raging firestorms long before the planet itself is reduced to a cinder. If any single, cogent reason can be advanced to induce humans to colonize other worlds, this is it.
[1] This was also a source of controversy at the 75th AGU Conference mentioned in the earlier footnote. At the May 26th, 1994 Thursday morning session, for example, solar physicist Hal Zirin and space physicist A.J. Hundhausen totally disagreed on whether solar flares led to coronal mass ejections or the other way around. Zirin steadfastly maintained that flares caused the mass ejections, while Hundhausen just as strongly maintained the reverse was the more accurate hypothesis. Such stark disagreements actually show the glaring need for a higher spatial resolution for solar-observing instruments. At least this was the general consensus that emerged from the Space Weather sessions I attended.
[2] I am using the term "gas" here, but actually the Sun's material is plasma. A gas - like oxygen at room temperature, has all its electrons. A plasma, on the contrary, is missing one or more electrons because of the high temperature it is subjected to. We say it is "once ionized" (one electron lost) "twice ionized" and so on. The significance of electrons being lost is that the gas becomes electrically conducting. Thus, a hydrogen plasma in the Sun will conduct electrical currents.
[3] In fact, the Sun has no definite surface, because it is a gaseous body. The 'surface' usually referred to, is that from which visible light emanates: the photosphere ('light-sphere'). It is very dense relative to higher layers, and is where most of the turbulent motions occur that can twist magnetic tubes.
[4] Differential rotation applies to a rotating fluid or gas. It means that the rate of rotation depends on the position of a point on the surface. In the case of the Sun, the fastest rotation is at the lowest latitudes, near the equator.
[5] There are some who claim variability arises from external changes in the Earth's orbit, rather than from internal changes in the Sun. Most often, the "Milankovitch Effect" is mentioned - whereby the Earth supposedly makes significant orbital changes, leading to much higher or lower mean global temperatures - depending on whether it is much nearer or farther from the Sun. At the present time, the solar research community gives very little credence to the "Milankovitch Effect", since there is no compelling evidence that it is significant enough to affect climate.
[6] Of course, there would be a long delay between the 'turn off' and when it was noticed on Earth! The average time needed for photons in the Sun's core (where nuclear reactions occur) to filter to the solar surface and escape - is about 1 million years. Thus, if all nuclear reactions shut down today - then the Sun would only 'black out' in one million more years (on average).
[7] See the papers on Ulysses findings: Science: Vol.268, May 19, 1995.
Consider the sunspot itself. It appears to be just a simple dark blemish on the solar surface, or photosphere. In fact, the darkness is purely an illusion resulting from its lower temperature (about 6,000 F) compared to the surrounding photosphere (11,000 F). The sunspot's "single" state is also somewhat illusory - since nearly all sunspots occur in pairs of differing polarity, like the north and south poles of a magnet. (Solar astronomers call them "plus" and "minus" poles).
A question of long standing seems to be how a cooler gas[2] can be immersed in a much hotter gas without itself reaching a higher temperature. This seems to defy one of the laws of thermodynamics. Investigations have only recently disclosed the underlying reason: the powerful magnetic fields - up to 5,000 times stronger than the Earth's. These incredibly powerful magnetic fields trap the cooler gases inside a confined region (tube) which actually "floats" on the hotter, less dense medium of the photosphere.
In the photo (via link) below is a typical, large sunspot pair, as captured in a catadioptric telescope with solar filter. The image embodies how spots are (currently) theorized to be at opposite ends of a "magnetic tube", spanning opposite magnetic polarities. In this case the leader spot (lower right) is at one end of the tube, and the (partly bifurcated) followe (upper left) is at the other.
http://groups.msn.com/PlanetStahl/mathphysics.msnw?action=ShowPhoto&PhotoID=41
From the photo, the leader spot is at the positive polarity end of the magnetic loop containing the cooler gases, while the followe is at the negative polarity end. The key aspect to note in the above is that sunspots are pictured as sections of magnetic loops seen in projection. The darkest regions occur where the trapped gases are coolest and the magnetic fields strongest. Sunspots themselves display two distinct regions: a dark, central umbra and an outer, lighter penumbra - with the latter at the (somewhat) higher temperature.
Why are sunspots so important? For one thing, they may signify that the Sun is a variable star - or at least not as well-behaved as humans surmise. For example, if the so-called "Maunder Minimum" is a genuine effect, then the reduced numbers of sunspots may well have ushered in the "little ice age" from 1645-1715. And if a "little ice age" can be ushered in by sunspots (or rather their absence) then perhaps a major ice age could be. In any case, the answer won't be found unless sunspots are studied closely, to reveal any long term periodicity in their behavior. (Currently, a new consensus is emerging that no new ice ages will occur once the carbon dioxide concentration exceeds 450 parts per million - which may happen in the next fifty years)
As it is, astronomers know that the Sun exhibits an 11-year average sunspot cycle. This means that every eleven years - on average, sunspot numbers reach a peak - what is called the "sunspot maximum". Superimposed on this is a 22-year cycle, for reversal of magnetic polarities to occur in the "leading" spot. To fix ideas, consider again the photo above: Then the "leader" spot and the "follower" will exchange polarities in the next cycle, assuming that their orientation is in the direction of the Sun's rotation (east to west). The 22-year cycle means that 22 years (again, on average) must elapse before leader spots again have negative polarities at sunspot maximum. (In the intervening, or 11-year maximum, the leaders will all have positive polarity).
For some reason, very large sunspots with "complex" magnetic structures(that is, multiple +/- polarities in the same sunspot)can become unstable and given rise to extremely violent flares. This happened in August, 1972- with a giant flare hurling lethal protons at the Earth that would have killed any astronauts. It also occurred in March, 1989, when a giant sunspot group went unstable and precipitated the flare which downed the Ottawa power grid.
A 1992 movie with Charlton Heston, entitled Solar Crisis, depicted a future time in which the Earth is threatened by an impending "mega" flare that is forecast to tear away the atmosphere and shower deadly radiation on everything. Could such a fantastic flare actually occur - and could it be predicted as accurately as in the movie? This is doubtful on both counts.
For one thing, the energy of flares is limited by how much "free" (extractable) energy can be stored in magnetic tubes. A good analogy is a rubber band. If a rubber band is wound up over and over it gains free potential energy (available for future motion). Release it now and it will rapidly twist apart to its original state. Magnetic tubes on the Sun do something very similar. They are twisted up by the motions of the Sun's turbulent surface[3] - and store free magnetic energy as they twist. The more twisted they are, the more free magnetic energy they acquire - to power flares, and the particle bursts that accompany flares.
Flare energy is limited because: 1- there is a limit to the size a magnetic tube can attain, 2- there is a limit to how much twist a tube can acquire. Each of these limits the amount of total magnetic energy available for release. On that basis, it is unlikely that humans will ever see flares greater than those which occurred in August, 1972 and March, 1989. Obviously, if the Sun is a variable star - its physical conditions could change. One of these conditions is its rate of "differential" rotation[4] , which is believed to be responsible for the origin of sunspot magnetic fields. On that assumption, a higher rate of differential rotation could portend much more violent flares, precisely because magnetic tubes can acquire stronger magnetic fields (greater twist).
A much more credible risk from the Sun would be an inherent variability leading to temperature differences, and weather changes on Earth. At the present time, all the evidence indicates that whatever major solar variability exists is on a very long time scale, say ten thousand years. However, as seen earlier, there is nothing to rule out shorter term variability being superimposed on the longer term. In effect, the Sun could very well undergo smaller percentage changes in its energy output over smaller time scales - say 100 years or less[5]. The only way to determine if short term variability exists is to have solar satellites in place for detailed observations over extended times. At the present time, such satellites are not in any budget. Indeed, the last major solar satellite effort was the "Solar Max", which is now defunct. The SOT, or Solar Optical Telescope, was to be launched in 1985-86, but that was killed in a single budget cut - much to the consternation of solar researchers such as myself.
If advanced extraterrestrials were to pay us a visit, they would probably be astounded at a so-called intelligent species that sends all sorts of satellites and vehicles into apace - none of which is dedicated to continuously observing the home planet's nearest star! I would surmise that a truly intelligent species would place solar observations (e.g. of its own star) as having the highest priority of any space-based research - certainly over space shuttles, planetary probes and spy satellites. There wouldn't be any mystery to a solar priority, since after all the Sun is the 'hub of life' for all living organisms anywhere in the solar system. If the Sun's nuclear reactions 'turned off' for just a day[6] - all life on Earth would be frozen out of existence before the Sun's nuclear furnace switched on again. In other words, for all their technological prowess, humans would not survive even a day without the benefit of the Sun's life giving warmth and light.
For a physical perspective, it is useful to regard the Earth as situated inside the Sun. Technically, this is accurate - since Earth is literally bathed in the "solar wind" - a rapidly moving, tenuous gas continuously cast off from the Sun's corona, or outermost atmosphere. Our total understanding promises to be significantly enhanced with the Ulysses spacecraft - which will include passes over the solar polar regions.[7]
We now understand that the Earth - and all the other planets, originated as hot 'globs' of gas spun off from the bloated infant Sun. As each of these gaseous globs separated, then cooled and assumed its own orbit, it carried away some of the Sun's rotational motion. The legacy of this 'planetary secession' is that the Sun now rotates much more slowly (about once in 27 days) than it did in that early epoch.
The ironic end of the story is that one day in the distant future, an aged and inflated 'red giant' Sun will reclaim most of its original pieces. No life of any form will survive since the Earth will effectively be engulfed. All records of human habitation will be completely obliterated in raging firestorms long before the planet itself is reduced to a cinder. If any single, cogent reason can be advanced to induce humans to colonize other worlds, this is it.
[1] This was also a source of controversy at the 75th AGU Conference mentioned in the earlier footnote. At the May 26th, 1994 Thursday morning session, for example, solar physicist Hal Zirin and space physicist A.J. Hundhausen totally disagreed on whether solar flares led to coronal mass ejections or the other way around. Zirin steadfastly maintained that flares caused the mass ejections, while Hundhausen just as strongly maintained the reverse was the more accurate hypothesis. Such stark disagreements actually show the glaring need for a higher spatial resolution for solar-observing instruments. At least this was the general consensus that emerged from the Space Weather sessions I attended.
[2] I am using the term "gas" here, but actually the Sun's material is plasma. A gas - like oxygen at room temperature, has all its electrons. A plasma, on the contrary, is missing one or more electrons because of the high temperature it is subjected to. We say it is "once ionized" (one electron lost) "twice ionized" and so on. The significance of electrons being lost is that the gas becomes electrically conducting. Thus, a hydrogen plasma in the Sun will conduct electrical currents.
[3] In fact, the Sun has no definite surface, because it is a gaseous body. The 'surface' usually referred to, is that from which visible light emanates: the photosphere ('light-sphere'). It is very dense relative to higher layers, and is where most of the turbulent motions occur that can twist magnetic tubes.
[4] Differential rotation applies to a rotating fluid or gas. It means that the rate of rotation depends on the position of a point on the surface. In the case of the Sun, the fastest rotation is at the lowest latitudes, near the equator.
[5] There are some who claim variability arises from external changes in the Earth's orbit, rather than from internal changes in the Sun. Most often, the "Milankovitch Effect" is mentioned - whereby the Earth supposedly makes significant orbital changes, leading to much higher or lower mean global temperatures - depending on whether it is much nearer or farther from the Sun. At the present time, the solar research community gives very little credence to the "Milankovitch Effect", since there is no compelling evidence that it is significant enough to affect climate.
[6] Of course, there would be a long delay between the 'turn off' and when it was noticed on Earth! The average time needed for photons in the Sun's core (where nuclear reactions occur) to filter to the solar surface and escape - is about 1 million years. Thus, if all nuclear reactions shut down today - then the Sun would only 'black out' in one million more years (on average).
[7] See the papers on Ulysses findings: Science: Vol.268, May 19, 1995.
Wednesday, February 6, 2008
Getting to know the Sun (I)
I became enthralled with astronomy at the age of 12, after sending in a cereal boxtop plus fifty cents for a toy telescope. After the telescope arrived, I recall eagerly using it for nightly excursions around the South Florida sky. It may have been a toy - but it had enough magnifying power to allow me to resolve star clusters, and see the larger craters on the Moon. Some years later, I graduated to a larger telescope I constructed myself, and then to an amateur-astronomer sized scope: a Tasco 2.4 inch refractor.
With each succeeding telescope I more or less looked at the exact same objects: the brighter planets (Jupiter, Mars, Saturn, and Venus), star clusters (like the Pleiades), and the Moon. The idea was always to see how the increased size of the telescope allowed me to see more detailed features. However, by the time I reached the Tasco I was beginning to get somewhat jaded. What I needed was to find some purpose in my astronomical pursuits - apart from simple star-gazing.
It was around that time that I discovered - in my telescope carrying case, a tiny, darkened piece of flint glass embedded in a thick metal frame. Curious, I took it out and examined it up close. Then I rummaged through the box to find a small pamphlet describing the use of "your solar filter". Evidently, the filter was screwed on to the front of the eyepiece assembly - just ahead of the eyepieces. Once in place, the Sun could be viewed safely and sunspots became visible. I was absolutely amazed that so many ominous looking dark spots could nearly fill up the surface and not make any difference in the brightness.
For the next several weeks I became completely captivated by my solar observations, specifically the transit of large sunspots across the Sun's disk. What particularly fuelled my interest was a book I had borrowed from the local library entitled Our Star The Sun, by Donald Menzel of Harvard Observatory[1]. In this fascinating book I learned that the Sun the "daytime star" - was the source of all life on the Earth, and actually "the only practical reason for the study of astronomy". Change the physical nature of the Sun by 1 percentage point, and the survival of the human race, and all life on planet earth, was threatened. In the words of Sir Fred Hoyle:[2]
...if the Sun were to vary a little, only a very little, we should soon be faced by a situation besides which the political crises that fill our lives would fall into entire insignificance
To many laymen, the Sun appears so hot and bright, that no conscious connection is made to the pinpoints of light seen at night. The Sun tends to be segregated from the other stars entirely. Why the extreme difference in appearance if the Sun is a star like the others? To illustrate, the nearest star to Earth other than the Sun is very similar in physical characteristics: size, brightness, mass and surface temperature. It is called Alpha Centauri, and is 4.3 light years away. This works out to 270,000 times further than the Sun's 93 million miles. It looks like a fairly bright pinpoint because of its distance. However, the Sun would look exactly like it if its distance could be magically increased 270,000-fold.
A physical principle used in astronomy states that the brightness of a light source - like a star, decreases as the square of its distance. In concrete terms, if I look at a 100 watt bulb and a 40 watt bulb from ten feet away, I will judge the 100 watt bulb to be significantly brighter (two-and-a-half times to be exact). However, if I were to move the 100 watt bulb to a distance of 100 feet - keeping the 40 watt bulb at ten feet, what will I see? The 100 watt bulb is now ten times further than it was for the original comparison, so its apparent brightness is now (1/102) = 1/100 of what it was, or equivalent to a 1 watt bulb. Thus, the 40 watt bulb will now appear 40 times brighter even though intrinsically it isn't.
The same principle applies to the more distant stars. There are stars thousands of times brighter than the Sun, but they appear as dim pinpoints because they are so much farther away. One would have to "move" them to the same distance as the Sun (93 million miles) to get an appreciation for their actual properties in relation to the Sun's.[3] (Though, if that feat could be achieved, all life on Earth would be incinerated in a microsecond!) What is the point of all this? Simply this: without an awareness of the inverse-square law for light, humans would be deluded into the false perception that their particular star (the Sun) was the biggest and brightest in the universe. This is assuming they included the Sun in the same category as the distant stars. It is certainly not intuitive.
Application of the physical principle removes the Sun's specialness - placing it in the category of a very ordinary, garden variety star known as a "yellow dwarf". There are a multitude of stars that are thousands of times hotter and brighter, and hundreds of times bigger in size. Be that as it may, these same physically imposing attributes place those stars in an improbable position to support life-bearing planets. This will apply to the Sun in another 4 billion or so years: it will be approximately three hundred times its present diameter as a "red giant". All the inner planets, including Earth, will be reduced to burnt out cinders as the Sun expands to devour them one by one. If giant, Earth-smashing asteroids don't succeed in impressing upon humans the need to spread themselves around the cosmos, this certainly should.
A catastrophe like the one above can be well-predicted from nuclear physics. Astronomers know the Sun will one day consume its hydrogen, forcing it to burn less-efficient helium (into which the original hydrogen would have been converted).[4] When the helium is used up, an even less efficient fuel in the form of carbon remains. To compensate for the considerable loss in fuel efficiency (lower temperatures) the solar core must contract under the force of gravity. This generates a good deal of heat, causing the surrounding layers of the Sun's atmosphere to inflate. (Since a heated gas expands). The only major uncertainty is whether this inflation will amount to 100 times the present size, or 500. In terms of human life surviving, it won't make any difference: planet Earth will be just as well roasted.
Of course, solar changes need not be as dramatic as these for life's grip to become very tentative. A change in solar energy output by as little as two percent could threaten most species on Earth with extinction - since the planet would either be transformed into a vast, arid wasteland with daytime temperatures approaching 125 degrees or, alternatively, a frigid glacier with daytime temperatures averaging 50 below zero. Possibly, some hardy bacteria and viruses might survive - but not much else. It is difficult to see how humans could sustain themselves in a hostile environment nearly devoid of water.
In the early and mid-1980's, measurements made by an instrument called ACRIM (Active Cavity Radiometer Irradiance Monitor), aboard the SolarMax satellite, detected an increase of one-half percent in the Sun's brightness on several occasions - due to the presence of many large sunspots. The instrument was capable of detecting changes in energy as small as one-thousandth of one percent. These small order differences would amount to an increase in the Sun's surface temperature on the order of 100 degrees Fahrenheit.
Given that an increase in energy output correlates with the appearance of many spots, it is reasonable to suppose the opposite is true as well: a dearth of sunspots correlates with cooler temperatures. While the ACRIM did find a few such cases, the most notable study is that of John Eddy on the so-called "Maunder Minimum" - over the 17th - 18th centuries, when relatively few sunspots were visible from historical records.[5] Coincidentally, much lower than average temperatures were the norm, earning the period the nickname "little ice age".
In Menzel's book I discovered that the sunspots I observed could "grow" to be as large as 100 thousand miles in diameter - more than twelve times the diameter of the Earth! The Sun's surface was also the site of titanic explosions called solar flares which could engulf as many as one thousand Earths, and release an energy equivalent to two-thousand million megaton H-bombs exploded simultaneously! (The Sun itself has a diameter equal to nearly 4 Earth-Moon distances, and if it could be placed on an immense balance - 330,000 Earths would be needed to equalize the scales.)
For the remainder of my high school senior year, until I left for college, I used my Tasco with the solar filter to observe the passage of sunspots. Following Menzel's guidelines I was actually able to track the same group of spots across the solar surface and deduce the Sun's rotation period, of about 27 days. Thus began what was to be a lifelong fascination with the nearest star, and the basis for future research that has continued to this day. (Though the emphasis has changed from simple sunspot transits to their relationship to solar flares).
Is the Sun really as important as Menzel (and others) have portrayed it? Consider this: in 1973, the Skylab orbiting platform, with solar observing equipment aboard, detected a solar flare that wiped out twenty percent of the (then) ozone layer over North America. In March, 1989, a mammoth solar flare erupted in a region of very large spots, knocking out Ottawa's power grid. Nearly a half-million people were deprived of electricity, for nearly ten hours.[6] A massive magnetized cloud, from a solar eruption on January 6, 1997, is believed to have knocked out a Telstar 401 communications satellite on January 11.
Granted, "monster" flares such as these are somewhat rare, but they disclose how precariously human existence is in relation to the Sun's behavior. Fortunately for humans, the Sun is so steady in behavior that we scarcely notice it - unless we go out and get sunburned. If, by contrast, the Sun were a variable star that changed only a few percent each year in temperature and brightness, we would all be in jeopardy. A minor increase in temperature and brightness of a few percent would blind most inhabitants of Earth, and make the temperatures extremely uncomfortable - reaching the hundred-plus degree mark even at the poles, in winter.
As it is, the issue of whether the Sun is variable or not has still not been settled. There is some circumstantial evidence, including variable tree-ring growth, that the Sun is a "long-term" variable star, and more recent evidence it is short term as well.[7] The former case implies changing its temperature and brightness a few percent every 10,000 years or so. There has been some speculation that just such a change occurred around 10,000 years ago and brought the last ice age to a close. More recently, in the 1800's, an extended period of cold weather gripped much of the planet prompting the term "little ice age" to be used. Interestingly, this corresponded to a period of below-average sunspot frequency now referred to as "the Maunder Minimum", after the astronomer who made the original association.
The possible variability of the Sun, as well its potential for violent eruptions (in solar flares) makes it a pre-eminent subject of astronomical, and human importance. Indeed, attention to the Sun's behavior extends beyond the domain of esoteric research. Defense agencies and the military, for example, as well as power companies and telecommunications systems, are regular consumers of solar data - specifically flares, but also the particle bursts that result from flares. The data is provided through the 24 hours monitoring of the Space Environment Services Center of the National Oceanic and Atmospheric Administration. This is critical because, if conditions are right, energetic particles can saturate the delicate electronic detectors on board a spy or communications satellite. (As occurred with the Telstar 401 in January, 1997).
None of this is mysterious, of course. For years short wave fadeouts known as Dellingers originated with the passage of large sunspot groups with their powerful magnetic fields, near the center of the Sun. Solar flares magnify the effects, especially with electronic detectors on aircraft and in satellites. In some cases, large flares (with high x-ray output) have been known to cause malfunctions in navigation systems aboard commercial aircraft.
All of these provide compelling reasons to study the Sun - so I 've never had any problems explaining why I am "into" solar research - specifically the prediction of flares from sunspots.
Actually, prediction is probably a fairly strong word. The term that is generally favored is "forecasting", and that is just about what many solar observers and researchers do: use their data to make as reliable a forecast (say on flare occurrence) as we can. More often than not, we do not fare any better than weather forecasters.
[1] Menzel, D.: 1958, Our Star the Sun, Harvard University Press, Cambridge, Mass.
[2] Hoyle, F: The Frontiers of Astronomy, Signet Science Books, New York, p. 19.
[3] In fact, there is an easier way. Astronomers use the level playing field called 'absolute magnitude' to compare stars at the same distance. In this scheme, the inverse square law is used to adjust the distance/brightness of all stars to a standard distance of 10 parsecs or 32.2 light years (1 parsec = 3.26 light years). The magnitude scale is really a logarithmic brightness scale, with every even 5 magnitudes corresponding to 100 times brightness difference, and every one magnitude difference corresponding to 2.512 times brightness difference (2.512 being the fifth root of 100).
In this scheme, the Sun's 'absolute magnitude' is rated at +4.8, and that of the dog star Sirius at (-1.6). Since the more positive scale refers to a dimmer star, this implies that Sirius is really some 363 times brighter than the Sun (e.g. 2.512 raised to the power (4.8 - (-1.6)) = 6.4. Note that 'absolute magnitude' is only meaningful for light sources, e.g. stars - not planets - which are only visible by virtue of reflecting sunlight.
[4] The nuclear burning within stars is nicely discussed in numerous texts I will cite at the conclusion of the series.
[5] See, e.g. Eddy, J.A. 1976, in Science, Vol. 192, p. 1189.
[6] This was discussed in a presentation by solar physicist Hal Zirin at the joint American Geophysical Union - Solar Physics Division of the American Astronomical Society Conference held in Baltimore on Thursday, May 26, 1994. (The Conference, marking the 75th Anniversary of the AGU, lasted from the 24th through the 27th of May). Zirin included a slide showing a transformer power cable - such as used in the Ottawa system -with its copper wires melted. (Each copper wire had the thickness of a man's thumb). What happened is that electrically charged particles from the huge flare caused large currents (> 10^6 A) to be induced inside the power lines and transformer wires. The resulting electrical load was simply too much for the circuit conductors to accommodate - something like a fuse blowing in a household circuit.
[7] See: 'A Fickle Sun Could Be Altering Earth's Climate After All', in Science, Vol. 269, (Aug. 4, 1995), p. 633.
With each succeeding telescope I more or less looked at the exact same objects: the brighter planets (Jupiter, Mars, Saturn, and Venus), star clusters (like the Pleiades), and the Moon. The idea was always to see how the increased size of the telescope allowed me to see more detailed features. However, by the time I reached the Tasco I was beginning to get somewhat jaded. What I needed was to find some purpose in my astronomical pursuits - apart from simple star-gazing.
It was around that time that I discovered - in my telescope carrying case, a tiny, darkened piece of flint glass embedded in a thick metal frame. Curious, I took it out and examined it up close. Then I rummaged through the box to find a small pamphlet describing the use of "your solar filter". Evidently, the filter was screwed on to the front of the eyepiece assembly - just ahead of the eyepieces. Once in place, the Sun could be viewed safely and sunspots became visible. I was absolutely amazed that so many ominous looking dark spots could nearly fill up the surface and not make any difference in the brightness.
For the next several weeks I became completely captivated by my solar observations, specifically the transit of large sunspots across the Sun's disk. What particularly fuelled my interest was a book I had borrowed from the local library entitled Our Star The Sun, by Donald Menzel of Harvard Observatory[1]. In this fascinating book I learned that the Sun the "daytime star" - was the source of all life on the Earth, and actually "the only practical reason for the study of astronomy". Change the physical nature of the Sun by 1 percentage point, and the survival of the human race, and all life on planet earth, was threatened. In the words of Sir Fred Hoyle:[2]
...if the Sun were to vary a little, only a very little, we should soon be faced by a situation besides which the political crises that fill our lives would fall into entire insignificance
To many laymen, the Sun appears so hot and bright, that no conscious connection is made to the pinpoints of light seen at night. The Sun tends to be segregated from the other stars entirely. Why the extreme difference in appearance if the Sun is a star like the others? To illustrate, the nearest star to Earth other than the Sun is very similar in physical characteristics: size, brightness, mass and surface temperature. It is called Alpha Centauri, and is 4.3 light years away. This works out to 270,000 times further than the Sun's 93 million miles. It looks like a fairly bright pinpoint because of its distance. However, the Sun would look exactly like it if its distance could be magically increased 270,000-fold.
A physical principle used in astronomy states that the brightness of a light source - like a star, decreases as the square of its distance. In concrete terms, if I look at a 100 watt bulb and a 40 watt bulb from ten feet away, I will judge the 100 watt bulb to be significantly brighter (two-and-a-half times to be exact). However, if I were to move the 100 watt bulb to a distance of 100 feet - keeping the 40 watt bulb at ten feet, what will I see? The 100 watt bulb is now ten times further than it was for the original comparison, so its apparent brightness is now (1/102) = 1/100 of what it was, or equivalent to a 1 watt bulb. Thus, the 40 watt bulb will now appear 40 times brighter even though intrinsically it isn't.
The same principle applies to the more distant stars. There are stars thousands of times brighter than the Sun, but they appear as dim pinpoints because they are so much farther away. One would have to "move" them to the same distance as the Sun (93 million miles) to get an appreciation for their actual properties in relation to the Sun's.[3] (Though, if that feat could be achieved, all life on Earth would be incinerated in a microsecond!) What is the point of all this? Simply this: without an awareness of the inverse-square law for light, humans would be deluded into the false perception that their particular star (the Sun) was the biggest and brightest in the universe. This is assuming they included the Sun in the same category as the distant stars. It is certainly not intuitive.
Application of the physical principle removes the Sun's specialness - placing it in the category of a very ordinary, garden variety star known as a "yellow dwarf". There are a multitude of stars that are thousands of times hotter and brighter, and hundreds of times bigger in size. Be that as it may, these same physically imposing attributes place those stars in an improbable position to support life-bearing planets. This will apply to the Sun in another 4 billion or so years: it will be approximately three hundred times its present diameter as a "red giant". All the inner planets, including Earth, will be reduced to burnt out cinders as the Sun expands to devour them one by one. If giant, Earth-smashing asteroids don't succeed in impressing upon humans the need to spread themselves around the cosmos, this certainly should.
A catastrophe like the one above can be well-predicted from nuclear physics. Astronomers know the Sun will one day consume its hydrogen, forcing it to burn less-efficient helium (into which the original hydrogen would have been converted).[4] When the helium is used up, an even less efficient fuel in the form of carbon remains. To compensate for the considerable loss in fuel efficiency (lower temperatures) the solar core must contract under the force of gravity. This generates a good deal of heat, causing the surrounding layers of the Sun's atmosphere to inflate. (Since a heated gas expands). The only major uncertainty is whether this inflation will amount to 100 times the present size, or 500. In terms of human life surviving, it won't make any difference: planet Earth will be just as well roasted.
Of course, solar changes need not be as dramatic as these for life's grip to become very tentative. A change in solar energy output by as little as two percent could threaten most species on Earth with extinction - since the planet would either be transformed into a vast, arid wasteland with daytime temperatures approaching 125 degrees or, alternatively, a frigid glacier with daytime temperatures averaging 50 below zero. Possibly, some hardy bacteria and viruses might survive - but not much else. It is difficult to see how humans could sustain themselves in a hostile environment nearly devoid of water.
In the early and mid-1980's, measurements made by an instrument called ACRIM (Active Cavity Radiometer Irradiance Monitor), aboard the SolarMax satellite, detected an increase of one-half percent in the Sun's brightness on several occasions - due to the presence of many large sunspots. The instrument was capable of detecting changes in energy as small as one-thousandth of one percent. These small order differences would amount to an increase in the Sun's surface temperature on the order of 100 degrees Fahrenheit.
Given that an increase in energy output correlates with the appearance of many spots, it is reasonable to suppose the opposite is true as well: a dearth of sunspots correlates with cooler temperatures. While the ACRIM did find a few such cases, the most notable study is that of John Eddy on the so-called "Maunder Minimum" - over the 17th - 18th centuries, when relatively few sunspots were visible from historical records.[5] Coincidentally, much lower than average temperatures were the norm, earning the period the nickname "little ice age".
In Menzel's book I discovered that the sunspots I observed could "grow" to be as large as 100 thousand miles in diameter - more than twelve times the diameter of the Earth! The Sun's surface was also the site of titanic explosions called solar flares which could engulf as many as one thousand Earths, and release an energy equivalent to two-thousand million megaton H-bombs exploded simultaneously! (The Sun itself has a diameter equal to nearly 4 Earth-Moon distances, and if it could be placed on an immense balance - 330,000 Earths would be needed to equalize the scales.)
For the remainder of my high school senior year, until I left for college, I used my Tasco with the solar filter to observe the passage of sunspots. Following Menzel's guidelines I was actually able to track the same group of spots across the solar surface and deduce the Sun's rotation period, of about 27 days. Thus began what was to be a lifelong fascination with the nearest star, and the basis for future research that has continued to this day. (Though the emphasis has changed from simple sunspot transits to their relationship to solar flares).
Is the Sun really as important as Menzel (and others) have portrayed it? Consider this: in 1973, the Skylab orbiting platform, with solar observing equipment aboard, detected a solar flare that wiped out twenty percent of the (then) ozone layer over North America. In March, 1989, a mammoth solar flare erupted in a region of very large spots, knocking out Ottawa's power grid. Nearly a half-million people were deprived of electricity, for nearly ten hours.[6] A massive magnetized cloud, from a solar eruption on January 6, 1997, is believed to have knocked out a Telstar 401 communications satellite on January 11.
Granted, "monster" flares such as these are somewhat rare, but they disclose how precariously human existence is in relation to the Sun's behavior. Fortunately for humans, the Sun is so steady in behavior that we scarcely notice it - unless we go out and get sunburned. If, by contrast, the Sun were a variable star that changed only a few percent each year in temperature and brightness, we would all be in jeopardy. A minor increase in temperature and brightness of a few percent would blind most inhabitants of Earth, and make the temperatures extremely uncomfortable - reaching the hundred-plus degree mark even at the poles, in winter.
As it is, the issue of whether the Sun is variable or not has still not been settled. There is some circumstantial evidence, including variable tree-ring growth, that the Sun is a "long-term" variable star, and more recent evidence it is short term as well.[7] The former case implies changing its temperature and brightness a few percent every 10,000 years or so. There has been some speculation that just such a change occurred around 10,000 years ago and brought the last ice age to a close. More recently, in the 1800's, an extended period of cold weather gripped much of the planet prompting the term "little ice age" to be used. Interestingly, this corresponded to a period of below-average sunspot frequency now referred to as "the Maunder Minimum", after the astronomer who made the original association.
The possible variability of the Sun, as well its potential for violent eruptions (in solar flares) makes it a pre-eminent subject of astronomical, and human importance. Indeed, attention to the Sun's behavior extends beyond the domain of esoteric research. Defense agencies and the military, for example, as well as power companies and telecommunications systems, are regular consumers of solar data - specifically flares, but also the particle bursts that result from flares. The data is provided through the 24 hours monitoring of the Space Environment Services Center of the National Oceanic and Atmospheric Administration. This is critical because, if conditions are right, energetic particles can saturate the delicate electronic detectors on board a spy or communications satellite. (As occurred with the Telstar 401 in January, 1997).
None of this is mysterious, of course. For years short wave fadeouts known as Dellingers originated with the passage of large sunspot groups with their powerful magnetic fields, near the center of the Sun. Solar flares magnify the effects, especially with electronic detectors on aircraft and in satellites. In some cases, large flares (with high x-ray output) have been known to cause malfunctions in navigation systems aboard commercial aircraft.
All of these provide compelling reasons to study the Sun - so I 've never had any problems explaining why I am "into" solar research - specifically the prediction of flares from sunspots.
Actually, prediction is probably a fairly strong word. The term that is generally favored is "forecasting", and that is just about what many solar observers and researchers do: use their data to make as reliable a forecast (say on flare occurrence) as we can. More often than not, we do not fare any better than weather forecasters.
[1] Menzel, D.: 1958, Our Star the Sun, Harvard University Press, Cambridge, Mass.
[2] Hoyle, F: The Frontiers of Astronomy, Signet Science Books, New York, p. 19.
[3] In fact, there is an easier way. Astronomers use the level playing field called 'absolute magnitude' to compare stars at the same distance. In this scheme, the inverse square law is used to adjust the distance/brightness of all stars to a standard distance of 10 parsecs or 32.2 light years (1 parsec = 3.26 light years). The magnitude scale is really a logarithmic brightness scale, with every even 5 magnitudes corresponding to 100 times brightness difference, and every one magnitude difference corresponding to 2.512 times brightness difference (2.512 being the fifth root of 100).
In this scheme, the Sun's 'absolute magnitude' is rated at +4.8, and that of the dog star Sirius at (-1.6). Since the more positive scale refers to a dimmer star, this implies that Sirius is really some 363 times brighter than the Sun (e.g. 2.512 raised to the power (4.8 - (-1.6)) = 6.4. Note that 'absolute magnitude' is only meaningful for light sources, e.g. stars - not planets - which are only visible by virtue of reflecting sunlight.
[4] The nuclear burning within stars is nicely discussed in numerous texts I will cite at the conclusion of the series.
[5] See, e.g. Eddy, J.A. 1976, in Science, Vol. 192, p. 1189.
[6] This was discussed in a presentation by solar physicist Hal Zirin at the joint American Geophysical Union - Solar Physics Division of the American Astronomical Society Conference held in Baltimore on Thursday, May 26, 1994. (The Conference, marking the 75th Anniversary of the AGU, lasted from the 24th through the 27th of May). Zirin included a slide showing a transformer power cable - such as used in the Ottawa system -with its copper wires melted. (Each copper wire had the thickness of a man's thumb). What happened is that electrically charged particles from the huge flare caused large currents (> 10^6 A) to be induced inside the power lines and transformer wires. The resulting electrical load was simply too much for the circuit conductors to accommodate - something like a fuse blowing in a household circuit.
[7] See: 'A Fickle Sun Could Be Altering Earth's Climate After All', in Science, Vol. 269, (Aug. 4, 1995), p. 633.