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Seeing (Or Not Seeing) Spots

Above is the image of the Sun’s disk posted today on The sunspot number is 26. Here’s an experiment you can do yourself: Save the image off the page to disk, bring it up in an image browser, and zoom out until it’s about the size of (…a silver dollar? Nobody knows what those are anymore…) a spray can lid, or something else measuring two inches or under.

Now, how many sunspots can you see?

Imagine yourself an astronomer in 1700, using a telescope made with skills and understanding of optics available at the time, to project the Sun onto a card or a wall. How many sunspots would you see?

Be honest: Zip. Zero. None.

This is the problem we have comparing solar activity today with solar activity 200 or 250 years ago: People then did not have the instruments we have today, so the counts really don’t compare. Some efforts have been made to address this, but it’s really an unsolvable problem if we want accurate comparisons of sunspots in 1700 to sunspots today.

My point, which is hardly original with me, is that we see and count spots today that could not have been seen in 1700. So we may already be sliding into a Maunder-class solar minimum. If solar cycle 25 (roughly 2019-2030) is as weak as they’re predicting, it may exhibit few if any sunspots that astronomers in 1700 would have seen.

Nobody knows what this means. The Sun has been slowly going to sleep since its Grand Maximum in 1958 during cycle 19. I’m not going to claim that solar activity is the sole governor of climate, but it’s a major contributor. (And yes, you hotheads, I freely admit that CO2 does contribute to global warming. We’re still arguing about how much. Remember that you may not use the word “denier” in my comments.) My point is that most of us will live long enough to see whether sunspot counts are in any way a proxy for global temperature.

My blood oxygen issue is the major reason we’re moving to Phoenix. It’s by no means the only one.


  1. RH in CT says:

    Did you know that Denier (abbreviated D) is “a unit of measure for the linear mass density of fibers, is defined as the mass in grams per 9000 meters”?

    That “A fiber is generally considered a microfiber if it is one denier or less”?


    1. Heh. I knew of the unit of measure, but in my head I would have spelled it “deniere”. Nylon stockings used to be rated in deniers, unless I misrecall. (I’ll ask Carol if they still are.)

  2. Terry Ward says:

    This reminds of the changes in technology that have alerted the posting of warning signs on food products. Many health statutes refer to a “detectable” amount. When written, the detectable amounts were in the parts per thousand range. New technology now measures parts per many billions but the law still mandates that “detectable” equals dangerous.

  3. Rich Rostrom says:

    The relevant health statute was the 1958 “Delaney clause” added to
    the Food, Drugs, and Cosmetic Act of 1938.

    “the Secretary of the Food and Drug Administration shall not approve for use in food any chemical additive found to induce cancer in man, or, after tests, found to induce cancer in animals.” It made no distinction regarding artificial and natural compounds, relative potency, relative potency in different species, or actual concentration the final product. By the 1970s, it was obvious that that it was unenforceable – almost everything is carcinogenic in some species or other at high enough concentrations, and detectable with newer technology at insignificant levels.

    So the FDA adopted a de minimis rule; in the 1990s the FD&C Act was revised to allow this and other common-sense methods.

  4. Brad says:

    It is refreshing to hear someone who is not caught up in the mania of global warming apocalypse scenarios. I read that we are dangerously close to having most plant life die off because CO2 levels are, if anything, too low. At 150 ppm most plant life, and thus most other life, would die off. Great reading: I too suspect the sun has a lot more to do with the heating and cooling of our planet than many are giving it credit, and going back in to an ice age to me is a much scarier prospect than things heating up a little. When our ancestors first started to flourish there were palm trees in Alaska, more warmth and CO2 would mean more food for a growing population.

    Anyways, love your books, working through assembly step by step right now, and seriously eyeing your fiction works. Keep up the good work!

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