I Do Not Fear Missing the Solar Eclipse

The great solar eclipse of North America has gotten a lot of publicity recently, and rightly so.  It is a script written for movies, a stark event to be witnessed by large areas of a large country.  Everyone from the professional astrophysicist to the completely uninitiated layman will appreciate it.

There is just one small hitch though – the weather.  Cloud cover may potentially block some or all of the eclipse.  This is not unusual for an astronomical affair, with the main casualty here being the lost opportunity due to the infrequency of this particular one’s chance.  The last solar eclipse in North America was over ninety years ago.  The next will be in seven.  After that, likely none of us today will be alive for the solar eclipse of 2099.

Last year, in May 2016, was the latest transit of the planet Mercury across the Sun.  This too is a rare event, though with a frequency of about once every 13 years.  While location on Earth is important, there is still a decent chance you can witness a Mercury transit over the course of 30-40 years.

I was in a prime location for the Mercury transit and had a full seven hours to observe it.  Unfortunately, the clouds that day were like a mockery from the gods, with the densest cover short of a severe thunderstorm.  My days of preparation and planning with telescope and solar filter and camera were fruitless.

Now being days away from the August 21st eclipse, I watch the weather forecasts for Monday like a hawk.  Currently they foretell party cloudy, muggy, with a chance of a thunderstorm, but with an uncomfortable encroachment of rain first in the evening and now late afternoon.  In my area, the eclipse will be at its peak around 13:20 and over by 14:45.

Will I be disappointed if the weather does not cooperate?  Absolutely.  Fortunately, there are a few mitigating perspectives.

First as a practical matter, cloud cover does not necessarily mean the eclipse will not be observable.  The Sun is very powerful and can pierce a variety of cloud formations.  I have taken pictures of star and planets through cloud cover when they were invisible to the eye alone, and have imaged the Sun through clouds as well.  Clouds can actually provide an artistic effect through a solar filter when imaging.

The second is a much longer perspective.  I hope those unfamiliar with astronomy take this as an opportunity to begin their own personal explorations of the cosmos.  A solar eclipse it just one event, but there is so much more to see, so much more to wonder at!  Every clear night offers something spectacular if you know how to observe the sky.

The Moon, the planets, meteors, nebulae, star clusters, galaxies, binary stars, constellations.  Conjunctions, oppositions, Jovian moon transits.  They are all there, if not all the time then at least for long durations annually, every night for the taking.

This will also be a useful opportunity to push the cause of light pollution.  Though the wonders of the cosmos are out there, too much of our planet is poisoned by the sickly orange sky glow that ranks with any other pollution source.  Few people know about it, as it is not easy to realize, but artificial lighting at night distorts ecosystems.  If you don’t believe me, try sleeping with your bedroom light on, every night.

So even if the weather forces me to miss the eclipse, I know it will not be the end-all, because of all the amazing things in the sky and all the other astronomical events, including eclipses, to come.  The clouds cannot win every time!

Starlight and Einstein and Solar Eclipses

Much talk is in the media these recent days about the upcoming North America solar eclipse.  Anyone following the world of astronomy for the past year at least has been aware of it, but suddenly the mass population is waking up to the pending reality of the event too.  Their focus is on traffic jams and hotel rooms and possibly defective solar glasses.

Having prepared for August 21st months ago, I am now waiting just like most of you, and watching the weather forecasts with an interest usually not provided to the television personalities.  I will not be using glasses, in part because I enjoy doing things differently than most.  So while millions will gaze up with open mouths at the Moon and Sun with their 3D-esque eyewear, I will be leveraging my telescopes along with simple cardboard holdouts to measure the event.

This waiting time is a good time to reflect on the eclipse and what it means beyond the covering of the Sun.  The eclipse will bring darkness and with darkness comes stars.  I am in the 88% coverage range and have no idea what it will look like, though I assume at least bright Venus towards the West will be visible.

Those in the path of totality will have a special treat as the sky should go dark to the point stars appear.  It was this phenomena that helped prove Albert Einstein’s General Theory of Relativity true, or at least as a superior theory to explain the universe over Isaac Newton’s gravitational theories.  If you want to read the details of how it was done, do an Internet search for the 1919 solar eclipse to find many articles.  Here is one from space.com that summarizes it nicely.

I am neither astrophysicist nor physicist, just a backyard astronomer.  But I feel I know enough to explain the 1919 solar eclipse experiment in the simplest terms.  Consider first a typical clear evening on the planet Earth, with stars shining and the Sun well out of the way on the other side of the globe.

Figure 1 (not to scale)

With no large cosmological objects in the way, starlight in aggregate gets to Earth mostly on a straight line.  Whether Einstein was correct or not was not crucial for this part.  There is a path of light from a star to here, and we can assume a straight line for this path.

Now consider what happens during a solar eclipse.  The Sun (and Moon) have gotten into the path of some of that starlight, but for other stars their light will skirt past the Sun and still reach Earth.  Einstein asked, “will the gravity of our massive Sun alter course of light from those stars?”  His theories said yes, and the 1919 eclipse was used to prove him and his theories correct.

Figure 2 (not to scale)

Figure 2 shows a few things happening.  First, the Moon is between the Sun and Earth, hence blocking the Sun’s light.  The Sun of course is enormous in size compared to the Earth and Moon, but the Moon’s proximity to us and the Sun’s distance make them approximately the same apparent size in the sky.  If one were to make an argument that the ancient gods set up the universe so that their sizes looked the same, you would probably have difficultly coming up with a sound rebuttal for why this is so, beyond coincidence.

Next, the Sun blocks some, a very small amount, of starlight that is directly behind it.  I suppose you could say that the Earth, Moon, Sun, and any stars hidden behind the Sun will be in conjunction on August 21st.

Lastly, there is starlight with paths that will approach the Sun.  As proven in 1919, the Sun’s gravity will effects this starlight as it travels past the Sun, altering the starlight’s course.  This is happening all the time in the daylight, but we cannot observe it due to that -27 magnitude star close by.

When the masses of millions look at Monday’s eclipse, few will be thinking about Einstein.  But some yearning, bright individuals will.  Perhaps the next Einstein will be among them, awaiting the inspiration to change our fundamental understanding of the cosmos once again.

Why I Stopped Watching “Doctor Who”

Here is another tangent from my normal postings, but if you bear with me for a few paragraphs more, I promise to tie it back to astronomy.

I was, or I guess still am, a lifelong Doctor Who fan, though I stopped watching the series over a year ago.  Apparently, a new Doctor actor was recently selected, which brings the series back to mind.

That this character could change physical shape and still be the same person was a brilliant way to keep the series alive for well past 50 years, minus about 15 years hiatus.  We always felt a connection to the Doctor, the same person, no matter who the actor.

When I was young, I wondered what his last regeneration would be like, specifically his thirteenth (since Time Lords could regenerate twelve times).  What would the Doctor be like, facing his own mortality?  I thought they would be fascinating tales, to explore how such a long-lived character would react to and reconcile the approach of his final, impending death.  Those potential stories, well into the future, captured my imagination.

The future and its potential never arrived, though, and probably never will.  My Doctor Who bubble burst upon the absurd twist that the Doctor was now on his final regeneration early, “War Doctor” notwithstanding, and that the Time Lords, now deities, could bestow the gift of eternal life.  The show kind of ended for me then as I realized there would be no final contemplation on the Doctor’s life and death beyond the terribly superficial rampant in “sci-fi” and fantasy today.

I and all longtime fans were robbed of this chance to learn the Doctor’s closing narrative.  There will never be a final chapter now that the canonical nature of regenerations has been sent to oblivion.  Once the Doctor would have passed, a successor could have certainly stepped in, be it a descendant, partner, or some other Time Lordy-type entity.  The entertainment industry does not like death, beyond the ability to jump-start characters back to life.  You cannot sell commercials or movie tickets when the best characters are forever dead in their fictitious realities.  And so characters keep coming back on screen, compliments of genesis worlds, alternative timelines, and pagan mercy.

It is unfortunate that death is rarely explored sufficiently in genres related to science fiction, especially for the most beloved characters.  The quest to understand, particularly the heavens, is intrinsically linked to the cosmos’s truth that all things expire in this universe.  Stars form and fade, spectacularly at times. Planets are born and live, but will either burn up or crash into bigger objects, eventually.  The energy of the universe will expire someday, when all stars have burned out and there are no light elements left, no hydrogen nor helium, sufficient to form new ones.

These are wonderful philosophical matters to ponder.  It is just unfortunate that our society goes to such lengths to impede this exploration, be it light pollution blocking our night skies or through pulp stories watched on television.

A Very Brief History of Astronomy

As told by Neil deGrasse Tyson in his co-authored book, Welcome to the Universe: An Astrophysical Tour:

“For thousands of years, all we could do was measure the brightness of a star, its position in the sky, and maybe note its color.  This was classical astronomy.  It became modern astrophysics when we started obtaining spectra, because spectra allowed us to understand chemical composition, and our accurate interpretation of spectra came from quantum mechanics.

“We had no understanding of spectra until quantum mechanics was developed.  Planck introduced his constant in 1900, and in 1913 Bohr made his model of the hydrogen atom, with electrons in orbitals based on quantum mechanics, which explained the Balmer series.

“Modern astrophysics really didn’t get under way until after that, in the 1920s.  Think about how recent this is.  The oldest people alive today were born when astrophysics was starting.  For thousands of years, we were essentially clueless about stars, yet in one human lifetime we have come to know them well.

“In 1926, Edwin Hubble discovered that the universe is bigger than anybody had thought, because he revealed that galaxies live far beyond the stars of our own Milky Way.  And in 1929, he discovered that the universe is expanding.  These leaps of understanding happened in the lifetime of people alive today.  Extraordinary.

“I often ask myself, what revolutions await us in the next several decades?  What cosmic discoveries will you witness that you can tell your descendants about?”

– Neil deGrasse Tyson