How Sunspots Led to House Arrest for Galileo, and Frequently Asked Sunspot Questions Answered

Galileo was born on February 15, 1564, with a fate destined to be as star-crossed as the lover’s holiday, Valentine’s Day, directly preceding his birth. Or, perhaps, sun-crossed might be the better term for the Italian astronomer widely credited with discovering dark, planet-sized regions of chaotic magnetic activity on the sun called sunspots.

When viewed through the lens of a telescope (an instrument invented just three years prior to Galileo’s discovery), sunspots appeared to Galileo as “spots” or “blemishes” on the sun’s surface that we now know occur in cycles of dearth then abundance roughly every 11 years. But “blemish” is a bit of a misnomer. As ham’s know, sunspots are no sinister phenom. With the increased solar activity, as evidenced by Solar Cycle 25, hams enjoy more frequent openings on 20 through 10 meters and 6 meters, plus better skip propagation, and an improved chance of nabbing hard-to-reach QSOs.

And it’s all thanks to Galileo who made the discovery in 1611, turning Christian doctrine on its head by suggesting (rightly so) that sunspots were components of a universe constantly in motion, flux, and change…not already perfect but in process. It countered the status-quo consensus that Earth was unmoving and stood still in infinite perfection as planets, as well as the sun, revolved around it.

To which, Galileo is famously remembered for saying, “And yet, it moves.” However, the church was not open to debate, arguing that Earth was pristine and unmoving, an absolute fact of scripture, that could not be argued despite the centuries of scientific findings suggesting otherwise, including Galileo’s.

In fact, the church felt so strongly on the matter that they would forbid Galileo from holding or defending his beliefs in 1616. They later held him on trial for heresy in 1633. Not to be easily stopped, Galileo continued on his scientific quest writing about his observations in his Letters on Sunspots and other works, countering efforts of the church to stop him by arguing his posits were merely “discussions,” not condemnable “beliefs.”

However, on June 22, 1633, he was tried and convicted of heresy by the church:

“We pronounce, judge, and declare, that you, the said Galileo…have rendered yourself vehemently suspected by this Holy Office of heresy, that is, of having believed and held the doctrine (which false and contrary to the Holy and Divine Scriptures) that the Sun is the center of the world and that it does not move from east to west and that the Earth does move and is not the center of the world.”

He was ultimately condemned for his queries: “We order that by a public edict the book of Dialogues of Galileo Galilei be prohibited, and we condemn thee to the prison of this Holy Office during our will and pleasure; and as a salutary penance, we enjoin on thee that for the space of three years, thou shalt recite once a week the Seven Penitential Psalms.”

Galileo would spend the rest of his life under house arrest. He died on January 8, 1642, at the age of 77 following an episode of heart palpitations and fever. Three hundred years would pass before the church would publicly admit the validity of Galileo’s claims and clear his name of heresy.

Which leads us to the less controversial times of today when our solar system is better understood in both scientific and religious communities. And to offer even greater clarity, we’ve included some frequently asked solar cycle questions for newbies below:

How often does the solar cycle occur?

Roughly every 11 years the number of sunspots increases from nearly zero to more than 100 and then back to nearly zero as the new cycle begins.

How does the cycle work?

When one 11-year cycle transitions into a new cycle, it starts with low solar activity (solar minimum) then builds until the magnetic field reverses at the cycle’s peak or solar maximum.

When did Solar Cycle 25 begin?

December of 2019 with a minimum smoothed sunspot number of 1.8. The cycle is expected to continue until 2030.

When will the solar maximum occur?

It is predicted to take place between November of 2024 and March of 2026.

How long have scientists been recording sunspots?

Sunspots were first recorded in 1755 and have been recorded every single day since.

Can sunspots cause issues in outer space or on Earth?

Increased activity on the sun can cause solar flares or eruptions. These put more charged particles into space. The particles can cause radio signal interruption, surges in electrical grids, damage to GPS satellites, and risks to spacecrafts and astronauts on the International Space Station.

How does the solar minimum affect DXing?

During a solar minimum the ionosphere isn’t as charged as it is during a maximum, and low-frequency radio waves aren’t reflected very well. Contact distance is reduced, and radio waves can’t reach out as far, resulting in fewer contacts made and, sometimes, a frustrating day on the bands. Likewise, a solar maximum means mad DXing opportunities, and lots of (usually) tricky contacts to be had!

How can hams avoid frustration during a solar minimum?

Hams can avoid the headaches of low solar activity by switching over to UHF/VHF operation to contact amateur radio satellites with HT or mobile rigs like the Icom IC-9700 VHF/UHF/1.2 GHz Transceiver, which features smooth satellite operation with normal/reverse tracking and 99 satellite channels.

Where can I find more information and daily space weather forecasts?

Dr. Tamitha Skov, Space Weather Woman has a great site about space weather and how it can affect us here on Earth. She’s a friend of DX Engineering who spent time with our crew at the 2019 Dayton Hamvention.

Take advantage of working more bands during Solar Cycle 25 with ARRL Station Log Books, Mini Log Books, and the book Radio Propagation Explained, a very good read, from DX Engineering!

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