Jon Voisey - Astronomy Before the Telescope's Avatar

Jon Voisey - Astronomy Before the Telescope

@jonvoisey

68
Followers
40
Following
44
Posts
25.11.2024
Joined
Posts Following

Latest posts by Jon Voisey - Astronomy Before the Telescope @jonvoisey

Did an 11th Century Monk Realize Halley's Comet was Periodic?
Did an 11th Century Monk Realize Halley's Comet was Periodic? YouTube video by Astronomy Before the Telescope

Debunking a viral article.

06.02.2026 19:29 👍 0 🔁 0 💬 0 📌 0
The Most Historically Significant Book in Astronomy: Understanding Ptolemy's Almagest (Book V)
The Most Historically Significant Book in Astronomy: Understanding Ptolemy's Almagest (Book V) YouTube video by Astronomy Before the Telescope
29.01.2026 15:39 👍 0 🔁 0 💬 0 📌 0
Constellation Mythologies - Hercules
Constellation Mythologies - Hercules YouTube video by Astronomy Before the Telescope
30.12.2025 00:10 👍 0 🔁 0 💬 0 📌 0
Exploring Italy's Astronomical History
Exploring Italy's Astronomical History YouTube video by Astronomy Before the Telescope
03.12.2025 02:29 👍 1 🔁 0 💬 0 📌 0
Sicily's Golden Age of Astronomy
Sicily's Golden Age of Astronomy YouTube video by Astronomy Before the Telescope
20.11.2025 23:12 👍 0 🔁 0 💬 0 📌 0
Ignazio Danti and the Gregorian Calendar Reform
Ignazio Danti and the Gregorian Calendar Reform YouTube video by Astronomy Before the Telescope
16.11.2025 02:42 👍 0 🔁 0 💬 0 📌 0
Constellation Mythologies - Lyra
Constellation Mythologies - Lyra YouTube video by Astronomy Before the Telescope

www.youtube.com/watch?v=F39N...

09.08.2025 16:58 👍 0 🔁 0 💬 0 📌 0
Instrumentum Primi Mobilis - A Medieval Calculator
Instrumentum Primi Mobilis - A Medieval Calculator YouTube video by Astronomy Before the Telescope
08.08.2025 21:34 👍 0 🔁 0 💬 0 📌 0
Video thumbnail

Sorry for no new YouTube videos. I've been working on something that's going to take awhile....

03.07.2025 20:29 👍 0 🔁 0 💬 0 📌 0
Astronomical Alignments of the Kasta Tomb
Astronomical Alignments of the Kasta Tomb YouTube video by Astronomy Before the Telescope

I'm planning on heading to Greece this fall, but this site is not (yet) open to the public.

31.05.2025 19:37 👍 0 🔁 0 💬 0 📌 0
The Most Historically Significant Book in Astronomy: Understanding Ptolemy's Almagest (Book III)
The Most Historically Significant Book in Astronomy: Understanding Ptolemy's Almagest (Book III) YouTube video by Astronomy Before the Telescope
21.05.2025 00:47 👍 0 🔁 0 💬 0 📌 0
Constellation Mythologies - Cassiopeia
Constellation Mythologies - Cassiopeia YouTube video by Astronomy Before the Telescope
05.05.2025 22:26 👍 0 🔁 0 💬 0 📌 0
Constellation Mythologies - Cygnus
Constellation Mythologies - Cygnus YouTube video by Astronomy Before the Telescope

Trigger warning for Zeus being Zeus.

03.05.2025 23:38 👍 0 🔁 0 💬 0 📌 0
Book Review: Inside the Stargazer's Palace
Book Review: Inside the Stargazer's Palace YouTube video by Astronomy Before the Telescope
19.04.2025 18:17 👍 0 🔁 0 💬 0 📌 0
The Most Historically Significant Book in Astronomy: Understanding Ptolemy's Almagest (Books I & II)
The Most Historically Significant Book in Astronomy: Understanding Ptolemy's Almagest (Books I & II) YouTube video by Astronomy Before the Telescope
15.04.2025 00:10 👍 0 🔁 0 💬 0 📌 0
Three images of a diagram from the Almagest. The first is from BnF MS Grec 2389 (c600-800 CE). The second is from BnF MS Lat 16200 (1213 CE), and the last is a modern diagram from G.J. Toomer's translation in 1998. All of them depict an outer circle, an inner circle, and various diameters and chords drawn within them.

Three images of a diagram from the Almagest. The first is from BnF MS Grec 2389 (c600-800 CE). The second is from BnF MS Lat 16200 (1213 CE), and the last is a modern diagram from G.J. Toomer's translation in 1998. All of them depict an outer circle, an inner circle, and various diameters and chords drawn within them.

It's fun to look back at manuscripts and, even without being able to read them, recognizing the same figures over hundreds of years.

13.04.2025 15:59 👍 1 🔁 0 💬 0 📌 0

"When God made everything according to measure and number, He chose hard ones for astronomy."
~ J. L. Heilbron, "The Sun in the Church"

09.04.2025 12:48 👍 0 🔁 0 💬 0 📌 0

I bought a copy of that when I first came out. I can't remember if I read it or not...

31.03.2025 18:17 👍 0 🔁 0 💬 0 📌 0
The Real History Behind "Orb: On the Movements of the Earth"
The Real History Behind "Orb: On the Movements of the Earth" YouTube video by Astronomy Before the Telescope

Did you know that Netflix has an anime on SCA period astronomy?
Of course I reviewed it.

20.03.2025 00:18 👍 2 🔁 0 💬 0 📌 0
The Astrological Flood Panic of 1524
The Astrological Flood Panic of 1524 YouTube video by Astronomy Before the Telescope
26.02.2025 18:03 👍 1 🔁 0 💬 0 📌 0
Preview
Kitāb al-Diryāq. Kitāb al-Diryāq. -- 1198 -- manuscrits

Source

23.02.2025 16:58 👍 0 🔁 0 💬 0 📌 0
Illuminated 12th century Arabic manuscript. The center features a seated woman holding an upturned crescent moon. She is flanked by two other figures in a circle. The circle has two dragon heads protruding from the top. This is all placed within a square which has a figure in each of the corners. Arabic text in blue is at the top and bottom of the figure.

Illuminated 12th century Arabic manuscript. The center features a seated woman holding an upturned crescent moon. She is flanked by two other figures in a circle. The circle has two dragon heads protruding from the top. This is all placed within a square which has a figure in each of the corners. Arabic text in blue is at the top and bottom of the figure.

Check out the Double Dragons near the top of this 12th century manuscript? It's not a video game reference, but believed to be a reference to the pseudo-planet al-Jawzahr which was a dragon that represented the lunar nodes, and would eat the sun/moon as a cause of eclipses.

23.02.2025 15:20 👍 2 🔁 0 💬 1 📌 0
Constellation Mythology: Draco
Constellation Mythology: Draco YouTube video by Astronomy Before the Telescope
22.02.2025 21:23 👍 0 🔁 0 💬 0 📌 0
Post image

Tapestry of the Astrolabes from the Museum of Tapestries and Textiles in Toledo.

15.02.2025 03:34 👍 0 🔁 0 💬 0 📌 0
Astronomical Instrumentation Before the Telescope - Astronomiae Instauratae Mechanica
Astronomical Instrumentation Before the Telescope - Astronomiae Instauratae Mechanica YouTube video by Astronomy Before the Telescope

What did astronomers use before there were telescopes?

04.02.2025 13:50 👍 3 🔁 1 💬 0 📌 0

The "Dissent from Darwin" list. Also included a lot of engineers.

02.02.2025 17:05 👍 0 🔁 0 💬 0 📌 0
Astronomy Before the Telescope Channel Intro
Astronomy Before the Telescope Channel Intro YouTube video by Astronomy Before the Telescope

While I had everything set up for recording a new video, I rerecorded the channel introduction. Amazing how much better it is with a few months of experience.

26.01.2025 02:30 👍 2 🔁 0 💬 0 📌 0
Post image Post image Post image Post image

Tycho Brahe wrote Astronomiæ Instauratæ Mechanica to showcase his instruments to Christian IV of Denmark, as well as potential new patrons. His 1598 edition was extremely limited in copies, and they were hand illuminated. The 1602 trade edition lacked this coloration.

25.01.2025 23:00 👍 0 🔁 0 💬 0 📌 0
"This diagram is primarily used to estimate the solar degrees and is made up of five concentric circles, divided into 12 sections. Each section corresponds to a month, and each month is paired with a zodiac sign. The outermost circle contains the zodiac signs, the second circle shows the additional days that need to be added, the third circle lists the names of the months, and the fourth circle displays the number of days in each month.

Each zodiac sign occupies 30 units, and the solar degree at the beginning of each month is used to calculate the degree needed to reach that specific month. When the number of days in the month is added to the corresponding zodiac degree, it results in the total degree of the zodiac sign."

"This diagram is primarily used to estimate the solar degrees and is made up of five concentric circles, divided into 12 sections. Each section corresponds to a month, and each month is paired with a zodiac sign. The outermost circle contains the zodiac signs, the second circle shows the additional days that need to be added, the third circle lists the names of the months, and the fourth circle displays the number of days in each month. Each zodiac sign occupies 30 units, and the solar degree at the beginning of each month is used to calculate the degree needed to reach that specific month. When the number of days in the month is added to the corresponding zodiac degree, it results in the total degree of the zodiac sign."

🌙 An Ottoman Gelenbevî Circle, crafted in Riq’a script, is an astronomical instrument that features months, zodiac signs, and days of the lunar months, 19th Century (𝗖𝗹𝗶𝗰𝗸 𝗜𝗺𝗮𝗴𝗲 𝗮𝗻𝗱 𝗥𝗲𝗮𝗱 𝗙𝘂𝗹𝗹 𝗶𝗻 𝗔𝗹𝘁 𝗧𝗲𝘅𝘁) #astronomical #history

20.01.2025 00:32 👍 107 🔁 20 💬 0 📌 0

Especially given that Harris had JUST caught Fox deceptively editing footage to misrepresent it and they had JUST settled a 787 million dollar settlement for knowingly lying about the previous presidential election.

17.01.2025 02:14 👍 2 🔁 0 💬 0 📌 0