mathheadinc

Teaching, tutoring math and calculus, with enthusiasm and an ever present sense of wonder, to students 6 & up since 1995. Anyone can learn anything!

[mathheadinc @mathheadinc]

TEACHING REQUIREMENTS: Fearlessness, grit, knowledge, skill, compassion, kindness, determination. #edchat #mathchat

[mathheadinc @mathheadinc]

@john_seelke @HappyTeach98249 @rastokke @MrZachG @sarahpowellphd A 6-year-old with only the ability to count can learn infinite series! It doesn’t take much for kids to learn higher concepts, algorithms, pattern recognition, etc.

[mathheadinc @mathheadinc]

@glezak We could have used some of that rain 🤣

[mathheadinc @mathheadinc]

@cdtwriter @LadyChuan SAME!!!!!!!!!!!

[mathheadinc @mathheadinc]

@PennyDellPuzzle Obfuscate
Gallantly
Earthworm

[Wolfram @WolframResearch]

Draw it. Compute it. Analyze it. ⚛️
#WolframLanguage function MoleculeDraw converts your sketches into computable molecular objects.
Try it today.
🔗👇

[mathheadinc @mathheadinc]

#Petrichor is the name for the earthy smell after rainfall. There should be a name for the metallic smell after turning on the furnace for the first time in the fall.

[mathheadinc @mathheadinc]

Tutoring from the basement is always fun 😝Stay safe everyone #kcwx #mowx #tornadowarning

[Massimo @Rainmaker1973]

Gilbert Strang, an MIT professor, taught the same linear algebra course for 62 years. When he delivered his final lecture in May 2023, students from around the world tuned in online to watch.

The course is MIT 18.06 Linear Algebra. Millions of machine learning engineers, data scientists, quants, and self-taught programmers learned the essential math behind AI from his clear, free video lectures, even though most never stepped foot on the MIT campus.

Strang joined the MIT faculty in 1962 and retired in 2023. When MIT launched OpenCourseWare in 2001–2002, he was one of the first to embrace it fully. While many professors hesitated, Strang saw it as an opportunity to share mathematics with everyone. He filmed his lectures and made them freely available.

He completely changed how linear algebra is taught. Instead of starting with abstract vector spaces and proofs, Strang began with something simple and visual: matrix multiplication. He built intuition first using concrete examples, then introduced more advanced ideas like eigenvectors and singular value decomposition. He insisted that students should be able to explain every concept with a small, tangible matrix before moving to theory.

Beyond the content, his teaching style stood out. He spoke to students with genuine respect, patience, and kindness, never using words like “obviously” or “trivially.” He regularly paused to check if anyone was lost and treated beginners as thoughtfully as he would his colleagues.

As a result, Strang became the default linear algebra teacher for much of the planet. Universities in many countries began recommending his lectures to their own students. Some even replaced their in-person courses with his videos because they could not match their clarity.

His final lecture ended with a long standing ovation. Strang seemed surprised by the applause, smiled humbly, and simply thanked everyone.

In his short comment under the YouTube video, he expressed gratitude for a wonderful life of teaching and hoped others would continue teaching the subject well. No self-promotion, no grand farewell—just quiet sincerity.

When you add up every version, every upload, help sessions, and all the different recordings MIT has shared over the years, the total has surpassed 20 million views.

Today, the full course, including all lectures, problem sets, and solutions, remains freely available on MIT OpenCourseWare. One of the most important mathematical foundations of modern AI is still just one click away.

[mathheadinc @mathheadinc]

@smith_john96806 @maolesen Or see the movie?!!! Information on the dangers of radium is EVERYWHERE!!!!! Yikes 😬

[Star Walk @StarWalk]

✨ Venus meets Mercury in the evening sky!

On October 5, Venus and Mercury will reach conjunction, appearing close together above the western horizon after sunset.

🌟 Venus will be impossible to miss at magnitude –4.6, while Mercury will shine at magnitude 0.0. At the moment of conjunction, the two planets will be separated by about 5°28′ — roughly the width of 11 Full Moons lined up across the sky.

And the show doesn’t end there: on October 7, Venus and Mercury will reach their closest apparent distance, coming within 5°02′ of each other.

📅 Conjunction: October 5, 2026, at 14:50 GMT
🔭 Closest approach: October 7, 2026, at 04:09 GMT
🌅 Best time to look: after sunset, low above the western horizon

The view strongly favors observers in the Southern Hemisphere, where both planets will stand higher in the evening sky. From northern latitudes, the pair may be very low — or already below the horizon — by the time the sky becomes dark enough.

Remember: Venus and Mercury only look close from our point of view. In space, they remain millions of kilometers apart.

Save the date and look west after sunset! 🌅🪐

[mathheadinc @mathheadinc]

HA! I never gave them up 😝

[Harvey G. Cohen @CultrHack]

People are now apparently returning to CDs and DVDs for “the security of knowing they have a physical copy of their fave films & music, free from algorithms, interruptions and vagaries of streaming.” I’ve heard this from my students for a while. Me too.
https://t.co/iuqc6wCqNt

[Hubble @NASAHubble]

Just passing through...

Today, Earth's orbit passes between the Sun and Saturn. That means Saturn is opposite the Sun in our sky, so it's at "opposition" – the perfect time to catch a glimpse of the ringed planet.

For more October skywatching tips: https://t.co/IJbLPf5zuY

[Kirk Borne @KirkDBorne]

Download 698-page PDF >> Everything You Always Wanted To Know About Mathematics*

(*But didn’t even know to ask)

A Guided Journey Into the World of Abstract Mathematics and the Writing of Proofs ➡️ https://t.co/JLsDOmqmQY

[Star Walk @StarWalk]

🌙 Three bright dots. Four mornings. A different view each day.

From October 4–7, watch the waning crescent Moon move past Mars, Jupiter, and Regulus — a bright star in Leo. Together, they’ll trace a gentle curve above the eastern horizon before sunrise.

📅 FOLLOW THE MOON

• October 4: The Moon approaches the lineup.
• October 5: Look for reddish Mars near the Moon.
• October 6: Brilliant Jupiter becomes the Moon’s neighbour.
• October 7: The thinner crescent appears near Regulus.

✨ WHICH DOT IS WHICH?

Jupiter is the brightest of the three. Mars has a warm, reddish tint, while Regulus shines blue-white. All three are visible to the naked eye!

🌍 WHERE TO WATCH

The Northern Hemisphere gets the better view, with the formation climbing higher before sunrise. From the Southern Hemisphere, Regulus stays low, so find a spot with a clear eastern horizon.

Open Star Walk 2 to identify each object and check the view from your location.

Save this guide and try watching on more than one morning — the Moon’s changing position is part of the show! 🌙

[Abakcus @abakcus]

I curated 125 free math textbooks, written by the mathematicians who teach the courses and shared on their own university pages. No sign-up, no paywall, no pirated copies. From high school algebra to graduate analysis. 👇

https://t.co/2RHmcXLYMH

[mathheadinc @mathheadinc]

@leahmcelrath TRUTH!

[Star Walk @StarWalk]

October 2026 is a beautiful month for stargazing 🌌✨
⁠
Here are the celestial events you shouldn’t miss:
⁠
✨ October 2 — Moon, Betelgeuse, and Aldebaran
⁠
🪐 October 4 — Saturn at opposition
Saturn will be at its brightest and visible all night long. This is the perfect time to observe the planet and its famous rings through a telescope.
⁠
🌙 October 4–7 — Moon, Mars, Jupiter, and Regulus
The Moon will pass along a beautiful line formed by Mars, Jupiter, and Regulus.
⁠
🌙 October 6 — Moon and Jupiter
This lunar occultation will be visible for observers in parts of North America under a dark pre-dawn sky. Even if the occultation itself isn’t visible from your location, the Moon and Jupiter will still appear extremely close together.
⁠
⭐ October 7 — Moon and Regulus
⁠
☄️ October 9 — Draconids peak
⁠
☿ October 12 — Mercury at greatest eastern elongation
A good chance to spot Mercury in the evening sky.
⁠
⭐ October 14 — Moon and Antares
⁠
☄️ October 21 — Orionids peak
One of October’s most famous meteor showers reaches its maximum! This year, moonlight may interfere a bit, so the best time to watch is in the pre-dawn hours.
⁠
✨ October 25 — Moon, Saturn, and Algenib
A beautiful geometric meeting in the sky: the nearly Full Moon, Saturn, and Algenib will form a neat triangle.
⁠
🌕 October 26 — Full Hunter’s Moon
October’s Full Moon is known as the Hunter’s Moon — the Full Moon that follows the Harvest Moon. It will look especially beautiful around moonrise, when it may appear larger and take on a warm orange tint near the horizon.
⁠
✨ October 26 — Jupiter, Mars, and the Beehive Cluster
⁠
🌙 October 28 — Moon and the Pleiades
⁠
✨ October 29 — Moon, Betelgeuse, and Aldebaran
⁠
Save this calendar so you don’t miss the best nights for stargazing! 🔭✨
⁠
Please note that the calendar dates are given in GMT and may vary depending on your time zone.

[mathheadinc @mathheadinc]

@ThisAmerLife That’s HILARIOUS!

[mathheadinc @mathheadinc]

@Dirtdragonmom Folks from small town Missouri pronounce it this way!

[mathheadinc @mathheadinc]

@chefsevenn Pour off a bunch of that juice! Ham hock, bacon, a smidge of FISH SAUCE, a ton of caramelized onions, paprika, black pepper, red pepper, salt to taste.