Steve-o Stonebraker
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sstoneb.bsky.social
Steve-o Stonebraker
@sstoneb.bsky.social
700 followers 1.5K following 1.3K posts
Your basic child of the 80s nerd. I love #Transformers and #ITeachPhysics in Massachusetts.

Posts prior to July 2023 were imported from Twitter using BlueArk's service.

Mastodon: https://retro.pizza/@sstoneb
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sstoneb.bsky.social
Just shoving the sensor right up against the tube since luckily the hook fits inside it, and swinging with one hand on sensor and other on the tube, holding them together.
Physics class equipment, a sensor with string tied to it passing through a plastic tube and tied to a rubber stopper. Physics class equipment, a sensor with string tied to it passing through a plastic tube and tied to a rubber stopper. The tube is pressed flush against the sensor.
November 5, 2025 at 2:22 PM
sstoneb.bsky.social
#ITeachPhysics I'm trying a variation on a circular motion lab @joemilliano.bsky.social has written about before, using a force sensor while spinning things around on strings. The "good" part of this test from 10-20 s still shows a big variation in force. Do other people get similar results?
November 5, 2025 at 2:18 PM
sstoneb.bsky.social
In the 90s when I was in college I read "The Winner-Take-All Society" by Frank & Cook (1995) for an econ class. It had this passage about the "Lake Wobegon effect" which has always stuck with me:

"60% thought they were in the top 10%, and 25% thought they were in the top 1 percent."
Photo of a page from "The Winner-Take-All Society" by Frank & Cook. It has yellow and pink highlighting. The text reads: Studies have found that most people think they are more intelligent and better drivers than the average person. Workers asked to rate their productivity on a percentile scale relative to their coworkers responded with an average self-assessment of being in the 77th percentile, and more than 90 percent felt they were more productive than the median worker. More than 70 percent of one million high school seniors reported in a survey that they had above-average leadership ability; only 2 percent saw themselves as below average. When asked about their ability to get along with others, virtually all of those same students said they were above average; 60 percent thought they were in the top 10 percent, and 25 percent thought there were in the top 1 percent. Another survey revealed that 94 percent of university professors thought they were better at their jobs than their average colleague.
November 1, 2025 at 3:27 PM
sstoneb.bsky.social
Bonus units of measure content for cool science people. #ITeachPhysics #ITeachMath

I did not know until reading that ice harvesting sign that air conditioner ratings being in ‘tons’ literally harkens back to ‘how big of a block of ice is this equivalent to?’
Closeup of a sign reading: Ever wonder why air conditioning capacity is measured in tons? It has nothing to do with the weight of the au conditioner. Before modern air conditioning wa invented, people used blocks of ice to cool building Air was moved across large blocks of ice and chilled before being blown into rooms making them more comfortable. As ice was sold by the ton, it was learned that it takes about 12,000 BTUs - that's British Thermal Units, to melt one ton of ice over the course of 24 hours. As home-cooling methods switched from ice to more modern air conditioning, professionals in the industry continued to measure the amount of heat that an air conditioner can remove from a building in terms of tons of ice.
October 17, 2025 at 5:44 PM
sstoneb.bsky.social
Always read the plaque.
A sign with a very long and detailed history of Lake Williams in Marlborough Massachusetts. Too long to fit into this alt text. A sign with a long narrative about New England lake ice harvesting in the 1800s. Too long to fit into this alt text. A sign with a long discussion of ‘glacial erratics’, boulders transported great distances by glaciers in the past and deposited in random places.
October 17, 2025 at 5:38 PM
sstoneb.bsky.social
Batch number two
Remains of an old stone wall running up a hillside in the woods Wooden planks running along a path in the forest A branch of vibrant red leaves overhangs a lake with the stony shore in the foreground Thick vines in a forest twisted in a tight spiral around other vegetation
October 17, 2025 at 5:29 PM
sstoneb.bsky.social
Some of the views so far…
Boardwalk extending over a lake Courthouse peeking out above autumn foliage, seen across a lake Boardwalk extending over water leading into forest Sun shining through yellow leaves and trees
October 17, 2025 at 3:51 PM
sstoneb.bsky.social
October 17, 2025 at 9:34 AM
sstoneb.bsky.social
Made a couple small changes to my potential energy function U(x) simulation: tangent line now doesn't change size as much, removed a bug in the velocity display, added "reverse" and "return" buttons into the main graph area. Same link:

www.desmos.com/calculator/e...

#ITeachPhysics #desmos
October 16, 2025 at 4:58 PM
sstoneb.bsky.social
Javalab has so much great stuff. I like how you can put masses between the springs in this!

Would be nice if it were possible to adjust the k values, though. Maybe we need a Desmos version after all...
A screenshot from the javalab.org "connection of springs" simulation. A spring hangs from the ceiling with a hooked mass at its bottom. Handing from that mass is another spring and then another mass.
October 16, 2025 at 3:53 PM
sstoneb.bsky.social
I uploaded my first #college recommendation letter of the year last night, and discovered that #Naviance (the platform many schools use to submit college applications to the Common App program) now has an LLM-based "assistant" for writing these rec letters. #EduSky
Part of an online flyer from PowerSchool's Naviance platform. It reads: AI Powered Letter of Recommendation EFFORTLESS LETTERS OF RECOMMENDATION WITH AI ASSISTANCE Naviance’s AI-powered Letters of Recommendation tool helps teachers quickly create personalized, high-quality letters using existing student data. It supports privacy, flexibility, and full editorial control, addressing time constraints, large caseloads, and incomplete profiles.
October 15, 2025 at 9:52 AM
sstoneb.bsky.social
Listened to this @99pi.org yesterday:
99percentinvisible.org/episode/641-...
Roman's discussion at around 19:00 about how designing for efficiency can be BAD really made an impression on me.

Specifically, the bit about how (supposedly) making advertising more efficient destroyed journalism.
A screenshot of a transcript from 99 Percent Invisible, spoken by Roman Mars. The text reads: But the one that’s sticking with me–and this is gonna be kind of abstract, and I don’t know if this is going to come off well–is the idea of the march to make things more and more efficient makes the world a worse place. And I think of that in terms of advertising. The idea that we were going to efficiently measure how effective advertising was through clicks and eyeballs and stuff erased all of the extra money that made all the journalism and all the pop culture that you cared about in the 20th century–it made it all possible. The inefficiency of the advertising system made everything good in this world. I think that the idea that you’re trying to get things to be as efficient as possible is actually a terrible world-destroying idea. The most efficient restaurant is a ghost kitchen that has no storefront because that’s inefficient because it could be empty sometimes. And it’s a ghost’s kitchen that just ships you a thing and has an underpaid delivery person and brings it to your door and you never leave. And this is stripping away all the goodness of the world in those cities. I think efficiency is absolute garbage, and that is the design-related hill I’m willing to die on. I feel like you should always be allowing for great deals of inefficiency to make a nice designed city–a nice designed system–and make it work. I really hate the focus on efficiency. Not only does it destroy all these good things, it takes money and gives it to the worst people–the platform creators and the tech people–instead of all the loose, empty change and tips and things. And it’s not like things are cheaper or things are better. Money is being transferred to the wrong people instead of creators and people who make the world a better place through community and creation.
October 11, 2025 at 1:02 PM
sstoneb.bsky.social
#Astronomy #AstroEdu I'd like to get a celestial sphere model where a tiny Earth is mounted inside a transparent sphere with stars, coordinates, etc. marked on it. The one I see listed almost everywhere is by EISCO who are a fine company, BUT... half the reviews of it on Amazon are terrible:
Photo of the EISCO celestial sphere model. A transparent sphere is mounted on a tilted axis. The sphere has stars marked on it. In the middle is a small globe of the Earth.
September 14, 2025 at 7:24 PM
sstoneb.bsky.social
I occasionally post in #ITeachPhysics spaces about the simulation site Javalab.Org by DongJoon Lee. Today I stumbled across this sim of his with a hilarious cartoon strongman to illustrate the very high tension needed to suspend a weight from a nearly-horizontal string:

javalab.org/en/addition_...
A cartoon strongman with a ridiculous moustache pulls on two ends of a string with a phone book dangling from the middle of the string.
September 12, 2025 at 5:18 PM
sstoneb.bsky.social
It's a new year at school, which means new discoveries of students who are big fans of old media you wouldn't think they'd have even heard of. This is a capture I sniped through lanschool of a student's MS Paint rendition of Booster Gold, which he drew without reference! #boostergold #dccomics
A low-res screenshot showing a digital drawing of Booster Gold surrounded by the MS Paint interface.
September 5, 2025 at 7:09 PM
sstoneb.bsky.social
Seeing so many articles about Saturday's lunar #eclipse that seem to be targeting American readers *even though the eclipse will not be visible from the Americas*. Buried a few paragraphs into the article they list where you can see it from.

This blunder by People takes the cake, though:
Screenshot of a news article about a lunar eclipse. The article has a photo of a solar eclipse and has captioned it "lunar eclipse".
September 5, 2025 at 12:51 PM
sstoneb.bsky.social
When I was out of the classroom, one of my students snuck in and left two baggies of Canadian potato chips next to my lunchbox for me. 💛
Two zippy bags with different types of potato chips sit next to a ninja turtle lunchbox and a package of oreos.
September 4, 2025 at 3:18 PM
sstoneb.bsky.social
I know many thousands of people will have seen this broken sign gag in the game Death’s Door before me, but it was new for me just now and really wanted to share it. What a fun, silly thing to put in. #DeathsDoor
August 19, 2025 at 11:48 PM
sstoneb.bsky.social
In my google searches I use the garbage-removing "udm=14" query, but here's an "AI mode" tab front and center. Also this Sheets-related search has a tab for Flights(???) and the Images tab (which is what I wanted) has been moved under More.

The tabs DO change depending on your search terms.
A screenshot showing the top of a google search for "google sheets importrange permissions". Between the search bar and results are tabs reading "AI mode", "All", "Forums", "Short videos", "Flights", "Videos", "Web", and lastly "More" which shows a dropdown list arrow.
August 18, 2025 at 1:15 PM
sstoneb.bsky.social
I continue to find the @puzzmo.com crossword clues incredibly delightful.
A crossword puzzle clue reading: “BLANK up the jam, BLANK it up, while your feet are stomping and the jam is BLANKing, look ahead the crowd is jumpin’” (“BLANK up the jam” lyrics)
August 11, 2025 at 12:58 AM
sstoneb.bsky.social
Optional markers for the contact points, and if you dig into the nuts & bolts you can even choose your star's color, including any magical star hue from 0-255. ;) I stopped myself from assigning the color to a blackbody temperature function for realistic colors only.
Screenshot of a Desmos graph showing two intersecting circles that represent a star and exoplanet in transit in front of the star. Contact points and intersection points are marked.
August 7, 2025 at 4:19 PM
sstoneb.bsky.social
View a simple "exposed area" curve with a flat bottom OR a more advanced curve that incorporates a limb-darkening model. There are pedagogical pros and cons to both!
Screenshot of a Desmos graph showing two slightly-different curves with a dip in them. One is smoother and deeper, while the other has a flat bottom.
August 7, 2025 at 4:19 PM
sstoneb.bsky.social
Finished(?) another #desmos graph that I've been poking at for a few years, mostly in the days surrounding when I teach this topic each year: #exoplanet light curves.

Easily adjust the star and planet radii AND impact parameter.

#astronomy #physics #exoplanets #ITeachPhysics
Screenshot of a Desmos graph which simulates the light curve brightness dip as an exoplanet transits in front of its star.
August 7, 2025 at 4:19 PM
sstoneb.bsky.social
Hey @desmos.com is there any chance the font in "note" expressions could be changed to something with at least some serifs? The lack of differentiation between big-eye and small-ell, for example, is a problem when writing a note about a function like I(l). The math expressions are fine, ofc. #desmos
A screenshot from the Desmos calculator interface. Two expression entries are visible. The first entry, which is in math-mode, shows a serif font containing a number one, a capital letter "eye", and a lowercase letter "ell". They all appear distinct from each other due to serifs. The second entry which for a text or "note" field contains the same characters, but the two letters are now indistinguishable. The number is still distinct from the letters.
August 7, 2025 at 1:52 PM
sstoneb.bsky.social
While working on my last #desmos graph I ran into a couple quirks with its implementation of arctan(theta), the most mysterious of which is this interaction with lists. The exact same expression gives different results depending on use of a value in parentheses vs a list element:
Two expressions in the Desmos calculator. The both involve arctangent of one over zero, but written in slightly different ways. One evaluates to positive pi over two and the other negative pi over two.
July 30, 2025 at 1:38 PM