Stefan Meyer

@justinskycak @_MathAcademy_ @exojason @ninja_maths Hi @_MathAcademy_ , did you just add a new 6th grade math course? Is that replacing the existing Pre-calculus course?

Role of Teachers in the Math Academy Classroom New @_MathAcademy_ podcast episode with @exojason & @ninja_maths, posted here and everywhere else (see comment) 00:00 - Introduction 02:56 - What is the teacher’s role alongside Math Academy? 05:37 - Math Academy frees up teachers to do the human parts of teaching 07:03 - Projects are great if students have the prerequisite skills 07:42 - Drills without context are boring 08:43 - Games without skills are inefficient 11:14 - Build fun activities on top of a solid foundation of skills 12:15 - Teachers can tailor the class to the students’ preferences 13:28 - Implementing mastery learning is too much work for a single teacher 15:27 - Doing projects without prerequisites is frustrating 16:57 - True empowerment is giving kids the skills they need to succeed 19:30 - Missing skills compound in hierarchical skill trees 24:06: Lack of automaticity in lower level skills slows down higher level tasks 27:14 - The MA team builds and improves courses through experience 29:21 - The MA team targets tasks with low pass rates for additional scaffolding 31:03 - Alex built knowledge graph intuition through years of experience 37:40 - Social media enforces hyper-accountability 39:19 - Differential equations courses are often a hodgepodge of disjointed techniques 43:20 - Math Academy university courses are a superset of elite university content 45:18 - Differential equations is a highly branching subject 49:21 - The breadth of Differential Equations makes it often poorly taught

@ChrisO_wiki @akarlin I’ve been hesitating because of reviews like these.

@akarlin I tried reading WoT, but gave up halfway through the first book. It was so badly written that it made me wonder if it even had an editor.

What I find interesting is that not only LOTR (150M+ books sold) but ASoIaF (90M; unfinished) generate 10-100x more memes, discussion, and "bait" than Wheel of Time (90M), which by sales and peak popularity is firmly part of the fantasy genre's Big 3. Back in the day you had a vast amount of theorycrafting discussions about the metaphysics of the One Power and the Dark One's prison and the World of Dreams and so forth so it's not as if you're starved for content! I think the banal problem is that Robert Jordan was just singularly unlucky with adaptations. The IP was squatted on by grifters, and then defiled by an idiotic hack in the belated TV adaptation. Hence it never got a chance to explore into the popular culture like Tolkien's and GRRM's worlds. You can have various opinions on D&D, and yes I agree they went downhill hard after the source material ended, but everything is relative in life and they are conscientious geniuses compared to Rafe.

@jasonamartineau Fascinating, depending on distance you get different times (obviously but just good to see it play out). I’m closer and it was less than second between them

Impressive. The earthquake warning that showed up on all of my Apple devices was a good 20 seconds before it actually hit.

@vrexec @jason334990 1) break even historically was 7 years 2) standard deduction -> usually property taxes+ income, so tax benifits still are full or close to full value 3) the real value is over 20-30 years

@jason334990 standard deduction eats into most of the tax benefits

I'm doing some back of the envelope math on buying vs renting. Say you buy a $1M house with 20% down at about 6% mortgage rate and plan to stay there for five years. Your principal paydown in the first five years is about $57,000, but you've paid about $230,000 in interest. You've also paid roughly $100,000 in property taxes, insurance, and maintenance. Say the house appreciated 2.5% every year — so when you sell it's worth about $1.13 million. Your all-in costs to sell are about 7.5% — brokerage commissions, transfer taxes, attorney fees, title insurance, and the inevitable post-inspection negotiation. On a $1.13M sale that's about $85K in fees. So you net about $1.046M. You still owe $743K on the mortgage. You walk away with about $303K in cash — your $200K down payment back, your $57K in principal, and about $46K in net profit from appreciation. Your non-recoverable costs — interest, property tax, insurance, maintenance — were about $330K over five years, or about $5,500/month. That's your effective rent. But you "made" $46K selling, or about $770/month — so your effective rent was about $4,700/month. Not bad, but you tied up $200K for five years to get there. And if appreciation was 1.5% instead of 2.5%, that net gain basically disappears and you're paying $5,400+/month in effective rent. And this assumes there's appreciation at all — and that something doesn't go wrong with your house that needs a major remodel or repair. On a five-year horizon at 6% rates, you need everything to go right on appreciation just to make ownership competitive with renting. The transaction costs eat most of your upside. What am I missing? Anything?

@mzjacobson Looks like we already could do 12 hours 100% if wanted to. If batteries double, will it spread evenly over night or will is shutdown gas completely in evening?

Every day is the same >100% WindWaterSolar powering California's main grid for part of the day for 37 straight and 64/87 (73.5%) days in 2026 Gas is down 59.2%, solar is up 75.4%, batteries up 333% in '26 v '23 Batteries have provided 8% of all electricity output in CA in 2026

I've never sen anything more accurate

@potatoslav We lost dinner place mats (kid ones with cars and Dino’s etc) How do you misplace those? We looked everywhere, even considered friends comming over and taking them. Few months later cleaning lady lifts up edge of rug for some reason and bam. lol.

baby lost our remote. has been lost for days. we finally found the backup remote that has the batteries removed that we gave him so he would stop stealing our primary remote and had to confiscate it and put batteries back in so that we can use the TV. every time we ask where he put the remote he laughs. owned by baby.

@uubzu @skatetapes He isnt wrong though.

@skatetapes You sound so interesting

Chat, is this true

@mr_james_c How many EVs of battery is that?

The battery capacity to provide Britain with 2 weeks of electricity during winter would cost more than £2tn. Which is 20x the cost of building enough nuclear power stations to provide all the UK's electricity needs.

@MadelaineLucyH They still do that at 16. I hoped it ended sooner.

I know a 16 year old girl. She’s tall, she could easily pass for being 25-30 in the right outfit. And she’s A KID. She cries because she has to lay the table for dinner. She screams at her dad for not letting her buy more make up. She gets unbelievably upset about what Chloe said in Spanish. She storms off when her sibling gets a bubble tea and she doesn’t. I cannot IMAGINE dating a teenager. It’s just so, so gross. However old she “looks”, that’s a kid.

@Flyingfishtrump @leRaffl Sigh. Just too slow. :(

@stefan_meyer98 As my model is based on @LeRaffl's extrapolations of market share, not until he adds California to his model. But my gut feeling is it will be very close to the UK curve.

@JHB_econ lol, you have already disqualified yourself from sage wisdom to the innumerate. I need guidance for to help answer questions like why are you doing this to me? Why learn when you can just use calc?

@stefan_meyer98 We’re using art of problem solving (beast academy line for younger grades). I’m not promising they’re not math Olympics kids, though, as a former mathlete myself 😆

I was surprised by this bc math education at my kids’ school is so bad I’m supplementing at home. & then I got to the end of that sentence & realized they have their own personal math tutor with a BS in Math & Econ PhD & maybe we’re not the only ones doing math outside school…

@racerdogjack @KelseyTuoc @mattyglesias We use mathacademy. I’m actually not unhappy with public school teaching it’s just too slow, with minimal effort and very unmotivated child, my daughter can go at least 2x faster than glass.

@KelseyTuoc @mattyglesias We used RSM and other enhancements for our San Francisco public School kids, and many of our friends did also. Dumbing down math in public school creates a two-tier system.

@SimonMahan Solar is on track to go double by 2030 in Texas. That 15% will mostly cut into gas.

Here's power generation in Texas this past year. You can see gas is still really important during summer. Still, 24% wind and 15% solar for the past year is pretty incredible. Lots of room for solar+wind growth. Check out the EIA dashboard, it's awesome: eia.gov/electricity/gr…

@Newsarea247 @ok6ixx The interesting thing is that the people (at least one) who was nice to him remembered it for the rest of there life.

@ok6ixx He’ll probably remember that for the rest of his life. Being accepted like that can mean everything.

When I was a freshman in high school there was a boy named Chris who was a senior who had autism and he really loved Hotwheels. He always wanted to show people his tiny cars and instead of the popular crowd making fun of him they got excited with him. On his birthday everyone bought him Hotwheels and he went home with a backpack full of them. For homecoming they voted him king and gave him a cape with Hotwheels on it. Sometimes high school isn't so bad.

@RonKarpel @nicolasfulghum Missed a few zeroes. It’s 1000twh addition per year. And fossil fuel is only 60%. So it’s only about 10-15 years to fully replace it depending on growth and grid constraints

@nicolasfulghum Grok: How many TWh of electricity are generated world wide in a year? around 31,000–31,500 TWh for 2024 1TWh out of 31,000? You got a long way to go.

NEW | The world installed a record 814 GW of solar and wind capacity in 2025 ☀️⚡️ That's over 1,000 TWh of electricity generation per year... ...enough to displace nearly twice Qatar's annual LNG export volume in gas generation 🔥❌ Fossil fuels crisis? Wind and solar deliver.

@johnson_wrjohn1 @clawrence I don’t understand why you say solar isn’t charging batteries? If nat gas isnt needed durring day and changes batteries it’s only because solar was there. Eventually gas will be curtailed when it because less economic as solar grows, especially in spring first. Right?

I am afraid you are wrong. As the graph shows, the contribution of storage to the grid over the past 3 years is just a tiny fraction of hydrocarbons (mainly gas). Also, note the trend in storage. It is growing at a glacial rate. It is highly unlikely that will change any time soon. Every month, I publish a set of Key Performance Indicators for Texas that tracks the Path to NetZero You can check it out at: wrjohn1.substack.com/p/texas-ercot-…

Battery storage in ERCOT is now routinely providing 10%-20% of power required by the Texas grid during times of peak demand. Five years ago, we had no batteries in ERCOT. The next 5 years are going to be nuts.

@johnson_wrjohn1 @clawrence That graph seems less positive. Thanks

@stefan_meyer98 @clawrence FYI, California is not doing much better than Texas. They are not really making much progress on getting rid of High-Carbon Generation. You can check out their Key Performance indicators at: wrjohn1.substack.com/p/california-c…