Harsh Shrivastava

An MIT professor taught the same math course for 62 years, and the day he retired, students from every country on earth showed up online to watch him give his final lecture. I opened the playlist at 2am and ended up watching three of them back to back. His name is Gilbert Strang. The course is MIT 18.06 Linear Algebra. Every machine learning engineer, every data scientist, every quant, every self-taught programmer who actually understands how AI works learned the math from this one man. Most of them never set foot on MIT's campus. They just opened a free playlist on YouTube and let him teach. Here's the story almost nobody tells you. Strang joined the MIT math faculty in 1962. He retired in 2023. That is 61 years of standing at the same chalkboard teaching the same subject to 18-year-olds. The interesting part is what he did when MIT launched OpenCourseWare in 2002. Most professors were skeptical. They worried that putting their lectures online would make their classrooms irrelevant. Strang did not hesitate. He said his life's mission was to open mathematics to students everywhere. He filmed every lecture and gave it away. The decision quietly changed how the world learns math. For decades linear algebra was taught the wrong way. Professors started with abstract vector spaces and proofs about field axioms. Students drowned in the abstraction. Most never recovered. They walked out believing they were bad at math when they had simply been taught in an order that nobody's brain is built to absorb. Strang inverted the entire curriculum. He started with matrix multiplication. Something you can write down on paper. Something you can compute by hand. Something you can see. Then he showed his students that everything else in linear algebra eigenvectors, singular value decomposition, orthogonality, the four fundamental subspaces was just a different lens for understanding what the matrix was actually doing under the hood. His rule was strict. If a student could not explain a concept using a concrete 3 by 3 example, that student did not actually understand the concept yet. The abstraction was supposed to come last, not first. The intuition was the foundation. The proofs were just confirmation that the intuition was correct. The second thing Strang changed was the classroom itself. He said please and thank you to his students. Every single lecture. He paused mid-derivation to ask "am I OK?" to check if anyone was lost. He never used the word "obviously" or "trivially" because he knew exactly what those words do to a student who is one step behind. He treated 19-year-olds learning math for the first time the way he treated his own colleagues. With patience. With respect. With the assumption that they belonged in the room. For 62 years. The result is something that has never happened in the history of education. A single math professor became the default teacher of his subject for the entire planet. Universities in India, China, Brazil, Nigeria, every country with a computer science department, started telling their own students to just watch Strang's lectures. The University of Illinois revised its linear algebra course to do almost no in-person lecturing. The reason was honest. The professor said they could not compete with the videos. His final lecture was in May 2023. The auditorium was packed with students who had never met him before. He walked to the chalkboard, taught for an hour, and at the end the entire room stood and applauded. He looked confused for a moment, like he genuinely did not understand why they were cheering. Then he smiled and waved them off and walked out. His written comment under the YouTube video of that final lecture was four sentences long. He said teaching had been a wonderful life. He said he was grateful to everyone who saw the importance of linear algebra. He said the movement of teaching it well would continue because it was right. That was it. No book promotion. No farewell speech. No legacy management. The man whose teaching is the foundation of modern AI just thanked the audience and went home. 20 million views. Zero ego. The entire engine of the AI revolution sits on top of math that millions of people learned for free from one quiet professor in Cambridge. The course is still on MIT OpenCourseWare. Every lecture, every problem set, every exam, every solution. Free. The most important math course of the 21st century is sitting one click away from you. Most people will never open it.

To save 1 litre of imported crude, India is spending 2,860 litres of groundwater. That's the single statistic missing from the entire E85 debate. E20 is done. The government's draft notification for E85 (85% ethanol, 15% petrol) is ready. Most reactions are either "great, energy independence" or "my mileage dropped." Both are shallow. Here is the actual trade India is making. The economic logic is real: India imports 85%+ of its crude. The FY25 import bill was ~$137 billion. Ethanol blending has already saved ₹1.08 lakh crore in forex and put ~₹92,000 crore in farmers' hands since inception. Every 1% of blending = ~$1 billion in annual savings. But ethanol is not a free lunch: 🔹 Ethanol has 33% less energy per litre than petrol. 🔹 US DoE data: FFVs on E85 get 15 to 27% fewer miles per gallon than on petrol. 🔹 The offset is octane. E85 rates ~105 vs petrol's 91. In purpose-built engines (turbo, high-compression, direct injection), higher octane recovers most of the energy loss. The catch. India's fleet is 90% E10-ready at best. You cannot pour E85 into a Swift. Flex-fuel vehicles need stainless fuel lines, upgraded pumps, 30% larger injectors, ethanol content sensors, and recalibrated engine maps. The hidden cost nobody is pricing: 🔸 E20 at today's consumption needs ~1,016 crore litres of ethanol annually. 🔸 At 2,860 litres of water per litre of ethanol, that is ~2.9 trillion litres of water per year. The annual water footprint of 200+ million Indians. 🔸 E85 scales this 4x+. 🔸 60% of India's ethanol now comes from maize and broken rice. India, a net corn exporter, imported 1 million tonnes of corn in 2024 because of ethanol diversion. 🔸 Retail sugar moved from ₹40 to ₹45/kg in two years partly due to cane diversion. The reframe most people miss: The ethanol programme is not an energy policy. It is an agricultural subsidy dressed as an energy policy. The forex savings are real. The farmer income transfer is real. Both are the actual goals. The mileage drop is a tolerated cost. The water and food inflation risk is the hidden tax. E85 will happen anyway. The listed winners sit in three buckets: 🔸 Sugar and distillery players with integrated ethanol capacity 🔸 Auto ancillaries making ethanol-compatible injectors, pumps, fuel lines, sensors 🔸 OEMs going flex-fuel first (Toyota, Maruti and Hyundai are already prototyping) Energy independence is not free. India is trading barrels of oil for billions of litres of water and millions of tonnes of grain. Whether it's worth it depends on which constraint matters more in 2040 — your oil bill, or your aquifer.

When the media tells you protestors are Naxals or anti-national or backed by a “foreign hand”, what they’re trying to do is kill your middle-class empathy for people struggling for income and dignity of labor. They’re making you dismiss worker’s struggles because they know the day you start thinking for yourself and seeing what a worker’s human condition is, the power structure that benefits the rich will start to weaken. Don’t dismiss workers and what they’re asking for. Look at what they are saying in their own words. And ask yourselves why you’re being told something completely different. You’re a cog in the system that props up the billionaires and their political vassals. Your consent keeps them in power but also allows the state to criminalize protest and unleash violence. Don’t give your consent so easily.

Air India 171 Crash: 260 people died. No final report in 10 months. No action yet against Air India or Boeing. Indigo flights chaos: Indigo plainly declined following the DGCA rules. 4500+ flight cancelled. Thousands suffered. Indigo escaped by paying just 22 CR fine. 60# free seats order: Just weeks after issuing an order, the government tumble down in front of the airline body and paused the order. Strong government my foot!

As per law, sirens and red/blue beacons are permitted only for emergency services. Yet this Honda City is using them openly in Faridabad. I reported this on 0129-2225999, but the complaint was ignored. Now taking this to the public court of Twitter. Please amplify.

There is a mythology the U.S. built around the American War in Vietnam. It goes like this: Young idealistic soldiers were sent into an unwinnable situation by confused politicians. They came home broken and unappreciated. It was a tragedy. A mistake. A lesson learned. Notice what that story does. It centers Americans. Their trauma. Their confusion. Their homecoming. Their feelings. In this story, the Vietnamese people are a backdrop. A jungle. An obstacle. An abstraction. Three million dead Vietnamese people are the scenery for a story about American self-discovery. They made hundreds of movies about Vietnam. The Deer Hunter. Apocalypse Now. Platoon. Full Metal Jacket. Born on the Fourth of July. Hamburger Hill. Count how many of them center a Vietnamese character with a full human life, a family, a name you remember after the credits roll. They turned our genocide into their coming-of-age story. They lost the war and still managed to make themselves the main character. And then, with extraordinary arrogance, they put their soldiers' names on a wall in Washington and call it a memorial, as if the dead to be mourned were the people who flew 10,000 miles to do the killing. Where is the wall for our three million? There isn't one. Because in their telling, we were never quite real enough to mourn.

Homeowner waits until construction job is nearly done—then calls ICE on 6 of her own workers. Woman even provides the ladder used by agent to detain men—who she owes $10,000 for 3 day job. "She called the damn law on us and now we're totally screwed!" men yell in Spanish. "They surrounded us!—They surrounded us!" Agents even left behind the workers' van with doors wide open—filled with thousands of dollars worth of tools. The arrest was broadcast live for about 30 minutes by a co-worker—identified as Bryan Polanco. "Seeing it is not the same as experiencing it," he explains. "I’ve seen many videos, and sadly today I had to experience it." At the end of the video he gets the woman who called ICE on camera: "It is the same woman. Tidying up the house, and still with hatred in her heart." The incident occurred in Cambridge, Maryland.

I’m sorry to say but @airindia maharajaclub is shameful. I’m a platinum member. I was invited by them to attend a lucky Ali concert. They sent me 2 passes, asking who will accompany and I said I don’t know if I will or not as I’m a busy lawyer and will try. I did not attend. They ensured now saying as I did not attend they are deducting 20,000 of my membership points. Even if this was stated this is not an invite to a member but a forced invite. Sorry to say but this is blatant cheating and totally misleading. As a firm believer in @TataCompanies this is totally against the legacy of Tatas. I reserve my right to a customer complaint on this if Air India does not withdraw their absolutely illegal email. Shame on you!

the judi dench cameo fucking sent me 🤣😭

India pays a premium for the privilege of not learning anything :) Every Indian car Tata, Mahindra, Maruti, all of them has a tiny computer inside called an ECU (Engine Control Unit) This computer decides everything - how much fuel to inject, when to shift gears, how brakes work, how the battery behaves in an EV. Think of it as the car's brain. India makes zero of these brains for passenger cars. All of them come from foreign companies, mainly Bosch (Germany). If you don't control the brain, you don't really control the car. Indian OEMs can't even add a simple valve to their own engine without asking Bosch for permission. They can't change a single line of code. They are selling cars with someone else engineering inside. This isn't really about technology being too hard. It's a business model designed to keep you dependent. Three layers lock you in :) First, every new car programme needs Bosch to do setup work (Rs 10-30 crore). Second, you pay full price for software Bosch already developed for Volkswagen so Bosch gets paid twice for the same work. Third and this is the killer every time you want to change anything in the software, even something tiny, it costs around $500,000. So Indian OEMs simply stop trying to innovate. They accept whatever Bosch gives them. The calibration trap means tuning the car's brain for Indian conditions, how should the engine behave in Ladakh cold vs Chennai heat? Indian OEMs outsource even this to AVL in Austria. AVL reuses work they already did for European cars, charges India full price, and transfers zero knowledge. So Indian engineers never even learn how their own cars work from the inside. What Korea did is Hyundai faced the exact same situation in 1987. They set up Kefico as a joint venture with Bosch, learned everything from the inside, and by 2015 they owned the full technology themselves. The sequence was simple - first learn calibration (tuning) → then write your own software → then build your own hardware. It's a ladder. India never climbed the first rung. Why India didn't do this - It's not a talent problem Indian engineers design ECUs at Bosch offices worldwide. It's a combination of things like Indian OEMs won't fund Indian startups to develop alternatives. They demand that Indian suppliers first prove themselves in Europe before getting a chance at home (while European companies protect their own). Middle managers won't risk their careers backing a Pune startup when they can safely pick Bosch. India spends 0.64% of GDP on R&D vs Korea's 4.9%. Private sector funds only 36% of India's R&D, in Korea it's 79%. SEDEMAC - the one exception - One Indian company (IIT Bombay founders, Pune-based) actually makes ECUs for two-wheelers and generators. They have real IP, real patents, millions of units shipped. But even they couldn't break into passenger cars. Tata Motors is literally in the same city and doesn't use them. EVs are simpler to control than petrol/diesel engines. This should have been India's fresh start. Instead, Mahindra's new EV platform has Bosch (Germany), Valeo (France), BYD (China), Mobileye (Israel), Continental (Germany) - zero Indian ECUs. The dependency just migrated from ICE to EV with different foreign names. swarajyamag.com/technology/the…

Yesterday, on the way to rafting, guide told us to leave all our gear on the road before going down to the riverbank to get the boat. One lady was carrying a cold drink bottle while walking from the road to the river bank, which is hardly 50 m away. I asked her to finish it on the road itself because there are no garbage disposal facilities on the river bank. She completely ignored me and eventually threw it on the bank. No matter how much we blame the government, if civilians don’t have civic sense, we will end up turning every city and beautiful place into garbage.

@Bhairavi_Jani @vtchakarova Those that will hit us? Even more worrying.

@vtchakarova Couldn’t agree more. As a supply chain business owner i see disruptions happening now and those that will hit us in a few weeks - unprecedented.

I’ve been through four systemic risk-induced crises so far: GFC, Covid, Russia/Ukraine, & now this. This is by far the worst! I’m just devastated by the imagination of the global impact, the human loss, the severe poverty crisis & the political turmoil that are about to hit us.

@KumaraGuru PM Museum.

Where in Delhi is this?

Bought an AC from Daikin. Thought It would do things “properly” this time. Paid 2x for their official AMC....peace of mind, right?Then the story begins… Visited the same center from where I bought AMC → “Sir, raise complaint online.” Raised it online → got assigned a different center. That center → “Sir, AMC wala center will handle this.” Back to square one. 3 touchpoints. 0 accountability. If this is the experience after paying a premium, what’s the point?Big brand, but no clear SOP. @DaikinIndia please fix this. Customers shouldn’t be doing ping-pong for basic service.

Never ever take a travel policy from @policybazaar I took a @CareHealthIndia travel policy from Policybazaar. My flight from Dubai got delayed by more than 4 hours (Jan 2026). I put in a claim as > 4 hours delay, a compensation was to be paid as per policy document. And then the nightmare started. They asked for some docs, which I sent. Policybazaar RM follows up. They keep calling that Care Insurance requires more docs. I tell them it is too much an hassle and I don't want to pursue the claim. But they pursue me to send the docs and they will do the followup with Care. Policybzaar keeps calling and I do give the docs. All that are required. As claim amount is not worth the docs they keep on asking everytime, I decide not to pursue. Care keeps asking for already sent documents. Policybazaar has no clue. Each time different RM calls. I tell them don't call me. But I keep getting calls. And Care keeps sending mails and SMS asking for docs already submitted. It seems Care doesn't want to pay. Fine, I have learnt my lession. I will never buy again from Care and Policybazaar. I don't want the claim. Stop the harassment. Please don't call me again.

@bajajlife_in , your service has to be the worst in India. Absolutely ghastly. I am sick and tired of your staff not attending to any queries and sick and tired of screaming and shouting on social media. Honestly, never across service as terrible as that provided by LajpatNagar branch in New Delhi. Will never recommend @BajajLife to anyone

@Mahishini @r_evarts Oh i have Pelikan ink too! And its fountain pen as well!

@r_evarts Still with bottled ink 😇

Who remembers using this in school?

There is an invisible layer that affects many friendships in Bengaluru. That layer is called urban and civic exhaustion. Friendships don’t fade because people don’t care. They fade because the city quietly drains the energy required to sustain them. The traffic takes an hour out of your evening. Work spills into what used to be personal time. Weekends become recovery periods rather than social ones. You start saying things like: “Let’s meet soon.” “Next week for sure.” “Once things settle down.” Things rarely settle down. What earlier required a 10 minute auto ride now requires planning, coordination, and stamina. You have to build stamina to be rejected by drivers on apps, to cross under constructed sites, to take long jumps over open drainages and collect dust on your face. Friendships slowly move from physical spaces to WhatsApp reactions and Instagram replies. The affection is still there. The intent is still there. But the civic friction of the city sits between people. In cities like Bengaluru, maintaining friendships has quietly become an act of effort. And sometimes, effort is the first casualty of urban and civic exhaustion.

@Bharati09 I like the “homogenized public taste”! So true. Glad you bought that up.

Open Kitchen. Sandesh making in the iconic Girish Chand Dey & Nakur Chand Nandy confectionary store, in Kolkata. A relief to be in a city where Haldiram’s hasn’t ruined affordable Indi mithai stores or homogenised public taste.