Elon Musk says steel killed carbon fiber on Starship at one-fiftieth the cost.
Carbon fiber was supposed to be the future of rocketry.
Lighter than aluminum. Stronger than steel. Trusted by every Formula 1 team.
SpaceX picked it for Starship.
"Particularly if you go for a high-strength specialized carbon fiber that can handle cryogenic oxygen, it's roughly 50 times the cost of steel."
Then progress stalled.
The autoclaves needed to cure the resin had to outsize every autoclave on Earth, and the team couldn't even produce a clean barrel section without wrinkles.
Musk, watching the Mars timeline slip:
"At this rate, we're never going to get to Mars. So we've got to think of something else."
So he asked the question nobody at SpaceX had asked: "What about steel?"
It became known as the **cryogenic stainless flip**.
Musk, who had already shipped Falcon 9 in aluminum-lithium, broke with the textbook.
"When you look at the material properties of stainless steel, full-hard, strain hardened stainless steel, at cryogenic temperature the strength to weight is actually similar to carbon fiber."
Starship ran on cryogenic methane and oxygen.
The airframe lived at temperatures that flipped steel ahead of carbon fiber.
"You could smoke a cigar while welding stainless steel."
After Musk made the call, steel weighed less than the carbon fiber version.
Fifty times cheaper in raw material. Twice the heat tolerance. Half the heat shield mass.
Musk, looking back:
"In retrospect, we should have started with steel in the beginning. It was dumb not to do steel."
What "obvious" material in your work is silently costing you the project?
If you're new here, @GeniusGTX is a gallery for the greatest minds in economics, psychology, and history. Follow along for more similar content.
P.S.
I've made a free playbook on how to use and create your own mental models.
This includes the same thinking strategies Feynman, Munger, and Musk built their careers on.
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— Elon Musk ( @elonmusk ), CEO of Tesla and SpaceX, on Dwarkesh Patel's ( @dwarkesh_sp ) podcast
Dear God, make a way for anyone who says, “Help me, Lord.”
Not just any way, the right one, the healing one, the breakthrough they’ve been waiting for.
If you can…
type “Help me, Lord” and trust that something is shifting.
Richard Feynman's favorite integral trick 🧠
Feynman’s integral trick is a method of evaluating integrals by differentiating them with respect to a parameter that is introduced artificially. The idea is to find a function of two variables, F(x, t), such that the original integral is equal to F(x, 0) for some x. Then, by applying the chain rule, we can obtain a differential equation for F(x, t) and solve it using initial or boundary conditions. The solution will give us the value of the original integral.
• Introduce a parameter t and define a function F(x, t) such that the original integral is equal to F(x, 0) for some x.
• Differentiate F(x, t) with respect to t and obtain a differential equation for F(x, t).
• Solve the differential equation using initial or boundary conditions and find F(x, t) as a function of t.
• Plug in t = 0 and get the value of the original integral as F(x, 0).
In his autobiography Surely You're Joking Mr. Feynman!, he mentions,
I had learned to do integrals by various methods shown in a book that my high school physics teacher Mr. Bader had given me. It showed how to differentiate parameters under the integral sign — it’s a certain operation. It turns out that’s not taught very much in the universities; they don’t emphasize it. But I caught on how to use that method, and I used that one damn tool again and again. If guys at MIT or Princeton had trouble doing a certain integral, then I come along and try differentiating under the integral sign, and often it worked. So I got a great reputation for doing integrals, only because my box of tools was different from everybody else’s, and they had tried all their tools on it before giving the problem to me.
Say this with me:
Dear God,
David stained his hands and Peter broke his word, yet mercy did not resign them from destiny. Father, where I fractured trust through immaturity, please restore and reintroduce me to my assignment.
Where I squandered sacred opportunities through inconsistency, clothe me again with discipline, depth, and the dignity of stewardship.
Baba, na you dey restore fallen kings and recommission trembling apostles and you're also the author of my story.
So please don't let my misjudgment mutate into permanent limitation. Let your mercy interrupt what pride & foolishness almost destroyed.
Thank you sir.
Amen
This is wild! Scientists used liposuction to suck out ordinary white fat cells...then used CRISPR to turn into “beige” fat cells, which voraciously consume calories to make heat.
Then, they implanted them near tumors the way plastic surgeons inject fat from one part of the body to plump up another.
The fat cells scarfed up all the nutrients, starving most of the tumor cells to death.
These cells wiped out breast, colon, pancreatic, and prostate cancers by depleting shared resources.
They even used patient fat from mastectomies to target their own breast cancer.
Why Fat?: Easy to harvest (liposuction), edit, and reimplant safely – biocompatible, no migration risks.
Full article below 👇
They all killed it but guy that sang at the modulation bit made me stand on my feet, because what??? Eargasm
I’ve said this so many times, this song has the greatest bassline ever
As a young boy who came from the streets of Olusosun, who had to hawk in traffic almost every day of the week while growing in-order to survive the numerous challenges my family and I were facing, becoming a Treasure in Africa and World Football was a wild dream. Words can’t express the joy in my heart, this is a very special moment to me.
My football journey has been a rollercoaster of highs, tough lows and emotions. The goals, echoes and jubilation of victories keeps me going even when the critics, hate and pain of defeats hit me hard in the chest. The support of my amazing family, my fans most especially my Nigerian supporters and the love for the beautiful game of football motivates me to aim higher daily.
Losing my dear parents in the course of this journey leaves a scar in my heart as they have always been my major driving force for success since I was a kid, may their souls continue to rest in peace. To my wonderful family thanks for always having my back and loving me so much. I wouldn’t have made it this far without your esteemed support. To my fans and Nigerian supporters, your dedication in supporting me on the good days and bad days do not go unnoticed, even amidst the arrows of hatred thrown at me y’all still stood by my side. I am grateful.
Winning the CAF Best African Player 2023 is a testament of my hardwork, your love and support. I am so proud of myself for achieving this prestigious award. Thank you CAF, to all the coaches I have played under both local and international, your wisdom and knowledge have played huge roles in guiding my footballing career, thank you so much. I am sure my parents in heaven are smiling at me, this is for you. I also congratulate Chiamaka Nnadozie and Asisat Oshoala for their prestigious awards. Dreams do come true! Thank you everyone,GOD is the greatest🙏🏽❤️🇳🇬
There is something skilled workers from Togo and Benin Republic are doing that their Nigerian counterparts are not doing, and that is real training and paying attention to details.
When you look at their work and the finishing, the difference is always clear. The edges are straight, smooth and neat.
Nigerian bricklayers, tilers, POP guys, painters, etc, are losing jobs to them.
In 5 days our Theology on Twitter Initiative will kick off.
These are the lessons that will be taught:
Basics of Systematic Theology
Theology Proper(Study of God)
Theological Anthropology
Harmatiology
Christology (Pt. 1)
Christology (pt. 2)
Pneumatology
Soteriology
Ecclesiology
Eschatology
What is remarkable about this is the order in which you will learn the topics.
It is in the right order of spiritual knowledge about God.
There will be a day break between each lesson so you can have enough time to reflect on the learning.
After the end of each lesson, we will make a short explainer video to summarise it all.
Again, get a notepad and pen dedicated to this.
Each module in a lesson will be released at 2hr intervals throughout the day.
E.g.
Module 1 of Christology by 9 am
Module 2 by 11am
Module 3 by 1 pm
Module 4 by 3pm
Please turn on post notifications. Focus on the lessons.
There will be a general assessment at the end of the course.
A 70% score would be needed to get a certificate.
We are excited to go on this spiritual journey with you. See you in class in five days!
Please retweet!
A Pastor in kaduna state charges church members N310,000 each to fly them to heaven 🤦🏽♀️🤦🏽♀️🤦🏽♀️took them to Ekiti state, says it's the takeoff point🤷🏽♀️
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