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peterwoerneron Ask HN: Where do you find potential customers to validate your idea / MVP?

I have just started trying to cold email/linked in message people who have the relevant job titles on linked in. I just started yesterday so I can't tell you how its going yet. But I'm looking for people at companies large enough to have people dedicated to a specific subsets of mechanical engineering.

peterwoerneron What I learnt after burning $10M as an entrepreneur

I think its just the nature of innovation. It takes 1/4 the effort to copy as to create new and this is true in marketing as well as engineering. Call it the second mover advantage, where someone else has already paid the cost of innovation, risk reduction and marketing (convincing people that they want x) and the second mover capitalizes on the new zeitgeist that they created but with lower overhead.

peterwoerneron Man Built a $188M Fortune Investing in Stocks Then Donated It to Charity

I don't want to be too combative because you do have a point that, especially with kids, its hard to not live paycheck to paycheck. But if you start early all you have to do is bust your butt and live cheaply for a couple of years and wait for compound returns to kick in.

Back of the hand says that if you invest 10,000/yr from 20 to 30 you'll have saved ~$100,000. And then 7% and with the rule of 72 is then: 30: 100,000 40: 200,000 50: 400,000 60: 800,000 70: 1,600,000.

S&P is closer to 12% than 7% which means you might be able to get away with saving less aggressively or earlier retirement. If you are able bodied and willing to learn a trade you should be able to make atleast 20/hr. I made 19/hr right out of college as a manufacturing technician and saved ~1000 month. You have to sacrifice to do this e.g. live with roommates in a cheap area, rarely go out to drink/eat etc., but if you start early, don't have kids and save aggressively its very doable. I didn't completely live like a monk, I bought a canoe and went canoeing most weekends and had a rock gym membership for one year while doing this and a martial arts membership the other year. I also lived one block from the projects in a 3-1 with 3 other people so rent was tiny and ate rice and beans + chicken thighs or eggs 3-4 times a week for dinner to keep the cost of food down. Its straight forward on median salary, but you have to sacrifice. The budget is straight forward too: The budget is simple, you get 400 for rent, 400 for food, 400 for transportation, 400 for bills (internet, electric, water, sewage), 200 for health care expenses, 100 float and 100 for fun. You can even do it in SF if you do two people to a room (just like dorms in college) in a large house--transportation will goes down, rent might go up and food probably goes up as well.

You could also work 50 hours a week and save that extra 25% of salary which again at entry level in the trades would yield you close to 10,000/year (minus taxes but hello IRA). The Dave Ramsey retirement calculator says that if you save 1500/month from 22-25 you with 10% returns and no savings after that you'll become a millionaire at about age 53. You can make that happen as an entry level mechanic who lives like I did who works an average 10 hours of overtime a week.

peterwoerneron Man Built a $188M Fortune Investing in Stocks Then Donated It to Charity

If you had a million you could also get a loan with interest less than "risk free" assets. E.g. The stock market makes 7-10% but you can get a loan for 1-3%. So 1.5x your returns then become 12-16%.

Perhaps you can invest in lower risk dividend stocks which will pay out your interest + a little and 3x. If we assume those stocks only make 4% but also pay out 3% then you are looking at 16% returns. Moreover when those dividends get raised you are doing even better.

Leverage can go a long way if used well.

peterwoerneron Man Built a $188M Fortune Investing in Stocks Then Donated It to Charity

Not $188 million rich, but certainly $2-5 million rich.

peterwoerneron Mindsets to Avoid as a Senior Software Developer

And the junior will learn which things to learn. I certainly think you should allow juniors to code review senior coders work if for nothing more than mentoring, but I am sensitive as to why an overloaded senior would balk at the idea.

peterwoerneron What’s Wrong with “Multiplication Is Repeated Addition”? (2008)

Yep and how to construct, the naturals from set theory, the integers from the naturals, the rationals from the integers and the reals from the rational. I've forgotten the details at this point, but I remember the conclusions.

peterwoerneron What’s Wrong with “Multiplication Is Repeated Addition”? (2008)

But you can define multiplication based on abstracting repeated addition. That how we did it my analysis class, although I forget some of the details. So if you say multiplication is repeated addition, it really isn't a lie.

peterwoerneron Mindsets to Avoid as a Senior Software Developer

I think the issue is that many of us are poor communicators (myself being number 1) so we say nothing I can do will help you instead of I can't teach linear algebra, numerical analysis and do the code review in an hour. Therefore putting a junior engineer who has a weak math background on a code review for my new algorithm which uses spectral sparsification for approximating matrix inverses in n log(n) isn't a good idea.

peterwoerneron Facebook’s ad campaign shows how worried it is about Apple's privacy changes

You assume that Apple is telling the truth. The cynic in me thinks that they narrowed the definition of tracking and follow in a legal sense but not in the way we would think of it. Or they are outright lying. It is also possible that it isn't apple doing it but a third party doing it on Apples behalf.

peterwoerneron Medical chatbot using OpenAI’s GPT-3 told a fake patient to kill themselves

I would saw that copy.ai is a low but not zero stakes application. It develops a draft of copy for ads, landing pages etc. which you can review before taking live.

peterwoerneron Scientists begin building highly accurate digital twin of our planet

I am familiar with it in the aerospace industry. Digital Twin implies a higher degree of fidelity in terms of importing data from sensors and modeling of physics than just model or simulation might apply, even though it is a model and simulation.

For GE's digital twins in the jet engines, they will build a high fidelity representation of the each individual engine based on as built parts, and then they will simulate every flight based on accelerometers, force sensors, humidity sensors, temperature and pressure sensors which they have placed in the engine. This is different from a general model or simulation which will build a model from CAD and then have a series of expected flight simulations and use that to predict life of the engine.

peterwoerneron Show HN: Can’t afford Bloomberg Terminal? No prob, I built the next best thing

Awesome, thanks for the tip.

peterwoerneron The U.S. Air Force just admitted the F-35 stealth fighter has failed

They also cap profits based on the original bid size. So you bid 20 million for the F35 program you get 1.5 million profit. When you overrun the 20 million to 30 million you still only get 1.5 million "profit". Typically you also have to go ask for that 10 million in piecemeal as well. I need 500k to do this and 500k to do that and the program office approves or disapproves.

Of course, the contractors probably skim a little bit off the top of the 20 million back to themselves. They might for example bill for machine team on the CNC or charge $200/hr per an employee and only pay $60 (note that they have expenses for training, downtime, office space, equipment and management which that 200/hour needs to account for so the employee isn't getting screwed that badly.

Less moral contractors might build projects which intentionally fail but meet the specifications so that the gov't needs to execute a change order at which point they would get additional fee as part of the change order, however with the DOD you can get your company put on a blacklist which will mean you cannot win any more DOD contracts. But I have heard of a California construction company doing that repeatedly over the course of 30 years successfully. In the dod world, most companies try to propose improvements to the original contract. Typically they will have yearly goals associated with submitting and winning change orders as its an easier source of revenue than bidding and winning new contracts which typically have a 30% win rate.

peterwoerneron Show HN: Can’t afford Bloomberg Terminal? No prob, I built the next best thing

I am making a comment just so I will see the project later. Swamped at work but in a week when I have some free time... I feel like a kid waiting on Christmas with presents under the tree.

peterwoerneron Texas-Style Blackouts Are the Future

There were no major causes it was a systemetic failure across all sectors due to nothing being winterized. Gas failed, coal failed, wind failed, solar failed, the grid failed. Its politics to point only at gas or only at renewables, it was systematic, which might be what you are saying.

peterwoerneron Parched oystermen, farmers face off in Supreme Court water war

A Georgia lawmakers also sued Tennessee to move the state border so that they could siphon water from the Tennessee river: https://www.usatoday.com/story/news/nation/2013/04/01/tennes...

Georgia and Atlanta have unsustainable growth which their natural resources can't support and are trying to pass off the externalities onto their neighbors. I am biased as a former resident of both Tennessee and Florida.

peterwoerneron The Fantasy of Opting Out

Very few people articulate the upside of the data sharing well. And that is the internet allows people to connect with the long tail customers. All of a sudden I can make friends with other worm farmers in the world. Not only that, but using this data I can effectively find other people who would probably be interested in worm farming and tell them about it. And grow the community of worm farmers. Not only that but individuals can now build niche businesses based around worm farming because they can find their potential customers. You can replace worm farming with every esoteric interest.

On one hand the internet and the big data platforms of Amazon, facebook etc. have allowed this economy and communities based on esoteric interests, but on the other hand they are able to manipulate us else like nobodies business and greed ensures that if it isn't being used adversarially now it will certainly be in the future.

peterwoerneron Algorithms by Jeff Erickson

Well the feedback loop is much faster with a solution manual than a professor. I agree there is a line between leveraging the solution manual to teach yourself more quickly and just copying the solution. My quantum mechanics professor would give us the solutions to the homework before we were expected to turn it in so that we could learn from his explanations.

I agree that you have to a some point learn how to approach problems which you haven't seen before, but almost every field I have seen, the right way is to start by copying solutions of others until you understand it and then riffing from there. My father was a professor/researcher and he said you shouldn't start a problem unless you knew what your solution was and what you expected it to provide.

In fact much of the research work I have done is see if technique from field x will apply to field y after I have become an expert in field y. Or push to edge of field y and take the next logical step. But pushing to the edge of field y almost always requires working through the solutions of the people who have been there before rather than reinventing the wheel.

peterwoerneron Algorithms by Jeff Erickson

Is it really cheating. If the goal is to learn the material using someone else's solution is incredibly helpful and can expedite the learning process. If there is a process to master a skill in 20 hours and another way to master it in 5, only the fool would chose the 20 hour process.

When I took electrodynamics the first semester I worked through all the problems myself. I started on Sunday would ask questions Monday and Tuesday where I was stuck and the process took me 20ish hours each week. When I took the second semester, a couple of the other students had the solution manual. I would attempt the problem, then when I got stuck, I would consult the solutions manual, understand what the solution manual was doing, then go back to my work and understand the problem. It would help me track down errors I made in algebra. I ended up spending about 10 hours a week on the problem sets, understood the material better (as well as the material from other classes) and got better grades (on both tests without solutions and homework).

I used to tutor kids in physics and one of my students went from a C at midterm to an A because there was real time feedback for the homework he is trying to do so he was able to grok the material. Worked out solutions to the homework problems is the next best thing.

When I was teaching myself machine learning, it was the same deal, I started working through other peoples worked out problems, it helped me grow my programming skills and learn machine learning more effectively. I would take their code break it down, add comments to lines I didn't understand on first reading and ran the programs.

Learning from solutions is one of the best ways to learn. And it is stupid to have to do twice as much work for the homework problems because some kids might cheat themselves. The alternative for students who have gotten behind or don't know the background is that they don't learn the material because you don't have . The solutions manual gives them an opportunity to catch up.

peterwoerneron The Irony in the GameStop Story

https://twitter.com/PigeonsK/status/1354824493982773249

Argument for cascading.

peterwoerneron Amazon: Not OK – Why we had to change Elastic licensing

Right now it is better for the customers, but that doesn't mean it will continue to be this. You assume that once/if Bezos crushes the rest of the competitors he won't start significantly increasing prices.

We saw something similar in the 90s where health care prices plummeted as the now winners developed and convinced the public that their monopolies were good. Now they are able increase prices by 15-20%/yr into the foreseeable future.

This is not a prediction (per se), but a statement that we should realize that monopolistic might be good for the consumer in the short term but bad in the long term.

peterwoerneron Jobless, Selling Nudes Online and Still Struggling

One of the traps of minimum wage jobs is that they take up so much energy and time that it makes it difficult to go do things which improve your life (especially if you have a young family). Additionally, many give you unpredictable, inflexible and difficult hours which furthers the difficulty of improving your situation.

peterwoerneron Games people play with cash flow

There is an important point about reasoning here which is worth stating explicitly. You can reason perfectly about the things you have thought of and know, but they things you didn't think of and don't know might still change the correct answer.

peterwoerneron Is Probability Real?

I don't remember, the thing which really helped me click at least the bayesian interpretation was if we have A --> B and B, then A is more plausible and probability reasoning is a way to quantify how more plausible A is now that we know B is true.

Chapter 5 is also a doozy in terms of explaining some of the things going on currently.

peterwoerneron Is Probability Real?

Check out the first chapter of Jayne's probability theory. It's the clearest take down of the frequentist interpretations that you have and introduction to the Bayesian interpretation.

http://www.med.mcgill.ca/epidemiology/hanley/bios601/Gaussia...

peterwoerneron Microsoft 365 has employee surveillance and analytics built in

Asking which of the fifteen memos they read this past quarter might not be a great use of time when you only have ~30 minutes for the one on one.

peterwoerneron Victoria follows South Australia and imposes electric car road tax

Most public schools I have been a part of charge "optional" fees. There seems to be constant fund-raising for both extracurricular activities and general school funds as well as requests from students for classroom supplies. The bulk of the funding comes from the school taxes.

peterwoerneron Victoria follows South Australia and imposes electric car road tax

As someone who migrated to upstate new york from Florida, I disagree. People here are constantly repaving, repairing, and resurfacing their driveways and sidewalks. While you need an initialization crack, that can come from a host of issues other than heavy vehicles including thermal cycling and initial defects. I will note that the asphalt and concrete construction may be different in the south vs. the north, but there is much much more driveway repair up here than there was in Florida.

As a pedantic side note, this is why your batteries die, the copper leads begins to fatigue and fracture due to stresses from thermal cycling.

peterwoerneron Arecibo telescope, on the brink of collapse, will be dismantled

Roman Space Telescope, LISA.

[1] https://roman.gsfc.nasa.gov/

[2] https://lisa.nasa.gov/ , https://www.esa.int/Science_Exploration/Space_Science/LISA