I thought it might be fun to make a little game out of asking Fermi problems and trying to work out solutions to others'.

What is a Fermi problem?

A Fermi problem is (to quote wikipedia ):

an estimation problem designed to teach dimensional analysis or approximation, and such a problem is usually a back-of-the-envelope calculation. The estimation technique is named after physicist Enrico Fermi as he was known for his ability to make good approximate calculations with little or no actual data. Fermi problems typically involve making justified guesses about quantities and their variance or lower and upper bounds.

Basically, these are questions that would be very difficult to calculate exactly without looking up the answer. The goal is to arrive at a good estimate by making justified assumptions. As such, looking up facts and statistics should be minimized or outright avoided (e.g., if the question is "What is the mass of the water in Lake Michigan?", you shouldn't look up Lake Michigan's volume to aid your answer. This should be estimated from things you know off the top of your head).

The way this thread works

1. If you have a Fermi problem, post it as a top level comment.
2. If you have a solution to an already posted Fermi problem, post it as a reply to that comment. Be sure to post your reasoning and thought process.

Fermi problems can be fun to come up with, and fun to answer. Examples of Fermi problems might include:

• How many piano tuners are there in Chicago? (this one is apparently one that Fermi came up with himself)

• How many keystrokes occur worldwide, daily?

• What is the mass of the water in Lake Michigan?

• How many cars are there in New York City on a given day?

• How many blades of grass are there on the National Mall?

• How many eggs are consumed in the US each day?

Since many of these have no definitive answer, it is not always possible to score the 'correctness' of an answer. Nonetheless, others can judge when an answer makes reasonable assumptions, so feel free reply to answers with suggestions of which assumptions can be refined or further justified.

I have had a varied work history for the last decade but it has all been W-2. I now find myself doing consulting engagements and I am wondering if I should setup an LLC for this work. My main concern is actually limiting liability, and of course I am interested in possible tax advantages.

Has anyone else done this? If so, what’s the best way to set this up? Stripe has a program, I imagine legalzoom does as well..

Here's the background story about the video: #GenerationLockdown: Two Australians shake up America with viral anti-gun ad

And here's the video itself: Generation Lockdown (The video is not graphic in any way. It's safe for work. Whether it's safe for your emotions is a different matter.)

Right now there's a little doodle for the reddit logo to congratulate UVA on winning the NCAA tournament last night and it really brought me back to the days when this was common. Fun times. Of course you can't see it from the redesign, fittingly.

You can see a catalog of every one there's been at r/logo.

A while back I saw a cool link on Tildes, I think it was before the save feature was implemented, which is why I've lost it. It was an article with an accompanying JavaScript toy to demonstrate the point: if a system starts clustered, equality alone won't bring the system to equilibrium because the system has momentum. You have to swing hard in the other direction to get to actual equilibrium. (i.e. it was a defense of affirmative action.)

Basically, you set some conditions meant to represent demographics. The people were represented by little squares in the simulation. The conditions were things like "start X% concentrated" and "squares must have 2/3/4 different colored neighbor squares."

I think it was on Medium, but I'm not sure, and I can't for the life of me find it again even after scouring Tildes, Reddit, and Google. Anyone know what I'm talking about and where I can find it again?

Personally, I strongly dislike it. Every aspect of every film is way overblown there.

If there's a funny scene in a movie, they LITERALLY die laughing and wake their whole neighbourhood up.

If there's a scene that is in the slightest bit sad, they're going to cry their eyes out for months.

If there's a movie that's decently good, then it's an absolute masterpiece and the best movie of the decade.

And so on... Everything is always really exaggerated.

On top of that, there's always the circlejerk hivemind aspect. Threads are closed after 6 months, so the whole discussion about the film is divided between many threads, but because every thread is small and new, you often get the same fluff comments.

For more popular flims, it is the absolute worst. With half the thread being just funny quotes from the movie with no additional commentary or anything valuable, yet having thousands upon thousands of upvotes. It's kind of sad.

I used to go to IMDb boards, –which, admittedly, had their own issues– but they were still pretty useful for discussion. And shutting people up wasn't as easy as it is on Reddit, so the opinions there were much more varied. However, since they shut them down, Reddit is the closest thing I've found. Moviechat.org is supposed to be a replacement to the IMDb boards, but it's pretty inactive.

So, even though I kind of despise r/movies, I'm sort of forced to use them. But reading it makes me somewhat bitter.

What about you?