Ciro Santilli @cirosantilli 40

This section is about ways in which you can represent a tree.

Trees are a specific type of graph, so any graph representation also provides a way to represent a tree.

Therefore this section will focus only on methods specific to tress, and which cannot be used for graphs in general.

A really good option to store educational media such as images and video!

Shame that like the rest of Wikimedia, their interface is so clunky and lacking obvious features.

Gun-type fission weapons are the simplest approach and they work with Uranium-235 bombs as you can ignite it with just one explosion.

But Gun-type fission weapons don't work with plutonium, and weapon grade Plutonium is cheaper than weapon grade Uranium, so it wasn't much used.

The cool thing about parallel evolution is that it shows how complex phenotype can evolve from very different initial genetic conditions, highlighting the great power of evolution.

We list some cool ones at: polyphyly.

The only isotope found on Earth because it occurs as part of the uranium 238 decay chain, i.e., it is not a primordial nuclide.

Interestingly it is a bit less stable than other isotopesL such as Polonium-208 (3 y) and Polonium-209 (124 y), but those aren't in any Earthly radioactive chain so they don't show up on Earth.

Plutonium-based.

Its plutonium was produced at Hanford site.

Used in:

2022: saddle and seat post stolen near home. Burn in Hell, motherfuckers. Bought a seatpost marked SP342 MICROPOST ALLOY 3 30.4mm. Like this: web.archive.org/web/20220208115055/https://www.ebay.co.uk/itm/Lightweight-Alloy-Micropost-Bike-MTB-Seatpost-25-4mm-Seat-Pin-300m-Long-Silver-/402311713393 but 30.4mm. OK, bought the Park Tool PW-5 15mm pedal wrench tool. Wasn't expensive at all.

TODO understand other markings on receipt: "18 Flourish FS W Sil XS".

The exact specs pages is lost forever. Closest one we've got is the 2020: web.archive.org/web/20200927204537/https://www.liv-cycling.com/gb/flourish-2

Frame: size: XS. Marking near bottom bracket: F/N GY17Z1327 DK: WGI GY17Z1327 F ES:BI-2339.

Seatpost: TODO diameter. Measured in store 30.4mm after original stolen, although 2020 says 30.9. 30.4mm seemed to fit OK, and measuring with ruler gives 30.5/30.6, I don't think a 30.9 can possibly fit.

Saddle: Liv Contact Comfort Plus Saddle, color golden brown. Same as this but blown: www.liv-cycling.com/gb/contact-comfort-plus-saddle-liv Actual color:

As of 2020, Ciro Santilli is getting excited about quantum computing, which is a deep tech field.

He's a bit lazy to explain why here, but Googling will be more than enough.

There is a risk it will fizzle and the bubble pop, like any revolution.

But recent developments are making it too exciting to ignore.

Discovered by Marie Curie when she noticed that there was some yet unknown more radioactive element in their raw samples, after uranium and polonium, which she published 6 months prior, had already been separated. Published on December 1989 as: Section "Sur une nouvelle substance fortement radio-active, contenue dans la pechblende".

The uranium 238 decay chain is the main source of naturally occurring radium.

Group of all permutations.

Variable resistance element.

Sometimes you get annoyed to death with your bike not breaking or changing gears perfectly as you would like, and the people at the bike shop never do the job well enough.

The problem with bike shops is that the employees are already swamped with work, and they don't get paid any extra for doing more work.

As a result, paradoxically, they are often happier, and respect you more if you are trying to get them to help you to fix your own bike!

Also, for the same reason, they don't have the time to go for a quick test ride after a fix to ensure that the bug was actually fixed.

So they ignore things that would obviously be huge ridability benefits (although they might not be obvious to newbie customers), for which customers would gladly pay more money for.

But you start to learn how to do stuff yourself and it feel amazing when you finally get there (after infinite trial and error).

Ciro dreams of a bike shop that actually calls you for the appointment and then teaches you how to fix the thing.

So the best strategy is to have a backup bicycle, and when your main one breaks, you just try to to the fix yourself. That means:

Then, if you fail to do the fix, that is OK, just take it to the bike shop, with the piece you've bought, and ask them to do it for you. At least this way you did not waste a golden opportunity to learn!

The Nobel Prize of computer software or hardware!

More like a "lifetime achievement" though, rather than the Nobel Prize, which tends to be for more specific achievements.

The dominating model of a computer.

The model is extremely simple, but has been proven to be able to solve all the problems that any reasonable computer model can solve, thus its adoption as the "default model".

The smallest known Turing machine that cannot be proven to halt or not as of 2019 is 7,918-states: www.scottaaronson.com/blog/?p=2725. Shtetl-Optimized by Scott Aaronson is just the best website.

A bunch of non-reasonable-looking computers have also been proven to be Turing complete for fun, e.g. Magic: The Gathering.