« October 15, 2021 | Main | October 17, 2021 »

October 16, 2021 Archives

Saturday, October 16, 2021

THE HAPPENING WORLD: Rwanda Files to Operate 327,320 Satellite Constellation

Satellite Network Filing RRW2021-42537 was received on 2021-09-21 for the “CINNAMON-937” constellation, which is described in the supplementary notes [PDF] as:

An orbital shell is here defined as the set of orbits with the same inclination. There are 27 of such orbital shells. Each orbital shell, except the equatorial shell made of one single plane, has a total of 12,960 satellites. The 27 orbital shells comprise of 327,320 satellites.

Satellites are to orbit at altitudes between 550 and 643.6 km in shells arranged by inclination,

Posted at 13:49 Permalink

CONTINUITY: The Sound of Sorting: Fifteen Algorithms in Six Minutes

Sorting items into order is an important task in computing, and a great deal of intellectual effort has been put into studying various techniques optimised for different circumstances. For example, sorting a small collection of objects that fit into memory is one thing, while a huge database that spans multiple removable storage media is entirely another. An algorithm that works well for data that's initially in completely random order may not be the best for data which is mostly already sorted. Donald Knuth wrote an 800 page book on Sorting and Searching, and new work on the topic is published every year.

This video visualises the behaviour of fifteen different sorting algorithms, ranging from very good to horrific (“bogosort”), each operating on a set of random integers with a size adapted to the efficiency of the algorithm. Here is background on how the video was made. A YouTube playlist of additional sorting algorithms is available.

Posted at 13:19 Permalink

THE HAPPENING WORLD: Top Ten Assets by Market Capitalisation


The Infinite Market Cap Web site ranks more than 13,000 assets by market capitalisation, which is defined for various assets as follows.

One can quibble with these definitions: for example, silver, ranked as the 7th largest asset, is an industrial metal which is consumed in many of its applications, so there is a large gap between the total amount mined over history and the existing above-ground supply. For cryptocurrencies, estimates are based upon circulating supply in public hands, excluding funds believed to be lost, some of which might reappear in the future. Obviously, all of these asset prices are volatile and this ranking represents their valuation as of the date of this post.

A few observations: it is stunning to observe that, among companies in the top ten, only Saudi Aramco is not a technology company, and is the only one founded prior to 1975. We often think of Big Oil and Big Banking as archetypes of corporate wealth and power, but only one oil company and no bank made the top ten. The highest ranked bank, JPMorgan Chase, came in at 16th, just before the Ethereum cryptocurrency at 17th. The largest traditional industrial company (but with a strong presence in technology as well) was Samsung at 22, and brick and mortar retailing leader Walmart ranked 23.

The total valuation of the top ten assets combined was US$ 25.7 trillion, which is less than the U.S. national debt of US$ 28 trillion and change.

Autodesk ranks number 306, with market cap US$ 64 billion, beating out Northrop Grumman at 307 and US$ 63.3 billion and Ford Motor Company in 312th place at US$ 62.7 billion. Also in the cheap seats are Federal Express (322), UBS (324), General Dynamics (341), and Honda (381).

Dogecoin is hanging in there at 705th with market cap US$ 31.5 billion.

Posted at 12:15 Permalink

CONTEXT: A Zoologist Contemplates Alien Life

Might convergent evolution and the limited number of biomechanical solutions to the needs of life result in alien life being no more weird than what we find on Earth? (Although if you look at some of the critters that inhabit the ocean, that's already pretty weird.) Dr Kershenbaum's book is The Zoologist's Guide to the Galaxy.

Posted at 11:14 Permalink