How to Run a Blockchain on a Deserted Island with Pen and Paper - <AUTHOR> https://hackernoon.com/how-to-run-a-blockchain-on-a-deserted-island-with-pen-and-paper-899949ec555b <comment><USER2> _What are we trying to achieve? It's very simple actually — all we're trying to do is maintain a simple table of balances on a piece of paper. This table will show how many coins each of our heroes has. The trick is, because we can't have one piece of paper that holds the only source of truth — we're going to have to keep things equal and let each of the gang maintain their own version — this is the decentralized part. And naturally, we're also going to hope that all 4 pieces of paper eventually show the same thing — this is the consensus part._

Nothing in the statement of the problem requires a block chain.

Maintaining distributed ledgers is not a difficult problem except for one niggling detail: _double spending._ In other words, if the scenario you're looking at has no risk of double spending, a block chain isn't going to help you at all.

To expand on the article's example...

Jack is down to his last coin and gets a brilliant idea. He'll pay Kate and Hugo each one coin during the day. If he succeeds, Jack can forge one coin out of thin air.

The islanders face a dilemma. Which of Jack's two payments should be accepted? Accepting the payment to Kate means that Hugo loses his. Accepting the payment to Hugo means that Kate loses hers.

Accepting both payments is a non-starter. The islanders may as well just start bartering again if monetary scarcity can't be preserved.

This is the motivating example behind block chains. The system we know as Bitcoin had been largely worked out by the time Satoshi released the white paper in 2008. Digital signatures and hash chains mean that forgery of coins or payments is practically impossible.

What was missing was a way to make double spending difficult, without invoking a central authority.

<comment><USER3> Excellent reply. One could expect HN to be less susceptible to this fad that is blockchain.

To be fair, the author never said it was the only or best solution, but articles similar to this could make use of a note mentioning that there is no need for blockchain and there are more efficient ways to do this.

<comment><USER4> HN is susceptible for two simple reasons: money and ideology. Many here have stakes in cryptocurrency and until they can find new bag holders they need enthusiasm. In this space enthusiasm and popularity are directly translated to profits. The second is that there is a small yet vocal minority of cryptolibertarians, you know ones who think "fiat is dead!" who desperately want cryptocurrency to not only thrive, but triumph.

</comment></comment></comment><comment><USER5> The consensus here is trivial to control by the strongest of the group. What if when Hugo sent the 200 coins, he said "oh we're allowed to generate 200 coins if it has been over 3 days of no coin generation" and his statement would be impossible to verify because:

1- They have no way to get in touch with the central authority, the developer (author of the blog post), who can tell the users if the new consensus rule is allowed or not.

2- They have no written account of the consensus rules, which would help to at least invalidate new consensus rules that seem to conflict with the written ones.

So what would happen if Hugo did this? Well if he's the strongest of the bunch, he could simply impose on the group and say "this is a new consensus rule, accept it or else". So much for decentralized consensus!

<comment><USER6> > _Well if he's the strongest of the bunch, he could simply impose on the > group and say "this is a new consensus rule, accept it or else". So much for > decentralized consensus!_

Isn't this _always_ the case? If Hugo is strong enough, he can also bully his way into abandoning the blockhain, and relying on his word for what everyone's balance is.

(Of course, this kills any notion of an actual economy, and becomes a totalitarian regime powered by effectively slave labor...)

<comment><USER5> > Isn't this _always_ the case?

Well yea, that's how societies work. Social hierarchies emerge as we delegate power to the strong and wise. If they abuse their power, there is strife and potentially war, and eventually the corrupt leader gets replaced with a new one.

The idea that Bitcoin or any given blockchain is "more decentralized" than what we currently have is profoundly flawed. All you have to do to control a blockchain is control its consensus rules, as the Hugo example demonstrates. All you have to do to control the consensus rules is control the developers... and developers don't operate in some parallel universe outside of our governments' control.

All that to say, yes indeed, Hugo runs the show here, blockchain or not... just like he runs the show in the real world.

</comment></comment></comment><comment><USER7> This is great. Planet Money mentioned how it was/could be used in prison: [https://www.npr.org/sections/money/2017/02/10/514577243/epis...](https://www.npr.org/sections/money/2017/02/10/514577243/episode-753-blockchain- gang)

</comment><comment><USER8> Inefficient, mostly not new either because in the past you'd have one person with that responsibility: the one who has experience with ledger. Now everyone's a notary. How it'd happen with centralized/specialization is another person would cut wood, yet another would hunt fish, and everyone would do their part (you can see this in effect in the movie The Beach [1] though the group is larger than 4 like in this example; also in Cast Away its just that there's only 1 person there who has to do everything by himself which makes it a redundant example). Everyone specializes in something because that is more efficient when HR are scarce. Because the group is small its easy to keep track who's doing what; instead of pet peeves like ledger.

So in short either you're so _bored_ that you don't have anything better to do, or you're _busy_ with surviving. If you're bored and you happen to have pen and paper I can recommend something different: PnP RPG. Such relies on something you'll always have with you even when you're alone (see Cast Away [2] as well): your imagination.

[1] [https://www.imdb.com/title/tt0163978/](https://www.imdb.com/title/tt0163978/)

[2] [https://www.imdb.com/title/tt0162222/](https://www.imdb.com/title/tt0162222/)

</comment><comment><USER9> For anyone interested, there is literally no evidence that any society anywhere, ever, switched to using money because using barter was so onerous. [0] On an island like this one the inhabitants would inevitably create a system based on mutual aid and ongoing negotiation of responsibilities to one another. While this is a fun article, to me it exposes how cryptocurrencies are primarily useful as a value store and a means of speculation rather than a solution to actual human-scale problems.

[0] From "Debt: The First 5000 Years," by David Graeber [https://www.mhpbooks.com/books/debt/](https://www.mhpbooks.com/books/debt/)

</comment><comment><USER10> Love it. Added the IslandCoin White Paper [1] to the Bits & Press Bookshelf (along with the Bitcoin and Ethereum White Paper).

[1] [https://github.com/bitsblocks/islandcoin- whitepaper](https://github.com/bitsblocks/islandcoin-whitepaper)

</comment><comment><USER11> SpaldingCoin is the hottest ICO in the archipelago

</comment><comment><USER12> If there are four of you on a tiny island and you're not running an informally communist society, something's wrong.

Possibly what's wrong is that one of you is a libertarian.

I'm no purely being flippant here - four people are going to be so inter- reliant and form such a small, tigh-knit group, that keeping track of balances and debts is likely to cause more problems than it could possibly solve.

This is a situation for trust, not currency.

<comment><USER6> I agree. You're more like a family at that point than four LLCs.

Then again, I wonder how many people reading that blog post and nodding along are already sketching out a brilliant idea to bring this back home, and have their spouse and kids get on the handwritten blockchain wagon.

</comment></comment><comment><USER13> This is great. We just signed a contract to take ownership of an entire remote tropical island to create an eco hacker space.

I'm inspired for us to implement something based on this as a class.

The island is here > [http://Majagual.org](http://Majagual.org)

Would love to find other cool ideas for projects and inspiration.

<comment><USER14> There is nothing eco about taking over an island to "create [a] hacker space"

<comment><USER13> I appreciate your perspective.

Our first priority is to protect the space and be great stewards of the land. We also believe it is possible for humans to live integrated with nature and for the space to have a positive impact.

Current projects include:

Plastics clean-up and processing. Can the plastics that wash up on shore be used for anything useful?

Working to protect the native plants and animals -- there is currently a pretty sad practice where locals will try to set part of the island on fire to flush out iguanas and then shoot them. They like the pregnant ones the best. This is detrimental to the space as well as the iguanas -- we will work to establish some sort of sustainable relationship so this does not occur.

Development of electric fishing boats that can re-charged via solar.

We have a relationship with the MIT FabLab in Panama City and hope to bring students to the island for immersive experiences as well.

We will be hosting very light leave no trace events as well as building very light eco-infrastructure such as rainwater collection.

Additionally, the space will serve as a platform for inspiration, healing and leadership development. The intention is that by continuing to work with folks in this type of environment they will be exposed to new ways of living and will return with a deeper connection to themselves and nature.

We believe we can work closely with the natural environment and contribute to the increased health of the land and surrounding communities.

We haven't taken outside investment so there is no mandate to generate a financial return. Our plan is to move slowly and with intention. We will also welcome insights from folks like you to help keep us accountable.</comment></comment></comment>


The Scarface of Sex - <AUTHOR> http://www.thedailybeast.com/the-scarface-of-sex <comment><USER2> >'A court heard that he had commissioned a paperweight made from the shattered bones of a second murdered rival'

I was sympathising with him up until that point!</comment>


Watson in the Wild: Brewery Master - <AUTHOR> https://developer.ibm.com/watson/blog/2015/03/05/watson-wild-march-5th-2015/

<comment><USER2> I'm not sure if my expectations were overly optimistic, but using the 'Ask Watson' feature in the beer demo gave REALLY disappointingly inaccurate answers to very simple questions about beer.

e.g. "What is beer made from?" resulted in what appeared to just be a link to a wikipedia article on Brewerys. Not sure if this is implementation issues or representative of the underlying Watson API.

<comment><USER3> The current beer corpus used by Brewery Master only contains a small number of documents. Due to its small size, its very likely the the answer Watson is searching for doesn't exist.

<comment><USER2> Totally see your point, but it makes me wonder why IBM point to this demo as an example of Watson API usage (and how good it is) when the demo doesn't live up to (anything like?) Watson's true potential.

Strikes me as a little counterproductive from a marketing POV.

</comment></comment></comment><comment><USER3> We also have an alternate UI which has a bit more functionality: [http://brewerymaster.mybluemix.net](http://brewerymaster.mybluemix.net)

</comment><comment><USER4> The site doesn't fail gracefully... if it can't populate fields it just keeps the previous entries.

I'm in Minneapolis and if I look at a brewery and then look at Dangerous Man, it can't find the beer list so it just keeps the listing for Harriet or Fulton or whoever I clicked on before. For a spotlight app that is a pretty glaring bug...

</comment><comment><USER5> Three breweries in Denver, and one of them is a BJ's? Watson in the wild indeed.

</comment><comment><USER6> Has there been any pricing information released about the Watson API? I can't seem to find anything but my assumption is that it would not be inexpensive whenever they do start charging for it.

</comment><comment><USER7> Seems like a cool idea, although it doesn't appear to be working (for me) right now.

</comment><comment><USER8> I'm getting fatal JS errors.</comment>


Ask HN: What kind of math do you study in your free time? - <AUTHOR> Currently, I'm working through Gilber Strangs new book "Linear Algebra and Learning from Data" <comment><USER2> Bartosz Milewski's lectures on category theory are great. Also, the accompanying book is well written (and free)!

lectures -> [https://www.youtube.com/user/DrBartosz](https://www.youtube.com/user/DrBartosz)

book -> [https://github.com/hmemcpy/milewski-ctfp- pdf](https://github.com/hmemcpy/milewski-ctfp-pdf)

<comment><USER3> What practical applications does it present for programmers? I've looked at this a bit and it just seems like a regular category theory book.

<comment><USER4> You don't get scared when you read stuff about Haskell because you know what most the fancy words mean

<comment><USER5> On the other hand it would be easier to just avoid Haskell.

</comment></comment></comment></comment><comment><USER6> Some math topics I like to read about / play with:

\- Measure theory / lebesque/daniell integration / stochastic calculus -- super useful but very beautiful. I have a background in mathematical finance.

\- Combinatorial topology -- Simplicial complexes, polytopes. A more finite/computational flavor of algebraic topology.

\- Dynamical systems: Highly interdisciplinary. Brings together physics, fractals, calculus, and computer simulations.

\- Multilinear Algebra -- tensors, grassman algebras.

\- History of Mathematics -- love reading about the development of mathematics throughout the centuries.

<comment><USER7> "History of Mathematics"

Anyone have good book recommendations?

<comment><USER5> Stillwell's _Mathematics and Its History_.

<comment><USER8> Seconding this. His other books are great as well (Reverse Mathematics, Naive Lie Theory). Great writer.

</comment></comment></comment></comment><comment><USER9> Not sure if it counts as "free time" as I study math for a living :) but optimization theory is always on my list.

If you like Strang's new book, I think you'll be quite partial to Boyd's VMLS [0] which is (in my admittedly horrible opinion) even more clear and practical and serves as an incredibly good and basic introduction to both linear algebra and basic optimization (via least squares). It assumes nothing more than pre- calculus level math and some slight familiarity with derivatives.

Honestly, I really, truly highly recommend reading it, even if you're already familiar with linear algebra. It's a joy to flip through the pages and do some of the problems (both theoretical and practical!).

\-----

[0] [http://vmls-book.stanford.edu](http://vmls-book.stanford.edu)

<comment><USER5> > _I study math for a living_

You get paid for _studying_ math?

<comment><USER9> Yes! Well, at least, for the most part.

I am also coincidentally paid whenever I _discover_ math and explain it to an audience, but this case is much rarer than the former.

</comment></comment></comment><comment><USER10> Less focused but enjoyed Eddie Woo's and 3blue1brown's more recent videos on Youtube

Also challenged by Tom Duff's trigonometry page - [http://www.iq0.com/notes/trig.html](http://www.iq0.com/notes/trig.html)

Enjoy learning how to derive identities and equations from first principles - quite like differential of x^2 => 2x and the quadratic eqn via completing the square

</comment><comment><USER11> I'm working my way through Ivan Savov's "No bullshit guide to math & physics" \- [https://www.goodreads.com/book/show/22876442-no-bullshit- gui...](https://www.goodreads.com/book/show/22876442-no-bullshit-guide-to- math-and-physics)

Would recommend it to anyone whose maths needs a bit of a brush up, or anyone who's interested in basic mechanics!

Oh and I'm using Khan Academy for extra practice, which I can warmly recommend as well.

<comment><USER12> Great book, too bad it's got such an offensive title. The book could be used more widely without it.

<comment><USER11> How is it offensive? Because of the word bullshit?

<comment><USER12> Yes. Can you imagine this used in a professional or collegiate setting?

<comment><USER11> Yes, I don't see why not? Maybe this is a cultural thing, but I don't know anyone who would be offended by the word bullshit, professionally or otherwise.

</comment></comment></comment></comment></comment><comment><USER13> I'm working through Oscar Levin's "Discrete Mathematics" \- [http://discrete.openmathbooks.org/dmoi3.html](http://discrete.openmathbooks.org/dmoi3.html)

I studied philosophy in college and am hoping several years of programming experience since will shed some new and interesting light on one of my favorite topics.

</comment><comment><USER14> The predicate calculus. I regularly review Predicate Calculus and Program Semantics[1] to increase my fluency in the techniques. I also recommend A Discipline of Programming[2] as a gentler introduction to the subject for those who do not consider themselves particularly mathematically inclined. For me it was a natural progression from doing TDD. I still code test first, but now the structure of those tests and programs is guided by a better understanding of program semantics, greatly increasing my code quality.

[1] [https://www.amazon.com/Predicate-Calculus-Semantics- Monograp...](https://www.amazon.com/Predicate-Calculus-Semantics-Monographs- Computer/dp/1461279240)

[2] [https://www.amazon.com/Discipline-Programming-Edsger-W- Dijks...](https://www.amazon.com/Discipline-Programming-Edsger-W- Dijkstra/dp/013215871X)

</comment><comment><USER15> There's lectures for that book if you're interested (I don't own the book yet) [https://ocw.mit.edu/courses/mathematics/18-065-matrix- method...](https://ocw.mit.edu/courses/mathematics/18-065-matrix-methods-in- data-analysis-signal-processing-and-machine-learning-spring-2018/)

In my free time I attempt to work through The Nature of Computation by Stephan Mertens & Cristopher Moore. Edit: Forgot to add, there's lectures for the TCS book too in this playlist specifically 'CS Theory Toolkit' [https://www.youtube.com/channel/UCWnu2XymDtORV-- qG2uG5eQ/pla...](https://www.youtube.com/channel/UCWnu2XymDtORV-- qG2uG5eQ/playlists)

<comment><AUTHOR> Nice, thanks!

That sounds interesting. Sadly, I have a huge backlog already...

</comment></comment><comment><USER16> I'm interested in fractional calculus.

It all started with an argument I had with my high school math teacher about whether something like a half derivative is a thing. Turns out fractional calculus is a real thing and shows up in many applied areas of math. The Fractional Calculus by Oldham and Spanier I have lying around treats its applications to diffusion problems, for example. As an EE student fractional PID controller design and fractional signal processing are interesting as well.

For a quick peek into that subject I would recommend watching Dr Peyam's videos on half derivatives[0].

[0]: [https://www.youtube.com/watch?v=eB3OUl5TVSY](https://www.youtube.com/watch?v=eB3OUl5TVSY)

</comment><comment><USER17> I am reading "The Art of Statistics" by David Spiegelhalter.

<comment><USER18> I just finished that. Great book!

</comment></comment><comment><USER19> I'm currently working through books on Linear Algebra (Friedman), Real Analysis (Bloch) and Abstract Algebra (Pinter) with guided help from a math PhD I found via Reddit/Discord. It's going great, and I'm getting feedback on my proofs and learning quite a lot.

I studied physics in undergrad, and am now a math/science teacher, but I feel I missed my true calling in deciding on physics over math; it's just so much more fun, in my opinion. I'd love to maybe eventually do an online math bachelors and then get a masters in it later (or skip the bachelors and get a masters), but all that will depend on if I decide to shift out of teaching or not.

<comment><USER20> Can you please elaborate on how you found a tutor via Reddit/Discord? I would love to study with someone who can help me if I am stuck with a problem.

<comment><USER19> I saw the person advertising on Reddit for his own Discord server in a /r/math thread about learning after graduation, etc., so got quite lucky. I think he still lurks around /r/math and /r/learnmath if you go and ask if anyone can help.

<comment><USER20> Nice! I usually try Crossvalidate SE first. But I'll cross-post to those subreddits as well.

</comment></comment></comment></comment><comment><USER21> Related: do people have good recommendations of "casual" math books for more advanced topics? I.e. ones that an educated reader with a background in math can read through in one pass (unlike most textbooks) but nonetheless have real math in them? (And has fun exercises!)

I can start with some. Feynman's Lectures on Computing. Scott Aaronson's Quantum Computing Since Democritus (though it assumes some background knowledge of quantum computing). I think Colin Adam's "The Knot Book" (on knot theory in topology) as well.

<comment><USER14> Visual Complex Analysis. I'd hesitate to call it casual, but it's extremely accessible to someone with some basic mathematical knowledge.

<comment><USER8> Also, Visual Group Theory.

<comment><USER22> I used Visual Group theory as the basis for some workshops. It's a really good read.

</comment></comment></comment></comment><comment><USER23> The topics that resonate with me the most are graph theory and probability. Incidentally, they are also the most useful for my day job. Graphs are such a beautiful and intuitive concept, it is amazing; basic probability is unbelievably useful for general problem solving, making decisions, modeling the world; both have been written about a lot, yet there is so much more to discover and apply.

Things I'd love to read about if I had more time are: topology (knots are weird interesting things), meta-mathematics (Gödelization and all that, read Gödel, Escher, Bach if you'd like to wet your appetite), paraconsistent logic (how to contain inconsitencies in systems of logic so that they don't become arbitrary - as from contradiction, anything follows). Digesting maths requires a _lot_ of time, wish I could be a student again to sit in whatever lecture that sounds interesting.

As a kid, I loved reading about history of maths; many discovery stories made me become a scientist (applied computer science researcher), and I still enjoy reading about it (also biographies or even mathematically related fiction e.g. The Solitude of Prime Numbers).

</comment><comment><USER24> Been going through Conway's (and Conway related) books since his unfortunate passing. His biography by Siobhan Roberts was a great starting point to ease into it (lots of direct quotes from Conway, which makes it a very easy read that still touches on the important concepts in his work, in his own words; also highly recommend all the Numberphile videos featuring him for that)- then:

 _Winning Ways for your Mathematical Plays_ is really fun to thumb through.

 _The Book of Numbers_ is fantastic and something I would gift to any mathematically curious, somewhat independent, child.

Knuth's _Surreal Numbers_ is also a great read.

Got _On Numbers and Games_ coming in the mail, and am trying to track down a reasonably priced copy of _The Symmetries of Things_.

I'm tempted to get the _Atlas_ for my collection, but I don't think I'd actually get much from reading it (:

In non-Conway recommendations, _The Princeton Companion to Mathematics_ is a huge brick of a volume, but is a very complete math encyclopedia that I love to keep on my desk and thumb through when I feel distracted. You always end up learning something new.

</comment><comment><USER25> I'm a big fan of Schelling's ideas on game theory, and focal points in particular: [https://en.wikipedia.org/wiki/Thomas_Schelling#The_Strategy_...](https://en.wikipedia.org/wiki/Thomas_Schelling#The_Strategy_of_Conflict_\(1960\))

I'd love any further suggestions on complex/multipolar/iterated game theory.

</comment><comment><USER26> For combinatorics, I highly recommend Miklos Bona's A Walk Through Combinatorics[0]. Combinatorics is intuitive and approachable to begin with, and this book is particularly accessible as far as math texts go.

[0] - [https://people.clas.ufl.edu/bona/books/](https://people.clas.ufl.edu/bona/books/)

</comment><comment><USER27> My capsule reviews of what I've read in mathematics over the last 22 years. [http://don.dream-in- color.net/books/archive.php4?iSubject=79](http://don.dream-in- color.net/books/archive.php4?iSubject=79)

</comment><comment><USER28> I always come back to playing with the Exterior (Multilinear) Algebra because it seems like there's some deep structure hiding inside of it that connects a bunch of different fields of math.

</comment><comment><USER29> I'm currently looking at propagator networks [https://github.com/ekmett/propagators](https://github.com/ekmett/propagators)

</comment><comment><USER30> I'd love to raise awareness of [https://www.stat.berkeley.edu/~aldous/Real_World/RW.html](https://www.stat.berkeley.edu/~aldous/Real_World/RW.html) (Probability and the Real World) [https://www.stat.berkeley.edu/~aldous/](https://www.stat.berkeley.edu/~aldous/) Professor David Aldous. This is a wonderful resource. I hope you all enjoy.

</comment><comment><USER31> I tried to learn Galois theory on Coursera a few years ago (the course was in French, which is my mother tongue, but probably few HNers can understand it), and failed the class partly due to lack of time. Since then I've been trying from time to time to read about it, which refreshed knowledge of Group theory, but so far I haven't gotten to the point where I understand Galois's idea to prove that some polynomial equations are not solvable by radicals.

<comment><USER5> You can try this little essay by Stillwell: [http://www.math.jhu.edu/~smahanta/Teaching/Spring10/Stillwel...](http://www.math.jhu.edu/~smahanta/Teaching/Spring10/Stillwell.pdf).

</comment></comment><comment><USER32> I filled a Kindle with just about every paper related to the proof of Fermat's Last Theorem and chip away at it when I can. When I get stuck there, I switch over to trying to understand Ono's closed form solution of the partition function. Both subjects provide hours and hours of diversions into areas of math I never got to learn studying physics.

</comment><comment><USER18> There is loads of great maths stuff on YouTube. For some reason this is my favourite channel: black pen red pen. The author solves unusual algebra or calculus problems. I find it quite relaxing!

[https://www.youtube.com/user/blackpenredpen](https://www.youtube.com/user/blackpenredpen)

<comment><USER33> I find this girl's analysis of Fibonacci series and the Golden Ratio concepts and seeing how it applies to plants to be fascinating:

[https://www.youtube.com/watch?v=ahXIMUkSXX0](https://www.youtube.com/watch?v=ahXIMUkSXX0)

I wish she would edit the video and slow it down a bit (don't like that rapid fire style of tutorial that so many people YouTubers adopt lately) but the presentation is amazing.

</comment></comment><comment><USER34> I'm obsessed with the Mandelbrot Set, so a lot of the mathematics I read recreationally branches from that: fractals, complex numbers, Riemannian and Hermitian manifolds, and related topics.

As a software developer, I explore lots of computer/data-science related topics as well, e.g. cellular automata, dynamics, and some statistics.

</comment><comment><USER35> I failed Linear Algebra in college because I was more interested in partying, it wasn't essential to my degree (Poli Sci), and I incorrectly assumed I could drift through it and get a C like my other hard science requirements. I am currently working through Friedberg's textbook on it.

</comment><comment><USER36> I've enjoyed this series of lectures on Youtube:

"Lectures on Geometrical Anatomy of Theoretical Physics" [0]

[0] [https://www.youtube.com/playlist?list=PLPH7f_7ZlzxTi6kS4vCmv...](https://www.youtube.com/playlist?list=PLPH7f_7ZlzxTi6kS4vCmv4ZKm9u8g5yic)

</comment><comment><USER37> Can someone recommend an accessible book to learn multilinear algebra,tensors with focus on applications

</comment><comment><USER38> Mostly crawling through ml papers on arxiv. Also going over "The Theory That Would Not Die", though this is in the realm of popular science books but it's an enjoyable getaway from it all.

Edit: How to by Randall Munroe for the math-comedy realm.

</comment><comment><USER5> Highly recommended: [https://jeremykun.com/2013/04/03/homology-theory-a- primer/](https://jeremykun.com/2013/04/03/homology-theory-a-primer/)

</comment><comment><USER39> Common Core because my kids are in school. I've heard a lot of parents complain, but I actually love it. I've always had a knack for doing arithmetic in my head and common core is teaching all the stuff I do intuitively.

</comment><comment><USER5> This: [https://arxiv.org/abs/math/0608040v4](https://arxiv.org/abs/math/0608040v4).

</comment><comment><USER40> Orbital mechanics and related mathematics like Stumpff series and Universal variables. Got inspired from playing too much Kerbal Space Program and Orbiter.

<comment><USER41> I've wanted to do this for a while. What's your process like? I have a few books (Introduction to Space Dynamics, the BMW book, etc) but I'm not sure if I should read it cover to cover or try to design a curriculum etc.

Do you use any simulation software or just pen and paper?

<comment><USER40> I started with Bate, Mueller, White: Fundamentals of Astrodynamics, which is US Air force material. It contains two courses, so you should skip some of the chapters at first.

Then I read a bunch of research papers and more in depth literature. Richard Battin's work for example.

I've been hacking on a two body orbital mechanics library in C with SIMD extensions, and an interactive sandbox with OpenGL. I wrote both from scratch.

</comment></comment></comment><comment><USER42> Presently working through Harvard's online Abstract Algebra course and adjunct to that Bartoz's notes on category theory and some type theory.

</comment><comment><USER43> In high school I read Vašek Chvátal - Linear Programming after buying it second hand for a few dollars thinking it was a computer text book.

I liked it at the time.

</comment><comment><USER44> certainly some statistics thoery, when following any MachineLearning core.. (not big on DeepLearning here, all the other ones) Small bits of 'Understanding Machine Learning: From Theory to Algorithms'

Some clustering theory.. some computer vision components, including segmentation methods

Some "data mining" approaches, which are sets and stats, basically..

</comment><comment><USER45> I've always been partial to Galois theory.

</comment><comment><USER46> Sigmoid / logistic and bell curves to try and predict Covid-19 progress.

</comment><comment><USER47> Discrete most recently but I am looking into category theory.

</comment><comment><USER48> I study no kind of math in my free time.

<comment><USER49> Ditto

</comment></comment><comment><USER50> Topology

</comment><comment><USER51> _(Points at username)_

Trigonometry.

</comment><comment><USER52> homotopy type theory!

<comment><USER53> What are you reading/watching? Are there any self-contained material on this topic?

<comment><USER8> Not sure what you mean by self-contained, but there is the Homotopy Type Theory book:

[https://homotopytypetheory.org/book/](https://homotopytypetheory.org/book/)

</comment></comment></comment><comment><USER54> Applied statistics.</comment>


The Ultimate Search Engine (sort Of) for Data Scientists Et Al - <AUTHOR> https://www.lovelydata.cz/tools/search/ <comment><AUTHOR> A simple tool for searching multiple sites from one place. 100% free. Let your inner Data Scientist come out and shine!</comment>


BATTLE: //url.tld VS http://url.tld - <AUTHOR>

Vote for your favorite below. Or upvote if you prefer sharing urls without "http:", and downvote if you prefer keeping "http:" in the picture.
<comment></comment><comment>==
Can we agree to drop the use of "http://www.google.com", and let browsers and email clients auto-generate urls from "//google.com" instead?
Which do you favor for use in print, email and advertising?
Option A (http://)
</comment><comment></comment><comment></comment><comment>
http://google.com
http://facebook.com
http://mint.com
http://news.ycombinator.com
http://voice.google.com
Option B (//)
</comment><comment></comment><comment>-
//google.com
//facebook.com
//mint.com
//news.ycombinator.com
//voice.google.com
Option C ()
</comment><comment>-----
google.com
facebook.com
mint.com
news.ycombinator.com
voice.google.com
Let's see where the community stands. What barriers exist to shortening the syntax for http and https resources to "//url.tld"?
If Hacker News supports the shift, Web 2.0 might just might support the change.
One proposed measure of spectacular success: If Google Mail staff reading this thread devote development time to prefilling the "//google.com" link destination to "http://google.com" when users highlight and link text that reads "//google.com", and promote this as a flexibility feature to its 350 million active users.
(If Google promotes "//link.com" as a secure simplicity feature, we'll save ourselves googols of keystrokes, and enable enhanced textual clarity and reading speed for urls printed in-line in emails and on paper.) </comment><comment><USER2> The question is irrelevant, there is already a standard. Browsers use <http://>, dead-tree material uses nothing, and no one uses //, because that's just weird.

Typing in <http://> is never necessary, so we're already saving as many keystrokes as possible.

<comment><USER3> Delwin, on the keystroke front, adding support for processing the text "//google.com" as a likely link does not impact users like me who type "google.com" into their URL bar.

I'm not proposing that we lengthen "hipmunk.com" into "//hipmunk.com". Just that we shorten "<http://hipmunk.com>, where and when it appears, to "//hipmunk.com", or enable support for such shortening in as many major consumer web applications we can collectively reach, through a top-ranked Hacker News story.

//url is already supported by every major browser.

I don't know how to format or title an HN post to attract attention. I'm starting to regret titling this "BATTLE: //url.tld" instead of something more like, "It's 2012. Why do we still need to write <http://> to tell a web service we've written a link, when // will do?"

Should this not or never reach the front page, if you or anyone you know has an idea of how to get the short //url proposal somewhere it gets considered for a moment by the webdev collective and YC participants (and aspirants), I'd be greatly appreciative.

//news.ycombinator.com (<\- press me, I'm a link)

</comment></comment><comment><AUTHOR> If you're reading a dense paragraph of text,and you come across a google.com link, your eye does not immediately recognize it as a link. But if you're reading a paragraph and you see a //google.com link... well now, that's a link!

Everything that's new and not normalized with a smiling, attractive face beside it gets written up as weird, until it gets normalized and becomes commonplace.

I'm asking HN: Can we collectively make this "//link.com" syntax not weird?

<comment><AUTHOR> And should we?

Do you see merit to supporting all three //news.ycombinator.com, news.ycombinator.com and <http://news.ycombinator.com> on your site as likely hyperlinks?

Consider all the variations of capitalization in the coding community, typified by support for CamelCase, and its variants.

I'm suggesting a mixed-mode url format that distinguishes a url from surrounding text, but without the overhead of <http://>.

</comment></comment><comment><AUTHOR> On Prezi, only <http://> links are translated into links. Screen real estate is precious in a powerpoint presentation. Why can't "//link" get translated into a hyperlink?

</comment><comment><USER4> none of these. I would rather see http:domain.tld or just domain.tld

<comment><USER3> Hmm, that's interesting.</comment></comment>


For Men Who Hate Talking on the Phone, Games Keep Friendships Alive - <AUTHOR> https://kotaku.com/for-men-who-hate-talking-on-the-phone-games-keep-frien-1835277944 <comment><USER2> As for many things, there's a nice Knausgaard quote about this:

> That's what distance does; when the time between conversations gets longer, > intimacy diminishes, the little things connected to one's daily life lose > their place, it seems odd to talk about a shirt you just bought or to > mention you're thinking of leaving the dishes until morning when you haven't > spoken to a person for two weeks or a month, that absence would seem instead > to call for more important topics, and once they begin to determine the > conversation there's no turning back, because then it's two diplomats > exchanging information about their respective realms in a conversation that > needs to be started up from scratch, in a sense, every time, which gradually > becomes tedious, and eventually it's easier not to bother phoning at all, in > which case it's even harder the next time, and then suddenly it's been half > a year of silence.

I'm a guy and I like phone calls to friends, but I let them wander organically with little pressure. Of course, my friends and I have lives where it's not a big deal to set aside an hour or two for meandering conversation, and not everybody does. But wandering conversation is such a high-utility activity for me that I'm happy to do so. At any rate, it beats watching Netflix or whatever by a mile -- I remain confused by how many people say they have no time for friends but also consume a _bunch_ of solo entertainment. I guess if your free time comes in unpredictably scheduled half hour blocks it might simultaneously be hard to plan hangouts and easy to watch TV, but I don't think most people have that kind of life, outside of maybe certain sets of parents of young children?

<comment><USER3> The quote is very interesting but I'd add something. Most of our dreads started after teenagehood, when social bonding was of high importance. Yet it often becomes a diplomatic effort, often void of real emotion. Real is too strong, but it's not vibrant nor fun most of the time. It's smalltalk. And we keep at it because as an adult it's deemed very important, even though, younger, relationships didn't center around mild chat, it was about having fun, cracking jokes, sharing a childish venture, getting something happy about the interaction.

ps: ah well, universe is poking fun at me, a very old friend just sent me a text after many months :)

<comment><USER4> Call them back!

<comment><USER3> I texted right away, with jokes.

</comment></comment></comment></comment><comment><USER5> To maintain relationships as an adult you need regularly scheduled recurring events. Whether its a cookout every other Sunday, a Friday happy hour, Thursday night online gaming, or anything really.

But it must be a recurring event that does not need to be planned each time, but not going is still considered something you are cancelling.

This was common knowledge until we had a generation will cell phones which greatly reduced the amount of informal regularly scheduled events. In large part because coordination is not nearly as difficult so there is less push to just set something up that occurs once every two weeks as opposed to jus doing it last minute via group chat.

<comment><USER6> Or weekly/frequent religious community gatherings.

People who aren't familiar with that might not appreciate the community aspect.

For example, for some flavor of American Catholics, much of a normal Sunday can be blown (as far as the kids are concerned) by dressing up in Sunday best clothes, attending the big folk music mass, the chatter as people spill out of the church and maybe also talk with the priest out back after the procession out, followed by hours of "coffee and donuts" socializing in the parish's school cafeteria or meeting hall.

I'm not that kind of religious, but that's one way to find and maintain friendships, as well as sense of community and mutual support.

<comment><USER7> Can second. I grew up in a Protestant Church like this, and it's a great community. Nice and welcoming people are sometimes rare these days.

I can't help but think that it's just not "cool" to be religious. It's seen as things our parents did, and every one wants to be an edgy atheist. For better or for worse, humans drew community from their churches (or other religious institutions) for a very long time. Churches were uniquely well-suited to "scale" with modern life and urbanization, especially compared to other traditional communities. I'm not saying you have to be any specific religion; I'm guessing many other religions are welcoming as well. But pick something where you can find a community of friendly people _who share your values_ (this is possibly most important).

Edit: I see that the parent comment has now felt compelled to apologize for suggesting that religion could be a good thing. That's pretty sad. Just because you don't believe in God doesn't mean it can't be a helpful thing for others. Quite frankly, I also believe it's helpful for mental health. Believing that when you die you will just disappear is a rather depressing worldview, and I know people with serious health issues who are atheists and are struggling with that. Same with many aging people. On the other hand, being able to "offer something up to God" can be quite cathartic and an excellent way to relive stress.

Priests were the therapists of olden days.

Edit 2: For further clarification, here's my response to those who say "just gather like-minded people". It's much harder to do that without religion. The best definition of religion I ever heard was "an ideology that provides a comprehensive worldview". In other words, something that shapes your perspective on and understanding of every thing else. It is not easy to find such a group of people who share such basic understandings and values without the use of religion.

<comment><USER8> Religion combines two things and some people only want one: opportunity to socialize and build friendships with people who share values; and a belief in supernatural actors.

<comment><USER9> I think the problem with this is that one of those values has to be to consistently attend the meeting. Supernaturalism offers this. Video games rely on consistently being entertained by video games; once it's not fun, you can just leave.

</comment></comment></comment></comment></comment><comment><USER10> I was playing a Moba with my brother almost every day, talking on voice while we played. I had to quit because the Moba was really sucking up all my drive and free time, but after quitting, I really missed talking with my brother. I started playing again for that reason, but had to quit again, because in the year and a half I was playing that game, I really got nothing done other than have lots of fun and piss off my wife. Of course I never call my brother on the phone otherwise, I have no reason to. I have a really hard time finding a middle ground, but the social aspect of gaming is definitely one of the strong positives for me.

<comment><USER11> Why not agree to play once or twice a week? For example, every Monday night, you two jump on for a few hours and play and catch up?

Also, what do you mean you got nothing done? You bonded with your brother. That seems pretty valuable to me!

<comment><USER12> I am not him, but for me "nothing done" in similar situation meant that I did not learned new programming related things despite needing to, did not contributed to household chores as much as I should, deteriorated/neglected relationships with people actually around me and nearby, personal projects did not moved and stuff I was supposed to organize was not organized.

A lot of these games are designed in a way that makes them less fun when played only a little. Or you become a drag on the team. There are also long term quests and you need to be present to participate.

An explocite agreement on playing twice a week breaks "plausible deniality" here. For some reason it is hard to admit that we are doing it for social reasons. It would be like calling brother on the phone directly - the same block preventing you one action prevents the other.

<comment><USER13> _> A lot of these games are designed in a way that makes them less fun when played only a little. Or you become a drag on the team. There are also long term quests and you need to be present to participate._

I think the solution to this is to find games that don't do that

<comment><USER12> I agree, absolutely. Clash royale and other mobile ganes was that solution for me. The problem is when you joined to be with people (brother in this case), but don't want to admit it out loud or that person primary is there for game.

</comment></comment></comment></comment></comment><comment><USER11> Chatting can be difficult for men. As a man, we tend to not make points about chatting about our feelings or life. But, when our goal is video games / bowling / watching a football game / whatever else with downtime, well, the feelings or life conversations aren't our focus then. Loophole! (not to mention sometimes serious conversations can cause awkward silences. Everyone has the activity to turn back to.)

<comment><USER9> It can also be boring and annoying to talk about politics, the weather, or to gossip about people not present. Video games, like sports, offer a very detailed, completely trivial subject to talk about. Additionally, silence while watching or playing a game isn't dead (like silences at the holiday dinner table), it's a steady stream of new conversational material.

</comment></comment><comment><USER14> I made true friends through Ventrilo/TeamSpeak and different games (but mostly Counter-Strike). I've never made a phone call to a friend unless truly necessary but I've spent several hours talking through these.

Nowadays with Discord it's just so much easier and fun for everyone. I'm happy that it was invented and just wish it was open-source but oh well.

<comment><USER15> What is wrong with Mumble? [https://www.mumble.com/](https://www.mumble.com/)

<comment><USER16> My high school/college friends and I (we've been out of school for nearly 15 years at this point) moved to Discord from Mumble. Here were our reasons why:

* persistent text chat - we're spread across different time zones, and the ability to talk separated by time without having to resort to a forum is very nice, pinging someone with a question or with a reminder for our next game and anime night is really nice; having a separate space from group SMS (which we don't really use) is nice because when I'm at work I can log out of Discord and not be bothered, and if I get an SMS I know that it's something that I have to deal with now

* consistent interface across mobile and desktop - it's nice to have a consistent, universal interface across desktop (Mac, Linux, Windows) and mobile (iOS and Android) versions; it's nice that there are multiple apps for Mumble, but that makes support more difficult

* built in screen sharing support - see support note above

* channel permissions - we have subgroups based on interest, listed in an announce channel, and people that want to join in on that discussion can, but people who are uninterested in, say, Warhammer, discussion don't even have that channel cluttering up their interface, nor do they have to explicitly mute it

* push notifications - see ping above, it's nice

* better bot integration - for me, anyway, it's easier to integrate bots into Discord than it is for Mumble - this is subjective

Those are just the reasons I could think of off the top of my head. I would love to be able to self-host our Discord server, and if it had existed at the level of maturity that it is at now, I probably would have suggested moving to Matrix or something similar.

</comment></comment></comment><comment> Funes- >Like others his age, Gill says that his close friendships from high school and college have atrophied, not only because of the distance but because of their mutual aversion to talking on the phone.

I'll take the liberty to illustrate my own experience: my number of friendships and acquaintances has incredibly declined not because of any personal aversion to voicecalls, but to texting and social media.

I've noticed how, gradually, people I'm frequently around have grown more and more reluctant not only to pick up a phone call but also--and more importantly --to engage in face-to-face interaction, something I find absolutely essential to fulfill one's social needs to a deeply satisfying extent. Not having an online, public presence makes you irrelevant to a lot of people. In some countries, for example, not using WhatsApp is plain social suicide.

<comment><USER17> Maybe I am reading this wrong, but I guess I have the opposite experience. With phonecalls I had issues because I have serious tinnitus and have had that since I was young (played in metal bands and was a real man so no earplugs...). Since chatting became normal I made more solid friendships then I ever did in person and definitely then on the phone. I chat like we are sitting together which people find akward at first but then they seem to like it. It is not very different after a while if it is face to face vs writing 1000s of lines of text in some chat client. And the conversations are usually more profound; no noise, no drinking and time to ponder answers and questions.

Face to face I personally still prefer but I notice my younger friends do not and that is fine.

I have been making (and losing them as well; especially the ones I made in my teens: we have nothing at all in common anymore mostly) real friends (as in people that click fast and you talk with day and night if the opportunity is there) over 30 and over 40; those were met online via sideprojects, company buys and sells and some of them I have never met.

<comment><USER18> > no noise, no drinking

I strongly recommend casual wandering walks for anyone without mobility issues as a bar replacement. I don't even remember where I picked up the habit, but I never was really introduced to bars until later, and they always seemed inferior and have shown a few of my friends the benefits of walking around outside and having a chat (sobriety optional).

<comment><USER17> These days, when I meet friends face to face, it is on long walks in nature or the city; we hardly ever sit down. The bar/party thing was referring to what most people around here prefer when meeting 'friends' (close personal acquaintances) so it is hard to break that if people are stuck in that. Especially for people who have fulltime jobs, around here, outside the job you either vacation with the family or are in a bar.

</comment></comment></comment></comment><comment><USER19> Not sure if it is something I picked up from my dad but I hardly chat to friends I have made over the years. As I have grown older I have gotten closer to my family including extended family. When I do meet with my friends we kick off as if we last saw each other yesterday yet sometimes it is a good 5,10 or even 15 years since we last met. The older I get the more memories I seem to have that include my family so I just focus on them. Not to say I don't talk to other people but I make way more effort and it seems much easier to talk to family. Maybe it is an African thing most of us are big on extended family. My uncle is a good 15 years older than me. Growing up he was an adult now we both adults so we can converse on the same level. Same with my dad.

<comment> 52-6F-62 Nah you just described me and my father to an extent. There are variables, but what you described really sounded familiar. And my dad's side is Scottish.

My mom is more social and cognizant if social needs (Irish). Though less so now that they're getting older/retired.

I'm not sure how well it mixes with the norms of Canadian society here. Often feels a touch off-centre but not entirely out of place.

So maybe more a trait of people who just tend toward family over other social connections, and less a heritage thing?

<comment><USER19> Thanks for sharing. Within the extended family different people grow into different roles. You have the aunt who everyone confides in she always tells you as it is whether you want to hear it or not. But since you know it is coming from a place of love its all good. In your 20s you do all the running around. Slaughtering whatever animal needs to be slaughtered. In your 30 and 40s you the ones that make sure things move. You help organise weddings, family meetups, funerals and so on. All these occasions tend to be big back home. Then you transition into a senior role where you act as an advisor to the 30 year olds organising everything. Finally when you are grandmother/father age you just an honoured guest who can do whatever they want :-). You become the joker, family historian ... whatever you want really.

</comment></comment></comment><comment><USER20> Interesting, I've never thought about this but it matches my recent experience.

Friendship as an adult has been about shared interests, not being assigned to the same class or living nearby, so it makes sense.

<comment><USER21> Kids change it too. It's hard not to make friends when you see the same parents a couple times a week at soccer or baseball or swimming, year-after- year. There's a lot of downtime and you around people that you have something in common with.

<comment><USER22> With both of our kids we had a great social life with groups of the other parents all through school. There were annual dances, fetes, mums nights out, dads nights out, meeting for a quick beer etc. etc. Now the kids have left school the majority of that has dropped off, we do keep in good social contact with a couple of people but I really miss how busy and varied the social life used to be.

</comment></comment></comment><comment><USER23> I've seen this with my kids and their school friends when they play online together. They chat and encourage each other, its really sweet and completely different to their off line rough and tumble play. I wake up on the weekends to quiet whispers of "sick play, dude."

<comment><USER24> What ages are your kids / what games do they play (as a father of three i want to encourage the good stuff / discourage the bad)

<comment><USER23> 10 and 7, although the 7 year old plays with the 10 year olds online.

They play minecraft, fortnite, brawlhalla, titanfall 2 ... mostly. They play in the lounge with us watching (I'll youtube while they play) and any game that is a 15, group chat is off.

We are on PS4 so you can turn game chat off and turn friend chat on in the PS4 friend settings.

</comment></comment></comment><comment><USER25> There's a buddy of mine who I stay in touch with by playing Chess on a mobile app. We've had a game going at all times for probably 4 years now with a 3 day time limit on moves.

He's a lot better than me. Overall record is something like 200-50, but it's a simple way to keep in touch.

Other than that, all of my friends of college stay in touch because of college football. We all follow the team, get together at different away games and bowl games. Home games are actually tougher because most people come with a family routine for those.

</comment><comment><USER26> I second this... One of my best friends moved to another country, and we regularly talk on VOIP during console games.

Hell, sometimes we talk for an hour and never even manage to start the game...

</comment><comment><USER27> Having just watched the "Striking Vipers" Black Mirror episode, it was mildly frustrating watching men do everything _but_ talk...

<comment><USER28> I don't know what you mean by frustrating. For a Black Mirror episode, it had such a happy ending!

<comment><USER27> Yeah, maybe I've spent too much time on r/sex and r/relationships. The answer is always communication! It's just surprising to me that someone could be in a relationship for 10+ years and not communicate everything, no matter how embarrassing or intimate.

</comment></comment></comment><comment><USER29> I used to play WoW with a childhood friend on the other side of the country. Unlike MOBAs, I find that WoW is (or at least was during BC and WotLK) are mindless enough that you can actually hold a real conversation.

</comment><comment><USER30> How's the sound quality of these gaming systems?

I hate talking on phones more than ever because rectangular "candybar" smartphones aren't a good fit for a face, and the audio quality is terrible. I have to keep saying "What did you say?"

 _Of course_ I prefer meeting in person, and ideally in a place that isn't pumping in music. It's the only way to hold an actual conversation.

<comment><USER31> Sound quality is perfectly fine. When it's not, it's always because the other party has a crappy microphone or a crappy connection.

<comment><USER18> I just had a chat on mumble last night catching up with a collage friend who now lives back home in the middle east. It was totally fine and clear. I also had a chat with my mother over a cell phone, and she lives in another city in the same state, and that quality was way worse and actually dropped audio at one point. It's really kinda embarrassing how bad phones are at this point, relatively speaking.

</comment></comment></comment><comment><USER32> For me, this is fantasy hockey. I don't even like to watch hockey anymore, but I enjoy the daily interaction with my friends who are no longer in the same city and busy with their own lives.

</comment><comment><USER33> Man I can relate!

I met most of my closest friends in College and we graduated almost a decade ago and have ended up moving to different parts of the states but I keep in contact with most of them via a Discord server and play with some of them on a near daily basis.

It's really great since it feels like we are just hanging out in the dorm hall just shooting the shit.

</comment><comment><USER34> That has been my experience. Friendships are best formed and maintained by working towards some mutual goal or at the very least regular interaction. In the absence of physical proximity games are pretty much the only recreational option.

</comment><comment><USER35> It's funny how s05e01 of Black Mirror addressesthis. [https://en.wikipedia.org/wiki/Striking_Vipers](https://en.wikipedia.org/wiki/Striking_Vipers)

<comment><USER36> That's probably a why the article was written.

</comment></comment><comment><USER37> And it really works. I can chat with my friends, talk during the game, but I'll never talk on the phone. Idk why, but it's nice to know that this is just not my way.

</comment><comment><USER38> Why hasn't this caught on for watching TV together, online ?

<comment><USER39> It's socially unacceptable to talk over a movie or TV show, but welcomed when talking over videogames.

<comment><USER40> This probably has something to do with a movie/TV show is a ready-made story you mentally dive into while a multiplayer game session is a story that you create together. In the first case talking is disrupting while in the second it's _part_ of the story.</comment></comment></comment>


Jerry Brown strips cell phones from California state employees - <AUTHOR> http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2011/01/11/BA661H7E1T.DTL&tsp=1

<comment><USER2> I appreciate cosmetic improvements as much as the next guy, but my cynical bastard side thinks that cell phones are cheap and ostentatious (because real people actually pay for them) and pension/health benefits that are systematically looting the Californian pocket are expensive and stealthy (because we have convinced ourselves that no one needs to know the cost of these things).

$34 will pay the deferred benefits of, e.g., a California teacher for maybe a few hours if that.

<comment><USER3> This is Jerry setting a tone familiar to people who look at history. Last time he was governor, he ordered the sale of the Governer's mansion (to this day, governors must provide their own housing). He did not use the state's limo service but, rather, drove himself in a modest car.

This time around ... although it his own campaign money, not state money that pays for the inauguration ... he served hot dogs at the inauguration party rather than a fancy meal.

These are, in a way, theatrical gestures but they are neither empty gestures or pure pandering to the public.

They aren't empty because, for example, saving $20M on the state's cell phone bill won't balance the budget, but it is a hefty chunk of change.

They aren't pandering to the public because, as much as anything, the symbolism here is addressed inward on state government. If the governor is doing lots of stuff like this cutting at the top, then on down the hierarchy it becomes potentially embarrassing and career risking for high level civil servants and appointees not to follow in the same spirit. In other words, Jerry's gesture here helps to create a new political weapon: embarrassing someone that is choosing to protect rather than cut dubious perks. (Additionally, this circumstance makes it easier for lower-ranking bosses to cut discretionary perks that they control without invoking a riot among staff.)

Finally, this kind of thing is critical armor against the reverse political attack. In this case, for example, the unions can't get in his face and say "How can you expect us to cut salaries or benefits when your own staff and others are wasting state money on stuff like cell phones?"

<comment><USER2> I will apologize for my lack of faith when he makes meaningful cuts in benefits for unionized state employees, or starts cutting headcount. Let's call it 5% and add the proviso "and cutting future increases doesn't count, and cutting a buck today in return for a buck every week for forever doesn't count."

<comment><USER3> I don't think you have anything to apologize for. I think your concerns are valid. I was just filling in some detail about what conventional wisdom says Brown is doing with moves like this.

</comment></comment></comment></comment><comment><USER4> Many employees these days at (mature) companies only make their work cell phone number available in the company listing - so, if they need to be reached after hours, or in an emergency, the company provides them with a cell phone.

On the flip side, little things like cell phones, coffee machines, free water, laptop refreshes every three years - these are the things that Government Jobs are notorious for stripping away and making those jobs much less attractive to star performers. It's kind of like a spectrum, with Facebook/Google on one side, and Government positions on the other.

</comment><comment><USER5> This doesn't have as much to do with cell phones as it does with Jerry Brown's need to cut something. In other words I think he knows a lot of positions need cell phones but I think he also knows most people have personal phones they'll use if their work one is taken away. Since most people won't quit their job over the loss of a cell phone. So it's an easy cut to make (albeit an unfair one in many ways)

Sadly many of the union contracts specify employees be provided a cell phone so he's only going to get so far with this.

<comment><USER6> Read the article - he's not proposing to do away with state-issued phones altogether.

<comment><USER5> Read my comment - I specifically said "Sadly many of the union contracts specify employees be provided a cell phone so he's only going to get so far with this."

The order is simply too broad for him to have taken time to evaluate each position and decide who does and does not need a cell phone. Given that I will bet you all the money I have the cell phones he's taking away are the non- union employees and the ones who are getting to keep them are union employees.

</comment></comment></comment><comment><USER7> I'd have thought that the state would have more bargaining power to get a monthly cost substantially down from $34/month. Then again, I don't see why I need to pay for these people's cell phones. Jobs that require constant communications, like emergency services already have alternative systems in place. its just convenient for many other employees to have a cell phones.

<comment><USER8> IIRC, California state entities actually have a lot of legal shackles on their bargaining powers. (I can't remember the specifics, but this is what I've heard from state school employees tasked with purchasing equipment.)

</comment></comment><comment><USER9> Now if we could simultaneously make him governor of Illinois and do the same thing. Over here we are about to donate 2% of everyone's pay to one of the most corrupt state governments in the world, without any meaningful cuts at all.

</comment><comment><USER10> This is almost cause to speculate that California may eventually become solvent without additional bailouts.

<comment><USER11> $20 million saved in a year does not a balanced budget make.</comment></comment>


Algorithmic Trading is Not High Frequency Trading - <AUTHOR> http://talkfast.org/2011/09/13/algorithmic-trading-is-not-high-frequency-trading <comment><USER2> Accurate article? Yes I think so. Hairsplitting? A bit. Any content about the big picture? Afraid not.

Algo trading has been around longer than HFT. It was invented to protect the information that that a big order was being executed. This avoided the risk of front running by handing the order to humans or scaring liquidity providers by executing it all at once.

HFT came about when computerized exchanges began to compete with each other for business. Nowadays you go hunting for liquidity. Speed differentials are more important.

I think the OP is likely to agree up until here.

Today HFT in its worst form amounts to high speed computerized rumor mongering. You game the market by bluffing orders and trading faster than your customers. The regulators will never catch on and try to fix it even thought the remedies are many and simple. Moreover our attitudes about who owns information make it very difficult for us to even consider these simple solutions.

<comment><USER3> There are a massive number of HFT shops. Most of these are prop-shops rather than funds, as in they trade their own money and don't take investors. They are physically unable to front run their customers because they simply don't have customers.

I will give you that there are some big banks getting into HFT now, and that's a different story, but a statement like "HFT in its worst form amounts to high speed computerized rumor mongering." is wildly inaccurate and shows a complete lack of understanding of the industry.

Furthermore, there is a massive difference between algo trading and HFT. Technically speaking, yes, HFT falls under algo. However, HFT is about speed and making very little profit many times throughout the day, usually by providing liquidity.

Algos on the other hand, especially things like high end models aren't meant for HFT because they take larger amounts of time to run (ie: backtesting). These are used (for example) to determine misprices in the market that will pay off heavily in the long term, or (as others have mentioned below) to buy/sell a large quantity of shares in a way that it won't move the market in the other direction, rather than make an immediate, albeit tiny, profit.

<comment><USER2> I understand the industry quite well and from experience. BTW My only daggers were aimed at HFT.

Let me be clear. Anybody that puts an order in not expecting to get executed but to create favorable conditions for their next order is engaging in what I call "high speed rumor mongering". There are lots of variations of this game. Never happens? Always happens? You tell me.

But markets aren't chess. "Rumor-mongering" is a legal term I chose on purpose. It is generally prohibited because it destroys liquidity in markets, which hurts investors and issuers. The term is intentionally objectionable, but not inaccurate. Just don't trouble the regulators to figure it out.

</comment></comment></comment><comment><USER4> For one who works with HFT systems, an extremely refreshing clarification.

Though I do get a chuckle out of the extremely bombastic stories ("MAN OBSOLETE? COMPUTERS TAKING OVER!!!"), it's nice to see the record set straight. Sadly this will get 1/10000th of the page views of the garbage articles it dissects.

</comment><comment><USER5> Absolutely terrible blog post. Saying algorithmic trading isn't HFT is like saying a bird isn't an ostrich.

HFT is a subset of algorithmic trading. It's as simple as that. Not all algorithmic trading is HFT. But all HFT is algorithmic trading.

Algorithmic trading is any type of trading done based on an algorithm, and not based on "traditional investing principles". For example, "buy when the 10-day moving average crosses over the 20-day MA, and sell when the 10-day it crosses below 20-day". One of the most famous types of this is Richard Dennis and the Turtle Traders, where a successful commodities trader took a bunch of ordinary people and tried to turn them into traders using this method.

I'm also an algorithmic trader. Not a wildly successful algorithmic trader yet, but I'm still learning and growing, and I love it more than any programming venture I've ever been involved with. And I haven't taken a catastrophic loss yet, so that's good. I trade on 3 separate markets using different algorithms, and for the most part it is fully automated. I'll hold futures contracts anywhere from 1 seconds to 20 mins.

HFT is several orders of magnitude more intense. For the most part, they are types of arbitrage, where they can arbitrage a few cents worth of difference in stock prices between different markets, and make a few pennies per 1000 shares. Or they will arbitrage between the price of an ETF or futures contract and the underlying basket of stocks that it represents. These are the ones that need colocation and trade on the millisecond. The more nefarious ones are the ones that game the system, by "quote stuffing", by frontrunning large orders by institutions, or by creating volatility through momentum-trading.

Is there a downside to algorithmic trading? Sure. Algorithmic trading is what has turned the stock market from a predictive market of future earnings, into essentially a casino, where the predictive nature of the markets is completely dead. Instead, it's about thousands of computers running random number generators and picking up nickels every 10 ms. This is why I believe there will be market crashes every 7-10 years, and long term investing is dead.

But unfortunately, this is the reality of the system that we live in, and we have to adapt or die. Or you can just buy bonds and get a stable 3-5% return every year, which is nothing to shake a stick at.

<comment><USER6> What evidence do you have that the stock prices have recently become less predictive of future earnings? Was the market performing its predictive duty in, for instance, September of 1929?

<comment><USER5> Previously the vast majority of investors were buy and hold, where they believed in companies and that their earnings would increase. Of course, there were always traders like Jesse Livermore that traded off of order flow, but those were the minority. Most were like Warren Buffett where buying and holding was for the best.

Now the majority of trades are done by algorithms with no biases at all towards the earnings growth of a company, be it HFT, or statistical arbitrage, or through other quantitative models.

HFT accounts for 75% of daily volume, and by definition, HFT does not take into consideration things like future earnings growth, etc. For the most part, they simply find arbitrage opportunities and profit from them.

So stocks being bought and sold are not done based on the earnings potential of a company. Case in point, Citigroup before the reverse split was trading hundreds of millions of shares per day, not because so many people believed in the company, but because it was dominated by rebate traders, HFT, day traders, etc. I believe companies like Fannie Mae and Freddie Mac were trading millions of shares before they went pink slip, even though it was known that they were defunct.

<comment><USER6> You're talking about volume, not price. Increased volume should, if a market is performing "properly", accompany new information. If there's new information, there's a reason to trade. The examples you cited seem like evidence of the stock market's predictive value - for instance, increased volume in Citi stock was a piece of evidence that something about the security was expected to change.

Moreover, it's not true to say that stat-arb guys don't care about future earnings growth - they just use statistical methods to project it. To use a simplified example, a stat-arb guy might automatically buy shares in some small-cap automotive supplier if Ford rapidly increases in price. If the increase in Ford stock represents positive fundamental information about the auto industry, they've applied that information to the price of the supplier faster than a human would have and they'd make a profit. If, on the other hand, it represents concern about some scandal involving the Ford CEO, they've contributed to the noise and lost money.

<comment><USER5> I probably wasn't clear with my original statement. I said the stock market used to be a "predictive market of future earnings". What I meant more precisely was that the stock market used to be a market where people would make prediction about future earnings about companies. If you thought a company was doing well, you would buy and hold it, a la Warren Buffett. Some people traded order flow and other things, but the vast majority traded it as if it was a proxy for future earnings growth.

Over the years, that has changed. Once the internet hit and day traders became more common, it became more and more about buying stocks that will go up and selling stocks that will go down. I think people forget that even during the 90s, commissions for buying and selling stock were in the hundreds of dollars, not $8.95 like today. It was expensive for retail investors to buy and sell stock.

The time period for holding stocks has decreased sharply since then, where a few years ago rebate traders would buy and sell stock to just get the rebate from the exchanges, and now to where HFT eat the lunch of those same manual rebate traders.

The vast majority of trading done on the markets today is not done based on the quality of the company or the quality of the earnings, but based on how the stock will trade. Sure, there's still institutional trading, and I'm sure plenty of quant models make use of things like earnings growth, etc. And yes, things like news and fundamentals do cause prices to go up and down. But the _vast majority_ of daily trading, 75% of volume, is done by trading entities that don't care about fundamentals, and only care about miniscule movements in the stock price. This is why I use volume as evidence, because it demonstrates that most trading done isn't done because of the predictive nature of the stock market for future earnings, but because of the extremely short term predictive nature of the stock price itself.

That's why I said that it's less about predicting future earnings grow and more about making nickels every 10 ms. C trading 500MM shares a day is like people rolling dice every millisecond in the alley way and exchanging money upon every roll. The other example that I was searching for but couldn't recall was when GM went bankrupt and the stock was still trading over $1. This was purely trading activity even though the "future earnings" of the stock was 0.

It's become a casino where probability theory dominate and less about "I drink Coke so I should buy KO".

BTW, I'm not saying this is good or bad. I just believe this is how the markets are. The same thing happened when daytraders entered the markets during the dotcom boom. I do believe gaming the system, trying to "break" the markets with quote stuffing, etc, is wrong, but fundamentally I believe that the nature of the markets have changed, and anyone who wants to get involved in it should understand the nature of the change. Anyone who thinks that they should keep their money in mutual funds and let the mutual fund companies sip 2-5% every year for doing worse than the markets, and then also exposing yourself to market crashes every 7-10 years, I believe, are fools.

<comment><USER7> _I said the stock market used to be a "predictive market of future earnings". What I meant more precisely was that the stock market used to be a market where people would make prediction about future earnings about companies._

These two statements are not even discussing the same thing.

One statement discusses the practical computational power of a system. The other statement discusses the motivations of a majority of the people participating in that system.

</comment></comment></comment></comment></comment></comment><comment><USER8> From the article and other sources I've seen before, it seems that algorithmic trading is not necessarily high frequency, but that high frequency trading is necessarily algorithmic.

In which case is this not a rather thin hair to split?

<comment><USER9> Not really. HFT is a subset of algorithmic trading, where many small orders are placed to take advantage of intraday (or intraminute, or even intrasecond) shifts in the spread. A large strategic order executed through an algorithm is a different creature altogether.

The big problem when you place a huge buy or sell order is that it shifts the price in a direction you don't want it to go. For a large sell order, the price goes down, as the market becomes skittish about the security. For a large buy order, the price goes up, as the market becomes bullish and arbitrageurs quickly buy up securities to resell to you. So, many traders use algorithms to hide their trades. The purpose of these algorithms is to _avoid_ volatility, so they shouldn't be dangerous to the market, as long as they're designed correctly.

(Although, to be fair, algorithms may automatically stop trading when the market becomes too volatile, which contributes to flash crashes by reducing liquidity.)

<comment><USER10> "so they shouldn't be dangerous to the market, as long as they're designed correctly". Even if we accept the author's position, why would we also make the assumption that this software is designed properly and bug free?

<comment><USER11> I guess it depends on the stakes, and how well the traders understand (the risks of) software development to pay for the quality, testing, and maintenance.

 _"This isn't just some human lives we're playing with, this is serious! It could cost us billions!"_

</comment></comment></comment></comment><comment><USER12> I always find it interesting how much vitriol there is against automated trading, even among programmers. Too many people seem to believe that a small number of, ultra resourceful, nefarious folks are using unfair means to "game the system." The truth, as usual, is less interesting.

Doing this type of trading doesn't require millions of dollars and teams of PhDs. You don't have to know the right people and you don't have to know any secret handshakes.

Critics of high frequency trading are almost always misinformed. Some of the most informed critiques I have read about this stuff are the following books:

"A Demon of Our Own Design: Markets, Hedge Funds, and the Perils of Financial Innovation" by Bookstaber

"Traders, Guns and Money: Knowns and unknowns in the dazzling world of derivatives" by Das

And Nasim Taleb's work.

\</comment><comment>- More to the point, the author is explaining something very basic (which journalists don't seem to understand): -Algorithmic trading is NOT a general term for all trading done with algorithms/computers. It refers to telling a computer to EXECUTE a specific trade. In other words, when your retirement fund decides to buy A LOT of AAPL, they naturally need to spread that trade over the whole day (or even several days). In the old days, human traders used to do it. Now it is mostly done by computer programs.

This is different from the kind of trading where a computer decides WHAT to trade (NOT HOW to trade). This kind of trading involves so many different strategies that it is silly to lump them together.

There seem to be other misconceptions: -The best and the brightest are working in Finance, instead of doing things more beneficial to society.

A quant colleague of mine, who has a PhD in Physics from an Ivy League school told me that he, and many of his friends, left academia because there were simply no positions for them.

-75% of trading is now automated, it is just computers trading with each other.

I hope someone will correct me if I'm wrong but I have never figured out if this 75% includes algo trading. If it does include algo trading (my guess is that it does), then I'm surprised it is not 100%. That is like saying 95% of TV channels are controlled by remote-control devices.

-People seem to think that wall-street traders make their money by "trading ahead" of mom & pop investors: your Dad buys 1000 shares of microsoft, a wily trader puts your dad's order on hold, buys it for himself, raises the price, sells his shares to your dad at a higher price...thereby making money off your dad.

Your broker is not allowed to 'trade-ahead' of you. At least in the places where I have worked, this is taken very seriously. Interestingly, high frequency traders (who are most frequently accused of this) don't actually have access to customer order-flow. High frequency trading hedge funds don't generally have any client orders. Places where the two co-exist are forced to have seperation. Traders from one department cannot share information with the other. As more and more client facing firms (sell-side) become automated, the chance of them actually coding up such cheats is even dumber.

Flash trading is often given as an example of people, in cahoots with exchanges, trading on others' order information. As far as I know, "flash" functionality exists to help clients trade more effectively. Large traders are VERY concerned about letting the whole market know that they are interested in some stock. Some exchanges offered the following functionality: if you are interested in buying a stock, you have the OPTION of giving other members of the exchange a chance to trade with you. If no one takes you up on the offer, then the order goes to the wider market.

I have to admit that a laywer friend told me that he opposes this functionality at his firm. If someone _really_ needs to know more, I suppose I could ask him to explain.

-High frequency traders trade so fast that mom & pop simply can't compete with them. Their computers/networks are just too fast and they can get closer to the exchanges than anyone else.

High frequency traders are not competing with mom & pop, they are competing with market makers. If two people hear a news item, the one closer to the exchange will naturally get the trade done faster (presumably at a better price). The same is (generally) true of people on the East Coast vs rest of the country (let's assume US financial system). The same is true of people who can click their mouse faster. Besides, there is no moral reason your Mom should be able to dump her Enron stock faster than Joe Trader.

etc., etc., etc. \</comment><comment></comment><comment>-

I should add that I am actually not at all comfortable with the role finance plays in world economy. I can't call myself a critic since being critical requires more complete understanding.

I am specifically opposed to things like direct market access. This is where any Joe Blow can use an API to setup his trading system. If he accidently leaves an infinite loop in his code, he can cause real problem. I remember sweating bullets (and almost trembling) when my boss asked me to flip the switch on the trading system I wrote. In reality, there are at least some protections built in to keep this from happening. However, I would like to see more uniform, consistent and better advertised rules.

I am also against the ability to trade by borrwing money from brokers (margin trading or leveraged trading). If an individual trader screws up, they wipe themselves out. If they borrowed money, then the consequences of their bad trades starts to seep out to others. If more than a handful of traders, trading on margin, go belly up, the lender could be in trouble as well...you can see how this could ripple across a system.

Closely related to allowing trading on margin is reliance on models. Say you have calculated that two stocks always move together. You _and your lender_ are so sure of this correlation that they think of it as the truth. What if your calculations or your assumptions were wrong? The consequences of this mistake may not be linearly related to the risk you thought you took. Read Nasim Taleb's work on this for more.

Finally, those who smell something fishy should broaden their concern beyond just modern trading system or even complex derivatives. I can see no principal, within the framework of free markets and individualism, which leads to condemnation of ever more automated and faster trading, more complex instruments and more dependence of finance. The best moral principal, I can think of, which opposes the current state of affairs, is the one uttered by Martin Sheen's character in the movie Wallstreet: "Create, instead of living off the buying and selling of others."

Wallstreet 2 was a piece of shit.

<comment><USER13> > I am also against the ability to trade by borrwing money from brokers > (margin trading or leveraged trading). If an individual trader screws up, > they wipe themselves out. If they borrowed money, then the consequences of > their bad trades starts to seep out to others. If more than a handful of > traders, trading on margin, go belly up, the lender could be in trouble as > well...you can see how this could ripple across a system.

In theory, shouldn't those giving the loans account for the risk and thus be protected from wiping out themselves?

<comment><USER14> This is exactly what happened during the stock market crash of 1929, and regulations were put into place in the 1930s to prevent excessive margin leverage that might result in liquidity problems at brokerages (and in the banks that lend to them). These regulations have been in place since then and probably mitigated the effects of the dot com crash in 2000. See <http://en.wikipedia.org/wiki/Regulation_T> as a good starting point for research.

Interestingly, I read somewhere that there were similar regulations regarding residential mortgage loans that were repealed during the 1980s, does anybody have a reference to this? I think that requiring a 20% equity/debt ration when originating or refinancing a mortgage loan probably would have made the 2008 real-estate crash look a lot more like the dot com bust and would have saved a lot of economic pain.

</comment></comment></comment><comment><USER15> I'd argue that there's more good than bad about algorithmic trading. People making decisions based on fear and adrenaline is much more dangerous than setting a pre-determined course and sticking to a mathematical model. Besides, it's not like they just set up these programs and forget about them. If there's some sort of flaw in the algorithm the trader isn't just going to bang his head into the wall while he loses millions; he's going to fix the algorithm.

</comment><comment><USER16> Approx 99% of what is written about algo and high-freq trading is written by people who don't have a clue, have never worked in a trading environment (let alone actually traded) and think they're some kind of expert because they've read an article or two. Just remeber that the next time you read an article (or a comment about an article) on algo/high-freq trading.

</comment><comment><USER17> This is wrong. Algorithmic trading can be fully automatic as well. It just doesn't need to operate on short time windows as HFT does.

</comment><comment><USER18> execution and portfolio construction are separate things.

you can do both algorithmically, or manually, or a mix.

</comment><comment><USER19> For those that are interested:

Here is a video of an extremely interesting talk, entitled "Human Traders are an Endangered Species!", by Dave Cliff who's involved with the Foresight project:

[http://trading-gurus.com/human-traders-are-an-endangered- spe...](http://trading-gurus.com/human-traders-are-an-endangered-species/)

and more information on the Foresight project itself:

[http://www.bis.gov.uk/foresight/our-work/projects/current- pr...](http://www.bis.gov.uk/foresight/our-work/projects/current- projects/computer-trading)

</comment><comment><USER20> Are there not hedge funds that attempt to use algorithms to spot longer term (ie. days, weeks, months) market trends and then buy and sell on that information? I think it's pretty crazy to say that humans will always make the decisions, computer can process more information faster then any human can. At some point computer programs will be able to make more accurate market predictions then humans, and at that point the "robots" really will be in control.

<comment><USER21> Though we still haven't reached the level where programs write themselves.

</comment></comment><comment><USER6> Isn't the claim that algorithmic trading will never replace human decision making basically equivalent to the claim that humans will never construct strong AI?

<comment><USER21> Yes. But replacing (or augmenting) just most trading instead of all trading requires less than strong AI.

</comment></comment><comment><USER22> In your opinion, Jeff, was the 2010 Flash Crash the work of HFT, or Algo trading? Maybe both?

<comment><USER5> The 2010 flash crash was caused by "blackhat" HFT traders trying to game the system.

It was shown that one, some, or many HFTs were involved in "quote stuffing" which is bidding for stock and then pulling the order, something like 100k times per second. This gave the appearance of liquidity and demand, but it was fake, because as soon as someone would bid for the stock, they would pull their order. But another use of this was to essentially slow down the "ticker tape" of the NYSE. What was happening was that the "ticker tape" that showed the current bids and asks was slowing down, and by doing this, some HFTs could make use of the latency arbitrage. Colocated HFTs got their quotes for the best bids and asks directly from the exchanges, but other people were getting their quotes from the NYSE, so they were behind. I believe they were something like 30 seconds behind, so what would happen is that the HFTs had full reign to take advantage of others being blinded like this.

Of course, the side effect of this was that they "broke" the markets. Because of this latency, the NYSE suspended the markets temporarily, which then had the unintended consequence of forcing all the bids and asks to flow into the smaller exchanges, which didn't have the liquidity to handle the orders. There were so many sell orders, that basically all the buy orders for some stocks got taken out, causing the prices to plummet down to 1 cent or something like that.

I'm expecting another flash crash to occur at some point, so whenever I see heated market action, I place a bunch of trades around 25% below the current stock price, which I believe is just above the limits that the exchanges would use to roll back bad trades. (Un)fortunately, it hasn't happened yet, but I'm sure at some point it will.

<comment><USER23> > I place a bunch of trades around 25% below the current stock price

Funny, we sat around trying to figure out the right price and this is what we came up with as well.

Too bad this doesn't show up in second level quotes, it would be a good leading indicator of what funds in general thought the chance of a crash was on any given day:)

<comment><USER5> I place a limit order, which I guess you could see if the depth were deep enough, but I could very well have programmed an algorithm to just monitor the prices and do market orders instead, which you definitely wouldn't see. I'm sure most traders do it that way.

The interesting thing is that on the day of the Flash Crash, if I'm not mistaken the ES futures contract bounced exactly off the 200 day MA. So, one thing that the flash crash revealed is a lot of algorithms programmed into the markets that would normally never have been revealed. So if you want, keep a floating order just above the 200 day and you might make a few dozen points in a few mins, just like May 6, 2010!

<comment><USER23> > but I could very well have programmed an algorithm to just monitor the > prices and do market orders instead, which you definitely wouldn't see.

yes, but then you run the danger of your order not getting to the exchange in time and buying at the very bottom after everyone else has been filled.

We nixed this idea as being too risky:(

</comment></comment></comment></comment></comment><comment><USER24> by the way, the original article (now) opens with "Algorithmic trading, including high frequency trading (HFT)" and not "Algorithmic trading, also known as high frequency trading (HFT)"

</comment><comment><USER25> Why HFT is opposing Tobin tax?

<comment><USER26> Perhaps a better question is why Tobin himself now opposes the Tobin tax?

</comment></comment><comment><USER27> I think the author is actually wrong on this algo trading is defined as programs taking the decision, how fast this happens determines whether it is high frequency. Computer aided execution is called smart order routing..... just saying :)</comment>


Competition to reward Cameroon's best technology projects - <AUTHOR> https://www.iafrikan.com/2020/08/04/challenge-to-reward-cameroons-best-ict-projects/ <comment><USER2> If Cameroon really wants to encourage a technology industry, a great start would be not shutting off the internet for months to punish regions of the country that don't agree with the president politically.

[https://qz.com/africa/1349108/cameroons-internet-shutdown- in...](https://qz.com/africa/1349108/cameroons-internet-shutdown-in-blacked- out-documentary/)</comment>