Recovering Nintendo's Lost SimCity for the NES - <AUTHOR> https://gamehistory.org/simcity/ <comment> bjelkeman-again It is sad not having the original SimCity on something like the iPad. The version they offer is some abomination trying to be FarmVille begging for cash at every turn.

<comment><USER2> It would be theoretically and easily possible, but legally impossible to port the original C version of SimCity released under GPLv3 (called "Micropolis") to the iPad, because of the anti-Tivoization clause, it's a violation of the GPLv3 to put it on the Apple app store.

[https://en.wikipedia.org/wiki/Tivoization](https://en.wikipedia.org/wiki/Tivoization)

[https://apple.stackexchange.com/questions/6109/is-it- possibl...](https://apple.stackexchange.com/questions/6109/is-it-possible-to- have-gpl-software-in-the-mac-app-store)

[https://github.com/SimHacker/micropolis](https://github.com/SimHacker/micropolis)

However there's nothing stopping you from running one of the versions of Micropolis that's been rewritten in JavaScript to run in the web browser (because it's distributed via the web instead of on the App store), or contributing to those projects to make it run well on the iPad.

[http://micropolis.mostka.com/](http://micropolis.mostka.com/)

[https://www.graememcc.co.uk/micropolisJS/](https://www.graememcc.co.uk/micropolisJS/)

<comment><USER3> > because of the anti-Tivoization clause, it's a violation of the GPLv3 to put > it on the Apple app store

Ah, I always knew there was some anti-Tivoization in there, but didn't really dig into what it truly covered. So in other words, you could have a highly successful iOS app you sell, that you release under the GPLv3, and nobody should be legally allowed to publish it under the official App Store. They could only potentially contribute bug fixes, and licensing their commits back to you sounds a bit like it would need another license from their code.

That kind of sucks that the App Store is not technically compatible, I would of thought due to JailBreaking it would of been technically allowed.

<comment><USER4> _"They could only potentially contribute bug fixes, and licensing their commits back to you sounds a bit like it would need another license from their code."_

They could also port it to Android and release it there for free, or even sell it there (while offering all buyers the source code, to comply with the GPL)

<comment><USER3> This is true although might be somewhat tedious. I forget that translating code is also covered by the license.

</comment></comment></comment></comment></comment><comment><USER5> Oh, thank FSM. The private collector allowed them to dump a ROM.

[https://archive.org/details/simcity-nes](https://archive.org/details/simcity- nes)

</comment><comment><USER6> I had inherited my big brothers C64, along with a couple of paper notes on how to start games. I was very young, around 6 years old.

This article finally revealed to me that weird helicopter game I had played on the C64. The memory of flying over an ocean with a helicopter had stuck with me but not the title. I can't believe I played that title, and it was the inspiration to Sim City! Which I later in life played a lot of.

<comment><USER7> I _think_ I remember playing that in Russia, too - we had friends who had imported video game consoles, and that helicopter game looks very familiar.

</comment></comment><comment><USER8> In 1990 I was a kid, and there was a Japanese kid across the street with a Super Famicom. In addition to being floored by Super Mario World shortly before it came to the US I had a strong impression of SimCity and Dr. Wright with Japanese speech bubbles I could not understand.

<comment><USER9> Interesting, never thought to dig for non english versions of the game

[https://duckduckgo.com/?q=simcity+superfamicom&t=ffab&atb=v1...](https://duckduckgo.com/?q=simcity+superfamicom&t=ffab&atb=v124-5a_&iax=images&ia=images&iai=https%3A%2F%2Forig00.deviantart.net%2Fdcb4%2Ff%2F2015%2F113%2Fb%2F5%2Fsimcity_super_famicom_japanese_import_by_dragontamer272-d8qrdvh.jpg)

[https://proxy.duckduckgo.com/iu/?u=http%3A%2F%2Farcticsunbur...](https://proxy.duckduckgo.com/iu/?u=http%3A%2F%2Farcticsunburn.com%2Fwp- content%2Fuploads%2F2012%2F09%2FSimCity-Super-Famicom-257x300.jpg&f=1)

ps: crazy, while looking at these, my nose started remembering smells of that era..

</comment></comment><comment><USER2> As much as I love this article and the work CaH4e3 has done disassembling, documenting and improving SimCity, and the work and mission of the Video Game History Foundation and the Internet Archive, I have to question what the article means by the section header "The SimCity Open Source Project".

Is there an actual project calling itself that, or is that just a figure of speech that the writer of the article used (inaccurately)? Because abandonware, unpublished or reverse engineered software is not automatically open source, which has a very specific legal definition.

And SimCity is a trademark that is very much still in use and aggressively protected.

[https://www.konitono.com/ea-kills-open-source-version-of- sim...](https://www.konitono.com/ea-kills-open-source-version-of- simcity-2000/)

The original SimCity source code, based on the Mac version that I ported to Unix using TCL/Tk, was relicensed by Electronic Arts under GPLv3 for the OLPC project, and EA had some very specific conditions for using their trademark "SimCity" (for example, it had to be reviewed and approved by EA's QA department to protect their brand name "SimCity", or else released under another name like "Micropolis").

[https://medium.com/@donhopkins/open-sourcing- simcity-58470a2...](https://medium.com/@donhopkins/open-sourcing- simcity-58470a275446)

[https://medium.com/@donhopkins/har-2009-lightning-talk- trans...](https://medium.com/@donhopkins/har-2009-lightning-talk-transcript- constructionist-educational-open-source-simcity-by-don-3a9e010bf305)

Also the GPLv3 license itself has some very specific conditions about the use of the code. (For example, the Anti-Tivoization clause forbids publishing an app based on the code on the Apple app store.)

[https://en.wikipedia.org/wiki/Tivoization](https://en.wikipedia.org/wiki/Tivoization)

The full license and a simpler explanation is shown here:

[http://wiki.laptop.org/go/SimCity](http://wiki.laptop.org/go/SimCity)

>In case this confuses you, here is a simpler explanation. The code is free software. But the code as released by EA uses EA trademarks. You cannot modify the code and distribute it unless you (1) make it clear to the player that you have modified it, and (2) remove all the EA trademarks from the game. (You also have to follow all the other rules in the GPLv3, the EA additional terms, and the copyrights of other contributors. This was just a very brief summary.)

The "Micropolis" project is based on that original code, which has been cleaned up, documented, and translated to other languages, but it uses the name "Micropolis" (SimCity's original working title) instead of "SimCity" because of that trademark restriction.

There was one official version of GPLv3 "SimCity" released for the OLPC, based on the TCL/Tk version I developed for DUX Software, which went through EA's QA process and was approved for release by EA to be shipped with the OLPC. But all subsequent versions and derivatives were called "Micropolis", to avoid the need to go through that complicated approval process again.

[https://donhopkins.com/home/olpc-ea- contract.pdf](https://donhopkins.com/home/olpc-ea-contract.pdf)

EXHIBIT B

EA TRADEMARK AND LEGAL NOTICE:

"SIMCITY TM & (c) 1989 - 2007 Electronic Arts Inc. All rights reserved. EA does not support this software. For technical support visit: [http://wiki.laptop.org/go/SimCity](http://wiki.laptop.org/go/SimCity) or email email@example.com.

RESTRICTIONS ON USE:

OLPC shall not reproduce or use (or authorize the reproduction or use of) the EA Trademark, or any other trademark, service mark, service name, trade name, designation or logo of EA, in any manner whatsoever other than as expressly authorized by this Agreement. Furthermore, except as authorized hereunder, OLPC shall not reproduce or use any service mark, service name, trade name, trademark, designation or logo confusingly similar to the EA Trademark or any other trademark, service mark, service name, trade name, designation or logo of EA.

OLPC shall mark each use of the EA Trademark with either the superscript ® symbol or the superscript ™ symbol as set forth above adjacent to such EA Trademark. EA may at any time, and from time to time, amend this Exhibit B.

OLPC shall also take such other steps as may reasonably be requested by EA to evidence EA's ownership and license to OLPC of any of the EA Trademark, including, without limitation, execution of registered user agreements if required by applicable law.

<comment><USER10> > Is there an actual project calling itself that, or is that just a figure of > speech that the writer of the article used (inaccurately)? Because > abandonware, unpublished or reverse engineered software is not automatically > open source, which has a very specific legal definition.

Open source does not have a "very specific legal definition". Many different people use that term to mean many different things, the chief commonality tending to be "can you read the source code". Yes, OSI has a specific definition that goes beyond that, but OSI is not a legislative or judicial body, nor do they have authority from any such body to be involved in regulatory activities (contrasted with, say, the Amateur Relay Radio League, or Civilian Marksmanship Program). And personally I hew more towards the FSF's views on the matter than OSI's.

Anyway, it's pretty common in the open source world for a specific name to be trademarked, or assets to be copyrighted, while still making the source itself open. Some examples include SimCity vs Micropolis, Chrome vs Chromium, and Firefox vs IceCat. I'd argue that such projects still count as open source, because the source itself is open, even if you can't use the name or non-code assets. Non-code assets like names, graphics, audio, and documentation are commonly available under different terms or licenses anyway, e.g.: [https://wiki.wesnoth.org/Wesnoth:Copyrights](https://wiki.wesnoth.org/Wesnoth:Copyrights) Pretty much everyone (OSI, FSF, etc.) agree that code-specific licenses like GPL, MIT, BSD, and Apache don't make so much sense when talking about things that aren't software, hence the existence of things like GFDL, CC, etc.

<comment><USER2> >I'd argue that such projects still count as open source, because the source itself is open, even if you can't use the name or non-code assets.

They're open source because of the specific licenses they use, not because "you can read the source code". And the NES SimCity code definitely isn't licensed under anything resembling an "open source" license, even in the most vague least technical sense of the term, "you can read it". It was never sold as a product or meant to be distributed.

My question was whether "The SimCity Open Source Project" is an actual "thing" with a specific open source compatible license, or if it was just vague hand waving like "the source is open because somebody disassembled and commented it" that the article author meant as a metaphor.

<comment><USER10> Yeah, I was talking about the open sourced SimCity for PCs, definitely not the NES one.

</comment></comment></comment></comment><comment><USER11> I loved the analysis of the soundtrack embedded as a YouTube video [1] about halfway through the article. The composer, Soyo Oka, only brought one song from the NES version into the SNES version. The author of the video walks you through each track and explains what channels were used, what can be learned about the waveforms, how it compares to other NES music of the period, etc.

[1] [https://www.youtube.com/watch?time_continue=791&v=HmJP5EFUEp...](https://www.youtube.com/watch?time_continue=791&v=HmJP5EFUEpw)

</comment><comment><USER2> Here's some more information on the design of SimCity:

Will Wright on Designing User Interfaces to Simulation Games (1996)

A summary of Will Wright's talk to Terry Winnograd's User Interface Class at Stanford, written in 1996 by Don Hopkins, before they worked together on The Sims at Maxis.

[https://medium.com/@donhopkins/designing-user-interfaces- to-...](https://medium.com/@donhopkins/designing-user-interfaces-to- simulation-games-bd7a9d81e62d)

>SimCity Classic:

>Unfortunately I didn't type the notes from this part of the talk in, but it's been well covered elsewhere. Chaim Gingold's PdD dissertation on "Play Design" has some excellent in-depth analysis of SimCity as a cultural artifact, its code, algorithms and design, the story of open sourcing SimCity, his SimCity Reverse Diagrams, and many interesting quotes from interviews with Will Wright and other game designers. It includes a fascinating chapter about Doreen Nelson (who wrote the original SimCity Teacher's Guide) and her lifelong work on Design Based Learning (formerly City Building Education):

Gingold, Chaim. "Play Design." Ph.D. thesis, University of California Santa Cruz, 2016.

[https://search.proquest.com/docview/1806122688](https://search.proquest.com/docview/1806122688)

>I did my Ph.D. research on play and the history of computing. My thesis argues that it is productive to consider playthings, playmates, playgrounds, and play practices as constituting a set with shared design characteristics. SimCity, a software plaything that confounds game-centric approaches (e.g. game studies and game design), is the keystone in an arch of case studies that takes us from some of the earliest examples of computer simulation all the way to model cities enacted with children, cardboard, and costumes, and unusual playgrounds made of junk.

Chaim Gingold: [http://chaim.io/](http://chaim.io/)

Open Sourcing SimCity, by Chaim Gingold

Excerpt from page 289–293 of "Play Design", a dissertation submitted in partial satisfaction of the requirements for the degree of Doctor in Philosophy in Computer Science by Chaim Gingold.

[https://medium.com/@donhopkins/open-sourcing- simcity-58470a2...](https://medium.com/@donhopkins/open-sourcing- simcity-58470a275446)

SimCity reverse diagrams. Chaim Gingold (2016):

[https://lively- web.org/users/Dan/uploads/SimCityReverseDiagr...](https://lively- web.org/users/Dan/uploads/SimCityReverseDiagrams.pdf)

Doreen Nelson: [https://www.cpp.edu/~dnelson/aboutdoreen.html](https://www.cpp.edu/~dnelson/aboutdoreen.html)

[https://en.wikipedia.org/wiki/Design- based_learning](https://en.wikipedia.org/wiki/Design-based_learning)

[http://www.oac.cdlib.org/findaid/ark:/13030/c8p55t3m/entire_...](http://www.oac.cdlib.org/findaid/ark:/13030/c8p55t3m/entire_text/)

</comment><comment><USER12> I thought I remember seeing this at the Game On exhibition [https://en.wikipedia.org/wiki/Game_On_(exhibition)](https://en.wikipedia.org/wiki/Game_On_\(exhibition\)) but it must have been the SNES version.

</comment><comment><USER13> What's with their mobile layout? The URL bar doesn't disappear as I scroll. They must be doing something anonying.

Other than that, cool project. Just wish I could read more than 10 lines without scrolling and a quarter of my screen wasn't being wasted.

<comment><USER14> Same on desktop, appears to be a deliberate design choice to make the bottom, non-header, part as an overflow:auto div so it gets it's own scrollbar.

</comment></comment><comment><USER15> I remember having that. I loved SimCity on the desktop but honestly the NES version was a complete piece of shit. I don't comprehend why any would want to save it. It had an incredibly poor interface, terrible controls for that sort of game. It was just plain bad. I question the author claiming it was unreleased. Or I somehow managed to score a copy as a kid.

<comment><USER16> Is it possible you're thinking of the SNES, rather than the NES?</comment></comment>


Hacker News: Unknown or Expired Link - <AUTHOR> Why do i get a single line <body>" "Unknown or expired link" when I curl some YC pages? http://news.ycombinator.com/x for example.<p>If YC is full of such great product people and hackers, why wouldn't they use (searchable) permalinks? I'm assuming there's a reason for this, as its not the easiest way to do things. <comment><USER2> This has been discussed to death. Apparently you have to deal with it and it's not going to be fixed.

However, if anyone is curious about why it's happening, this is what the arc code is doing <http://news.ycombinator.com/item?id=3098863>

If you don't follow arc, here is a python and ruby approximation of the arc challenge <http://news.ycombinator.com/item?id=3098863>

[https://github.com/rahulkmr/musings/blob/master/ruby/sinatra...](https://github.com/rahulkmr/musings/blob/master/ruby/sinatra/closures.rb)

[https://github.com/rahulkmr/musings/blob/master/python/closu...](https://github.com/rahulkmr/musings/blob/master/python/closures2.py)

</comment><comment><USER3> I've wondered at times if PG isn't deliberately leaving this problem in place so that people who get annoyed by it are filtered out as users of the web site.

<comment><USER2> > I've wondered at times if PG isn't deliberately leaving this problem

Since you know about the implementation(I haven't looked closely), won't it need a complete overhaul to take closures out of equation? Or implement some sort of closure serialization(on-disk maybe)? Is there a third option where pg just bangs at the keyboard for a couple of hours, and done?

<comment><USER4> Just a home link or a page with the banner would be nice, so you don't have to faff about with your browser to get back to the homepage.

</comment></comment></comment><comment><USER5> It's funny, if Hacker News was the product of a startup it would have been redesigned, A/B tested and tons of features/tweaks added. Any growth would be seen as the result of those actions, however HN has grown anyway despite being stagnent for 5+ years.

Makes you wonder what all the software development really achieves, or if HN would be bigger still if they had done that - or if PG wants HN to be bigger at all.

<comment><USER6> pg puts his time and effort into managing the community, rather than the page controls.

He's repeatedly, periodically made comments on efforts to improve moderation, filtering, ranking, etc. And those efforts are evident in their effect upon content.

"Stagnant" is not an accurate description.

Finally, HN is a tool -- a tool for communication. In that respect, it works pretty well, and is actually somewhat UNIX-y, I'd argue. (E.g. leaving notifications to external add-ons, private communication to email et al., etc. HN focuses on its core purpose of posts, comments, and ranking (public discussion).)

P.S. This is, obviously, just my observation and opinion, FWIW.

P.P.S. Sorry -- rereading the parent comment, I think we are more like-minded than I first thought.

One might say pg has focused on the _message_ , rather than the presentation. Which has worked rather well. Although I think I and some others are also just fine with the presentation -- readability over eye candy, and with the effort put into other aspects of the site.

And... as some have observed, sometimes it is suspected or outright apparent that supposed "limitations" are actually a feature. For example, limiting disruptive, low S/N back-and-forth commenting.

I guess I've written all this in part for the benefit (if any) of some newer members who happen to read this. Experiencing HN over a longer period of time, I've found perhaps (presumptively) somewhat deeper insight into pg's and the moderators' approach and management.

<comment><USER5> I wasn't implying he had done the wrong thing particularly, graphic redesigns can be expensive and it's not clear how much value they add, he has clearly avoided them.

In my own experience I've found if you don't make at least small changes that people can see, early adopters think no one is working on the product and go away - because they perceive nothing will ever improve. This effect doesn't really apply to community or social networks though for the reasons you said.

</comment></comment></comment><comment><USER2> <http://news.ycombinator.com/item?id=3098756>

> why wouldn't they use (searchable) permalinks? I'm assuming there's a reason > for this, as its not the easiest way to do things.

It's straight forward, but not when you are using closures and continuations.

<comment><AUTHOR> So... hacker news chose to let their product be limited by an engineering issue?

<comment><USER2> Must we discuss the same thing that was discussed in the thread I posted the link to? Nothing new has happened since the last thread.

</comment></comment></comment><comment><USER7> Those kind of links are a great irritation for me when browsing and reading HN.

Instead of <http://news.ycombinator.com/x?fnid=KnmhPyrF1t> Why not for example: <http://news.ycombinator.com/news?page=2> ?

<comment><USER8> _Those kind of links are a great irritation for me when browsing and reading HN._

My work around for the "unknown or expired link" bug is to open page 1 of HN, then immediately open pages 2, 3, and 4, but in separate tabs.

That way, I never run afoul of that bug, and opening tabs is really easy in every modern browser.

I'd be interested to know how other people work around the bug.

<comment><USER9> Whenever I see it, I just leave. If you drop by every day or so, the 2nd and 3rd pages tend to be pretty redundant anyway.

</comment></comment></comment><comment><USER10> I'm fairly certain HN itself isn't actively developed.

If I remember correctly, there was quite a bit of teeth-gnashing over the state of password storage on HN awhile back, and it took the moving of mountains before things were changed (were they ever changed?).

<comment><USER11> Why would it be? It works well enough and it's not worth anything to add features. It's PG's experiment.

<comment><USER12> So the community here is PG's toy?

<comment><USER13> He said "experiment", not "toy". Spin it however you want, but nobody's forcing you to be here.

<comment><USER12> He did say experiment but that implies that PG wishes to manipulate the site in order to observe outcomes - when you manipulate something without due regard to the possible detriments it is known as "toying with" that thing. Ergo I asked the question as to whether PG's goal was merely to observe the community and manipulate it with no regard for the community itself or if it was perhaps something more lofty.

From what I've seen I think the community has grown organically out of the noble work of Ycombinator and that largely the tool of HN has been a relatively passive element in that growth. PG appears indifferent to HN as a tool - neither wanting to experiment with it, develop it, improve it, nor disregard it.

> _nobody's forcing you to be here_ //

Nice.

Do you feel passive-aggressiveness is the way to build a valuable community?

It was not spin it was enquiry with an attempt to dig in to the nature of calinet6's statement: calinet6's response makes it apparent that the important feature of the statement was not the choice of the word "experiment" but instead the apostrophe-s, ie that HN _belongs_ to PG. I feel that by asking the question in the way I did that I shortcut to this result.

[Aside: in general, would you say my presence as part of this community is to it's detriment?]

</comment></comment></comment></comment></comment><comment><USER14> <non_authoritative_opinion>

HN is a minimum viable product.

What gets addressed are behaviors which damage the community.

These are not usually related to visible features of the site.

Community issues created by the "Unknown or expired link" were addressed by the addition of the "No Procrastination" feature.

</non_authoritative_opinion>

</comment><comment><USER15> I totally agree, come on pg .... Unknown or expired link when I hit More after waiting too long... you can do better. I bet that is #1 on peoples wishlist for HN. That's actually perhaps the only problem I have with HN's design. Clean, simple, functional (except for that frequently annoying error message!!!) EDIT: spelling

</comment><comment><USER16> I wouldn't get my hopes up for any kind of feature at all for this site. I think PG kind of regrets making it at all since sites like this are about <random small percent> valuable information about startups and <random much larger percent> waste of time (e.g. pretty much any political discussion at all). I doubt he wants to make it even easier to waste time here.

</comment><comment><USER17> How about some keyboard navigation shortcuts? (left-right arrows). It works on <http://www.HnEasy.com>.

<comment><USER18> emacs style editing in the text box

<comment><USER19> Shouldn't that be a browser feature, rather than every website creating their own different implementation?

</comment></comment></comment><comment><USER20> The solution is to logout, then it works as intended.</comment>


Ask HN: What are your favorite podcast episodes, and who might enjoy them? - <AUTHOR> Some of mine:
Tim Ferriss with Naval Ravikant, also Naval with Shane Parrish/Farnam Street - who: people interested in business, philosophy, and self-improvement
Austin Allred with on IndieHackers - who: people who want to hear about a cool business and a thoughtful founder
Tim Ferriss with James Fadiman - people interested in psychedelics <comment><USER2> Revisionist History - McDonald's Broke My Heart

The copy on the website does a much better job explaining the episode than I could.

"McDonald's used to make the best fast food french fries in the world — until they changed their recipe in 1990. Revisionist History travels to the top food R&D lab in the country to discover what was lost, and why for the past generation we've been eating french fries that taste like cardboard."

I like all of the episodes, but this is a fun one to dig into if you've never listened before. Most of the episodes are more serious than this one.

[http://revisionisthistory.com/episodes/19-mcdonalds-broke- my...](http://revisionisthistory.com/episodes/19-mcdonalds-broke-my-heart)

<comment><USER3> Is it because people will keep coming back for bland food?

<comment><USER4> > why for the past generation we've been eating french fries that taste like > cardboard

We could both listen to the podcast but I'll guess and say it's because they don't use beef tallow in their fries anymore after vegetarians complained.

</comment></comment></comment><comment><USER5> Darknet Diaries EP 6 - Beirut Bank Job with Jayson E. Street - who: people who are interested in physical security and human factor security.

[https://darknetdiaries.com/episode/6/](https://darknetdiaries.com/episode/6/)

Darknet Diaries EP 7,8 - Manfred: Hacking Online Video Games for Fun - who: people who want to know why application security and input validation is so damn important

[https://darknetdiaries.com/episode/7/](https://darknetdiaries.com/episode/7/)

Darknet Diaries EP9: The Rise and Fall of Mt. Gox - who: for those who want to understand what happened with all the bitcoins in mt gox

[https://darknetdiaries.com/episode/9/](https://darknetdiaries.com/episode/9/)

There are many security podcasts out there but there are few that are as thrilling as the darknet diaries.

<comment><USER6> Never heard of this podcast before. Thanks for sharing it.

</comment></comment><comment><USER7> Framelab with linguist George Lakoff if you would like to understand the (hidden) logic behind the seemingly insane political speech, including presidential tweets.

Also, on the huge impact of and practice of framing conversations and arguments.

Opened my eyes in many ways.

I'd start with the first episode: [https://overcast.fm/+LU9RmhR6s](https://overcast.fm/+LU9RmhR6s)

</comment><comment><USER8> I really enjoy listening to hardcore history by Dan Carlin. Which is, no surprise, about history:) You could almost forget it's not an audio book from audible but a history podcast

<comment><USER9> A follow up for people that enjoy hardcore history, would be The History Of Rome by Mike Duncan. All of The History of Rome is available on Youtube, [https://www.youtube.com/watch?v=ItwGz43a_ak&list=PLmhKTejvqn...](https://www.youtube.com/watch?v=ItwGz43a_ak&list=PLmhKTejvqnoOrQOcTY- pxN00BOZTGSWc3)

It's really great that it's on YT because it allows you to listen to the podcast at a faster speed.

</comment></comment><comment> ng-user Recently, David Goggins on the JRE (Joe Rogan Experience).

I had no idea of this man's story prior to listening to the 2 hour podcast. It really sheds light on his incredible work ethic.

<comment><USER10> JRE did a good job with that interview. He has some good recent interviews on Jim Rome and Mark Divine (Sealfit). Definitely a good listen once or twice a month to hammer home a proper state of mind.

</comment></comment><comment><USER11> The Changelog - Building an Artificial Pancreas with Elixir and Nerves

I'm not sure why I found this so fascinating, but I did. The topic was about monitoring and managing Type 1 Diabetes with a homebrew Raspberry Pi.

[https://changelog.com/podcast/261](https://changelog.com/podcast/261)

Also TechDirt - "Copyright, Music & 'Theft'"

</comment><comment><USER12> First of, the episodes that Jerry Colonna took part in in Gimlet Media's podcasts, which are:

[https://www.gimletmedia.com/startup/shadowed-qualities- seaso...](https://www.gimletmedia.com/startup/shadowed-qualities- season-4-episode-3)

[https://www.gimletmedia.com/startup/running-a-family-and- a-b...](https://www.gimletmedia.com/startup/running-a-family-and-a-business- season-5-episode-4)

[https://www.gimletmedia.com/startup/sell-apartment-keep- star...](https://www.gimletmedia.com/startup/sell-apartment-keep-startup- season-6-episode-3)

And then I'd recommend Jerry's own podcast series: The Reboot Podcast

</comment><comment><USER13> Erwin McManus – The Problem With Love

[http://pca.st/episode/43d50de0-b75b-0133-2e57-6dc413d6d41d](http://pca.st/episode/43d50de0-b75b-0133-2e57-6dc413d6d41d)

Erwin McManus – Don't Give Up Your Freedom

[https://castbox.fm/episode/Don't-Give-Up-Your-Freedom- id5651...](https://castbox.fm/episode/Don't-Give-Up-Your-Freedom- id5651-id67098044?country=us)

Erwin McManus – Why Jesus?

[https://castbox.fm/episode/Why- Jesus%3F-id5651-id655230?coun...](https://castbox.fm/episode/Why- Jesus%3F-id5651-id655230?country=us)

</comment><comment><USER14> Here are two of my favorite Freakonomics podcasts:

1) Improving Social Trust would help the economy as much as a tax cut.

[http://freakonomics.com/podcast/trust-me- rebroadcast-2/](http://freakonomics.com/podcast/trust-me-rebroadcast-2/)

2) We underestimate our "tailwinds" and overestimate our "headwinds". This relates to many discussions, including issues of privilege:

[http://freakonomics.com/podcast/life-hard- rebroadcast-2/](http://freakonomics.com/podcast/life-hard-rebroadcast-2/)

</comment><comment><USER15> If you're fascinated by Supreme Court cases, I can't recommend highly enough Radiolab's More Perfect. They really open up your eyes into why cases were decided in that manner and the history behind the cases!

This podcast on the Commerce Clause is my favorite so far.

[http://www.radiolab.org/story/radiolab-presents-more- perfect...](http://www.radiolab.org/story/radiolab-presents-more-perfect-one- nation-under-money/)

</comment><comment><USER16> The wide-ranging podcasts/lectures hosted through the Long Now Foundation ([http://longnow.org/](http://longnow.org/)) are certainly worth exploring...

And nobody mentioned Cheap Astronomy yet ([http://www.cheapastro.com](http://www.cheapastro.com)) . Go for the physics and astronomy, stay for the great accent...

</comment><comment><USER17> Web3 with Fabian Vogelsteller by Software Engineering Daily [https://softwareengineeringdaily.com/](https://softwareengineeringdaily.com/)

Releases episodes 5 days a week, 40-60mins long, all related to software engineering but range from business development to blockchain backend.

The episodes are very structured which I really like but some interesting subjects are cut short to maintain the intended structure.

</comment><comment><USER18> Recode Decode- Interviews with leaders in tech (sometimes politics and entertainment) to talk about modern issues revolving the tech industry.

</comment><comment><USER19> Unfriend Me:

[https://itunes.apple.com/us/podcast/unfriend- me/id1290475944...](https://itunes.apple.com/us/podcast/unfriend- me/id1290475944?mt=2)

[http://feeds.frogpants.com/unfriendme_feed.xml](http://feeds.frogpants.com/unfriendme_feed.xml)

Touchy topics civily discussed.

</comment><comment><USER6> I am going to shamelessly link to a blog post where I answered this exact question.

[https://sheep.horse/2018/3/podcasts_worth_listening_to.html](https://sheep.horse/2018/3/podcasts_worth_listening_to.html)

My interests tend towards history, film, and music.

</comment><comment><USER20> Econtalk with Chuck Marohn of Strong Towns: an eye-opening discussion on why American towns and suburbs have their car-dominated form.

Conversations with Tyler -- Ben Sasse

I recommend listening to lots of econtalk, strong towns (I prefer the earlier ones), and conversations with Tyler.

</comment><comment><USER21> There were quite a few on the Tim Ferriss podcast that I enjoyed, but I did not have a great way to bookmark them.

I did share them with friends.

The Startup Chat with Steli and Hiten also had some great short episodes.

If you like Seth Godin, he has a new podcast called Akimbo that I have really enjoyed.

</comment><comment><USER18> Still Processing - Those who enjoy watching movies and talking about tech and thinking one step further about cultural impact/ implications of how movies/ tech are portrayed.

</comment><comment><USER22> Meta note: OP is asking for specific episodes, not just podcasts.

</comment><comment><USER23> Programmer Throwdown is pretty solid.. I don't have a favorite episode but they guys are great

<comment><USER24> I think you're referring to _Programming_ Throwdown ([http://www.programmingthrowdown.com/](http://www.programmingthrowdown.com/)).

</comment></comment><comment><USER25> Jim Florentine's podcast has pretty good commentary on cringey social media posting trends.

</comment><comment><USER26> To Be Continuous, by Heavybit - who: software developers, project managers, startup-founders

</comment><comment><USER27> Excellent question.

Joe Rogan and Jordan Peterson. (helped comb up some memes I had)(man, that politics is hairy like dreadlocks, like a relegion)

The Prisoner's dilemma on Radiolab. (opened up my 3rd eye, otherwise I can't stand their over-production)

</comment><comment><USER28> Waking Up with Sam Harris. Fascinating conversations for anyone who likes to have their mind changed.</comment>


Ask HN: Markdown or Latex for Lecture Notes? - <AUTHOR> <comment><USER2> Both, try pandoc you can write markdown notes with latex inside and it can produce bunch of other formats from that file, like pdf, html, LaTeX...

</comment><comment><USER3> I would suggest typora which supports markdown and automatically renders mathjax diagrams whose API is similar to LaTeX.</comment>


Sorry, Unix fans: OS X El Capitan kills root - <AUTHOR> http://www.infoworld.com/article/2988096/mac-os-x/sorry-unix-fans-os-x-el-capitan-kills-root.html <comment><USER2> I'm getting closer and closer to installing Ubuntu (or similar) on my Mac.

Has anybody tried dual-booting on a macbook pro, or similar? How does it compare to doing so on a non-Mac laptop?

<comment><USER3> I've currently got rEFInd dual-booting Yosemite and Ubuntu on a Macbook Pro 11,3 (15", mid-2014, 2.5GHz) - and it works just fine. It took some tweaking - the Linux distro didn't come with Wifi support right away, and it took some searching to figure out the problem (you'll have to install the Broadcom drivers manually from the Linux boot drive). But after that got worked out, it's become a pleasure to work with.

The most frustrating bit was actually getting it to output at a native 2560x1080 resolution for my LG Ultrawide. But, again, there's a driver for it. The only reason I haven't switched to it full-time is I haven't had the time/luxury of incorporating it into my current workflow. Too many deadlines. But I plan to, and until then I'll just keep using Yosemite.

</comment></comment><comment><USER4> well, [https://www.exploit-db.com/exploits/38371/](https://www.exploit- db.com/exploits/38371/) OS is getting popular, i.e. it is a decent target</comment>


How Universities Make Cities Great - <AUTHOR> https://www.bloomberg.com/view/articles/2018-03-06/how-universities-make-cities-great <comment><USER2> Kind of surprised that Arizona was the first non-small population state on the list.</comment>


Time scrolling - <AUTHOR> http://www.tedunangst.com/flak/post/time-scrolling <comment><USER2> pity it doesn't work with nvi as undo and redo are the same (u) and . to repeat</comment>


Web traffic impact of a TV press appearance - <AUTHOR> http://www.robertoalamos.com/what-will-be-the-impact-of-a-free-press-appearance-for-your-website <comment><USER2> Not my experience at all. Some of the biggest spikes in traffic I've ever seen were generated by major-network television coverage wherein the domain was simply mentioned a couple times. I think the deciding factor is whether the description of your site gets people excited -- "I have to see that!".</comment>


HN Classics: As We May Think (1945) - <AUTHOR> https://www.theatlantic.com/magazine/archive/1945/07/as-we-may-think/303881/?single_page=true <comment><USER2> You beat me to it by a day! And here I thought I was being clever. It's amazing how Xerox PARC's lineage can probably be traced to this essay, that's not the only interesting thing about it :)

Vannevar Bush's writings are going on my reading list this year and ironically so are Markus Wolf's.</comment>


Myers-Briggs types for developers compared to US population - <AUTHOR> http://developermedia.com/developer-personalities-audience-brief-report/ <comment><USER2> Don't know why this is seen as legitimate. MBTI makes the bad assumption that people that fall on either side of a bell curve (say in terms of extraversion) are categorically different people. More self-fulfilling than anything.

<comment><USER3> The way it was explained to me is that the letters are vastly less useful alone than with the scores. The score you get says where on that bell curve (approximately, depending on how well-posed the questions were) you lie in each of those scales. Not predictive by any means, but possibly insightful.

</comment></comment><comment><USER4> Pseudo-science.

And isn't it funny how just about everyone advertising their MBTI happens to be an INTJ?

If you encounter someone making hiring or dating decisions based on this, walk away.

<comment><USER5> It's a model. Like all models, it's wrong as soon as you delve into the details. Under certain circumstances it can be _useful_ , though.

The reason INTJs seem to be disproportionately drawn to it (actually, like most statements, that's inaccurate - in my experience INTJs and INFJs are most drawn to the MBTI, followed by other N types...which is what the theory would predict) is because INTJs like to make systems and models of how reality works, and MBTI is one model of how psychology works. Any halfway-mature INTJ (or person, really) will recognize that the model is _not_ reality, and that once you dive into the details, you'll find numerous ways where the facts don't line up with theory. But as a tool for orienting yourself, it's a handy first approximation.

<comment><USER6> So, where is the evidence that it is a handy first approximation? That is, that it makes any kind of testable predictions? Even if they don't always hold, there should be some correlations with some kind of quantifiable metric. So what quantifiable metrics to these personality categories correlate with?

<comment><USER7> As it happens, he answered exactly this question elsewhere:

[https://news.ycombinator.com/item?id=9412144](https://news.ycombinator.com/item?id=9412144)

The MBTI is reasonably well correlated with 4 of the "Big Five" personality traits, which are on good empirical footing.

[https://en.wikipedia.org/wiki/Myers%E2%80%93Briggs_Type_Indi...](https://en.wikipedia.org/wiki/Myers%E2%80%93Briggs_Type_Indicator#Big_Five)

</comment></comment></comment></comment><comment><USER8> "Why the Myers-Briggs test is totally meaningless"

[http://www.vox.com/2014/7/15/5881947/myers-briggs- personalit...](http://www.vox.com/2014/7/15/5881947/myers-briggs-personality- test-meaningless)

 _" There's just no evidence behind it," says Adam Grant, an organizational psychologist at the University of Pennsylvania who's written about the shortcomings of the Myers-Briggs previously. "The characteristics measured by the test have almost no predictive power on how happy you'll be in a situation, how you'll perform at your job, or how happy you'll be in your marriage."_

</comment><comment> ryan-allen The only model of personality taken seriously by academics at present is the five factor model [1].

It's well researched, the traits were not 'designed', rather the traits popped out of linguistic analysis and statistics, and it's stable across different populations and over most of a person's lifetime.

There is an open test called the IPIP Neo which has either 120 or 300 questions, which you can take online [2].

If you're really interested in what is being taught these days about the theory, this is a good set of lectures take takes you from the early theory of personality through to what is considered science today [3].

[1] [http://en.wikipedia.org/wiki/Big_Five_personality_traits](http://en.wikipedia.org/wiki/Big_Five_personality_traits)

[2] [http://www.personal.psu.edu/~j5j/IPIP/](http://www.personal.psu.edu/~j5j/IPIP/)

[3] [https://www.youtube.com/playlist?list=PL22J3VaeABQAhrMCQUa6s...](https://www.youtube.com/playlist?list=PL22J3VaeABQAhrMCQUa6sde_Y9DVbLYRv)

<comment><USER9> That's such a Virgo thing to say.

</comment></comment><comment><USER10> Ugh. This comes up so often on Hacker News that I've prepared a FAQ paragraph about how unvalidated the Myers-Briggs test is. Read the articles you'll find at the links for much more information than I have time to type here with arthritic fingers. The Skeptic's Dictionary discussion[1] is a good place to start, but there are other critiques of the test too. Don't miss the discussion of the National Academy of Sciences review of the test.[2] "Overall, the review committee concluded that the MBTI has not demonstrated adequate validity although its popularity and use has been steadily increasing. The National Academy of Sciences review committee concluded that: 'at this time, there is not sufficient, well-designed research to justify the use of the MBTI in career counseling programs,' the very thing that it is most often used for." Psychologists who really know about personality testing don't regard the Myers-Briggs test as a worthwhile test.[3]

An article from the _Washington Post_ newspaper sums up the matter pretty well:

"Now, 50 years after the first time anyone paid money for the test, the Myers- Briggs legacy is reaching the end of the family line. The youngest heirs don't want it. And it's not clear whether organizations should, either.

. . . .

"Yet despite its widespread use and vast financial success, and although it was derived from the work of Carl Jung, one of the most famous psychologists of the 20th century, the test is highly questioned by the scientific community."[4]

[1] [http://www.skepdic.com/myersb.html](http://www.skepdic.com/myersb.html)

[2] [http://www.psychometric-success.com/personality- tests/person...](http://www.psychometric-success.com/personality- tests/personality-tests-popular-tests.htm)

[3] [http://www.indiana.edu/~jobtalk/HRMWebsite/hrm/articles/deve...](http://www.indiana.edu/~jobtalk/HRMWebsite/hrm/articles/develop/mbti.pdf)

[4] "Myers-Briggs: Does it pay to know your type?" 14 December 2012

[http://www.washingtonpost.com/national/on- leadership/myers-b...](http://www.washingtonpost.com/national/on- leadership/myers-briggs-does-it-pay-to-know-your- type/2012/12/14/eaed51ae-3fcc-11e2-bca3-aadc9b7e29c5_story.html)

<comment><USER11> > _although it was derived from the work of Carl Jung_

A lot of Carl Jung's work is some of the most ridiculous pseudo-science that I've ever seen. MBTI is _less_ credible due to its relationship with Jung.

</comment></comment><comment><USER12> This survey was taken on CodeProject.com, a site which seems biased toward C#, C++, .NET, Java, and mobile devs.

Perhaps it's just that sample of developers who skew toward INTJ, ENTJ and INTP.

I suspect that the results would be different in a survey of developers from a more open source-focused community, e.g. if GitHub conducted that survey and a lot of idealistic open source developer types responded.

<comment><USER5> Google had (has?) an informal "just for fun" Meyers-Briggs type badge on the Intranet. Among people who participate, roughly 65% are either INTJ, INTP, or ENTJ, with a further 10% ENTP. INTJs alone made up about 30% of the company, vs. about 3% of the general population. Only about 10-15% were an S of any type (vs. about 75% of the population).

Yes, there's selection bias on multiple levels here. S-types tend to think that the MBTI is hogwash and so would be underrepresented in any voluntary poll. (The other majorly-overrepresented group was INFJs at ~7-8% vs. about 2% in the general population. In my experience, INFJs are not a significant portion of Google, but they _are_ a significant portion of people interested in the MBTI.) Google also has an INTJ founder and a culture very friendly to INTJs, which skews the numbers inside the company.

But I suspect that if anything, the open-source community would be _more_ biased toward the INTJ/ENTJ/INTP axis. The C#/C++/.NET/Java market has a large number of developers who are in programming because it makes for a good living, which is a more S-based trait.

</comment></comment><comment><USER13> That chart -- Ow, my eyes! The multi-direction, multi-frequency cross hatching (and it's wrong in the legend). The bars showing the difference (but only absolute value, ignoring sign) between the two other bars. The cheesy 3D effect. A Tufte Hall of Shame candidate.

</comment><comment><USER14> So, we have a marketing company that helps others advertise to developers based on Myers-Briggs results showing 3 main results? Guess I'm not supposed to be a developer since I keep scoring ENTP (why I've had to take the damn thing multiple times starting at 13 is a bar discussion on various jobs / government grants).

</comment><comment><USER15> Moral: Should answer INTJ whenever a recruiter searching for a "ninja/rockstar" developer asks my MBTI type.

</comment><comment><USER14> Looking at this thread and not arguing for / against the Myers-Briggs, I do have a question.

Has anyone reading this who took the test scored an S (sensing) instead of the N (intuition)? I see variance in the other three slots but not that one.

<comment><USER15> Yes, I scored an S (and I am a developer). IMHO, The reason why most people get an "N" and often INTJ is because all the cool answers lead one to be typed as INTJ (I score INTJ sometimes, but I was pretty sure I am not that sharp and did not score straight A's in school) . If one attempts the test thinking he is logical and unemotional as Dr.House or Dexter, he would end up being typed as an INTJ. A lot of the times questions are ambiguous and I choose an option as I just wanted to get done with the boring part. The interesting part is then later talking about what fiction character has what type and what celeb is of what type and then reading up /r/<MBTI>. I think the rest of the stuff like correlation with being a developer (and good developer if you look at INTJ forums/descriptions) is generally wrong because 1) people take the test thinking about what they want to be and not what they really are 2) Most of it is plain stereotyping and since S types are generally typed in as less logical, most developers' will end up not getting that as their results. 3) I believe (and have observed in my 20-something life) that hard work trumps everything in the end

</comment></comment><comment><USER16> Psychologists don't like this test because it's unscientific, and I agree. But something is up in that developers seem to be overwhelmingly INTJ and the rest of the population is not.

<comment><USER17> Could be that we answer ambiguous questions differently, not that we have different personality traits.

Still, I've noticed that there is a bias in the general workplace against people who are perceived to be introverts, and so I answer ENTJ if asked, which has only happened a couple of times.

</comment></comment><comment><USER18> On the validity of MBTI, the main use I've found is to use the eight functions as part of my vocabulary. It's a pretty handy approximation to be able to say to someone in conversation "wow, Stephen Fry has a really developed Fe" and have them know what you mean. There an approximation is all you need, and in exchange you get neat symbols to hang entire categories of ideas onto.

On the flip side, it's all too easy to move symbols around in your head without investigating whether the model you've built corresponds to reality...</comment>


Preemption Is GC for Memory Reordering - <AUTHOR> https://www.pvk.ca/Blog/2019/01/09/preemption-is-gc-for-memory-reordering/ <comment><USER2> Fuck yeah.

I was hoping that eBPF would be a renaissance of exokernel ideas. Part of the whole exokernel shtick was user programmable virtual machines on user/kernel boundary to generate new specialized kernel interfaces for the task at hand. They hoped to lower the barrier for crafting those new interfaces that a lot of experimentation would happen.</comment>


SpaceX says Crew Dragon capsule exploded due to exotic titanium fire - <AUTHOR> https://www.teslarati.com/spacex-crew-dragon-explosion-titanium-fire/ <comment><USER2> As someone on reddit pointed out:

"The following metals have been found to be incompatible with nitrogen tetroxide and must not be used: Aluminum 2024, Zinc, Aluminum 7075, Silver, K-Monel, Titanium, Brass Cadmium, Bronze Hastelloy, Copper, EZ Flow 45 Braze."[0]

[0]: Materials Compatibility with Liquid Rocket Propellants, [https://apps.dtic.mil/dtic/tr/fulltext/u2/866010.pdf](https://apps.dtic.mil/dtic/tr/fulltext/u2/866010.pdf)

<comment><USER3> >Boeing report published 1970

>SpaceX: "It is worth noting that the reaction between titanium and NTO at high pressure was not expected."

SpaceX did not expect a reaction known to Boeing almost 50 years ago. My guess would be that this is actually known by a lot of people in rocketry, since UDMH/NTO is a standard propellant - the Proton is entirely fueled with it.

I also guess that the titanium component of the valve is not normally exposed to the oxidizer, and only came in contact with it when the valve broke. It would seem that the simple issue of shattered valve fragments flying down the oxidizer line would have been sufficient to destroy the thruster irrespective of a titanium fire...

<comment> semi-extrinsic To give them benefit of the doubt, it could be that "the reaction (...) was not expected" is trying to say "we did not expect NTO to make contact with this valve". It was on a helium ullage line, after all.

<comment><USER3> I didn't include the followup statement from the SpaceX press release : "Titanium has been used safely over many decades and on many spacecraft from all around the world."

The implication being that there's just no way SpaceX could have suspected this problem because structural titanium use in a spacecraft would inform decisions regarding its use in contact with corrosive propellant.

Obviously, this was written by a PR person, not engineering management, but it plays to an image of SpaceX being a company to handwave past the hard-earned lessons of decades of "Old Aerospace" companies. They should be more careful in releasing these kinds of statements.

</comment></comment></comment></comment><comment><USER4> > To do this, helium is rapidly pushed through a check valve - designed with > low-molecular-mass helium in mind - to physically pressurize the propellant > systems. Unintentionally, the NTO that leaked 'upstream' through that valve > effectively was taken along for the ride with the high-pressure burst of > helium. In essence, picture that you crash your car, only to discover that > your nice, fluffy airbag has accidentally been replaced with a bag of sand, > and you might be able to visualize the unintended forces Dragon's check > valve (the metaphorical airbag) was subjected to when a "slug" of dense > oxidizer was rammed into it at high speed.

This paragraph really drove the point home for me. I was able to easily visualize the event.

<comment><USER5> Classic Water Hammer!

[https://en.wikipedia.org/wiki/Water_hammer](https://en.wikipedia.org/wiki/Water_hammer)

<comment><USER6> Well "classic" water hammer doesn't involve the water igniting with the pipe material... ;-)

<comment><USER5> Totally! You get a water hammer and thermite reaction all in one go! Eeeek!

<comment><USER7> Is metal burning with a non-metal-oxide oxidant a thermite reaction?

<comment><USER8> Aren't all these thermite oxidisers metals or metalloids?

 _Bismuth(III) oxide, boron(III) oxide, silicon(IV) oxide, chromium(III) oxide, manganese(IV) oxide, iron(III) oxide, iron(II,III) oxide, copper(II) oxide, and lead(II,IV) oxide._

[https://en.wikipedia.org/wiki/Thermite](https://en.wikipedia.org/wiki/Thermite)

</comment></comment></comment></comment></comment></comment><comment><USER9> Direct link to SpaceX press release: [https://www.spacex.com/news/2019/07/15/update-flight- abort-s...](https://www.spacex.com/news/2019/07/15/update-flight-abort-static- fire-anomaly-investigation)

</comment><comment><USER10> I've taken these from other commenters, but can someone rectify these apparently contradictory statements for me?

"The following metals have been found to be incompatible with nitrogen tetroxide and must not be used: Aluminum 2024, Zinc, Aluminum 7075, Silver, K-Monel, Titanium, Brass Cadmium, Bronze Hastelloy, Copper, EZ Flow 45 Braze."[0]

"Titanium is practically the only metal that can store NTO for long periods of time over a reasonably large temperature range." [1]

[0]: Materials Compatibility with Liquid Rocket Propellants, [https://apps.dtic.mil/dtic/tr/fulltext/u2/866010.pdf](https://apps.dtic.mil/dtic/tr/fulltext/u2/866010.pdf)

[1]: [https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/197200...](https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19720019028.pdf)

<comment><USER11> I think levels of impurities and surface treatment of the metal may cause variation in whether something is considered suitable or not?

For example, from [0] (which is declassified from 1974!) :

"Titanium can react violently with strong oxidizers if the oxi-dizer penetrates the oxidized surface layer."

"Free chloride, ions in nitrogen tetroxide can cause an accelera-tion of intergranular corrosion in titanium."

</comment></comment><comment><USER12> FTA: "...instead of a mechanical check valve (simple but still not 100% passive), the barrier between pressurant and oxidizer (as well as fuel, most likely) will be replaced with something known as a burst disk."

A burst disk comes from a different concept than a check valve. With a check valve, one presumably desires a fluid flowing in one direction—in this case the pressurant for the oxidizer vessel—and no back flow. In the rocket engine industry this setup tends to be used to maintain cleanliness. A burst disk, however, embodies the same concept as a relief valve—it prevents the pressurization of a system above its rated capacity. I fail to see how replacing a check valve with a burst disk fixes the problem and maintains the same system capability.

<comment><USER6> I think the idea is that the system is never intended to be depressurized once it's pressurized, so you don't need a check valve, you just need something to prevent backflow before the system is pressurized.

<comment><USER12> Aha. I have a better understanding after reading the actual SpaceX presser[0]. The SuperDraco thrusters are to be used _only_ for a launch escape scenario, so they would only be used once before a ground refit of the capsule. That being the case, a burst disk does make sense as a replacement for a check valve.

0: [https://www.spacex.com/news/2019/07/15/update-flight- abort-s...](https://www.spacex.com/news/2019/07/15/update-flight-abort-static- fire-anomaly-investigation)

<comment><USER13> The reason why they have a check valve is that the design was originally designed to be re-lightable for purposes including but not limited to abort. At this point, NASA only wants them used for abort so a burst disk is a simpler design but I guess they never updated the design to reflect the restricted purpose. That would fit with SpaceX's general design philosophy of building re-usability in well before the systems are actually due to be re- used.

</comment></comment></comment></comment><comment><USER14> Too bad "Some Birds Don't Fly"[0] is so expensive these days; interesting read on the early days of misslecraft

[0] [https://www.amazon.com/Some-birds-dont-Gary- Paulsen/dp/B0006...](https://www.amazon.com/Some-birds-dont-Gary- Paulsen/dp/B0006BU29W)

<comment><USER15> Ooh, I'll have to keep an eye out! Have you read Ignition! [0] to give a comparison?

0: [https://www.amazon.com/Ignition-informal-history-liquid- prop...](https://www.amazon.com/Ignition-informal-history-liquid- propellants/dp/0813507251)

EDIT: archive.org appears to have it: [https://archive.org/details/somebirdsdontfly00paul](https://archive.org/details/somebirdsdontfly00paul)

<comment><USER16> Relevant to this story is this passage from _Ignition!_ :

 _On December 29, 1953, a technician at Edwards Air Force Base was examining a set of titanium samples immersed in RFNA, when, absolutely without warning, one or more of them detonated, smashing him up, spraying him with acid and flying glass, and filling the room with NO₂. The technician, probably fortunately for him, died of asphyxiation without regaining consciousness.

There was a terrific brouhaha, as might be expected, and JPL undertook to find out what had happened. J. B. Rittenhouse and his associates tracked the facts down, and by 1956 they were fairly clear. Initial intergranular corrosion produced a fine black powder of (mainly) metallic titanium. And this, when wet with nitric acid, was as sensitive as nitroglycerine or mercury fulminate. (The driving reaction, of course, was the formation of TiO₂.) Not all titanium alloys behaved this way, but enough did to keep the metal in the doghouse for years, as far as the propellant people were concerned._

(RFNA is a mixture of NTO and anhydrous nitric acid).

</comment></comment></comment><comment><USER17> Ooh a titanium fire - that would be really cool to see. I wonder if it's possible to make titanium thermite as easily as aluminum thermite?

<comment><USER18> Most metals can be used to successfully make thermite when paired with appropriate metal oxides. It is a very simple thermodynamics equation that determines which combos work well. The main considerations are the net energy release of the reaction, which can vary widely, and the amount of energy required to bootstrap the reaction, which can be extremely high. Classic thermite -- aluminum and iron oxide -- is a middling combo but has the large benefits of being dirt cheap and low density.

Designing exotic thermites is a literal direct application of the elementary reaction thermodynamics that you learn in basic chemistry classes. Bootstrapping ignition is a bit more involved and often multi-stage.

<comment><USER19> The article says: "Rather, the cause lies in a more exotic and unanticipated chemical/material interaction between a plumbing valve, liquid oxidizer, and a helium-based pressurization system."

How can chemical interactions be "exotic"? Or did they mean "exothermic" or "exciting" or "esoteric"? Is "exotic" a technical term, or did the chemicals simply come from a distant foreign country, and how does that affect their physical properties?

[https://www.quora.com/What-are-exotic-compounds-in- chemistry](https://www.quora.com/What-are-exotic-compounds-in-chemistry)

Is there such a thing as non-baryonic titanium?

[https://en.wikipedia.org/wiki/Exotic_matter](https://en.wikipedia.org/wiki/Exotic_matter)

>Hypothetical particles and states of matter that have "exotic" physical properties that would violate known laws of physics, such as a particle having a negative mass.

I can understand why you'd want to fill a rocket with exotic matter of negative mass: to make it lighter! ;)

<comment><USER18> The term "exotic" in a chemistry context means one of two things.

First, it can mean observed chemistry that is seen neither in nature nor the lab under ordinary conditions. In other words, it is theoretically possible but the required conditions are so atypical that the expected probability of it occurring unintentionally are very small. I'm guessing this is the case that applies here.

Second, "exotic" can mean engineered chemistry that is far outside the standard industrial spectrum, typically because there is a unique application with very special requirements. Industrial chemistry is all about _price performance_ of the chemistry not absolute performance, but some use cases are more performance sensitive than price sensitive so people will design bespoke and unusual ("exotic") chemistry for the purpose. It is a curve. Everyone uses the cheapest chemistry that still does the job adequately.

</comment></comment></comment></comment><comment><USER20> Doesn't their solution preclude restarting the engines? Maybe that was never intended.

<comment><USER21> The Super Dracos are only intended to be ignited once, either for a launch abort or a propulsive landing.

<comment><USER22> Is it the case that, if used for propulsive landing (which is speculative at this point), each of the Super Draco engines would be turned on and then left on -- presumably, with variable non-zero thrust -- until landing has completed? It's not obvious to me that they wouldn't need to be throttled down to zero. Or is that not relevant so long as the pressure from the helium remains on throughout engine usage?

<comment><USER23> The latest I've heard on /r/SpaceX is that the propulsive landing is completely off the table for this vehicle.

I suppose they might retain the ability in case of a chute failure, but that would be it.

I'd still like to see them try it.

<comment><USER22> Musk says it's still on the table as a backup plan "pending NASA approval". Different commenters on /r/SpaceX have greatly varying estimates about how realistic that is.

[https://twitter.com/iamkostmos/status/1104510464627625984](https://twitter.com/iamkostmos/status/1104510464627625984)

I hadn't heard any thing from official channels since then.

<comment><USER24> > Musk says it's still on the table as a backup plan "pending NASA approval".

read: NASA says it's not happening.

</comment></comment></comment></comment></comment></comment><comment><USER25> Exotic Titanium Fire would make a great band name.

<comment><USER26> Too many syllables.

<comment><USER27> So, album then.

</comment></comment></comment><comment><USER28> "Rockets are tricky."

</comment><comment><USER29> Based on what just happened, this is somewhat alarming:

 _For the time being, NASA has published a tentative target of mid-November 2019 for Crew Dragon's first crewed launch to the International Space Station_

I'd rather fly 1,000,000 miles in a Boeing 737 MAX than risk one ride in this contraption. It surely needs quite a bit more unmanned testing before it can honestly be considered to be "man rated".

Of course, NASA has a long and sordid history of pushing spaceflight while playing down many potential catastrophic problems. The Shuttle problems prove that.

And there's no need to belabor Musk's shortcomings. As someone on HN recently quipped, in response to Musk's claim of full driving autonomy by 2020: _Tesla has an advantage here in that they don 't feel the need for their autonomy to be particularly safe._

<comment><USER30> Airliners are the safest form of transport ever devised. You're safer in an airliner than you are in the shower.

Space travel is one of the most dangerous forms of transport ever devised. Even the most insane, wildly optimistic estimates for the safety of the Shuttle were orders of magnitude more dangerous than an airliner.

Comparing the two does not make sense. If airliners are your standard of safety for space travel, you might as well take a shortcut and just say "don't launch humans into space."

<comment><USER29> _Comparing the two does not make sense. If airliners are your standard of safety for space travel, you might as well take a shortcut and just say "don't launch humans into space."_

It most certainly makes sense. A lot of sense.

The Dragon capsule spectacularly blew itself to smithereens. Now is not the time to bring out some duct tape and baling wire to slap the thing back together so that it can attempt to fly astronauts into space before the end of the year.

Now is the time for careful and considered testing. Not rushing. This thing needs to be safe.

I can guarantee you one thing. If American astronauts die this year because of inadequate testing, that will be the last time you see American astronauts being launched into space on a NASA sponsored platform.

If Americans die because this was rushed, you can kiss NASA's manned space efforts goodbye. We'll pay the Russians what it takes to keep going to ISS. And when ISS ends, NASA will be out of the manned space flight business. The operative word going forward will be "robotics".

<comment><USER6> Space travel is not "safe", period. If you decide to go into space, you should be aware that you're exposing yourself to significant risk. The question is: what risk are you willing to accept?

You may still be right about your prediction, though. But that just says something about people having unrealistic expectations.</comment></comment></comment></comment>


Ask YC:  Why not have "reddit-sense"? (like adsense but adapted to social news) - <AUTHOR>

If the submission rate is too fast, some submissions may not get much of a chance at making the front page.
So why not show new submissions all over the web a la adsense?
The idea is to show new submissions on your site to have your new submissions shown on other sites. <comment><USER2> There's an excellent marketing scheme hidden in there somewhere...</comment>


Google Donates $20,000 to Eclipse Foundation - <AUTHOR> http://www.thepowerbase.com/2012/09/google-donates-20000-to-eclipse-foundation/

<comment><USER2> For those complaining that Google should have donated more, that's just ridiculous. Google already does donate more; they support the Eclipse Foundation financially.

There are performance issues being reported in the latest Eclipse, and it emerged that automated performance tests that used to be run are not currently being run because there aren't machines available. Google steps up - within 48 hours - with more than enough cash to solve the problem.

The problem needed a small amount of resources now, rather than a huge donation in three months time. A bigger donation might not even have solved this problem - obviously there was some resource allocation failure in the first place.

As an Eclipse user, let me say: thank you, Google.

<comment><USER3> From The Fine Article:

"Within 48 hours of Mike's post, a representative of Google's Open Source Programs Office let the developers know they would be taking up his challenge of helping getting the performance tests running again"

That is awesome. Many companies could not get 20k approved for an internal project in that amount of time.

Thank you Google!

</comment></comment><comment><USER4> Note that the $20K was for hardware, not people.

Google also has a few devs pushing code into Eclipse, so it's not like Google's been ignoring them all this time. [http://dash.eclipse.org/dash/commits/web-app/commit-count- lo...](http://dash.eclipse.org/dash/commits/web-app/commit-count-loc.php)

<comment><USER5> The title could have been "Google Donates $20,000 [worth of equipment] to Eclipse Foundation"

</comment></comment><comment><USER6> I ran into the "Juno is ridiculously slow" thing myself (mentioned it just yesterday here: <http://news.ycombinator.com/item?id=4488005>).

Running Juno on my work laptop (a recent ThinkPad i5 system) is close to unusably slow while 3.8 runs great (for a Java UI-heavy app).

Hopefully this helps sort things out (though donating time of Google engineers might be a better practical solution). In any case, I think I'll stick with Sublime Text 2 for Android development when doing anything other than on- device debugging.

<comment><USER7> The community edition of IntelliJ makes a great Android development environment and is free. I can't imagine doing Android dev in a straight text editor.

<comment><USER8> I love IntelliJ, but I keep coming back to Eclipse because of all the plugins available for it. I would love to see IntelliJ somehow build the 3rd-party community of plugin developers.

<comment><USER7> What plugins do you use? Is this for Android?

<comment><USER9> I thought there already is android-sdk integration in IntelliJ

<comment><USER7> There is. It doesn't have all the features of Eclipse for Android but it's everything you need. I haven't touched Eclipse so far.

</comment></comment></comment></comment></comment></comment><comment><USER10> I'm really annoyed with the people looking a gift horse in the mouth in this thread.

<comment><USER11> Eclipse is the primary and recommended dev environment for Android, and it's quite a sluggish beast. This is no gift horse. It's a spoonful of charity where several metric tonnes are called for.

<comment><USER12> Did you read the article? Google donates quite a bit to Eclipse in money and man power. This one time donation was specific to a need for new machines _today_.

</comment></comment></comment><comment><USER8> I am a fan of how much Google has put in Eclipse. I think Google employees are on the Eclipse board, they pay Eclipse committers, and might be one of the bigger contributors to the foundation.

However, I do think that Google (and most companies) should step it up even more. Consider how many employees Google has using Eclipse, and how many products Google has building on Eclipse. They are doing a lot with Eclipse and should contribute a lot.

Yes, Eclipse is open source, and companies do not need to contribute to it. But the benefits of open source is a lot more than the free price, it is the freedom to improve bugs that affect your development, and most importantly the freedom to make sure that some single company is not leading the product/project in a strange direction.

I do think that every company that uses Eclipse as an IDE for its employees should have a moral obligation to donate $500 (the typical price of an IDE) to the Eclipse Foundation. And if you are building a product on top of Eclipse, then perhaps 10% of the $500 per user of your product.

Yes, I know I am asking for a lot. Yes, donating to the foundation does include the full time salaries of committers. Yes, there are more companies than Google that need to be doing this. And, yes, I do fear that the tragedy of the commons is to be expected by default for any successful open source project.

<comment><USER13> As was mentioned in this thread 2 hours ago, Google has 9 committers to Eclipse. [http://dash.eclipse.org/dash/commits/web-app/commit-count- lo...](http://dash.eclipse.org/dash/commits/web-app/commit-count-loc.php) They've also paid members of the foundation for over 6 years. And there is never a moral obligation to pay for something that is explicitly licensed for free.

<comment><USER14> > And there is never a moral obligation to pay for something that is > explicitly licensed for free.

I was with you up until that part. In my opinion there is a moral obligation to donate to projects if you are using them for commercial gain.

</comment></comment></comment><comment><USER15> "a number of users reported significant performance issues when using the 4.2 release, compared to identical setups running the older 3.8"

3.8 is not older than 4.2, they were released together.

<comment><USER16> Well this is the first 4.x release to the general public, compared to the old stable 3.x platform.

</comment></comment><comment><USER17> They should donate a lot more, and actually get them to make a version that is highly optimized for building Android apps. It should be like "Eclipse for Android", rather than just "Eclipse for Java", with an Android development add-on, as it is now.

<comment><USER18> You guys do know we've been paying members of the foundation for going on 6 years or so? This was an additional outlay for some hardware.

<comment><USER19> I think the silent majority understands this. The vocal minority will always complain that _others_ charity isn't enough.

<comment><USER20> Yup, the good 'ol:

Person1: "They should donate so much more that that! God they are such penny- pinchers."

(Person1 donates nothing)

</comment></comment></comment></comment><comment><USER21> So, less than one developer year? That is incredibly generous.

</comment><comment><USER22> eclipse is ridiculously slow IDE. Let me change letters for you: DIE.

</comment><comment><USER23> $20K? just 20K. :(

</comment><comment><USER24> Woah 20k$ I mean it's like .... Like ... Ridiculous !

</comment><comment><USER25> 20K is too less coming from Google. They have thousands of developers benefiting from the ide and Android + Google tools use eclipse as well.

<comment><USER4> I'd be very surprised if there weren't at least a few Eclipse committers inside Google.

EDIT: In fact, they have nine. [http://dash.eclipse.org/dash/commits/web- app/commit-count-lo...](http://dash.eclipse.org/dash/commits/web-app/commit- count-loc.php)</comment></comment>


Animated line drawing using SVG - <AUTHOR> http://jakearchibald.com/2013/animated-line-drawing-svg/

<comment><USER2> Writing drawing code like this by hand is really tedious and even though a lot of vector drawing apps output SVG code, it is usually quite complicated and ugly.

We make a vector drawing app called WebCode that instantly generates nice and readable SVG and JavaScript+Canvas code.

[http://www.webcodeapp.com/](http://www.webcodeapp.com/)</comment>


Extreme Programming Explained - <AUTHOR> http://www.yosefk.com/blog/extreme-programming-explained.html

<comment><USER4> > The permanent brain damage of that CMM training course makes me admire XP.

OK. This article espouses XP as a religion. What irritates me is that implies an all-or-nothing approach of XP. You want floormats with that car? Pair programming with iterations etc. Which can be too much to handle - <USER2> adopting some of the XP principles and practices can make a big difference - stand-up meetings for example. I worked on a project that just started having stand-up meetings - to replace the once-weekly meeting where we would all either just fume at each other or silently say nothing. Communication improved to a point where we realized there was _no_ real communication going on before (e.g. this is how I _feel_ with X task)

That being said. Is Agile better? I don't know. I'm working on an Agile project right now - I hate the burndowns, hate them with a passion - <USER3> your accountability to a number. But what it does - updating burndowns is it makes your progress transparent - to you as well as the other people on the team.

<comment><USER5> Haha, as a PM I've found engineers hate burndowns with an absolute passion. And so do I. But you're right - the transparency makes it worth it. I try to make sure I gather the data in an unobtrusive manner as possible, and keep irritating meetings to a minimum. No matter what I do it still gives people the irrits. Having worked as a software engineer, I wish some of them would work as a PM for a bit to know what we go through as well...

</comment></comment><comment><USER6> XP is a specialized tool for getting specialized results. As the article mentioned, it is good for getting large volumes of average code. (And likely doing so with fewer mistakes).

We XP for the same reason we have 2 pilots on an airliner. Its long and boring but messing up can be very bad. So we send 2 people to manage the drudgery, keep each other motivated and catch mistakes that could lead to problems later.

The virtue of the lone expert however, applies to a very different type of problem. He has to be free to try the most wild outlandish things that pop into his head. This is not possible in a "pair programming" environment. There is astonishingly little difference between design flaw and brilliant innovation in this space.

When we test the X-1 we send Chuck Yeager not a pair of pilots from Delta.

</comment><comment><USER7> He hits the nail on the head with this article - XP is a methodology for large groups of average programmers to write large volumes of average code. This is not necessarily a bad thing; that is the requirement of most large organizations. Most corporate software is just forms and reports in front of a database; there's nothing _algorithmic_ in there that necessitates deep concentration. It doesn't matter how big the codebase is. That's why XP doesn't care about ownership of code, or the "social" aspects breaking concentration.

But XP is simply not suitable for real "extreme programming", i.e. small teams producing novel products. There is a BIG difference between "specs that change because a business user can't make up their mind" and "specs that change because we are writing a program that has never been written before" which completely escapes XP people.

<comment><USER8> I'm no XP fan, but this comment is ignorant. It's entirely possible for two people to concentrate together on a hard problem, and when it works well you get a "two heads are better than one" effect. It matters a lot how big the codebase is on _any_ software project (and XP is well aware of this). Collective code ownership is advocated for a number of good reasons, such as that it mitigates risk and increases quality (think open source). The vast majority of "large groups of average programmers" are not doing XP and would hate the idea of it just as much as you do, and for some of the same reasons. Plenty of XP projects have above-average programmers. (Edit: Oh, and by the way, when I was paying attention to this stuff the corporate types were the source of greatest _resistance_ to XP, while most of the people advocating it were technical. So it's a little rich to hear XP described as a corporate conspiracy to impose a drone state on creative programmers. Perhaps it's changed since then.)

XP provokes a lot of one-sided emotional reactions from people, some in favor, most against. (I'd include the OP in this.) In fact, I've noticed that some of the most cultish XP people turn out to have been the ones who had knee-jerk negative reactions at first. Once they decide they don't want to sit in a room by themselves all day after all they flip one bit to the other and become evangelists of the opposite. The irony is that much of what they say both pre- and post-koolaid is actually true. But it gets spoiled by rigidity.

<comment><USER7> But you don't need compulsory socialization to do that! All you need is a colleagues who you talk to from time to time. What if the person who knows exactly how to do what you want to do is someone elses XP buddy? Now you have two people stalled instead of just one.

There is ample evidence that "ownership" of code results in better quality and a more motivated workforce. People like seeing a feature from inception to completion. So long as basic conventions are adhered to, there's no need for anyone to touch anyone elses code except in a genuine emergency.

Can you point to any open source project that is actually collectively owned? I think not, everything actually has an owner who gets to say who gets to commit what...

<comment><USER4> > Can you point to any open source project that is actually collectively > owned?

Collective ownership - maybe more like republican ownership - see the code_swarm videos - only a cluster of people commit.

Successful open source projects are led by very strong leaders: (Linux) Torvalds, (Ruby on Rails) DHH, (Gnome/Mono) De Icaza. Eclipse is questionable - it's more like run by a board of directors, with a large (mostly IBM) programmer workforce.

> But you don't need compulsory socialization to do that!

Agreed. We got past the teamwork learning curve and we pair when we have to get things done fast/fix a problem. We usually don't pair otherwise, unless you count long-running IM conversation threads as pairing.

> XP provokes a lot of one-sided emotional reactions from people, some in > favor, most against.

As for emotional reaction, I still get a heebie-jeebie hokey feeling when someone says "I'll drive" [but only in reference to pair programming].

As an aside, pair programming does not work in a dom-sub relationship (especially when the sub is passive and doesn't want to code) - the dom will take over the coding.

</comment></comment></comment></comment><comment><USER8> XP does have a social bias. Eric Evans once suggested "social programming" as a more accurate name for it. When combined with the formulaic nature of software "process" (do these 12 things, code must be written in pairs, etc.) this aspect can turn weird or even cultlike. That's unfortunate because the best and most fun software projects are indeed (in my experience) highly collaborative. But compulsory socialization isn't fun at all.

</comment><comment><USER5> As much as XP has its flaws, I don't think it deserved the smackdown it got in this article, which was somewhat biased.

Also what was with the bizarre, idiomatic, confrontational writing style?

<comment><USER7> You've not read a personal blog before then?</comment></comment>


China's Ghost Cities Aren't Exactly Dead - <AUTHOR> http://www.whatsonweibo.com/chinese-ghost-cities-coming-to-life/ <comment><USER2> China is bringing up new cities in an organized fashion. First the infrastructure, roads, plumbing and power goes in. Then the buildings go up. Then the stores are stocked and staffed and the transportation system started up. Then people move in and businesses are moved in.

This costs much less and is less disruptive than doing it one building at a time in a busy city. Building is really cheap when you can do it in bulk with nothing to get in the way.

Shanghai has a population of 14 million. Beijing is at 11 million. The government is trying to spread things out a bit.

</comment><comment><USER3> Url changed from [http://motherboard.vice.com/read/chinas-ghost-cities- arent-e...](http://motherboard.vice.com/read/chinas-ghost-cities-arent- exactly-dead), which points to this.</comment>


Can we colonize the moon? - <AUTHOR> http://www.csmonitor.com/Science/2015/0722/Can-we-colonize-the-moon <comment><USER3> There's a great speculative scifi book called "Welcome to Moonbase" (Ben Bova, 1987)[0] that is written as an employee manual for people relocating to an established moon colony. There are sections on the history of the moonbase, the economy, the social aspects, living and working on the moon. It's a fantastic paleofuture read, and is one of the books that kindled my love for sci-fi and space exploration as a kid. It's fiction, but does make it seem like living on the moon is something achievable within our lifetimes and could serve to answer the question "can we colonize the moon?".

[0] [http://www.amazon.com/Welcome-Moonbase-Ben- Bova/dp/034532859...](http://www.amazon.com/Welcome-Moonbase-Ben- Bova/dp/0345328590)

<comment><USER4> The Moon is a Harsh Mistress is also one great scifi classic Although more later stage living on the moon and revolution.

[http://www.amazon.com/The-Moon-Is-Harsh- Mistress/dp/03128635...](http://www.amazon.com/The-Moon-Is-Harsh- Mistress/dp/0312863551)

<comment><USER5> I read that book twice. Once with the german title "Der Mond is eine herbe Geliebte" (direct translation), then years later a friend recommended the book "Revolte auf Luna" ("Riot on Luna"). I got half way through the book before I realized that I was reading the exact same book. Great story nevertheless.

</comment></comment></comment><comment><USER6> A similar proposal from a while back was one on "Rapid Bootstrapping of Space Industry," essentially concluding we could have a robust space industry with an industrial output 1,000,000x that of US GDP within about four decades - <USER2> as little as 12 metric tons landed on the moon to kickstart the process. The proposal relied heavily on automated systems and coming advances in robotics, but ignored other likely improvements such as atomic-scale manufacturing. Other than perhaps sheer disbelief I'm not sure why there hasn't been more interest in it.

[1] [http://www.philipmetzger.com/blog/affordable-rapid- bootstrap...](http://www.philipmetzger.com/blog/affordable-rapid- bootstrapping-space-industry-solar-system-civilization/)

[2] Paper - [http://www.philipmetzger.com/blog/wp- content/uploads/2014/09...](http://www.philipmetzger.com/blog/wp- content/uploads/2014/09/Preprint_Affordable-bootstrapping-of-space-industry- and-solar-system-civilization.pdf)

<comment><USER7> From that paper: _" A 1980 summer study at the NASA Ames Research Center (Freitas and Gilbreath 1980) showed that self-reproducing machines are theoretically possible."_

I remember that crowd. They wanted to have self-reproducing machines on the moon by 2000. I asked, "how soon can you do it in New Mexico". They didn't like that.

<comment><USER6> The proposal in the paper is at least somewhat different: it wouldn't become fully self-sufficient until the later stages of about a seven stage process. The earlier stages just involve unmanned robots controlled from Earth, beginning with around 17th century technology and moving towards autonomy with each successive generation. I definitely see your point, but this isn't quite the same as proposing a lunar colony of self-reproducing robots within the next few years (besides, robotics have come a long way since then).

</comment></comment></comment><comment><USER8> "Colonize" isn't the right word. Living on another planet doesn't make any sense for us. Perhaps it makes sense to put a very small number of people on the moon for purely scientific or commercial reasons - but it might make more commercial sense to instead use robots and sidestep the hassle of maintaining real live humans up there.

Charles Stross wrote about this a few years ago [1]:

> Whichever way you cut it, sending a single tourist to the moon is going to > cost not less than $50,000 — and a more realistic figure, for a mature > reusable, cheap, rocket-based lunar transport cycle is more like $1M. And > that's before you factor in the price of bringing them back ...

> The moon is about 1.3 light seconds away. If we want to go panning the > (metaphorical) rivers for gold, we'd do better to send teleoperator- > controlled robots; it's close enough that we can control them directly, and > far enough away that the cost of transporting food and creature comforts for > human explorers is astronomical. There probably _are_ niches for human > workers on a moon base, but only until our robot technologies are somewhat > more mature than they are today; Mission Control would be a lot happier with > a pair of hands and a high-def camera that doesn't talk back and doesn't > need to go to the toilet or take naps.

[...]

> When we look at the rest of the solar system, the picture is even bleaker. > Mars is ... well, the phrase "tourist resort" springs to mind, and is > promptly filed in the same corner as "Gobi desert". As Bruce Sterling has > puts it: "I'll believe in people settling Mars at about the same time I see > people settling the Gobi Desert. The Gobi Desert is about a thousand times > as hospitable as Mars and five hundred times cheaper and easier to reach. > Nobody ever writes "Gobi Desert Opera" because, well, it's just kind of > plonkingly obvious that there's no good reason to go there and live. It's > ugly, it's inhospitable and there's no way to make it pay. Mars is just the > same, really. We just romanticize it because it's so hard to reach." In > other words, going there to explore is fine and dandy — our robots are all > over it already. But as a desirable residential neighbourhood it has some > shortcomings, starting with the slight lack of breathable air and the sub- > Antarctic nighttime temperatures and the Mach 0.5 dust storms, and working > down from there.

[1] [http://www.antipope.org/charlie/blog- static/2007/06/the_high...](http://www.antipope.org/charlie/blog- static/2007/06/the_high_frontier_redux.html)

<comment><USER9> > Living on another planet doesn't make any sense for us

At some point in the future Earth will be uninhabitable for humans. At that point, it will make plenty of sense.

> sending a single tourist to the moon...

All this focus on tourists seems like a strawman. Yes, there are people who would probably want to go to the Moon or Mars for a space-cation. No, that is not a primary reason for the existence of space programs.

Manned Moon and hypothetical manned Mars missions are not the endgame. They're stepping stones that hopefully lead to our escape from the solar system.

<comment><USER10> > At some point in the future Earth will be uninhabitable for humans. At that > point, it will make plenty of sense

Are you suggesting humans will damage the planet that much?

I find it difficult to imagine we can damage the Earth to such a degree that is is easier to try and settle Mars than undo the damage on Earth.

I want manned outposts on Mars as the next person. I like to think that the challenge of doing it is enough justification to undertake such an endeavour.

<comment><USER11> Well, if "some point in the future" is taken liberally enough, then at "some point in the future" the Sun will be a red giant whose radius is greater than Earth's orbital radius. Earth is getting destroyed in about 5-6 billion years no matter what we do.

Of course, if that's what you're planning for, the much more sensible plan is to wait for about a billion years, and see if either A) Technology has made this cheaper or B) We've already died for some other reason.

</comment></comment></comment></comment><comment><USER12> > Harvesting the vast amounts of water on the Moon – the equivalent of the > Great Salt Lake in Utah – could make the project commercially viable.

I didn't know this. But anyway, I live by the Great Salt Lake, and it's more like the Great Salt Puddle. Would that amount of water really sustain a colony? I suppose the base would have the most efficient water facilities ever invented, but still, it wouldn't last for long unless the water was recycled forever.

(I see, later, they refer to finding such ice as 'prospecting for gold' \- I'm optimistic about our future in space, but this water situation is tricky. Ship it up there, maybe?)

<comment><USER13> Water is _heavy_. A SpaceX Falcon-heavy has a maximum capacity of 21,200kg to transfer orbit - that's not going to go very far in a colony even if it's all water. Shipping it up there is really not an option.

Unless you have a space elevator...

<comment><USER14> Would it make sense to harvest asteroids for water and bring it to the moon?

I am thinking about just one spaceship which could go back and forth between some asteroid and a moon orbit. It shoots the water down to the moon, so that it does not even have to touch-down and take-off again. How much energy would be needed for such a mission? Probably it would be a very complex mission to get right, but once it is established you might have water for free on the moon.

<comment><USER15> No!

Colonizing the Moon only makes sense if the water is there. If we're going to harvest water from asteroids, we should colonize them instead.

</comment></comment></comment></comment><comment><USER16> I thought the Outer Space Treaty was meant to prevent things like these. Personally, I hope we'll leave behind all of our arbitrary notions of states once we leave earth. It's too late to remove the dividing lines on earth, but we still have a shot at idealism in space.

<comment><USER17> The Outer Space Treaty prevents people/governments from owning land outside of Earth but it gives organizations the right to keep others out of places they are currently using, which comes to much the same thing. Now, the Moon Treaty does what you want but that was never ratified by anybody with a serious space program.

</comment></comment><comment><USER18> Will a commercial enterprise see people as a needless expense that hurts their bottom line? Why cant robots mine the moon withiut us?

</comment><comment><USER19> "We are so concerned with if we could, we didn't stop to consider if we should."

</comment><comment><USER20> Wouldn't radiation and meteorites be a huge concern?

</comment><comment><USER21> Uuuh... I thought the gravity on the moon will deform human skeletons, as they are "made" for human gravity, so that makes living anywhere that has different _g_ impossible. Is that not true?

<comment><USER22> Then maybe in the long run they would need to build a base that rotates rapidly and simulates a gravity of g at the perimeter by centrifugal force.

<comment><USER23> Or more simply just wear weights distributed across your clothes?

<comment><USER22> Well maybe that works against the bone structure changes. On the other hand gravity (or the lack of it) has other effects too on the human body[1]. One needs to use body forces to compensate the lack of gravity. Contact forces won't help here.

[1] [https://en.wikipedia.org/wiki/Effect_of_spaceflight_on_the_h...](https://en.wikipedia.org/wiki/Effect_of_spaceflight_on_the_human_body#Fluid_redistribution)</comment></comment></comment></comment>