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Comment: Re:Hobbit (Score 1) 192

by Rei (#49783411) Attached to: How To Die On Mars

Well, certainly more realistic than living on the surface. And probably easier to set up than a Mars habitat - terrain is irrelevant and your entry is so much easier - plus, even normal Earth air is a lifting gas on Venus. And it'd be no less self-sustaining (that is, to say, "not very" ;) ).

There's no need to send people offworld to do science, whether to Venus or Mars. But while there's no need for any kind of "facility" at all, manned or otherwise, for robotic equipment on Mars, the concept of some sort of floating "facility" on Venus is pretty important. Any sort of craft designed to tolerate Venus's surface environment is going to make a terrible analysis lab or sample return vehicle. I mean, even solar panels would have to be heavily shielded on a sampling run to not be destroyed; there's very little that you can have exposed that can tolerate that environment. Sampling and analysis or return on Venus is best done in two stages: 1) Buoyant craft that repeatedly dive and rise the atmosphere like submarines and take samples on the surface, and 2) a floating platform containing any analysis equipment or return hardware, high gain communication with Earth, and solar panels to recharge the batteries of the sampling craft while samples are being offloaded.

Venus's surface is really unusual and it'd be neat to know more about what's there. I'm still not big on the concept that we need humans there to do it, but at least a floating platform of some kind would be important. The only advantages I could see for having humans would be to cut the communications latency with the samplers to allow for smarter sampling decisions without requiring them to wait in the harsh environment for round-trip communications on Earth, the ability to repair samplers, and perhaps mildly better local analysis of samples and/or decisions about what to bring back. Hard to justify the added price tag, though.

Comment: Re:Hobbit (Score 1) 192

by Rei (#49782957) Attached to: How To Die On Mars

"Never" is too harsh of a word. But I share in your frustration about their glossing over the reality of engineering these "simple" processes that they envision. Just the amount of engineering work to *design* with enough precision to actually build a fully self-sustaining industrial base designed to work on Mars with the individual components being small enough to plausibly launch would cost in hundreds of billions to trillions of dollars Everything in industry has unimaginably massively long dependency chains that interconnect with each other, using raw materials sourced from a massive variety of different types of geological formations the planet over. You basically have to reengineer all industry on Earth for the martian envirionment in a gigantic mass-minimization optimization problem. You can't just plop down a 3d printer and some generic "mining robot" that roams around your habitat like people envision in their sci-fi fantasies. Reality isn't so friendly.

Even worse, if you start launching stuff without doing all of that engineering work, you end up heading down a dead end. Let's say you make some smelter that takes limonite as its iron feedstock. But then as you start expanding your industrial base, you discover that you actually need a lot of sulfuric acid, and your iron production process should instead be designed to work around iron sulfate feedstocks with sulfuric acid produced as the much-needed byproduct, with a different type of smelter required. Well, guess what? That smelter that you spend $20 billion dollars engineering, building, and shipping to Mars is now scrap. It applies to almost everything. You made a pipeline out of polyethylene? Whoops, now you discover that you sometimes need to ship corrosive liquids and it really should have been made out of teflon, tough luck! Built some big piece of industrial equipment that relies on high-temperature inconel alloys? Whoops, you discover that you can't find a practical niobium deposit within driving distances, you have to reengineer your hardware for very different matierial properties or operating environments! Everything down to the tolerances on your bolts or the type of plastic you put on your greenhouses can be a costly screwup if you don't design your whole industrial layout in advance on a standardized set of hardware and know precisely what mineral deposits are where and how to get at them.

To all of the sci-fi buffs: It's not time to try to colonize Mars. It's time to learn about Mars, and to engineer here on Earth. And it's going to be in that phase for a long, long time. Want to go to Mars and hop around for a bit with a rock hammer like they did on the moon? Fine. But don't call it a colony.

Comment: trees cut down in the cities (Score 4, Insightful) 59

by lkcl (#49782843) Attached to: Heat Wave Kills More Than 1,100 In India

i visited bangalore in 2006, to see a friend living there. he explained that when the trees were cut down in the cities (so that more housing could be built), temperatures soared by an additional 10 *centigrade*. so, the ambient temperature surrounding the cities would be 45 degrees, but in bangalore it would reach *fifty five* centigrade. the point of mentioning this is that it's a much more direct version of how man has an effect on his immediate environment. change the landscape, you change the weather, it's as simple as that. we can learn from that... or simply die. it's our choice.

Comment: Re:I am amazed (Score 3) 113

by Rei (#49782699) Attached to: A Text Message Can Crash An iPhone and Force It To Reboot

It's not that NSString itself is broken, it's that the fact that 99.99% of the time an NSString is one 16-bit code unit per glyph that apps using it rarely test the use case where it's two code units per glyph. So a person goes in and writes an app that inserts a new character at a particular byte offset and it works 99.99% of the time, but if it happens to get stuck in the middle of a multi-code-unit glyph, the program breaks.

The documentation is no help. First off, it lies:

Conceptually, a CFString object represents an array of Unicode characters (UniChar) along with a count of the number of characters. The [Unicode] standard defines a universal, uniform encoding scheme that is 16 bits per character.

As we all should know, that's simply not true. Unfortunately, a lot of people don't know better. Unicode is not a universal, uniform encoding scheme that is 16 bits per character. Even UTF-16 isn't that.

A string object presents itself as an array of Unicode characters . You can determine how many characters a string object contains with the length method and can retrieve a specific character with the characterAtIndex: method. These two “primitive” methods provide basic access to a string object.

characterAtIndex returns a 16-bit integer. So obviously it has no way to actually represent wider unicode characters. The length method is not the number of characters on the screen, but the number of code units, which is different, but highly misleading to programmers. They're, again, the same thing 99.99% of the time, but those rare cases where they're not generally slip through testing. And this is why UTF-16 is such a hazardous encoding to use.

Yes, NSString is old. And that's part of the problem. It was made at a time where many thought that unicode was only going to be 16 bits. It hasn't aged well. And it's caused a lot of bugs over its time. And now I'd bet that it or something similar has created a brand new iPhone-equivalent of Winnuke.

Programmers really need two types of strings, and only two, for the lion's share of tasks. One, binary strings, where a char is always 8 bytes and operations can be optimized to heck and back. And two, unicode strings, where a char always represents a whole unicode character that you would display, and the count of characters represents the count of display characters and so forth. None of this "99.99% of the time it's one thing, but every so often it's another...". That's asking for bugs.

Comment: Re:Time to buy some SpaceX stocks....oh wait... (Score 1) 35

by Rei (#49782511) Attached to: SpaceX Cleared For US Military Launches

Yep.. and the etymologies are totally unrelated. "Foul" is believed to possibly trace back back to an onomatopoeic word "*pu", meaning foul or rotten, being the sound a person makes when smelling such an object (*p underwent an early shift to f). "Fowl" and "fly" are both believed to trace back to "*pleuk", meaning to fly. The proto-germanic for bird, fuglaz, could be thought of as "that which flies". There are lots of cognates in modern languages - for example, in Icelandic, "u" often equates to an "ow" sound in English, and "gl" to a "wl" sound (aka, closer to Old English than modern). So the Icelandic "fugl" (bird) equates "fugel" in Old English and "fowl" in modern English. Other examples are ugl(a) -> owl, hund(ur) -> hound, turn -> tower, bund(inn) -> bound, and even sund->sound (in both cases, in the context of "a large body of water connected to the ocean", like "Puget Sound").

Obligatory.

Comment: Context (Score 2) 35

by Bruce Perens (#49782349) Attached to: SpaceX Cleared For US Military Launches

This ends a situation in which two companies that would otherwise have been competitive bidders decided that it would cost them less to be a monopoly, and created their own cartel. Since they were a sole provider, they persuaded the government to pay them a Billion dollars a year simply so that they would retain the capability to manufacture rockets to government requirements.

Yes, there will be at least that Billion in savings and SpaceX so far seems more than competitive with the prices United Launch Alliance was charging. There will be other bidders eventually, as well.

Comment: Re:Hobbit (Score 1) 192

by Rei (#49782033) Attached to: How To Die On Mars

Oh wait someone invented a thing called a submarine and developed the means to heat, pressurize and provide oxygen and fresh water to people living inside of it.

And submarines are about as far from self-sufficient as possible, relying entirely on their shore support infrastructure to supply everything except oxygen and water. Every last part onboard the ship, every last meal they eat, comes from shore. You know, just like it will be with a Martian colony. Oh sure, fantasists in the early days of submarines dreamed of them being like underwater colonies and raising their own food and having their own internal industry to make all their replacement parts and so forth, just like people do today about Martian colonies. The reality turned out to be... well, less fantastical.

(I love how you can just gloss over something as complex as an O2-and-water-producing Mars-environment-operating nuclear reactor as if it's just some trivial thing to design, make, launch, and keep operating ;) )

Comment: Re:I am amazed (Score 3, Informative) 113

by Rei (#49781853) Attached to: A Text Message Can Crash An iPhone and Force It To Reboot

I'd be willing to bet that the unicode library they were using was UTF-16 . Either that or they were handling unicode in a straight binary string with something homebrewed. Both are horribly dangerous - the latter for obvious reasons, but the former in particular because it makes it easy to code something that "just works" for 99,99% of cases, but those rare 0,01% side cases involving 32-bit unicode characters slip through testing and come back and bite you down the road. It's amazing how many apps have incorrect behavior with 4-byte unicode characters, on a wide range of platforms.

Both should be considered bad practice and programming languages evolved to standardize on UTF-8 for any string format that is to handle unicode. C++ for example needs to introduce something along the lines of "std::ustring" that makes unicode string ops "just work" with a UTF-8 backend, at the cost of some memory and performance vs. std::string, which should be seen as exclusively for ascii and binary string operations. std::wstring should be obsoleted.

Comment: Re:Showing once again how worthless insurance is (Score 1) 84

A) Insurance NEVER pays to replace a car, even if it is totaled. They give you 80% of the current value.

B) I have 40K to replace MY car which the other guy totaled but which HIS insurance won't pay anything near what it costs me. I could sue him in court for damages to recover the rest of the money but insurance companies have seen to it that you really can't sue in court any more because they would have to do what people are paying them to do.

C) Your donation of a kidney is your choice. That is completely different than someone plowing into me which has happened with every car I have every owned. Mainly as I'm the last guy in line.

Comment: Re:Hobbit (Score 0) 192

by Rei (#49781503) Attached to: How To Die On Mars

Let go of your anger, young padawan.

Nowhere did I say that it exists today. I didn't even say it'd be the best option - my post was about how even that "simpler" approach is still incredibly expensive and complex.

Please aim your rage in the correct direction.

(and FYI, even NASA uses the word "hab" - for example, their X-Hab competition.)

Comment: Showing once again how worthless insurance is (Score 1, Interesting) 84

Insurance is the biggest scam ever perpetrated in the history of mankind. You pay and pay and pay some more, then, when you need to use it you're given every excuse possible why the coverage you've been paying for doesn't apply.

When one takes into consideration the thousands of dollars each year the average person pours down the drain for insurance, it's no wonder people are going broke. That money could be used for more productive endeavors such as food, housing, education or transportation.

Instead, the money is lost in the ether, used only to enrich a few while the many bleed from a thousand cuts.

Comment: Re:Terraforming potential? (Score 2) 192

by Rei (#49781309) Attached to: How To Die On Mars

My favorite approach is to build floating solar towers on Venus or the gas giants - big chunks of greenhouse material shaped like an inverted funnel reaching out into space. Unable to radiate its IR radiation back to space, the air under the funnel would become hotter than the surrounding atmosphere and rise (imparting lift to the funnel without even requiring a lifting gas). Due to the size, drag against the funnel surface would be irrelevantly small. As the funnel narrows, the gas velocity would increase - with a large enough funnel, to well over escape velocity. The funnel could be moved and aimed to some degree by directing part of the flow out through adjustable side jets. If the funnel was shaped so as to cause the gases to spiral and then flare out at the end, you could centrifugally sort the gases out by atomic mass, and thus for example rob light gases (such as water and nitrogen) of escape velocity while allowing heavy gases like CO2 the energy to escape.

Venus could send CO2 on a Mars intercept trajectory to raise its temperature and pressure. Jupiter could send hydrogen on Venus and Mars intercept trajectories, for Bosch water generation. Large moons and dwarf planets could be similarly seeded.

Of course, the obvious question: will this, or any other form of terraforming begin any time in the next many-hundred years?

Nope.

Comment: Re:Radiation not a problem, an opportunity (Score 1) 192

by Rei (#49781239) Attached to: How To Die On Mars

The sad fact is, the first colonies will probably be build right out in the open on flat land with nothing around for dozens of kilometers, because it's safer to land there. Which is why we haven't landed any Mars probes in deep canyons or the like, despite all of the interesting geological formations that would be exposed on the walls.

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