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NASA Study Proposes Airships, Cloud Cities For Venus Exploration

Ihlosi Re:As with all space missions: (200 comments)

In learning school, the people of my tribe were taught that molecules ARE matter.

Atomic nuclei are matter. Disassembling and reassembling atomic nuclei, however, is an entirely different beast (several orders of magnitude difference in energy) than disassembling and reassembling molecules.

2 days ago
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NASA Study Proposes Airships, Cloud Cities For Venus Exploration

Ihlosi Re:As with all space missions: (200 comments)

I love the space elevator/beanstalk idea, but we're several human generations away from the first full-scale model.

Which is why we should stop dreaming about it and stark working on things that are feasible with our technology. Mass drivers, launch loops, laser propulsion, you name it.

Venus won't be of much use until we can disassemble and reassemble matter itself.

Actually, we don't need anything that exotic (matter generation) for starters. We need a universal chemical synthesizer, which can assemble chosen molecules from a set of given input compounds. Basically a very flexible chemical plant. It doesn't need to create matter, just rearrange given molecules into new molecules.

about a week ago
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NASA Study Proposes Airships, Cloud Cities For Venus Exploration

Ihlosi Depends on where in the atmosphere you are. (200 comments)

I thought Venus' atmosphere was corrosive?

Some parts of it are. The higher your altitude, the less sulphuric acid you'll find.

about a week ago
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NASA Study Proposes Airships, Cloud Cities For Venus Exploration

Ihlosi Re:As with all space missions: (200 comments)

After Luna and Mercury, there will be very little use of the other planets, other than small moons.

I disagree.

Planets are just too darn hard to get on and off of.

Only if you use primitive launch technologies which require the ascent vehicle to carry all of the necessary energy and reaction mass for the ascent.

Seriously, you think that in your scenario, we'll still use rockets as the main way to get off planets?

The first thing we need is one or more ways to launch things into space where most of the energy and reaction mass is not carried by the launch vehicle.

None have proper gravity or pressure for us.

Venus could be cooled down with a solar shade in space (which could double as a power plant) and be transformed into something more habitable than its current state.

Also, some applications work in a wide range of gravity. You can have fairly normal kitchens, bathrooms, swimming pools, showers, sinks and toilets on Mars, despite only having a third of the gravity of Earth.

about a week ago
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NASA Study Proposes Airships, Cloud Cities For Venus Exploration

Ihlosi Re:Solar irradiance in the article? (200 comments)

Why did you make the parent comment specifically stating the opposite?

Err, I didnt?

The correct relationship is an inverse-square-distance (1/(d^2)) relationship. Compared to Venus, Earth is about 140% of Venus' orbital radius from the sun (and therefore gets 1.4^2 the solar irradiance) and Mars is about 240% farther from the sun (and therefore gets 2.4^2 the solar irradiance).

The numbers in the article give an inverse (not squared) relationship, which would be correct for distances, but not for solar irradiance.

about a week ago
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NASA Study Proposes Airships, Cloud Cities For Venus Exploration

Ihlosi Re:Solar irradiance in the article? (200 comments)

Different magnetic fields strengths and atmospheres (or lack thereof).

Photons shouldn't be affected by magnetic fields. And the numbers given in the article correspond suspiciously well to an inverse-distance relationship.

about a week ago
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NASA Study Proposes Airships, Cloud Cities For Venus Exploration

Ihlosi Re:Awesome! (200 comments)

I've been wondering for years why we couldn't send a dirigible probe to Venus

Balloons are neither dirigbles, nor dirigible. They just provide buoyancy.

about a week ago
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NASA Study Proposes Airships, Cloud Cities For Venus Exploration

Ihlosi Re:As with all space missions: (200 comments)

We're not talking about an air ship where you can take a leisurely stroll on the pool deck admiring the Venetian sunset. We're talking about a space ship that is suspended in a convection stove.

Or a sauna. On the plus side, you get plenty of solar power to run your AC with.

about a week ago
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NASA Study Proposes Airships, Cloud Cities For Venus Exploration

Ihlosi Solar irradiance in the article? (200 comments)

The article states that Venus gets 40% more solar irradiance than Earth and 240% more than Mars. I wonder where these numbers come from. From the inverse-square law, Venus would get about twice the solar irradiance of Earth, and about four times the irradiance of Mars ...

about a week ago
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NASA Study Proposes Airships, Cloud Cities For Venus Exploration

Ihlosi Let's do it. (200 comments)

The airship idea is a great idea. Not with astronauts (there wouldn't be much to do for them, unlike on Mars, where they could look at rock formations, dig holes and play golf), but a robotic airship would get a much closer look at Venus than any satellite.

Plus, it would be a "first".

about a week ago
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How Relevant is C in 2014?

Ihlosi Re:C is very relevant in 2014, (641 comments)

Hmm... upon reading my comment, I realize that C *IS* guides

C doesn't really guard anything. It does keep you from having to roll your own multiword arithmetics or integer division algorithms, and from dealing with architecture-related things that are mind-boggling for a human, but just another set of rules to a compilers (pipelines, delayed instructions, etc.), and takes over things like optimizing register usage.

On a computer, all the guides come at the cost of performance. Sure, you can make a programming langugage where buffer overflows are alway caught, but that language will spend a lot of CPU cycles on checks.

about two weeks ago
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How Relevant is C in 2014?

Ihlosi Re:Very relevent for small target embedded stuff. (641 comments)

BS. Embedded development still happens on 8-bit controllers

And there's also plenty of ARM chips that don't run Linux (because they can't due to lack of a MMU), e.g. Cortex-M0...M4-based parts.

That's one of the nice things about small target embedded work. It covers everything from 8-bit to 32-bit, from simple (no hardware multiplier, no division in hardware) to loaded (hardware floating point support, MAC units, HW dividers), from slow (temperature logging) to fast (control loop running at 30 kHz requiring 3us latency).

about two weeks ago
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How Relevant is C in 2014?

Ihlosi Re:Very relevent for small target embedded stuff. (641 comments)

I found that compared to having separate files for functions in assembly (that are then called from C), inline assembly is usually more hassle- and bug-prone.

about two weeks ago
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How Relevant is C in 2014?

Ihlosi Re:C is relevant because it is low level. (641 comments)

C is important because it directly presents the actual machine memory model.

Well, not really. There are some architectures that were basically designed to be used with C (68k, ARM), but there are others (8051) where a C compiler need to jump through some major hoops.

And the C compiler still shields the programmers from things like stack frames or worrying about CPU register allocation.

about two weeks ago
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How Relevant is C in 2014?

Ihlosi Small target! (641 comments)

Depends mostly on compiler and toolchain availability on those platforms.

To clarify: "Small target" means memory (RAM/Flash) is measured in kB, sometimes even in bytes.

You still have Python-capable processors for embedded systems if you can't afford to learn C.

As far as target size goes, that thing does not qualify as "small target".

FWIW, I've been struggling with LPC4300 series processors.

Those chips look like they're on the large end of "small target". Cortex-M4s are already pretty beefy CPUs.

The open source toolchain is just so bad that your CPU hard faults on first attempted function call (most likely due to incorrect memory maps).

You can usually get pretty detailed reasons for a hard fault if you dig into the appropriate CPU registers (HFSR, etc).

I'd check the linker command file. Setting up a basic memory map isn't that hard - it's the not-so-basic stuff where things get interesting (copying functions to RAM for execution, etc).

about two weeks ago
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Montana Lawmakers Propose 85 Mph Speed Limit On Interstates

Ihlosi Re:Attn: Scott Sales: (525 comments)

And no fucking cops, either.

Not getting the TSA/DHS/ZXY treatment at the airport is worth a few hours of driving.

about three weeks ago
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Montana Lawmakers Propose 85 Mph Speed Limit On Interstates

Ihlosi Re:Save an hour (525 comments)

Sure he would save an hour, and he would probably also burn a lot more gas.

He was working for an oil company. Burning more gas means more profit for oil companies.

about three weeks ago
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Football Concussion Lawsuits Start To Hit High Schools

Ihlosi Re:Value your prefrontal cortex? (233 comments)

Football wasn't always played in full body armor.Perhaps it's time to redesign based on a scientific understanding of the risks and how to mitigate them.

It's actually very simple. The brain is soft. The skull is hard. When the two collide due to the head experiencing too much acceleration, it's easy to guess which of the two will be damaged more.

The are dozens of types of sport that don't involve the participants head and neck experiencing large forces as a normal part of the game.

about three weeks ago

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