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Comment: Re:As with all space missions: (Score 1) 200

by Ihlosi (#48658665) Attached to: NASA Study Proposes Airships, Cloud Cities For Venus Exploration
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.

Comment: Re:As with all space missions: (Score 1) 200

by Ihlosi (#48635763) Attached to: NASA Study Proposes Airships, Cloud Cities For Venus Exploration
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.

Comment: Re:As with all space missions: (Score 1) 200

by Ihlosi (#48624419) Attached to: NASA Study Proposes Airships, Cloud Cities For Venus Exploration
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.

Comment: Re:Solar irradiance in the article? (Score 1) 200

by Ihlosi (#48623791) Attached to: NASA Study Proposes Airships, Cloud Cities For Venus Exploration
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.

Comment: Re:As with all space missions: (Score 1) 200

by Ihlosi (#48617357) Attached to: NASA Study Proposes Airships, Cloud Cities For Venus Exploration
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.

Comment: Solar irradiance in the article? (Score 1) 200

by Ihlosi (#48617323) Attached to: NASA Study Proposes Airships, Cloud Cities For Venus Exploration
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 ...

Comment: Let's do it. (Score 2) 200

by Ihlosi (#48617283) Attached to: NASA Study Proposes Airships, Cloud Cities For Venus Exploration
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".

Comment: Re:C is very relevant in 2014, (Score 1) 641

by Ihlosi (#48571811) Attached to: How Relevant is C in 2014?
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.

Comment: Re:Very relevent for small target embedded stuff. (Score 1) 641

by Ihlosi (#48563085) Attached to: How Relevant is C in 2014?
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).

Comment: Re:C is relevant because it is low level. (Score 1) 641

by Ihlosi (#48553989) Attached to: How Relevant is C in 2014?
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.

Comment: Small target! (Score 2, Interesting) 641

by Ihlosi (#48553951) Attached to: How Relevant is C in 2014?
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).

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