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Comment: Re: Scaled Composites renamed (Score 1) 37

by jd (#48909771) Attached to: Virgin Galactic Dumps Scaled Composites For Spaceship Two

Solar sail can achieve 25% light speed, according to NASA, and Alpha Centauri is 4 light years away.

You want a manned mission (with robots doing all the actual work) to determine if the conventional wisdom that a manned mission to the outer planets is physically impossible is correct. Even if the pilot dies, you learn the furthest a manned mission can reach. There's seven billion people, you can afford to expend one or two. Ideally, they'd be volunteers and there'll be no shortage of them, but if you're concerned about valuable life, send members of the Tea Party.

Comment: Re: Scaled Composites renamed (Score 1) 37

by jd (#48909107) Attached to: Virgin Galactic Dumps Scaled Composites For Spaceship Two

No big surprise. The military are willing to invest what it takes for what they need. Military entities are, by necessity, pitifully naive when it comes to anything useful, but once they specify what they think they want, they don't shirk at the cost, they get the job done. A pointless job, perhaps, but nonetheless a completed job.

The corporate sector wants money. Things don't ever have to get done, the interest on monies paid is good enough and there hasn't been meaningful competition in living memory. Because one size never fits all, it's not clear competition is even what you want. Economic theory says it isn't.

The only other sector, as I have said many times before, that is remotely in the space race is the hobbyist/open source community. In other words, the background behind virtually all the X-Prize contestants, the background behind the modern waverider era, the background that the next generation of space enthusiasts will come from (Kerbel Space Program and Elite: Dangerous will have a similar effect on the next generation of scientists and engineers as Star Trek the old series and Doctor Who did in the 1960s, except this time it's hands-on).

I never thought the private sector would do bugger all, it's not in their blood. They're incapable of innovation on this kind of scale. It's not clear they're capable of innovation at all, all the major progress is bought or stolen from researchers and inventors.

No, with civilian government essentially walking away, there's only two players in the field and whilst the hobbyists might be able to crowdsource a launch technology, it'll be a long time before they get to space themselves. The military won't get there at all, nobody to fight, so the hobbyists will still be first with manned space missions, but it's going to take 40-50 years at best.

We have the technology today to get a manned mission to Alpha Centauri and back. It would take 15-20 years for the journey and the probability of survival is poor, but we could do it. By my calculations, it would take 12 years to build the components and assemble them in space. Only a little longer than it took for America to get the means to go to the moon and back. We could actually have hand-held camera photos taken in another solar system and chunks of rocky debris from the asteroid belt there back on Earth before Mars One launches its first rocket AND before crowdfunded space missions break the atmosphere.

All it takes is putting personal egos and right wing politics on the shelf, locking the cupboard and then lowering it into an abandoned mineshaft, which should then be sealed with concrete.

Comment: Re:They better be damn sure we're not home... (Score 1) 365

Heads are also heavily protected. Have you never seen the gear SWAT teams, riot police, soldiers, etc. wear? You really think they walk around with their head exposed?

Since those guys are likely to be in full heavy body armor as well and humans need to see and breathe the face is still the weak spot, unless you got a high powered rifle or something. Not that you're going to win against a whole SWAT team anyway, but one lone nutcase who has you backed into a corner... I'd aim for the face.

Comment: Re: DirectX is obsolete (Score 1) 125

by TheRaven64 (#48902995) Attached to: DirectX 12 Lies Dormant Within Microsoft's Recent Windows 10 Update
Actually, a lot of these games just use WINE's implementation of DirectX. This either translates the calls to OpenGL or implements a DirectX state tracker directly if you have Gallium drivers configured correctly. The same is true of a lot of Mac games. Good luck getting WINE to run on a console though...

Comment: Re:DirectX is obsolete (Score 1) 125

by TheRaven64 (#48902991) Attached to: DirectX 12 Lies Dormant Within Microsoft's Recent Windows 10 Update

Your typical GPU driver is about 10MB of object code. It contains a complex optimising compiler and controls a device that has complete DMA access to your computer. It is written with speed as the only significant goal. Making a GPU driver 1% faster contributes enough to sales to pay the salaries of several driver developers. Making the GPU driver more secure generates zero additional sales.

The shader code that's fed into this stack from WebGL is sanitised and is completely safe to run, assuming that your driver stack is 100% bug free. Still feel safe?

Comment: Re:DirectX is obsolete (Score 1) 125

by TheRaven64 (#48902983) Attached to: DirectX 12 Lies Dormant Within Microsoft's Recent Windows 10 Update

If you write a game that uses Direct3D, you can easily target Windows, XBox, and Windows Phone. If you write a game that uses OpenGL, then you can easily target all of the major desktop, mobile, and console platforms. If your game runs on a generation-old console, then it will run on current-generation mobiles as well. This gives you three markets: First release for high-end PCs, second for consoles, third for mobiles. You can get a solid revenue stream out of each one. You don't lose the Windows marked by choosing OpenGL, but you do lose every other market by using Direct3D.

That said, the APIs are so similar these days that you'll typically use some middleware to provide the abstraction. All of the important code is written in the shaders and these are much easier to port between GLSL and HLSL than they are to port between different GPUs and maintain performance.

Comment: Re:Modula-3 FTW! (Score 2) 458

by TheRaven64 (#48902963) Attached to: Ask Slashdot: Is Pascal Underrated?

Implementing this in the standard library means that the language needs to support pass-by-reference (which Pascal and C++ do, but C doesn't). This single feature does a lot to reduce readability. In C, I know that inc(x) is a function that does not modify the value of x, without reading any additional code[1]. In Pascal or C++, I need to look at the definition of inc() to know if x will be the same before and after the call.

An important idea at the core of readability for a language is the amount of code that I have to read to understand a single line. In any language that has pass-by-reference, this amount is larger than a language that doesn't. To achieve the same thing in C, I'd have to write inc(&x), and then everyone reading that code would know that x may be modified. (Note: the almost-equivalence of array and pointer types in C is a good counterexample where Pascal wins massively in readability).

[1] It could be a macro, but most coding conventions require macros that can't be used as if they were functions to be all-caps.

Comment: Re:Modula-3 FTW! (Score 1) 458

by TheRaven64 (#48902951) Attached to: Ask Slashdot: Is Pascal Underrated?
This would be true, except for two things:
  • Lines with more than 66 non-whitespace characters decrease readability.
  • Statements with more than 66 non-whitespace characters are common in most programming languages.

This means that you end up either with lots of continued statements or lots of overly-long lines in Python. If you have the former, then it's hard to see the indentation. If you have the latter, then you can see the indentation but the overall readability suffers. This can be fixed by using tabs for semantic indentation and spaces for alignment and an editor that supports highlighting tabs, but the Python style guides tell you not to do this.

Comment: Re:Modula-3 FTW! (Score 1) 458

by TheRaven64 (#48902941) Attached to: Ask Slashdot: Is Pascal Underrated?

There are some simple things where C is far more readable to a moderately experienced programmer. Consider the beginning and ending of blocks. In pascal, these are signified by begin and end. When you look at a chunk of Pascal code, they can be hard to pick out because they're just words in a sea of words. In C, you use the { and } symbols. These are symmetrical and the human brain has spent a lot of time evolving to be trivially able to spot symmetry because symmetry normally means 'predator about to try to eat me'. You can very quickly spot a column that has a { at the top and a } somewhere later (much more easily if they're aligned together and there's nothing else on the line). There were some studies done in the '80s that confirmed this, though sadly a lot of C coding conventions specify brace placement in a way that reduces readability.

The main strength of Pascal is that it forces you to think more than C. If you don't write what you mean in Pascal, it usually fails to compile. C will happily do... something. This level of redundant verbosity makes Pascal both quite a frustrating language for experienced developers and a great language for teaching. I find that people who learned Pascal tend to write better C code than those that didn't, but neither group has a strong desire to write Pascal.

Comment: Re:Not a problem (Score 0) 76

by Kjella (#48901289) Attached to: SpaceX, US Air Force Settle Spy Sat Dispute

SpaceX will sell the Air Farce the rockets. The AF launches their gear into orbit. SpaceX has nothing to do with it more than to get paid for the hardware and some support personnel who will have to have security clearances.

These aren't just slightly confidential, state of the art spy satellites is top secret business. They'll be worrying that a SpaceX employee can plant something to steal technology, reveal capabilities, damage or compromise the satellite once the payload is installed. I'm guessing you need just a microscopic amount of C4 if it can hook into the antenna and wait for a self-destruct signal so that when you need them the most they go boom and the screens go dark.

The difference between reality and unreality is that reality has so little to recommend it. -- Allan Sherman

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