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Comment Re:a very large planet, 15 times the Earth (Score 1) 135

And something basically to that effect was for a period at the IAU conference the definition being haggled over. A lot of people went home at that point thinking that either that would get voted in as the definition, or there would be no definition, and were fine with either outcome. The committee however changed the proposal before the vote came up.

Comment Re:Could you gush a little more? (Score 4, Interesting) 175

I've been debugging and rewriting a lot of legacy C# code recently, and I have to say that it's a breath of fresh air. I used to advocate Java, before Oracle went crazy, but after using C# I never want to touch that bureaucratic pile of over engineered crap and its litigious nutcase "owner" again.

Google: please, please, consider switching. You could even piss Oracle off by porting over the official JVM to Android, writing a Dalvik to Java byte code convertor, and letting legacy Java Android apps run at 10% of the speed they're supposed to, just to simultaneously encourage developers to move to C# and to end the lawsuit with Oracle completely unable to do anything about it.

Comment Re:The universe. (Score 1) 135

These are what the IAU came up with, in a vote that was very controversial among its membership. An association dominated by astronomers, not planetary scientists, who were by and large against the decision. And a set of terminology that you can often find flatly ignored in scientific papers. Example. In short, the only group that the IAU is able to bludgeon into using their term is the general public (using the "We're scientists, if you don't use our term you're wrong and ignorant" gambit), not the scientific community itself.

Comment Re:"Adult conversation next year?" (Score 5, Insightful) 246

In other news, the director of the Burgler's Association says that prolific door locks are hurting their business efforts. He was joined by the director of the Peeping Tom's Union announcing that prolific window coverings are hurting their ability to stay competitive.

Wow, that's weird that a technology designed specifically to protect against eavesdropping and unauthorized access makes a spy's job more difficult. You know what I want? I want a bunch of laws to get passed specifically to allow me to do my job with less effort and fewer skills, because my feelings get hurt when I have to actually work and use what I know. When I have an issue on a server that I'm having a hard time figuring out, I want someone to just call my phone with the solution. That would be fantastic, let's get right on that. In the meantime, I guess I'll just have to continue to do my damn job and get paid for the work that I actually do.

Comment Re: Weirdly specific statement (Score 1) 55

What is the limiting factor? Buildup of CO2?

People need a certain amount of oxygen for their metabolism, you need to carry that much. CO2 effects the blood pH: too little and the body is too alkaline, too much and it's too acidic. So, you need to maintain a precise amount of CO2 and remove the rest. The scrubbers in the space shuttle were able to regenerate the CO2-absorbent material after use, so there was use of power but material wasn't consumed.

Beyond this, you need to control temperature and humidity. The other requirements than atmosphere for crew survival are that you water, feed and shelter the crew, maintain orientation, and maintain a G-force envelope that doesn't injure the crew.

Comment Re:If the singularity doesn't happen... (Score 2) 135

Stop feeding the troll ;) If a person can't handle an argument without name calling, they're not worth your time.

For what anyone not trolling :) There is nothing magical about existing on Earth that allows a nuclear reactor to run. Earth does provide a few conveniences, mind you - your mass budgets are unlimited, and cooling is easier. But nothing about either bulk nor mass prevents nuclear reactors from operating in space, by any stretch, and the two main things limiting their use have been a lack of need and NIMBY (the former being little applicable in the former USSR, they used them quite a bit, although they still lacked a need for high powers and so generally kept them fairly small; in the US, NIMBY limited the US to just one launch, although the US developed a number of other systems, some to flight-ready status, on the ground).

The typical mass balance for a in-solar system fission fragment rocket (measured simply by MWt, not MWe, since thrust is direct) is about 20% payload, 20% structural, 35% reactor, and most of the rest toward various aspects of cooling. The nuclear fuel makes up only about 2% of the total mass (figures from the Callisto baseline). For an interstellar mission, however, the fuel would make up the a large minority or the majority of the mass, trading significantly reduced acceleration for significantly longer acceleration times. On an in-solar-system version, power density is about 6kWt per kilogram of reactor mass (that 35% figure above). This is actually quite low by large-space-reactor standards; many modern multi-megawatt reactor research projects for NEP and defense purposes (example) often deal with density figures of 50-100 kWe per kilogram, including cooling. But a fission fragment reactor has a sparse core and has to rely extensively on moderation / reflection to keep up a sufficient neutron flux; higher core density is prohibited because then the fragments would thermalize.

One thing that's neat about a fission fragment reactor is that, like systems like VASIMR, it can operate in various output modes, trading ISP for thrust as needed. In pure fission fragment mode it's ISP is is ridiculously high, nearly 1m sec; your thrust is purely the relativistic fission fragments from each reaction, carrying the majority of the reaction's energy away. However, you can inject gas into the stream as reaction mass, limited only by the density to which your magnetic nozzle can keep the stream confined. So where higher thrust maneuvers are needed, you can use the same engine (up to the aforementioned extent, of course; you're not going to take off from a planet with a FFRE!)

Submission + - September 19th SpaceX Launch will be visible across California, Nevada. (reddit.com)

Bruce Perens writes: The nighttime launch of a SpaceX Falcon 9 containing Iridium satellites at 9:49 PM PST Monday September 19th from Vandenberg AFB SLC-4 is likely to be visible across California and in some Nevada locations. Although Vandenberg has a landing pad for the Falcon under construction, this will probably be a drone-ship landing and some California observers might see two of the landing burns.

Comment Re:Taxonomy and location (Score 1) 135

So it's up to the planetary scientists to do something about it if they think it makes little sense

Do what? They make up less than 20% of the membership of the IAU. It's a bunch of astronomers. What do you want them to do, file a lawsuit?

They're doing the main thing that they can, which is complain about the "definition" foisted upon them, as Stern was doing above. Something you apparently find fault with.

All I hear is a bunch of bitching about it but no serious counter proposals.

That's your fault if you don't pay attention to the debate, because there have been tons of alternate proposals.

If the IAU decision wasn't scientifically useful then it will be ignored anyway.

And hence a giant stink that lowered the discourse for nothing.

How do you see this as even remotely similar? If you take a shrew from Ohio and you place it in Nepal, does it cease being a shrew and become a dwarf shrew that no longer counts as a shrew?

Actually biologists do stuff like that all the time.

No, they don't.

There are species that are considered different based almost entirely based on location

No, there aren't.

but it does happen and it's not irrational.

No, it doesn't, and yes, it is.

Seriously, you're going to cast doubt on the guy who came up with the Stern-Levison parameter that's used to make that distinction?

When he says something igorant, yes I am.

Right. Got it. The guy who co-invented the Stern-Levison parameter doesn't know how to calculate a Stern-Levison parameter. But you do. Thank you! I take it your name is Harold Levison?

Pluto is absolutely not "much like" "big rocks", and the fact that you'd make this claim is a profound expression of ignorance on the topic.

You are seriously arguing that Pluto is nothing like other "dwarf planets" or other large rocky/icy objects in our solar system?

Pluto is more like Mars than it is Ceres, at the very least. As for other dwarf planets... we have no idea, we've never even been there. Going by things that would be counted as dwarf planets if they were free orbiting, there's a massive range of properties. What's the universal property (apart from size / hydrostatic equilibrium / general terrestrial nature) between Pluto, Luna, Ceres, Ganymede, Callisto, Europa, Io, Titan and Triton? Answer: not a damn thing. They're all radically different environments. Some are more similar to each other than others, but they're anything but a logical "group" distinct from the terrestrial planets.

Versus "big rocks", however, the comparison is even more ridiculous. There is literally nothing beyond "they're both made of solid matter" in common between Pluto and a typical large asteroid. Including, for starters, Pluto isn't made of rock. It has some unknown percentage of rock in its interior, but it's overall made of ices, with a thin gas atmosphere (not all that different, structurally, from the ice giants Neptune and Uranus, although the latter two are obviously on a much larger scale and reach much higher pressures in the gaseous state before transitioning to the ice states).

Comment Re:If the singularity doesn't happen... (Score 1) 135

I'm sorry, I must be a nutter. I was under the mistaken view that we live in a world where there are many dozens of different designs for fission reactors that have been developed, with new designs being developed and prototyped every year, and full scale reactors being produced on scales orders of magnitude larger than is required for spacecraft propulsion. Little did I know! Thank you for correcting me for my sinful error.

Comment Re:It's not aliens (Score 1) 259

What's to say they will not have actually learned anything or grown beyond their imperialist phase by the time they are so advanced?

That's not really the argument, is it? By the time they're that advanced, we have nothing they need. If we have anything they want, it's either food or culture. Maybe sentients are a delicacy, so that's a potential threat, but otherwise we'd be more valuable as we are — producing art, literature and so on. Then they can point at the monkeys and laugh.

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