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Comment Re:EC will punish US Teachers (Score 1) 188

It will move the stock market. By a lot. In the long term, of course, because the ruling will have an impact to the accounting provisions which are not necessarily instantly are disclosed, or, for proprietary reasons, recognized in the financial statements.

So, you believe that Apple and other companies don't realize that they're attempting to evade taxation when they engage in these Dutch-Irish sandwiches?

And no, it won't move the market by a noticeable amount, any more than a tax increase or decrease moves the stock market by a noticeable amount, except maybe on the day it's announced.

Comment Re:If the singularity doesn't happen... (Score 1) 105

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!)

Comment Re:They want 600k (Score 2) 127

ACs don't see sigs. For someone to knowingly comment on sig content they must be able to see Slashdot from the perspective of a numbered user.

So, you're saying that there are people so pitiful that they would have a Slashdot account for browsing, but comment as Anonymous Coward because they don't want to be associated with their opinions?

Comment Re:Taxonomy and location (Score 1) 105

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) 105

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:What the hell is the big deal with "planet"? (Score 1) 105

The most ridiculous thing about the "cleared its orbit" standard is... MOST planets didn't clear their orbit. Jupiter, and to a lesser extent Saturn, did. Particularly in the case of Mars. Mars does not dominate it's neighborhood, a fact clearly reflected by how low of a percentage of asteroids are in a Mars resonance vs. Jupiter. Mars has a significantly lower Stern-Levison parameter than Neptune, and yet Neptune has freaking Pluto in its neighborhood. And even if one wants to argue that Pluto is too small versus Neptune to count as "not cleared", it certainly isn't too small compared to Mars to count. The reason Mars does not have things even bigger than Pluto in its neighborhood comes down to one word: Jupiter.

And I know some people will say, "but the Stern-Levison parameter says Mars would have". It says no such thing. The Stern-Levison parameter is about a body's ability to relatively clear its orbit of asteroids, not protoplanets. It's based around the size and orbital distribution of our current asteroid belt.

But of course, this was not a scientific reality seeking a definition. They had a definition they wanted (that Pluto wouldn't be a planet) and were trying to come up with some sort of scientific reasoning, any reasoning, as to why. This is quite clear from their statements on the topic, they already had the result they wanted and were playing around with different reasonings to get it. And this mangled, self-contradictory definition is what they came up with and passed at the last minute (when most people had left thinking that there either wasn't going to be a new definition or that it would be based around hydrostatic equilibrium, based on what had been discussed previously, and were fine with either outcome). And so now we have a situation where a "dwarf X" isn't an "X" from a body that otherwise declares dwarf things to be smaller versions of the same thing, where exoplanets aren't planets, based on a lie that all planets have "cleared their own neighborhoods", without any sort of clear definition as to what a "neighborhood" or "clear" is.

Heck, if I wanted to be pedantic I could point out that not even Jupiter would meet their definition because - again, to be pedantic - it does not orbit the sun. The point that Jupiter orbits (the Sun-Jupiter barycentre) is almost always outside the sun.

Comment Re:Improving taxonomy (Score 1) 105

While far be it from me to defend the IAU, that is just nonsense. If anything we need better definitions and more categories and the IAU got the ball rolling on this.

What the IAU "got the ball rolling on" was chaos. They had a bunch of astronomers telling planetary scientists to use a definition that they disagree with. Many have taken to just ignoring it, in the peer reviewed research. To give two examples of how absurd the definition is: 1) the definition states that something is only a planet if it revolves around the sun, not other stars - and yet the IAU has an exoplanets working group. Exoplanets aren't planets! 2) The concept that "a dwarf X isn't an X" is not only linguistically absurd, it's a view not even shared by the IAU itself, which is more than happy to consider, for example, dwarf stars to be stars.

The main reason stated by most astronomers who backed the decision is almost invariably (seriously, read interviews with them), "I don't want my daugther having to memorize the names of sixty different planets". As if that's even slightly a valid reason for making a scientific decision.

Jupiter and Earth bear almost no resemblance to each other and yet they both are planets.

Exactly! And yet rather than kick the gas giants out, they kicked out another solid body that has far more in common with Earth (including, I should add, active geology and weather) rather than the bodies that have almost nothing to do with Earth.

In reality they should probably be different categories of entities. We used to consider Ceres a planet a long time ago

And we should. Believe it or not, because some scientists in the 1800s changed their mind about something doesn't mean that this is some sort of eternally correct decision. They had no clue about the concept of what bodies would end up in hydrostatic equilibrium and the consequences thereof.

Let's go to biology. We label species all the time based on location and proximity to other similar animals rather than the much simpler "can they mate" question.

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?

Or geography. We label mountains and bodies of water precisely based on what they are next to. You could reasonably consider the Mediterranean Sea as a part of the Atlantic Ocean if you really wanted to.

So because it hasn't "cleared its neighborhood" does it suddenly become the Mediterranean Pond despite being a size that we traditionally call a sea? Do we arbitrarily declare that there's only 8 mountains in the world and all others are "dwarf mountains" that aren't really mountains because we think there's too many mountain names for kids to memorize?

Umm, ok. Presuming that is true...

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?

It would be equally true to say that Earth wouldn't be a planet if it wasn't orbiting the Sun but equally irrelevant as well because it manifestly does.

Right. Because it totally makes sense to have an perfect copy of Earth orbiting in a larger star's habitable zone (and thus have a lower Stern-Levison parameter) not be a planet while its perfect copy is.

Pluto is very much like Ceres and other big rocks

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. And should I add, one of my greatest peeves about the IAU's decision. Since their discoveries long, long ago both Pluto and Ceres had been nothing more than specks, dots of light. We knew next to nothing about either of them. Then finally, at long last, right before we were about to get real data on both of them, rather than even waiting for the data to arrive, they decided to make declarations about them. The most unreasonable time they could have picked in a century to do so, that's when they did it. And don't even get me started on how the vote went down...

Pluto is about as different from a "big rock" as you can get. Pluto has an atmosphere. With apparently complex nitrogen photochemistry and clouds going on in it. With snowfall and frosts, and a chemically diverse surface. And glaciers, carving out canyons. And signs of what appear to be flowing liquids of an unknown nature in the past. And cryovolcanoes. And tectonics. And types of terrain we don't even have a clue what they are. And the incredible Sputnik Planum, something never before seen in our solar system: effectively a planetary mantle exposed to the atmosphere, an area devoid of crust where the underlying eutectic-ices slowly roil on the surface in supermassive convection cells, with icebergs the size of mountains riding around on top of them and collecting on the shores.

This is what you call a "big rock"? It's a heck of a lot more geologically interesting than half the "planets". And absolutely nothing like the sort of primitive, unaltered, inactive bodies that it's now lumped in with.

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