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Comment Re:Wow, and I thought the existing Sednoids were n (Score 1) 39

Another thing I think argues for a universe full of planets: star frequency is proportional to size. The largest are rarest while the smallest are the most common. This continues all the way down: M class stars (red and brown dwarfs) make up 75% of the stars in the universe. We have more trouble estimating brown dwarf counts than red because they're not easy to observe, but they appear very abundant. But once you get below the cutoff for D-D fusion... we just can't see them. Why should we assume that the distribution just stops at brown dwarfs?

Comment Improving taxonomy (Score 1) 39

"I think the IAU really embarrassed themselves with this," said Alan Stern of the Southwest Research Institute in Boulder, Colo. Stern leads NASA's New Horizons mission, which is sending a spacecraft to study Pluto up close. "They created a problem for themselves and for astronomy. It [the definition] created an unworkable algorithm for deciding what's a planet and what's not."

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. Jupiter and Earth bear almost no resemblance to each other and yet they both are planets. In reality they should probably be different categories of entities. We used to consider Ceres a planet a long time ago and then we didn't once we learned more. Definitions change as we get more/better information. If he has a better taxonomy then how about proposing it rather than bitching about the IAU?

"A river is a river, independent of whether there are other rivers nearby. In science, we call things what they are based on their attributes, not what they're next to."

Evidently the guy isn't terribly well informed. 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. 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. They are contiguous after all. We don't because we consider phenomena like currents to be important as part of the definition. Proximity and location very much can matter in taxonomy.

Further, Stern said, the criterion sets different standards for planethood at different distances from the sun. That's because the farther away a planet is from the sun, the bigger it needs to be to clear its zone. If Earth circled the sun in Pluto's orbit, for example, it wouldn't qualify for planethood in the IAU's eyes.

Umm, ok. Presuming that is true, so what? It's a definition. 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. If it doesn't work for some reason come up with a better taxonomy. Honestly compared to Jupiter the Earth is basically a dust mote so I'm not really sure what he's getting at. Pluto is very much like Ceres and other big rocks so it makes sense to put them in the same sort of category. Earth is rather different so it makes sense to categorize it differently. Same with Jupiter. We categorize stars in all sorts of different types so I don't know why people get so bent out of shape over doing it for orbiting bodies of rock and gas.

Comment What the hell is the big deal with "planet"? (Score 1) 39

Pluto is no planet!
Because it's not cleared its orbit.
Well, we have found almost a dozen others out there like Pluto!
We'd have to call all of them planets!

What the fuck is the big deal? I am still waiting for a really good reason that explains why "clearing its orbit" is so friggin' important. Technically, given its Trojans, Jupiter hasn't even done that. So let's call that biggest gasball outside the sun itself a planetoid.

I can see the "has to be large enough to have enough gravity to get round". Ok. Just for the sake of having a lower limit in mass. I can of course see the "has to orbit the sun itself and not another object" so we can tell it apart from a moon (which gets our very own planet into rather hot water, considering that outside Pluto we have the biggest moon compared to planet mass, at what point do you have a dual-planet system rather than a planet-moon system? Probably when the common center of mass is outside both bodies, I'd say).

But "clearing out the orbit"? C'mon, find a better reason if you want to keep the planet club exclusive and not include the likes of Pluto. I bet it's just 'cause you noticed that it's half-black, isn't it?

Comment Never is a long time away (Score 1) 39

We will never achieve speeds of hundredths of C.

Earth is moving through space along with the rest of our local group at approximately 375 miles per second. I believe that works out to approximately 0.002C so that means we are almost moving at hundredths of C already without leaving the planet's surface.

Second never is a very long time. We used to think that we would never exceed the speed of sound either. Hell, 150 years ago we weren't sure powered flight was possible. I see no reason why it is impossible in principle for us to travel considerably faster than we already have managed.

The fastest we have achieved is 0.000542% c.

With a chemical rocket. It doesn't follow that that we cannot develop technology to go faster than that. I would agree that we won't go significantly faster than already achieved speeds in the near future but in 100 or 1000 years? I would be surprised if we didn't exceed that by a lot presuming we haven't killed ourselves off by then. In actuality we probably already have propulsion system technology that could send us much faster than we have already gone. What we lack are habitats that can keep us fragile humans alive during long duration high velocity journeys far from Earth.

Comment Re:There is a 9th planet (Score 1) 39

You mean 10th. You forgot about Ceres.

Under no reasonable standard is Pluto 9th. 10th, fine. I'd go out on a limb and argue at least 17th, also adding in the "planetary moons" that meet a hydrostatic definition even better than Pluto: Luna, Ganymede, Callisto, Europa, Io, Titan, and Triton. Using "planet" on the basis of of "body large enough to assume hydrostatic equilibrium but not undergo fusion" and moon as "body that orbits a planet".

Hydrostatic equilibrium is a very meaningful definition. A body not in hydrostatic equilibrium is made of primitive materials; it's the sort of place you'd go to learn about the formation of our solar system. A body in hydrostatic equilibrium has experienced internal heating, movement of fluids, chemical reactions, etc. It's the sort of place you go to learn about geology and search for life.

Or if you'd rather, you can apply the Captain Kirk test. Put it up alone by itself on a viewscreen. Would Captain Kirk say "Beam me down to that planet" or "Beam me down to that asteroid?" It's silly, but it's basically another way to say, "is the word functioning as normal people would use the word?" Of course, if there was another, bigger body in the background, they might say "beam me down to that moon". But we've all seen sci-fi where we're told that a body is a moon but people keep accidentally referring to it as a planet. The Forest Moon of Endor, for example. If it's a gigantic round thing, a part of us wants to call it a planet, even if we also know it's a moon. No reason not to just have them both as descriptive terms: a "planetary moon".

(And IMHO, if there's anything we should be kicking out of the "planet" club, it should be the gas giants... followed next by the ice giants. Seriously, how much is Jupiter like Mars?)

As for Stern, he once presented a rather interesting classification scheme (ironically, in the same paper as the Stern-Levison parameter was proposed). Basically, forget about all of these nouns, just have a good list of adjectives. You can have various things from sub-dwarf planet to super-giant planet to indicate the mass; prefixes like "gas" or "ice" or "rocky" to indicate the character: other adjectives to indicate its orbital parameters (including its "neighborhood" if you prefer), etc. Why limit yourself? Cite as many adjectives to describe it as are appropriate to the situation.

Comment Re:If the singularity doesn't happen... (Score 2) 39

First off, there is no "theoretical maximum speed" to how fast a given propulsion mechanism can get you. You can get to 0,999c by shooting tennis balls out the back of a spacecraft with a slingshot - if you're willing to build a spacecraft comparable in size to the universe ;)

Secondly, nuclear pulse drives really are an antiquated idea, I don't know why people obsess over it. Their minimum sizes are way too large and they're inefficient, with low ISP compared to more modern ideas. Longshot, BTW, is technically NPP, although a more modern variety. Still inefficient and very heavy, and nowhere close to a technology that could be achieved in a reasonable timeframe from where we are today.

Of the many, many concepts now available, I'd personally go for fission fragment propulsion. It's so straightforward: get the most out of fission by having individual fission reactions propel your spacecraft directly. And from a design perspective, it's pretty straightforward particle physics / fission reactor design, just in an unusual (suspended) configuration - the suspension already demoed in the lab. But that's, again, just one of many possibilities.

Comment Re:problems, lol (Score 1) 131

Sadly, I'm pretty sure I have shipped code with Python syntax errors in error handling paths. My C or Go might have been buggy, but at least it friggin' compiled!

Your Python program compiled too. If you didn't test every path through the program written in C or python you probably did miss some bugs. Don't blame the language.

Studies consistently show that the number of bugs per thousand lines of code is roughly the same across different languages. For the same functionality, a verbose language like Java will have more bugs than a concise language like Python. Go ahead and write websites in C if you want.

Comment Re:If the singularity doesn't happen... (Score 1) 39

Unfortunately, no. Their gravity is far too weak for them to provide a significant "slingshot" effect.

Also, the fact that there are many of them isn't really the big help that it might sound. One, there's many in a very large volume of space. Two, they have very different orbits. Even if two are physically "close" to each other in a given location at a given point in time, you still have a lot of delta-V to overcome.

Comment Re:Wow, and I thought the existing Sednoids were n (Score 3, Interesting) 39

I don't think the process of exchange can be fast - if those bodies had galactic escape velocity, after all, they wouldn't stay here for long

They don't have escape velocity; they're stuck with us until something perturbs them. But the key point is that when something is that far out, it's very easy to perturb. And our stellar neighborhood is not static. Indeed, one of the alternative theories to explain the sednoids is that rather than a planet X, the orbits are due to one or more stellar passes nearby our solar system.

So far we're still not seeing very far out, we're just barely spotting these things, and only when they're near perihelion. There's much more out there yet to discover, and so far all signs point to that our solar system doesn't just "stop" anywhere, it just keeps on going. Heck, we only know about the Oort cloud because comets have such distant aphelions.

Comment Close the doors? (Score 1) 148

And if their profitability falls below what investors demand as a return, then those companies move to China or close entirely, and investors put their money elsewhere. And if you don't leave investors any place to put their money with sufficient profits, they simply stop investing altogether.

In general your argument is nonsense. What do you mean "move to China or close entirely"? Do you seriously think Apple is going to close down if they make 20% net margin instead of 25% net margin? Do you seriously think they are going to become a Chinese company? Spare me. Apple already is in China in about the biggest way possible. They aren't going to move and they certainly aren't going to ignore the EU market. At most a company might relocate some production but production isn't sales and taxes occur where the sales do (or should anyway). Companies aren't going to close their doors because they make a 6% profit instead of a 10% profit. It just doesn't work that way. They might change beneficial owners but the company won't disappear. Your argument makes zero sense.

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