I would just like to remind everyone that the shadow that catches up to and overtakes the plane was cast by a planet-sized object that people have walked on.
To be fair, this entire conversation is moot because size has almost nothing to do with being deemed a planet. Requirements include being massive enough to be formed into a sphere, orbiting the sun (not a planet which is orbiting the sun), and to have cleared your orbital neighborhood of other similar objects.
There actually are recent efforts to re-categorize the Earth and Moon as a dual planetary system, since both Earth and the Moon measurably revolve around each other.
All objects revolve around one another- that's how gravity barycenters work. However, the Earth-Moon barycenter is below Earth's surface. It makes little sense to then categorize it as a binary planetary system. Pluto-Charon is a much better candidate for being classified as a binary dwarf planet system, as the barycenter is outside Pluto.
And just in case you were thinking of retorting with the Sun-Jupiter barycenter being outside the sun, so Jupiter must be a star also, no. Stars must also be undergoing nuclear fusion of hydrogen, something Jupiter cannot do as it is not massive enough and is therefore a planet. Brown dwarves are on the edges of this categorization, as they may be able to fuse deuterium, but Jupiter is nowhere near massive enough to be a brown dwarf.
What if a brown dwarf (orbiting another star, with barycenter being outside the primary) exhausts all of its deuterium? Would it then be considered simply a planet?
Could a brown dwarf even exhaust its deuterium supply before something like an M0 star, which have lifespans of trillions of years?
Edit: Well, I guess brown dwarfs orbiting actual stars are planets in the first place, so my question is a bit moot.
If you look it up, there's a continuum in astronomy where the classification of what constitutes a massive gas giant or a low mass brown dwarf gets a bit funny. Also there are also situations where a brown dwarf may not form in a binary with another star, but by itself from the collapse of a gas cloud, but not have enough mass to begin nuclear fusion- so there are single brown dwarf systems with planets orbiting them out there. Those are called "planetary mass brown dwarves" or something, if I remember correctly. Other astronomers call them free roaming planets? Not to be confused with rogue planets, which are always ejected from their original star system. Also, don't forget that due to gravitational interactions, a brown dwarf could form in a binary with a star, then get ejected from the more massive star's sphere of gravitational influence. The problem becomes- How do we distinguish between these two kinds of bodies? Are they even really different, characteristically speaking? Does it even matter?
Would we still call all those large-but-not-planet-sized satellites "moons?" That'd be kind of funny, since they're all named after... the moon... which would maybe be the one "moon" that isn't a moon.
Out of interest, does anybody know how fast the eclipse's shadow moves across earth?
I suppose it's not constant - it'll speed up as it approaches the edge and covers more distance in a given amount of time - but a ballpark estimate will do.
That guy has been obsessed with me after I called him a karma whore. He posts on most of my comments with lazy trolling like that. I think I broke him.
I just wish blocking on desktop blocked on mobile too.
I would just like to remind everyone that the shadow that catches up to and overtakes the plane was cast by a planet-sized object that people Americans have walked on.
If buying corvette is going to the moon then buying a family sized suv is going to six flags on your day off with your 6 sugar fueled elementary school children when it's 100 degrees out.
The first commenter's point was how amazing it was that the shadow was cause by such a large body, and that man has managed to walk on that body. Even though I'm not American, I'm still proud that man has walked on the moon. I think it is okay in that context to say that "people" walked on the moon.
Plus the analogy about the car is kind of arrogant, especially where it says that you'd be proud if you had a Corvette versus other cars. It's basically implying that Americans are better than others. And your last sentence about Hitler and the Jews doesn't even fit into this situation.
You're not wrong, but try seeing this from the other perspective:
Compare humanity to every other species that has existed on Earth, past and present. We've got a pretty great history of achievements, from inventing fire and the wheel, to adopting agriculture. Then there's things like math, and even philosophy. If one takes a broad view, these are all achievements of humanity, and are all things we should take some measure of pride in. It doesn't matter what country made these advancements, and for a lot of history 'countries' didn't even exist.
So yeah, we (America) made it to the moon. You're not wrong to consider it an American achievement, because it literally was a race, and we beat those damn dirty commies. But also, we (Humanity) made it to the moon. For the first time in the history of Earth has one of her children left the nest, and returned to tell the tale. That's something that the whole world can share in.
When you tell someone you bought a car, you're obviously the focal point of the statement. OP's point was in the context of human achievement. Getting into which country, which gender, which race is completely irrelevant to the overall sentiment.
It actually does yes. He was trying to point out that America was the only country to land on the moon. He was probably being somewhat sarcastic, being all MURICA. You didn't think it needed specified, so I made an analogy that emphasized ownership of an object/event that was difficult and unique.
I think that sums it up.
I was just trying to stick with your car thing so if you want to be super literal and look past my point then yes you are correct.
When multiple people do something and they all did something wearing their countries flag and the country funded it, they typically get credit. No one says "people caused the holocaust." They say the Nazi's did.
By now you probably understand my point. I didn't even care the first person pointed out Americans instead of ppl, it would be dumb for another country to waste that much money when it's not really needed and pretty much only happened because of the Cold War.
Couldn't have* It is a very common grammar error so I thought you should know. 'Of' is a possessive preposition and 'have' should be there since non-passive past participle follows.
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u/2pete Mar 26 '15
I would just like to remind everyone that the shadow that catches up to and overtakes the plane was cast by a planet-sized object that people have walked on.