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2 Planets Can Share the Same Orbit, In 3 Different Ways
StartsWithABang writes: One of the most important characteristics of a planet, at least according to the IAU definition, is that it clear its orbit of all other bodies. But if we allowed for a special caveat — the possibility of two similarly-sized objects sharing the same orbit — could we have a stable configuration where that occurred? Surprisingly, not only is the answer yes, but there are three ways to do it: to have one at the L4/L5 Lagrange point of the other, to have a close-orbiting binary planet, or to have orbit-swapping worlds, where they periodically change spots with one another. Unbelievably, our Solar System has a history of all three!
One Orbit
One of the three criteria to be a planet is that it clear its orbit of planetesimals. However, the article points out that Earth shares its orbit with an asteroid known as 3753 Cruithne and the outer planets share their orbits with many such objects. Strictly speaking, this would mean that they fail to satisfy that criterion for being a planet. The same issue would arise with a binary planet, which also seems absurd.
Given that the third mass needs to be negligible for the Lagrange points to work (at least according to Wikipedia), to me it seems like this situation might be more like a strange type moon rather than a planet. What is or isn't a "planet" is just a random definition so there isn't really a right answer.
GENERATION 27: The first time you see this, copy it into your sig on any forum and add 1 to the generation.
How many different ways are there to rehash shit that everybody knew since forever into crappy clickbait articles?
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
Stack overflow.
Slashdot, fix the reply notifications... You won't get away with it...
This is an article for "Memento" like people.
Slashdot, fix the reply notifications... You won't get away with it...
This. Seriously, I'm getting sick of having Ethan's blog everywhere I go. Guy's good at manipulating social media, but there's nothing on any of his post that isn't just a rehash of things that Slashdot and other tech/science blogs have already linked to years ago.
One of the most important characteristics of a planet...
There's three characteristics, and this is probably the least important. But if you consider all three to be "the most" important, then I suppose it's one of them. That seems like a pretty silly way to express yourself, though. Personally, I'd probably just say "one characteristic".
Also note that we're talking about the IAU definition, which is not necessarily the only definition. Dictionaries still haven't accepted the IAU definition, and may never do so, because the IAU defines a planet as orbiting the sun, while science fiction writers continue merrily talking about planets around other stars, and show no signs of changing.
... please at least check whether the links in the submission are going anywhere...
Speak for yourself. I read the whole article, and enjoyed it. Not everyone knows all the intricate details of planetary orbits.
Can we please have warnings on links to Forbes? Those interruptions for their (usually stupid) "thought of the day" are really annoying. Perhaps editors should look for alternative sources where possible.
const int one = 65536; (Silvermoon, Texture.cs)
SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
I agree.
The guy might be an alright physicist but he's almost painfully naive about the Real World he happens to inhabit.
He needs to stick to pop science blog posts and leave the politics and history to the grown ups.
He (unbelievably) still thinks that the American revolutionary War was somehow of earth shattering consequence and wasn't a mere sideshow to the main event playing out on the Continent, as one example.
He also doesn't understand that the French vs British War in the North Americas was won by the French with a minor supporting role played by the native colonists who weren't too keen on paying the enormous debt they incurred to the British keeping them safe during the previous Indian Wars, or having anyone interfere with their lucrative smuggling operations. He even thinks having Americans cheerfully slaughtering each other in the tens of thousands a year with their "gerns" is something that other countries aspire to !
I know, I know.....it's laughable. Stick to nice pictures of stars Ethan.
Genuine, or shilling ... hmm, hard to tell.
http://suki.ipb.ac.rs/3body/
Boo hoo sexconker, you are a moron and don't want this to be pointed out because, like with Pluto, it's all about your outrageous ego stroking.
There can't be another moron on the internet so prone to using ALLCAPS and *asterisks* to make his mistaken point, so hellbent on defendint the IAU definition against all reasons, so obsessed with the accusation of american jingoism. You are clearly Wow, the obtuse commenter from Ethan's scienceblogs page.
You should seek therapy.
"Nobody ever asks about everyday phenomena" - Feynman complaining about people like you.
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
There can't be another moron on the internet who brings up inconsequentialities and pretends that somehow they are proof of error in the arguments!
YOU ARE REI!
Emphasis (typography) - Wikipedia, the free encyclopedia
... Of these methods, italics, small capitals and capitalisation are oldest, with bold type .... In Internet usage, asterisks are sometimes used for emphasis (as in "That was *really* bad").
https://en.wikipedia.org/wiki/Emphasis_(typography)
If the text body is typeset in a serif typeface, it is also possible to highlight
===
Of course, ignorance of reality is the hallmark of the "American Exceptionalist". As well as obsession over the inconsequential when you have nothing substantive to say, but must hear your voice anyway.
It's lonely out in space.
On such a timeless flight.
Just wanted to mention Earth's twin planet Mondas
https://en.wikipedia.org/wiki/Mondas
A) It's not a science mag.
B) It's javascripted/paywalled to fuck.
C) The original article fails on Betteridge's Law
D) Slashdot used to actually edit, now they're an HTTP version of an uncurated RSS feed,
Co-orbital configuration is already a thing - https://en.wikipedia.org/wiki/...
Slashdot supports <b> and <i> tags. I don't know what kind of primordial ooze you just crawled out of, but this is civilization, son, and you'd better act like you're part of it while you're here.
Go soak your head
Inconceivable!
Orbit clearance seems like a silly line to draw. Aren't most of the inner city planets' orbits cleared primarily because of the presence of Jupiter? So, the neighboring bodies are the primary factors that define a planet then? And where do orphaned "planets" fit in?
Why? Because without that, all the asteroids are planets. They orbit the sun, not another planet after all. So it would seem silly NOT to include the dominance of the orbit as a parameter.
It's only silly if you want to keep Pluto a planet, since that's the biggest problem it has. If it had been EXACTLY THE SAME but placed somewhere between Mars and Jupiter, it would be an asteroid and nobody would have batted an eyelid.
"Aren't most of the inner city planets' orbits cleared primarily because of the presence of Jupiter?"
No.
Look at the moon. See all those pockmarks? That's the result of the moon clearing up objects in the earth orbit. You can see some still on the planet earth, but weathering means almost all of them are gone from view.
The fact you get this wrong is why you're not really a valid arbiter on what should define a planet, since you don't know enough about what is up there and what it does to make an informed choice.
Since the moon orbit the sun, not the Earth, doesn't the definition of a planet not apply to the Earth ?
(the moon always curves toward the sun, never away, during it's 1 year journey. It does wobble on a montly basis
that allows the earh and it to swap arouind as being furthest from the sun.)
But then again if planet really means 'wandering star', then the ground (Earth) and the Moon (Luna) are not planets
either.
And I will quote again: "In Internet usage, asterisks are sometimes used for emphasis (as in "That was *really* bad").", NOTHING of which is countermanded or rendered invalid by the presence of tags. They don't stop asterisks being there or meaning what they mean.
Talking of "meaning" what the hell is supposed to be "proven" by their use? Note too, despite there being a quote tag for slashdot markup, the quote marks are STILL used without comment. It doesn't prove anything other than this was the best a moron could come up with to argue someone was inherently wrong.
Because punctuation was being used differently, this apparently renders otherwise logical arguments wrong.
And ends with me leaving Slashdot for a few months.
Enough of this SWAB crap!
Exactly on other side of Sun so you would never see it. But I dont think this is stable. Also since Earths orbit is ellipitical, the speed is not uniform through ot the year. So part of the years wouldnt be halfway apart and possibly visible.
My interpretation has been that the French helped with the Revolution to keep a large fraction of British forces occupied 'over there', so the French wouldn't have to fight them at home.
Also, it's a little-recognized point, but it's quite arguable that George Washington, as a fairly new officer in the British Army, accidentally started what we call the French and Indian war. He was tasked with building a fort at the confluence of the Allegheny and Monongehela rivers, which join to become the Ohio, in what is now Pittsburgh. A French force wandered by, on the way toward (IIRC) Virgina. Washington's force attacked and killed most of them (again, IIRC). As it turned out this was not, as Washington had thought, a raiding party but a diplomatic one. Oops.
But the Revolution was in fact more significant than what you propose, for at least two reasons. 1) This was the first country where Rousseau's and Locke's ideas about the sovereignty of the individual 'man' over the government were explicitly defined in the fundamental law of the nation - Britain had gone some way in that direction, but primarily only with respect to the relations between the King and the aristocracy. Even Hamilton was aghast at the prospect of the great unwashed masses actually being able to vote. 2) This was the first country that was defined not by ethnicity or geography but by the founding principle.
As various people said at the time, democracy has generally not been successful - at that time no democracy had ever survived more than about 200 years, as the two forces of people voting themselves largesse out of the public till, and the influential continually manipulating the system and the people to give themselves absolute power (sometimes using 'bread and circuses' - a term going back to Pericles, who caused the eventual destruction of Athens a few decades later) will eventually bankrupt the nation, which will then turn to military rule or defeat by a nearby enemy. From Greece and Rome to Argentina and Venezuela, we see this happen over and over again.
It's easier to be a result of the past, but more fun to be a cause of the future! http://www.spacefinancegroup.com/
Your crazy style, spammy formatting and weirdly unjustified rudeness and profanity makes you appear like someone who hasn't grasped a lot of the basics.
Either get some lessons, or get someone else to write your posts. Or stand condemned as an asshole.
Given that the issue at hand appears to be a matter of resolution and opinion, the GP (Rei) appears by far the most measured and rational person. You sound like someone who just thinks they're right and will shout down anyone else. IANAA and I'm pretty much on the fence on this issue but now I'm wondering whether the whole planet vote thing was rigged by, well, assholes...
Slagging off the actual experts by claiming they're clueless nobodies, claiming "Pluto is not a planet" is being weaponised, shitting over NdT because he agrees with the experts.
IT WAS ENTIRELY JUSTIFIED TO CALL IT GOBSHITE!
If your claim here is correct:
"1) This was the first country where Rousseau's and Locke's ideas about the sovereignty of the individual 'man' over the government were explicitly defined in the fundamental law of the nation - Britain had gone some way in that direction, but primarily only with respect to the relations between the King and the aristocracy. Even Hamilton was aghast at the prospect of the great unwashed masses actually being able to vote"
why the hell were the unwashed masses NOT allowed to vote, only landowner males of certain standing?
Those would have BEEN the aristocracy in 17th Century Britain.
The Ringworld is unstable!!!
Star Trek transporters are just 3d printers.