From the BBC yesterday: Alien star system buzzed the Sun 70,000 years ago. Actually it was two stars and they passed between the Sun and the Oort Cloud. Edited correction: They passed through or near the outer edge of the Oort Cloud. There's been a theory in the past that something might disturb the Oort Cloud from time to time sending a slew of comets toward the Sun (with target Earth in the way). Nemesis Star (for those of you who don't know what it is) I can't wait to hear more about these passing stars and wonder how many other significant events in the solar system are also discovered if this changes what we are looking for out there in our neighborhood.
I saw this posted on a friend's wall on Facebook this morning. It will obviously mean much more to you, Ginger, but I still find this sort of thing amazing - if not slightly mind-boggling to try and imagine in my head.
Amazing is an understatement. This is the discovery of a lifetime for astronomers. Other relevant stuff (more to come as I read away on this matter): Voyager 1 is not yet to the Oort cloud.
Here's the abstract: The Closest Known Flyby of a Star to the Solar System It's interesting, this star pair isn't thought to have perturbed many comets. From the BBC news article: But from the abstract: "dynamically important Oort Cloud perturbers may be lurking among nearby stars." So we can expect more eyes on the skies looking for other perturber candidates. And in about 12 months we can expect to be flooded with a batch of new Nemesis sci-fi stories.
The Nemesis star was supposed to be something in orbit around the sun. As far as I know there is still no evidence of that (although last I heard certain mass/distance ranges have not been ruled out). The report here is about a stellar flyby. Such events have no doubt occurred many times during the history of the solar system although just how often is unclear. The 0.8 light year distance mentioned in the article is not particularly unusual. In 1.4 million years Gliese 710 may pass a similar distance from the sun. It, however, is a much more significant star (K spectral class). It will shine brightly in our sky at its closest approach and probably have a much stronger dynamic impact than a red dwarf would at that distance. There has been some academic work done trying to predict the effects of the Gliese 710 encounter but I believe it concluded there would be minimal impact (no pun intended!) even then. I notice the BBC article bills the event they are reporting as, "An alien star passed through our solar system..." This is typical media hype for sure. It's a bit questionable to call 0.8 light years "our solar system." The headline makes it sound like the star got closer than Neptune or some such.
Isn't the Oort Cloud considered the outer boundary of the solar system? 0.8 light years would put the star well within that, wouldn't it? (Give 100,000 AU for the Oort Cloud). If nothing else, this research seems to show proof that this has happened at least once, and thus demonstrates that hypotheses that posit such an event are plausible.
Its a cool find, but I don't really see how its that significant. It isn't the type of discovery that has applications or even the type of discovery that will result in important discoveries down the line. We knew it was possible for stars to pass closely to each other and now there is just an instance of it with our solar system. It sounds like they already had some idea of the probability before this. I don't think its much different than knowing how rolling a dice works beforehand but then saying its some significant discovery that three sixes were rolled in a row. It might be more important if the passage of this system had actually caused a comet shower and attributed to some crater on Earth, but the article says the passage didn't even do anything. Its just pointing at where something is and where it used to be and marveling at where it used to be. Also, this has nothing to do with the nemesis star, which by the way just by Occam's Razor would seem like a pile of poop. If extinction events even had a pattern, which is debatable, looking at patterns on Earth might be a better place to start than on the other side of the Oort cloud halfway to the next star. To be fair, the thread title is very enticing , and if it hadn't been as enticing I probably wouldn't have read the article. I'm glad I read the article. Someone should get a job writing tabloid headlines. In summary, the previous position of something was discovered and this position had no influence on anything of importance.
Spoilsport! You're ruining all the fun. Yes to some of your points, not so much to others. Yes, now that I have reviewed both the abstract and Nemesis, this is not the solar orbiter hypothesized in 1984 that has a periodicity consistent with recurring mass extinctions. But it is still fascinating that a star was tracked back to such a recent fly by. As for the boundary of the solar system, I don't care that readers will misunderstand the headline, I didn't misunderstand it. The Oort cloud is technically part of the solar system. Fascinating fact: That will give people some idea of the distance to the Oort cloud. Long period comets believed to come from the Oort cloud have >200 year periodicity, while shorter period comets are believed to come from the Kuiper Belt. I see in reviewing this topic there are currently about 3,000 potential Nemesis candidates. Perhaps by the latest discovery, more analyses of the movement of these candidate stars will occur. Giant Nemesis candidate HD 107914 / HIP 60503 for the perforation of Oort cloud (Some of the font code for the symbols didn't translate so for those of you geeks who care you'll need to see the link for the text corrections.)
Looks like the star spent about 30,000 years within the "solar system," as broadly defined. The primary author of the referenced article has a set of FAQs here: http://www.pas.rochester.edu/~emamajek/flyby.html
OK, now this naysay goes too far. It is not analogous to your dice example, not even close. Hypothesizing galactic objects pass close to the Oort Cloud and finding one that actually did are two different things.
Yep. Observation is a key part of the scientific process. It is all well and good to have hypotheses, or make models, etc., but being able to take observational data to verify that something in those hypotheses actually happened is significant.
Excellent link. Thanks for the find. (Last bold is mine) Of course, the BBC article's headline was mild compared to more common ones like this referenced one:
How? Stars move with relation to one another. There is a galaxy filled with stars. The hypothesis is they pass close to each other sometimes. We found one that did in our solar system so its special for some reason? Its not like the hypothesis was something that required discrete evidence to be believable. Its like saying "We know ducks fly so we hypothesize its possible for them to fly into a plane engine. "We found one that did, now we know ducks can fly into plane engines!!! Also seventy people died from the plane crash."
Whoa! Yes, hypotheses do need evidence, not just 'it's logical'. More than one logical hypotheses have not borne fruit.
You're not thinking about this in terms of how science works. There are all kinds of hypotheses that may be "believable," but until there is observational evidence there is always a question, scientifically. Observational data to support a hypothesis is a big deal.
It does make one wonder what life is like for those beings who live in more congested areas of the galaxy.
In addition, @HelloImRex, the Nemesis hypothesis is that a star has passed near the Oort cloud recent enough we should be able to find it, (or them). And another question is, does one star return on a regular basis or are the mass extinctions random events with coincidental regularity? So finding the actual star will be a big deal. This is one more step closer to finding that object. And I've already said my thread title was premature, but then I did add the ???
@Wreybies have you ever read The Dragon's Egg, by Dr. Robert Forward? The novel centers on an neutron star that is moving close enough to earth to be observable and allow communications. There are inhabitants of the star who, because of the properties of the star, live out lives and evolve at rates orders of magnitude faster than humans on earth. The book takes place over the course of a number of months, I believe, and from when the humans first spot the star and decide to send an expedition, to when the humans actually arrive, the inhabitants of the star evolve from a pre-agricultural civilization to an advanced society. Interesting book speculating on how life may differ in different celestial environments. And one thing that makes it stand out from a lot of books is the amount of rigor with respect to physics.
Evidence for a hypothesis doesn't really say that much. Its much more informative when you discover something that is contrary to a hypothesis. I'll give an example. Hypothesis: Cars that hit an object will cause an impact. Results: A car hit a tree!!! A car hit a boat! A car hit a pedestrian! A car hit a koala... A car hit a hammock. A car hit a eucalyptus tree... A car hit another car... A car hit a submarine....... A car hit a tortoise, but the tortoise was next to my house!!! This is significant!!! Now if a car goes straight through something without causing any evidence of an impact that is much more interesting and refutes the original hypothesis.
Its that there is a star in orbit of the Oort cloud that influences a cycle of mass extinctions. A star passing 70 thousand years ago doesn't correlate with any mass extinction event and is a one time thing. There is no relationship.
This makes no sense. If you have a hypothesis that says X, and then you have observational evidence confirming X, that says a lot about the hypothesis. Prior to this finding, we had years of data that failed to show a star passing this close to us. That data didn't lead to any conclusion.
Sorry, @HelloImRex, I can't even relate to your logic. Try these, (I'm more familiar with failed medical hypotheses): It was hypothesized that excess gastric acid secretion caused ulcers. It was logical and believed for years to be the correct hypothesis. Except it turned out to be wrong. Because tonsils were the common site of strep throat infection, it was logical that removing them would decrease recurrent throat infections. Except that turned out to be wrong. We were wrong about the 'bad air' hypothesis of diseases like cholera and malaria. The scientific process is to observe, form hypotheses, test them, then repeat the tests to increase certainty.
Never heard of it. May have to hunt it down as Harrison's Empty Space (#3 after Light and Nova Swing) is leaving me a little nonplussed. So far it feels like a rehash of the prior two novels, plus Harrison is one to latch on to a certain vocab list and use the bajinkies out of it. I mean, really, how many things not performing reentry into an atmosphere can be described as ablated. Far is Harrison is concerned, the answer seems to be: at least one thing for every two pages.
The hypothesis is that because stars move one could have moved close to us. That isn't even how a general hypothesis works. Most work by saying "Because of x, y will always happen.". Then you find evidence of this, but as soon as one piece of data suggests something different you have to amend the hypothesis. X happens all over the place, so X could have happened in this place too. The evidence doesn't really mean anything when there is no implication related to X happening. If you call this a hypothesis I hypothesize that since a pair of dice can roll two sixes that sometime in the last year Obama rolled two sixes with a pair of dice. You didn't need evidence of the hypothesis to know that it could have happened because the mechanic behind dice rolling was already known. With the stomach ulcer example the hypothesis was directed toward a cause. It wasn't. "Since people can get stomach ulcers and we know how frequent they are I hypothesize at least one of the presidents had a stomach ulcer at one point."
It's considered a classic of hard science fiction. One reviewed described it as a textbook on neutron stars cleverly disguised as a novel. I thought that was a bit much, though. I remember enjoying it when I read it years ago, as much for the ideas in it as anything. I haven't read Empty Space yet, but it is on my list.
