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Changes in Earth's Orbit Linked to Extinctions
Josh Fink writes "A group of Dutch Scientists have recently released a study stating that they have found that changes in Earth's orbit around the sun are linked to mammal extinctions. From the article: '"Extinctions in rodent species occur in pulses which are spaced by intervals controlled by astronomical variations and their effects on climate change..." The cycles are associated with lower temperatures, changes in precipitation, habitats, vegetation and food availability which are the main factors influencing the extinction peaks, the study published in the journal Nature said.' So on top of worrying about global warming, it seems we should also worry about the physics that govern the orbit of Earth around the sun. Too bad we don't have a way of keeping the Earth in the same orbit/on the same axis of rotation."
The dinosaurs died because you touch yourself at night. Family Guy told me so.
Is causing a wobble in the earth's orbit and causing global warming. Now where is my Nobel prize?
Bush cut funding for Chuck Norris?
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"Outlook not so good." That magic 8-ball knows everything! I'll ask about Exchange Server next.
Too bad we don't have a way of keeping the Earth in the same orbit/on the same axis of rotation.
You sir are shortsighted. Find someone to blame, add it to the party platform (either one, it doesn't matter) and then fund raise on it. Global Wobbling must be stopped!! We can stop it!!! It won't be stopped if party X get's/keeps control of Congress!!! The time to act is now!!
Please click here to donate 25, 50, 100, 1000 dollars to STOP GLOBAL WOBBLING. You will receive two complimentary pamphlets entitled "The Wobble, the Planet, and You" and "Why is Galileo weeping?". Both are packed with earth-shattering information to help you spread the news of this new threat to our precious freedoms and way of life.
It doesn't account for the massive extinctions such as the Permian. The arrangement of the continents also very likely either exacerbates or minimizes the effects of orbital variations. They also only studied a specific region in Spain (not to mention rodents in particular) which may have been especially prone to subtle climate changes. They need to study a wider geographic and species range.
It is by the juice of the coffee bean that thoughts acquire speed, the teeth acquire stains. The stains become a warning
Even if we could affect a change in the earth's orbit around the sun, who's to say if that is a good thing? Might that not be akin to preventing all forest fires? Controlled burns are our way of preventing some large/catastrophic forest fires and lightning strikes are nature's way of doing it. What makes us think the "wobble" in our orbit isn't causing cyclical "refresh" events? No, I'm not suggesting some diety is controlling things or that ZOMG WE R AL GOING 2 DIE or anything like that. Just saying we might not yet comprehend the consequences of making this "fix" change. Hell, we are still unable to predict the weather with any certainty more than a day or two out. /shrug
Here's a quick link to some other studies: http://earthobservatory.nasa.gov/Study/Paleoclimat ology_Evidence/
Axis of Evil, Axis of Rotation, THEY ALL MUST GO!
We don't have animals in our climate model, but if you'd like to see how orbit effects climate, you can do so yourself.
The EdGCM project has wrapped a NASA GCM in a graphical interface. You can double-click to install, and if you'd like to turn the sun down a few percent or change the orbit, there are checkboxes and sliders. Press play, wait a while (hours to a day or so depending on your computer), and you can look at the results...
Disclaimer: I'm the developer.
Space and Computers.
http://en.wikipedia.org/wiki/Tipping_point
Not saying this necessarily applies; just pointing out that just because a process may be gradual does not mean that its consequences can't be sudden.
Due to circumstances beyond my control, I am master of my fate and captain of my soul.
The whole tone of this /. post freaked me out. There's no way for there to be 'irregularities' in the Earth's orbit without something with both really high mass and really high velocity interacting with the earth or the sun.
So I read up on Milankovich cycles, and it turns out it's just precession. It's perfectly regular, it's just that in the case of something the size & slow angular velocity of the earth, it takes a really long time to change.
When you spin a top, you can see the axis of spin describe a circle. This is precession.
Likewise as the Earth rotates, there is precession. Also, as the earth orbits the sun, there is precession. These have cycles on the order of tens of thousands of years. Both can affect the climate by changing the angle of sunlight. There are cycles on the order of millions of years long in which the two effects both affect the climate the same way, and so produce a bigger net effect.
I guess wobble is an accurate term, except that to me it implies something irregular. In a system as big and isolated as the Earth's orbit around the Sun, or the Earth's rotation, momentum is king, and very little could cause an irregular change. These changes are just precession, and they're perfectly regular.
I am not a physicist, but I do have a Bachelor of Science in Physics.
If a job's not worth doing, it's not worth doing right.
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"...So on top of worrying about global warming, it seems we should also worry about the physics that govern the orbit of Earth around the sun. Too bad we don't have a way of keeping the Earth in the same orbit/on the same axis of rotation."
/ earth_move_010207.html
Yes, we have! And it's very interesting indeed!
http://www.space.com/scienceastronomy/planetearth
A link to the paper: Korycansky, D. G.; Laughlin, Gregory; Adams, Fred C. Astronomical engineering: a strategy for modifying planetary orbits. Astrophys.Space Sci. 275 (2001) 349-366
http://arxiv.org/abs/astro-ph/0102126
Abstract:
"The Sun's gradual brightening will seriously compromise the Earth's biosphere within ~ 1E9 years. If Earth's orbit migrates outward, however, the biosphere could remain intact over the entire main-sequence lifetime of the Sun. In this paper, we explore the feasibility of engineering such a migration over a long time period. The basic mechanism uses gravitational assists to (in effect) transfer orbital energy from Jupiter to the Earth, and thereby enlarges the orbital radius of Earth. This transfer is accomplished by a suitable intermediate body, either a Kuiper Belt object or a main belt asteroid. The object first encounters Earth during an inward pass on its initial highly elliptical orbit of large (~ 300 AU) semimajor axis. The encounter transfers energy from the object to the Earth in standard gravity-assist fashion by passing close to the leading limb of the planet. The resulting outbound trajectory of the object must cross the orbit of Jupiter; with proper timing, the outbound object encounters Jupiter and picks up the energy it lost to Earth. With small corrections to the trajectory, or additional planetary encounters (e.g., with Saturn), the object can repeat this process over many encounters. To maintain its present flux of solar energy, the Earth must experience roughly one encounter every 6000 years (for an object mass of 1E22 g). We develop the details of this scheme and discuss its ramifications."
That's absurd. There's no "areas near the equator" that are too hot for humans to survive. There's no such "area" anywhere on earth. Daily temps of 120+ are easily survivable - Las Vegas sees that regularly. See, humans have these things called "sweat glands". All they need is water and they can survive the heat.
But what if there's no water, you say? Well then, the problem isn't the heat.
ah, it's amazing how so many conspiracy theories have been brought to my attention through slashdot postings. Apparently, ithis particular linked in with Christian eschatology or some such nonsense.
Might I point out that the Romans used an especially inaccurate calendar, and it was not until 46 BCE that the somewhat more familiar Julian system was adopted?
360 happens to be an easy number to use. It's not especially accurate, but correcting the error requires some knowledge of astronomy, as well a certain amount of political power. Now, it may be that a number of civilizations adopted a 365 day year at approximately the same time. Perhaps some of them were trading partners.