What I mean is that there are direct and measureable forces that affect the Earth - Internal geological forces, the forces exerted by the Sun and the Moon - all of which combine to bring about things such as Tides, weather systems, atmosphere, etc. But is it possible that other planets in the Solar System (specifically Jupiter and the outer Gas Giants) have any influence over how the Ecosystem and Environment on Earth varies over time? For that matter, does the Earth's position in respect to where it is in the Milky Way Galaxy (and by extension the Super Galaxy groups) and the consequent path through space that the Earth travels as part of these groups have any bearing on what happens here on Earth? I don't think we can fully understand Climate change and other aspects of Earth's characteristics without considering Earth's ancient journey through Space. My line of thinking is that perhaps these effects are so marginal (as far as we can measure right now) that we can't really detect anything without scrutinizing patterns over long periods of time. Anyone have any ideas?
The fact that the extinction-level events happen very close to a 62 million year cycle (http://sfgate.com/cgi-bin/article.cgi?f=/c/a/2005/03/10/MNGFIBN6PO1.DTL) suggests extra-solar system causes.
There are suggestions that some changes over millions of years might be caused by the solar system passing through regions of high concentrations of dust. Or you could easily imagine a nearby supernova giving off enough radiation to damage the Earths ecosystem, although I cant remember if they have found any candidate stars. But as for climate change in the past few thousand years, theres nothing to suggest extrasolar causes.
Or it could just be probability at work. Well, Jupiter does affect the earth indirectly, by "sucking in" asteroids and comets which otherwise would be whizzing aound, posing a danger to Earth.
do you see the stars at night? do you see the light of venus, brighter than any other in the sky save for the moon and the sun and the occasional comet? do you see meteors falling to the earth? these are extra-solar forces affecting our planet and i am sure that there are even stronger forces that we are not able to see with the naked eye.
Most experts consider the cyclical hypothesis of mass extnctions rubbish, it requires to much special pleading and fudging of the kill curve graph. We find that one mass extinction was caused by an impact (and I don't the impact was the ONLY cause of the K/T extinction, volcanism and a rapid drop in sea level were also to blame, IMO) and people try to blame all mass extinctions on impacts. Please Register or Log in to view the hidden image! The cyclical hypothesis is just another spinoff of the impactor fad. There are many good-sized impact craters (such as the one under Cheasapeake bay) that are totally unrelated to an extinction event.
I rember reading an article saying that both the Ordovician mass extinction and the Ordovician Ice Age were caused by a gamma ray burst.
Without researching it, comets enter our solar system from other solar systems at hundred year intervals. How could this not affect us?
I think that our solar system is at just the right distance from galactic center to be rotating at the same radial velocity as the galaxy itself. This means that we do not drift through a radically different galactic environment.
We are constantly and continuously being affected by background radiation and the minute affects of gravity from other solar systems.
There are an awful lot of forces working in the solar system. The earths orbit is modified by many of them, causing a precession of the equinoxes, the earth axis describing a cone with a period of about 26,000 years. It's caused by assymmetric torque forces due to gravity of sun and moon. But there is also the precession of the perihelion/aphelion (closest - farthest to the sun) with a period of 19-22,000 years. The reason that they are not the same is the gravitation of Jupiter, modifying the orbit of the earth ever so slightly. Then the axial tilt of the Earth is varying with a period of 41,000 years due a complicated interaction of forces and momentums. Next the eccentricity of the earth also changes with a period of 400,000 years and not 100,000 years as you can google easily using "milankovitch cycles". The reason for that widespread error is a major cyclicity in the Earth history seen in the ice cores and the oceanic sediment cores. There is actually a very weak, negligible component in the eccentricity cycle of about 95,000 years but far too weak to have anything to do with that, whereas the strongest 400,000year cycle cannot be traced back in the earth "files" at all. So the search for the cause of the 100,000 cycle with seems to be governing ice ages is ongoing with some very interesting developments lately on the ocean bottom. I think that we have to face some surpises from the most inner parts of the Earth reacting -non lineair- on all those forces as well But the cycles of the sun may be even more important for our current climate. It is thought that the gravity of the planets also cause tensions and torsions in the sun with several periods. The sunspot cycles of 11 and 22 years are well known but there is also a strong complicated 166 years “Gleisberg” cycle superimposed. One well known minimum in that cycle was the Maunder minimum (1670AD) which correlates with the coldest spot of the little ice age. Courtesy to Edufer we have this prediction of late Dr Landscheidt: Please Register or Log in to view the hidden image! Source So we expect 2030 to be the height of a next little age. But you wont find this in the climate models. So we don’t have to wait too long to see how true global warming is.
