# The Shape of Earth's Orbit

Discussion in 'Astronomy, Exobiology, & Cosmology' started by KilljoyKlown, Apr 25, 2013.

1. ### KilljoyKlownWhateverValued Senior Member

Messages:
6,493
I came across this topic and was wondering, exactly where in this 100,000 year cycle are we at this time? And how might this be affecting our current weather?

3. ### youreyesamorphous oceanValued Senior Member

Messages:
2,830
http://en.wikipedia.org/wiki/Milankovitch_cycles

If the relationship between eccentricity of the orbit and time of said cycle is linear, than:
e @ 0.005 corresponds at beginning of cycle or 0th year, e @ 0.028 corresponds to end of cycle or 100,000th year.
0.028-0.005=0.023 variation. 0.017/(0.23/100)=7.39130434783 % of time has passed since zeroth year. 0.0739*100,000=7391th year, from zeroth year. So basically we are just in beginning of the cycle.

And beginning of said cycle was 2013 A.D - 7391 years = 5378 B.C, otherwise the birth of civilization, Mesopotamia as well as early rise of Norte-Chico civilization.

Last edited: Apr 25, 2013

5. ### KilljoyKlownWhateverValued Senior Member

Messages:
6,493
Okay so far so good. I'm assuming that year 0 is when the orbit is closest to an actual circle and that year 50,000 is the most elliptical that it gets. Please correct me if that's wrong. Now I'm also interested in the other orbital/planetary cycles Milankovitch worked on. It boggles my mind when I try picture three different length cycles that all have their own input into our weather. I assume they have both best and worst case scenarios depending on how those cycles are interacting with eachother. But I haven't found it yet and would be interested to know how bad or good our current situation is when human made global warming is factored in to the equation?

and

The Wobble of Earth's Axis

7. ### OnlyMeValued Senior Member

Messages:
3,914
It boggles a lot of minds including some that work directly on or with global weather..., ever watch a weather report.., and then go outside?

8. ### youreyesamorphous oceanValued Senior Member

Messages:
2,830
I was under impression that the cycle is 100,000 years long and that the maximum eccentricity occurs at 100,000th year. Correct me if I am wrong...the wiki site mentioned an even bigger cycle there too...

Also whether we completely nuke our planet or slowly increase our rate of green house gases emission into atmosphere, does not affect the actual eccentricity of our planet against the sun, what changes through those 100 millenia are the locations where the summers and winter seasons occur, and also increase in change of the season (shorter fall and spring).

Visualization of Milankovitch cycles:

http://web.mit.edu/unity3d/milankovitch/

9. ### KilljoyKlownWhateverValued Senior Member

Messages:
6,493
The complete cycle is 100,000 years, so at 50,000 years it will start back to getting more circular again. I found another chart which might be closer to the true distances. One of the things the article commented on were that sometimes all cycles can line up in a bad way for the Earth and we have a major ice age. Has anyone started a topic on how all the people on Earth would deal with an ice age? Does anyone believe we could stop an ice age from happening?

10. ### KilljoyKlownWhateverValued Senior Member

Messages:
6,493
After doing the install that was a very good inter active display. However, I'm not sure those graphs mean much to me without a lot of study on that subject. I was hoping for someone who was already knowledgeable on the subject could comment about it in simple easy to understand terms.

11. ### youreyesamorphous oceanValued Senior Member

Messages:
2,830
if you scroll the time along the shown variations of eccentricity, notice the temperatures at the lowest eccentricity value and highest eccentricity value...basically no actual change.

12. ### KilljoyKlownWhateverValued Senior Member

Messages:
6,493
The article did say that mostly the different cycles do cancel eachother out. But when you are talking many millions of years it is possible that the cycles could line up in a way that cause big problems. Even our solar system has it's orbital cycles around our galaxy. Who can say for sure what causes our ice ages, but I'm betting the next one is not going to be a very good experience for whatever people are living on the Earth at the time.

13. ### dragon0788Registered Member

Messages:
11
Gif is explain everything

14. ### bolonnyRegistered Member

Messages:
16
look up time elapses of the sun and you will find interesting videos that show the true orbit and woble just by looking at the path the sun follows ..its like a cursive lower case L....ed lindiscalnin<coral castle builder>
made a pretty impressive sun dial

15. ### Robittybob1BannedBanned

Messages:
4,199
I was thinking it could be like a train going around a corner, well the older ones used to press up against the rails and then slide across and later it repeats the rocking motion till it gets around the corner.
So as the Sun drags the Earth around the galaxy I would say the Earth is trying to go straight till the pressure builds up. So the rhythm starts up.