# Milankovitch Cycles: Find the 53,300,000 Year Cycle

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• g48dd
In summary: I have more questions but I need to study the info I have gotten, thank you again.In summary, the conversation discusses the concept of Milankovitch cycles and the idea of three clocks representing different cycles that move at different speeds. The speaker is trying to find a cycle where all three clocks return to their starting point at the same time. They use a spreadsheet to calculate the earliest occurrence of this and suggest researching the concept of least common multiple. However, it is noted that due to the complexity of various factors, it is unlikely for all three cycles to align perfectly. The conversation also touches on other potential influences on these cycles, such as gravitational waves and the movement of the Milky Way Galaxy.
g48dd
TL;DR Summary
Determine the time period it takes for three different cycles to intersect at the same time.
I wanted to look at Milankovitch cycles and each cycle like a clock and that would mean we have 3 clocks each one moving at a different speed. We have a 100,000 year clock (Eccentricity), a 41,000 year clock (Obliquity), a 26,000 year clock (Procession). I want to start all the clocks at the same time. I am looking for a cycle of when all three clocks are once again at their starting point at the exact same time. I don’t know if there is a name for that cycle. I didn't think this would be that difficult to figure out; I’m not great with math but OK with a spreadsheet given some time. I thought that sense Eccentricity is the longest cycle why not just find where Obliquity and Procession divide into 100,000 years evenly at the same time. I am assuming this would mark the end of one full Milankovitch cycle and the beginning of the next. I used a spreadsheet for this because I have no idea how to write an equation for it. Excel will only work with so many digits, so I had to reduce 100,000 to 10, 41,000 to 4.1, and 26000 to 2.6 and then when I get my final number, I multiply by 10^4. That said the earliest occurrence of both Obliquity and Procession dividing in evenly at the same time was when Eccentricity was on its 5,330th completed cycle. So 5330 x 10^4 would be 53,300,000 years. I have uploaded a screen shot of my Excel spreadsheet and I have collapsed hundreds of rows. Column A 1-1,000,000, Column B 10*A1 carried down, Column C is the result in B1/4.1 and Column D is the result in B1/2.6 and I rounded to 4 decimals. At line 533 they all lined up. I then multiplied 5330 by 10^4 and got 53,300,000 years. So my questions are; would this represent a full Milankovitch cycle? Is there a name for that? Am I even thinking about this correctly and if not, could you suggest some reading or a video. Thank You

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You could Google "least common multiple".

But without a good reason to believe that the cycle times have rational ratios there is no good reason to expect a least common multiple to exist.

mfb
53,300,000 years is indeed the least common multiple, but this is a purely mathematical result without physical relevance. It corresponds to over 2000 precession cycles. If that cycle time is not 26,000 but 25,995 or 26,005 years then the pattern will be off by half a cycle in 53 million years. I'm sure these three cycles are not all nice multiples of 1000 years. Even worse, their period might change over such a long timescale.

You get pretty close to a repetition after just 207,000 years, with 2.1 periods of the eccentricity, 5.0 periods of the obliquity and 8.0 periods of the precession.

FactChecker
Thank you, yes I get that actually Procession calculations say between 19,000 to 26,000 years. So obviously by only choosing 26,000 you that works out but Procession isn't always 26k. There are to many variables to actually say a complete cycle is 53,300,000. In truth I am thinking that there is never a time when all three cycles would be back to the same starting point. None of this takes into affect the Sun and how that influences things nor, magnetic fields? I don't know how things happening far, far away affect indirectly... that's why I am here to try and understand what we do know, and what we think might be possible. Thank you for your comment ... oh yes I did go look up Lcm and I worked that out on my own 2x2x5x5x41x13 and that is 53,300,000. so I learned something and that's cool.

If you look closely enough then you'll never get an exact repetition of orbital parameters of Earth. You'll get many cases where the parameters are very similar, however.

Precession, by the way. Procession is a bunch of people walking around.

lol glad you pointed that not paying attention, thank you. I became fixed on this three clock thing. I do realize that there are so many things that influence these three paths that I felt there would be no exact return to the same path. That was cool though because it got me starting to think about what else could have an affect on these cycles, can gravitational waves, movement of the Milky Way Galaxy. It just makes want to understand more about how the universe works. Thank you for your comment.

Gravitational waves and everything outside the Solar System don't matter, but the Solar System has enough objects to create interesting dynamics.

Thank you tells me where to look.

## 1. What are Milankovitch cycles?

Milankovitch cycles are long-term variations in Earth's orbit and tilt that affect the amount and distribution of sunlight reaching the Earth's surface. These cycles are named after Serbian scientist Milutin Milankovitch, who first proposed the idea in the early 20th century.

## 2. What is the 53,300,000 year cycle in Milankovitch cycles?

The 53,300,000 year cycle, also known as the "long eccentricity cycle," refers to the gradual change in the shape of Earth's orbit from nearly circular to slightly elliptical and back again. This cycle has a period of approximately 53.3 million years and is thought to impact the amount of solar radiation reaching Earth's surface.

## 3. What evidence supports the existence of the 53,300,000 year cycle?

Geological evidence, such as sediment cores and isotopic ratios in rocks, have been used to reconstruct the past changes in Earth's orbit and tilt. These records show a consistent pattern of the 53,300,000 year cycle over the past 500 million years. Additionally, mathematical models and simulations have also been used to confirm the existence of this cycle.

## 4. How do Milankovitch cycles affect the Earth's climate?

The changes in Earth's orbit and tilt caused by Milankovitch cycles can impact the amount and distribution of solar radiation reaching Earth's surface. This, in turn, can affect the amount of heat and energy available to drive the Earth's climate. For example, when Earth's orbit is more elliptical, there is a greater difference in solar radiation between the closest and farthest points from the sun, leading to more extreme seasonal variations in temperature.

## 5. Are Milankovitch cycles responsible for current climate change?

No, current climate change is primarily driven by human activities, such as the burning of fossil fuels and deforestation, which have increased the amount of greenhouse gases in the atmosphere. However, Milankovitch cycles can influence the Earth's climate over long periods of time, and may play a role in the Earth's natural cycles of warming and cooling.

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