Topic Tuesday #53 2013/07/23 - "Climate Cycles"

If we are to be skeptical and honest with ourselves about the world we live in, we need facts. LOTS of facts.
I am going to highlight some facts that are not often brought to the table when discussing climate change. I am only going to present the items. In general this is all from the field of applied mathematics and earth sciences known as Geodesy.

Earth's Path

The earth's orbit is not circular. It is elliptical, an oval.
We are closest to the Sun around January at a distance of 147,098,290 kilometres (91,402,640 mi) [0.98329134 AU] and farthest from the Sun around July at 152,098,232 kilometres (94,509,460 mi) [1.01671388 AU] Nearly 3 million miles difference.

The reason we have seasons is due to the Earth's axial tilt. The Earth wobbles a little. Over 41,000 years, the tilt fluctuates from 22 to 24.4. The average tilt today is about 23.5 degrees, roughly in the middle of a diminishing tilt trend. The more perpendicular the planet to the Sun, the more uniform the heating, and the higher the average temperatures. Based on the current figures, the Earth will be at 22.6 degrees tilt in 8,800 years.

Rotation (green), precession (blue) and nutation in obliquity (red)

The tilt undergoes an irregular motion known as nutation with a period of 18.6 years.
The orientation (rather than the angle)of the axis changes over time following a circle with a cycle of 25,800 years. This is the determining factor between sidereal and tropical years.
These changes are known as Axial precession.

The poles also migrate (Polar Motion). The collective term for all the factors in its movement is "quasiperiodic motion". There are several periodic affects. A circular motion occurs annually while others have longer periods, one of which is the Chandler wobble with a 14 year cycle but a period of 435 days.
The rotational velocity along the axis is variable. The phenomenon is known as the length-of-day variation. Think of an ice skater, spinning with their arms in tight and then to stop they put their arms out. As the earth bulges out in the middle more, be it from continental drift or from glacier melt raising the sea level, the planet will spin slower, increasing the day.

Temporal Changes - Surface changes, and things over time.

Plate Tectonics
Episodic fault-line events.
Tidal shifts
Postglacial land uplift
Temperature cycles: Ice age

Human interaction

Material extraction
Material relocation
Teraforming
Directed phase change of material. Fuel consumption

There are thousands, if not millions, of data points that go into climate science, and I don't want to blowup a single thread with all of them. Some of them, nay, most of them are deserving of a day in the sun and I will revisit them in time. Knowledge of your current situation is not enough to determine any kind of model for the future. We must study the rich past.
I hope that this has opened your eyes a little to the nature of our home planet. It is ever changing. Dynamic. Chaotic. Fragile- but only for us. It will go on spinning. The thing to remember is perspective.

"Let's be clear. The planet is not in jeopardy. We are in jeopardy. We haven't got the power to destroy the planet - or to save it. But we might have the power to save ourselves." - Ian Malcom - Jurassic Park

Topic Tuesday #47 2013/06/11 - "Big Brother / Big Data"

Orwell would be pointing a malnourished finger at all of us and chanting, "I told you so".
I don't go into the dystopian conspiracy theories, but as they are part of our culture, they still must be examined. Today the magnifying glass is on "Big Data". You may have heard the term, and if you haven't, you will.
Wikipedia summarized it thusly:
Big data is a collection of data sets so large and complex that it becomes difficult to process using on-hand database management tools or traditional data processing applications. The challenges include capture, curation, storage, search, sharing, transfer, analysis, and visualization. The trend to larger data sets is due to the additional information derivable from analysis of a single large set of related data, as compared to separate smaller sets with the same total amount of data, allowing correlations to be found to "spot business trends, determine the quality of research, prevent diseases, link legal citations, combat crime, and determine real-time roadway traffic conditions.

Big Data is just that, BIG. Veritable truckloads of data available on demand and manipulatable to yield a variety of correlations. It's enough to give you the heebie-jeebies, but honestly, it is unavoidable.
Big Data is a side effect of our increasingly technological society. We have devices that generate information that can be captured and logged. Most of it is innocuous. Like temperatures, wind speed, and rainfall.
We take weather measurements every few seconds (this would be a data set, like a spreadsheet) in thousands of weather stations all over the world (a larger data group, a collection of spreadsheets). Now imagine that you have all this information collected from all the weather stations all over, and now you can see patterns. With patterns you can make predictions. Voila, you have a rudimentary weather model and can start to predict storm patterns.
Now extrapolate that out further. Do you have a credit card? Congratulations you have your own data set of purchasing patterns! This information is stored and used to determine fraud patterns. If suddenly you are outside your normal spending patterns or regions, you may be flagged with a fraud alert, keeping you safe. The dark side of the credit card industry is they have a tendency to sell/share that information with marketers and even law enforcement. In this way your habits become a recognizable pattern. Patterns can be identified, and some are as unique as a finger print.
It is safe to assume that if your have a device that generates a loggable data set, you can be sure someone somewhere is collecting it, and someone else wants it for some reason. Some will want to make life easier for you, others for themselves. Some will profit from it, and others will suffer. And I haven't even got into facial recognition!