John C. Baez's Blog, page 85

El Nino Project (Part 4)

As the first big step in our El Niño prediction project, Graham Jones replicated the paper by Ludescher et al that I explained last time. Let’s see how this works!

Graham did it using R, a programming language that’s good for statistics. If you prefer another language, go ahead and write software for that… and let us know! We can add it to our repository.

Today I’ll explain this stuff to people who know their way around computers. But I’m not one of those people! So, next time I’ll explain the...

Entropy and Information in Biological Systems (Part 2)

John Harte, Marc Harper and I are running a workshop! Now you can apply here to attend:

• Information and entropy in biological systems, National Institute for Mathematical and Biological Synthesis, Knoxville Tennesee, Wednesday-Friday, 8-10 April 2015.

Click the link, read the stuff and scroll down to “CLICK HERE” to apply. The deadline is 12 November 2014.

Financial support for travel, meals, and lodging is available for workshop attendees who need it. We will choose among the applicants and...

El Niño Project (Part 3)

In February, this paper claimed there’s a 75% chance the next El Niño will arrive by the end of 2014:

• Josef Ludescher, Avi Gozolchiani, Mikhail I. Bogachev, Armin Bunde, Shlomo Havlin, and Hans Joachim Schellnhuber, [Very early warning of next El Niño, Proceedings of the National Academy of Sciences, February 2014. (Click title for free version, journal name for official version.)

Since it was published in a reputable journal, it created a big stir! Being able to predict an El Niño more than...

Chemical Reaction Network Talks

A while ago I blogged about David Soloveichik’s talk at this workshop:

• Programming with Chemical Reaction Networks: Mathematical Foundations, Banff International Research Station, 8-13 June 2014.

Now the slides for his talk are available:

• David Soloveichik, U.C. San Francisco, The computational power of chemical reaction networks.

And now I’d like to tell you about three more talks!

The first two are about ways one chemical reaction network can simulate another. This is important for a couple...

El Niño Project (Part 2)

Before we dive into the exciting world of El Niño prediction, and ways that you can help, let’s have a very very basic crash course on the physics of El Niño.

El Niños are still rather mysterious. But that doesn’t mean we should ignore what the experts know, or suspect.

The basics

Winds called trade winds blow west across the tropical Pacific, from the Americas to Asia. During La Niña years, water at the ocean’s surface moves along with the wind, warming up in the sunlight as it travels. So,...

El Niño Project (Part 1)

A bunch of Azimuth Project members like to program, so the Azimuth Code Project has been around for a while… but now it’s taken a new turn! We’re trying to understand and predict the climate phenomenon known as El Niño.

Why? Several reasons:

• It’s the biggest source of variability in the Earth’s climate on times scales between a year and a decade. It causes weather disturbances in many regions, especially near the Pacific Ocean. The last really big one happened in 1997-1998, and we’re waiting...

Wind Power and the Smart Grid

Electric power companies complain about wind power because it’s intermittent: if suddenly the wind stops, they have to bring in other sources of power.

This is no big deal if we only use a little wind. Across the US, wind now supplies 4% of electric power; even in Germany it’s just 8%. The problem starts if we use a lot of wind. If we’re not careful, we’ll need big fossil-fuel-powered electric plants when the wind stops. And these need to be turned on, ready to pick up the slack at a moment’s...

The Computational Power of Chemical Reaction Networks

I’m at this workshop:

• Programming with Chemical Reaction Networks: Mathematical Foundations, Banff International Research Station, 8-13 June 2014.

Luca Cardelli wrote about computation with chemical reactions in Part 26 of the network theory series here on this blog. So, it’s nice to meet him and many other researchers, learn more, and try to solve some problems together!

The first tutorial was this:

• David Soloveichik, U.C. San Francisco, The computational power of chemical reaction networks....

Warming Slowdown? (Part 2)

guest post by Jan Galkowski

5. Trends Are Tricky

Trends as a concept are easy. But trends as objective measures are slippery. Consider the Keeling Curve, the record of atmospheric carbon dioxide concentration first begun by Charles Keeling in the 1950s and continued in the face of great obstacles. This curve is reproduced in Figure 8, and there presented in its original, and then decomposed into three parts, an annual sinusoidal variation, a linear trend, and a stochastic remainder.

Figure 8. K...

Warming Slowdown? (Part 1)

guest post by Jan Galkowski

1. How Heat Flows and Why It Matters

Is there something missing in the recent climate temperature record?

Heat is most often experienced as energy density, related to temperature. While technically temperature is only meaningful for a body in thermal equilibrium, temperature is the operational definition of heat content, both in daily life and as a scientific measurement, whether at a point or averaged. For the present discussion, it is taken as given that increasing...