Sequiturs

Let’s take a break from our regular programming (such as it is), and introduce one of my favorite new music albums in years. In September, Scottish “post-rock” artists Mogwai released their sixth studio album, The Hawk is Howling. It is available in its entirety at their Myspace page. (I think Myspace is good for exactly one thing: distributing legal free music.) I encourage you, of course, to support the artists with a purchase if you like the album. I’ll add that Mogwai is my favorite band in the world, so this “review” is less an effort at critical objectivity than at at encouraging everyone to go listen to them by describing the album.

While there are no drastic departures from the melodic, brooding, hopeful sound of previous Mogwai works, there are a few minor changes that add up. First of all, The Hawk is Howling contains no vocal elements at all. Also missing are most of the electronic dubbing and sampling of previous works, resulting in some of their most organic tracks to date. Perhaps most importantly, this album seems much more direct than their other offerings. Each song, excepting perhaps “Batcat,” has an immediately apparent, gripping melody that could be played by one or two peole on keyboards without losing too much vitality. These tunes are relatively simple and memorable, compared with 2001’s Rock Action or even 2006’s Mr. Beast. There’s plenty of somber, crystalline beauty here, but there’s also a newfound willingness to write tunes you can hum or stomp along to. The melodies are as sophisticated as ever, but a little more aggressive and less complex, without losing depth.

There’s also quite a lot of stylistic variety on this album. The strangely named opener “I’m Jim Morrison I’m Dead,” with it’s shimmering piano and angular guitars, sounds like what might happen if Mr. Spock wrote a Klingon opera. On the other hand, “The Sun Smells Too Loud” is upbeat, even danceable, conveying a sense of enjoyment with the emotive force most artists in this genre sadly reserve for melancholy. “Scotland’s Shame” is a straightforward, driving anthem that will immediately setup housekeeping in your hippocampus. “Danphe and the Brain” and “Thank You Space Expert” are catchy numbers that sound like somebody bouncing wordless poems off the sky. “The Precipice” is the thing you jump off of at the end, wondering if you can fly.

One thing that sets Mogwai apart from most of their post-rock brethren/followers is that their hard rock roots are deep and healthy. With the barely-bridled malice of tracks like “Batcat” and “I Love You, I’m Going to Blow Up Your School,” Mogwai not only invite the space invasion, but threaten to beat it back as well. At once meditative and gripping, The Hawk is Howling has as much in common with Tool’s Lateralus as with the latest from Explosions In The Sky or GY!BE. Imagine your favorite hard rock band had a spiritual epiphany and spent a few years in a secluded monastery; Mogwai is what they’d sound like when they came back down the mountainside and found you worshiping a golden calf.

This may not be everyone’s cup of tea, but I think it is post-rock, and indeed music, at its very best. The world is a better place with The Hawk is Howling in it.

Should the government dig another giant hole?

The Onion asks the tough questions.

P.J. O’Rourke is irate–and, as always, hilarious. I think he has the state of modern conservatism pretty much pegged.

Wherever you go in life, everything has a natural shape: tides, girls, history, oak leaves, and even planetary atmospheres. Sometimes we’re surprised and elated to see them clearly. Observers working on NASA’s Cassini mission to Saturn and Titan had exactly that reaction when the found a polygon over Saturn’s north pole.

Contrary to NASA’s article, however, patterns like this aren’t unheard of on Earth. Indeed, a similar, somewhat stable, dynamic pattern in atmospheric flow can be observed around the 500 millibar pressure-height for at least a few weeks most years.

Let’s take northern-hemisphere winter as an example. The overall motion of the atmosphere north of the tropics is west-to-east, that is, the Earth rotates counter-clockwise from the point of view of a satellite looking down over the north pole, and the atmosphere in this region rotates even faster than the ground. So, weather systems approach from the west and depart to the east. The paths taken by these weather systems are usually dictated by changes in the longwave pattern of the atmosphere, observable around the 500-millibar pressure-height. Shortwaves that generate weather move along the boundaries of a longwave pattern that spans the globe. These longwaves are called Rossby waves. You can get a feeling for how they work by looking at a plot of 500-mb heights like this.

If you look closely, you can see something not unlike a distorted pentagon forming in the image. The polygon of pressure heights in Earth’s atmosphere is much less stable and more distorted than that on Saturn, because Earth’s atmosphere is relatively thin, and the surface has wildly non-uniform thermal properties. So differences in cloud cover and how well the surface absorbs sunlight in neighboring regions keeps us from seeing nice, pretty shapes that last a long time.

On Earth, the number of nodes (i.e., number of sides to the “polygon”) in a pattern of atmospheric waves like this (called Rossby waves) changes regularly, and the rotation of the polygon about the pole depends on the number of nodes, k. In the above example, k=5. If k is large, waves propagate upstream slower than the atmosphere moves downstream, so they move west to east over the surface. If k is small, the individual waves are longer, and propagate upstream faster relative to the atmospheric motion. In that case, they can seem not to move relative to the surface, or even move east-to-west. There’s usually some possible k for which the nodal pattern in the atmosphere, as observed from the surface or from a geostationary satellite, seems stable.

Why go through all this? Well, first of all, according to current understanding, Rossby waves form in the atmosphere because of the changes in the Coriolis effect with latitude. As particles go north, the surface of the planet gets closer to the spin axis, so they have to speed up toward the east in order to conserve angular momentum, and that process eventually generates these wave patterns. Observations like this from Saturn, then, can tell us something about the horizontal motion of particles lower in its atmosphere. Secondly, these phenomena aren’t unique to planetary atmospheres. Fluid patterns eerily similar to those imaged on Saturn have been observed in the laboratory (thanks to user “hendric” over at Unmanned Spaceflight for pointing this out). Intriguingly, these laboratory observations cannot be explained by the Coriolis effect, because they are on far too small a scale for changes in latitude to matter. Whatever is happening on Saturn’s north pole is clearly related to what happens on Earth’s north pole, but it may also yield insight into forces and phenomena of fluid dynamics, not yet well understood, that can affect atmospheric behavior. It’s all very complicated and speculative and wicked awesome.

For the first time in many months, Sol presently features more than one sunspot. As the Sun (belatedly) pulls out of an extended lapse in sunspot activity, it becomes increasingly unlikely that we’re in for anything like the Maunder Minimum, a 17th century dip in sunspot numbers correlated (which proves nothing about causation!) with the Little Ice Age. It was always a matter of piling long-shot atop long-shot to suppose that such a change in solar behavior was a) under way, and b) likely to affect climate dramatically. However, with man-made climate change pointed the other way, a small reduction in solar irradiance would have been a welcome development.

It now looks like the solar cycle is back on track, but that doesn’t mean nothing interesting is happening. The spacecraft Ulysses–18 years old and on the verge of failure even as it transmits important data–reports solar wind levels are the lowest ever recorded. Meanwhile, I’ve heard an unconfirmed report that Earth’s magnetic field, slowly declining for years, has jumped significantly during the current solar minimum. As far as I know, nobody has even proposed an explanation for either of these developments.

We know very little about the Sun or the energy transfer dynamics of the Solar System. Thanks to the increasing political importance of climate-change research, that is finally slated to change. Ulysses was a great spacecraft, but it is ready to be replaced by a new generation of solar observation satellites. Among these is SORCE, the SOlar Radiation and Climate Experiment, launched in 2003. If you’re interested in modern satellite design and instrumentation, I strongly encourage you to check out that link. This is a well conceived and designed set of sensors, with a website far more detailed and informative than we are usually treated to. I eagerly await reliable information about long-term trends in total solar irradiance and spectroscopy.

UPDATE: One important measurement that cannot be made by satellites in low Earth orbit is solar wind velocity. We can’t reliably measure this from near Earth, because of interference from the Earth’s magnetic field. The logical successor of Ulysses in making observations that require some distance from Earth is SOHO, which has something of a storied history, located about 1.5 gigameters toward the Sun. SOHO has one instrument, SWAN, which should be able to estimate the mass flux of the solar wind. It operates by detecting the surface of intersection between the solar wind and electrically neutral particles from interstellar space. Given the availability of SWAN, I’m a little perplexed as to why NASA and others are referring to Ulysses’ solar wind observations rather than SOHO’s. Is something wrong, either technically or theoretically, with SWAN? If so, with the imminent death of Ulysses, we may lose the ability to monitor solar wind even as variations are being observed that may not repeat themselves for years or centuries. At least, off the top of my head, I don’t know of another current mission that can observe the solar wind.

No blog is complete without cute pictures of kittens and lemon sharks. So, here.

Fill in the blank: The universe is crazier than _____.

When answering, bear this and this in mind.

I think greenhouse warming is a serious problem to be addressed over the coming years. Nonetheless, some of the proclamations of environmentalists, and even scientists, make me want to throw things at a TV screen, monitor, or journal (though this last option lacks the satisfying smash of the others). Among the worst offenders in this category is the use of hellish surface conditions on Venus as a worst-case-scenario, allegedly demonstrating what can happen when greenhouse gasses get out of control. In honor of these alarmists, here are a few of the ways we could make Earth a little more like Venus:

• Add CO2 to the atmosphere (this is the one they mean). Maybe everyone could breath out at the same time?
• Move Earth 40,000,000-odd km toward the Sun. I think this could be done by getting everyone to stand on the light side of the world and throw rocks over the horizon. Later, the rocks would land, and everyone would go home, but the net effect would be to briefly increase the tidal force of the Sun upon the Earth (since the total mass would be spread out more along a vector from the Earth to the Sun), slowing the planet’s rotation and increasing the radius of its orbit, in accord with the conservation of angular momentum. The resulting cooler conditions would make everyone come in from the beach and work on science, so we could invent technology to move Earth 40,000,000-odd km toward the Sun.
• Destroy all life. (They think they mean this, too.)
• Increase the pressure of the atmosphere by about 9300%. Maybe we could all blow out really hard…

The latest edition to the blogroll is the excellent Planetary Society blog, which currently features in depth discussion of MER rover Opportunity’s ambitious 12-km trek to it’s next target of study, the crater Endeavour. I think there are two sound reasons to embark on such a mission. First, setting a long-term research goal (just getting to Endeavour might take a year) makes it harder for NASA administrators to kill funding for continued operations of the rovers, which, for reasons that perplex me, they otherwise might well do. Second, Endeavour is far away from territory previously covered by MER rovers, both geometrically and geologically. When using tiny robots to chart vast terrain, I think it’s best to keep moving, investigating as wide a variety of sites as possible. The rovers are partly designed to study scientific issues identified well in advance, like my work on dust devils, but the overriding goal of space exploration is to be in a position to observe the unexpected, the unimagined. Sending Opportunity on a potentially dangerous, but bold trip like this gives us an even better chance of stumbling upon something new. Kudos to Dr. Squyres and the MER team for this decision!