I hate scientific writing

Activities I consider preferable are:

• Getting knocked off a motorcycle at high speed
• Rolling a kayak with a broken tailbone
• Getting a hostile customs interrogation from drunk border guards

I don’t mind doing posters, and I love talking at conferences. And before I wrote my PhD thesis I actually enjoyed writing non-scientific stuff. And after a few years of post thesis shell shock, one reason I started this blog was to try and befriend words again. But after a month and a half of report writing, I’m having a relapse. So don’t be surprised if substantive blogging tails off. I’ve moved past the procrastination stage to the wimper under the desk stage. I don’t even have the motivation to ink a cartoon, which would let me post with no words at all. Goodnight people.

Fantasy GIS

When I was a kid, I played a fair bit of Dungeons & Dragons. Rummaging through old files this winter, I recently found a folder full of maps from a campaign I ran as DM from 8th grade through the early part of college. As they were a bit ratty looking, I decided to scan some of them, just for posterity. And that got me thinking.

One of the largest learning curves in my new job is learning GIS software. GIS, or geographical information systems, are computer programs that replace the laborious and repetitive math of map drawing with arcane buttons and incomprehensible menu selections which allow the computer to do the math for you. As I’m old enough to have learned geology in the paper and pencil era, I’m on a bit of a learning curve with plotting everything up. So I figured I’d register the adventure maps just for kicks.

A bit of sober reflection altered my plans, however. For one thing, I didn’t want all that junk on my work machine, and for another, using a format for a (very expensive) program I didn’t own seemed sort of silly. As Brian and Ron have been pointing out over the past few years, Google Earth is basically a poor man’s GIS. So I decided to use that instead.

Just like Google Earth, this ‘Google D&D’ is fully zoomable through the continental scale...

The regional scale...

And the local scale. The continuity between maps is better in some instances than others. The regional to local transition, which was done at high latitude and involved maps drawn several years before I learned trigonometry, is probably the dodgiest. But it is that scale at which the various tags and hypertext attributes start to become useful, as is shown here.

And at the dungeon level, layer control is great. Here I’ve color coded the dungeon layers so that their overlap is clear. The black ruined castle is the surface layer, while the underground layers are red, blue, and green.

And finally, we can turn off the clutter and zoom all the way down to look at the individual rooms in the adventure.

I don’t know if I would go so far as to try DMing paperless- there is a lot to be said for scribbling on maps and ticking things off. But it would be a great tool for generating things like player maps, as you can hide the DM only information just by deselecting the layer it is in. And if someone spills coke on the tactical map you can just print out another one and move the figurines.

And as a geologist, this has got me thinking. I’d love to plug the continental parameters into a coupled ocean-atmosphere GCM to see if I put the forests and deserts in the correct places. And I should probably check the orbital stability of the three moons*, as well.

I don’t know how useful this sort of thing would be for normal, well-adjusted RPG moderators. But I would have loved it 20 years ago. And I suspect it would be useful for anyone else who was socially awkward enough that they couldn’t say how a drunk goblin would react without knowing the orbital parameters, geologic setting, historical background, religious persuasion, and gardening habits of every sentient denizen of the craton.

* Unfortunately, in my ignorant youth I put the farthest moon beyond the planet’s Hill Sphere. I should really be more careful with my satellites.

Gender inequity in the Olympics

Well, the games are finally over, so all you Americans get go ahead and forget the metric system for the next 3.95 years. But now that the results are in, I thought I’d play with the numbers a bit.

The official website breaks the medal tally down into men’s and women’s events. Looking at the statistics, I noticed that a few countries were much more successful with one gender than another. There aren’t any sensible biological or geographic reasons for why this might be the case, so I decided to graph up the results just to see who fell where. Weighting the medals so that gold=3 bronze and silver=2 bronze, I calculated the fraction won by men.

I call this number the chauvinism index, as it seems to reflect the extent to which female athletes are not brought up to the same standard as their male counterparts. So a country with male medalists and no female medalists would have a chauvinism index of 1, while one with only female medalists would have a chauvinism index of zero. One minus the chauvinism index would of course be the emasculation index, and a perfect balanced nation would score 0.5 on both scales.

The Chauvinism index for all countries with ten or more total medals is shown below:


As you can see, the French are the biggest chauvinists, while the Dutch are most pussy-whipped. As if we didn’t know that already. Note that we expect the average to be greater than 0.5, since there are more men’s events than women’s events. Extracting trends or cultural significance is left as an exercise for the reader.

The nominal daddy

I usually associate the word nominal with spacecraft and other incredibly complex systems. But I reckon it’s great for parenting as well. If I told Mrs. Lemming that LLLL and I had a great time while she was away, then she’d feel unappreciated. Conversely, if I said it was horrible, she’d feel guilty. But nominal is just like the little bear’s porridge; by definition it requires that all parameters are operating within their correct range.
Eating? Nominal.
Sleeping? Nominal.
Play? Nominal.
Figuring out how to drink bathwater out of the floaty toys? Nominal.
Those special individual moments between father and child which we cherish forever? Nominal.
I’m going to bed soon, but I hope you all have a nominal Friday.

Daddy Time

Mrs. Lemming is off on a business trip, for her first 48 hour separation from LLLL. So it's primary parent time for this old lemming. So far, so good, with 3 hours down and 45 to go. The interesting bit will start tomorrow morning, though, probably sometime between 5:30 and 6:30. In the mean time, don't expect a whole lot of updates to this blog.

Mars- Dwarf planet until death?

Last week, I showed how the back of the envelope planethood calculations on Hal Levinson’s website can be solved for time to determine when a dwarf planet reaches planethood.

I then mentioned how planetary migration can move planets into uncleared orbits, or scatter stuff into an orbit that had been previously cleared.

I will now combine these ideas with the geologic history of Mars to show that the red planet may have only achieved planethood after its magnetic dynamo shut down, its oceans dissipated, and the volcanic activity subsided to a few isolated vents.

Here’s the Wikipedia version of Mars geology (corrections from anyone who knows better are welcome):

There are two ways to divide up the geological history of Mars. Crater counting gives us three ages- the Noachian (heavily cratered southern highlands), the Hesperian (less cratered northern plains), and the Amazonian (recent features such as some of the newer volcanoes).

Alternatively, mineralogical mapping shows that the Noachian can be divided into the Phyllocian- dominated by clays and water-bearing minerals, and the Theiikian, dominated by sulphate salts. The younger areas of Mars are classified as Siderikan- iron oxide dominated- in this classification system. I have no idea how they assign numbers to the relative ages, but both systems are shown below.


So how do these timescales compare with the time needed by Mars to clear its orbit?

As I mentioned last week, the time needed to scatter objects out of the orbital neighborhood is dependent on the angle of inclination between those objects and the planet-to-be, in this case Mars. So, we will plug in the orbital inclination for 3 of the 4 original objects in the asteroid belt, and see what happens.

Vesta has an orbital inclination of 7.1 degrees. Plugging this into the formula gives a clearance time of 358 myr. On this time scale, Mars clears its orbit, enjoys a few hundred million years as a planet, then has to do it all again when the Late Heavy Bombardment scatters asteroidal riff-raff back into the newly cleaned neighborhood. Mars is a planet for about one quarter of the Noachian, and is a Dwarf planet the rest of the time.


If we increase the orbital inclination of the debris field to that of Ceres- 10 degrees- then Mars no longer has time to clear the neighborhood before the LHB messes it up again. The clearance time is almost a billion years, so Mars is a dwarf planet until the mid-Hesperian, or about a third of its life.


Finally, if we further increase the inclination to 13 degrees- similar to 3 Juno- then the clearance time blows out to 1.8 gyr, as shown below. This results in Mars being a dwarf planet for half of its life, and only acquiring planetary status towards the end of the Hesperian, when most planetary processes have ceased functioning. This would make Mars a posthumous planet.


The red planet has been the centre of the public’s interest in planets since the days of Edgar Rice Burroughs and H. G. Wells. It currently has more interplanetary missions operating on and around it than do the rest of the planets combined. Most of this scientific interest revolves around past habitability, specifically during the earliest, wettest eras. If Mars is demoted to dwarf planet during this period of time- as the above calculations suggest the current planet definition requires- then how useful is this definition?

The current Eriphobic planet definition didn’t just demote Pluto. It also forced Mars to die before it could join the planet club.

Space carnival 67

Is up at Next Generation.

Planetary mid life crisis

Last post, I mentioned how the current IAU definition of a planet causes many of the classical planets to only attain planethood late in the solar system’s history. Saying that a planet has to clear its neighborhood implies that a planet has only one neighborhood. Interpreting this law in the context of planetary migration is tricky.

For example, an abbreviated timescale is shown below.



The red area to the left is the 30-50 million year time that it took the terrestrial planets to form. As is shown, moon rocks can be found that are only slightly younger than this. The orange band is the age of the Late Heavy bombardment, which created the large lunar impact basins. This is hypothesized to have been caused by Neptune and Uranus changing their orbits. Neptune, in particular, would have ended up in a new neighborhood, and had to clear it, scattering stuff all over the solar system.

Under the IAU definition, it is unclear if Neptune ceased to be a planet during that time, and if so, when it regained planethood. Similarly, if the objects were scattered into the path of other planets (which seems to be the case), did they also lose planetary status for this period?

Many exoplanets show even more extreme examples of planetary migration. So if we want a consistent definition for all systems, it is unclear how this will apply.

Note that in the time scale above, the LHB happens long after the planets are formed. Planetary processes were well and truly underway on all terrestrial planets at the time of this bombardment, and to suddenly toss in a period of non-planetness makes no sense whatsoever.