Sunday, June 28, 2009

The Quite Possibly Never-Ending War On Ants...

Almost a year ago, in my ant-conquering arrogance, I made a crazy statement about almost being ready to declare victory. I hereby officially retract that grotesquely optimistic statement.

However...that is not to say that the RTV strategy is without value. Quite the contrary. Before about a year ago, our routine reaction to discovering ants was to break out the weapons of mass ant destruction (chemical weapons, that is) and madly spray them over anything that crawled within a 150 foot (or so) radius of our home. Most commonly this approach would immediately reduce the ant numbers, but not drive them completely away.

The new strategy, now being employed for about a year, is much different. No weapons of mass ant destruction are involved – just some ordinary RTV (self-curing silicone rubber, commonly sold in caulking tubes). I simply follow the ants (generally in the kitchen) back to whatever hole they're entering from, and caulk it. After that, for somewhere between 10 minutes and 2 weeks, we are ant-free – completely, totally, and utterly ant-free. And this despite the lack of chemical warfare on the ant nests outside.

This morning was quite typical. We noticed a few ants running around on our kitchen island – these were “explorers”, looking for some tasty treat. I gave them one – a dish of sugar water. Three hours later, there was a well-defined ant trail between the dish of sugar water and their entry point, which was a crack between the baseboard and the wall. I caulked the crack and cleaned up all the ants I could see with a paper towel. I knew from experience what would happen next – you can see it in the photo above.

First, the RTV caulking acts like some kind of repulsion shield to the ants – they won't touch it. That's the blue-circled area in the photo. Second, they'd start congregating in total confusion nearby the old entry point. I think what's going on there is that more and more ants show up, each laying down a pheremone trail, and that just attracts other ants all the more. About an hour after I caulked the crack, I took the photo above. In another couple hours, there will be another congregation – the more far-ranging explorers trying to get back to the nest.

So now we're ant-free once more. But I have no idea how long it will be until they pop up somewhere else...

Jamulian Morning...

Yesterday morning I went “down the hill” a bit later than usual, as I was called into work unexpectedly. As I crested the hill on Skyline Truck Trail, just before coming down into Jamul, this scene greeted me. It's typical for this time of year – clear and sunny east of Jamul town, but foggy as you get closer to the town.

These two photos aren't the best – I took them with my cell phone. But you'll get the idea...

The photo at left is looking to the south from my vantage point. The mountain in the distance on the left is Otay Mountain; to the right is San Miguel. The small peak just below Otay is Jamul Butte.

The photo above right is toward the west. San Miguel is in the center, with a couple of smaller, much closer hilltops jutting out of the mist like little islands...

Ulysses, RIP...

One of our most productive robotic explorers is nearly at the end of its road. Ulysses was launched (via space shuttle) in 1990, and reached it's orbit around the sun in 1992. Ever since then – nearly 18 years – it's been doing great science. Its measurements of the sun, and most especially the sun's magnetic field, have contributed enormously to humanity's knowledge about the solar system.

Ulysses is yet another JPL/ESA project that far exceeded its original expectations, sending home years more science data than was originally planned. Last year the Ulysses team was almost ready to end the mission due to some failures – but some very clever engineering eked out yet another year of successful operation.

But now a combination of circumstances has brought a decision to shut down Ulysses. The biggest factor appears to be this: it's low-powered radio transmitter and great distance means that Ulysses can only be heard on JPL's 70 meter antenna network. This network has great demands upon it, so its time is valuable. Ulysses has been getting by with “spare time” use of the antenna network, meaning that it took whatever dregs other missions made available through last-minute scheduling changes, etc. Ulysses is getting further and further from earth, so its signal is weaker and weaker – which means a lower and lower bitrate on the data even when it can get antenna time. Simultaneously the demands on the 70 meter antenna network are getting even more intense. So the mission controllers decided that Ulysses had finally reached the point where the science value of its data was no longer worth the cost, both in terms of antenna time and in terms of maintaining the mission team.

So on June 30 (this coming Tuesday), the mission controllers will send a signal to Ulysses to tell it to turn itself off. It will remain permanently in orbit around the sun, a monument to mankind's achievments that will remain no matter what we manage to do to ourselves...


More information here, here, and here.
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