Business, Economics, Education, Mathematics, Media Criticism, Political Commentary, Science And Society, Technology and Society

Model Land

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Judith Curry, on a new paper concerning how to escape from it:

Naïvely, we might hope that by making incremental improvements to the “realism” of a model (more accurate representations, greater details of processes, finer spatial or temporal resolution, etc.) we would also see incremental improvement in the outputs. Regarding the realism of short-term trajectories, this may well be true. It is not expected to be true in terms of probability forecasts. The nonlinear compound effects of any given small tweak to the model structure are so great that calibration becomes a very computationally-intensive task and the marginal performance benefits of additional subroutines or processes may be zero or even negative. In plainer terms, adding detail to the model can make it less accurate, less useful. [Emphasis added]

Computer models can be useful in some circumstances, but they are not science.

Administrative, Business, Technology and Society

Computer Problems

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Yesterday, while installing a new router, my ethernet connection quit working. This morning, when I plugged the cable back in to troubleshoot, the computer died, and won’t reboot. This is a recent new motherboard. Not even sure how to start troubleshooting.

[Update a few minutes later]

I unplugged the cord from the power supply, plugged it back in, and the machine came back to life. Still no eth0, though.

[Update late morning]

OK, this is making me nuts. I went out to Office Depot, who didn’t stock any PCI-E ethernet cards, but they had a USB wireless dongle for thirteen bucks. I bring it home, plug it into the back of the machine, and the machine dies again. And this time, I don’t seem able to resurrect it.

An exact replacement for the mobo would be $150. But I’m not sure if I want another one.

[Update a while later]

OK, apparently when I was futzing around on the back panel, I was killing the switch on the power supply.

So I’ve plugged in the USB dongle, but the OS isn’t seeing it.

[Afternoon update]

OK, the OS is seeing the dongle, but it won’t connect to my wireless network. It attempts, then drops it.

In better news, I now seem to have a wired connection. The bad news is that I have no DNS. I can only ping by IP, not by domain name.

[Update a while later]

OK, I think I found the problem. Apparently my ExpressVPN account has expired, and it had written its nameserver into /etc/resolv.conf. I changed it to the router IP, and now it’s working (though I’m still getting a question mark on the network connection).

Biting Commentary about Infinity…and Beyond!