Category Archives: Mathematics

More Virtualbox Problems

So, I’m running Fedora with Gnome. When I fire up Windows 10 in Virtualbox, the VB menu tabs appear at the bottom of the virtual machine, covering up the tray. Of I attempt to minimize it, it leaves the Windows window. When I reclick on it, the tabs are still there. If I try to close it, it freezes the host. I can switch workspaces, and windows, but I can’t do anything within them; clicking on links, or new tabs within a browser instance, does nothing. The cursor remains an arrow regardless of its location. The only way to fix it (that I’ve found so far) is to reboot, which is a PETA, because a lot of stuff has to be autoloaded each time.

Any ideas for troubleshooting?

[Saturday-afternoon update]

OK, I have discovered that I can unfreeze the host without having to reboot, by killing the VM process. So that will help. But it’s still not switching properly between full-screen and scaled modes. And I still have to modprobe the driver every time I reboot, or the machine won’t start.

Merging Lanes

You’re probably shifting out of your lane too soon.

Driving back from Yosemite on Thursday, Caltrans had shut down the right three (out of four) lanes on I-5 in Castaic. We lost one lane at a time, and the first merge was the slowest. Each next one sped things up, until we were all in a single lane, and moving at a reasonable speed. Part of the problem was that much of the traffic in the right lane was trucks (we were already in the left lane when the backup started). It added about twenty minutes to the trip time.

VirtualBox Problem

[Wednesday update]

For those interested, ‘modprobe vboxdrv’ did the trick.


I was running Windows 10 in it on the Fedora host, and it crashed. I updated the entire system and rebooted. When I tried to restart the virtual machine, I got this message:

The VirtualBox Linux kernel driver is either not loaded or not set up correctly. Please try setting it up again by executing ‘/sbin/vboxconfig’as root.

If your system has EFI Secure Boot enabled you may also need to sign the kernel modules (vboxdrv, vboxnetflt, vboxnetadp, vboxpci) before you can load them. Please see your Linux system’s documentation for more information.

where: suplibOsInit what: 3 VERR_VM_DRIVER_NOT_INSTALLED (-1908) – The support driver is not installed. On linux, open returned ENOENT.

When I run the config, I get this:

When I look in the log, I get this:

Continue reading VirtualBox Problem

Industrial Revolution

Why didn’t the Romans have one?

Before I read it, the first thing I thought was this: “How are engineers to do experiments and calculations without any concept of the experimental method, and without anything close to the mathematical tools that are available today to any fifth-grader?”

As he notes, they didn’t have Arabic numerals, they didn’t have zero, they didn’t have negative numbers, or complex numbers. They had no higher math, and no way to get to it with their numbering system. One of the foundations of the industrial revolution was the invention of calculus, and understanding of physics, including thermodynamics. That was all happening in the seventeenth and eighteenth centuries. The other thing that was happening was the invention of capitalism in the coffee houses of London and Amsterdam (which wouldn’t have happened had coffee not become a thing in the wake of opening the New World). It’s not clear how, even had Rome not fallen, how they would have ever had those foundations.

[Update a while later]

Link is fixed now, sorry.

Hot And Bothered About Heat Waves

No, we can’t conclude anything about climate change from them.

“In fact the most recent (2021) report of the Intergovernmental Panel on Climate Change (IPCC) does not support the common claims about drought, floods, hurricanes and other severe weather events. Not only does the last IPCC report find no clear trends, it offers “low confidence” in predictions of future trends.”