I’ve had this problem for some time now and chose today to do some research. Luckily, I found a workaround pretty quickly.

I use the Mozilla based browser GNU IceCat which is functionally equivalent to Mozilla Firefox. When a page is requested, the browser displays a small spinning icon in the left corner of the tab. Loading a page involves three basic steps: converting the URL into an IP address, contacting the web server at the IP address, receiving the web page (and other resources). During the first two steps, the icon will be grey and spinning counter-clockwise. The status bar will show messages like “Looking up google.com” and “Waiting for google.com”. Typically, DNS queries (the first step) take on the order of 100 ms to complete. Therefore if you see the first message, you may have the same problem.

The symptom was that IceCat (Firefox) was taking about 3 to 5 seconds to make DNS queries every time I tried to navigate to a new address. The cause of the problem seems to be that my system is making IPv6 DNS queries first by default but these types of requests are being ignored by the DNS resolver which doesn’t support IPv6. My system sends a query and then waits a certain amount of time before giving up and trying an IPv4 query. That time waiting was the delay I was experiencing.

The ideal fix would be to change the way the DNS resolver responds to IPv6 DNS queries. That’s obviously out of my control. A system-wide fix involves setting up your own DNS resolver – a bit more work than I’m interested in. The easy fix was to address the issue for IceCat (Firefox) only which is good enough for me as web-browsing is my primary internet activity.

The fix is to change the value for the key “network.dns.disableIPv6” from “false” to “true” in IceCat’s (Firefox’s) “about:config” page.

For more information, the issue has been discussed extensively here:

https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/417757

In order to use a light bulb to illuminate the inside of a vacuum chamber, I needed to release the gas contained within the bulb else it would likely have exploded the bulb when the external pressure was reduced. However, I wanted to keep the glass intact in order to protect the fragile filament from my clumsy hands and to provide that soft white glow.

I first tried scoring and breaking only a small piece of the bulb, but that always resulted in an uncontrolled cracking/shattering of the entire bulb. The best suggestion I found on the internet involved using a CO2 laser to make the hole. That would probably work, but I’ll save building a CO2 laser from scratch for another day. Other suggestions typically involved drilling under running water at very low speeds with a very sharp drill bit. Since both patience and drills were in short supply, I tried another method.

I found that by using a metal file at a tangent to the glass, one can very slowly thin the glass in a relatively small area. In my experience, eventually the thinned glass breaks away leaving a small hole. The hole isn’t round and doesn’t form in an absolutely controllable way. Perhaps it may be possible to “punch” a smaller hole after thinning the glass but before it breaks.