Tuesday, August 20, 2013

Instant Chat Application

Here's a version of the instant chat system I mentioned in my previous post. It updates in real-time, so unlike most forums, you don't have to reload the page to see new comments.

You can include HTML in the comments, but I disabled the <script> tags because users misused them. I also added a <console> tag and an <incode> tag. To post a comment, either click the button or press the Alt key on your keyboard.

There may or may not be other people on the chat app. If you want to chat with someone, email the link to that person.

If you do not see the app, please click HERE.



Instant Chat Application
Instant Chat System
INITIALIZING...
Name:

Wednesday, August 7, 2013

Mesocyclone


The sky was dark. Occasional raindrops pattered outside. Thunder rumbled. A computer geek sat in the glow of a computer, typing and staring at the screen as if in a trance. He happened to be working on an instant chat application, using HTML, CSS and JavaScript. When he was complete, he would host one version of the app on his Computer Science blog. He later hosted another version HERE.

Suddenly, the wind outside picked up all at once. As it howled, the windows cracked and popped. At one corner of the house came a spooky moaning sound. Only then did the geek come out of his trance; he stopped typing and turned towards the window.

That geek was me. The reason I ceased to type was because I knew that the pickup of wind was unusual, and that it can be a sign of a nearby tornado. I scanned the fields, trying to guess approximately how strong the wind was. The wind had picked up dirt and was blowing it through the fields, so I knew from experience that the wind was particularly strong. I got out of my chair and looked up at the sky through the windows, checking whether a tornado was forming. Ever since I was very young, I was fascinated with tornadoes, and was always on the lookout, hoping to see one. I sometimes dream about tornadoes. Unfortunately, we live in a place where tornadoes are rare, so I've only seen a single tornado my whole life.

I noticed clouds turning in the sky - a mesocyclone. A mesocyclone is a vortex of air within a convective storm - that is, rising air that spins. I called the rest of my family to come look at the turning clouds. I ran and got my camera, and started filming. I really hoped some kind of tornado would form; even a small, weak one would have satisfied me. I watched the clouds as a funnel started to form. Then it dissipated; a tornado never formed.

I had been hoping for a tornado, but what I saw was the next best. I had read a lot about mesocyclones, cumulonimbus clouds, and thunderstorms, and it was very interesting to see it in real life. I could even see the opening for the rear flank downdraft.

I later took the videos I got and removed parts of them. Here's the result:


Saturday, August 3, 2013

Pileus Clouds

A cumulus cloud with pileus. This pileus is a small one.
There are multiple pilei on the cloud in this photo.
See if you can find them.
Pileus, pronounced pie-lee-us, is a small, smooth, silky-looking lenticular (lens-shaped) cloud that can appear above parts of either a cumulus or cumulonimbus cloud. (If you don't know what a cumulus cloud is, click HERE. Cumulonimbus clouds are basically very large cumulus clouds.) A cloud attached to pileus is said to be "with pileus" or to "have pileus".

Clouds with pilei can develop into very large
cumulonimbus clouds.
Pilei form when a strong updraft at a lower altitude acts upon air at a higher altitude, and causes it to cool below its dew point. The result is that as the air cools, the water vapor in it condenses and forms a cloud. Because of the conditions required for it to form, a pileus cloud is usually a sign of severe weather; the cloud that it forms above is likely to develop into a cumulonimbus if it hasn't already.

Early this afternoon, it was bright and sunny, but there were a couple of cumulus clouds with pileus, so I immediately predicted a thunderstorm. Sure enough, only a couple hours after that, it started raining harder than it has in a long time, and I could smell ozone from the lightning that kept flashing outside.

It isn't raining any more, but I can see a huge cumulonimbus far in the distance, and dark clouds overhead.