You may have had to work with a compressed folder before. Likely, you’ll remember its icon (a folder with a zipper). Maybe you remember that the file you downloaded ended with the .zip file extension. Every time you download a compressed file folder, you have to go through the annoying step of clicking “extract” to get your files. What’s the point? Can’t the files you want just be downloaded as they are?

The answer to that question is yes, but not really. This is because while websites have the ability to host and send uncompressed “original” files/folders, these are much larger in size than the compressed version. In order to increase efficiency, downloads and uploads of large/multiple files are done using file compression.

But how does this work? How is it possible that a file can just become smaller?

File compression works by reducing redundancy. This is best explained with an analogy:

Let’s suppose you wanted to write a comprehensive list of instructions on how to assemble an IKEA dining table and chair set. When writing the instructions to install the legs onto the chairs, you probably would not write the instructions one time for each leg of the chair. Rather, you’d write it once, and then indicate to repeat it three more times, once for each leg. Similarly, when writing instructions for assembly of the chairs, you would only write one, and then indicate to repeat the process once again for each remaining chair.

via GIPHY

This is the essence of a compressed file. Repeated consecutive data is condensed into a single copy of that data with an indication of how many times that file is repeated. Other patterns in data can also be picked up by compression software and condensed into more compact data.

The above form of compression is called “lossless” compression because when decompressed, the output file is exactly the same as the original. However, for certain applications, not all data needs to be perfectly retained. In the world of audio and video downloads, “lossy” compression leads to even smaller files that, when presented to most consumers, are practically indiscernible from the original media. In this form of compression, not only is redundant data eliminated, but data that encodes details that the consumer will likely not notice is also eliminated.

Exactly what data encodes “details that consumer will likely not notice” is determined by the type of file compression used. For example, in audio files like mp3 files, one way in which compression is achieved is by ignoring very quiet sounds that play at the same time as louder sounds. Another way compression is achieved is by eliminating very high and very low frequency sounds that humans usually do not perceive.

With a lossy audio compression method like mp3, a song can be compressed to a file 11 times smaller than the original. In contrast, a lossless audio compression method like FLAC (which, again, only eliminates redundant data) can only compress a song to about half its original size.

From the outside, file compression seems like magic. At the detailed level, file compression is highly technical and difficult to understand. However, on the surface, file compression is comprehensible: it just gets rid of things you don’t really need.

PC cooling isn’t something you’d expect to be interesting at first glance. You probably are thinking of your laptop’s annoying fan that spins up occasionally, or maybe you think about your desktop at home and it’s dusty fans. However, in the world of hobbyists, anything can be crazy if you throw enough money at it.

People throw money at PC cooling usually for one of three reasons:

1. They are a PC speed addict
2. They are looking to break PC speed world records
3. They have a lot of money to throw and nowhere else to throw it

Often, these hobbyists install a liquid cooling system (not unlike that in a car) with a pump, a radiator, and pipes leading to and from the hot components. These tend to look quite nice and perform well. However, things get more interesting the deeper down the rabbit hole you go.

If someone wanted a nice conversation starter as a PC, they could end up with something like this:

This is a PC submerged in a special liquid formulated by 3M that is electrically insulating and thermally conductive. It also has a very low boiling point (34°C) such that it simply boils off at the surface of hot components and then condenses at the surface of the fish tank PC and releases the heat to the air.

This is not the most practical way to cool a PC. (This is definitely not the most practical way to start a conversation.) Replacing a component would be messy work, and the PC would probably have to be drained and refilled every time it is transported. Oh, and 3M’s special liquid is $285 per gallon.

However, you cannot argue that this is not pretty interesting. Maybe it could get more interesting, though; we need to go deeper.

This is a computer motherboard. Yes, that is frost. For those few looking to break world records, this is how they go about it. First, they tell the computer to draw tons of power and ramp up its internal speed. Then, they pour liquid Nitrogen or liquid Helium into the “pots” on the (not for long) hot components of the PC.

This may seem like overkill. After all, liquid Nitrogen exists at -196°C and liquid helium exists at -270°C (which is 3 degrees above absolute zero!!!). However, people looking to break world records are looking for every last drop of overkill they can get.

At this point, it may seem a bit strange that these things even exist. What’s the point? Can’t I just keep on using my good old air-cooled HP laptop? Absolutely. Air-cooling still works and is still cheap.

Honestly, I can’t come up with a good reason for these methods to exist. They’re a waste of money for most people and don’t give much in return. However, hobbyists will be hobbyists, and I’m glad. I’m glad because they’re out there creating the next crazy technology and I get to sit here, on my regular air-cooled PC, and watch the incredible technology develop right in front of me.

In a previous post, I explained how a standard consumer 3D printer works. However, why would anyone use a 3D printer? In this post, I will go over the benefits and downsides of 3D printing parts instead of manufacturing them with more conventional methods.

Before speaking on the use cases in which 3D printing is viable, I first want to cover 3D printing’s major downside: it’s takes a really long time to print large quantities of objects. On the other hand, traditional methods such as vacuum-forming and injection-molding can produce massive quantities quickly and cheaply once properly set up.

However, it is this setup that is what is holding traditional manufacturing methods back. These methods require that you take the time to make specialized molds and other specific pieces. This time is tough to justify when you only need to manufacture a small batch of maybe 50, or even 5 parts. This leads me to the major upside of 3D printing: easy, immediate results. Once a design is decided on, a 3D printer can print out a copy of the design within a day, or even hours. Especially for people prototyping and constantly changing a design, having to create a new mold for a traditional plastic forming method would be dreadful. With 3D printers, each new design can be (almost) immediately obtained and tested.

Another downside to 3D printing is the limitation in choice of materials. Most 3D printers can only print in a few types of plastic (and sometimes pancake mix). A few industrial 3D printers can print with metals and ceramics. However, if you want a part made of wood or glass, 3D printing can’t make it yet.

On the other hand, 3D printing can create things with these few materials that other manufacturing methods simply cannot do. Take, for example, this faucet:

The water runs up through the inside of the spindly, hollow helices and converges at the top, running out the head of the faucet. Traditional manufacturing methods cannot produce complex geometries such as the hollow, spiraling, intersecting metal pipes seen here. This is something that is only possible through 3D printing.

3D printing is also known as additive manufacturing. This is in contrast to many subtractive manufacturing methods which carve out material from a large chunk to form the object, such as turning and milling. These subtractive manufacturing methods by nature waste material as they carve, making working with expensive materials difficult. However, with 3D printing, expensive materials can be preserved by only using as much material is needed to create the part. This is why additive manufacturing (3D printing) is becoming more popular in the aerospace industry; titanium airplane parts are expensive, and 3D printing enables companies to create large parts out of titanium without the traditional large amount of waste.

Because of the above reasons, 3D printing is becoming more and more popular in manufacturing and engineering. While it is slow and limited in materials, it can create things that other things simply can’t, and it can produce them immediately.