Minecraft streamer JL2579 is riding a minecart to the end of his Minecraft world, and you can watch it live. The trip will take over 17 days since the minecart travels at 20 meters per second, and his world is over 30,000,000 meters long. This means he will be traveling over twice the diameter of the Earth to reach the edge of his Minecraft world.
A couple of questions immediately pop into mind when seeing this stream. First off, isn’t  a Minecraft world theoretically infinite? Technically it can be, but the physical reality that we live in, along with changes from Mojang prevents it. As the world generates more and more of itself the world file size grows. In previous versions of Minecraft there was a point at which the file became so massive that it began causing issues with the world generation program. Minecraft players refer to this as the Far Lands.
More up to date versions simply have the file reach the limit of the hard drive on which it resides. This seems to be the case for JL2579’s world.  UPDATE: I was misinformed on this element of the game. At 30,000,000 blocks away from your spawn point, which is where JL2579 is heading, your character will no longer be able to proceed. Some versions have an invisible wall, while others simply create fake terrain that you cannot stand on. This was an update from Mojang to recent versions of Minecraft.
JL2579Â said he upgraded his hard drive specifically for this stream due to his world size reaching 286GB. Once the stream is finished JL2579 promises to upload the world file so that anyone can download it. With it being over 200GB that download could take almost as long as the journey itself.
The second question is, how did he construct a minecart track all the way to the edge already? The answer to this is that he didn’t. JL2579 has set up a perpetually repeating section of track using command blocks. As the world generates a new area, the command blocks set up the track and he is able to continue on his way. This means that even he has not seen the edge of this world yet, so we are all seeing it form together for the first time.
With a stream like this which stretches over multiple days, the main concern is what happens if the game or stream crashes. There have already been two recorded incidents, and JL2579 says that he will try to keep on top of it and make sure everything runs smoothly. He does have to sleep and eat at some point though, so there might be a few stretches of downtime on this long journey.
