Friday, May 10, 2019

How Not to Get Lost in Caves and Structures in Minecraft

Caving is an essential activity in Minecraft but it can be quite a challenge at times. Hostile mobs spawn in the darkness, mob spawners can pose a problem, and the twisty nature of caves and structures can be quite disorientating. In complex caves or structures that have multiple paths and levels, it is quite easy to lose your way.

One long-held technique is to create a torch path on the left or right side of the cave wall so that you can follow the torches back out of the cave. This works fine for relatively simple caves, but if the cave has multiple loops and levels, the torches begin to run together and cease to define a simple path out of the structure. I found the torch path to be inadequate so I developed my own method that is both simple and robust.

The only items you need to implement my pathing technique is a supply of cobblestone and a good supply of torches. I use cobblestone because it is cheap and does not naturally occur in caves or structures aside from dungeons, so stands out nicely from the native stone.

Figure 1: Basic Technique

As you can see from Figure 1, the basic technique is to place a cobble block at an intersection, with the torch facing the path that leads out of the cave or structure. As you place the blocks and torch at each intersection, all the torches will be facing the direction you need to go to get out of the cave. Of course, you would light up the cave as you explore like you would normally, the path blocks would only be needed at cave or structure intersections.

Figure 2: An Instance of Pathing in a Maze-like Structure

Figure 2 illustrates an instance where wall torches can become a problem if special care isn't taken to ensure a clear path. This part of the stronghold has numerous rooms that all connect to each other in a grid pattern. It would be quite easy to get lost in this maze, but by simply using path blocks when you enter a room, you have an unambiguous path out of the maze. 

The other problem you encounter in caves and structures is changes in levels where a junction could lead left or right and up or down. It is quite difficult to torch this correctly, but by using two cobble blocks on top of each other and then placing the torch on the top or bottom block, you have a clear indication of which direction and which level to travel.

Figure 3: Path Blocks Indicating Downward Path

As you can see from Figure 3, the torch is placed on the bottom block. This indicates that the proper path is down. What is not shown in the picture is a stair leading up and a stair leading down. I came into this room from the stair leading down, so I place the blocks at the entrance of the room, and the torch on the bottom to show that the correct path is down.

Figure 4: Path Blocks Indicating Upward Path

Figure 4 shows the proper technique for a path that goes in an upward direction. The torch is placed on the top block to indicate you need to go up. 

That is all there is to the technique. It is quite simple and very cheap to implement, but I have found it to be extremely effective in creating a path through both simple and complex caves. Not only is this pathing technique useful for exiting a cave, but it also useful if you wish to travel back to the last position you had in the cave if you want to continue exploring. Next time you enter a cave, give this technique a try and see if it works for you.

Sunday, March 17, 2019

Why Time Travel (Probably) Isn't Possible

One of my favorite science fiction tropes is the time travel story. The idea of going back and forth in time fascinates me, and I have spent quite a bit of time thinking about the concept. In science fiction, there are many different ways authors have looked at the effects of time travel. Can I change the past or is it locked in place, unchangeable? If I travel in time, do I create a completely different chain of events creating a new timeline that different from the one I started in? Many different ways to look at the idea.

The idea of time travel, and one the biggest problems with the concept implies the possibility of the paradox; the chance that something can occur that shouldn't be normally possible. The classic case is the grandfather paradox; suppose I travel back in time and kill my grandfather, thereby wiping out any possibility of me having been born? How could I then go back and kill my grandfather? It is the chance of creating a paradox that many scientists do not believe that time travel is possible since this type of paradox simply could not occur in the real world. However, this really doesn't tell us why time travel isn't possible, it just speaks to the wide dislike of the paradox in scientific circles. The current scientific models we have do not exclude the possibility of time travel. It doesn't violate any laws other than then maybe the hypothetical law of conservation of information.

The grandfather paradox is quite interesting to me. If time travel were indeed possible, then the grandfather paradox has to be a possibility. Yet, it does not make any sense that it actually could be possible. I felt that there had to be a reason why it isn't possible, even if time travel were a reality. After thinking about it for some time, I think I have discovered why not only is the grandfather paradox not possible, but time travel itself is not possible. The very act of time creates a paradox of its own, one that I think forbids the possibility of time travel.

The main assumption here is that somehow time travel is possible. It doesn't matter how, but we have the ability to travel in time from point A to point B. Before I get into my hypothesis however, I first need to define what I mean by traveling in time from point A to point B. What I am referring here to here are destination points, not only in time but in space. I exist now in time, and I also exist now in space. That is, I have a physical location that I can associate with this moment in time. Einstein saw this relationship between time and space and called the concept space-time. As we move in space we are also moving in time. If we move through time, then we are also moving through space. The two have to go together.

This is important because point A in time is also point A in space. Point B in time is also point B in space. These are very real destinations that have a real position in space-time. Imagine that Point A is my home and Point B is the grocery store. To get to the grocery store I travel through space and this traveling takes a certain amount of time. I have traveled in both space and time. If I wanted to go back in time to the moment I left for the grocery store, I would then be traveling in space, from the grocery store to my home.

Now, there is one key aspect of this model that is vital: both your house and the grocery store have to exist at the same time. That is they have to exist simultaneously. Yes, thank you Captain Obvious. However obvious this is for the present, this idea of simultaneous existence of destinations has to be true for time travel as well. If I want to travel back to 1974 and tell myself that the girl I was about to start dating was a big mistake, 1974 has to exist at the same moment that 2019 exists in order for me to travel back to that point in time. Again, we are assuming that time travel is possible here, so 1974 has to exist simultaneous to 2019. These are real destinations, no different than my house and grocery store.

Herein lies the problem. I can travel to any point in time, so every point in time is simultaneous to every other point in time. That is, all of space-time has to exist at the same time. A lot of time there, so let's step back a moment. Suppose we exist outside of time so that we can see the full length of space-time from the big bang to the final moment of heat death. There spread before us is the whole history of space-time like a mural on the wall. We can look at any point in space-time we want. Because we are outside of time, we don't see the flow of time, but a static unchanging image of space-time. Because the image is static, that is unchanging, it is eternal. It is like a picture, each point frozen and unchanging, yet accessible. If time travel were possible, then this is what the universe must be like, a static, unchanging, eternal universe. Every point in time existing at the same time as every other point in time means that the universe has always existed, because if at some point it didn't, then not every point in time could be simultaneous. Because we are assuming time travel is possible, the only way this can occur is if the universe is eternal and unchanging.

This is the paradox: if the universe is eternal, how did it start? How did we get the timeline? The fact that we can travel in time implies that time has changed from moment to moment, but if it had in fact changed than we wouldn't be able to travel in time at all. It is this paradox that I feel forbids time travel. The universe had a beginning, and anything that has a beginning cannot be eternal, because, at some point in time, it did not exist. Something that is truly eternal has always existed. Now the universe will exist eternally into the future (maybe), but since it had a beginning it is not eternal. Since it isn't eternal, that is the universe has changed over time to create the timeline we see in the universe today, 1974 cannot exist simultaneously with 2019, therefore time travel isn't possible.

There is one apparent loophole however, that I want to address; maybe we can only travel back in time since the future doesn't yet exist? The idea here is that once we pass 1974, it becomes frozen, a point that we can now visit since it has been created in time. The problem here is that my future is also my past. My 2019 self can return to my 1974 self, yet as far as my 1974 self is concerned, my 2019 self does yet exist. Traveling to the past implies that there is a future that can also travel to the past, which means that the future has to exist simultaneous to the past in order for that travel to be possible. Travel any direction in time implies travel in both directions of time. The loophole doesn't really exist. This same reasoning is also valid for the “create a new timeline” scenario as well. Any traveling in time, regardless of the outcome, creates the same paradox.

These are my thoughts on time travel, however, I put “Probably” in the title, because I may be missing some vital point here. This all makes sense to me, but again there isn't really anything forbidding time travel so it is possible I am missing a point that does away with the paradox that I think time travel creates. 

I still love to read and write time travel stories however because I find the possibilities too interesting to ignore. It is still my favorite.