Particles

Particles are a type of Entity in Minecraft; they are graphical effects. The particles always seem to face the player and will usually disappear after a short period of time

You can reduce the amount of particles visible in the Options menu.

Types of Particles
In Minecraft's code one can find a variety of particles. To help modders or curious players, the types of particles and their real names in the game's code are displayed below. Particles collide with solid blocks and are slowed down by cobwebs, but are unaffected by other entities. Each particle texture is 8x8 pixels.

Particle-detector
A Particle detector activates a redstone output, whenever a particle drops near from the detector. Every particle (block-breaking-particles,snowballs,splash-potions,eggs,etc..) is detectable, as shown here:

(Particle-detector)

Experimentation reveals that as of Minecraft 1.2.5, a detector rail will trigger when a particle, mob, or any other entity except an arrow touches it if there is a minecart slightly overlapping it, which is most easily achieved if the minecart is on a downward slope and pushing into a fence post or fence gate above the powered rail, as shown in the video. The pressure plate seems to be irrelevant.



The detector rail will stay on until the minecart is no longer touching it, so a fence gate is preferable to a fence post, as the detector rail instantly powers and opens the gate, releasing the minecart. However, this requires some sort of minecart return mechanism, also as shown in the video. The video uses a closed loop, which can break if a player or mob pushes the minecart the wrong way, as the detector rail will open the fence gate and allow the minecart to continue moving. A simpler solution is to use a linear track, with powered rails reversing the direction of the minecart at both ends.

Note that the powered rail on the bottom right does not need to be powered with a redstone torch, as the detector rail powers it when the mechanism is triggered.

Trivia

 * Most particle colors can be changed using texture packs, however the color of smoke particles used in redstone, portals, and Endermen can't be changed without mods or third-party tools. (They will always be red or purple)


 * Mobs spawned using a Monster Spawner emit smoke particles when spawning.
 * The particles generated while sprinting are parts of textures extracted directly from the terrain.png file in the minecraft.jar folder. This is shown by the fact that grey particles are emitted when sprinting on leaves.

Gallery
Partikel