When the first Star Trek was released to the public, people were shown a futuristic society where humans were able to communicate with small devices, teleport across vast distances, and fight with futuristic weaponry. While we have accomplished the first and have a long way to go on the second, it appears we are already well on the way to the third.
1. Energy Weapons and Lightning Guns
Laser technology is already well on its way to being weaponized, having been installed on the USS Ponce, and may be deployed as soon as 2014. The laser weapon offers a number of potential military applications, including non-lethal (dazzling a pilot), and defensive (anti-missile).
Another potential application of lasers is to create lightning, or using a laser to guide bolts of electricity to targets. The Laser-Induced Plasma Channel, as it is called, could be an effective means of targeting enemy metallic objects. A sufficiently powerful laser pulse can form plasma by ripping electrons from the surrounding air, creating a highly conductive current for electricity. Aimed correctly, the plasma will fly close to enemy metallic objects, where the path of least resistance to the ground will divert the energy and create an explosion. The force generated even by a small pulse (two-trillionths of a second) would be significant, sufficient to destroy a target without causing damage to anything nearby.
Unfortunately, this technology is still very much in its infancy, and a number of problems need to be resolved. The first and foremost is its power demands. A single pulse would require 50 billion watts, 50,000 times the power of a light bulb. Additionally, it will be necessary to make lightning devices more rugged and increase their durability for combat situations.
2. Smart Bullets
While we wait for lightning guns, we will have to depend on self-correcting smart bullets. Aiming them, especially at longer ranges, is particularly difficult, with the shooter having to take into account bullet drop, windage, and movement, while also factoring in the time the bullet will be in transit to the target. Larger, less accurate weapons could miss targets at one kilometer by as much as 10 meters, if not more. The smart bullet drops that distance to about 20 centimeters with its integrated sensor, routed to a processor which calculates course corrections 30 times per second and adjusts the bullet's fins. A laser designator guides the bullet to its intended target, which could be up to two kilometers away.
Matter teleportation is a trope of the science fiction world and, for a time, thought to be impossible. However, developments in the understanding of quantum physics have allowed for the transportation of information from one atom to another, giving rise to the possibility that, one day, people may be able to transport from place to place.
Teleportation is made possible by entanglement, which synchronizes two particles regardless of the distance between them; if one changes its state (such as its polarization, spin, etc.), the other will do so as well. Scientists have successfully entangled particles and have successfully transmitted information, such as binary digits, through these particles.
However, this is a far cry from transporting a human (with its estimated 10^29 particles). Thus far, scientists have successfully transported information across 100 million particles with a 90% success rate, but it is believed this could be improved. The greatest hurdle remains the fact that a teleported object would be destroyed and then reconstituted at the destination, which may be unbelievably painful. It could also destroy the person's consciousness and, thus, defeat the purpose of teleportation. Nevertheless, it remains a step in that direction.