Science and technology

Today's society cannot imagine life without technology. Modern
inventions are everywhere, even now in this very room. I wear watches that use
microchip, I got electronic diary that uses microprocessor, most of us have
cellular phone. Light in this class is provided by electricity.
Long time ago there was just a man and his load. Weight of his load was
limited by his own power. Someone noticed, that there are some animals, they
are stronger than a human and are also much faster. So it was decided to
domesticate those animals (horses, elephants, donkeys, …) and let them carry
special sleights.
Another first great man's invention was the wheel. It started new age of
transport, because it was no longer needed to use sleighs. Wheeled carts could
also transport heavier loads, because of their less friction. The wheel was one of
many prerequisites for James Watt invention. Yes, I mean the steam engine.
Steam engine was firstly constructed in Britain and in started Industrial
revolution that spread to most of Europe and to USA and Canada. The steam
engine used the stretch of hot steam and transformed sliding move to rotating. It
was very powerful and cheap to run (it used just water and wood or coal).
Steam engine was used in many other inventions such as railroad, heavy
machines in industry, ships…). But it couldn't be used in planes, because the
steam engine was too heavy for that. Problem of aviation was solved later, at a
time when combustion engine was developed. This engine uses stretch of gasses
that are produced by fuel's explosions. It's more effective, more powerful, less
heavy, smaller but also more expensive. No longer is needed to carry so much
coal, because combustion engines use liquid or gas fuel. Combustion engine
started new generation of vehicles used for personal transport. They are called
automobiles (cars). Also planes have been equipped with c.engines and the
quickly became the most powerful weapon in army.
Combustion engines can be divided into two main groups: Ignition (use
petrol or LPG) and inflammable (also called Diesel - they use oil). LPG is new
kind of fuel for ignition motors and it's very advantageous. Re-making the motor
for this fuel is very expensive but after these changes are made the engine can
use both of those fuels and using the LPG has half costs.
There are another four engine types. They're not used in cars, but are also
very important:
Reactive - used in planes (it uses the Physical rule of Action and reaction;
hot gasses are flowing very fast from the engine and that makes the engine move
forward. Those gasses also activate another mechanisms for cooling and taking
oxygen from surrounding air.
Rockeet - same as the reactive engine but it has it's own resource of
oxygen and it can run everywhere (also in water). It's more faster than the
reactive engine but it takes also much more fuel. This propulsion is used for
spaceships and missiles.
Nuclear - silent, most effective, powerful, long lasting. Disadvantage of
this engine is it's price, necessary cautious handling, and problem with used
nuclear fuel. It uses the same technology as the nuclear plant (nuclear fission).
It's used in submarines and some heavy battle ships.
Solar - it takes the energy from sun that's shining loads of electrons. It's
not used in any of conventional vehicle and it can't be used as a power plant,
because of unstable weather. This kind of power is used just in spaceships,
satellites, etc.

Computers are the most important invention for the last generation. They
are now used everywhere. They were constructed for helping people to do
routine jobs (counting, writing, printing). You can play games, view pictures,
photos, videaos, listen to music… Talking about actual use of computers has no
sense, so I'll have some words about the phenomenon of last years: THE
INTERNET.
The Internet is a global worldwide net of computers, where anyone can
access anyone's presented information (pictures, videos, programs, etc.), in very
short time. It's not important, how far is the computer, you want to access; also
the costs are the same. Internet provides revolution-mailing system, called the E-
mail (electronic mail). E-mails are short or long messages, that you can send to
anyone. E-mail is the fastest solution of conventional kind of sending
information, because in optimal case the mail can reach it's addressee on the
other part of the world in seconds…

Science and technology is (at least for me) the most important part of man's
doing. It will be also my future career.