The History and Potential Uses of Hydroponics

Hydroponics is the science of growing plants without soil. History shows us that this is by no means a new concept. In ancient times the hanging gardens of Babylon, the floating gardens of the Aztecs of Mexico and those of the Chinese were all early examples of ‘Hydroponic’ culture. Egyptian writings dating back to several hundred years before Christ have descriptions of the growing of plants in water.

During the 1930s, scientists experimenting with the growing of plants without soil, using nutrients dissolved in water, discovered that the soil was needed only as an anchor for the plant’s root system. Since that time more and more research has resulted in the development of commercial nutrients and purpose built systems of differing types. Hydroponics is now popular in Western Europe, Australia, Canada and many other areas of the world.

As technology advances more and more of the world’s food is produced using hydroponic methods. Although rooted in history, it is still a relatively young science, Hydroponics has progressed rapidly over the past half century, it has been adapted to suit many and varied situations from outdoor farming to greenhouse production and now also indoor home cultivation. The military use it for growing fresh vegetables in submarines and the space programmes are even experimenting with Hydroponics to feed the crews on board manned space stations

The potential use of Hydroponics for future cultivation is enormous. It is already being looked at for increasing the food production in underdeveloped countries where space can be a factor. Because it is feasible to grow in areas of poor and even barren soil, arid regions of the world such as deserts could be utilised to grow crops hydroponically. The desert sand could be used as an ideal growing media and the nutrients even mixed with sea water, once the salts have been removed.

Even in countries with a more temperate climate Hydroponics can be used for food production, the temperature being maintained with the use of modern grow lights.
In Holland and other European countries the production of vegetables, such as Lettuce and fruits, like Tomatoes is showing that Hydroponic methods can be very effective and cost efficient. A large proportion of this produce is now being grown that way.
Some 20 plus years ago racehorse stables in the U K were looking at production of highly nutritious barley and wheat ‘grass’ as a feed. It was then very expensive and in its infancy, however today a large number of horse owners feed there animals in this way. It is also not unheard of for farmers to use the same methods to feed their cattle during the winter periods when the fields are too wet to graze.

With the advent of more efficient methods of production the uses of soil-less culture will advance and multiply as more people experiment with the systems available.
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Newton’s three laws of motion are so integral to everything around us that many people take them for granted. Young children achieve a basic understanding of these laws as they interact with the world around them, but older children, teenagers, and even adults can achieve a deeper understanding and an appreciation for these laws through model rocket kits. This article explains how a school project using Estes model rockets can be used to teach Newton’s second law of motion.

Newton’s second law of motion states that force is equal to mass times acceleration. These may sound like scary “physics” words, but do not let that overwhelm you. Let’s apply these terms to rocket kits.

Force is a power or energy exerted on an object. When that force is exerted, the object will exert a force of its own in return. With perfectly balanced forces, nothing in the situation will move. This is known as a static situation. Imagine pushing your hand against a brick wall. When your hand exerts a force on that brick wall, the wall “pushes” back with an equal force, and nothing moves at all. This situation is examined in Newton’s third law.

However, in a dynamic situation, the forces are unbalanced. This means that the force exerted on an object and the force returned by the object are not equal. Because these forces are not equal, the object will move. Model rocket kits offer a great way to demonstrate this law.

Mass is the scientific term for all the “stuff” that makes up an object and is measured in grams. On the surface of Earth, mass and weight are generally treated the same way. However, outside of Earth’s gravity, an object will have the same mass but will clearly have a different weight.

Anytime the speed of an object changes, the object accelerates. If the object moves at a greater speed, this is known as positive acceleration. If the object moves at a lesser speed, this is known as negative acceleration (or deceleration).

All of these forces can be seen in the motion of Estes rockets. Prior to the rocket’s launch, the rocket will be in a static situation where the forces are balanced. When the fuse is lit, the fuel will burn and will produce force that propels the rocket upward.

The rocket’s mass can be measured prior to a launch. Estes model rockets with more or less mass will react differently to equal amounts of force and acceleration.

The rate at which the speed of a rocket increases (or decreases) is the rocket’s acceleration. Different engines and differing amounts of fuel can be used create differing amounts of acceleration. Model rocket kits provide a great illustration of different amounts of acceleration.

The effect of force, mass, and acceleration on the path of a rocket can be varied with different types of Estes model rockets, different types of engines in the rockets, and differing amounts of fuel. These “experiments” can be repeated to analyze the effects of more or less force, mass, or acceleration.

Model rockets are an entertaining way to gain a deeper understanding of Newton’s laws of motion. Rather than being a difficult or boring experiment in a lab, model rockets encourage a student’s sense of adventure. Experimenting with model rockets provides an entertaining forum to analyze these ideas!
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Space themed birthday party is not difficult to organize. Depending on your budget, a number of great ideas can be put into place. The idea is to capture the interest of the children and keep them entertained. Games with a space theme can be included too.

Children love moonwalk race, space themed treasure hunt or scavenger hunt. A contest to build his or her own spaceship would also be interesting. If the party is held at night the ambiance can be further enhanced by putting up glow in the dark stars or glow in the dark posters of the universe and beyond. Different planetarium devices that can be used to show different space element can also be set up in the part of the home where the party is taking place. Some of the more advanced planetarium devices come with a CD that will give the children a tour of the cosmos.

Another activity would be the making of space rocks by the children. Give to the children small pieces of rock and plenty of washable paints so that they can paint the rocks in whatever colors that strike their fancy. However if you intend to let them do painting, then do let the parents of the guests know in advance, just in case the parents want their children to bring a smock.

Space trivia is a fun game for children. Remember to get ready prizes for the team that can answer the most questions and thus declared the winner. In this way, entertainment is combined with learning. For kids who are creative, hand out paper plates, crayons, markers and other craft supplies and encourage them to make their own space masks. Give a prize to the kid with the most impressive one.

Science fiction and facts about space can give us a lot of help in the planning of the party. Children can be given an option to try the different kinds of space food that is available to astronauts. This is both educational and fun. Children can learn what foods are eaten in space and why the astronauts cannot eat regular and traditional food in space. Some foods, such as brownies and fruit can be eaten in their natural form. Other foods require adding water, such as macaroni and cheese or spaghetti. An oven is provided in the space shuttle and the space station to heat foods to the proper temperature. Explain to them that there are no refrigerators in space, so space food must be stored and prepared properly to avoid spoilage, especially on longer missions.

Condiments such as ketchup, mustard and mayonnaise are provided. Salt and pepper are available only in liquid form. This is because astronauts cannot sprinkle salt and pepper on their food in space. The salt and pepper would simply float away and pose a danger because they could clog air vents, contaminate equipment or get stuck in an astronaut’s eyes, mouth or nose. Drinks range from coffee, tea, orange juice, fruit punch and lemonades. By including the explanation about these facts, children will not only learn and enjoy your space themed party but will even have stories to tell when they go home.
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