Hobby products of every kind
In this online presentation you find links to collections of
every type of hobby products, for example all kinds of radio controlled
vehicle models. There are also many products that can be used both in your
hobby activities and as professional devices, for example the electronic
components, binoculars, microscopes and night vision devices. This presentation is however most focused on radio controlled boats.
Further down there is an article about dragons and chupacabras, and one about how a boat can float and ballance and how a subnarine can float, dive and rise in the water.
Good general online hobby stores
At these sites you find radio controlled boats and all other types of RC models. There are also other types of hobby items, like airsoft guns and hobby science.
This is a general online store with a huge inventory of tchnological products, rc models and other hobby products. You will especially find hobby products for the youngest of the kids.:
Exhibition of radio controlled boats
- By clicking at the product banners, you can read more about the exhibited models and get access to the whole
inventories. There are replicas and specially designed hobby boat models. You find boats that are electrically driven and driven by nitro
motors. There are boats for speed race and boats for a more moderate play.
You can find models suited for all ages and experience levels.
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Super Fast Formula 1 Remote Control (RC) Hydroplane Boat Super Fast Formula 1 Remote Control (RC) Hydroplane Boat |
Some scientific information for our visitors
How does a boat, ship or submarine float or ballance
When someting is submerged into a liquid, for example water, it will feel a force upwards, called buoyancy, that i equal to the weight of the water that is displaced.
A ship will float because the weight of the diplaced water gets equal to the weight of the whole ship allready when the ship is partly submerged. Or said in another way: An amount of water with the same volume as the ship is heavier than the ship.
Usully a boat is light enough because the inside is in gret extend empty, exept for air, even when loaded. Another way of keeping the ship light enough is to make it of materials that are less heavy than water with the same volume as the materials.
A submarine can float or dive by regulating the weight of the vessel. This is usually done by pumping water in or out of containers. When the submarine lies stable at some dept, the weight is kept equal to the weight of the water it displaces. When it shall rise towards the suface, water is pumped out so that the weight of the vessel is less than that of the displaced water. When it descends water is pumped in so that the vessel gets heavier than the water displaced.
A ship must not only float, but it must also keep itself upright. The usual way of doing so is to let the bottom be much heavier than the upper parts. then the ship will ballance in the water, and if it comes out of ballance, it will automatically rise againg to an upright position. A well ballanced ship can theoretically be turned around and still go back to an upright poition, as long as it is tight.
Another way of holding the ship upright, is by making it very broad with a flat bottom, or with several keels, like a catamaran or trimaran. In that case the forse needed to turn the boat around is so grat that it hardly will happen any time.
Dragons and Chupacabras are A reality
Modern scientists are generally laughing about the belief in dragons by people in older time. But if we stydy what properties people actually attributed to dragons, we easily see that the word dragon was used about reptiles that in fact existed in former periods or still exist.
First of all, a dragon has a reptile-like body with a more or less long neck and a long tail. Furthermore the dragon was thought off as a predator with a specific behavior of luring at the pray and then swiftly plunging foreward and caching it. A dragon has a clefted red tongue, and usually has the ability to spit fire. It has shells and usually a comb running along the top of the neck and back. The size can vary from small to very big. In addition a dragon is thought to have wings, usually fairly small however.
You can find reptiles with all these properties, except the ability to spit fire. But reptils have the habit of sticking out the clefted tongue and waving it so it looks like a flame.
A big and dangerous reptile, called the comodo varan, living on islands in south east Asia, has all these properties, but lacks wings.
Another reptile, the so-colled flying dragon or Draco volans, living in south America, also has wings in addition, and can glide from branch to branch of trees. This reptile is small however.
And of cource many extinct reptiles conform to the definition of a dragon, and fairly intact scheletons of these have been found so people knew about them, but could not decide if these still were living some place or not. Usually people thought so, but that thought was not stupid.
Another type of dragons can be mutated individuals, mostly reptiles, but perhaps also mamals. The evolution goes along because of mutations that make an individual different from its parents. Most of these mutations make the individual weaker or are neutral, but sometimes mutations make the new individual stronger and more fit. Sometimes the mutations is of such a kind that the a new species emerge. But for a new species to proceed, a mutated individual of one sex must find a similarly mutated individual of the opposite sex, and that happens seldome.
Perhaps a specific set of mutations occur with some frquency in certain species, that actually produce a dragon. Since they do not find any mate of the opposite sex, they stroll along lonly praying on other animals or even humans and are sometimes seen, but might also sometimes behave friendly. Thus the myths about gruesome dragons that abduct girls and children, or friendly ones, can be a reality, but these dragons are produced by specific mutations that occur at randomn intervals in certain species.
These mutated individuals will not always be called dragons. In mid America and south USA there are a lot of credible reports about reptile-like individuals called chupacabras, that pray on cattle and have the habit of sucking bloood. These are variously described, so they might occur as a result of a set of specific mutations in several species, most probably mammals, though. And sometimes these mutations produce something that actually is a dragon.
In the standard stories dragons are able to blow fire out of their mouth. Such a thing does probably not exist no and possibly it has never existed. Biologicall and physically an animal with something like these properties is still possible. The fire cannot be made inside the animal, since no aninal tissue can resist fire without damage, but some mechanism where the fire is generated just in the opening of the mouth or near its mouth is possible.
Such an animal could have an organ inside that generates a flammable gas like methane, and a channel to the tip of its mouth for the gas. It must also have something that can ignite the fire, for example hard mineralized plates at the front of the mouth that can generate sparks when clapped together. When in spits fire, it can fill its lungs, then empty its lungs and the gas organ, and clap the hard plates together to make sparks when it begins emptying the gas and air. Another mechanism would be production of two substances that can be pumped out simultanously and then self-ignite when blended in the air outside.