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From the very ancient times dating back to the ancient Greek civilization, man has been constantly on the lookout of tools that could reduce the amount of effort required to carry out operations such as pushing, pulling and lifting heavy objects. Traditionally, machines have been divided into two categories: simple and complex.

Simple machines are tools that make work easier. They have few or no moving parts. These machines use energy to work.

There are only six simple machines: the lever, pulley, wheel and axle, inclined plane, wedge, and screw. Complex machines, on the other hand, are made up of several simple machines, and are used to perform complex tasks that are not possible to do by humans. For instance, a crane is a complex machine using the many simple machines like the pulley and lever (the arm of the crane), and is used to lift very heavy objects.

As mentioned before, levers are simple machines. A lever is a board or bar that rests on a turning point. This turning point is called the fulcrum. An object that a lever moves is called the load. The closer the object is to the fulcrum, the easier it is to move.

Now, all of us have loved playing on a see-saw swing with our friends or siblings, but did you ever think that a see saw is nothing but a simple lever? A see-saw (or teeter-totter) is a plank of wood, the center of which is hinged on to a bar - the fulcrum. It moves up or down around this rod.

While playing on it, you would have noticed that the heavier person between you and your friend was pushed down as you rose up in the air. Moreover, by applying a little force on the see-saw, you were able to lift a heavier person, thus greatly reducing the amount of effort required to lift the heavier person. To realize the difference in the effort required, try to lift your friend in the air by grabbing him physically.

Another example of a lever is a bottle opener. As you would have seen, it is extremely tough to open a glass soda bottle by hand. By using a bottle opener, we are magnifying the force applied and thus reducing the effort required to do the job.

A similar example can be seen in the form of a hammer which is used to pull a nail out of the wooden block.

Levers are divided into three classes, depending on the location of the fulcrum. A first-class lever is a lever in which the fulcrum is located between the input effort and the output load. Example: see-saw, hammer’s claw etc.

In a second class lever the input effort is located at one end of the bar and the fulcrum is located at the other end of the bar, opposite to the input, with the output load at a point between these two forces. Example: Door knob, wrench (used by plumbers and mechanics).

In third class levers, effort is applied between the output load on one end and the fulcrum on the opposite end. Example: Baseball bat, broomstick, etc.

In the modern world we use levers all the time, and usually don’t even realize how much easier this simple machine makes our lives.

Sara Jones was a fine student but science was a source of frustration she didn’t want her kids to suffer. She met Rick and Amanda Birmingham and realized their grasp of everyday science was the secret to making science fun. To learn more about the solution to science stress visit www.SuperFunScience.com

I am fortunate to be living in a region of Australia with one of the richest Aboriginal cultures and a living history. North East Arnhem land in the Northern Territory is located at the confluence of the Arafura Sea and the Gulf of Carpenteria. As an Avid Astronomer I am always on the lookout for an opportunity to share the night sky with others. This day the two came together in a beautiful symmetry.

Sharing the delights of North East Arnhem land with Visitors is always a satisfying experience in it self. A crystal clear stream teaming with beautiful fish, bush land alive with the sound and movement of tropical birds and lunch shared with friends really sets the scene well.

Follow this up with a lazy afternoon on a white sandy beach cradled by Ochre red cliffs with a backdrop of Coastal Rain forest and you have to wonder can it get any better than this!

The final stop for the day was to be the open Coastal plain known as Macassans (local spelling) Beach. Fringed with Casuarina trees that seemed to sing in the wind, as the dry season sea breeze whistled through their pale green pine like leaves.

To put you in the picture, the Aboriginal people of NE Arnhemland are called the Yolngu People, The Language is Known as Yolngu Mata. Not all the words in their language originate from our shores though. The Makassan people of Sulawesi (now part of Indonesia) had been trading with the Yolngu people 200 years before Australia was even colonized by Europeans. The Makassan’s have had a material influence on the Yolngu People including the addition of many words to their already rich language.

We had just finished looking at the “Macassan” stone drawings, a very significant site for the local Yolngu people.

I looked up (as you do often when you are an astronomer!) and there the IIS was, high overhead and bright as can be. The ISS was traveling from North West to South East and was as bright as the Planet Jupiter. It was only afterwards that I made the link with the Makassan people sailing on their annual trading journey to the Yolngu homelands in NE Arnhem land, coming from the northwest into the southeast . Just as the ISS had done before our eyes, high above the stone pictures of the arriving Makassan ships, laid down in the late 18th Century!

What a contrast the ISS is to the Makassan sailing ships of old that plied a trade with the Yolngu people 200 years before Europeans were even in this country, let alone flying through space.

Yet the similarities are still there, people of different races bought together through a knowledge of the stars. For surely the Makassan ’s must have navigated their way here by the position of the stars and the Yolngu people anticipated their arrival by their own celestial calendar. Just as the ISS brings people of all Nations together in the pursuit of Space Science, as we work out our own place in the universe. With ever more accurate distances plotted to stars in our galactic neighborhood and an insatiable desire to discover a habitable planet around another star.

The “Macassan” Pictures and the passage of the ISS was a real treat for everyone present and one that will be remembered for a long time to come. Keep looking up, you never know what you might see!

Ian Maclean: Author, Presenter and Science Show host
Discover the night sky’s hidden secrets for yourself at
http://www.nightskysecrets.com
Hear podcasts from my weekly radio show The Science Hour, all the latest science news at
http://www.askthescienceguru.com

Almost all of us are acquainted with lasers, as we have used or seen lasers in action at some point of our lives. Lasers are used in a variety of places, like for pointers for a presentation in a corporate boardroom classroom or as a cat toy.

A closer example at home is the usage of lasers in the CD players, where a laser is used to read the information stored in the CD. A recent breakthrough in this field is BLU ray discs, in which a high intensity laser is used to read ultra high capacity discs.

Lasers also find intensive application in fields such as holography (holography is the art of etching a three-dimensional image onto a material using lasers - the type of laser depends upon the material to be etched). Apart from this, lasers are used by the military in many of their programs, to correct eye disorders by LASIK surgeries, and in industries that use dangerous chemicals to detect leakage.

So that’s what they’re used for, but we haven’t answered the question of what a laser actually is. LASER is an acronym that stands for Light Amplification by Stimulated Emission of Radiation. Now what this means is that lasers are basically tiny particles which are radiated, and these particles are converted to laser beams by manipulating them by a number of means.

Unlike white light which is made up of seven colors - ROY G BIV, or red, orange, yellow, green, blue, indigo, and violet, the seven colors which form the rainbow, lasers are usually made up of monochromatic (single-colored) light. This is because white light spreads out as it travels, but monochromatic light is almost non divergent, that is it does not spread much even after traveling large distances.

This increases the range of the laser light. Moreover, normal white light will refract (bend) differently when it hits an object - each color bends at a slightly different angle. Monochromatic light only has to bend in one way, so it keeps its coherence (the ability of light rays to stay together as a bundle), so the laser stays more focused.

Monochromatic light can be generated by utilizing free electrons (electrons are very small parts of atoms which are the building blocks of all kinds of matter existing in the universe). Electrons, when highly energized, give out that energy in the form of radiation before coming back to their normal state.

Specific types of radiation can be created by electrons energized to specific energy levels, giving out single colored light. This light is then focused into a single powerful beam by one of several methods, such as by using a cathode tube or by utilizing ionized air in vacuum tubes.

The following is a list of the types of lasers and their applications, and shows that lasers can be produced by different methods:

*Dye Lasers- used for spectroscopy, various kinds of research, birthmark removal, and for separating isotopes. The range of this laser can be tuned by changing the kind of dye used.

*Free electron lasers- has various medical uses, and is used in atmospheric research and material science.

*Nickel-like samarium lasers- can be used for high resolution microscopy and holography.

*Raman lasers- used in creating optical signal amplification for telecommunications.

*Nuclear pumped lasers- currently being used for research.

Lasers, if used in the right way have innumerous applications, which are growing by the day, but they can also be devastating if used in the wrong way. Of course, always be careful when using, playing with or looking at lazers (such as when you play with a laser cat toy), they can be very damaging to your eyes (or your kitty’s) if you look directly at them.

Sara Jones was a fine student but science was a source of frustration she didn’t want her kids to suffer. She met Rick and Amanda Birmingham and realized their grasp of everyday science was the secret to making science fun. To learn more about the solution to science stress visit www.SuperFunScience.com

What comes to your mind when you think of the Milky Way? Well, the Milky Way is a galaxy among the billions of galaxies in the universe. A galaxy refers to a cluster of billions of stars and other heavenly bodies, including solar systems like ours.

Galaxies are classified on the basis of the arrangement of stars - they form a shape like a spiral, disk, or sphere. The Milky Way or the spiral galaxy is home to our own solar system, and the planet Earth.

Our galaxy is called the Milky Way because of how it looks in the night sky. As many famous astronomers have said, the Milky Way looks like a stream of milky glowing stars.

The Milky Way is over 13.2 billion years old (about the age of the universe itself) and consists of about 200 to 400 billion stars. It has fascinated humans for many millennia, and will continue to do so in the future because it possesses some intriguing properties.

The Milky Way, as already mentioned, is an elegant spiral-armed galaxy. A spiral galaxy consists of a ball-shaped body with swirling arms surrounding it.

There is very dense celestial matter at the core of the galaxy, and the stars become less crowded going down the arms. Our sun and the solar system are located in one of the arms of our galaxy.

The galaxy itself rotates around its center, completing one rotation in just over 220 million years. Now that, my friends, is a very long period when compared to the earth’s rotation period of 1 day.

New reports are coming out that suggest that the common perception of the Milky Way’s structure may not be correct. However, mapping the Milky Way is very difficult, since we are looking at it from the inside, with many stars blocking views of the core of the galaxy.

New research shows that the galaxy is missing two of the four arms that it was thought to have. This research has forced most of our scientists to reconsider their perception about the galaxy. Two research teams have carried out studies very recently, giving some amazing results.

The first team used the Spitzer Space Telescope, which can see through dust and successfully map the orbital speeds of the stars. Two astonishing results that were brought out were that two of the galaxy’s four arms are in fact just small side branches, and the central core is almost twice in size that was previously believed!

The other team utilized such a powerful telescope that you may even be able to read newspaper on the moon sitting here on earth. There, the research shows that the galaxy is moving in a much different manner than what we thought it to be.

Change in the pattern of the motion leads to a change in the shape gradually, which scientists can use to backtrack and make better guesses about the origins of the Universe. It also helps us in having a better understanding of spiral galaxies like the Milky Way and its nearest neighbor, the Andromeda galaxy, and galactic motion in general.

However, it may be a long time before we can say that we have substantial information about galaxies and the universe in general, because there is so much more to learn!

Sara Jones was a fine student but science was a source of frustration she didn’t want her kids to suffer. She met Rick and Amanda Birmingham and realized their grasp of everyday science was the secret to making science fun. To learn more about the solution to science stress visit www.SuperFunScience.com/form

Resistivity is the term used when describing the specific electrical resistance of a material. Put into lay mans terms it is a measurement of the resistance of any given material to electric current; it is normally measured using a resistivity meter. A material that has a high resistivity will impede the flow of electricity greatly while those with low resistivity will freely allow the flow of electrons.

Although materials all have a unique resistivity measurement, there are certain generalisations that can be made without having to use a meter. Metals and substances such as salt water tend to be great conductors of electricity where as materials like rubber, plastic and glass are extremely resistant. Because of the low resistance of metals, and especially copper, these materials are used for electrical wiring while the materials that cover them to prevent short circuits and shocks are made of plastic or rubber. This is where the resistivity meter is used most extensively, for finding the resistance of lengths of wire in electrical devices.

The formula for resistivity of a wire that a meter automatically computes is a relatively simple equation based upon three factors. The first of these is the resistance, measured in Ohms and can be found using a table of resistances for a number of different materials. The second component of the equation is the area of the circumference of the wire. The final piece of information needed to find the resistivity of a wire is the length of the piece of wire. The equation simply multiplies the area and resistance and divides the resulting figure by the length; in terms of units of measurement the Greek symbol rho is used and will usually be present on the readout of the meter.

It is not just wires however that are measured using a resistivity meter, these pieces of equipment are extensively used in measuring rock resistivities. Naturally rocks are not going to be used for electrical wiring but as the metallic minerals in rocks conduct electricity better than other non-metallic minerals, a meter is a useful tool in finding the metallic mineral content of rocks. The uses for this are vast but predominantly resistivity meters are used for geophysical exploration and more precisely the metal content of rock formations. Methods of measurement vary from surface testing to drilling holes in the ground.

These methods of resistivity measurement do not always use a handheld meter but a far larger and more industrial technique. The two predominant forms of measurement are termed as active and passive. Active measurement involves introducing electricity to the ground and measuring the strength of the electrical field created between electrodes giving an indication of resistance. Passive methods on the other hand measure the natural flow of electricity caused by electrochemical reactions between minerals and fluids.

Due to the benefits of this type of measurement the resistivity meter is extensively used in a variety of industries. The mining industries, especially those involved with the search of precious and semi-precious metals in rocks heavily use this equipment when prospecting. It is also extensively used in the oil industry. In terms of the resistivity of wires, electrical manufacturers use this type of meter to find the qualities of their components. Today it is hard to imagine a world without this type of meter, not only would there be less metals mined in the world but the electrical equipment we have in are homes would almost certainly be less well developed.

Industry expert Thomas Pretty looks into the variety of uses for the resistivity meter.

Thermodynamics is the field of physics that describes and correlates the physical properties of macroscopic systems of matter and energy by relating such qualities temperature, pressure, and volume. It also takes in energy, heat, and work. Thermodynamics was founded between 1850 and 1860 by R.W. Joule about the quantitative equivalence between mechanical work and heat.

Thermodynamics is much neater when the absolute temperature is used. Thermodynamics correlates, with mathematical equations, information relating to the interaction of heat and work. It does not speculate as to the mechanisms involved . Thermodynamics is the science of heat and temperature. It is part of physics (and physical chemistry) that was developed at the time of the industrial revolution.

Heat is a form of energy associated with the positions and motion of the molecules of a body. The total energy that a body contains as a result of the positions and the motions of its molecules is called its internal energy.

Heating the crystalline phase formed by rapid cooling causes its transformation into the phase observed by cooling slowly. X-ray diffraction analysis confirmed the existence of these two crystal phases in coenzymes Q9 and Q10 and the transformation from the rapidly crystallized form to the more ordered form associated with slower cooling rates.

Heat created externally is transfered to water in a steam generating unit or boiler. The steam carries energy to the expander (engine) were part of the heat energy is converted to mechinical energy, work. Heat-activated styling sprays, balms, lotions and mousses create exquisite looks on healthy protected hair. Meadow seed oil delivers intense, everlasting moisture and supple elasticity.

Systems already at a high temperature are less affected by increase in heat energy than those at low temperature. Systems are divided into three categories: an isolated system can exchange neither matter nor energy with its surroundings, a closed system can exchange energy but not matter, and an open system can exchange both energy and matter. The Earth, for example, is an open system, but might be considered closed if one neglected meteors, space probes, etc.

Molecular energy, mass, and momentum transport. Laminar transport of energy and mass. Molecules at interfaces with functional interfacial properties are of special interest. These interfacial molecules may have biomolecular functions at the micro and nanoscale.

Thermodynamics deals only with the large scale response of a system which we can observe and measure in experiments. Small scale gas interactions are described by the kinetic theory of gases. Thermodynamics is the study of energy changes accompanying physical and chemical changes.

The term itself clearly suggests what is happening — “thermo”, from temperature, meaning energy, and “dynamics”, which means the change over time. Thermodynamics is an empirical and phenomenological physical science concerned with the transfer of heat and the appearance and disappearance of work attending various conceivable chemical and physical processes.

Since it is a discipline that supplies science with a broad array of relationships between the properties that matter exhibits as it changes its condition, it plays an essential role in metallurgical engineering and materials science.

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