Friday, April 22, 2016
Saturday, September 17, 2011
What is nanotechnology?
Nanotechnology is the study of manipulating matter on a molecular scale. In general this field deals with structures sized between 1 to 100 nanometers (nm) in at least one dimension. . In 1974 Tokyo science university professor Norio Taniguchi defined the term “nanotechnology” as follows; 'Nano-technology' mainly consists of the processing of, separation, consolidation, and deformation of materials by one atom or by one molecule."
Nanotechnology is not just a single technical approach. It is a scientific basis for various possible new propositions. For example fields like nanomechanics, nanoelectronics and nanophotonics are new fields which have evolved on the scientific foundation of nanotechnology. As shown above it covers a vast range in science from mechanisms in the conventional physics to absolutely new methods based on self assembly of matter. Nanotechnology deals directly with developing new materials within the nano scale and investigate possibilities and methodologies of controlling matter on the atomic scale.
Unknown history of nanotechnology.
The concept of nanotechnology was first expressed in “There’s plenty of room at the bottom”, a speech given by physicist Richard Feynman at an American physical society meeting at Caltech which was held on 1959. In this speech he described about development of methods to manipulate individual atoms and molecules.
In 1980’s the basic idea of nanotechnology was explored in much more depth by Dr. K. Eric Drexler, who promoted the significance of nano-scale phenomena by the means of speeches and books such as “Engines of Creations: The Coming Era of Nanotechnology” which is considered as the first book on nanotechnology.
Major advancement of the nanotechnology was accompanied by two major moves in the science; the origin of cluster science and the invention of scanning tunneling microscope (STM). This led to the discovery of fullerenes, which are the molecules composed entirely in carbons, in the forms of hollow sphere, ellipsoid or tube, in 1985. After few years carbon nano tubes which is a special type of fullerene was discovered.
Concepts of nanotechnology.
There are two main concepts in nanotechnology; the “bottom-up” concept and the “top-down” concept.
In the “bottom-up” concept, materials are built from molecular components which have the ability of assembling themselves chemically under the principles of molecular recognition and bond formation. DNA nanotechnology and chemical synthesis are based on this approach.
In the “top-down” concept objects in the nano scale are constructed from larger entities. The “top-down” concept doesn’t involve any control of the formation of nano bodies at the atomic level.
In this scenario scaling issues would arise from changing the magnitude of various physical phenomena.
While approaching the nano scale, properties of matter greatly changes from their properties at the macro or micro scale. Therefore at the nano level unique behaviors can be observed in the matter. Nanotechnology is about creating, studying and manipulating these special behaviors in a desired manner. By controlling these unique properties, never imagined tasks could be achieved. For example at the nano scale clay bricks are able to transmit electricity which they are completely unable to do at the macro scale. As a result we will be able to transmit electricity through specially laid paths of nano-bricks inside the walls instead of using metal cables.
Manipulating matter at the nano scale is a main focus in the field of nano science. Because all the future achievements in nanotechnology is based upon those handling methods. Without the proper and adequate control, as everything, nano materials can act in a hazardous way, that they may harm both living and non-living bodies existing. Therefore before approaching the sophisticated creations in this field, scientists should research on the basic behaviors of nano material and methods to manipulate them. That will help us to develop an effective technology.
Applications of nanotech.
Applied nanotechnology spreads in a wide area. Some scientists say nanotechnology will replace each and every existing technology on earth. By now most of the branches of science have their own subcategories of nanotechnological approaches, like nano-medicine, nano-chemistry and nano-robotics. One way of categorizing these numerous applications are according to the fundamental nano materials which have been utilized in those applications. There are three main fundamental components; Nano-surfaces, Nano-particles and Nano-tubes.
Nano surfaces are surfaces with nano scale impressions which are developed by special treatment processes. Effective surface area (a) of nano-surface is extremely higher than a similar area of normal surface. Therefore unique features can be observed in nano-surfaces. For example, if we use a nano-surface as an electrode in a electrolyte fuel cell, since the electric current (I) generated by the cell is proportional to the surface area of the electrode (I α a), with the increased surface area of the nano-electrode, higher electric current can be generated. On nano-surfaces we will be able to build nano-chips with relatively high capacity and smaller solar panels which can harvest higher solar energy. Since nano surfaces have nano scale cavities they will trap almost all the particles and microbes thus nano surfaces can be used as highly effective filters. If the cavities are so small that nothing can enter them, then nothing will be able to make contacts with the surface. So those nano surfaces can be used to develop self cleaning roofs, walls, tiles, glass and even garments.
Nano-tubes are tubes which range within 1-100nm. They are usually developed by rolling around an atomic layer in the shape of a tube. Nano tube is a main part in nano-motors and nano-rotors. They can also be utilized as transporters when the ends of the tube are closed. Nano scale conducting lines can be constructed by attaching a series of nano-tubes at ends. Key component in nano wires and nano diodes are these nano tubes.
Some of nano particles and nano tubes belong to the universal group known as fullerenes. Fullerene is a general name given to hollowed structures developed by carbon atoms. Those structures either can be spherical or tubular. Spherical fullerenes are also known as Bucky-balls, which is a fascination in the field of nano science.
Even though humans invented it and developing it, in an one particular instance it will go out from human control to its own control, because principals of self assembly have been used from the very first initiation to create it. The results of self control is beyond our imaginations. Therefore even though it is not comfortable, we should know that future of this field is unpredictable. But as human intellects we can make some good speculations about the future of nanotechnology.
Nanotechnology beyond control can be a great danger. They can be categorized as primary impacts and secondary impacts.
Primary impacts are the damage directly done by the technology; nano-robots if not programmed well or if not under proper control can cause serious problems, enter living organisms and start destroying the cells by various mechanisms such as destroying proteins and mutating genetic material, change the electric sequences of the neurons and damage the brain thus resulting mental and physical disorders. Some of these can be lethal. Nano compounds can cause various incurable diseases.
Secondary impacts are the damage result through the primary impacts; impairments of mental and physical health will lead to social and behavioral problems, mutations in genetic material will result in new species which either can be good or bad.
Since the nano materials are super efficient, invisible to the naked eye and easily spreadable through any medium, without controlling methods, they can easily cause an invasion. Therefore if we are going to advance this technology, we should first research the fundamental properties and controlling methods of them. Then we should apply those methods to the technology in order to minimize the damage potential. We should also assess the technology all the time on their practical application.
But still we can’t assure a 100% harm free technology. Because nanotechnology at their higher stages will develop their own mutated properties which we still do not know. At that moment we will be defense less in front of our own technology. That is why it is so important to study all feasible behaviors of nano materials and systems. That will grant us a secure, practical and an effective novel technology.
Saturday, March 19, 2011
Today the moon which is the only natural satellite of earth is travelling in an orbit around the earth which is lying closer than usual. Normally moon goes around the earth in an orbit which is having a mean radius of 385,000 km. Moon will go 50,000 km closer to the earth today. This incident previously happened in 1993 and this will happen again in 2029. In case of this, due to the influence of moons gravity, high tides and various changes in the earth's atmosphere which will lead to changes in earth's weather is possible.
Saturday, December 4, 2010
Science can explain many things which happen in our universe. With the help of mathematics and physical theories science has got that ability. Most of the existing scientific explanations are based on three dimensions that you probably already aware about. Those are Length, Width and Height. Using these three dimensions we can explain a physical object or identify something like distance or volume. Knowledge about this three dimension concept would be enough for an day to day ordinary life. But when you take, life span of an object , molecular mechanics or radioactive decay in to account the crack appears in this concept.
No one can explain how things get old or more scientifically, increasing the disorder in a system, using the three dimension concept. Then the question rises, are there any other dimensions except length, width and height? If we count time as a dimension, it will give answers to lots of questions like this. But many people, including scientists reject to consider time as a dimension. They say that time cannot count as a dimension, because it is not constant. But they should also remember that three dimensions are also not constant. Nothing exist in this world is constant, everything is relative and changing with the time.
Time, the fourth dimension is different from classical three dimensions in various ways. Three dimensions can be detected by sensory organs such as human eye. But time could not be detected by those kind of organs. We can move through space forward and backward. Through the time you can only move forward. Backward movement is naturally restricted within the fourth dimension. For example feather in a river only move downward along with the water and never move upward. But if you give enough force against the flow of water you will able to move the feather upward. In the same way, if you supply the required environment and enough amount of energyin the proper state you might able to move something or even yourself to the past through time.
The challage which lies in front of present scientists is to figure out what is this required environment and what is the proper state and the amount of energy which is required. The day which humans find answers to these questions will be the turning point of human civilisation and it will be the start of a new science era.
Saturday, April 24, 2010
Last 14th of April, 2010, EyjafjallajÖkul volcano located in Iceland erupted after a devastating earthquake and it was noted as the second largest eruption of 21st century. There was another earthquake close to that area on 20th of March. The second earthquake which occurred on 14th of April was 10-20 times bigger than the previous one. Before this recent eruption this volcano erupted several times during the period between 1821-1823.
Iceland sits on a volcanic hotspot in the Mid-Atlantic ridge. So, frequent eruptions occur in the area. In this recent eruption, about 6 km high ash clouds threw up in to the atmosphere and those ash particles have spread in a vast area.
There was a similar incident occurred on 15th of June, 1991 in a area called Luzon in Philippines. The Pinatubo a stratvolcano erupted after a chain of earthquakes, throwing 20 million tons of SO2 and ash particles in to 20 km up in the atmosphere. This SO2 and ash clouds had caused many changes in the global climate for a long period. Because of those ash clouds, average temperature in northern hemisphere decreased in to 10 centigrades. Also northern hemisphere had reduced temperature from 0.5-0.6 centigrades and entire planet was cooled from 0.4-0.5 centigrades. This was the first time scientists experienced such a thing in near history and they called it global cooling or cooling effect. As you may think, Yes, it is the opposite of global warming. There is no wonder, if you are amused.
There is just a simple scientific explanation for this. The SO2 gas eject from the volcano react with water/H2O(g) in the atmosphere and form Sulfuric gas/H2SO4(g). Then Sulphuric gas turn in to Sulfate aerosols. These particles can last for 3-4 years in the upper part of the atmosphere (Stratosphere) and have the ability to absorb terrestrial radiation. And also sulfate aerosol and ash particles reflect extraterrestrial radiation back to the space. This scientific phenomena is known as the “Radiative Forcing”. Because of that, temperature in lower part of the atmosphere (Troposphere) will reduce.
In green house effect, greenhouse gases reflect terrestrial radiation back to the earth’s surface and absorb extraterrestrial radiation. So, we can say without any doubt that, this is the opposite effect of green house effect, the cooling effect.
The same thing can happen again now, because of the large amount of ash and SO2 ejected to the atmosphere from the eruption occurred in Iceland. So this incident could bring back the issue again. But, there is much less chance to get a solution from this scientific phenomena for global warming.
Thursday, April 1, 2010
Science is an art. But most of the people do not recognize the feature. There is a complicated connection between science and art. May be the complexity is the factor that keeps the reality unrevealed.
There are many questions that do not have any answers. Sometimes the answers are not well defined or out of the track. It is a natural thing, because we find solutions for any matter through our brain. Though human brain has the maximum capacity among all animals, it is not capable of achieving everything. But definitely we know that ultimate organ build from billions of neurons is capable of something. Beside those capabilities we will not be here. However, the questions that do not have answers, one of those questions is “When did science appear in the universe?” and another one is “When did art appear in the universe?”. In this scene every mastermind is speechless. But we can say both of them appeared together. Someone may find that this is a tricky answer, but we should assume that some questions do not deserve answers.
The key for the link between science and art is inside our body. The human brain is divided in to two hemispheres, as the right hemisphere and the left hemisphere. The right part of the brain controls the left side of the body while the left part of the body controls the right side of the body. Scientific researches have proved that right part of the brain is responsible for artistic activities conducted by the person and the left part is responsible for scientific activities done by the person. But there are no strict rules inside the brain. If left hemisphere is unable to supply information for science based activities, right hemisphere will develop areas itself to achieve the goal. The process is same when there is a failure in the right hemisphere. According to above mentioned facts right and left parts of the brain do not act separately, they act as a one united system. As we cannot divide the brain systematically we also cannot divide its influences. So how can we tell science and art are separate fields. Both of them are components of a single field, it is the field of life.
Through the human evolution both science and art developed together. Many people lived in the past who are now days famous as major figures in science were actually also involved in art. They made their inventions and theories using their creativity and they mastered their creativity through their artistic activities. Creativity is the base for science. Without creativity or curiosity science would not exist. If you take a look at the history of science field you will see lots of examples. Leonardo di ser Piero da Vinci popular as Leonardo da Vinci who lived in Italy between 1452-1519 was an inventor, painter, sculptor, architect, musician, scientist, engineer, anatomist, geologist, botanist, mathematician and a writer. He painted the world famous paintings such as Mona Lisa and The Last Supper that became unsolved mysteries in the art history and many other marvelous paintings. He also dissected human body and drew many anatomical sketches and he also made primary sketches for the inventions such as helicopter, hang glider and hydraulic pump. So he is a brilliant example for the relationship between art and science.
Many people believe that if you need to become fluent in science you should give up in art or if you want to become an artist you should give up in science. How can a scientist without creativity, plan an experiment or make a model? How can a musician without basic scientific knowledge about sound compose a melody? Forcing people to do only scientific studies or only artistic work is useless, because art and science are both normal human natures. It is acceptable that some people become atypical in some fields, because they dedicate themselves to those areas. But that does not mean they are unable to improve in other fields.
The link between science and art is unavoidable. Without art, science could not exist, without science, art could not exist and without both science and art, world could not exist.
Saturday, November 28, 2009
Is there any kind of life out side of the earth? This is a question to everyone. Some people say there could be life outside of our planet and some say there couldn’t be life in any other place in universe other than earth. There are reasonable facts for both answers. But no one has proved them.
Universe is an infinite space. We have to believe it because we are still unable to travel through the whole universe. If universe is infinite, there could be many galaxies. Most of them may be even larger than our galaxy, the Milky Way. So there could be so many solar systems and also many planets. So how can we say that there are no such planets like earth in this universe? There is a huge possibility of having those kinds of planets. If those planets have water, minerals, temperature that is suitable for life and an atmosphere with sufficient gases there could be life on them.
According to human knowledge there is a temperature range that is precise for living beings and there are basic elements which can form living bodies. There are also some gases that living animals can use for breathing and some energy sources which can use as energy supply for living bodies. But all these are limits followed by present human knowledge about life. Why couldn’t be there a life which is entirely different from the life on earth?
People believe that carbon is the best element for living structures. But silicon can be a good alternate element for that. Carbon and silicon belong to the group IVA in the periodic table and elements belong to the same group have similar natures. So it could be possible of having living bodies made of silicon. Scientists had already found animals consisting silicon, in the earth. Diatoms that belong to the phylum Chrysophyta are photosynthetic, unicellular organisms with unique double shells made of opaline silica which are often characteristically marked. So they are called as the jewels of the living world.
Oxygen is considered as the breathable gas for most of the living beings on earth. Living bodies are designed to generate ATP (Adenosine Tri Phosphate), the compound which can store energy of chemical compounds such as glucose, amino acids and lipids. The energy in those compounds is transferred to ATP through a process happen inside the mitochondrion of live cells. Oxygen is the molecule that catches the last hydrogen atoms released by this reaction series. Oxygen acts as the dehydrogenator in this process. There could be molecules instead of oxygen, which are capable of combining with the last hydrogen atoms. We should remember that we have found only a little amount of elements. So there could be many elements in this planet that are not recognized or found yet. In the universe there could be more. We will never find most of those elements in earth. Some of those elements could form a molecule that can efficiently catch the last hydrogen atoms. Therefore oxygen could not be the only dehydrogenate molecule.
When we take the temperature range that is considered as suitable for life in to account, we get the same results as carbon and oxygen. We prefer this is the suitable temperature range for life because we experience it on earth. Temperature range suitable for a living body is selected by the nature, mechanisms occurring inside the body and chemical structure of it. But we should not forget that chemical structures can be varying in different situations. So there can be life in very cold places and also in extremely hot places. Today scientists have found life in cold ice cores and even inside volcanoes. So we have got some evidences even from our world. Therefore, theoretically it is logical to believe that there is life outside of the earth.