1 senior - DOST Sci
Transcription
1 senior - DOST Sci
SENIOR 1 S Y C O N 2 0 0 0 - 2 0 0 1 V o l . 20 T E N T ARTIFICIAL INTELLIGENCE REDEFINES MACHINES The ability to invent intelligent machines has long intrigued humans. With the advancement of computer technology, the dream of smart machines is becoming a reality. FROM ROBOCOP TO ROBODOG Since time immemorial, humans have been trying to invent the perfect robot; however, for the meantime let’s meet our newest best friend–the robodog. COMPUTER VS. HUMAN BRAIN Computers have proven themselves indispensable because of their reliable performance, but will they finally outsmart the human brain? N o . 6 S Dear Bato Balani Editor: I’m Sharon L. Manalungsung, a senior student of Holy Family Academy in Angeles City. I would like to express my warmest thanks to the staff of Bato Balani magazine for their continued support to all students. Thank you for letting us students gain more knowledge, especially in the field of science. LIQUID CRYSTAL TECHNOLOGY The “magic” behind LCDs is almost everywhere– from celfones to calculators and watches to other important equipment. R E G U L A R F E AT U R E S 3 Science & Technology News 5 Filipino Scientists and Inventors Medical Facts and Fallacies BOARD OF ADVISERS Violeta Arciaga, Jaime F. Bucoy, Jose C. Calderon, Victoria V. Cervantes, Juanita M. Cruz, Belen P. Dayauon CONSULTANT Merle C. Tan, Ph.D. 9 Livelihood Technology / I’d Like to Know DIWA OFFICERS 10 Cyber World 14 Earth Care Lourdes F. Lozano Executive Editor Amada J. Javellana PsycheR.MenodozaManaging Editor Executive Vice President 16 Investigatory Projects Enrique A. Caballero, 19 Pseudoscience 23 More Activities to Do Alfie “eLf” V. Mella Magazine Editor Virgie Naigan Art Director Reynaldo M. de la Cruz, Jose Valeriano P. Linay Cover Design William S. Fernando, Jose Valeriano P. Linay LayOut Design Jose Maria T. Policarpio, Elma L. Ropeta, 24 Mind Games EDITORIAL BOARD Saturnino G. Belen Jr. President Silvano C. Santiago Illustrator Lourdes F. Lozano Vice Presidents R R R BATO BALANIO for Science and Technology is published bimonthly by Diwa Scholastic Press, Inc. Bato Balani is one of Diwa’s Scholastic Enhancement Materials (SEMO). The SEMO trademark refers to a new genre of scholastic publication, including a selection of premium-quality magazines. Copyright 2000. Articles in this publication may be reprinted provided due acknowledgment is given. All communications should be addressed to THE EDITOR, G/F Star Centrum, Gil Puyat Ave., Makati City, Philippines, Telephone numbers: 843-4761 to 66. 2 SENIOR Have a Toast! Water on Mars T here may be current sources of liquid water at or near the surface of the red planet. This was suggested by the imaging scientists studying the photographs generated from the Mars Global Surveyor spacecraft. The latest images show evidences of presence of water—the size of a car—that are comparable to features left by flash floods on Earth. “The presence of liquid water on Mars has profound implications for the question of life not only in the past, but perhaps even today,” said Dr. Ed Weiler, NASA’s Associate Administrator for Space Science. “If life ever did develop there, and if it survives to the present time, then these landforms would be great places to look.” Finally, that martian lifeforms had indeed existed in the past or could just be in their early stage of evolution can now be considered as not mere conjecture. “Relative to the rest of the martian surface, the gullies appear to be extremely young,” said Dr. Michael Malin, principal investigator for the Mars Orbiter Camera on the Mars Global Surveyor spacecraft at Malin Space Science Systems (MSSS) in San Diego, California. “They could be a few million years old, but we cannot rule out that some of them [water features] are so recent as to have formed yesterday.” Source: http://www.nasa.gov/today Ugly Phenomena Look Oddly Beautiful from Space Hurricanes, typhoons, wildfires, and tsunamis are just some of the natural phenomena that do not leave without causing destruction to lives and properties; a reason why people all over the world view them as ugly spectacles. However, scientists from NASA consider such phenomena as beautiful sights to see. NASA’s Sea-viewing Wide Field-of-view Sensor (SeaWiFS) flying on the OrbView-2 satellite has captured images of two destructive events on Earth. Thick plumes of smoke from forest wildfires in the western United States looked like weaves of cotton. The same day SeaWiFS also captured an image of Typhoon Jelawat, with top steady winds of 115 mph. The typhoon was moving west toward the Ryukyu Islands of Japan when it was photographed. On top view Typhoon Jelawat looked as if the surface of a luscious chocolate marble milkshake. Source: http://www.nasa.gov/today http://www.msss.com SENIOR 3 A Small Dinosaurs recent discovery made by an international team of paleontologists (scientists that deal with the study of fossils of extinct animals, plants, and other living things) again emphasized that dinosaurs were not necessarily gigantic animals that had roamed the Earth millions of years ago. They varied in size from the largest sauropods to the smallest chicken-sized Compsognathus. Digging in Madagascar, the team unearthed fossilized jaws believed to be 230 million years old. They were possibly the oldest dinosaur bones ever found. The latest find have not yet been fully analyzed, but the bones appear to belong to early prosauropods, small herbivores that are most likely the ancestors of the giant Apatosaurus (once called Brontosaurus). John Flynn of Chicago’s Field Museum says these newly discovered dinosaurs were small. They were about the size of a kangaroo and probably walked about on four legs and stood up on two legs to feed. Source: Time magazine Searching for Life in Space S cientists have just discovered a simple sugar molecule, glycoaldehyde, in a giant gas and dust cloud near the center of the Milky Way Galaxy. The discovery was made using the radio telescope of the National Science Foundation on Kitt Peak, Arizona. Sugar molecules are a known chemical precursor to life. They allow certain forms of life to exist entirely without water. Some primitive forms of microorganisms are said to have evolved from strains of sugar molecules. Therefore, the presence of 4 SENIOR the sugar molecule in a cloud from which new stars are forming means it is highly possible that life is formed in such clouds even before planets, including Earth, develop around the Sun. The observations were studied by a group of scientists headed by Jan M. Hollis of the NASA Goddard Space Flight Center in Greenbelt, Maryland. After thorough analysis, the group submitted the results to the Astrophysical Journal Letters. Sources: http://www.nasa.gov/today Nature Biotechnology DR. FRANCISCO O. SANTOS Food and Nutrition Specialist S carcity of food has been a major problem not only in our country but in other developing countries as well. The lack of this basic commodity has brought numerous problems such as malnutrition. Continuous studies and experiments aimed at solving this major problem is being conducted in all parts of the world. Dr. Francisco Santos has devoted his time, talent and energy to food and nutrition research by conducting comprehensive investigations and publishing notable articles both here and abroad. His leading researches dealt with studies on the nutritive values and chemical composition of Filipino food and the amount of vitamins and nutritional contents typical of a Filipino diet. He also formulated a nutrition plan for various families of labor communities in the country, and he investigated on the probable negative effects of a one-sided diet. He has proven that sweet potatoes have nutritional value and anti-beri-beri contents. He also pioneered the promotion of home gardening. Dr. Santos emphasized that this practice is not only a means of livelihood but also the source of essential vitamins and minerals. FALLACY: Too much thinking causes baldness. FACT:“Grass don’t grow on busy streets,” is the common answer of bald men when teased about their shiny heads. Despite the belief that baldness may result from too much thinking, the truth is that bald persons can only blame their ancestors. This condition is hereditary, that is, inherited from our ancestors. Chances are, bald persons have relatives who also have problems with their hair. Baldness may start as early as the teenage period, but it usually begins in the mid-twenties. The average scalp produces some 100,000 hairs, each sprouting from a follicle. The hair follicle is a bulb-like vase which supplies nutrients to the hair. When a strand of hair becomes mature - about shoulder length or longer- its follicle becomes inactive, thus the strand of hair is shed. The average head loses about 100 hairs a day. Some drugs and skin diseases like ringworms may cause excessive hair loss, but hair growth resumes when these problems are cured. Dr. King C. Dulay St. Luke Medical Center SENIOR 5 PHYSICS ARTIFICIAL INTELLIGENCE REDEFINES MACHINES by Raymond A. Oliveros 6 SENIOR A rtificial Intelligence (AI) is the area of computer science focusing on creating machines that can exhibit behavior that humans consider intelligent. The ability to create intelligent machines has intrigued humans since ancient times, and today with the advent of the computer and 50 years of research into AI programming techniques, the dream of smart machines is becoming a reality. Researchers are creating systems which can mimic human thought, understand speech, beat the best human chess player, and countless other feats never before possible. Although the computer provided the technology necessary for AI, it was not until the early 1950’s that the link between human intelligence and machines was really observed. It was Norbert Wiener who theorized that all intelligent behaviors was the result of feedback mechanism. Mechanisms that could possibly be simulated by machines. The most familiar example of feedback theory is the thermostat. It controls the temperature of an environment by gathering the actual temperature of the house, comparing it to the desired temperature, and responding by turning the heat up or down. This discovery influenced much of early development of AI. In late 1955, Newell and Simon developed The Logic Theorist that was considered by many to be the first AI program. The program, representing each problem as a tree model, would attempt to solve it by selecting the branch that would most likely result in the correct conclusion. The impact of the logic theorist on both the public and the field of AI had made it a crucial stepping stone in developing the AI field. In 1956, John McCarthy, who was regarded as the father of AI, organized a conference to draw the talent and expertise of other people interested in machine intelligence for a month of brainstorming. He invited them to Vermont for “The Dartmouth summer research project on artificial intelligence.” From that point on, because of McCarthy, the field was known as Artificial intelligence. Although the field was still undefined, ideas formed at the conference were reexamined, and built upon. AI research centers were established, and new challenges were faced. They placed further research on creating systems that could efficiently solve problems, by limiting the search, such as the Logic Theorist, and systems that could learn. In 1957, the General Problem Solver (GPS) program was developed. It was an extension of Wiener’s feedback principle, and was capable of solving greater extent of common sense problems. While more programs were being produced, McCarthy came up with a major breakthrough in AI history – the LISP (List Processing) language adopted as the language of choice among most AI developers. The following years showed a multitude of programs like SHRDLU that could solve spatial and logic problems; STUDENT that could solve algebra story problems; and SIR that could understand simple English sentences. The result of these programs was a refinement in language comprehension and logic. In the 70’s, the expert system that can predict the probability of a solution under set conditions emerged. Because of the large storage capacity of computers at the time, expert systems had the potential to interpret statistics, and to formulate rules. Another development during this time was the PROLOGUE language. In the quest to create intelligent machines, the field of Artificial Intelligence has split into several different approaches based on the opinions about the most promising methods and theories. These rivaling theories have lead researchers in one of two basic approaches bottom-up and top-down. Bottom-up theorists believe the best way to achieve artificial intelligence is to build electronic replicas of the human brain’s complex network of neurons, while the top-down approach attempts to mimic the brain’s behavior with computer programs. It is the aim of AI researchers who prefer this bottom-up approach to construct electronic circuits that act, as neurons like in the human brain. Although much of the working of the brain remains unknown, the complex network of neurons is what gives humans intelligent characteristics. By itself, a neuron is not intelligent, but when grouped together, neurons are able to pass electrical signals through networks. Warren McCulloch after completing medical school at Yale, along with Walter Pitts a mathematician proposed a hypothesis to explain the fundamentals of how neural networks made the brain works. Based on experiments with neurons, McCulloch and Pitts showed that neurons might be considered devices for processing binary numbers. An important back of mathematic logic, binary numbers (represented as 1’s and 0’s or true and false) were also the basis of the electronic computer. This link is the basis of computer-simulated neural networks, also known as parallel computing. McCulloch and Pitts, using Boole’s principles, SENIOR 7 PHYSICS also wrote a paper on neural network theory. The thesis dealt with how the networks of connected neurons could perform logical operations. It also stated that, one the level of a single neuron, the release or failure to release an impulse was the basis by which the brain makes true / false decisions. Using the idea of feedback theory, they described the loop that existed between the sensebrain-muscles, and likewise concluded that memory could be defined as the signals in a closed loop of neurons. Their contributions were important to AI because they showed how the firing of signals between connected neurons could cause the brains to make decisions. McCulloch and Pitt’s theory is the basis of the artificial neural network theory. Theorists of the top-down approach on the other hand are developing the expert system. This expert system had the potential to interpret statistics, in order to formulate rules. An expert system works much like a detective solves a mystery. Using the information, and logic or rules, an expert system can solve the problem. Moreover, a computer system can be trained quickly, has virtually no operating cost, never forgets what it learns, never calls in sick, retires, or goes on vacation. Beyond those, intelligent computers can consider a large amount of information that may not be considered by humans. People have been studying this issue of AI application for quite some time now and know all the terms and facts. But what they are really trying find out is what can we do to get our hands on some AI today. How can we as individuals use our own technology? According to Adam Dyess, we should be prepared for a change. Our conservative ways stand in the way of progress. “AI is a new step that is very helpful to the society. Machines can do jobs that require detailed instructions followed and mental alertness. AI with its learning capabilities can accomplish those tasks but only if the conservative people are ready to change and allow this to be a possibility. It makes us think about how early man finally accepted the wheel as a good invention, not something taking away from its heritage or tradition,” Dyess said. People must also be prepared to learn about the capabilities of AI. Dyess added, “The more use we get out of the machines the less work is required by us. In turn less injuries and stress to human beings. Human beings are a species that learn by trying, and we must be prepared to give AI a chance seeing AI as a blessing, not an inhibition.” 8 SENIOR Dyess also warns that we need to be prepared for the worst of AI. “Something as revolutionary as AI is sure to have many kinks to work out. There is always that fear that if AI is learning based, will machines learn that being rich and successful is a good thing, then wage war against economic powers and famous people? There are so many things that can go wrong with a new system so we must be as prepared as we can be for this new technology.” However, even though the fear of the machines are there, their capabilities are infinite. Whatever we teach AI, they will suggest in the future if a positive outcome arrives from it. AI is like children that need to be taught to be kind, well mannered, and intelligent. If they are to make important decisions, they should be wise. We as citizens need to make sure AI programmers are keeping things on the level. We should be sure they are doing the job correctly, so that no future accidents occur. 1. What is the significance of John McCarthy being the father of Artificial Intelligence? 2. How is AI being applied nowadays? feedback - the transfer of part of the output back to the input, as of electricity or of information References: 1. Artificial Intelligence Will Evolve by Mick Dobra 2. Artificial Intelligence Web Site by Tim Dunn, Adam Dyess and Bill Snitzer Microsoft Encarta Encyclopedia 99 Why do we sneeze when we look at the sun? Sender: Joana V. Habal Colegio de Sta. Isabel Naga City A sneeze is usually brought about by an irritant in the nasal passages. The irritant may be dust, pepper, mucus, or any kind of pollen to which a person may be allergic. The body reacts involuntarily, by forcing air from the nose and mouth, to get rid of whatever is causing this discomfort. When we look up at the sun, a high intensity of light reaches our eyes. This light causes a high-frequency electrical signal to run through the optical nerves. Some of this electrical impulse is picked up by the nasal nerves located nearby. The nasal nerves send a signal to the brain. The brain triggers the same response as it would when the nasal cavity is irritated. The result: aaaaachooo!!! TAHO Making Soybean is a good source of protein, fats and oil. The famous “taho,” introduced to us by Chinese traders in the early times, makes use of soybeans as its basic ingredient. Here are the ingredients and the simple steps in making taho. INGREDIENTS 3 cups of fresh soybeans 6 cups of water for grinding 7 cups of water for boiling 2 bars of white gulaman 3 cups of dissolved brown sugar cheese cloth pot for boiling stove ladle PROCEDURE 1.Wash and soak the soybeans in water for five to seven hours. The water should be free from impurities to prevent the taho from curdling. 2. After soaking, drain and peel the beans. 3. Using a cornmill grinder or an osterizer, grind the soybeans finely while gradually adding six cups of water. 4. Add the two bars of white gulaman to seven cups of boiling water. Stir until dissolved. 5. Pour the grounded soybeans. Boil for several minutes until the bean-like flavor is removed. 6. Separate the soya milk by straining the mixture using the cheese cloth. 7. Set aside the soya milk and allow the curd to form. 8. To make the syrup for the taho, dissolve brown sugar in a small amount of water and bring this to a boil. 9. Stir the mixture constantly until thick. SENIOR 9 Making a Guessing Game Program by Wacky Salazar In this issue we will focus on some simple sample programs that utilize the techniques we have learned in the past issues. REM HERE IS A SCORED GUESSING GAME PROGRAM CLS RANDOMIZE TIMER TOP: X = INT(RND * 20) + 1 MAX = 3 GAME = GAME + 1 PRINT PRINT “GAME #”; GAME DO UNTIL MAX = 0 OR N = X PRINT “You have”; MAX; “tries to guess my number” PRINT “My number is between 1 and 20” INPUT “What is your guess”; N IF N <> X THEN MAX = MAX - 1 IF N < X THEN PRINT “HIGHER” ELSE PRINT “LOWER” END IF END IF LOOP IF MAX = 3 THEN 10 SENIOR SCORE = SCORE + 10 ELSEIF MAX = 2 THEN SCORE = SCORE + 5 ELSEIF MAX = 1 THEN SCORE = SCORE + 2 ELSE GOTO FIN END IF PRINT “Your current score is:”; SCORE GOTO TOP FIN: PRINT “Sorry Game Over!!! Your score is:”; SCORE OPEN “scores.dat” FOR INPUT AS #1 INPUT #1, top CLOSE IF TOP < SCORE THEN PRINT “You have a new high score!!!” PLAY “c6f6” OPEN “scores.dat” FOR OUTPUT AS #1 PRINT #1, SCORE CLOSE ENDIF END Please note that you have to make a file called scores.dat for this program to work. You can do this with the following steps: STEP 1: At the command prompt go to the directory where your file is located STEP 2: Create a file by typing COPY CON SCORES.DAT STEP 3: Enter 1 STEP 4: PRESS CONTROL – Z By now you should have the tools to create other programs on your own. There are several sites on the internet which can help you learn more about programming in QBASIC. The language may seems simple but that’s what makes it very powerful. If you have the time visit sites like WWW.QBASIC.COM and see the potential of programming with QBASIC. Well Let’s leave you with one last program to think about and have fun with. This program has no end so why not complete it. MX = 5 MY = 12 E1X = 70 E1Y = 1 E2X = 70 E2Y = 23 CLS PRINT “The object of the game is to move around the screen without getting caught” PRINT “U - you” PRINT “@ - Enemies” INPUT “PRESS ENTER TO CONTINUE”, xyz$ CLS DO WHILE DONE = 0 MV$ = INKEY$ LOCATE MY, MX PRINT “ “ SELECT CASE MV$ CASE “I”: IF MY > 1 THEN MY = MY - 1 ELSE MY = 1 CASE “M”: IF MY < 23 THEN MY = MY + 1 ELSE MY = 23 CASE “K”: IF MX < 80 THEN MX = MX + 1 ELSE MX = 80 CASE “J”: IF MX > 1 THEN MX = MX - 1 ELSE MX = 1 END SELECT LOCATE MY, MX PRINT “U” LOCATE E1Y, E1X PRINT “ “ C1 = C1 + 1 IF C1 = 700 THEN GOSUB CHASE1 LOCATE E1Y, E1X PRINT “@” LOCATE E2Y, E2X PRINT “ “ C2 = C2 + 1 IF C2 = 500 THEN GOSUB CHASE2 LOCATE E2Y, E2X PRINT “@” LOOP CHASE1: IF MX > E1X THEN E1X = E1X + 1 IF MX < E1X THEN E1X = E1X - 1 IF MY > E1Y THEN E1Y = E1Y + 1 IF MY < E1Y THEN E1Y = E1Y - 1 C1 = 0 RETURN CHASE2: IF MX > E2X THEN E2X = E2X + 1 IF MX < E2X THEN E2X = E2X - 1 IF MY > E2Y THEN E2Y = E2Y + 1 IF MY < E2Y THEN E2Y = E2Y - 1 C2 = 0 RETURN SENIOR 11 by Alfie Vera Mella Have you met Robocop? “Robo who?” Robocop. That police officer who after being pronounced dead was revived into a half-human, half machine marvel of law enforcer. “Really?” Hey, have you not seen the movie? “Yeah, yeah. Now I remember. It was in 1987 when the movie Robocop was shown in theatres. Set in Detroit, Michigan, USA, the story was about police officers that were required to sign a waiver as they join the force. The waiver gave OCP, the employer of the police force, control over the lives of the officers. But little did they know that OCP also had control over their bodies. So when Alex Murphy, an officer, was wounded in the line of duty and pronounced dead, he was transformed into a half-human, half machine perfect cop called Robocop. The plan was to create a 24-hour serving cop. While sitting in a specialized chair, technicians “remade” Murphy into a cyborg. Equipped with a gridlike targeting system that was his vision, Robocop shot with accuracy. He also had perfect audio recording and playback capabilities. Ultimately Robocop served as the perfect cop. “Wow! Amazing.” Unfortunately, Robocop is just a fiction of the mind, just intended for the movie. Actually humans have dreamed of having a 12 SENIOR perfect assistant worker for centuries. Someone or something that can do an enormous amount of work without getting tired and worn out. This was the primary reason why robots came into being. The term “robot,” which was derived from the Czech word robota meaning “forced labor,” was first introduced in 1920 in a play written by a Czechoslovakian science fiction author. Since then, or even before that, many attempts to invent an ultimate robot proliferated both in movies and in real life. Movies like Phantom Empire (1935), Target Earth (1954), and the most popular Star Wars (1977) are just some of those that introduced robots as being able to act and operate in the same manner humans can. However, these robots, like C-3PO and R2D2 from Star Wars and our cop hero Robocop, are not real. They are just characters in film. In real life though, scientists have already gone a long way in inventing robots. A robot is an automatically operated machine. It is a computer that simulates a human brain. It can be taught or programmed to perform human tasks efficiently. And if you think robots are mainly amazing characters of sci-fi movies, you are wrong. Presently robots in varied forms and for various purposes are all over the world. From robots that paint cars at Ford plants to driving trains in Paris, France to defusing bombs in Northern Ireland, the once imaginary creations are really helping humans in many ways. However, robots are now also invading homes, as pets! Yes, it is a common trend nowadays not only among children but adult alike. If we have Robocop in the silver screen, we can have a robodog there in our homes—which is just among the list of today’s cyberpets. Among the robodogs two are competing for popularity—Sony Entertainment’s Aibo ERS-111 and Tiger Electronics’ Poo-chi. The technological features of these two robodogs are basically the same, however, Aibo is a little more “trained” than Poo-chi. Aibo ERS-111, according to its makers, is an autonomous robot that acts in response to external stimulation. It has a 64-bit RISC processor and its own operating system. It also has 16 MB of RAM, a 180,000pixel-CDC color camera, stereo microphones, heat and touch sensors, 18 joints, and perfect pitch. Poo-chi, on the other hand, knows six songs, has flapping ears, can sit, stand, or dance, and projects wide, expressive eyes. With these new entries in the world of robots, it is quite sure that robots, which once were just confined to too technical tasks, can already be enjoyed as “pets” by anyone who would care to have a new best friend. “Arrf, arrf!” Oops, here barks my robodog. 1.How are robots important to humankind? 2.What are the main features of Aibo and Poo-chi? 3.Cite examples of robots in film. cyborg - cybernetic organism; electric computer that can simulate the human nervous system References: 1.http://www.movieprop.com/tvandmovie/robocop 2.Robots. Shabnam Gupta. 1993 Learners Press. SENIOR 13 Global Cooling: Into Another Ice Age? by Ernesto Buensuceso Ferreras Jr. W hen you park your car outside in the sun, the car soon gets warm inside. Visible light from the sun penetrates the car windows and the interior of the car gets hot by absorbing and converting the light into heat or infrared radiation. In effect, the interior of the car becomes a greenhouse. Glass is opaque to infrared, and heat does not escape. In a similar process, the Earth with its atmosphere is like a giant greenhouse. The atmosphere is nearly transparent to short wave and visible solar radiation from the sun. Part of the energy absorbed by the Earth is radiated to the atmosphere as long wave infrared radiation. And the atmosphere, like glass, prevents heat from escaping, thus warming the Earth’s surface. The Natural Greenhouse Effect About 40 percent of the energy coming from the sun reaches the Earth’s surface. Of this, the Earth’s surface reflects about 15 percent of the solar radiation back toward space. The remaining energy heats the surface, which then sends most of the heat back into the atmosphere, mostly as infrared rays and water vapor. When the rays from the lands and seas are reflected back into the atmosphere, greenhouse gases and particles absorb the rays. As a result, the gases and particles are heated. Some of the infrared rays from the gases and particles radiate back toward the Earth’s surface and contribute to the warming of the surface layer of air. This is known as the natural greenhouse effect, which keeps the Earth’s surface warm with an average temperature of about 15 degrees Celsius. Without this natural process, the average surface temperature would be 33 degrees Celsius colder than it is now. 14 SENIOR The chief greenhouse gases are water vapor, carbon dioxide, methane, and ozone. The greenhouse particles include cloud droplets, soot, and dust. Global Warming Today, there is a global clamor against the continued pumping of human-made greenhouse gases into the atmosphere. It has been estimated that since the 1800’s, when modern industry became widespread, the average temperature of the Earth’s surface has increased by 0.3 to 0.8 degree Celsius. And by 2100, the Earth’s surface temperature is expected to rise between 1.5 and 4.5 degrees Celsius. Many experts believe that the rise in the average global temperature is brought about by the increase of greenhouse gases in the atmosphere, such as carbon dioxide and methane. For instance, measurements revealed that the amount of carbon dioxide in the atmosphere has risen by about 25 percent and that of methane by 150 percent. Human activities, like burning of fossil fuels and clearing of forests through kaingin system, have been pointed out as the main culprit in the increase of greenhouse gases. This increase in surface temperature is called global warming and its effects could alter the face of the Earth. For example, people could begin to farm in regions where it is currently too cold. The change could also affect the survival of many species. A great number of species are already struggling to survive due to destruction of their habitats. Global warming could further push them to extinction. Global warming could also alter rainfall patterns, melt enough polar icebergs to raise the sea level, and intensify tropical storms. Global Cooling It seems obvious then that by increasing greenhouse gases and particles, the Earth will become hotter. However, according to some scientists, global warming might plunge us into the opposite condition, that is, an ice age. How is this possible? The main player is the Gulf Stream, the ocean current that brings warm surface water northwards Europe from the Caribbean. Normally, as the Gulf Stream flows, some of its water evaporates. The rest becomes saltier and thus denser. Eventually the dense surface water sinks to the bottom, where it flows back southward. (The water returning south is called the Canaries current.) Near the equator, the returning water is diluted once again by warm, fresh water from tropical rivers and rain, allowing the water to rise to the surface. The water warms up and the cycle begins again. Moreover, global warming can wreak havoc on the Polar Regions by melting the icebergs. Melted ice from the Arctic will supply fresh water into the North Atlantic. Added to this, it is predicted that global warming can also increase the amount of rainfall in northern latitudes. The result is that the Gulf Stream’s water will be diluted and thus become less dense. It will not sink so easily to the sea bottom. The Gulf Stream’s underwater current, without this renewing supply, will stop flowing south. This in effect will shut off the great ocean current. If that happens, the European continent will get very cold. More snow will fall, and snow will reflect more of the sun’s energy back into space. That will make the temperature even lower. Furthermore, the Gulf Stream will change the global ocean current patterns because it is tied into them. The effect of this is less overall evaporation. The loss of water vapor, an important greenhouse gas, will mean even more dramatic cooling — a decrease of perhaps as much as 8 degrees Celsius. Worst of all, experts believe such changes could come on quickly — perhaps within a decade or less. There’s no need to say then that an ice age by the middle of the century would gravely endanger most of life on Earth — a sort of biological apocalypse. The Search for Solutions Because global warming might do much harm, many scientists recommend a reduction in the emission of greenhouse gases. Popular ways adopted to curb the greenhouse effect include the planting of trees to absorb carbon dioxide, the development of more fuelefficient cars, and the installation of electricity-generating solar panels, among others. More controversial strategies have been considered. For example, governments could promulgate laws that specify the type of technologies to be used or the amount of fossil fuels to be burned. Governments may also levy taxes on emission of greenhouse gases. Another option is to limit the amount of greenhouse gases that would be emitted by every country. Each nation would be issued “emissions permits” that could be bought and sold. Richer nations could purchase permits from poorer nations. More developed countries would have incentives to use more efficient technologies, and less developed countries would receive money to aid their development. At the moment, though, the dangerous plumes of heat-trapping gases are still increasing in volume. Earth is predicted to warm by 0.5 to 1.6 degrees Celsius due to past greenhouse gas emissions. However, beyond that, additional warming could be lessened if not prevented. The choice is ours to make. 1. 2. 3. In what way may global warming usher in another ice age? Explain briefly how the Gulf Stream warms the European continent. What should be done to reduce emissions of greenhouse gases? greenhouse effect - the trapping of the sun’s warmth in the lower atmosphere caused by high levels of carbon dioxide and other gases more transparent to incoming solar radiation than to reflected infrared radiation opaque – blocking the passage of radiant energy and especially light short wave – electromagnetic radiation having a wavelength equal to or less than that of visible light long wave - electromagnetic radiation having a wavelength greater than that of visible light solar radiation – radiation produced by the sun kaingin - process of clearing the forest through burning References: 1. 2. 3. Wilbraham, Antony C. et al. 1997. Chemistry, 4 th Edition. California: Addison-Wesley Publishing Co. World Book Millennium 2000 Encyclopedia. 1999 Chicago: World Book, Inc. Lemonick, Michael D. “…And Then How Cold.” Time, November 8, 1999. SENIOR 15 I N C O O P E R AT I O N W I T H T H E DEPARTMENT OF SCIENCE AND TECHNOLOGY PRODUCTION OF CARBON PAPER USING CHARCOAL AND BLACK MIX OF USED BATTERY AS PIGMENT ABSTRACT as the medium. The pigment (carbon black) to vehicle The objective of the (glycerol) ratio of 1 g : 6 mL and 1 g : 7 mL was used first part of the study was using carbon black as pigment with glycerol as vehicle. to find the best ratio of ink Although the commercial bond paper has better quality, using carbon from used since it uses more technologically advanced methods, batteries and charcoal as the use of the experimental carbon paper was pigments. The ink was acceptable. evaluated on the basis of INTRODUCTION how much pigment is Carbon paper has many uses. It has a high suspended in the mixture and demand in schools, offices and other institutions. The their shelf life. ink used in the production of commercial carbon paper The second part was is expensive due to its high production costs. Because aimed at the production of of its high cost and increasing demand, there arises a carbon paper. The best kinds need for a cheaper substitute. The study also aims of ink were tested on two to help reduce the problems in disposing mediums, coupon bond and onion skin. They were also used batteries making good use tested for efficiency in terms of the number of coatings of them. needed. The carbon paper was evaluated on the basis of clarity, neatness of the print and general acceptability. The final sample made use of two coatings of the ink mixture using carbon black, with coupon bond 16 SENIOR REVIEW OF RELATED LITERATURE In order for the pigment to thoroughly dissolve Ink is a mixture of vehicle (liquid component with the vehicle, the pigment must be pulverized to very and solvent), pigment (coloring matter) and other fine particles. The pigment affects the properties of substances added to impart special qualities such as a ink such as gloss and opacity. The vehicle on the other binder. Carbon is usually used as pigment because of hand must suit the following conditions: (1) the printing its low oil absorption, ease of dispersion and low system used; (2) class and speed; (3) drying press abrasion to plate ware. Carbon is chemically inert and required; (4) class and texture of the surface to be infusible at atmospheric pressure, which makes it an printed; and(5) nature of pigment. Glycerol is viscous essential part in the black pigment used in books, and is easily absorbed by paper and, thus, makes it a magazines, newspapers, carbon paper, etc. Two good good vehicle. sources of pigments that are carbonaceous in nature Burned wood is a good source of charcoal. are charcoal and the black mix found in used batteries. Batteries have black particles called black mix, which These sources are much cheaper than the usual black is primarily composed of carbon black, acetylene black pigments such as carbon black in graphite and and manganese dioxide. The carbons obtained from lampblack. both sources are carbonaceous in nature, making them good sources of black pigment. Coconut oil and dextrin were tested for their potential as ink binders. According to the results, coconut oil was a better binder than dextrin. METHODOLOGY Black mix was obtained by opening the protective housing of a drycell battery and exposing its carbon content. Then, the black mix was removed and ground into very fine particles using a mortar and pestle. Afterwards, it was sieved through a fine screen to obtain the finest consistency. On the other hand, charcoal was also finely pulverized. It was then mixed with water and placed in a one-litre beaker. The mixture was allowed to settle for two days inside the covered by beaker. After two SENIOR 17 days, the charcoal pigments were heated to allow torn even after one coating. The coupon bond was evaporation of excess moisture. proven to be the better alternative. It takes five (5) In preparing the ink, the charcoal and carbon minutes for a solution with a ratio of 1 gram (pigment): black pigments were combined with glycerol (vehicle) 6 mL (vehicle) to dry up. The solution with a ratio of and coconut oil (binder) in different proportions ranging 1g : 7 mL took six (6 ) minutes to dry. The sample from 1 g : 10 mL : 1 mL (pigment : vehicle : binder which used two coatings was ratio) to 2 g : 14 mL : 2 mL. The solution was thoroughly proven to be most practical. mixed using a stirring rod until totally dispersed. Finally, SUMMARY AND the mixture was heated for five (5) minutes under CONCLUSION medium heat and was allowed to cool down The before evaluation. experimental carbon paper is acceptable The best ratio using each pigment was then compared enough to be used as a substitute for commercial carbon paper. The experiment to determine which ink was able to prove that the pigment obtained is more suitable for from battery carbon is better and cheaper than those carbon paper production. from charcoal. The samples were evaluated for smoothness, consistency, and absorption. The ink samples, ranging from one to four coatings, were applied on the onion skin and coupon bond. Researchers: Jonas Don Castelo Lloyd Gonzales Marcelino Quito, Jr. The different carbon papers were tested and observed for their drying time, firmness and clarity of print. After determining the best sample, a survey was Miss Juanita Cruz Research Adviser Note: conducted on 20 students using the experimental carbon paper and a commercial carbon paper. RESULTS AND DISCUSSION The onion paper appeared to be too thin to be used as a medium because it has the tendency to be 18 SENIOR No part of this article may be used or reproduced in any form whatsoever without written permission from the Philippine Science High School, Diliman, Quezon City, except in the case of brief citation as embodied in the laws of scientific articles and reviews. Literally means “false science.” Therefore, it is best for the public to be made aware of the facts behind pseudosciences – practices and beliefs that have no reliable scientific bases. These include false beliefs that are, almost always, results of the ignorance and gullibility of the oldfolk, who tend to rely strongly on “coincidence mentality.” However, more baffling is to know that despite the advancement of science – the foundation of human knowledge – many continue to patronize pseudosciences. This section aims to expose these pseudosciences, which do not only hamper progress, but may also pose harm to the health and sound judgment of those who get influenced by them. But worry not, just a dose of true science cures the most ignorant of minds. J Backmasking ust a few years ago, some local alternative bands, the likes of Eraserheads, Yano, the Youth, and Rivermaya, caused quite a stir when some groups alleged that their songs contained subliminal demonic messages. The accusers delved on the issue of backmasking. Backmasking is the process of playing a piece of music on compact disc, vinyl, or cassette tape in reverse. This process, according to moralists, reveals demonic and other blasphemous messages. They say that such messages are put there either intentionally or subconsciously by rock bands, especially by whoever composed the particular song. The issue of backmasking was already hyped in the past. The same accusation hurled on our local alternative bands was already slapped onto the faces of famous rock bands of the 70’s. Seventies’ rock bands like Led Zeppelin, The Eagles, and Black Sabbath were also accused of putting demonic messages into their songs. The accusation was, of course, vehemently denied by the bands. It was not proven. The same accusation lodged on our very own local alternative bands has not been proven as well. Why? For the simple reason that the idea of backmasking is not true at all. Music experts and sound engineers say that the message being deciphered through playing the music in reverse is only accidental. They even defended rock bands by saying that any piece of music, rock songs or not, will most likely “reveal” unsavory messages when backmasked. Rock songs are the favorite victim of such propesterous allegation. The sole reason is that rock music and other forms of alternative music has long been associated with sex, drugs, and fast life. However, time and liberal thinking proved that such assumption is baseless and unfair. Rock music analysts say the ideas of backmasking is just an attemp by several “conservativists” to discredit rock music. Rock music, like folk, classical and other types of music, is already regarded as a musical artform. Thus, subliminal messages believed to be revealed through backmasking are just a fiction of the mind of fault finding moralists who hate rock music. Being a musician myself, as the vocalist of a local new wave band named halflifehalfdeath, I have also done thorough study about backmasking. According to my findings, the supposed “demonic message” deciphered through backmasking is just the lyrics of the song read in reverse, from beginning to end. Following this logic, any piece of music, poetry, or a mere spoken sentence when recorded then played in reverse will definitely sound weird. And in some instance, just like what happens to a rock song when played in reverse, might hit a blasphemous word or two. by Alfie Vera Mella song for our new album. Let’s say the song is about a plea to the government to lower the cost of consumer products. The song would probably have a line which goes like: Huwag na sana taasan pa ang presyo ng mga bilihin. For example, we were able to record the song and produce it commercially. Since our musical style generally falls under the category of rock, some “moralists” might accuse us of putting demonic messages in our songs. They would probably backmask our songs. Say they have chosen the new song we recorded. Most likely they will find what they are looking for. Why? Okay, let us read the following line in reverse (from end to beginning): Huwag na sana taasan pa ang presyo ng mga bilihin You would have read it as: NIHILIB ANGAM NGAN OYSERP NGA AP NASAAT ANAS AN GAWUH Fault finders would probably hear this as: NILILIBANG ANG AY SARAP NGA NA SATANAS ANG GAWIN. See? This is just one sentence. What more if the entire lyrics of the song is read in reverse? Let us have an example: Suppose I will compose a new SENIOR 19 PHYSICS Computer vs. Human Brain by Ernesto Buensuceso Ferreras Jr. C onsider this: The human brain can handle a few thousand instructions per second. The fastest computers can race through a whopping 2 trillion operations per second, or 2 teraflops. Needless to say, computers work faster than our brains. Does this mean that they will ultimately become more intelligent than the human brain? Can they achieve a sense of “I,” the way we perceive ourselves? There are already computers that can “outthink” the most brilliant of human minds. Given the pace of today’s technology, what will it take to make a computer that thinks on its own? To create a machine that simulates the human brain, some scientists speculate that about 20 million billion calculations per second are required. Parallel Processing: Models for Information Processing In almost every aspect of human activity, computers have proven themselves indispensable because of their reliable performance. For instance, computers can diagnose some diseases, manage investment funds, play chess, and do other things that seem impossible to us. Some computers can even learn and their performance improves with experience. The rapid growth of computer technology has spurred scientists to build machines that possess some characteristics of the human brain. Yet, no computer has been able to equal the capacity of the human brain to handle information. The human brain, with its 100 billion neurons and roughly 100 trillion connections, requires a lot of computing power. At best, however, scientists invented a computer, called the Perceptron, that was modeled after the human brain. It has been used to study the principles that underlie natural intelligence. Scientists apply the principles behind the functioning of the brain at the neuron level to computer design. A neuron is a cell that processes information. But the neuron is too small to carry much information. To compensate for this setback, however, neurons function in parallels. This increases the capacity of the nervous system, of which the brain is the informationprocessing center. Computer scientists are applying parallel processing to the design of more advanced machines. Most of today’s computers process information serially, one element at a time. In parallel computers, hundreds of small microchips are structurally linked. The computers break tasks into their smallest units and assign each unit to a separate processor. Thus, the problem can be solved much more quickly with many processors simultaneously working on a given task. One parallel computer design called the Thinking Machine uses several thousand inexpensive microprocessors and can outperform many of today’s supercomputers. Computer Software: Artificial Intelligence and Expert Systems The development in computer hardware depends on the efficiency of the software that goes with it. Software programs control the hardware and form the 20 SENIOR interface between the computer and you, as the user. Software is now becoming increasingly user-friendly and intelligent. They are able to adapt to your personal habits. There are a few word-processing programs that can learn your writing style and offer suggestions. In playing games with computers, you will have to concentrate more each time you start a new game because game programs can learn by experience and become difficult opponents. However, for a computer program to convincingly respond, it would have to be as complex as a human brain. It is widely believed that human intelligence has three principal components: consciousness, the ability to classify and retain knowledge, and the ability to make choices based on accumulated memories. Today’s computers possess artificial intelligence or the ability of a computer to imitate human actions or skills. Human skills include problem solving, decision-making, learning, reasoning, and selfimprovement. Computers can duplicate some aspects of intelligence: for example, they can find the most efficient solution to a complex problem, or they can improve their performance with experience, such as with chess-playing computers. However, you, as the programmer, choose the goal, establish the method of operation, supply the raw data, and set the process in motion. Computers are not in themselves intelligent. Evolvable Computers Experts believe that the final step to intelligence is achievable. To achieve this, engineers devise new designs in both hardware and software. One advance design in computer hardware is in a field of research known as evolvable hardware, or evolutionary electronics. In this area, the hardware evolves to solve problems, like the way our own neurons evolved to solve problems and to contemplate ourselves. A type of silicon processor, called Programmable Field Array (FPGA), can change its wiring in a few billionths of a second. You can reconfigure the FPGA chip. You can change the logic elements by reprogramming the bits in the chip’s memory, known as configuration bits. For example, OR gates can be changed to AND gates or NOT gates, input wires can be reprogrammed to be output wires, etc. This gives an FPGA extraordinary flexibility. Since all this manipulation is carried out electronically, the wiring of the processor can evolve for thousands of generations, eventually becoming a circuit that is very efficient at solving the task. It uses the process of evolution to explore new ways of computing. But could computer engineers actually end up with a thinking machine as conscious as you or I? A way to test whether a computer has become intelligent is to perform the Turing Test, named after the Alan Turing, an English scientist. To conduct the test, you ask questions of two entities, which are hidden from you as the human questioner. One entity is a human, and the other is a computer. If you were not able to distinguish which entity is the human and which is the computer, then the computer has proven itself intelligent. A computer usually reflects the mental processes of its human programmer. The human programmer creates the software, which instructs the computer to solve problems or perform its assigned jobs. When a computer is used to solve special problems, the methods of experts are incorporated into its program. Some scientists believe it is unlikely computers will start thinking for themselves. A computer is technically a machine that uses symbols to compute, which is nothing like the way human or animal brains work. Computers operate by manipulating symbols, the 1’s and 0’s of the binary language. To mean something, it is necessary to have causation. In other words, the symbols the computer manipulates would have to mean something to the computer. But instead, they only mean something to the human programmers. The symbols in the computer mean nothing at all to the computer. In this regard, the computer cannot be said to be thinking. A computer that only seems to be thinking and acting like a human is really not conscious. Therefore, in this final regard, building a computer that would eventually replace the human brain in all its guises is still far-fetched. 1. How do neurons in the brain process information? 2. Why do you think a machine can never become as intelligent as the huiman brain? computer logic – the arrangement of circuit elements needed for computation interface – the place at which independent systems meet or communicate with each other microchip – an integrated circuit References: 1. Compton’s Interactive Encyclopedia. 1999. The Learning Company. 2. Discover, June 1998. 3. Popular Science, March 2000. SENIOR 21 PHYSICS Liquid Crystal Technology by Alfie Vera Mella S urely you have already used a cellphone or, at least, have seen one. You might even have one of your own. Text. Text. Text. Turn it on. Enter PIN code. •••• Press OK. Code accepted. Check the view screen. Signal? OK. Battery indicator? Full. Press Menu. Select Messages. OK. Now compose your message on the view screen…helö! batobalani ed. i’v a question? Send. Enter number. 09192170526. OK. Message sending failed. Try again. Message sent. At last! But have you taken a closer look at the view screen of the cellular phone? At that gray substance where all those letters, numbers, symbols, and icons are being displayed? This is what is known as the LCD. The LCD, or liquid-crystal display, is a constantly operating display that consists of segments of a substance known as liquid crystal. And this liquid crystal is the “magic” behind the LCD and other similar materials. In fact, it is almost everywhere: in hospital equipment, in road signs and billboards, and in ad displays. However, before we can truly appreciate its usefulness, we should first learn what kind of a substance the liquid crystal really is. Liquid + crystal. An unlikely pair. A crystal is known to be generally solid and rigid. Liquid is not. Being solid, a crystal has molecules that are arranged in a very orderly way. Its molecules are locked into a rigid structure by electrical forces between the molecules. Liquid molecules, on the other hand, can move around freely. Remember? A liquid has no structure and takes the shape of its container? The usefulness of the liquid crystal is attributed to its molecular arrangement and behavior. In the liquid crystal, molecules behave as a solid and a liquid at the same time. They can move around freely but tend to remain rigid. Thus the liquid crystal is usually thick and flows slowly. However, the liquid crystal is more effective when it is spread out in a 22 SENIOR thin sheet. In this way, there are only a few layers of molecules, which are structured so rigidly that they hardly move at all. The liquid crystal can change very easily in the way it reacts to light. It can be transparent one moment and opaque the next. It may be single-colored now, then multi-colored after a short while. These changes can be brought about by factors such as a rise or fall in temperature, a slight electric current, or a small change in pressure. And by controlling such changes, the liquid crystal can be put to work in so many ways. The most common application of the liquid crystal is in the LCD of cellular phones, calculators, and some watches. How does the liquid crystal work? The liquid crystal is placed between two panes of thin glass. The molecules of the liquid crystal line up in an orderly manner, and light passes through the material without any trouble. Remember, the glass pane is transparent. However, when a small electric current is caused to pass through the liquid crystal, its molecules break apart. Now light is scattered and the glass pane becomes opaque. In the LCD, the electric current is applied only to certain parts of the liquid crystal in between the glass panes. The parts are designed into letters, numbers, etc. When the current passes through them, they become opaque and “spell out,” as in the cellphone, the typed message. The LCD in some road signs, billboards, and ad displays also works this way. Being sensitive to temperature changes, the liquid crystal is also used in some hospital equipment, particularly in temperature-monitoring tools. For example, a disk made of a liquid-crystal material is placed on the patient. The body temperature of the patient affects the color of the disk. Change in the color of the disk, in turn, determines the body temperature of the patient, indicating whether the patient is afebrile or not. In fact, disposable liquid-crystal thermometers based on this technology are already available in the market. Significant advancement in the liquid crystal technology is now seen in appliances such as video games, flat televisions, and computers and in the field of medicine, as coatings placed on the skin to reveal underlying tumors. References: 1. Encyclopedia Americana Intl Ed. 1983 Grolier Incorporated. HOW TO MAKE AN ELECTRO MAGNET By using electricity, you can have your own electromagnet. Unlike any ordinary magnet which remains magnetic at all times, this electromagnet may be switched on and off. MATERIALS: 2 metres of coated wire , 4.5V battery (or 3 pcs. 1.5V batteries), pliers or pocket knife, scissorrs, paperclips or any small metal objects, long screwdriver, adhesive tape 1. Strip both ends of the coated wire and tape part of it to the handle of the screwdriver. 2. Wrap the rest of the wire around the screwdriver. Tape the other end. 3. Connect one end of the wire to one of the battery terminals. Then, connect the other end of the wire to the other terminal 4. The screwdiver is now an electromagnet. Watch as it attracts some paperclips! Detach one of the wires from the battery and the paperclips fall off. SENIOR 23 COMPLETE THE SQUARES WHO’S WHO Identify each robot and tell what movie each appeared in. ACROSS 1 movement of a solvent through a semipermeablemembrane 8 correction (abbreviation) 10 coating or fastening agent 11 the neverending question asked by children 12 map reference 13 extraterrestrial 14 postal letters 16 female egg cells 18 break in skin or mucous membrane 21 Erbium 22 the sun with the nine planets and other heavenly bodies 23 international monetary unit 24 _ _ _ _ _ Ark; carried living creatures of every kind during the Great Flood 26 the body of an organism 28 _ _G; liquefied natural gas 29 indicates a sudden occurrence 31 lighter or darker shades of a color 33 _ _ _ _ _ _ of Langerhans 35 given recognition 37 _ _ _d_; positive terminal of an electrolytic cell 38 a basic principle or a fundamental skill 24 C R O S S W O R D 1 2 3 4 5 6 7 10 12 1 13 16 17 1 18 1 1 19 20 1 1 1 11 8 9 14 15 1 21 22 1 23 1 24 26 27 1 28 32 1 1 31 35 1 36 38 SENIOR 1 33 1 1 1 29 30 25 34 1 37 1 1 DOWN 1 same as 1 across 2 a power-driven mechanism that supplements a primary control 3 master of arts 4 oil (prefix, combination form) 5 sixth planet of the solar system nearest to the sun 6 not out 7 standard time 8 22d letter of the Greek alphabet 9 part of the plant stem that carries nutrients 11 horny projections on the skin 14 the fabric of a net 15 Strontium 17 _ _ _ _ _ _ _m; chemical element Al 19 _y_ _ _; a brand of disinfectant 20 poison usually used in illegal fishing 25 _ _ _ _ dixit; an assertion made but not proved 27 _ _ _ _e; same as 37 across 29 a form of meditation 30 smallest particle of an element 32 three (prefix, combination form) 34 _ _ _ex; synthetic rubber products like surgical gloves are made of 36 electromagnetic