Carl Sagan : Astronomy's Greatest Promoter!!

This is an article about the memories of Carl Sagan, Astronomy's greatest promoter written by Dave Eicher, after Sagan's death! It is truly touching and it is my humble request to everyone that they read this article. A Legend who helped us to visualize the universe differently.
 

Carl Sagan, (1934 - 1996)

The Universe lost one of its best friends a few days before Christmas 1996.

Carl Edward Sagan died of pneumonia on December 20 at the Fred Hutchinson Cancer Research Center in Seattle, after a two-year battle with bone marrow disease. The death came as a shock to some who treasured his friendship, as only several weeks before he seemed to be improving and, in his words, "operating at about 80%." The disease that plagued him was myelodysplasia, a form of anemia. Sagan had undergone a bone marrow transplant to counteract the disease at the Hutchinson Center in April 1995.

Sagan will be remembered as a giant in astronomy for his long record of professional accomplishments, his superb writing, and his outstanding ability to communicate complex ideas in simple ways. Despite an extraordinarily busy schedule, he took time to do and say kind and helpful things. He inspired many young astronomers and most of the editors working on the staff of this magazine. Sagan was brilliant. At a conference on comets and the origins of life, he was likely to rattle off details of bonds in organic molecules or launch into a discussion of politics and NASA funding. He seemed actually to know it all -- and the details of it all. But he could tell you with an inclusive smile that made you feel like an insider.

Sagan was born in New York City on November 9, 1934. At the time of his death he was David Duncan Professor of Astronomy and Space Sciences and director of the Laboratory for Planetary Studies at Cornell University in Ithaca, New York, where he had been since 1968. 

He played a leading role in the American space program since its inception. Sagan was a consultant and adviser to NASA since the early 1950s, briefed the Apollo astronauts before their flights to the Moon, and was an experimenter on the Mariner, Viking, Voyager, and Galileo missions to the planets. He helped solve the mysteries of the high temperature of Venus (answer: a massive greenhouse effect), the seasonal changes on Mars (windblown dust), and the reddish haze of Titan (complex organic molecules).

For his work, Sagan received numerous awards, including the NASA Medals for Exceptional Scientific Achievement and (twice) for Distinguished Public Service, as well as the NASA Apollo Achievement Award and the Public Welfare Medal, the highest award of the National Academy of Sciences.
The scientific community didn't always embrace Sagan's tireless efforts with science

popularization. Yet he accomplished more to interest the public in astronomy and space exploration than anyone else of his time, and for that, all who admire science should be eternally grateful to Sagan.

All of us at ASTRONOMY will feel the loss especially deeply. Sagan had served as an advisor to us on occasion and had agreed to take a leading role on the magazine's new editorial board.

The universe shines a little more dimly now.

Dave Eicher.

CALCULUS : A New Horizon from Ancient Roots!!

Calculus, sometimes called the "mathematics of change", is a branch of mathematics concerned with describing the precise way in which changes in one variable relate to changes in other. In almost every human activity we encounter two types of variables : those that we can control directly and those that we cannot. Fortunately, those variables that we cannot control directly often respond in some way to those that we can. For example, the acceleration of a car responds to the way in which we control the flow of gasoline to the engine, and the level of an antibiotic in a person's bloodstream responds to the dosage and timing of a doctor's prescription. By understanding quantitatively how the variable we cannot control directly respond to those that we can, we can hope to make predictions about the behavior of our environment and gain some mastery over it. Calculus, founded by Newton and Leibniz, is one of the  fundamental mathematical tools used for this purpose.

                Isaac Newton                                             Gottfried Leibniz

Calculus has enormous, but often unnoticed, impact on our daily lives. Here are a few areas of research where calculus is used extensively. All of these applications involve other branches of science and mathematics, but they all use calculus in some essential way.

FBI FINGERPRINT COMPRESSION

The U.S. Federal Bureau of Investigation began collecting fingerprints and handprints in 1924 and now has 30 million such prints in its files, all of which are being digitized for storage on computer. It take about 0.6 megabyte of storage space to record a fingerprint and 6 megabytes to record a pair of handprints, so that digitizing the current FBI archive would result in about 200 x 10^12 bytes of data to be stored, which is the capacity of roughly 138 million floppy disks. All this would cost roughly 200 million dollars. To reduce the cost, FBI's began working with several other Institutes and groups to devise compression methods for reducing the storage space. These methods, which are based on wavelets, are proving to be highly successful. Thus, calculus paved the way!!

MUSIC
Researchers at Yale University have investigated the application of wavelets to sound synthesis (music and voice). To approximate the sound of a musical instrument or voice, samples are taken and decomposed mathematically into numbers called wavelet packet coefficients. These coefficients can be stored on a computer and later sound can be reconstructed (synthesized) from the computer data. This area of research makes it possible to reproduce complex sounds from a small amount of data and to transmit those data electronically in a highly compressed form. This research may eventually speed up the transmission of sound over the Internet.

WEATHER PREDICTION
Modern meteorology is a marriage between mathematics and physics. Today's meteorologists are concerned with much more than predicting daily weather changes--their research delves into such areas as global warming, holes in the ozone layer and weather patterns on other planets. In 1904 the Norwegian meteorologist Vilhelm Bjerknes proposed that the state of the atmosphere at any future time can be determined by measuring appropriate variables at a single instant of time and then solving certain hydrodynamic equations. Although, it is difficult to apply this principle. However, new mathematical discoveries have dramatically improved meteorological predictions and spawned enormous
economic benefits.

MEDICAL IMAGING & DNA STRUCTURE
Advances in nuclear magnetic resonance (NMR) have made it possible to determine the structure of biological macromolecules, study DNA replication, and determine how proteins act as enzymes and antibodies. Related advances in Magnetic Resonance Imaging (MRI) have made it possible to view internal human tissue without invasive surgery and to provide real-time images during surgical procedures. High-quality NMR and MRI would not be possible without mathematical discoveries that have occurred within the last decade.

CONTROLLING CHAOTIC BEHAVIOR OF HUMAN-HEART
Chaos theory, which is one of the most exciting new branches of mathematics, is concerned with identifying regularities in phenomena that on the surface seem random and unpredictable. Today's research literature abounds with applications of chaos theory to almost every imaginable branch of science. Researchers at Georgia Tech University collaborated with physicist at the Emory University Medical Center in applying chaos theory to control the chaotic behaviour of heart tissue that is undergoing ventricular fibrillation (cardiac arrest). The research, though experimental, is already showing promising result.

DEEP SPACE EXPLORATION
Alexander Wolszczan of Penn State University may go down in history as the first scientist to identify a planetary system beyond our own. While searching the radio sky, he discovered a new pulsar, PSR1257+12, that seemed to wobble as it travelled through space. As a result of an extensive mathematical analysis, many scientists are now convinced that the wobble is caused by two or three planets orbiting the pulsar. Although scientists have been able to detect pulsars for some time by searching for faint periodic radio signals from outer space, it is only recently that the mathematical techniques have been developed to analyse the data in a way that stands up to scientific scrutiny.

Finally, we can see that today's life has an exciting applications of calculus but, it has roots that can be traced to the work of the Greek mathematician Archimedes, but the actual discovery of the fundamental principles of calculus was made independently by Isaac Newton (English) and Gottfried Leibniz (German) in the late seventeenth century.

Calculus drives our lives today, and further advances will help us achieve even greater heights!!