Avis Azdagir

Computers and their different applications in Astronomy

Filed under: Astronomy, High Tech — Tags: , — NewLife @ 7:00 pm November 23, 2007

It is common knowledge that the advent of computers has played a major role in different scientific discoveries, particularly in Astronomy. Computers give not only power to astronomy, but also, significantly, make all intricate and complicated calculations feasible. It is true that there are many other discoveries which improve and influence the evolution of astronomy, such as, for example, geometry or the telescope; nevertheless for solving astronomical problems the biggest role is attributed to computers. Since computers with their metamorphoses - minicomputers, network and supercomputers - help astronomy move forward with successful strides. More specifically, however, the development of programming languages, specific softwares have solved most of unsolved problems such as measuring of mass of the Universe or correlations of different astronomical maps for getting a truer picture of the sky.

This research paper will discuss the relationship existing between computers and astronomy, and thereby point to the advantages and disadvantages of this interconnection. Also it aims at analyzing and portraying the effects of the development of computers in Astronomy. Different types of astronomical problems which are solved by means of computers will also be addressed. In addition to this, it is in the interest of this paper to adduce different examples of programming languages and standard softwares which are used in Astronomy. Furthermore, the research is enriched by examples of experiments of professional astronomers emphasizing the indispensable role of computers in this particular field.

In the preceding 5 decades, to begin with, computers had a considerable impact on Astronomy. Many standard softwares and exclusive programs help astronomers to be faster and successful. Astronomers need computers not only for processing information but also for organizing effective observations, recording and archiving of the acquired information by optical telescopes or other Astronomical equipment. Information as well as several types of problems in astronomy changed during their evolution and development. In this respect, information changed from order of several thousands to the degree of thousands; aims of modern Astronomy, in comparison with historical Astronomy, include not only classifying objects or creating maps but also studying galaxy mergers and black hole accretion.

To emphasize the importance of computers in Astronomy, to understand how the preceding generation of astronomers managed to conduct their studies and works without using computers and why present Astronomers can no longer handle astronomical problems without computers, some historical review is given to shed light on the reasons of the said changes.

One of the first works in this area was written by Greek Astronomer Hiparqose (2nd century B.C.) who classified discernable stars into 6 groups. Classification of 6000 stars (3000 in each gap) in 6 groups is possible to be done by one astronomer’s handwork. The same can be said about all astronomical studies before seventeenth century.

By the end of the seventeenth century, everything was changed when Galileo Galilee discovered the telescope. Because people began to study stars not by bare eyes but with some equipments, the quantity of knowing sky objects increased. This discovery opened new horizons and the quantity of information increased in its scope which, in turn, made the composition of new catalogues for astronomers by Bayer and Helios, a little bit difficult.

However, these studies do not par with the observations in the 20th century - when a quantity of knowing sky-objects increased until astronomical quantities as well as questions changed their content from the counting of stars to the measuring of mass of billions objects. This type of problems could be solved only by using computers.

Computers will have a very large role in the future of astronomy as evident from the following approximate calculations. Modern Astronomy recognizes that in the universe the Meta galaxy (boundaries of Universe known at present) contains 50 Extra constellations. Each Extra constellation includes 20000 galaxies, each of which takes in 200 billion stars like our galaxy. (Nersisyan, 2001) This is a number with a shape similar to 2*1017 only for stars, But what about objects with less mass and less volume which are no less important for Astronomers? According to Yan Oort 100 billion comets can be counted only in the Solar system (Nersisyan, 2001), it means that objects which are interesting for scientists in universe can be counted from order of thousands degree of 10. This quantity of information will bring new questions which can not be solved without using computers.

However, before handling future problems, astronomy, at present, also has a lot of problems. There are many projects dedicated to building powerful computers for astronomical needs; there are also examples when power computers developed for other purposes were used by astronomers. For example in the 1950’s John von Neumann used the pioneering computer MANIAC for studying problems of stellar evolution.

Another example is the “the nova supercomputer named McKenzie which has 256 two-processor motherboards that together perform 1.2 trillion floating-point operations per second. McKenzie will tackle some of the most complex problems in astronomy today, like galaxy unions, black hole accumulation, and the production of the cosmic microwave background after the earliest stages of the formation of the universe”. (McNaughton, 2003, p1).

The MANIAC along with the McKenzie project will open large possibilities for scientists. However the one obvious disadvantage is that both projects are of big size and yield limited access for scientists. In particular, these supercomputers can be located only in big buildings and are made in 1 or 2 exemplars. Scientific development, together with its revolutionary discoveries took place in 1980’s the result of which was the establishment of microcomputers. These computers, owing to their comparably small size, are used in all scientific organizations, centers, and offices.

Having an invaluable experience, the National Research Council (international scientific organization) postulates that “Astronomers use computers to collect and study billions of bytes of data every 24 hours and to make theoretical simulations of complex phenomena”. (National Research Council, 1991) As is recorded in their project without computers they could not finish their job. For starting one of the biggest projects in this field National Research Council includes in its plan not only detectors and telescopes but also computers maintaining that: “… the ability of computers to process large amount of data will make possible an improved view of the universe” (National Research Council, 1991).

The importance of microcomputers is shown in many aspects. Because of the small number of supercomputers scientists are deemed to take long lines and face many other inconveniences before they can actually access them. In this sense, one of the advantages of minicomputers, as contrasted with supercomputers, is that they enable all scientists to keep their own archives, carry out their mini elaborations more easily and effectively.

What justifies the foregoing discussion is a project carried out by scientist Suren Khachatryan and his group of associate studying non-liner dynamics of spiral galaxies. According to S. Khachatryan their overriding objective has been the use of non-linear approach instead of the linear. These type of problems cannot be solved by using analytical methods and therefore entail the use of numerical integration which can not be fulfilled without computers (minicomputers). Scientists contend by using programming languages Pascal, C++ and, from standard software, Mathematic, Microsoft Excel to finish their work. (Personal communication, 28 November, 2004).
Communication with their colleagues is not of less importance for scientists, in this sense the advent of network made distant contacts feasible and quick. Network as well as its large manifestation WWW (World Wide Web) enables the scientists to work with each other from different places in the world. This being the smallest benefit of Network in the last decade scientists also have created Virtual Observatory which means scientists have access to the all parts of the sky at all times regardless of their location.

As mentioned above, computers enable scientists to archive the acquired information from observations and elaborations. This is a large opportunity but in this particular field computers do not display their full potential that is the needed size of memory to activate the information derived from one observation reach to terabytes which is unattainable for current minicomputers. Scientists hope that these problems will be solved in the nearest future.

The previous discussion presents some examples illustrating different ways of using computers by astronomers. All this would not take place if there were no software engineers. Modern astronomers deal with software engineering by using many of their methods. One of them, in this regard, is the use of standard softwares; another being the use of specific programs written for each unique situation. However, these two methods contain grave shortcomings.

To begin with, the first method has inadequacy because there are no universal software for all problems. Only some standard softwares are partly universal, for example MIDAS which uses image processes and data reduction with emphasis on astronomical application including imaging and special reduction. In addition, it contains applications packages for stellar and surface photometry and image sharpening. (Software development, n.d.).

Other no less popular and useful software is the IRAF (Image Reduction and Analysis Facility), a general purpose software system for the reduction and analysis of astronomical data. (IRAF info service, n.d.). Moreover, Mathematics, Microsoft Excel and Access are not specifically astronomical programs but are also used for certain astronomic calculations and computations.
The second method is the use of specifically written programs. These programs are realized mostly by the joint work of astronomers and programmers. Astronomers describe the essence of the problem, after which programmers write the specific program. Nevertheless, modern Astronomy problems are becoming increasingly challenging for programmers. The reason is that the evolution of science has brought for them new and more difficult types of elaborations. In some cases programmers do not have the required background in modern astronomy, and consequently this way of solving problems becomes very hard, not useful, and wastes much time. Thus, for creating a better and efficient system which is less time consuming astronomers should learn programming.

To restate the main points considered in this paper, it is conceivable that computers are largely used in modern astronomy. Since many aspects of astronomy succeed because of computers. After the advent of computers, scientific problems are solved faster, archives are safely maintained and observations become more pointed and powerful, because of digitalization. Due to network, the exchange of information vital for scientists becomes faster. Furthermore, computers help to work with huge quantity of objects, elaborate and monitor results. The future of astronomy can scarcely be imagined without computers, that is why many projects are aimed at the development of this relationship.

2004

References:

IRAF info service. (n.d.). Retrieved November 28, 2004, from

http://www.iraf.noao.edu/iraf-homepage.html

McNaughton, R. (2003, March 6). Super computer does astronomy super-fast. The Varsity

Online, 1. Retrieved November 20, 2004, from

http://www.thevarsity.ca/news/2003/03/06/ScienceTechnology/Super.Computer.Does.Astronomy.SuperFast-387339.shtml National Research Council. (1991).The Decade of Discovery in Astronomy and Astrophysics.

Washington, D.C., the USA.

Nersisyan, S., (2001). Astronomy 10. [Astronomy 10]. Yerevan: Tigran Metc.

Software development. (n.d.). Retrieved November 23, 2004, from

http://www.eso.org/projects/esomidas/midas.html

Cultural Influences on Software Project Management

Filed under: High Tech — Tags: — NewLife @ 7:20 pm November 21, 2007

It is time to make relationship between personal and software development lifecycles cultural issues. It is funny, right? But wait, I am sure, after a while we will include in our resumes lines like, “I am Agile Man” or “I am Plan-Driven Oriented” and it will help company to hire people in right place and position. Why? OK, for first let’s group Software development processes into two big meta-methodologies “Agile” and “Plan-Driven” and describe them;

Agile

In an agile culture, the people feel comfortable and are empowered when there are many degrees of freedom available for them to define and work problems. This is the classic craftsman environment, where each person is expected and trusted to do whatever work is necessary for the success of the project. This includes looking for common or unnoticed tasks and completing them. Examples of Agile processes can be;

  • XP
  • Scrum
  • Etc.

Plan-Driven

In a plan-driven culture, the people feel comfortable and empowered when there are clear policies and procedures that define their role in the enterprise. This is more of a production-line environment where each person’s tasks are well defined. The expectation is that they will accomplish the tasks to specification so that their work products will easily integrate into others’ work products with limited knowledge of what others are actually doing. Examples of Agile processes can be;

  • Waterfall
  • Spiral
  • Etc.

Now let’s shift to the common characteristics of these meta-methodologies;

Agile

  1. Effective interactions
  2. Close collaboration
  3. Successful agile teams learn – or strengthen – interpersonal skills
  4. Give congruent feedback.
  5. Navigate conflict.
  6. Think and decide together.
  7. Frequent interaction and face-to-face communication
  8. Members should
  • Create an opening to give feedback
  • Describe the behavior or result without using labels.
  • State the impact (on you, the feedback giver, or on the team).
  • If necessary, make a request.
  1. Teams need three broad skills:
  • Generating ideas.
  • Narrowing the number of options.
  • Reaching agreement.
  1. Agile requires a very effective team of developers
  2. Team needs to be effective both in the quality of the individuals, and in the way the team blends together
  3. The people are the most important factor in software development
  4. Programmers are Responsible Professionals
  5. Individuals and interactions over processes and tools.
  6. Working software over comprehensive documentation.
  7. Customer collaboration over contract negotiation.
  8. Responding to change over following a plan.

Plan-Driven

  1. Focus on repeatability and predictability
  2. Defined, standardized, and incrementally improving processes
  3. Thorough documentation
  4. A defined software system architecture defined up-front
  5. Detailed plans, workflow, roles, responsibilities, and work product descriptions
  6. Process group containing resources for specialists: process monitoring, controlling, and educating
  7. On-going risk management
  8. Focus on verification and validation
  9. Less-capable people can contribute with low risk
  10. Relies heavily on explicit documented knowledge
  11. Communication tends to be one-way.

OK! So, we have flexible Agile vs. stiff Plan-Driven. Not enough? Let’s see more…

Agile

  • Empirical
  • High degree of exploration
  • Leading edge
  • Goals achievable
  • Details unpredictable
  • Macromanagers
  • Process to people
  • Individual skills

Plan Driven

  • Defined process
  • High degree of predictability
  • Tasks defined in detail
  • Accurate measurements
  • Micromanager
  • People to process

According to one very important person, Geert Hofstede, culture of company or group of people can be described with following values;

  • Power Distance
  • Individualism
  • Masculinity
  • Uncertainty Avoidance
  • Long-term Orientation

Let’s take 3 of them (1st, 2nd and 4th) and match with previously listed characteristics of Agile and Plan-Driven. Now let’s draw diagram and call as a “Cultural Diagram of Meta-Methodologies”.

Cultural Diagram

Now I am going to refresh my memory, what for I am doing this crazy comparisons? Oh, yes; according to this diagram e.g. individual with high sense of individualism will be at least uncomfortable in Plan-Driven project and vice versa. Make sense?