Instead, one can utilize the apparent contradiction to help define other parameters of the Big Bang such as or , the cosmological constant, which acts as an accelerator and has the effect of increasing T for a given H . Before turning to the values of and , we must be confident that the distances to galaxies are measured correctly. Despite 70 years of hard work on the problem, distances remain a controversial subject. Computer Software Can Help Software has been called upon to assist with these inadequacies. Software has become essential for extracting the key scientific variables, usually magnitudes, transforming their systematic errors into random ones, and deriving their uncertainties in an objective fashion.
Astronomers frequently overlook a critical revolution that has occurred in the last decade.
Several software systems are available today at either no cost or low cost within which the average astronomer can reduce and analyze data easily. Ten years ago, each researcher was required to invest heavily in software development to be competitive with one's colleagues. Since the basic precept of the scientific method is that one researcher can reproduce the results of another, and software is a key component in that process, distributable software systems have had a profound impact on the reliability of scientific results. The algorithms, however, are tested far more thoroughly under a wide variety of conditions by astronomers around the world than in the past when only a handful of astronomers used a local, home-grown package. Many distance indicators have been proposed during the 20 century.