Knowledge is constantly changing and what was regarded as knowledge yesterday may be discarded today. Arbesman argues that meat was a recommended delicacy before, then it was prohibited by doctors, and today it is a matter of opinion. To understand the phrase that the knowledge of yesterday may not be applicable today, this paper will investigate its implication in two knowledge areas; the universe and in medicine.
When people believed that the bible was the science textbook of the day, many scientists thought that the world was only 6000 years old. This was not until the discovery of dinosaur remains dated millions of years. The knowledge of the universe is dynamic and what is science today may be proven wrong in the next century. One of the most common examples of this is in the shape of the world. In ancient days, the world was believed to be flat. With time, this changed, through observations and measurements that were nonexistent before, to the world being spherical. In effect, the school of thought that the earth is flat was discarded, and the new science was that the world is a sphere. Still, modern science disapproved the notion that the earth is spherical, and its observation is that its oblate-spheroid. The discovery of this fact in the late 1950s might have been considered the knowledge of the day. However, today satellite images indicate that, in fact, the plates on the Northern hemisphere and those in the South are not equal. Essentially, the earth is not oblate-spheroid.
In the 1930s, state-of-the-art biological knowledge stated that the number of chromosomes in the human body is 48. This was a theory, but last for a long period such that some scholars advocated for it to be adopted as the fact. In 1956, this changed and through the new technique of observing cells, Albert Levan and Joe Hin Tjio counted them to only 46. This changed the field of medicine and an earlier concept was discarded.
With time new knowledge, will emerge and discard the existing one. Arbesman states that just like uranium, knowledge has a half life and with time will decay. The knowledge about the world will keep on changing and, given the decay of knowledge, so is the field of biology. These changes are not unique to these two fields, but rather to all other areas of knowledge.