"Uncertainty is inevitable at the frontiers of knowledge."
In the context of the article from which this came from, the author of the article explains that scientists never side with a claim with absolute certainty. This is because even if they feel confident with their experiment, they still feel uncertain. Scientists do not want to declare that something is undeniably true because there is a chance that later on someone else can disprove their hypothesis. For example, a long time ago Ptolemy developed the geocentric theory and it was a widely believed fact that the universe revolved around the earth. Then Copernicus, Kepler, and Galileo came up with the heliocentric theory, in which the earth, the moon, and other planets revolved around the sun. With the newly invented telescope, Galileo had new methods of understanding the composition of space. Scientists even today remain at least a little skeptical of the accuracy of their claims because future knowledge and technology could disprove their claims. Even in chemistry class, when we write labs, we never use the word "prove" because it implies an absolute certainty. Scientists do not want to proclaim an absolute certainty so they will not be completely wrong if someone disproves them later on.
