The statement must be supported by evidence, and it must hold true investigation after investigation, experiment after experiment. Scientists in all disciplines ask a question, propose a solution, investigate it, and see if it what they propose holds. .

             One might say now, "Since a scientist proposes a solution to a question, and that proposal might be true, doesn't the truth really come from within?" For the scientist, truth does not come from within. He proposes something, an idea. He does not know if it is true or not. It is a guess. The truth only becomes truly evident when that idea has been verified time and again. The truth is out there, the scientist just has to find it. The proposal is a step on the path to finding the truth. .

             It should be noted that scientists need not propose a solution. Many people, over the years, have wondered what the speed of light was. Galileo, Romer, Huygens, Foucault, and Michelson all devised experiments for measuring the speed of light. They did not initially have predictions as to what it might be. All they knew was that is was fast. They all found values, and as measuring technology and experiments became more advanced, the numbers that were produced got closer and closer together. We now know that the speed of light is around 3.00 x 10^8 m/s. We did not have an initial guess, but we now know the truth. .

             It should also be noted that scientific truth changes over time. As methods and technologies develop, we can examine our world with more detail and accuracy. The atom is a case in point. Dalton's theory was that matter was made up of billiard ball-like particles called atoms. Later, it was found that atoms were made up of even smaller particles called electrons, protons, and neutrons. Today, we have discovered even smaller particles that make up electrons, protons, and neutrons. The truth today is not what it was in Dalton's time. .

             So, for a scientist, truth is reality.