Someone tells you that scientific knowledge cannot be changed or modified. how would you answer this statement?

Scientific knowledge can be modified. This is because all the scientific principles that are existing now is not certain for all possible conditions. Scientific knowledge is not directly given to us, human minds work the effort of unveiling the unknown. Thus, scientists are slowly discovering the science of all natural phenomena. Along the way, they could come up with misinterpretations. Let me give a concrete example. When J.J. Thompson proposed the Plum-Pudding model, it was the widely accepted theory in the field of atomic science. However, when Rutherford did his golden foil experiment, he disproved Thompson's model and proposed the Planetary Model. Therefore, scientific knowledge is an ongoing process. Scientists would always want to disprove each other, not because they want to compete with each other. They want to discover the truth together with what they have to the best of their abilities. They are never content with just one simple principle according to one scientist. It will always be verified by a group of fellow scientists.

In the 21st century where technology is exponentially progressing, scientists would discover more of the basic principles. Hence, we would expect that scientific knowledge is constantly changing and modifying.

Neptune is the eighth planet from the sun. it was the first planet to get its existence predicted by  mathematical calculations  before it was actually seen through a telescope on sept. 23, 1846. irregularities in the orbit of  uranus  led french astronomer alexis bouvard to suggest that the gravitational pull from another celestial body might be responsible. german astronomer johann galle then relied on subsequent calculations to   spot neptune via telescope. previously, astronomer galileo galilei sketched the planet, but he mistook it for a star due to its slow motion. in accordance with all the other planets seen in the sky, this new world was given a name from greek and roman mythology — neptune, the roman god of the sea.

Kinetic energy = 1/2mv^2. since the mass is constant we can form a ratio of it's kinetic energy at 60 divided by that at 30 to see ke(60)/ke(30) = +(60^2)/30^2). this may be said to 300% increase.