سوال ۲۰ کنکور ارشد فیزیک ۱۴۰۲

PART C: Reading Comprehension — PASSAGE 2

Ever since Max Planck introduced the idea of the quantum to the world, physicists have argued about whether reality is more like sand or water. Planck’s famous 1900 discovery that energy is grainy—at least when absorbed or emitted—moved him to label the smallest bits of energy grains “quanta.” But he believed that once emitted, as in light from a fire, those grains merged into smooth, continuous waves, just as water seems a smooth liquid to human perception. [1]

By the mid-1920s, both the wave and particle views of light had gained experimental support, with the additional paradox that electrons—supposedly particles—could sometimes disguise themselves as waves. Into this arena of controversy stepped the famed Danish physicist Niels Bohr, the pioneer of exploring the architecture of the atom. [2] Bohr announced that resolving the wave-particle paradox required a new view of reality, in which both notions shared a role in explaining experimental phenomena. In experiments designed to observe waves, waves you would find, whether electrons or light. In experiments designed to detect particles, you’d see particles. But in no experiment could you demonstrate both at once. [3] Bohr called this viewpoint the principle of complementarity, and it successfully guided the pursuit of quantum mechanics during the following decades.

More recently, as philosopher Slobodan Perović recounts in his book form Data to Quanta, Bohr’s success has been questioned by some physicist and philosophers and even popular science writers. Complementarity has been <u>derided</u> as an incoherent application of vague philosophy expressed in incomprehensible language. [4] But as Perović’s investigations reveal, such criticisms are rarely rooted in any deep understanding of Bohr’s methods. Rather than Bohr’s philosophy contaminating his science, Perović argues, it is his opponents’ philosophical prejudices that have led to misstatements, misunderstandings and misrepresentations of Bohr’s physics. And Bohr can’t be understood by attempting to understand his philosophy, Perović asserts, because philosophy did not guide him—experiments did.

20- In which of the positions marked by [1], [2], [3], or [4] in the passage can the following sentence be inserted?

Einstein, on the other hand, insisted that light quanta traveled through space on their own, behaving like particles later called photons.