What is Wave–particle duality?
'''Wave–particle duality''' is a concept in [[physics]]. It's the idea that there are things that are both [[Wave (physics)|waves]] and [[particles]]<nowiki/>. [[Physicist]]s who studied light in the 1700s and 1800s had an argument about whether light was made of [[particle]]s or [[Wave (physics)|waves]]. Light seems to act like both. At times, light seems to go only in a straight line, as if it were made of particles. But other experiments show that light has a frequency and [[wavelength]], just like a [[sound wave]] or water wave. Until the 20th century, most physicists thought that light was either one or the other, and that the scientists on the other side of the argument were simply wrong. == Present situation == [[Max Planck]], [[Albert Einstein]], [[Louis de Broglie]], [[Arthur Compton]], and [[Niels Bohr]] worked on this problem. Current scientific theory is that all particles act both like waves and like particles.<ref>{{cite book | title = Quantum Mechanics: an introduction | author = Walter Greiner | publisher = Springer | year = 2001 | isbn = 3-540-67458-6 | url = https://books.google.com/books?id=7qCMUfwoQcAC&dq=wave-particle+all-particles&pg=PA29 }}</ref> This has been verified for elementary particles, and for compound particles like atoms and molecules. For [[macroscopic]] particles, because of their extremely short wavelengths, wave properties usually cannot be detected.<ref>{{cite book| title=Quantum physics of atoms, molecules, solids, nuclei, and particles | url=https://archive.org/details/quantumphysicsat00eisb_941 |author1=R. Eisberg |author2=R. Resnick |name-list-style=amp |publisher=John Wiley & Sons|edition=2nd|year=1985|isbn=047187373X|pages=[https://archive.org/details/quantumphysicsat00eisb_941/page/n34 59]–60|quote=For both large and small wavelengths, both matter and radiation have both particle and wave aspects.... But the wave aspects of their motion become more difficult to observe as their wavelengths become shorter.... For ordinary macroscopic particles the mass is so large t