Ontology Warning: You are not logged in. Your IP address will be publicly visible if you make any edits. If you log in or create an account, your edits will be attributed to your username, along with other benefits.Anti-spam check. Do not fill this in! === Microcosmic ontology === There is an established and long philosophical history of the concept of atoms as microscopic physical objects. They are far too small to be visible to the naked eye. It was as recent as the nineteenth century that precise estimates of the sizes of putative physical [[atom]]s began to become plausible. Almost direct empirical observation of atomic effects was due to the theoretical investigation of [[Brownian motion]] by [[Albert Einstein]] in the very early twentieth century. Even then, the real existence of atoms was debated by some. Such debate might be labeled 'microcosmic ontology'. Here the word 'microcosm' is used to indicate a physical world of small entities, such as for example atoms.<ref>{{Cite web |title=Definition of Microcosm |url=https://www.merriam-webster.com/dictionary/microcosm |access-date=2022-09-13 |website=Merriam-Webster |language=en}}</ref> Subatomic particles are usually considered to be much smaller than atoms. Their real or actual existence may be very difficult to demonstrate empirically.<ref>Kaiser, D. 1994. "Niels Bohr's legacy in contemporary particle physics." pp. 257β268 in ''Niels Bohr and Contemporary Philosophy'', edited by J. Faye and H. J. Folse. Dordrecht, Holland: [[Springer Publishing|Springer]]. {{ISBN|978-9048142996}}. s. 4 ("Questions of ontology and particle physics phenomenology"). pp. 262β264.</ref> A distinction is sometimes drawn between actual and [[virtual particle|virtual]] subatomic particles. Reasonably, one may ask, in what sense, if any, do virtual particles exist as physical entities? For atomic and subatomic particles, difficult questions arise, such as do they possess a precise position, or a precise momentum? A question that continues to be controversial is "to what kind of physical thing, if any, does the [[Quantum mechanics|quantum mechanical]] [[wave function]] refer?"<ref name="Isham">Isham, C. J. 1995. ''Lectures on Quantum Theory: Mathematical and Structural Foundations.'' London, England: [[Imperial College Press]]. {{ISBN|1860940005}}. pp. 63β67.</ref> Summary: Please note that all contributions to Christianpedia may be edited, altered, or removed by other contributors. If you do not want your writing to be edited mercilessly, then do not submit it here. You are also promising us that you wrote this yourself, or copied it from a public domain or similar free resource (see Christianpedia:Copyrights for details). Do not submit copyrighted work without permission! Cancel Editing help (opens in new window) Discuss this page