When I looked for defining boundaries or ideas of the modern world, they varied between the 1800s until the contemporary society, so I wanted to hear the opinion of professionals!
By time period, I mean 1850s or 1900s. By ideas, I mean democracy or capitalism or sorts.
My second post in reddit, hope I did it right!
Because "modernity" is a very complex notion and/or phenomenon, there are many, many different 'starting points' for the modern world, depending on which strain of modernity you're invoking.
In my field (Continental Western Europe) here are some common anchor-points that we offer in European history survey classes:
ca. 1500: modern conception of the world, with circumnavigations of the globe (Columbus, Da Gama, Magellan)
ca. 1450: modern conception of History, with the late Renaissance scholars postulating themselves as "modern" (its first usage of the notion of a self-conceived, self-conscious break with a so-described prior past--the "Medieval"... which comes 'in-between' the Classical and the Modern eras)
1640s-1680s: the beginning of modern scientific method (Galileo, Newton, Boyle, Decartes, Bacon, etc.)
1750s-1770s: the Enlightenment, for modern ideas involving the application of reason to social problems (Locke, Rousseau, etc.), and also on the accumulation and categorization of modern knowledge (Diderot's encyclopedia, etc.)
1789 (the French Revolution) as good peg-point for modern nationalism, modern politics as well as idealistic/utopian-framed political revolution. (birth of "left" and "right", socialism, conservatism, etc.) (add on to that, 'modern' warfare of the Revolutionary and Napoleonic wars, involving mass armies, mass conscription, etc.)
1780s to 1840s: industrialization, first in Britain, then moving to continental Europe by the 1830s/40s
1770s: modern ideas about political economy (with Adam Smith, etc.)
1880s-1900: the first era of globalization (economic and cultural), closely tied up with the emergence of global capitalism AND imperialism/colonialism
1900: modernism as an artistic movement
post-1918: modernism as a literary movement (Joyce, etc.) and (pace Fussell) modern(ist) "irony" and/or memory
post-1945: modern architecture
Historians can and do argue about every single one of these, of course.. Indeed, I doubt any historian in the world would agree with the dating of all of the above 'modern' turning points... (instead wanting to push many backwards/forwards).
Also, a note: all of the biographical identifiers (Smith, Galileo, etc.) are just given as recognizable sign-posts... most specialists of these eras will say that, contrary to any sort of "great man" theory, each of these thinkers/etc. represented a culmination of gradual change (rather than creating change by dint of personality and/or genius)
Are you looking at the start of the early modern period or something else?