Scientific knowledge contradicted by young Earth theories

Overview
Young Earth theories generally contradict vast amounts of mutually-supportive scientific data while offering very little (if any) understanding in exchange. This page is for documenting the extent to which young Earth theories directly contradict centuries of documented scientific evidence and analysis, and attempt to decimate the vast body of scientific understanding about the prehistoric past by replacing its answers with vagueness, fake explanations and unanswered questions.

Contradictions
The contradictions are loosely grouped into observations which need explaining (and which have been explained by science), conclusions we have reached based on observational data, and areas of knowledge which would no longer make sense if the Earth were substantially younger than we think it is.

These lists are not by any means complete, but are being compiled as time permits.

Observations

 * the Kâ€“T boundary, remnant of the Cretaceousâ€“Tertiary extinction event 65.5 million years ago
 * magnetic striping of the sea floor

Conclusions

 * much of geology:
 * ice ages
 * plate tectonics
 * formation of geological structures
 * the Pleistocene era, from 1.806 million (Â±5,000) years to 11,550 years before present, during which the last major glaciations took place
 * the formation of Lake Agassiz circa 11,000 BC
 * the existence of Lake Bonneville from about 30,000 BC until about 15,000 BC
 * the existence of a substantial number of other prehistoric lakes
 * the Younger Dryas climate event, circa 10,000 BC
 * The Bornean Clouded Leopard (Neofelis diardi) is believed to have differentiated from the mainland Clouded Leopard (Neofelis nebulosa) some 1.4 million years ago, when the land bridge from Borneo and Sumatra to mainland Asia became submerged. (Find details about land bridge: geological evidence that it existed, etc.)

Areas of Knowledge

 * all of cosmology: the evolution of stars and galaxies simply does not happen on a timescale of less than millions of years, aside from cataclysmic events like novae; our understanding of even those events, however, requires inhumanly vast timescales for the processes preceding and following
 * much of astronomy: our theories about the formation of various planetary bodies require rather more than 10,000 years in which to operate (by several orders of magnitude); the accuracy of these theories figure significantly in a number of ways related to the future of humanity
 * biological reverse-engineering heavily relates to the evolutionary history of each species examined, which is completely incompatible with young Earth theory
 * much of geology:
 * underpinnings of anthropology, which make extensive use of what we have learned about specific prehistoric cultures, many of which existed before 10,000 BC, not to mention evolutionary theory
 * About half of the Neolithic age (~8500 BC - ~3500 BC) and all of the Mesolithic and Paleolithic eras of humanity
 * the Maglemosian culture, ~7500 BC - ~6000 BC
 * the Natufian culture, ~12,000 BC - 10,200 BC
 * the Azilian cultures, ~10,000 BC
 * the Miocene epoch:
 * Chororapithecus abyssinicus, an ape that lived about 10â€“10.5 million years ago
 * the Jurassic geological time period, ~200 Ma (million years ago) to ~145 Ma
 * Archaeopteryx, the earliest known bird, which lived 155-150 million years ago in what is now southern Germany
 * 380 million year old fossilized trees found in New York

Implications
Implications of belief in young Earth theories (extrapolated from our understanding of the young Earth worldview):
 * Spending resources on geology is overrated, as much of the point of studying geology depends on a false belief about the age of the earth; about the only use for geology is knowing the best places to look for oil deposits.
 * Resources spent on astronomy are almost certainly wasted, beyond a sort of aesthetic appreciation of the celestial portion of God's Creation; much of the spending on astronomy is in pursuit of cosmological theories which (obviously) must be wrong as they require timespans in the billions of years, which is plainly impossible.

Links

 * video: The Atheist Delusion: satirical piece written from the point-of-view of a fictional Young Earth creationist
 * Creationist Timescale: if all of Earth's known history were compressed into the 6016 years of the Creationist timeline