The Omphalos hypothesis takes its name from the title of an 1857 book, Omphalos by Philip Henry Gosse. Gosse argued that in order for the world to be "functional," God must have created the Earth with mountains and canyons, trees with growth rings, Adam and Eve with hair, fingernails, and navels (omphalos is the Greek word for "navel"), and that therefore no evidence that we can see of the presumed age of the earth and universe can be taken as reliable. The idea has seen some revival in the 20th century by some creationists, who have extended the argument to light that appears to originate in far-off stars and galaxies (though other creationists reject this explanation).
Yet consistent with their core beliefs, many creationists hold that Adam and Eve had no navels, and that the trees in the Garden of Eden had no growth rings.
In 1921 Bertrand Russell suggested, somewhat facetiously, that the universe might have been created five minutes ago. A variation of this notion is “Last Thursdayism,” which posits that our world came into being then. Some variants suggest that the previous universe was destroyed that day, but then recreated exactly as it was (not unlike saving a computer’s contents on a secondary hard drive so that they can be fully recovered if the main drive crashes). This hypothesis offers the seeming advantage of rescuing predictions that the universe was going to end on a certain day. It did end, we are told, but then was restored exactly as it was.
Last Thursdayisn has been dogged by the heresies of Last Wednesdayism and Last Fridayism. Needless to say, none of these hypothesises is capable of any empirical testing. Failing Karl Popper’s refutability criterion, they are fun anyway.