We don't know. We can go back to within nanoseconds of the Big Bang, around 14.6 billion years ago, but that event makes it impossible to go further. It may be that time only began then - which is why we can't back further, because there is nothing to go to - or it may be that time does go back well beyond that. Whether to only a couple of weeks, or another 20 trillion years, or for an infinite time, is up to what you think.Or possibly a loop in time,Where future and past come together.
in about the 1700's
94 whole earths 94 whole earths
Heat
Schools have existed at least as far back as the bronze age...prior to the iron age. But there is little similarity between those early schools and the ones we have today. Back then, education was available only to wealthy families who didn't need to labor in the fields to survive, and schools were very few and far between.
Pi is infinite and has no end.
I have no clue
5,000
Traces do not go back that far in history.
In 1892, John Froelich invented and built the first gasoline/petrol-powered tractor in Iowa. The history of the engines with in tractors go back as far as 1850.
14000 ago
Make that several thousand years!
The history of human flight doesn't go very far back in time.
I haven't seen a history text book in many years, so my information goes only as far as I can remember.
That depends on how far back you want to go. A difference engine was considered as far back as 1786. Babbage create his first one in 1822.
How far back does family go back
The breed history of the Singapura does not go far back in history they have only been seen since 1991. This is a well known cat now.
1800km - 1900km