It seemed simple enough when she told you how to travel through time. So simple that a child from four thousand years in the future had done it on a whim. Four thousand years is a long time for advancements to be made but you thought with a few expansions on the tech needed you could do it.
The first time machine prototype’s particle collider was undersized and the necessary expansion of space though the eighth dimension caused it to implode.
The second time machine had a collider three times as long and looping straight down into the earth. During the test firing it opened a portal to an alternate earth with mole people. You think the portal closed when you collapsed the shaft.
The third time machine was government funded. They thought you were building a machine to help them further violate the public’s privacy. After a successful first test of the viewing machine, you activated another implosion collider and left with important documents to be sold to the highest bidder.
The fourth time machine would have succeeded if not for those meddling kids and their dog.
The fifth time machine you built on the moon. The low gravity made construction fairly easy but the death threats from people who didn’t like the new craters you put on the moon during testing kind of soured the mood.
The sixth time machine fit in the trunk of a car thanks to the advancements you made while working on the moon. You couldn’t get the car you wanted but settled for a VW Beetle. It didn’t come back from its test drive.
The seventh time machine was the last machine you created. It didn’t work but it did put a new crater on Earth. That’s when the child’s mother (the child who explained time travel to you) appeared and explained you were one time machine failure away from destroying the entire planet.
“It was a nice effort,” she said patting you on the head, “but maybe wait a few more centuries before trying again.”