To make a time machine what problems need to be solved 知乎

Such a simple question you still ask, first of all, your acceleration to the speed of light, followed by your solution to the problem of lack of oxygen, and then also with a huge ability to impact the time tunnel mouth to expand it, if the ability to be huge, you can go back many years, if the energy is too small, you arrive at most in the Daoguang years of the Qing Dynasty, so your moments quasi-Ben good ponytail braid a posing as a Qing Dynasty subjects. Don't forget to bring your weapon and medical kit when you go back, there were no antibiotics in those days to prevent bacterial infections. Solar charger also bring, may be used later.