At this point in time, there is no known technology which allows for any human being to travel back in time-(even for a single minute). However, as a former History Instructor, I've learned to be very careful when using words such as, "possibility" and "impossibility". Here are some examples:
In 1902, it would have been viewed as "impossible" to fly human beings several feet above ground for just a few minutes. Yet, by 1903, the Wright Brothers conducted their first airplane flight at Kitty Hawke, North Carolina with great success and essentially, defying the naysayers and ridiculers of their day....the Modern Airplane was born. During the mid 1950's, it was still viewed as an impossibility for human beings to travel beyond the heavens and into space. However, by the late 1950's, the Soviet Union launched Sputnik and by the early 1960's, U.S. Astronaut John Glenn successfully orbited the Earth, thereby leading to the Space Age (and Space Race between the U.S. and the U.S.S.R.). The Internet, as a worldwide public utility, has existed for nearly 30 years-(since the mid 1990's). However, if one remembers the earliest days of the Internet-(circa 1996-1997), it was quite limited in design and global scope, as well as intellectual sophistication. By 1998, 2 Stanford University Engineers transformed the Internet with the founding of Google, allowing human beings to conduct research and acquire knowledge at an unprecedented rate and volume thereby establishing the first true worldwide Digital Library.
And so when looking at the late modern and contemporary history of science and technology, we can see that the impossible, has often become-(and can still become)...possible. The pioneers in Science and Technology have ALWAYS found novel and ingenious ways of advancing and refining the technologies of their time. Does this therefore mean that time travel is automatically possible? No, it does not automatically guarantee that time travel is possible, though simultaneously, it does not automatically make time travel an impossibility either.