Yes, that’s true, we can travel time, if we answer the question in its literal meaning. We all travel through time continously every day. Right from your birth, till the time you are reading this sentence you are obliviously travelling through time.
“Nothing is as far away as much as a minute ago.”
Contextually, the question does not have a unambiguous ‘positive’ answer, but there are ways to dissect the question, to interpret it and derive a sensible explanation leading to our answer
Consider the below demonstration.
Jack is a Fifteen year old boy. (Lets call him Jack15.) He wants to desperately meet and talk to 5 years younger self. So Jack15 uses a time machine and does a 5 year time travel to the past and meets him self who is at age 10 (Jack10). To probe this scenario, We will try to analyse it with Behavior Driven Development (BDD in software terminology)
Given — Jack is of age 15 and decides to travel back in time to meet him self at age 10
When — Jack15 time travels 5 year back to meet Jack10 using a time machine.
Then — Jack10 and Jack15 are together and can talk to each other
So far so good, Considering the above case succeeds. Now after five years, Jack10 becomes Jack15(and Jack15 becomes Jack20 and stays in same house as Jack15 and wants to become a football player)
Here, We have a brand new Jack15 who is at age 15, and is ready to travels back in time since the ‘Given’ statement becomes active again followed by When and finally the ‘Then, statement is executed one more time. This will be repeated over and over again whenever Jack becomes 15 and eventually Jack15 gets stuck in an endless time loop.
In conclusion, whenever Jack turns 15 he creates another timeline for himself and this keeps on creating endless number of Jacks ( imagine a house full of Jacks or a football team full of Jacks each with a 5 year age gap with other)
Practically speaking, it is not practical to time travel the way we understand it.
Now lets try to answer another coupled question
Does a Time machine makes a copy of you ? (like another version of you.? )
Lets imagine, to answer this question, you went back in time 10 years and hit your younger self with a knife which should eventually turn into scar on his face, but will this scar should also magically appear on your face right now since your are 10 years older self of you at that time?. ( we’ll no, since we are talking about science here, no magics allowed). What does this mean ? That the time machine just made a copy of you and sent you back in time but what happened to the original you, if you are just a copy ?
The Answer is that the Time machine when it exist, will make a copy of you to port you physically at a different time, destroying the original version of you.
So do you want to do it ?
However , this answer is true even when there is no time machine involved but only natural progression of time in our life
what are you today is a copy of your yesterday self + 1 day lived.
where 1 day lived are your delta changes for the day
today = yesterday + 1 multiplied by the delta changes of the day
today = decade ago + 10 years of delta changes
So today if you happen to meet your decade ago self in a restaurant, you will realize that both are different personalities with different choices, preferences, way of talking and most probably you both will order different food to eat and dislike each others choice of food
what did time do to you ? destroyed the original version and created a new version of you. This is natures time machine.
Time changes everything except something within us which is always surprised by change.
Customized time machine created by humans does not exists and wont exist in future but there is a default time machine provided by nature working on immutable functions and methods based on predefined rules which humans cannot override.
Like all software have bugs and is potentially vulnerable to hack, humans are trying to break the code for now, until then there is only one possible way provided by nature itself to time travel to past, which is ofcourse not a physical form of time travel but a virtual form
No points for guessing , it is via our memories we can go back in time indisputably.
Well, how about Time Reversal,
As in, to put smoke back inside a burnt ciggerate itself sounds impossible.
And about Time travel to Future, Yes It is possible! but a topic for another day.
Finally i would end this topic with a quote for those who didnt like my explanations
Regret for wasted time is more wasted time.