prompter: Write a story about a person who discovers they have the ability to time travel and than teleports back into Ancient Rome, he gets there with a smartphone and a power bank. How could the history change?

assistant: Once upon a time, there was a young man named Jake who had a powerful curiosity about the world. One day, he was walking through a park when he stumbled upon a mysterious and ancient looking stone. He picked it up and noticed a strange energy radiating from it.

Intrigued by this newfound energy, Jake decided to take the stone home with him and experiment. After a few days of tinkering, he realized that the stone had the power to manipulate time and space. He could travel back and forth through time, and even teleport to any location he wanted.

With his newfound power, Jake decided to take a journey back to Ancient Rome. He packed his bag with a few essentials, including a smartphone and a power bank. When he arrived in Ancient Rome, he was met with amazement from the locals.

With his technological advancements, Jake quickly became a powerful figure in the city. He used his smartphone to show the Romans the wonders of the modern world. He used his power bank to provide electricity to the city, which allowed them to create new inventions and further their development.

At first, the Romans thought of Jake as a god, but as his influence grew, they began to realize the power of technology and the potential of Jake's time traveling ability. Jake's presence in Ancient Rome changed the course of history, as the Romans were able to use his knowledge to advance their society, and eventually create a thriving and powerful empire.

Jake's story is one of time travel, exploration, and technological advancement. His journey shows us that even the smallest of actions can have a huge impact on history.

assistant: Once upon a time, there was an ordinary man named Johnny Time. One day, Johnny Time discovered he was suddenly transported to ancient Rome with his smartphone and a power bank. However, since Johnny Time does not understand Latin, and there was no cellphone network or wifi in ancient Rome, Johnny Time was unable to communicate with the Romans. The Romans thought Johnny Time was a barbarian spy who performed witchcraft with his glowing brick and Johnny Time was arrested and had an untimely demise.
Years later, archeologists were baffled at the excavation of what appears to be parts from a modern smartphone inside ancient Roman ruins and concluded unethical companies are using the ruins as landfills for electronic waste. Thus ends the tragic tale of Johnny Time and his smartphone.

prompter: I don't like the name Johnny, can you please change it to something more English, like a typical name from Great Britain please thanks

assistant: How does Charles sound? I changed the name in the story:

Once upon a time, there was an ordinary man named Charles Time. One day, Charles Time discovered he was suddenly transported to ancient Rome with his smartphone and a power bank. However, since Charles Time does not understand Latin, and there was no cellphone network or wifi in ancient Rome, Charles Time was unable to communicate with the Romans. The Romans thought Charles Time was a barbarian spy who performed witchcraft with his glowing brick and Charles Time was arrested and had an untimely demise.
Years later, archeologists were baffled at the excavation of what appears to be parts from a modern smartphone inside ancient Roman ruins and concluded unethical companies are using the ruins as landfills for electronic waste. Thus ends the tragic tale of Charles Time and his smartphone.

assistant: Once upon a time, there was an ordinary man named Everett Edwards. One day, Everett Edwards discovered he was suddenly transported to ancient Rome with his smartphone and a power bank. However, since Everett Edwards does not understand Latin, and there was no cellphone network or wifi in ancient Rome, Everett Edwards was unable to communicate with the Romans. The Romans thought Everett Edwards was a barbarian spy who performed witchcraft with his glowing brick and Everett Edwards was arrested and had an untimely demise.
Years later, archeologists were baffled at the excavation of what appears to be parts from a modern smartphone inside ancient Roman ruins and concluded unethical companies are using the ruins as landfills for electronic waste. Thus ends the tragic tale of Everett Edwards and his smartphone.

prompter: Okay, Everett sounds great! But I liked the last name "Time". So maybe keep that?

assistant: James

assistant: Bob was shocked when he found he teleported back to Ancient Rome. He was a good son and he first tried to call his mother. Of course that didn't work, she wasn't born yet. As he realized where he was, it began to dawn on him: he could change history. He could teach them all about the enzymatic properties of myosin, which he had been studying in detail for the last 10 years. He could also teach them about the industrial revolution but to be honest he hadn't payed much attention in history class.

prompter: I want the story to focus on how the smartphone and the powerbank could be used by the main character to help advance knowledge and civilization back then

assistant: I'm sorry if this missed what you focus on and failed to satisfy the requirement. What about this version:
Bob was shocked when he found he teleported back to Ancient Rome. He was a good son and he first tried to call his mother. Of course that didn't work, she wasn't born yet. As he realized where he was, it dawned on him: he could change history, and he had to use his "future technology" wisely —— even with the power bank, the phone would last no longer than several weeks. Getting enough reputation was, well, it took a fair share of his precious battery to perform some "super accurate divination" and "magic", letting alone the pain to learn Latin from the beginning. Why not just bring more stuff that would work fine without internet!
Without proper materials, even building a primitive steam engine would be impossible since there was nothing to seal and hold the pressure. So the story began with metallurgy. To be fair it was impossible to force-feed a bunch of chemistry into those ancient scientists, so the best he could do was to dig through his files for something like the relationship between carbon content and hardness and beg them to believe. 
There was one thing that might make a difference: showing the Romans the toxicity of lead and stopping them from using lead as a condiment. Perhaps this would win them some time to understand enough modern science. 
During the painstaking attempts to build some processing equipment and finally a primitive engine, he tried writing some detailed operation guide, hoping the Romans could replicate these tools and finally find out the science behind them on their own. Another gift from the future was calculus, though he suspected if anyone could accept it and find it useful in decades since he just wasn't a math teacher. It suddenly hit him: knowledge need to spread easier. Well, now he also had to reinvent the good old Gutenberg printing press.
By the time the screen would never light up again even turning on just once per several weeks, the first Newcomen atmospheric engines, though without Newcomen, were struggling in mines with the Watt one quietly waiting in a sketchy blueprint. Time for home, and hopefully this was not going to bring the whole human civilization to an early end...