I had always been fascinated by Howard Hughes. There were unfortunate circumstances in his life regarding his mental health that definitely curtailed his abilities and what certainly would have been further advancements in technology at that time. 

If one were to read of his business accomplishments over many decades, especially his ability to expand his empire and his wealth, one would see that he could be considered a precursor to Elon Musk. 

His various technologies he created in real life became the trigger for my "The Time Traveling Wanderers" book where he accidentally found an ability to create a portal to any time in history. This "any time in history" was left generic since I did not want to make this too far outlandish and have him traveling hundreds of millions of years into the past. I created a technical limitation where traveling into the past was limited due to power consumption required for traveling into extreme times into the past. 

I also created a situation that would ultimately be the story behind my second book, "Tale of the Fallen Angels", where Howard Hughes triggered the "doomsday scenario". He was not fully aware of his technology's potential and risk. Well, of course without his knowing he set in motion this scenario where he did not know was even a problem that could endanger the universe.