With all the important things going on in our individual lives, not to mention the 24/7 news cycle—who’s got time to think about what life will be like for our species 500 or even 5,000 years from now? Well, lots of folks actually.

One of them is Michio Kaku.

The physicist lays out his vision of man’s future in space, and how that future might be driven by an increasingly hostile Earth in his latest book, The Future of Humanity: Terraforming Mars, Interstellar Travel, Immortality and Our Destiny Beyond Earth. It takes readers on a journey from the science fiction thinking of the past to the real life scientific realm of  human space travel today. He joins the Morning Shift to share his thoughts on how far humans might be able to travel through space and why it may be a necessity in the years in come.