frontier, it's just the next frontier. you -- you need all the rest of that infrastructure and that could take time. i would say decades, not centuries, for sure. >> i got to know, would you want to go on blue origin? or -- or any space flight? >> well, so i am an astrophysicist. and so, you know, i do the math and, you know, how high up does blue origin go? relative to a school-room globe, it goes the thickness of two dimes above. and so, for me -- and -- and then, you're boldly going where hundreds have gone before. so for me, i would -- i would get on a spaceship if you're going to take me somewhere. the moon, mars, or beyond. then, there is a destination and -- and that's what i would want. >> just very briefly before we go, all these unidentified craft that have been seen. where -- where do you stand on this? >> it's not a matter of stance. it's -- i've said this before. just look at -- by the way, there are 3 billion smartphones in the world. and each one can take a