...[we] has left nothing durable to signalize his stay upon this planet. [we]eventually dies to the honest regret of [our] associates.
Humanity is the higher meaning of our planet, the nerve that connects this part of it with the upper world, the eye it raises to heaven.
…most of the damage we cause to the planet is the result of our own ignorance.
Unfortunately, we haven't found many very old rocks on Earth because our planet's surface is constantly renewed by plate tectonics, coupled with erosion.
There's this very vulnerable planet of ours with finite resources. Architects and designers have, I think, a fair responsibility for conserving energy and materials, and making things durable.
It bears mentioning that the Milky Way is only one of 150 billion galaxies visible to our telescopes - and each of these will have its own complement of planets.
What a privilege to be here on the planet to contribute your unique donation to humankind. Each face in the rainbow of colors that populate our world is precious and special.
We should recognize that on the day that we are born, our glass is half full. In America your chance to fill your glass the rest of the way up is greater than it is anyplace else on this planet.
Just knowing that there's somebody else out there - that what's happened on this planet has also happened in many other places - that might change our lives in a very subtle way, but it's interesting to know and worth looking for.
I really believe that if we were from another planet, and we sat down to put our heads together on torture experiments, the concept of sticking a needle into someone and sucking their blood out would probably qualify as a pretty good one.
Our planet's lands and oceans are already stretched to meet the demands of 7 billion people. The human population continues to grow. The search for sustainable solutions is an economic and a moral imperative if we are to create the future we want.
We need a community of nations capable of space flight because we all have to be off this planet sometime in the future. Our sun is going to burn out eventually, and we are not in a sustainable situation.
Of course 'we humans' have a funny relationship with the beings with whom we share our planet. We eat them, we care for them, we admire them, we use them.
Most of the intelligence out there must be artificial intelligence. We keep looking for critters like us living on a planet like ours, where in fact the majority of the intelligence out there is not biological. That would be my argument.
When I was a little kid, we only knew about our nine planets. Since then, we've downgraded Pluto but have discovered that other solar systems and stars are common. So life is probably quite prevalent.
For nearly 2 million years, our ancestors survived and thrived and spread across the planet because they could run other mammals into heat exhaustion.
If the means were available, we could trace our ancestry - yours and mine - back to the first blob of life-like material that came into being on the planet.
I don't feel so sad when somebody dies, Julio, because they fly away to explore the stars and planets. When it's our turn we join them in exploring the universe.
Our foreign policy has made a wreck of this planet. I'm always in Africa... And when I go to these places I see American policy written on the walls of oppression everywhere.
For how many people do you think might yet stand on this planet before the sun grows cold? That's the responsibility we hold in our hands.
We can't feel the rotation of the planet, but in some ways we can because our bodily systems are reacting to it and have it inherent in them. To me, that's such a powerful thought.
