Newton on the Power of Gravity

As he sat alone in a garden, he [Isaac Newton in 1666, age 24] fell into a speculation on the power of gravity; that as this power is not found sensibly diminished at the remotest distance from the centre of the earth to which we can rise, neither at the tops of the loftiest buildings, nor even on the summits of the highest mountains, it appeared to him reasonable to conclude that this power must extend much further than was usually thought: why not as high as the moon? said he to himself; an...

 The Journey of a Fossil

One hundred million years ago, an ammonoid lived in the sea that then separated India from Asia. It died and fell into limy sediments on the seafloor. These sediments grew deeper and hardened into rock. The shell calcified, becoming part of the rock, though maintaining every detail of its structure. India was on the move, drifting on a slab of the Earth's mobile crust toward Asia. The floor of the intervening sea was forced under the Asian continent, back into the hot interior of the planet. ...

 Modern Explorers Must Change Their Methods

Today there remain but a few small areas on the world's map unmarked by explorers' trails. Human courage and endurance have conquered the Poles; the secrets of the tropical jungles have been revealed. The highest mountains of the earth have heard the voice of man. But this does not mean that the youth of the future has no new worlds to vanquish. It means only that the explorer must change his methods.