Despite all of our advancements in science, physics, and astronomy, we still don’t know what approximately 80%-90% of the matter in the Universe is. But this isn’t a completely hopeless situation; there is a great deal we do know about this mysterious substance, provisionally named dark matter. For example, we know it’s there and we know where it is.
'Uncertainty'—it's not a word that we generally associate with science. Science conjures images of certainty, solid results, and constant improvement by increment. There's a certain irony then, that when we strip nature down to its fundamental limits, there remains an implicit, irremovable, intrinsic uncertainty. No matter how precise our measuring devices and methods become, no matter how clever our scientists, nature has imposed a limit on what we can know. And we are certain of that. That's what the Heisenberg Uncertainty Principle describes. And it isn't just a factor in quantum physics. It infiltrates our lives in a number of surprising ways.
The Planetary Society’s LightSail 2 project launches from Kennedy Space Center in Florida, as part of the US Air Force’s STP-2 mission. It will be carried by a SpaceX Falcon Heavy rocket, enclosed within Prox-1 — a small satellite built by Georgia Tech students.
Even from a modern perspective, it isn't difficult to understand why Einstein's theory of Special Relativity caused such a paradigm shift in physics and science in general. Until its introduction in the 1905 paper, On the electrodynamics of moving bodies, the scientific consensus was that space and time were separate entities—a stage on which the events of the universe played out. Special Relativity would not only unite space and time to a single entity—"Spacetime"—it would also lead to the conclusion that the events of the Universe shape that stage. Spacetime in Space Relativity and later General Relativity was no longer passive, it was a player in the events around it. Einstein proposed that clocks observed to be moving at high speeds would tick more slowly than those at rest.