"Dark Matter" and "Dark Energy" are Terms That Hide Ignor...

We can measure the influence of this thing we call dark energy, which is forcing an acceleration of the expanding universe. We don't know what that is, we don't know anything about it, other than what it's doing to the universe. Then 85 percent of the gravity of the universe has a point of origin about which we know nothing. We account for all the matter and energy that we're familiar with, measure up how much gravity it should have — it's about one-sixth of the gravity that's actually ope...

 Losing the Human Perspective in the Vastness of the Cosmos

When I pause and reflect on our expanding universe, with its galaxies hurtling away from one another, embedded within the ever-stretching, four-dimensional fabric of space and time, sometimes I forget that uncounted people walk this Earth without food or shelter, and that children are disproportionately represented among them. When I pore over the data that establish the mysterious presence of dark matter and dark energy throughout the universe, sometimes I forget that every day—every twe...

 The Strong Anthropic Principle

The weak anthropic principle is not very controversial. But there is a stronger form that we will argue for here, although it is regarded with disdain among some physicists. The strong anthropic principle suggests that the fact that we exist imposes constraints not just on our environment but on the possible form and content of the laws of nature themselves. The idea arose because it is not only the peculiar characteristics of our solar system that seem oddly conducive to the development of h...

 The Weak Anthropic Principle

Our very existence imposes rules determining from where and at what time it is possible for us to observe the universe. That is, the fact of our being restricts the characteristics of the kind of environment in which we find ourselves. That principle is called the weak anthropic principle. (We'll see shortly why the adjective weak" is attached.) A better term than "anthropic principle" would have been "selection principle," because the principle refers to how our own knowledge of our existenc...