Quotes About Astrophysics

Without a doubt, the most spectacular way to die in space is to fall into a black hole.

In the beginning, there was physics. Physics describes how matter, energy, space, and time behave and interact with one another. The interplay of these characters in our cosmic drama underlies all biological and chemical phenomena. Hence everything fundamental and familiar to us earthlings begins with, and rests upon, the laws of physics. When we apply these laws to astronomical settings, we deal with physics writ large, which we call astrophysics.

Dark energy is a mysterious pressure in the vacuum of space that acts in the opposite direction of gravity, forcing the universe to expand faster than it otherwise would.

The most accurate measurements to date reveal dark energy as the most prominent thing in town, currently responsible for 68 percent of all the mass-energy in the universe; dark matter comprises 27 percent, with regular matter comprising a mere 5 percent.

The day gets about one second longer every 67,000 years.

While most branches of science have ascended in this era, the field of astrophysics persistently rises to the top. I think I know why. At one time or another every one of us has looked up at the night sky and wondered: What does it all mean? How does it all work? And, what is my place in the universe?

After 7 or 8 billion years of such enrichment, an undistinguished star (the Sun) was born in an undistinguished region (the Orion arm) of an undistinguished galaxy (the Milky Way) in an undistinguished part of the universe (the outskirts of the Virgo supercluster). The gas cloud from which the Sun formed contained a sufficient supply of heavy elements to spawn a few planets, thousands of asteroids, and billions of comets.

Turns out, while all light pollution is bad for astrophysics, the low-pressure sodium lamps are least bad because their contamination can be easily subtracted from telescope data. In a model of cooperation, the entire city of Tucson, Arizona, the nearest large municipality to the Kitt Peak National Observatory, has, by agreement with the local astrophysicists, converted all its streetlights to low-pressure sodium lamps.

How do you study something that cannot possibly get your clothes dirty? How do astrophysicists know anything about either the universe or its contents if all the objects to be studied are light-years away? Fortunately, the light emanating from a star reveals much more to us than its position in the sky or how bright it is.

Our planet Earth has a diameter of 0.04 light-seconds. Neptune's orbit spans 8 light-hours. The stars of the Milky Way galaxy delineate a broad, flat disk about 100,000 light-years across. And the Virgo supercluster of galaxies, to which the Milky Way belongs, extends some 60 million light-years.

Had Earth been much closer to the Sun, the oceans would have evaporated. Had Earth been much farther away, the oceans would have frozen.

Had Earth been much closer to the Sun, the oceans would have evaporated. Had Earth been much farther away, the oceans would have frozen. In either case, life as we know it would not have evolved.

The Universe was opaque until 380.000 years after the Big Bang.

One substantial hunk of junk led to the formation of the Moon. The unexpected scarcity of iron and other higher-mass elements in the Moon, derived from lunar samples returned by Apollo astronauts, indicates that the Moon most likely burst forth from Earth's iron-poor crust and mantle after a glancing collision with a wayward Mars-sized protoplanet.

Dark matter particles should be passing through your body right now.

In our own solar system, for example, everything that is not the Sun adds up to less than one fifth of one percent of the Sun's mass.

If a particle can fall into a black hole, it can come out of a white hole.

the universe had a beginning. The universe continues to evolve. And yes, every one of our body's atoms is traceable to the big bang and to the thermonuclear furnaces within high-mass stars that exploded more than five billion years ago.

As we've known from the beginning, dark matter does, indeed, exert gravity, to which ordinary matter responds. But that's it. After all these years, we haven't discovered it doing anything else.

Nebulium was simply the signature of ordinary oxygen doing extraordinary things.

Swiss-American astrophysicist Fritz Zwicky.

thermal radiation left over from the Big Bang

The cosmic perspective enables us to grasp, in the same thought, the large and the small, from a universe that began in a space far tinier than the period at the end of this sentence to one that is now many billions of light-years across.

The largest black hole that could have evaporated since the big bang would have to have been smaller than an atomic nucleus.