interaction
esiegel | October 9, 2013"Even in hindsight, I would not change one whit of the Voyager experience. Dreams and sweat carried it off. But most of all, its legacy makes us all Earth travelers among the stars." -Charley Kohlhase
In the early days of space exploration, it was quite a feat just to get up and out of Earth's atmosphere. There's are two good, simple reason for that, of course: first, it takes a lot of energy to go up that high...
Image credit: Nathan Bergey of http://psas.pdx.edu/orbit_intro/.
and second, if you don't get your spacecraft moving really fast, you're just going to fall back to Earth once you…
esiegel | October 4, 2013"Time is a sort of river of passing events, and strong is its current; no sooner is a thing brought to sight than it is swept by and another takes its place, and this too will be swept away." -Marcus Aurelius
Every one of us does our best to come up with an accurate picture of reality, and that includes the Universe, from the smallest subatomic particles to the largest scales fathomable. But given how bizarre and counterintuitive some of our physical laws are -- even at a fundamental level -- this can be a daunting task for even those of us who are professional theoretical physicists.
Image…
esiegel | August 17, 2012"We don’t understand how a single star forms, yet we want to understand how 10 billion stars form." -Carlos Frenk
The Universe has been around for a long time: nearly 14 billion years, to the best of our knowledge. When it was very young, there were absolutely zero stars in it, while today, there are hundreds of billions of galaxies, each of which contains anywhere from a few billion to many trillions of stars.
Image credit: NASA, ESA, and the Hubble Heritage (STScI / AURA) - ESA / Hubble Collaboration
The galaxy shown above, NGC 2841, is very similar to our own Milky Way. Approximately the…
esiegel | June 27, 2012"I found I could say things with color and shapes that I couldn't say any other way -- things I had no words for." -Georgia O'Keeffe
When it comes to the Universe, it isn't just the stuff that's in it that's important.
Image credit: 2MASS Extended Source Catalog (XSC).
It's also how all that stuff interacts with itself and everything else. To the best of our knowledge, there are four fundamental forces in the Universe, and they're all essential to our existence.
Image credit: Stichting Maharishi University of Management, the Netherlands.
Some of them are familiar, like gravitation. On the…