Earth
milhayser | December 2, 2014On Pharyngula, PZ Myers criticizes a stirring new short film imagining humanity's presence on the far-flung worlds of our solar system. PZ writes, "There’s nothing in those exotic landscapes as lovely and rich as mossy and majestic cedars of the Olympic Peninsula, or the rocky sea stacks of the nearby coast." So let's not get ahead of ourselves in turning Earth into a dust bowl. On Respectful Insolence, Orac considers the demerits of a new monograph on 'integrative oncology,' saying it's a false dichotomy polarizing aspects of actual science and pure wishful thinking. And on Uncertain…
dr. dolittle | January 3, 2014 Image from: The Poo Prejudice | The Arid Land Homesteaders League www.plantfreak.wordpress.com
Okay, here is something rather interesting that I came across today. Scientists have discovered that dogs will align their bodies with the Earth's magnetic field before excretion. What is even more amazing is that the scientists actually observed over 5,000 pee breaks and over 1,800 defecations to come to this conclusion. Their findings suggest that when the magnetic field is stable, dogs will stand in-line with the North-South axis while avoiding the East-West axis. However, when the field…
esiegel | October 2, 2013"Ignorance more frequently begets confidence than does knowledge: it is those who know little, and not those who know much, who so positively assert that this or that problem will never be solved by science." -Charles Darwin
There are problems with science today, no doubt. With all the knowledge we've accumulated about the Universe, from the smallest subatomic scales to the farthest recesses of deep space, there are still realms and regimes where our best theories fail, where the predictions and the data don't match, and where no known explanation is sufficient for the phenomena that shows up…
esiegel | September 27, 2013"I have an existential map. It has 'You are here' written all over it." -Steven Wright
So just because the Ask Ethan series is becoming way more popular than I can handle -- I've got more than 200 questions that I'm sitting on by now -- doesn't mean you should stop sending your questions! There are some really good ones, and today's comes from Robert Plotner, who asks:
When maps of the CMB are depicted, they are shown as a flattened ovoid. How does this correlate to our view of the sky which is a sphere? For example, a global map of the Earth is either distorted to show it in two dimensions…
esiegel | August 30, 2013"Being told about the effects of climate change is an appeal to our reason and to our desire to bring about change. But to see that Africans are the hardest hit by climate change, even though they generate almost no greenhouse gas, is a glaring injustice, which also triggers anger and outrage over those who seek to ignore it." -Sigmar Gabriel
With all of the scientific issues subject to politicization in this world, there's arguably none that raises such strong emotions as the issue of global warming and climate change. This is the final installment of a three-part series on how one could…
esiegel | August 29, 2013"We make the world we live in and shape our own environment." -Orison Swett Marden
If you had never heard of global warming before, how would you figure out whether it's real or not? And if it is real, how would you figure out what humanity's role in it is? To answer this, I've decided to do a three-part series on how you'd go about figuring this out, putting aside all politics, economics, opinion and any other non-scientific factors. If you missed part 1, you can check it out here; today we're going to build on that and talk about what determines the temperature of a planet with an…
esiegel | August 28, 2013"There is no question that climate change is happening; the only arguable point is what part humans are playing in it." -David Attenborough
It's been a long time since I've written anything on this blog about global warming, climate change, or most Earth-based environmental topics in general. After all, I'm a physicist -- an astrophysicist in particular -- and although I'm well-versed in the physics of the Earth and in science in general, it's not my particular area of expertise.
Image credit: NASA, Johnson Space Center, Apollo 17 crew.
Recently, I've had a number of requests to take a…
esiegel | August 9, 2013“Next to reasoning, the greatest handicap to the optimum development of Man lies in the fact that this planet is just barely habitable. Its minimum temperatures are too low, and its maximum temperatures too high. Its day is not long enough, and its night is too long... These factors encourage depression, fear, war, and lack of vitality. They describe a planet, which is by no means perfectly devised for the nurturing or for the perpetuation of a higher intelligence.” -James Thurber
It's been just about three years, now, since the first announced discovery of a planet in another star system…
esiegel | June 5, 2013"You can spend too much time wondering which of identical twins is the more alike." -Robert Brault
You've of course heard by now the news that Kepler, the most successful and prolific planet-finding mission of all time, has probably reached the end of its useful lifespan.
Image credit: NASA / Kepler Mission / Wendy Stenzel.
With nearly 3,000 planet candidates under its belt, including many approximately Earth-sized (and some even smaller), and many within their parent star's habitable zone, we now know that, at least planet-wise, we're not alone in our galaxy.
Image credit: NASA Ames /…
esiegel | February 15, 2013“Don't wake me for the end of the world unless it has very good special effects.” -Roger Zelazny
It's always the ones you least expect that get you the worst, it seems. I went to bed last night excited that Asteroid 2012 DA14, a 200,000 ton asteroid, was going to pass within just 28,000 km (or 17,000 miles) of Earth's surface, which would make it the closest pass of an asteroid that large that we've ever observed.
Image credit: NASA / JPL Near-Earth Object Program Office.
I thought that would be the best way to celebrate today, which would be Galileo's 449th birthday. After all, it was…
esiegel | August 23, 2012"It is always wise to look ahead, but difficult to look further than you can see." -Winston Churchill
We've come a long way in this Universe. Over the past 13.7 billion years, we've formed the light elements out of a sea of protons and neutrons, cooled and expanded to form neutral atoms for the first time, gravitationally collapsed hydrogen and helium gas clouds to form the first stars, borne witness to generations of stellar deaths and rebirths, lived through the formation of hundreds of billions of galaxies and the clustering together of thousands or more galaxies into clusters, filaments,…
esiegel | August 3, 2012"How old would you be if you didn't know how old you are?" -Satchel Paige
Today marks another year and another trip around the Sun for me. For you, and me, and everything on Earth that makes it through another year on this world, there's a whole lot we get to experience.
Image credit: NASA / ISS Expedition 13.
Some things are tiny: the Earth's rotation slows by about two millionths of a second each year, while some are large: we hurtle over 900 million kilometers in outer space as we orbit around the Sun. Our Earth spins just over 366 times on its axis, while our one revolution around the…
esiegel | July 13, 2012"For most of the history of our species we were helpless to understand how nature works. We took every storm, drought, illness and comet personally. We created myths and spirits in an attempt to explain the patterns of nature." -Ann Druyan
Here on Earth, we are well aware of how devastating storms can be. From hurricanes to flash floods, an unpredictable change in weather can turn a serene setting into a catastrophe in no time at all. The clouds that fill the skies can often portend what type of weather is coming, and to me, the most impressive and fearsome of all is the rare and remarkable…
esiegel | June 30, 2012"Don't go around saying the world owes you a living. The world owes you nothing. It was here first." -Mark Twain
So, you've been around a while, seen all sorts of things, and learned an awful lot about the world, solar system and Universe that we live in. But how well do you know it, really?
Image credit: NASA / Lunar and Planetary Laboratory.
To scale and in order, these are the eight planets you know so well. There are the four rocky worlds of our inner solar system: Mercury, Venus, Earth, and Mars, and the four gas giants that dominate the outer solar system: Jupiter, Saturn, Uranus, and…
esiegel | June 26, 2012"We came all this way to explore the Moon, and the most important thing is that we discovered the Earth." -Bill Anders, Apollo 8 astronaut
From hundreds of miles up, the International Space Station speeds around the Earth, completing 18 orbits a day, looking down on us and returning some absolutely fabulous images.
Image credit: Fyodor Yurchikhin and the Russian Space Agency Press Services, of Greenland from the ISS.
But what you may not appreciate is that my favorite images taken from the ISS weren't taken by American Astronaut Don Pettit (better known as @astro_Pettit), but rather by a…
esiegel | June 22, 2012"Some prophecies are self-fulfilling
But I've had to work for all of mine
Better times will come to me, God willing
Cause I can't leave this world behind" -Josh Ritter
You sure can't leave this world behind. At least, not very easily. The reason for it, of course, is gravity.
Image Credit: Physclips, via the University of New South Wales' School of Physics.
Here on the surface of the Earth, the gravitational potential well is pretty large; large enough that there's no easy way off. Sure, you can pour a huge amount of energy into a rocket to try and overcome this gravitational potential…
esiegel | June 19, 2012"Soon the earth will tilt on its axis and begin to dance to the reggae beat to the accompaniment of earthquake. And who can resist the dance of the earthquake, mon?" -Peter Tosh
Every year, there are two special days where every place on Earth receives the same amount of sunlight -- 12 hours -- split evenly between night and day: the equinoxes!
Image credit: timeanddate.com.
Like all known objects that revolve around another due to gravity, the Earth rotates along its journey around the Sun. But on those two days of the equinox (from the Latin, meaning "equal nights"), the Earth's axis-of-…
esiegel | June 8, 2012"Building one space station for everyone was and is insane: we should have built a dozen." -Larry Niven
Here on the solid ground of the Earth, the Sun and Moon rise and set on a daily basis. During the hours where the Sun is invisible, blocked by the solid Earth, the stars twirl overhead in the great canopy of the night sky.
Image credit: Chris Luckhardt at flickr.
In the northern hemisphere, they appear to rotate around the North Star, while in the southern hemisphere, the stars appear to rotate about the South Celestial Pole. The longer you observe -- or for photography, the longer you…
esiegel | June 1, 2012"The moon shuts off the beams of the sun as it passes across it, and darkens so much of the earth as the breadth of the blue-eyed moon amounts to." -Empedocles, ~450 B.C.
Less than two weeks ago, I saw my first annular eclipse, with some spectacular results at the moment of maximum eclipse.
From my first eclipse expedition, to False Klamath Cove, on the coast in northern California.
This happens, of course, because -- from our point of view -- the Moon appears to pass in front of the Sun, blocking a fraction of the light coming from it.
Image credit: NASA / Solar Dynamics Observatory.
And…
cevans | September 13, 2011A couple of months ago, I wrote a piece here on Universe exploring the ideas of the futurist Gerard K. O'Neill, who designed far-out but ultimately quite pragmatic environments for human habitation in space in the mid-1970s. In that article, I touched briefly on the notion of the "Overview Effect," a phrase coined by the writer Frank White to describe the profound insight -- characterized by a sudden awareness of life's interconnectedness and the frailty of our planet -- experienced by astronauts gazing down at the Earth from space.
Frank White is the author of The Overview Effect: Space…