Ten things you may not know about the solar system | Space | EarthSky

Ten things you may not know about the solar system | Space | EarthSky.




My friend and colleague Dr. Victor Andersen of the Community College of Aurora, CO gave a talk called “Ten Things You May Not Know About the Solar System,” a bit in the sense of David Letterman’s Top Ten List. I thought it was a great talk and so decided to give my own commentary on Victor’s list. While the list is Victor’s, any errors are purely my own.

So here we go:

10 ) The hottest planet isn’t closest to the sun
Many people know that Mercury is the closest planet to the sun, well less than half of the Earth’s distance. It is no mystery, therefore, why people would assume that Mercury is the hottest planet. We know that Venus, the second planet away from the sun, is on the average 30 million miles farther from the sun than Mercury. The natural assumption is that being farther away, it must be cooler. But assumptions can be dangerous. For practical consideration, Mercury has no atmosphere, no warming blanket to help it maintain the sun’s heat. Venus, on the other hand, is shrouded by an unexpectedly thick atmosphere, about 100 times thicker than our own on Earth. This in itself would normally serve to prevent some of the sun’s energy from escaping back into space and thus raise the overall temperature of the planet. But in addition to the atmosphere’s thickness, it is composed almost entirely of carbon dioxide, a potent greenhouse gas. The carbon dioxide freely lets solar energy in, but is far less transparent to the longer wavelength radiation emitted by the heated surface. Thus the temperature rises to a level far above what would be expected, making it the hottest planet. In fact the average temperature on Venus is about 875 degrees F, hot enough to melt tin and lead. The maximum temperature on Mercury, the planet closer to the sun, is about 800 degrees F. In addition, the lack of atmosphere causes Mercury’s surface temperature to vary by hundreds of degrees, whereas the thick mantle of carbon dioxide keeps the surface temperature of Venus steady, hardly varying at all, anywhere on the planet or any time of day or night!

9 ) Pluto is smaller than the USA
The greatest distance across the contiguous United States is nearly 2,900 miles (from Northern California to Maine). By the best current estimates, Pluto is just over 1400 miles across, less than half the width of the U.S. Certainly in size it is much smaller than any major planet, perhaps making it a bit easier to understand why a few years ago it was “demoted” from full planet status. It is now known as a “dwarf planet.”

8 ) George Lucas doesn’t know much about “Asteroid Fields”
In many science fiction movies, spacecraft are often endangered by pesky asteroid fields. In actuality, the only asteroid belt we are aware of exists between Mars and Jupiter, and although there are tens of thousands of asteroids in it (perhaps more), they are quite widely spaced and the likelihood of colliding with one is small. In fact, spacecraft must be deliberately and carefully guided to asteroids to have a chance of even photographing one. Given the presumed manner of creation, it is highly unlikely that spacefarers will ever encounter asteroid swarms or fields in deep space.

7 ) You can make volcanoes using water as magma
Mention volcanoes and everyone immediately thinks of Mount St. Helens, Mount Vesuvius, or maybe the lava caldera of Mauna Loa in Hawaii. Volcanoes require molten rock called lava (or “magma” when still underground), right? Not really. A volcano forms when an underground reservoir of a hot, fluid mineral or gas erupts onto the surface of a planet or other non-stellar astronomical body. The exact composition of the mineral can vary greatly. On Earth, most volcanoes sport lava (or magma) that has silicon, iron, magnesium, sodium, and a host of complicated minerals. The volcanoes of Jupiter’s moon Io appear to be composed mostly of sulfur and sulfur dioxide. But it can be simpler than that. On Saturn’s moon Enceladus, Neptune’s moon Triton, and others, the driving force is ice, good old frozen H20! Water expands when it freezes and enormous pressures can build up, just as in a “normal” volcano on Earth. When the ice erupts, a “cryovolcano” is formed. So volcanoes can operate on water as well as molten rock. By the way, we have relatively small scale eruptions of water on Earth called geysers. They are associated with superheated water that has come into contact with a hot reservoir of magma.

6 ) The “edge” of the Solar System is 1,000 times farther away than Pluto
Most people have been taught that the solar system just goes out to the orbit of Pluto. Today we don’t even consider Pluto a full-fledged planet, but the impression remains. Still, we have discovered numerous objects orbiting the sun that are considerably farther than Pluto. These are “Trans-Neptunian Objects” (TNOs), or “Kuiper Belt Objects” (KBOs). The Kuiper Belt, the first of the sun’s two reservoirs of cometary material, is thought to extend to 50 or 60 astronomical units (AU, or the average distance of the Earth from the sun). An even farther part of the solar system, the huge but tenuous Oort comet cloud, may extend to 50,000 AU from the sun, or about half a light year – more than a thousand times farther than Pluto.

5 ) Almost everything on Earth is a rare element
The elemental composition of planet Earth is mostly iron, oxygen, silicon, magnesium, sulfur, nickel, calcium, sodium, and aluminum. While such elements have been detected in locations throughout the universe, they are merely trace elements, vastly overshadowed by the much greater abundances of hydrogen and helium. Thus Earth, for the most part, is composed of rare elements. This does not signify any special place for Earth, however. The cloud from which the Earth formed had a much higher abundance of hydrogen and helium, but being light gases, they were driven away into space by the sun’s heat as the Earth formed.

4 ) There are Mars rocks on Earth (and we didn’t bring here)
Chemical analysis of meteorites found in Antarctica, the Sahara Desert, and elsewhere have been shown by various means to have originated on Mars. For example, some contain pockets of gas that is chemically identical to the martian atmosphere. These meteorites may have been blasted away from Mars due to a larger meteoroid or asteroid impact on Mars, or by a huge volcanic eruption, and later collided with Earth.

3 ) Jupiter has the biggest ocean of any planet 
Orbiting in cold space five times farther from the sun than Earth, Jupiter retained much higher levels of hydrogen and helium when it formed than did our planet. In fact, Jupiter is mostly hydrogen and helium. Given the planet’s mass and chemical composition, physics demands that way down under the cold cloud tops, pressures rise to the point that the hydrogen must turn to liquid. In fact there should be a deep planetary ocean of liquid hydrogen. Computer models show that not only is this the largest ocean known in the solar system, but that it is about 40,000 km deep – roughly as deep as the Earth is around!

2 ) Even really small bodies can have moons
It was once thought that only objects as large as planets could have natural satellites or moons. In fact the existence of moons, or the capability of a planet to gravitationally control a moon in orbit, was sometimes used as part of the definition of what a planet truly is. It just didn’t seem reasonable that smaller celestial bodies had enough gravity to hold a moon. After all, Mercury and Venus have none at all, and Mars has only tiny moons. But in 1993, the Galileo probe passed the 20-mile wide asteroid Ida and discovered its one-mile wide moon, Dactyl. Since then moons have been discovered orbiting nearly 200 other minor planets, further complicating the definition of a “true” planet.

1 ) We live inside the sun
Normally we think of the sun as being that big, hot ball of light 93 million miles away. But actually, the sun’s outer atmosphere extends far beyond its visible surface. Our planet orbits within this tenuous atmosphere, and we see evidence of this when gusts of the solar wind generate the Northern and Southern Lights. In that sense, we definitely live “inside” the sun. But the solar atmosphere doesn’t end at Earth. Auroras have been observed on Jupiter, Saturn, Uranus, and even distant Neptune. In fact, the outer solar atmosphere, called the “heliosphere,” is thought to extend at least 100 A.U. That’s nearly 10 billion miles. In fact the atmosphere is likely teardrop shaped due to the sun’s motion in space, with the “tail” extending tens to hundreds of billions of miles downwind.



Human Body Hacks | VirusHead


I have been seeing more and more about “human body hacks” or sometimes just called “body hacks” and I think they are quite interesting.

Use these with caution and a global disclaimer applies– use at your own risk!!!

Still it is full to read, regardless.



Tips and tricks for those moments when your body is bugging you.


Sinus Congestion? – Relieve sinus pressure by alternately thrusting your tongue against the roof of your mouth, then pressing between your eyebrows with one finger. You may look like Felix Unger, but the motion loosens congestion by making the vomer bone rock back and forth. This bone runs from the nasal passages to the mouth. After about 20 seconds, you’ll feel your sinuses start to drain. (Here’s another one that works for me: Get some Swiss Kriss, a laxative tea. Don’t drink it, but boil some in a pot of water. Being careful not to burn yourself, breathe in the scented steam. Side benefit: it empties your pores too – a great, cheap facial.)


Toothache? – If you can’t get in to see the dentist right away, rub ice on the V-shaped webbed area between your thumb and index finger on the back of your hand. The nerve pathways at the base of that V stimulate an area of the brain that blocks pain signals from the face and hands. If you don’t have ice, you can rub that area too – if it hurts just a little, you’re doing it right. Adding ice to the mix reduces toothache pain by as much as 50 percent more.


Tickle in your Throat? – Play with your ears or clean out that ear wax. When the nerves in the ear are stimulated, it creates a reflex action in the throat. This can cause a muscle spasm that relieves the tickle.

Burned your Hand? – If you singe the skin on your hand, clean the skin and apply light pressure with the finger pads of the other hand. Ice will relieve your pain more quickly, but this method might prevent blistering because it brings the burned skin back to a normal temperature.


Can’t Hear That? – Lean in with the correct ear. Your left ear is better at picking up music. Lean in with the right ear to hear that mumbler friend of yours – it’s better at following the rapid rhythms of speech.

via Human Body Hacks | VirusHead.





Developers vs. Engineers vs. Scientists – Jeremy Kahn’s Dev Blog

I found the following post interesting and (pretty) close to the truth.

(It seems to me that I am probably a hybrid Developer/Engineer.)

I have posted a teaser blurb and the link to the full article below.



Developers vs. Engineers vs. Scientists

SEP 23RD, 2012

I’ve been programming professionally for about 3 years at this point, and I’ve noticed some interesting patterns in other programmers I’ve worked with. One of the key differentiators among programmers is motivation. I’m not referring to an individual’s passion to simply be successful in their career, but rather the type of work they want to pursue. The thing they want to do with computers every day, the types of problems they are interested in solving.

The programmers I have observed generally fall into one of three categories: Developers, engineers, and computer scientists (or just “scientists”). These are not silos. They are ranges on a spectrum, and programmers may find themselves oscillating all over this spectrum throughout the course of a day. However, individuals are usually more comfortable in one of these ranges than the others.



Developers vs. Engineers vs. Scientists – Jeremy Kahn’s Dev Blog.


Are Most Wars the Result of Religious Belief? No.


Are Most Wars the Result of Religious Belief?.




Are Most Wars the Result of Religious Belief?
by Rich Deem

War and Religion

A slew of books by “evangelical” atheists have claimed that most of the world’s suffering (including most wars) are the direct result of religious differences and the discord that it fosters. Such statements are seldom backed up by real evidence (other than citing a handful of wars that seem to be the result of religious differences).1 Does religion really lead to war?

Rich Deem


People can be pretty passionate about their religious beliefs. So, it is not surprising that at least a few famous wars have resulted from disagreements about religion. However, is it true what Sam Harris says that our tendency to slaughter each other “generally have their roots in religion?”2

History of human wars

The history of human warfare goes back to the beginning of recorded history (and, no doubt, well before that). A recent comprehensive compilation of the history of human warfare, Encyclopedia of Wars by Charles Phillips and Alan Axelrod documents 1763 wars, of which 123 have been classified to involve a religious conflict.3 So, what atheists have considered to be “most” really amounts to less than 7% of all wars. It is interesting to note that 66 of these wars (more than 50%) involved Islam, which did not even exist as a religion for the first 3,000 years of recorded human warfare.

U.S.A. – the most religious country

The Myth of Religious ViolenceSince the United States of America is and has been one of the most religious countries over the last 200+ years, if the atheists are correct, the U.S.A. should have been involved in the largest number of religious wars of any other nation. In fact, the United States has been involved in 17 wars, only one of which (the current “War on Terror”) has any religious entanglement. The number of Americans who have died as the result of religious wars is 14.2/year, which is less than the number of people who die yearly from dog bites.4

Conclusion Top of page

The atheist claim that religion is the cause of most wars is shown to be false. The history of human warfare shows that less than 7% of all wars have religious causes. If atheists are correct, the most religious industrial nation, the United States of America, should be involved in more religious wars than any other country. However, only the “War on Terror,” among all 17 American wars, involves a religious component.


Use the Force: How Magicians Can Control Your Decisions | Mind & Brain | DISCOVER Magazine


Use the Force: How Magicians Can Control Your Decisions | Mind & Brain | DISCOVER Magazine.


In magic, choices are rarely what they seem. Magicians know how to manipulate us into a false sense of free will while really holding the puppet strings. Here’s a simple but clever example of a false choice used in magic. Imagine, if you will, the face of an analog clock and think of any hour on the dial (one, two, three….all the way to twelve.) You have a totally free choice. You can even change your mind if you like. Now we’re going to inject some randomness into your decision. Imagine that your finger is the hour hand and, starting at midnight, spell out the hour you chose, moving your finger clockwise by one step for each letter. (For instance, if you thought of seven, you’d spell out s-e-v-e-n, moving the time forward a total of five hours.). After you’ve done that, your finger will be on a new number. Starting there, spell this number, following the same procedure as before, moving your finger around the dial until you land on yet another number. Repeat the procedure one last time, starting where you left off. Remember the hour on which your finger finally lands. This is your selection. You arrived at this number randomly after making a free choice, so I think it’s fair to say that it would be impossible for me to know where your finger ended up. And yet I’m getting an impression right now. In my third eye, a vision of an old mahogany grandfather clock with a swinging pendulum and hand-painted Roman numerals on the dial. The image is ghostly and pale. I can barely make out the face. The hour-hand reads: One o’clock.

This elementary ruse is known as a force. (Try starting with another number and you’ll see why it’s a force.) A force is a way to control a spectator’s selection, be it of a card, number, word, letter—just about anything—and it’s one of the most powerful weapons in magic. There are hundreds of methods. (See for instance, 202 Methods of Forcing, by the great mentalist Ted Annemann.) Forcing gets way more sophisticated, but the basic idea is always the same.

Another familiar force is known as Magician’s Choice, the equivoqué. The idea is to set up multiple paths to the same endpoint. In the simplest version, you deal two cards down on the table and ask the spectator to “remove” to one of them. If your volunteer removes to the card you want to force, you say “Ok, that’ll be yours.” If, however, the spectator points to the other card, you eliminate it, saying “Great, we’ll remove that one.” (Here you’re exploiting the ambiguity in the meaning of the word remove.) Either way the spectator winds up with the same card. This sounds transparent—especially with only two cards—but it gets more sophisticated. In the right hands, it can be incredibly deceptive. By couching choices in ambiguous, open-ended language and exploiting the fact that the spectator doesn’t know what’s coming—assuming they’ve never seen the trick before—the magician can gently control an apparently free decision from among numerous items.