Your Elementary School Teachers Were Right. So were Copernicus, Galileo, Kepler, Newton, and Einstein.

We all learned that the that there are there are nine planets sometime in grade school. You may have used the mnemonic "My Very Educated Mother Just Served Us Nine Pizzas." There are now only eight, because astronomers decided that Pluto along with Ceres, Iris, and perhaps about 50 others are dwarf planets. So maybe we should memorize "My Very Educated Mother Just Served Us Nuts."

We also learned that these planets orbit the Sun. I bet none of us ever questioned how we know this. Why would we? It is established scientific fact, right?

So why would anyone think Galileo Was Wrong; The Church Was Right. This link is to a website that promotes Geocentrism, the idea that the Earth is not only the center of the solar system, but the center of the universe. I've been through this website looking for one thing - an explanation of orbits, because it's a straightforward calculation if you start with Newton's 2nd law and his law of universal gravitation. My students who have had PHY 211 can go back to Unit N of the text book and read chapters 12 and 13, and I can show anyone else who's interested how it works. [In the interest of scientific honesty, Mercury presents a small problem that took Einstein to solve.] So my challenge is that a geocentrist must be able to write a force law and derive a equation of motion for the planets that reproduce the orbits with the Earth as the force center.

Let's illustrate the problem:
Here's a Flash simulation of the heliocentric (Sun-centered) solar system. Only Mercury, Venus, Earth and Mars are shown. Press play and pay close attention to Mars. You see that Mars follows a nearly circular orbit as explained by Newton.

Now look at the Ptolemaic or geocentric (Earth-centered) solar system. Here Mars, Jupiter, Saturn, Uranus, and Neptune are shown. Again press play and pay attention to Mars. Press the circle button and the animation will trace out the orbit.

See the problem? [Again in the interest of scientific honesty, many of these geocentrism web sites don't use a purely Ptolemaic system, they use the Tychonic model where the Earth is the center, the Sun and the Moon orbit the Earth and the rest orbit the Sun. But the orbit problem among others remains.]

So why would anyone believe in a theory put to rest 400 years ago? Galileo Was Wrong; The Church Was Right goes to great lengths to couch its arguments in criticizing Einstein's theory of relativity and other physics, but when you examine closely their argument comes down to…

Because the Bible says so.

Here are the verses (from NIV) commonly used by geocentrists:

Joshua 10:12-13
12 On the day the LORD gave the Amorites over to Israel, Joshua said to the LORD in the presence of Israel: “Sun, stand still over Gibeon, and you, moon, over the Valley of Aijalon.” 13 So the sun stood still, and the moon stopped, till the nation avenged itself on its enemies, as it is written in the Book of Jashar. The sun stopped in the middle of the sky and delayed going down about a full day.

Ecclesiastes 1:5
5 The sun rises and the sun sets, and hurries back to where it rises.

Psalm 96:10
10 Say among the nations, “The LORD reigns.” The world is firmly established, it cannot be moved; he will judge the peoples with equity.

Psalms 104:5
5 He set the earth on its foundations; it can never be moved.

Isaiah 66:1
1 This is what the LORD says: “Heaven is my throne, and the earth is my footstool…

1 Chronicles 16:30
30 Tremble before him, all the earth! The world is firmly established; it cannot be moved.

Amos 8:9
9 “In that day,” declares the Sovereign LORD, “I will make the sun go down at noon and darken the earth in broad daylight.

Micah 3:6
6 Therefore night will come over you, without visions, and darkness, without divination. The sun will set for the prophets, and the day will go dark for them.

Jeremiah 15:9
9 The mother of seven will grow faint and breathe her last. Her sun will set while it is still day; she will be disgraced and humiliated. I will put the survivors to the sword before their enemies,” declares the LORD.

If you read this literally, then I guess it's clear that the Earth is stationary and the Sun moves.

Now for the irony. Answers in Genesis, a creationist site, finds geocentrism embarrassing. The site goes to great lengths to debunk geocentrism. But Ken Ham, the founder of Answers in Genesis, is the man who built the Creation Museum in Petersburg, KY. The museum has Adam and Eve and says T. Rex ate coconuts. He is also building Ark Encounter near Cincinnati, OH that will also feature dinosaurs.

What do you think is Ken Ham's reason for believing in creation?

Some Unsolicited Advice for My Students, Both Current and Past

"You can not tell how the dots will connect." Steve Jobs

In this post, I am doing something, I almost never do - give advice when it hasn't been requested, but I hope you will read what I say and consider it.

Earlier this week, I posted to FaceBook a link to an article in The New Republic entitled "Bad Job Market: Why Media Is Wrong About Value Of College Degree."The gist of the piece is that "[Nothing] has stopped the nation’s leading news outlets from regularly publishing terrifying stories about college graduates unable to find decent work, particularly during economic downtimes when unemployment and insecurity were on the rise." The author's claim is that these reports are just wrong.

I happen to agree with the author. The U.S. Census Bureau reports that "Adults age 18 and older with a bachelor’s degree earned an average of $51,554 in 2004, while those with a high school diploma earned $28,645." Those without a high school diploma earned an average of $19,169." If you happen to have a STEM (science, technology, engineering, math) degree than your prospects are even brighter. Check out the data from PayScale.com.

But there's more to the story.

A degree is not a guarantee of a job in the field. I have often used my friend's experience to show the utility of a physics degree. One Ph.D friend after graduating went to work for the research and development department of Goodyear Tire Co. Another used his skills with computers and landed a position at an Austrian bank. Another one who earned an M.S in physics is leading the development of chips for the cell phone industry. Yet another friend has had success in IT. Four physics students of mine from Whittier College went on to engineering jobs at Boeing.

John Shumway, physics professor at Arizona State, commented on my FB post that universities are promoting the idea that a degree is some sort of ticket to a job, and he's right - they are not. There's a big push in the California community colleges to create more Associate degrees. Why? For those transferring to a four-year institution, the A.A. and the A.S. won't mean much beyond the sense of personal accomplishment. The biggest reason for the push is someone decided that a community college would be rated on the number of degrees it awards. Some CCs are actually going through the records to find former students who are within a few courses of a degree and encouraging them to return and enroll in those courses.

But there's more to the story.

Life sometimes sucks. And it sucks now. The guy who worked for Goodyear - he is now seriously underemployed. Prof. Shumway related that he knows too many people with all levels of degrees who are having trouble finding jobs. Just a couple of days ago, I chatted with a former student of mine who recently graduated and was getting phone interviews, but couldn't get any further.

But there's more to the story.

Very few people follow a path in life. I won't bore you with the various forks in the road I either chose or were chosen for me. The important thing is what Steve Jobs said. "You can not tell how the dots will connect."

So now for the two pieces of advice.

1. Everyone will tell you to study and get good grades. True, but in a few years, no one will ask you what grade you got, because no one will care. What will make the difference in the long run are the skills you develop.

2. There's some truth to the saying "it's not what you know, it who you know." Develop a network. Keep in touch with your classmates. If you have the chance to go to SACNAS or the Society of Toxicology or a meeting of any professional organization, GO! Say "Hi", shake hands, exchange business cards, follow up. You never know.

Good luck!

Transformers 3 - Dark of the Moon

Saturday night I went to see Transformers 3 - Dark of the Moon. Did I like it? Well, it was loud and I was out of the house for three hours.

As I was watching it though, I began to wonder about some physics (SPOILER ALERT) when Sentinel Prime began transporting the remains of Cybertron. So I said to myself, "Self. What sort of gravitational effects would that have on the Earth?"

Let's start with Cybertron. I will need to find its mass. So I'll need its radius and an estimate of its density. I need an image to make measurements, but I couldn't find an image from the movie, so working from memory, I made one. It appeared to me that Cybertron would be much bigger than the Earth. By the time Earth was saved, my estimate is that about 1/16 of Cybertron (by volume) had been transported. Then the Transformers' planet had a radius five times larger than Earth's. Since the war had destroyed much of Cybertron, only the cubic structural elements were left, so instead of a solid, we have a lot of empty space. Judging from the width of the structural beams, I'd judge that 105/125 of the planet is empty.

Now for geometry. The volume of a sphere is

The radius of the Earth is about 6400 km. So the volume of the transported Cybertron is approximately 2 X 10^22 cubic meters.

We can get from the mass from the density and the volume. Aluminum has a density 2700 kg/m^3, steel has a density of 7500 kg/m^3, and 4500 kg/m^3 for titanium. Now maybe the Transformers are using graphene for their structures, but doesn't their technology look metal-based and not organic? So I'll use the density of titanium as an average value. Plugging in the numbers yields for Cybertron's mass 1 X 10^26 kg. Yikes! Seventeen times more mass than the Earth.

Before I start with the gravitational effects, I need an estimate of how far Cybertron is from Earth. It wasn't very far - maybe 1 Earth radius away; that's 6400 km (4000 miles).

The biggest effect would be that the Earth would in effect become a moon of Cybertron; technically though, they would be a planetary binary system. Binary systems orbit about their common center of mass. If we calculate the center of mass, (it's okay to think center of gravity) it would be located 470 km beneath the surface of Cybertron,

How long would it take for the Earth to orbit Cybertron? Just under 8 minutes. Let's start with Newton's 2nd law of motion. Substitute Newton's law of universal gravitation, and the expressions for the centripetal acceleration and the speed of an object in circular motion. Now solve for the period.

Night time every 4 minutes.

Now let's consider the tides. Tides occur because of the Moon, the Sun, and the Earth's rotation. The major effect is called the principal lunar semidiurnal constituent and is due to the Moon. In short the Moon's gravitational pull is slightly larger on the side of the Earth nearer the Moon than on the far side; physicists call this a gravitational gradient.

So all I have to calculate is the gravitational force on opposite sides of the Earth and subtract the two to estimate the gradient. I find that Cybertron's gradient is three hundred million times stronger than the Moon's. I wouldn't be living near any large body of water.

It's a good thing Optimus Prime is on our side.

P.S. I noticed that when Decepticons came through the portal, they maintained their motion. That's what Newton's first law of motion would demand. But when the transportation of cCybertron occurred, it didn't maintain its motion. Violation!!!

Listening to Music: Friends, Wine, Audiophilia, and Las Vegas

Dedicated to Steve and Wayne.

Every January, I travel to Las Vegas to attend the Consumer Electronics Show, in particular to hear the latest in high end audiophile equipment. [But really it's just an excuse to meet up with my Chicago lawyers and eat and drink.] Each time I make sure to visit the Burmester suite to hear what I hope will one day be my stereo system.

Now all I need is $500,000. Then the neighborhood will be introduced to Miles Davis and John Coltrane in true style.

Inevitably we get around to talking about the differences between tubes and solid state. Tubes? Vacuum tubes. Most people under the age of 40 may never have seen a vacuum tube, because the transistor and then the IC chip has made tubes ancient history in every industry except high end audio.

Now to the point. I never realized how complex it is to listen to music. You know that old saw about a person uses only 20% of the brain. I'm not exaggerating much when I say that we are using nearly all of brain. The cerebrum is involved in keeping time, parts of the midbrain is involved in the emotion, the frontal lobe takes all the info and does the higher level processing. I can't do justice to all the neuroscience involved, but I can recommend Daniel Levitin's "This Is Your Brain On Music: The Science Of A Human Obsession."

Now back to some Miles Davis and a nice Sauvignon Blanc.

The End of an Era?

Talk about mixed emotions.  Atlantis blasted off at 8:29 PDT this morning - perhaps the last manned mission ever.  And this is why I am both sad and happy.

I came of age during the Cold War's race to the moon.  I remember watching the Apollo astronauts launch from Cape Canaveral, land on the moon, and splash down in the ocean.  The reason I'm a physicist can probably be traced to the space program.  That's why I'm sad.

So why would I be happy?  I can't think of a single scientific accomplishment of the Shuttle program. One could point to the mission that put the Hubble Telescope into orbit. Plus the Chandra X-ray Observatory, Magellan Venus, the Galileo Jupiter, and the Ulysses solar probes, and the Compton Gamma Ray Observatory.  Great science.  Let's not forget the shuttle was used to repair the Hubble, too.  But those probes all could have been launched with conventional rockets, and it would have been less expensive to build a new Hubble Telescope than to fix it with the Shuttle.  Don't even get me started on the International Space Station.

I love NASA, I love space exploration, and I love all the technology that has flowed from the space program.  I want NASA to get as much federal funding as possible, but I want good science.