Happy Birthday Carl Sagan!

Aside

Happy birthday to one of my heroes, Carl Sagan. He was a scientist who was a consummate educator.

In science it often happens that scientists say, “You know that’s a really good argument; my position is mistaken,” and then they would actually change their minds and you never hear that old view from them again. They really do it. It doesn’t happen as often as it should, because scientists are human and change is sometimes painful. But it happens every day. I cannot recall the last time something like that happened in politics or religion.

Keynote address at CSICOP conference (1987), as quoted in Do Science and the Bible Conflict? (2003) by Judson Poling, p. 30

New (old) forms of water and the scientific method

We’re used to dealing with normal everyday water (H2O). And when we freeze it we get ice. But there are interesting unusual versions of ice. We’re used to the normal version of ice that melts at 0 °C. But there are others. There’s even the horrifying (and fictional) ice-nine.

But what about different versions of water? It turns out that around 1970 the Soviets and the US were working on a new version of water: polywater. They had managed to condense a version of water that looked oily, froze at -40 °C, boiled at 150 °C, and was denser than normal water. More and more scientists got in on making this, and there was a real worry that the US was falling behind the Soviets in learning about polywater.

The only problem was all the scientists were wrong. It turns out that all of the polywater made was contaminated. By sweat. It was just sweaty water. While various scientists were analyzing the stuff, they came up with various theories on what it was and why it behaved the way it did. These theories were quickly tossed aside and other theories proposed. This is how science works. And when someone realize that due to the small sample sizes, everyone had made a similar mistake that gave them a contaminated sample, the whole thing was tossed.

There have been other, more popular, cases where a scientific claim is made and it lives for a while before being discredited: cold fusion, faster than light neutrinos. This kind of science, where the hope for fame may be ahead of rigorous science, is sometimes called pathological science.

I think the one with the faster than light neutrinos doesn’t belong in this list though. The scientists involved got results that even they thought were wrong. They just didn’t know why, and were asking other scientists to vet their work and tell them where they were wrong (a sensor was installed wrong). They didn’t mean for the public to read about it. But when others published about it, the writers made it seem that they thought they had proven Einstein wrong, which wasn’t what was going on.

The Fukushima disaster could have been averted, and was

Remember the earthquake that sent a tsunami which flooded the Fukushima Dai-ichi nuclear plant? Remember the flooding, and meltdown, and ongoing radiation leaks? Very dramatic, wasn’t it. What most people don’t know is that there was another nuclear reactor in Onagawa, closer to the epicenter than Fukushima, that didn’t have any problems, except some flooding in the basement.

It turns out that the designer of this plant, Yanosuke Hirai, wanted to make sure that the plant was protected. He wanted the plant to be built 50 feet above sea level, with a cooling system that would work even if the water receded. The original sea wall was supposed to be 10 feet (bureaucrats), and he wanted 49 feet. In a culture of conformity he managed to get the sea wall to 46 feet. The Fukushima sea wall could only protect against a 19 foot tsunami.

On 11 March 2011, the earthquake released a 43 foot tsunami. Hirai’s stopped it. His plant shut down cleanly, and was used as an evacuation center in Onagawa. Fukushima’s sea wall was overwhelmed and the plant is still releasing radiation.

Bacteria in your gut may be lined to rheumatoid arthritis

A study at NYU suggests that certain bacteria in your intestines may lead to getting arthritis. Remember, most of your cells aren’t really your cells. Most of the cells in your body are bacteria in your intestines.

It looks like one particular bacteria, Prevotella copri, are more abundant in people just developing rheumatoid arthritis. Is the bacteria bloom a cause of arthritis, or is it a symptom of a different cause?

The bacteria in our gut is different from person to person, and most of the people in this study were from New York. So further work is needed to see if this holds true on different continents.

Bohemian Gravity

Timothy Blaise recently wrote his master’s thesis on string theory, and then did a super video of him explaining it while singing a cappella to Queen’s Bohemian Rhapsody. This is so full of win.

Here are they lyrics:

Is string theory right?
Is it just fantasy?
Caught in the landscape,
Out of touch with reality
Compactified
On S5 or T*S3

Space is a pure void
Why should it be stringy? 
Because it’s quantum not classical
Nonrenormalizable
Any way you quantize
You’ll encounter infinity
You see

Quanta
Must interact
Via paths we understand
Using Feynman diagrams
Often, they will just rebound
But now and then they go another way
A quantum
Loooooop
Infinities will make you cry
Unless you can renormalize your model
Of baryons, fermions
And all other states of matter

Curved space:
The graviton
Can be thought of as a field
But these infinities are real
In a many-body
Loop diagram
Our results diverge no matter what we do…
A Quantum Soup (any way you quantize)
Kiss your fields goodbye
Guess Einstein’s theory wasn’t complete at all!

I see extended 1-D objects with no mass
What’s their use? What’s their use? Can they give us quark plasma?
What to minimize?
What functional describes this
String?
Nambu-Goto! (Nambu-Goto)
Nambu-Goto! (Nambu-Goto)
How to quantize I don’t know
Polyakov!
I’m just a worldsheet, please minimize me
He’s just a worldsheet from a string theory
Reperametrized by a Weyl symmetry!

Fermi, Bose, open, closed, orientable?
Vibrations
Modes! They become particles (particles!)
Vibrations
They become particles (particles!)
Vibrations
They become particles (particles!)
Become particles (particles!)
Become particles (many many many many particle…)
Modes modes modes modes modes modes modes!
Oh mamma mia mamma mia,
Such a sea of particles!
A tachyon, with a dilaton and gravity-vity-VITY

(rock out!)

Now we need ten dimensions and I’ll tell you why
(anomaly cancellation!)
So to get down to 4D we compactify!
Oh, Kahler!
(Kahler manifold)
Manifolds must be Kahler!
(Complex Reimannian symplectic form)
If we wanna preserve
Any of our super-symmetry

(Superstrings of type I, IIa and IIb)
(Heterotic O and Heterotic E)
(All are one through S and T duality)
(Thank you Ed Witten for that superstring revolution and your new M-theory!)

(Maldecena!)
(Super-Yang-Mills!)
(Type IIB String!)
Dual! Dual!
(In the AdS/CFT)
(Holography!)

Molecules and atoms
Light and energy
Time and space and matter
All from one united
Theory

Any way you quantize…

Lyrics and arrangement by Tim Blais and A Capella Science
Original music by Queen

And here’s a link to his master’s thesis.

Muscle dissection today

Today the 7th graders saw how muscles work to move limbs by dissecting a chicken wing. They worked in groups to cut into a raw chicken wing so they could see the muscles. Then they pulled on the muscles to see how they moved the wing. Digging deeper, they saw the silvery tendons that connect muscle to bone. Deeper still, they saw the ligaments that hold the bones together.

Hopefully no one will have chicken for dinner tonight. 🙂

Aricebo is 50 years old today

The Arecibo observatory, the largest single dish radio observatory, opened 50 years ago today in Puerto Rico. It occupies a karst sinkhole and is 305 m (1000 feet) across. The dish is spherical instead of parabolic, which means that it can focus in a broad region instead of only one point. Specifically, the error of a spherical mirror is the same at all locations, but there would be varying amount of astigmatism if the mirror were parabolic.

Some of its observations are:

  1. Mercury’s period of rotation is 56 days, not 88 days as was thought.
  2. Provided first solid evidence of neutron stars.
  3. Discovery of the first extrasolar planets.