Pick Peat!

Picked a Peck, But Not Peat

Thu, 26 Aug 2010 16:20:00 -0700

MSI Chicago picked their semifinalists for a Month at the Museum, and I’m not amongst them.

Despite the disappointing news, I’ve had a heck of a good time over the last few weeks: I’ve been inspired by your enthusiasm about the project, and the questions you’ve posted.

Although this is the end of my campaign for the Month at the Museum contest, it’s not the end of this project. Thousands of people have visited PickPeat.com in the short time it’s been available, I’ve received heaps of questions, and email from dozens of teachers, students, scientists, and journalists who are excited about making science accessible and relevant.

I’m excited about what’s coming next — I may not get to live at MSI Chicago for a month, but some exciting opportunities are coming out of this project, and I intend to make the most of them.

Thank you all for your encouragement and awesome questions (there are still dozens in the queue, and they haven’t been forgotten). PickPeat.com will be growing — and changing addresses — in the near future, and I’m looking forward to showing you what’s coming next!

Once a coffee bean has been roasted, does it loose its ability to be planted and grow into a plant?

Tue, 24 Aug 2010 15:25:55 -0700

I’m sorry to say you can’t plant a roasted coffee bean and expect it to grow into a tree.

To turn into a tree, a coffee bean needs plenty of water, sun, and good soil — but in the very beginning it simply needs to stay alive.

The very core of a coffee bean is an embryo that can hang out for several months after being harvested. It’s well protected by the shell of the bean, and has the necessary sugars and moisture it requires to stay (barely) alive while it awaits the proper environment to sprout.

Roasting a bean breaks down the sugars, sucks out the moisture, and ruptures the cells inside the coffee bean — great for coffee lovers, but bad news for that embryo.

If you put a reasonably fresh and green coffee bean in a jar of water instead of a roaster, you’d kick off the germination process. Soak it for a day, put it in some loose sand and keep it damp until you see it start to sprout — viola! The beginnings of a coffee tree.

(image courtesy of gimmiecoffee.com)

The Dragon Drop Test: Success!

Fri, 20 Aug 2010 14:01:41 -0700

The Dragon Drop Test: Success! :

SpaceX is working with NASA on the next generation of rockets to take cargo and people into orbit. This is a big milestone for the project — a successful test of the parachute system that brings the “Dragon” capsule back to Earth safely.

Also check out some of the photos and videos on the page from the Falcon 9 rocket launch from earlier this year. Cool stuff.

Hooray for rocket science!

"Science is a way of thinking much more than it is a body of knowledge. — Carl Sagan"

Thu, 19 Aug 2010 10:00:00 -0700

“Science is a way of thinking much more than it is a body of knowledge. — Carl Sagan”

Sonoluminescence. What's up with that?

Wed, 18 Aug 2010 15:53:00 -0700

That’s a heck of a word. “Sono” means sound, and “luminescence” means emitting light without the application of heat. And, as it turns out, sonoluminescence happens under water. Sound, light, water, what?

If you’re confused, you’re in good company: this phenomenon had scientists baffled until the late 1980s.

Simply put, sonoluminescence is a fancy term for how loud sounds can cause tiny flashes of light to appear in water. The basic mechanism is that an intense sound wave can crush tiny bubbles in water, and when those bubbles get crushed, they (sometimes) produce a flash.

What’s fun about sonoluminescence is how extreme the conditions are:

The light flashes are measured in trillionths of a second. That’s millionths of millionths of a second — so small it’s almost impossible to put in understandable terms. For example, you could get six billion flashes in the time it takes you to blink your eye.

While the bubble is being crushed, the walls are moving fast enough to create a supersonic shockwave inside of the bubble.

By the time it starts emiting light, the bubble is 1/100th the width of a human hair, and the gas in the bubble has reached a temperature of around 20,000 degrees Kelvin. That’s three times hotter than the surface of the sun.

Although the density of the energy in the center of a sonoluminescing bubble is incredibly high, it’s so small in size that the only thing you’ll experience is a very, very brief flash of light.

In fact, the flashes of light are relatively difficult for us to see with the naked eye, happen only in tiny bubbles (which are difficult to track), and so short that they’re practically impossible to observe and analyze.

That’s why it took almost fifty years to figure out what was really happening.

The trick was trapping a single bubble in a “standing” sound wave.

A sound wave has “peaks” of high pressure and “valleys” of low pressure. You can hear because the pressure changes in a sound wave cause microscopic hairs in your ears to vibrate, which tells your brain that you’re hearing something.

A standing sound wave is just a sound wave that stays in a constant position, where the pressure rises and falls without pushing in any particular direction. This is a great environment for studying sonoluminescence, because a bubble in a standing wave stays in one spot and undergoes sonoluminescence with each pressure peak: you know where it is, and you can watch it flash as often as you like to gather information about what’s happening.

Cool.

So, where does the light come from?

Due to the heat in the bubble, some of atoms “ionize” and loose an electron. That electron shoots off at tremendous speed, and if it whacks into another ionized atom, the interaction gives off energy — in this case, light.

After figuring out the standing wave trick, scientists have been able to tune their bubbles with different gasses and sizes to alter what kind of light is produced.

So, that’s what’s up with sonoluminescence.

If you’d like to read the account of a guy who’s actually produced and measured sonoluminescence, check out this page.

I hope he forgives me for including this photo:

It’s amazing to think that the little white dot is three times hotter than the surface of the sun.

"No amount of experimentation can ever prove me right; a single experiment can prove me wrong. ..."

Wed, 18 Aug 2010 10:00:00 -0700

“No amount of experimentation can ever prove me right; a single experiment can prove me wrong. — Albert Einstein”

"In science, “fact” can only mean “confirmed to such a degree that it would be..."

Tue, 17 Aug 2010 10:00:00 -0700

“In science, “fact” can only mean “confirmed to such a degree that it would be perverse to withhold provisional assent.” I suppose that apples might start to rise tomorrow, but the possibility does not merit equal time in physics classrooms. — Stephen Jay Gould”

"In all science, error precedes the truth, and it is better it should go first than last. —..."

Mon, 16 Aug 2010 10:00:00 -0700

“In all science, error precedes the truth, and it is better it should go first than last. — Hugh Walpole”

"Every great advance in science has issued from a new audacity of imagination. — John Dewey"

Sun, 15 Aug 2010 10:00:00 -0700

“Every great advance in science has issued from a new audacity of imagination. — John Dewey”

"Facts are not science - as the dictionary is not literature. — Martin H. Fischer"

Sat, 14 Aug 2010 10:00:00 -0700

“Facts are not science - as the dictionary is not literature. — Martin H. Fischer”

A Day at the Museum

Fri, 13 Aug 2010 16:25:00 -0700

OMSI, the Oregon Museum of Science and Industry, is offering free admission for the next couple of days. I stopped by to check out the exhibits and take some photos. There’s some pretty awesome stuff …

This is Samson, the tyrannosaurus rex in residence. It’s amazing to see in person, and hard to overstate how understated this guy’s arms are. Puny!

There are a bunch of other fossils, including a fossil lab where you can talk to people who are working on recovering a triceratops skeleton.

Here’s a couple of really big teeth: from a mastodon and a mammoth, respectively!

OMSI’s Turbine Hall has some pretty sweet electrical exhibits, including a Jacobs Ladder (here’s a closeup of the plasma arc):

… some pretty nimble robots:

… and a 20 foot tall Rocketdyne rocket motor:

That said, the most awesome thing I found was the first known instance of Einstein’s famous E=MC^2 equation, in his own handwriting:

Very, very cool.

It took me an hour to put this together — I can’t wait to see what I could do with an entire month!

"Research is what I’m doing when I don’t know what I’m doing. — Wernher Von..."

Fri, 13 Aug 2010 10:00:00 -0700

“Research is what I’m doing when I don’t know what I’m doing. — Wernher Von Braun”

Revenge of The Perseids

Thu, 12 Aug 2010 16:00:00 -0700

Tonight is the peak of the Perseid meteor shower. If you find yourself outside tonight, it’s worth staring at the sky for a bit. Even in the city, you should see the occasional streak of light as ancient pieces of comet dust burn up in our atmosphere at tens of thousands of miles per hour.

Cool.

Unless it’s cloudy, in which case, I’ll leave you with this photo: NASA’s Astronomy Picture of the Day for August 12th.

What occurs if I fail to shut down my portable electronic device during landing/takeoff?

Thu, 12 Aug 2010 15:36:00 -0700

Probably nothing — people forget to turn off their cell phones, laptops, games, and music players all the time.

However, “probably nothing” is more risk than the airline industry is willing to accept, and for good cause: you don’t want things going wrong on a plane that’s packed with people and thousands of gallons of fuel, all travelling at hundreds of miles per hour.

So, what could happen as a result of operating portable electronic devices on an airplane?

Here’s the general idea: all electronic devices create and absorb radio waves. They say so, right on the package! Look in the manual for pretty much anything that takes batteries, and you’ll find a notice that says something like:

“This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) this device may cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.”

A perfect example of this interference is the weird buzzing that comes from a speaker sitting close to a mobile phone. That buzz represents radio waves emitted by the phone: they’re absorbed by the wiring and are converted into electrical pulses, which get amplified and sent to the speaker.

All computers operate on pulses of electricity, so it’s easy to see that radio waves and computers might interfere with each other. Since commercial airplanes depend on computers for almost everything, you can understand why interference from electronic devices is considered a bad thing!

Of course, the airline industry and the FAA (Federal Aviation Administration) are all very aware of this issue. All of the computer and communication systems that go into commercial airplanes are thoroughly tested in the presence of all sorts of electromagnetic radiation, including pretty much every kind of portable electronic device you can buy.

In reality, the risk that your cellphone or laptop could crash a plane is extremely low, bordering on impossible. The airline industry knows this, and the FAA knows this.

So why can’t you use your phone on an airplane?

That’s all about the FCC — the Federal Communications Commission. The problem is that mobile phones in airplanes have the potential to disrupt mobile phone networks on the ground.

Mobile phone networks are designed for people who are on the ground, where the signal from your phone is absorbed or reflected by the things around you — buildings, cars, trees, other people, etc. Mobile phone towers have sophisticated systems for detecting your phone, amplifying your signal, handing you off to other towers as you move, and so on. Even when you’re not using the phone, it’s still tracked by the network so that you can receive calls.

The whole mobile phone network is geared towards providing service to people on the ground.

If you and your phone are flying over a city, the signal from your phone isn’t blocked by buildings, cars, trees, or anything else. Just like you can see further when you’re up higher, your phone signal can also travel further. In theory, you could be tracked by hundreds of towers at once as you zoom by at six hundred miles per hour, causing a fair amount of confusion in the network.

That’s the theory, anyway. The FCC and FAA haven’t found conclusive evidence that mobile phones in airplanes can significantly interfere with their systems or ground communications. Never the less, both the FCC and FAA operate on the principal of “dangerous unless proven otherwise.” It’s not an unreasonable position to take, given what’s at stake.

Other than mobile phones, airlines have a fair amount of flexibility about what electronic devices they allow when the plane is above 10,000 feet. For example, wireless Internet access has become available on many airplanes. I’ve video conferenced with my wife while she was at 30,000 feet over the Atlantic. How cool is that?

So what about under 10,000 feet? What’s special about taking off and landing?

Taking off and landing are the two most dangerous things that a plane does. Bird strikes, collisions with other planes, sudden gusts of wind, engine and landing gear malfunctions — the list of bad things that can happen when you’re near the ground is huge. Banning electronic devices during that critical time removes one of the potential risks from the situation.

The other reason is that if something does go wrong, you’ll need to get off the plane in a hurry. Your flight crew’s biggest responsibility in an emergency is to get everyone off of a plane within 90 seconds. Statistically speaking, after 90 seconds, the game is over. That’s not a lot of time to evacuate a large airplane, so it’s critical to remove obstacles and distractions— hence the litany of seat backs, tray tables, properly stowed baggage … and turning off electronics.

So what happens if you fail to shut down your portable electronic device during landing or takeoff?

You probably won’t crash the plane, but your flight attendants won’t be pleased. It’s best to follow the instructions, if only for the sake of civility!

"If you’re not part of the solution, you’re part of the precipitate. — Henry J...."

Thu, 12 Aug 2010 10:00:00 -0700

“If you’re not part of the solution, you’re part of the precipitate. — Henry J. Tillman”

Are coffee grounds good for the soil in your garden/yard? If so, why?

Wed, 11 Aug 2010 16:54:00 -0700

Yes, coffee grounds are fantastic for garden soil or compost. They’re rich in nitrogen, act as a pH buffer (most of the acidity is removed during brewing), and retain water nicely. Because coffee grounds are already ground up, they’re easy to mix into your soil or compost, and more easily broken down by worms, bacteria, etc.

All that said, plants need a balanced diet. Leftover coffee grounds are a terrific addition to your soil, but you probably won’t do well potting a plant in pure coffee grounds.

What is the place of religion in science?

Wed, 11 Aug 2010 15:46:00 -0700

I will admit some trepidation in attempting to answer this question, because any time you throw “science” and “religion” into a discussion, it tends to get fairly heated.

That said, I think it’s a very important discussion.

So, here are my two cents.

We have an essential desire to know how the universe works. We’re pushed and pulled towards understanding the world around us, because it gives us peace of mind and the ability to make reasonable decisions about what we do with our lives.

The fundamental goal of science and religion is to address that desire, and I think people who are genuinely interested in learning about the world and humanity will study both.

That said, unquestioning certainty is the biggest thing that keeps us from understanding. The unquestionable idea is both poisonous and tenuous — poisonous in that it isolates people and sets them against each other, and tenuous in that all theories and beliefs are eventually tested. When a theory holds true, it is no longer unquestioned — if it is not, it gets discarded for something better.

This pattern has has repeated itself for as long as we’ve been around: The landscape of human history is littered with the remains of failed ideas. It takes time, sometimes thousands of years, but when we’re empowered to ask questions, we start to see and move beyond our failed ideas.

I think it’s reasonable to believe that this trend will continue.

The “battle” between religion and science is short sighted. Extraordinary scientific progress has come from deeply religious cultures, and it bothers me to see so much time and energy wasted on polarizing questions that can only be advanced by thoughtful, attentive, and reasonable discussion.

The place of religion in science (and science in religion) is to work towards discovering the truth about who we are, where we are, and why we’re here. The goal is to improve ourselves and the world around us. The goal is to lead fulfilled lives, to have adventures, to play games, to connect with others, to learn — to do the things that we love to do.

That’s my theory, anyway.

You’re welcome to ask why!

Incredible Photo of the Tarantula Nebula

Wed, 11 Aug 2010 11:28:00 -0700

Incredible Photo of the Tarantula Nebula:

A few days ago I answered a question about megapixels. If you’re interested in exploring an extraordinary gigapixel-sized image of the Tarantula Nebula, you have to check this out!

"Equipped with his five senses, man explores the universe around him and calls the adventure Science...."

Wed, 11 Aug 2010 10:00:00 -0700

“Equipped with his five senses, man explores the universe around him and calls the adventure Science. — Edwin Hubble”

How cool are non-newtonian fluids?

Tue, 10 Aug 2010 20:54:00 -0700

I think you asked this just to see some awesome videos.

An explanation will follow!

… and who doesn’t like Ellen?

Alright, alright, that’s good enough. You get the idea — it’s a vaguely creepy goo, and you can make in your own kitchen!

Simply stated, a fluid is non-newtonian if it’s viscosity changes under stress (like a punch, or vibration from a speaker).

Cornstarch is a particularly fun and cheap demonstration, and silly putty does the same thing.

But why?

In “normal” newtonian fluids, when you put pressure on the fluid the molecules can slip past each other at a rate that’s constant with the pressure. When a non-newtonian fluid is put under pressure, the molecules have trouble flowing past each other and lock up. It requires a certain density of molecules to work, otherwise they can’t get close enough to connect.

You can experiment on your own: take a bowl half full of warm water, and slowly add cornstarch. It’ll slowly thicken up, but it doesn’t start acting strange until cornstarch makes up about 1/3 of the volume of the mixture. The effect will gradually increase, and when cornstarch makes up about 2/3rds of the mixture, you’ll have a pretty fantastic substance to play with!