Pick Peat!

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)

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.

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!