LEDs and Water Hazards

LEDs and Water Hazards

If you”ve read my last two columns, you may rightfully assume

that I”ve become obsessed with the subject of water since arriving

on Marco Island. This obsession was only heightened following

a round of golf at the water hazard-infested Vanderbilt Country

Club course in Naples. I shot my best round of the year but

various and sundry ponds and lakes gobbled up a half dozen

brand new golf balls. (Ok, it was my only round this year and

my golf was atrocious! And I thank my nephew Bob and his

friends Jerry and Gary for putting up with my performance.)

With all the water in evidence in these parts, it”s hard to believe

that Florida is experiencing a severe drought. Today”s front page

of the Marco Daily News has a large color photo of a parched

and cracked Everglades and the lead story tells of the acting

police chief of Naples going out on pre-dawn patrols looking for

criminals. Not your rapists or burglars, but water scofflaws

watering lawns, washing cars or the like.

The nationwide consumption of drinkable water in the U.S.

averages around 150 gallons a day per person. Here on Marco

the figure is 310 and in Naples it”s 350 gallons a day, over twice

the national average. Key culprits are the lawn and landscape

waterers, notably the many golf courses in the area. It seems that

only recently is serious consideration being given to the use of

“gray”, recycled wastewater. This appears to be one of the rare

areas where less-developed countries have shown the way. Last

week, we talked about Namibia”s use of gray water for various

purposes, even at times for a substantial fraction of the drinking

water in Namibia”s capital city.

Another water-related problem of concern here relates to my

favorite dish here on Marco, the fresh grouper sandwich. I”ve

often wondered, in view of the popularity of this item, as to

whether the grouper wasn”t being overfished. Sure enough, the

same newspaper has a story stating that a month-long ban on

grouper fishing in local waters has just been put into effect. This

is the peak of the spawning season; said spawning apparently

takes place in the coastal waters since the ban only extends some

50 miles into the Gulf of Mexico, according to a fishing boat

captain I queried at a local restaurant while I was munching on a

grouper sandwich. I felt comfortable eating it after being assured

that the seafood content was gathered in a legal manner.

After putting aside the newspaper, I decided to finish the

February Scientific American, which provided much of the

material for last week”s column. I was pleasantly surprised to

find an article titled “In Pursuit of the Ultimate Lamp” co-

authored by a former Bell Labs colleague, Nick Holonyak. I

may have mentioned Nick in an earlier article on light emitting

diodes (LEDs). But he”s one of the good guys and his history is

worth repeating. When John Bardeen, one of the three inventors

of the transistor, left Bell Labs, he became a professor at the

University of Illinois, where his work on superconductivity led to

his second Nobel Prize (his first being for the transistor).

Holonyak was Bardeen”s first Ph.D. student at Illinois. Nick

came to Bell Labs but, like Bardeen, left to return to Illinois as a

professor. Back at Bell Labs, we worked on gallium phosphide

LEDs and were ecstatic when we got them bright enough to put

in the pushbuttons of the Princess phones used in the old Bell

System (“Ma Bell” has been dead now for some 17 years).

However, at Illinois Nick was smarter and added arsenic to the

gallium phosphide. His gallium arsenide phosphide LEDs paved

the way to the superbright LEDs of today. For his LED work,

Nick has received a number of awards, the most prestigious

being the Japan Prize, which is accompanied by a substantial

bunch of dollars. Holonyak”s co-authors, George Craford and

Frederick Kish, are no slouches either. I knew George when he

worked for Monsanto and he is credited with making the first

yellow LED. He”s now chief technology officer for LumiLeds

Lighting, a company formed jointly by Agilent Technologies and

Philips. Kish is a manager at Agilent Technologies and was

involved in developing the high brightness LEDs you see ahead

of you in automobile stoplights or in traffic lights. Both these

fellows were students in Holonyak”s lab at Illinois. Bardeen,

now deceased, must have been quite proud of his academic

children and grandchildren.

The article shows a picture of what is described as the world”s

largest video screen. The screen covers over 10,000 square feet

and employs over 18 million LEDs! Fittingly enough for readers

of stocksandnews.com, this screen is the 8-story tall NASDAQ

billboard on Times Square in New York. In an earlier column, I

discussed the projected use of LEDs to change the color of light

in a room to match your particular mood or desire. This is

accomplished by using lamps containing LEDs of different

colors and adjusting the brightness of each to get the particular

color. A cool application of this approach was the Metropolitan

Museum of Art”s lighting of an exhibit of the Beatles” Sgt. Pepper

costumes. The literal coolness of the LED lighting also has the

added benefit of not heating up the fabrics, minimizing the

deterioration that could result from hot incandescent lamps.

If you think that I”ve strayed from the subject of water, let me tell

you what really caught my attention in the article. If you”ve

watched any recent TV shows dealing with underwater research,

you”ve probably seen segments dealing with the attachment of

cameras to whales, sharks or seals. The object of using these so-

called “Crittercams” is, of course, to record what really goes on

down in the depths of the seas. The Crittercam allows us to get a

unique view from the standpoint of the marine animal itself.

The article refers to the work of marine biologist Greg Marshall,

who”s associated with National Geographic Television. One of

his prime concerns is that sperm whales, for example, tend to

meander around the ocean at depths down to several thousand

feet below the surface. At such depths there”s precious little

light, to say the least. Not only that, but the pressures are

tremendous and would crush your trusty 35 mm camera. From

the lighting standpoint, LEDs are ideal compared to those

powerful floodlights you might think of first. The LEDs are tiny

and require much less power. Their small size and low power

means you can cram into your Crittercam all kinds of electronics

to record data such as time, temperature, speed, direction, depth,

sounds, etc.

All this is housed in a pressure-resistant torpedo-shaped metal

cylinder and some plucky guy or gal has the responsibility of

attaching it to the whale. But there”s still a problem. Greg

Marshall is finicky and he wants to record the natural behavior of

the whale and its surroundings. Most underwater projects of this

nature involve using a bright light to illuminate the scene. But

this means both the whale and the surrounding marine life will

sense the light and will probably react differently from their

normal behavior in the blackness of the underwater environment.

Here”s where the LEDs shine again. By the proper choice of

material to make the LEDs, you can generate infrared light,

which is invisible to marine life as well as to us humans. By

making the camera one of those night-vision types such as the

ones that film those nighttime scenes we occasionally see on TV,

Marshall can accomplish his goal of catching the animals doing

what comes naturally. His Crittercam has already revealed

hitherto unknown behaviors such as bubble-blowing seals and

the “singing” they do during courtship. The Scientific American

editors opined that the chase scene resulting from a Crittercam

attached to a shark was just as exciting as a spy movie. In case

you”re wondering how the film is retrieved, there”s a time release

mechanism that releases the Crittercam from its harness and it

floats to the surface. I presume there”s a transmitter of some sort

that allows its location to be determined for its retrieval.

After finishing this article, I found a relevant item in the March

2001 Discover magazine. I”ve mentioned previously my work on

lithium batteries. In particular, I was a co-inventor of a cathode

material, niobium selenide, and at Bell Labs we made a great AA

lithium cell using it. As with the LEDs and Nick, John

Goodenough, now at the University of Texas, was smarter. I met

John at a NATO-sponsored course on microbatteries in Sicily,

where we were both lecturers in the course. He invented a

cathode material known as lithium cobalt oxide, with twice the

voltage of our material. Sony picked it up and it”s the cathode

material used in most of today”s lithium-ion batteries that power

your laptops or cellular telephones. The Discover item reported

that Goodenough, again like Holonyak, has won the Japan Prize

and the accompanying $450,000!

Oh well, I”m going out to buy another bunch of golf balls. My

nephew has indicated we”re going to play another water-infested

course. At least in golf I don”t have to worry that I”ll ever come

close to missing out on any big time prizes!

Allen F. Bortrum