Moon Halo
Perhaps you are someone who has noticed an ominous halo around a full moon on hazy nights of the year. Perhaps you wondered where it came from, that there must be some logical explaination. Or, perhaps, you thought it signaled the coming of the apocalypse. Well, the moon halo is in fact no such doomsday omen, but a perfectly explainable atmospheric phenomenon, and it doesn't just happen with the moon, but with the sun as well.
The moon halo, if you are lucky enough to see it, is a fantastical sight composed of a bright circle in the sky wrapped around the moon. When the conditions are just right, there may even be two halos. The cause of this halo is surprisingly simple. Sunlight, reflected off of the moons surface, is refraced by ice crystals in the atmosphere. On humid nights, when there's some moisture in the air, that moisture forms ice crystals at the higher altitudes where the temperature is cooler. This cooling with rising altitude is another atmostpheric phenomenon. When the sunlight reflected off of the moon travels though hexagonal ice crystals, the resulting rays emerge at 22 degrees from the plane which they entered in. The result is that light is focused at a regular distance all around the moon. A second halo may result from a further angle of refraction. The halo is most spectacular on nights when the moon is full.
Engineering a New Spinal Cord
Tissue engineering is a field at the forefront of modern science and medicine, and engineering a new spinal cord is just one goal its laborers are working towards. While she admits that regrowing a spinal cord is still a long way off, the young professor of Biomedical Engineering at Yale, Erin Lavik, sees her work as contributing to that eventual prospect. The main idea, says Dr. Lavik (http://www.yale.edu/opa/v32.n3/story1.html), is to provide a degradable scaffold for nerve cells to regrow missing parts of the nervous system. She is quick to point out that the age-old misconception about growing living nerve cells is completely fallacious. Not only can nerve cells be grown and survive, but nerve stem cells can form the axons and dendrites characteristic of those in a functioning nervous system.
Dr. Lavik entered her career in biomedical engineering from a career in materials science at MIT. She developed scaffolds of many different qualities, from faster degradation, to tube-like pores, to cubic pores, all from degradable polyesters, similar to those used for degradable sutures. Using scaffolds of many different types, cells can be grown in a given orientation. This is crucial to something like spinal cord repair, which demands that new cells grow and properly meet up with old cells.
The work Dr. Lavik's lab has done in this area is in rats. Rats with lesioned spinal cords, say a small section of spinal cord with one half of it's area excised, are ready subjects for implantation of tissue scaffolds. Adding nerve cells to these scaffolds results in new growth. Dr. Lavik's trials have yielded surprising results. Rats with scaffold implants where spinal cord tissue has been removed are able to regain a remarkable level of mobility in limbs below the area of damage. Rats without the scaffold drag their hind limbs behind them, as they have been immobilized. This is significant, but getting the nerve cells to actually become a new spinal cord is the hard part, and is still a long ways off. The scaffold prevents glial scarring, or accumulation of glial cells at the site of the damage, which might be the reason rats without the implanted scaffolds perform so poorly in physical tests.
Dr. Lavik has also been able to get some vascularization into the scaffold where the new nerve cells grow and this, she says, is crucial to further success because organs without blood cannot survive.
The long term effects of the scaffolds are also not known. In addition, nerve cells have not yet been connected at the ends of the scaffold, where the old and new tissue meet, and this too will be an important step in restoring spinal cord function. But the future looks bright for Dr. Lavik and her team, with much success and no end to further directions for their work. One interesting component of these tissue scaffolds is their ability to deliver drugs to the site of damage in a controlled way. Imagine, a spinal cord injury repaired with a polyester scaffold containing a drug therapy regimen and some nerve stem cells.
Sub Atomic non-Atomic Particles
The world of particle physics is filled with studies utilizing giant equipment to hurl atoms at each other, scientists with big egos (this stuff is filled with Einsteinian theory), and at least a few people with a sense of humor (one adjective used to describe an aspect of certain sub-atomic particles is "flavor"). Muons are one of the many particles physicists know about which are smaller than the smalles atom. The particles most commonly known are protons, neutrons, and electrons. If you ever have any doubts about their charges, just remember that neu-trons are neu-tral, and this clean joke: An atom walks into a bar and says to the bartender, "Hey Joe, I think I lost an electron." The bartender says, "Are you sure?" The atom replies, "I'm positive." i.e. electrons are negative and protons are postive. Electrons are the smalles of the three, but there are other particles which may be smaller.
Muons are smaller than protons or neutrons and are larger than electrons, even though they have the same charge. They are not usually found in atoms, but are rather a particle in a state of decay between other sub-atomic particles. When a muon is in the atom, the atom is much smaller than a normal atom, because its large mass pulls the atomic particles closer together, or they reside in a lower energy state. Muons, with their negative charge also have a counterpart with a positive charge, the antimuon.
Muons enter the Earth's atmosphere and come crashing to the ground at tremendous speed. Cosmic rays, not just a facet of science fiction, produce these and other sub-atomic particles. Muons decay from large pions, created in the upper atmosphere by these rays.
Because these particles are in a constant state of decay, i.e. are losing energy to their environment, any machine that detects them, will detect them at different rates depending on where in the atmosphere the machine is located. This is simply demonstrated by the two muon counters in Switerland. One, at Jungfraujoch, high in the Swiss Alps (often called "The Top of Europe), and another, down in Bern, are counting muons as you read this. Because of its much higher altitude, the Jungfraujoch counter intercepts more atmospheric muons than the Bern counter, by the time the muons have gotten down to Bern, more have decayed, and are no longer muons. This simple demonstration, complete with online counter and webcams is available at http://lheppc17.unibe.ch/~einstein/Einstein03.php. It's Einstein theory simplified.
AM versus FM Radio
It occured to me while making a long trip up to the Canadian border last weekend and listening to a lot of radio, that the difference between AM radio and FM radio must have something to do with the stations I was receiving on my car's radio. I remembered something from a teacher in highschool about those fundamental differences, but my memory of the matter was like swiss cheese.
In simplest terms AM radio is radio which uses amplitude modulation to disseminate information. FM radio uses frequency modulation. This means that both methods use radio waves, comparatively long, slow wavelengths in the electromagnetic spectrum. These are at the opposite end from gamma and x-rays, if you consider that wavelengths in the visual spectrum fall somewhere in the middle.
Amplitude modulation refers to the height of the wave. If you were to draw a wave from an AM tranmission, it would look like the cross-section of an ocean wave, with peaks and valleys, except that some of the peaks would be higher than others. The change in amplitude, peak and valley height and depth, is what translates, with an AM receiver, into a radio broadcast. Its the equivalent of the bumps on a record. Tiny bumps in the vinyl grooves of a record are interpreted by the needle and arm on your record player to produce different pitches. An infinite combination of pitches is possible, and so long as we can hear them, any pitch in the audible range can be heard. Voila, a radio broadcast.
Frequency modulation alters the radio wave in the opposite way to produce a radio broadcast. Frequency refers to the number of peaks and valleys in the wave occur within a given period of time. FM radio uses a carrier frequency, which is actually a range of frequencies, and this range and the allocation of frequencies to different stations varries by country. The carrier frequency is overlayed with signal, i.e. what you want to hear, and the signal changes the frequency of the carrier to make larger or smaller gaps between peaks and valleys in the wave. These gaps correspond to the bumps in the grove of the record, same idea as AM radio, just the opposite implementation.
Interestingly, AM radio is generally of lower sound quality, as smaller changes in the amplitude tend to be lost as noise, and therefore AM radio is usually only used for talk radio broadcasts. The range of AM radio is different during the day and the night, and this is where it gets really interesting. during the day, AM radio signals reverberate across the surface of the Earth, and follow its contours, this is why AM radio reception may be so poor during the day if you are a long way from the source. Distortions in the Earth's surface, i.e. a mountain range, will impede the progress of the radio signal to your device. At night however, changes in the atmostphere which occur when the sun's rays are absent, allow AM radio to travel higher in the air, effectively carrying the AM signal farther from its source, over obstructions. This phenomenon applies to the more commonly used medium and short wave AM signals.
FM radio is clearer over longer distances from its source because its signal is transmitted using only changes in frequency. What this means is that the height of the FM waves is always the same, and only their spacing changes. If you get an FM signal during the day, it will be the same signal you get at night.
The energy of radio signals is conserved along the lines of the law of conservation of energy though, and no radio signal is infinite, as the power it is given at its source will dissipate the farther you are from that source. Increasing the power of a signal though is simply a matter of turning up the juice and pumping more electricity in. This is why stations with a larger budget have better reception, they can afford a higher energy bill.
Radio may also be transmitted in stereo, that means that two different parts of the broadcast may come out of two different speakers, adding a spatial demention to the sound you hear. This is an even more complicated topic however, and one who's explanation belongs to another time.
What About Sourdough?
In my recent explorations of my new home, which was not entirely devoid of remnants from the former tenants, I came across a bread maker in one of the top shelves of the kitchen. As I have been determined to become a do-it-yourself bread maker for some time now, the bread maker was the perfect excuse to get a start on that, at least half-assedly.
One bread type that has always fascinated me for its flavor and origin is sourdough (yogurt does as well, for similar reasons, but that is the stuff for another post). Is the sour flavor from yeast or bacteria alive in the food? How does our body deal with the organisms which cause this inviting tangy flavor? The bread maker also turns out to be a perfect excuse to look to the web and research this topic further, here is what I found:
Sourdough is an old European method for collecting, keeping, and baking with yeast. Yeast occurs in many forms and species all over the place, including, apparently, the air around us. It is also found in the skins of wild grapes, and I imagine organic ones as well, and it is harmless. Yeast can be collected from the air using nothing more than a one-to-one mixture of flour and water in a jar with a cloth over it. If you set this out on your counter, yeast will collect in the mixture and grow and divide. Yeast divides rapidly, and while "budding" the process of dividing is a method of reproduction found in yeast, it is not the only one. In the process of growing and dividing, yeast gives off carbon dioxide and alcohol, hence the bubbles you will see in your yeast collector. Yeast is unique in that it is a single-celled organism that can break down complex carbohydrates, starches, and turn them into sugars for its own metabolism. The breaking down of these sugars is the cause of the CO2 and alcohol.
So what about the sour flavor? Sourdough starter is basically what results from this yeast collector. This mixture must be maintained every two or three days or so after it has started to cultivate the yeast, and this is done by removing a measure of the mixture and replacing it with fresh water/flour mixture for the yeast to consume, grow, and divide in. The mixture will also have a form of bacteria in it, lactobacilli, and this is for two reasons. The first is that bacteria is everywhere, and given the tools, it will grow. The second is that this particular form of bacteria can perform anaerobic respiration, creating energy for its use without oxygen, and the byproduct of this process is lactic acid. Why don't other forms of bacteria grow in this mixture and create a huge unsanitary mess? It turns out that this mixture is a very inhospitable environment for most everything except yeast and this bacteria, provided you provide fresh flour/water to feed it. This inhospitably is due to the alcohol, CO2 and lactic acid given off by the yeast and bacteria. So, not only can you collect yeast for baking bread straight out of the air, but a yeast collector is a terribly convenient arrangement for growing and storing it, without harm to you. Fancy huh?
Sourdough flavor then is the product of alcohol given off by yeast and lactic acid given off by lactobacilli. When used to make bread rise, sourdough starter gives its flavor over to the loaf. Do you taste a hint of sourdough in that ryebread you're eating? That might be because rye flour is often used for the sourdough starter mixture, and then to make rye bread. Whole wheat flour works as well.
Lepidoptera in the News
As an advance notice for all you junkies of the newspaper science section, this coming Tuesday in a major national newspaper there will be a story about lepidoptera, that's butterflies and moths, and the people who collect them. This is an opportunity to plug the research I do and share some information about the growing world of "your own backyard."
Earlier this week a reporter came to my university with Dave Wagner of the University of Connecticut to do a piece about collecting caterpillars, moths, and butterflies. Dave Wagner is an entomologist and has made a career out of collecting, documenting, and protecting hundreds of insect species. His specialty is lepidoptera, and when it comes to this area, he wrote the book, literally. It's called Caterpillars of Eastern North America by Princeton Field Guides, and you couldn't find a better guide to the species you'll come across in this region of the country. He was the ideal person to contact for this newspaper story. He's in touch with my PI (that's primary investigator, or my boss) and invited the reporter and some amateur lepidopterists to come out collecting with my lab group. The main event was a nighttime "black-lighting" where lights, especially black lights or mercury vapor lights, are hung up in the woods and grasslands next to sheets which moths are drawn to in droves. No one is quite sure why this happens, though there are many explanations, but it's the most efficient way to collect the largest number of species in one go.
I don't want to give away any more of the story, I'll just say to look in unnamed newspaper's Tuesday science section on July 4th for more information. If the story doesn't make it in on that day, check back in a week. It's sure to be accompanied by some impressive pictures, or at least one of Dr. Wagner educating our motley crew.
To complement the piece, I've decided to present my own short list of interesting species you can find in your own back yard. Try by checking tree branches and shrubs for caterpillars, or by setting up a white sheet and blacklight somewhere in the wilderness at night for moths. Butterflies can be hunted during the daytime with an insect net and some determination, try fields with tall grasses and wildflowers first. As a reminder, most of the species out there are moths, and the exception to the rule are the butterflies. Many moths are brown or grey, but don't let that deter you, some are spectacular, either as caterpillars or as adult moths, and rival some of the flashier butterflies.
Here's my list:
For Best All Around, the award goes to the Eastern Tiger Swallowtail aka Papilio glaucus.
This is a familiar species to many as a butterfly, but it's got an equally impressive caterpillar or larva. The larva may be found on cherry, tulip tree, ash and other tree species. As a small larva it mimics a bird dropping and as an older larva it's a snake mimic. Those spots on the older green larva aren't it's eyes, but mimicking eye spots. The larva also has osmeteria which it can project out of a spot near its head to scare predators. The adult is magnificent.
For Flashiest Caterpillar, the award goes to the White-Marked Tussock Moth, or Orgyia leucostigma.
Complete with tufts of white or yellow hair, a red head, and a brightly collored body, this caterpillar is distinctive. It is found on just about every woody tree species in the Eastern United States and for much of the summer. The long hairs could cause an allergic reaction, though I haven't had that experience with this particular caterpillar.
For "Don't Touch Me" the award goes to the Saddleback Caterpillar, or Acharia stimulea.
This beauty can be found in many gardens, on apple trees or blueberry bushes, and a host of other plants. The spines at either end are stinging. If I were giving an award for the caterpillar for which you can't tell one end from the other, this guy would get it.
The award for uggliest caterpillar goes to a caterpillar in the same family as the Saddleback, the Monkey Slug or Hag Moth, aka Phobetron pithecium.
At first glance this caterpillar looks like a demonic spider, but on further inspection may actually appear cute and fuzzy. The moth isn't so bad looking either with a black and white pattern. Found on many tree species in the Northeast, Dr. Wagner says that there may be credence to the idea that the caterpillar mimics a shed tarantula skin, if the caterpillar is considered primarily a tropical species (tarantulas are found in the tropics and their coexistence with this caterpillar would be required for a true case of mimicry to occur).
Finally, the award for most stunning moth goes to the Luna Moth, or Actias luna.
This elusive and beautiful species will warm the heart of just about anyone lucky enough to lay eyes upon her. The caterpillar is a nice creature too, but the moth takes the top prize. A newly emerged moth will be a slow flyer and may be found at night with a blacklight. The cocoon of this moth is spun from silk, unlike many other caterpillars which make pupae that are hard and smooth. You should consider yourself lucky to see one of these moths, which may get up to the size of your hand with fingers extended, during your lifetime.
This is of course the shortest of lists, and you should see for yourself all the amazing species of caterpillars, moths, and butterflies out there right near where you live. Find one or find hundreds, you're sure to be entertained and amazed no matter which species you come upon. And, don't forget to check out that article this coming Tuesday.
Pollinators for Hire?
It might never cross your mind that every piece of fruit you eat got to your mouth because of the role a pollinator played somewhere far away and some weeks before. Pollinators are in fact an indispensable part of our nation's, and the world's, agricultural success and may be seriously under-appreciated.
Insects often get a bad wrap, and being a budding student of entomology, it pains me to say that. However, it's true and you'd be hard pressed to find a large group of people who want to cozy up to ants, flies, wasps, or bees over animals of a fuzzier variety. Insects aren't the only animals that pollinate, however, as small rodents and birds do a fair amount of their own. They usually enjoy more fond feelings than do our six-legged friends though, so I'm going to leave them out for now.
Pollination is the crucial step between a flower with male, female, or male and female parts producing their respective gametes, and a fertilized egg which induces a plant to produce fruit. Fruit refers to the housing of a seed which derives from the carpel of the flower, and encompasses most of the vegetables you eat as well like peppers, cucumbers, and yes, tomatoes are a fruit. Plants often have relationships with specific pollinator species or with groups of pollinator species. The pollinator transfers the male gamete-containing pollen to the female floral organs for fertilization of the egg, usually in exchange for a reward, but sometimes through trickery on the plants part. The reward may be nectar or pollen itself, as it is usually high in protein and carbohydrates and a sought after food source.
When one flower gets pollinated, one fruit is produced. Imagine one pollination event, and sometimes just one pollinator for every piece of produce in the fruit and vegetable aisle of your local supermarket. Now imagine how many produce aisles and farm stands there are in your county, your state, or the nation. Imagine how many there are in the world. Now you may begin to have a sense of the scale of this massive effort by pollinators to bring us our healthy, delicious, vitamin rich produce.
Why am I telling you this? It has a lot to do with finances, a lot to do with agricultural practice, and a little bit to do with global warming. Firstly, a recent scientific article did a cost estimate of what it would take to pollinate all the flowers necessary to maintain our current levels of crop production. The number is in the billions. See, many plants aren't able to be pollinated from pollen in the same flower or from the same plant, they need to be out-crossed or receive pollen from a different plant or flower in order to produce fruit. So the organization of such a project would be huge. Then there's the labor and capital costs depending on which method of artificial production you use. Whew. Let me tell you, vanilla bean, from which natural vanilla extract is produced, arises from hand pollination of individual flowers. Now you see why the natural vanilla costs so much more than the artificial flavoring, it's all that labor cost being transferred to you, the consumer!
Pollinators are mostly insects, as I said above, and this is where the story gets grim. Most of the produce you buy is from massive farming operations, and they doubtlessly spray pesticides on everything you eat. Those pesticides not only kill insects indiscriminately in most cases, but they may actually have a stronger negative effect on the pollinator species! In other words, pollinators are slowly being killed off by the very industry that needs them most.
Then there's the global warming story, which I won't go into too much detail for, but suffice to say, global warming results in fewer species, and pollinators aren't excluded.
So, what can you do to save the pollinators? Buy produce that is grown without pesticides. It's pretty much that simple. Also, the next time you see a bee flying around in your yard, try not to squash it, it may just have given you that plum you're eating. Pollinators are an integral part of our world's agricultural system, give them some credit, because without them, we'd probably starve.
Energy Crisis: Part II
The announcement by the Supreme Court today that it would hear arguments in a case concerning carbon dioxide regulation is both important for the environment and will be muddled in political bickering. I won't go into much detail of the law in question, as that is readily available elsewhere. I will say though, that what is essentially a case concerning scientific fact has been hijacked for many years by the automobile, oil, and gas industries. Even in today's online announcement in the New York Times of the case, the article states that some or many scientists regard carbon dioxide as a pollutant and a cause of global warming. This is no small point I make here: every scientist surveyed in a recent science journal regards carbon dioxide as a pollutant and leading factor in global warming. Over nine-hundred scientists were surveyed and the score was 900+ against CO2, 0 for. With each wishy-washy news paper article and television report the public loses sight of the fact that carbon dioxide's effects on the environment are not in dispute in the scientific community.
Interestingly enough I was speaking about this issue at the breakfast table with a friend of mine today and she told me about a public education campaign video she was shown in middle school. In the video, scientists described the benefits increased carbon dioxide would provide the planet Earth. They cited that carbon dioxide is converted by plants, using sunlight, into energy and carbohydrates and this will increase with increase carbon dioxide output resulting in a greener Earth. On this greener Earth we will be more able to feed everyone.
These studies found this to be the case but were fundamentally flawed. The plants used in the experiment were provided with as much water, nutrients, and sunlight as they needed to use all the carbon dioxide pumped into their growth chambers and what the scientists got was what is now called the "carbon dioxide fertilizer effect." This is the effect that given an unlimited amount of resources and an increase in carbon dioxide a plant will grow bigger, faster, and greener. However, in our world, where life plays a zero-sum game, plants cannot cope with added carbon dioxide, or it goes unutilized, and no carbon dioxide fertilizer effect is observed. Instead it is trapped in our atmosphere resulting in the greenhouse effect and global climate change. This has been observed for decades.
In addition to the carbon dioxide fertilizer effect, opponents of regulating carbon dioxide will show pie charts of how much of our atmosphere is made up of carbon dioxide. Carbon dioxide makes up a relatively small percentage of our atmosphere, yes, but due to certain properties of its molecular structure, it acts in a big way which is totally out of proportion with its concentration. In is important to compare carbon dioxide levels now to what they were in the past, not to the other gases in the atmosphere, in order to get an accurate understanding of the current crisis we are living with.
I hope, for my sake and yours, that the Supreme Court rules in favor of EPA regulations of auto and power plant emissions. I do not wish this because of a hatred for those industries, but because I see the problem at hand and I see that we have the power and know-how to solve it. This is not a case of lacking the necessary technology, far from it. We have the technology to curb our carbon emissions now, and research into further cutting our carbon emissions will benefit industry, employees from low-wage workers up to skilled labor and the management, and the health of not only the natural world but of every man, woman and child living in it.
It's all in Your Memes
In the mid-1970s a now much more famous biologist, Richard Dawkins, published his groundbreaking book The Selfish Gene. I don't want to go into much detail about the theme or content of the book as it would require much more space than can be devoted to it in this blog. I will however say, that the main idea is that genes perpetuate themselves, grow, and change using their biological hosts - you and me and every other living thing out there with DNA. That statement actually brings up a point of contention and I would here like to point out that the subjects in Dawkins book are still hotly debated amongst evolutionary biologists. The point is that the very definition of a gene is in question. Whether it is a unit of information, a certain association of nucleic acids, or simply describes the code for how to make a protein, it is a useful term for biology and any uncertainty in its definition should not prevent the important work done in the name of understanding genes.
This post is not about genes however, it's about memes, a term invented by Dawkins in his 1976 publication. A meme, says Dawkins, is a unit of cultural information transmitted from one individual to another in some way. This could be verbally or by way of demonstration. He makes a good point in defining this concept, there is a distinct parallel between the way genes pass from individual to individual and carry specific information which can change, be lost, or expand with time and generations and the way information is disseminated throughout a culture. Memes, as well as being a good metaphor for genes - and biologists love to write metaphors - are of interest to many people and have led to their study, called memetics.
Some examples of memes are a popular song, phrase, or slang word. But memes are also much more integral to our culture and include the beliefs of a religion, aversion to torture by a developed nation, and hope for the future. Some memes are so large, or incorporate so much of what gives a culture its unique characteristics that they are referred to as meme-complexes. The exciting thing to think about with memes is that they may be subject to a form of natural selection and evolution just like our genes. You teach them to your children when you make a rule or punish misbehaver, and they learn them from the way you lead your life too. But you didn't raise your children exactly the same way as your parents raised you and the same goes for how your children will raise their own. The meme has the same origin but is slightly altered with each generation or cultural change. Some memes don't hold up, we have no use for them anymore or find them distasteful, and they go extinct. An important caveat to consider though, those cultural trends or norms you may disagree with aren't easy to change, and real change requires time and repeated selection towards a new idea. It is with memes as it is with genes; the process of change is slow and in many ways is more important and interesting than the end product.
Cultural fads come and go, religions gain steam and go the way of the Middle Ages, clothing styles, song genres, sayings and conventions all come and go and change during their time here on Earth. And all the while they are housed in our minds and executed through our actions. In a way, they inhabit our bodies and tell us how to behave, what to do in a given situation, and establish a social order. In that way, they are just as important or more so as our genes in determining the events in our lives. Can you imagine a high school education without prom? A world where children are raised by a community and don't know who their parents are? How about a society without ownership? All of those things, and so much more, are all in your memes.
Hydroponic Strawberries?
A few weeks ago I was informed of a strawberry grower in a small New Hampshire tourist town growing hydroponic strawberries for the upcoming summer tourist season. Not being terribly familiar with hydroponic growth methods I scoffed at the idea. Although New Hampshire doesn't exactly have a reputation for being outstanding farm country, many strawberry farms do quite well during the summer months. When I inquired further as to why this farm needed to change the way strawberries are cultivated from that used for many many years the answer I got was simple: this way, strawberry pickers won't have to bend over.
So what is hydroponics anyway? To put it simply, hydroponics is the cultivation of plants without the use of soil. Commonly thought of as actually growing plants suspended in water, it more frequently refers to growing plants in a sterile medium, something to suspend the plant and its roots, like plastic beads, while providing everything the plant needs besides air and sunlight in a water solution. Hydroponics is commonly used in tight spaces like apartments, and now apparently, for strawberry patches.
This is not to say that the process is simple. Hydroponic water solutions required, by some accounts, thirteen different additives, mostly chemical fertilizers and nutrients, and you can't always find them easily. Not only that, but chemical fertilizers and commercially produced nutrients are mostly petroleum products, so who makes them? The big oil companies of course. Keep that in mind the next time you buy fertilizer for your house plants or eat just about any crop grown in this country and many others at a large scale, they all use products made and sold by big oil. What you pay at the pump isn't the only purchase you make that lines the pockets of oil execs.
Water and nutrients aren't the only thing plants need either, as any house plant grower will note, but one of the most important things plants need is air. Not only air, but a supply of air to the roots. Why air? Well, air contains oxygen, and oxygen is required for the conversion of carbohydrates into energy. Plants turn the sun's energy and carbon dioxide into carbohydrates, which are transported through the plant to the roots, so that the roots may metabolize those carbohydrates and grow. Roots grow to find more water and nutrients as the visible part of the plant, or shoot, grows larger. So, you may have heard that the most common cause of house plant death is overwatering, and this is why. If you overwater a plant, and its roots are submersed in a water and soil solution, the roots can't breath, and when they can't breath, they can't grow. In addition, this water allows the build up of ethylene, a plant hormone, throughout the plant. Ethylene triggers plant cells to break down, and is the hormone responsible for lovely speckled ripening bananas and other fruits. But, when there's too much ethylene, a plant commits suicide. The leaves turn yellow and drop off.
So, to prevent plants from going suicidal, hydroponic growers must provide either a drying out of the growth medium or aeration so that roots can breath and get oxygen while expelling harmful hormones and toxins. Soil does this for plants naturally by allowing water to drain out through pores between soil particles of different sizes. Soil also provides all of the organic nutrients and fertilizers needed for a plant to grow.
To get back to our hydroponic strawberries, do I think they're worth all the trouble? Well, no. But, I'm sure at least a few tourists with back problems traveling through that small town in New Hampshire will disagree with me. The success of the hydroponic strawberry patch remains to be seen, but I'll pick my strawberries from plants grown in the soil, thank you. And it wouldn't hurt for them to be free of fertilizers and pesticides either; I wouldn't want to eat toxins, and I certainly don't think Joe Oil-Exec needs the cash.
