Tuesday, May 6, 2008

Does the Sun Power Everything?

Touted as the cleanest and only cost-free energy source, finding ways of getting our energy needs from the Sun can no longer be ignored. But is it stretching the truth a bit when we say that the sun powers everything around us?

By: Vanessa Uy

Currently it seems like every one is involved in the race to harness the energy that streams down on us from the Sun. Touted as the cleanest renewable energy which sends us light with no monetary costs whatsoever. It seems like harnessing the Sun’s radiant energy is the best thing for us since free money, but shouldn't we know more about our nearest star first before putting all of our energy security eggs in one solar basket?

Some might harbor the notion that the sun is renewable, actually it’s not. The Sun has been slowly dying for 5 billion years. And 5 billion years into the future, it will turn into a red giant star that would kill all forms of life on the Earth’s surface. But given the vast time scales – and we humans have only been around for less than a million years – it’s safe to say that the sun could be considered “renewable”. Who knows that a few centuries from now we could develop technologies that allow us to travel and colonize other Earth-like planets in other star systems, with the same ease as flying to a vacation spot 1,000 miles away like we currently do. Remember folks, our manned space program is there for humanity’s long-term survival. Our civilization could potentially outlive our Sun.
The ancient plants used the Sun’s radiant energy as they grow then later died hundreds of millions of years ago. Their (the plants and the ecosystem supported by it) long dead bodies are where our crude oil and coal comes from, hence the term fossil fuel. A mighty testament on how solar energy is stored and sequestered naturally, and these fossil fuels are still full of that solar energy made by the Sun countless of eons ago. The bad news is we are using it faster that nature can replenish back the supply. So we should find ways to extract power from the Sun directly.

Wind turbines, hydroelectric power, even wave power’s apparent renewable credentials are nothing more than the Sun powering our planetary weather and climactic system. Blowing air around that allows wind turbines to generate electricity. Our Sun heats up the water on the ocean’s surface evaporating it. Then sending water back to the mountains as rain that flows back to the rivers, whose flow is harnessed by hydroelectric plants before the water flows back to the sea, thus the cycle repeats again. Even the waves and sea currents that we are now learning to harness are ultimately powered by the Sun.
The radioactive elements we used to power our nuclear fission power plants can be traced back our Sun’s precursor which is several times its size. Given our current knowledge of Astrophysics, our Sun’s large precursor did not die quietly. It exploded into a supernova which during the several billionths of a second before blowing itself to bits, created of most of our planet’s supply of uranium. And because of this explosion, our Sun was eventually born. Even geothermal power owes its existence to the nuclear alchemy of a supernova explosion because our planet’s internal heat is nothing more than a natural nuclear fission reactor.

Given our current understanding of the Sun’s benefit to us – from the very distant past to the farthest recesses of our distant future – only leaves us with awe. And our current fascination in harnessing this cleanest source of energy that’s relatively free will only increase in quantity and sophistication as time goes on. The pre-Columbian civilizations of the Americas were really on to something when they decided to pay homage to and worship the Sun. The Sun really did make everything possible.

Monday, May 5, 2008

Perpetual Motion Machines Versus the Laws of Thermodynamics

With the skyrocketing costs of fossil fuel derived energy, are power sources modeled after perpetual motion and free energy experiments a viable solution?

By: Vanessa Uy

Visualize this scenario; A young person – assuming already knowledgeable about the workings of electric motors, dynamos, and rechargeable batteries – suddenly gets a “eureka” moment during a tinkering sessions. He or she proposes “What if I connect an electric motor to drive a dynamo to recharge a rechargeable battery which supplies power to the motor, wouldn’t this set up run forever?” Sure enough, the set-up did ran for awhile due to the charge left on the rechargeable battery, but inevitably grinds to a halt. Undaunted by this set back, our young and curious “explorer” devises other set-ups based on perpetual motion and free energy concepts. Like a light bulb surrounded by photovoltaic cells which are wired to power the light bulb – which logically would make the light bulb shine forever. After frequent and fruitless attempts of other similar devices, our young experimenter finally calls it quits.

Assuming our young person is fortunate enough to afford higher education – specifically Physics – he or she will look back at her days of folly undertaking the fool’s errand of the fruitless search of free energy and perpetual motion. Especially after enrolling in a class that focuses on the Laws of Thermodynamics the bane of perpetual motion and free energy’s existence. But are these laws really stifling our attempts to gain independence from money-hungry – not to mention environmentally polluting - multi-national energy conglomerates, or is it like what the great scientist and visionary R. Buckminster Fuller used to say: “There is no shortage of energy, only a shortage of imagination.” Before proceeding further, lets examine the three Laws of Thermodynamics and how they serve as the proverbial “glass ceiling” when it comes to pursuing our dreams of free energy.

The First Law of Thermodynamics revolves around this concept of conservation of energy, which many see as an axiom without proof. It states that energy cannot be created or destroyed; it can only be transformed from one form to another like work or heat. Also that work input should equal to work output – or unity in 100% efficient engine. Since 100% efficient engines don’t exist, power input is always less than power output. In short you can’t get something from nothing. So overunity machines, machines whose power output is greater that the power input - violates this law.

But is the First Law really that ironclad? Fortunately there’s a loophole in the first law: If energy can’t be created, can it be recaptured and used over and over. Perhaps the motion, the heat and the light can be converted back into energy to perform the work over again. This assumption lies behind our young experimenter’s first set-up previously discussed, and so does the next set-up discussed previously. The explanation on why our motor-dynamo-rechargeable battery set-up and the light bulb surrounded by photovoltaic cells set-up is due to its violation of the Second Law of Thermodynamics.

The Second Law of Thermodynamics – also termed as the “zeroth” principle of thermodynamics – which states that heat can’t be completely converted (or recycled) completely back to work because some energy is irrecoverable as waste heat. Just as water won’t run uphill naturally or under its own accord, heat won’t run “uphill” by going from a cooler body to a hotter body or environment. It goes only the other way. Physicists’ back in the 19th Century who studied such phenomena labeled it as the “Second Law” only because it is discovered after the first law. The term “zeroth principle” is more apt because The Second Law of Thermodynamics’ overall influence supersedes the first, the laws governing energy and heat flow – or the tendency towards maximum entropy - really is the death knell of perpetual motion machines and to our hopes for getting free energy.

The Third Law of Thermodynamics states that this one-way flow of heat and energy – the tendency towards maximum entropy – never ends. This increased entropy or randomness of a system even extends right down to the atomic level. Even further if you include Max Planck’s principles of one quanta at a time energy flow.

The three Laws of Thermodynamics has even been concisely summarized as: 1) you can’t win – free energy and overunity are a no-no 2) you can’t break even – sorry no perpetual motion; and 3) you can’t get out of this game. Science fiction writer and visionary Arthur C. Clarke said a few years back that the Laws’ of Thermodynamics – especially the zeroth principle – are a good thing. This is so because if everything around us would spontaneously become hotter because heat and energy no longer follow their one-way flow, our planet will slowly warm up to the temperature of the planet Venus. He even added that free energy would be a crime against humanity given the catastrophic outcome.