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Why are perpetual motion machines so silly?
How does this relate to the big environmental push we have been seeing lately?
Find out by listening to the CultureCast above (by pressing the little blue play botton), or by clicking through and checking out the transcript and further sources.
First Law of Thermodynamics: Energy cannot be destroyed or created (CultureCast #027)
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Transcript
Hey CultureCrew, this is Joshua Hwang again, dropping another 90 Seconds to Culture podcast.
(The) First Law of Thermodynamics: Energy cannot be destroyed or created
In this new environmental age, people demand more efficient products to save the world. Even things as small as light bulbs need to be more efficient. But what does it mean for light bulbs to be more efficient? Where is that energy going?
The first law of thermodynamics states that energy neither be created nor destroyed. While it may be converted from one form to another, the total amount of energy remains the same.
In the case of our environmentally unfriendly incandescent light bulb, not all of the electrical energy is being converted to light energy, in some cases, more than 90% of it is being converted to heat energy. Still though the amount of energy inputted to the light bulb is the same as the total energy outputted by the light bulb. Again this is because energy cannot be created or destroyed, just converted between forms. This is the first law of thermodynamics.
In a very special case, energy can be converted to matter, which is the topic of one of the very first CultureCasts: E=mc2.
The first law of thermodynamics is important to remember as well, because of the idea of perpetual motion machines. These machines hope to produce energy from nothing. This however, is not possible due to the First Law of Thermodynamics, and now you know that this means energy cannot neither be destroyed nor created.
Sources / Further Reading:
90 Seconds To Culture: E=mc^2 - A very special form of the first law of thermodynamics.
Wikipedia: First law of thermodynamics
Wikipedia: Perpetual Motion
BBC NEWS: Light bulbs not such a bright idea
[tags]thermodynamics, physics, perpetual motional, environmentalism, energy, efficiency, podcast, culture[/tags]
(image from PakyuZ via flickr)
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