Off Topic — HabitableZone

Off Topic » in reply to Biofuels

re: Biofuels

Whatever does "run the Universe" (whatever that means), Techy hasn't a clue what it is. He has the same access to information that I, or anyone else does. And nobody knows, so he doesn't either. His gibberish posts lead me to believe he knows absolutely no science, or he is deliberately disguising what he does know and writing giibberish so he can ridicule people like you and Jody. This is the same guy that had the audacity to write in an earlier post:

"Anyone who exploits others ignorance, for either their own amusement, or too "teach them a lesson" is pretty much in the toilet ethics wise."

If you want a real answer to that question, you need to break it down into parts:

1) What drives the expansion of the Universe? The initial Big Bang created a great explosion and the overall expansion we see today is a relic of that event. Obviously, this is not very well undersood by anyone, least of all, Techy.

2) What creates the light and heat and energy we see in the universe? It originates in the cores of stars, where locally, gravity forces atoms to fuse together in a thermonuclear reaction, giving off heat and light and radiation.

3)What forces these atoms to compress together and undergo this reaction? Gravitational energy. In fact, since gravity is the attraction of matter to other matter, as long as matter is dispersed, energy is created as heat as the matter is compressed together under its own weight. You can say that all energy is the result of matter falling into other matter, creating heat through friction, so gravity is now forcing the universe to pay back all the energy it borrowed from the original big bang explosion and dispersion. The thermonuclear energy created in stars by fusion which I mention earlier releases some of the energy the big bang put into the atoms of matter at the beginning of it all.

What you have to keep in mind is that energy has a very strict and scientific definition, it isn't at all what our English usage of the word hints at. We throw the word around very loosely in our speech, and sometimes we substitute totally different words that mean completely different things for it, like power, force, momentum. "Energy" has a very strict scientific definition that can be expressed mathematically in a variety of ways, and it has certain properties and behavior which we have learned through experience, experiment and observation. We haven't made this up, it has been learned by a lot of smart people working very hard for a long time.

It won't help much if you don't know the science that backs it up, but here are some of the definitions of energy. They all mean the same thing but they are formulated in different terms so they can be used to work out differnt types of problems. Energy is:

the ability to do work
force times distance (or more precisely, using calculus)
the integral of a force across a distance
mass times the speed of light squared
photon frequency times Planck's Constant
one half the value of a mass times its velocity squared
the time rate of change, (or derivative) of momentum
power multiplied by time

As you can see, there are other terms you have to define before you start defining what energy is and there are many others. The point I am trying to make is that a question like "What runs the universe" is really meaningless unless you have some grasp of those definitions (and math) and the words that make them up. It's like trying to explain a symphony to someone deaf from birth, or a painting to someone blind from birth. You just get bogged down in words that don't mean anything

I'll give you something to start off with. There are four fundamental definitions you have to understand before you can define energy: mass, distance, time, and electric charge. The latter we can forget for the time being since we aren't planning to do any problems involving electricity or magnetism. Consider instead the other three.

Mass is measured in kilograms, distance in meters, and time in seconds.
We all have a pretty instinctive knowledge of these three. From these we can create other, more complex definitions:

velocity = distance divided by time.
Energy = 1/2 times mass times velocity times velocity.
Power = energy divided by time.

That last definition states that a kilogram mass (about two pounds) traveling through space at a meter (about 3 feet) per second is able to do a Joule's worth of work. A Joule (named in honor of Monsieur Joule) is the name we give to that much energy. One Joule of work per second is a power of one Watt. (That's the name we give to units of power, and it was named in honor of Mr Watt).

Why do we go through all this trouble? Because it allows us to talk about physics so it makes sense in terms of measurable and explainable quantities that can be compared meaningfully. So for example, a 100 Watt light bulb consumes every second as much energy as you would get from a hundred 2 pound bricks flying through the air at three feet per second.

That light bulb uses up energy that had to come from burning fossil fuel that was created in ancient forests or seas by plants nourished by sunlight created in the interior of our star by hydrogen atoms fusing under the pressure of their mutual gravitational attraction to release energy placed there during the initial creation of the universe. Energy can't be destroyed, but it can be dispersed and diluted so it is no longer recoverable for useful purposes. So turn off that light when you don't need it.

Log in or register to post.

The whole thread (43 posts)