Entropy: a Science Experiment

[curlytop1222]

as you should know entropy is very real and is as common in the universe as blue-berrys at a fruit market. im testing it for a science fair progect and was wondering if anyone has any ideas. or anything they want me to check?

Thanks guys

[the_peridexis]

you cannot "test entropy" unless you want to kill, maim, or cause something pain. i don't think you want to do that. what you could do is give examples of entropy from all over the world. or worlds, if you prefer. :P there are too many (examples)...ack, you made me brood! but yes, try doing the examples, but if you find any better ideas, give a holler and i'll come running. hope that was helpful!

-peri

[Sean L.]

actually, peri, what you said may not be correct.

Definitially speaking, entropy is the measure of disorganization or degradation in the universe that reduces available energy, or tendency of available energy to dwindle. It is, in a word, chaos - the opposite of order.

Thus 'testing' entropy could be as simple as writing an equation demonstrating there is more entropy as ice melts.

But is that interesting? Not so much. Not like volcanos and masses on cars and stuff. An 'interesting' way to show entropy...may be a lot harder; indeed, killing someone may actually stop entropy, as the metabolic functions that create it also stop.

[alla]

Like Sean has mentioned - Entropy in (at least) a chemical sense can be described as the 'state of randomness' of a system - i.e. gas has more entropy than a solid because the particles aren't fixed.

Check out more advanced level chemistry books for a few experiment ideas, I guess. I may post more in here later, but I have to run.

Alla

[KarateSox]

You learn about entropy in Chemistry and Physics, but only in the really advanced stuff do you actually do anything with it. The symbol for Entropy is S (delta S is used in equations for the change in entropy). An example of entropy are clean room vs. dirty room - the dirty room is in a higher state of disorder, but unfortunately, we don't really have a way of measuring that, it's all relative.
It's been a while since I last learned about entropy in school, so I don't remember what units, if any, are used, but I do remember we rarely did any calculations that involved delta S.

[curlytop1222]

ok guys let me explain in greater detail what is going on.
first off i have read several collage text books on the subject and have tied this in to the second law of thermodynamics. this includes ice melting.
entropy is also the energy not given back by the use of a machine, in a way. a bike is one of the most effecient machines, in that most of the energy put into it is also given back by it, while never reaching 100% of what was put in. part of my plan is to use this to create a machine that is more effecient than a bike and study the energy that is not given back.

also as to what sean said, entropy is chaos, and with out this chaos the world would not be in existance.

also has anyone read "Principia Discordia (or how I Found the Goddess and What I did to Her When i Found Her)" if not i do recomend it as a very good read.

Hail Chaos
Hail Eris

Thanks Guys

also entropy is not studyed often in schools due to its difficulty to measure. it is also a very rare topic at science fairs, thats why i am using it.

Merging two posts - Peter

[alla]

Curly:
entropy is also the energy not given back by the use of a machine, in a way. a bike is one of the most effecient machines, in that most of the energy put into it is also given back by it, while never reaching 100% of what was put in. part of my plan is to use this to create a machine that is more effecient than a bike and study the energy that is not given back.

Don't make it more efficient than a bike - either just use a bike, or make it less efficeint. Don't make it harder for yourself.

Alla

[the_peridexis]

I stand corrected sean. I was still thinking of only one view of entropy--pain and death, basically.

And to culy: The bike idea seems like a really good one, especially if you suceed, but like alla said, don't make it harder for yourself. And since I'm probably the youngest on this topic, my grade hasn't even gotten to to the point of studying entropy, so I can't offer much useful input until I read up on it. Sorry for being a useless topic-clutterer, (:P) good luck curly!

-peri

[curlytop1222]

Update:
i found this in Wiki on bike efficiency:


Performance
Main article: bicycle performance
In both biological and mechanical terms, the bicycle is extraordinarily efficient. In terms of the amount of energy a person must expend to travel a given distance, investigators have calculated it to be the most efficient self-powered means of transportation.[4] From a mechanical viewpoint, up to 99% of the energy delivered by the rider into the pedals is transmitted to the wheels, although the use of gearing mechanisms may reduce this by 10-15%.[5][3] In terms of the ratio of cargo weight a bicycle can carry to total weight, it is also a most efficient means of cargo transportation.

A human being travelling on a bicycle at low to medium speeds of around 10-15 mph (16-24 km/h), using only the energy required to walk, is the most energy-efficient means of transport generally available. Air drag, which increases with the square of speed, requires increasingly higher power outputs relative to speed. A bicycle in which the rider lies in a prone position and which may be covered in an aerodynamic fairing to achieve very low air drag is referred to as a Recumbent bicycle or Human Powered Vehicle.


man i have so serious work ahead of me...
this means i have to get about 99.5% work output to do better than a bike.

[mouse]

wait, so bacicly a bike is the closest to entropy with out wasting (most)energy?well wada know? but becase you all talk in a sophistacated why,i think i may be wrong.MY HEAD HURTS!
~~~mousewashere~~~
"sweet,a plastic cow"
"in other news, i got hit with a flying giraffe today....what?....STOP LAUGHING!"
sweet a snickers!*grabs a muffin*

[Gryphon]

My knowledge about entropy from biology (with the quick aid of dictionary.com 'cuz I've forgotten most of it) is this: entropy is how everything gradually becomes more and more random or heated. ie: whenever a chemical reaction occurs, a large portion of the chemical energy is lost as heat, whereas very little can actually be used. Also, when a reaction occurs, the order of the system decreases (it becomes more random).

:P Sean already explained it. I should've read the entire topic before replying. But anywayy...

Let's put it this way. Equilibrium is bad (from the viewpoint of cells and life), because when a cell reaches the state of equilibrium, it is dead. It can't perform any more metabolic processes, because it doesn't have a flow of molecules and reactions which allow it to do work and function. In a closed system (which a cell would be if suddenly materials couldn't flow in and out of it, for example), everything begins to go towards entropy because the cell does what it does until it doesn't have the resources to perform work anymore.

The "heat death" of the universe is when everything reaches the same temperature, like equilibrium, which is where everything's the same.

nononono, a bike = good. The more energy is used, the closer everything gets to entropy, because some of the energy is released as heat, which is relatively useless. If you use a bike, you get the most out of your energy.

[Wilf]

entropy is also the energy not given back by the use of a machine, in a way. a bike is one of the most effecient machines

nononononon... No! Entropy and energy are two fundamentally different things. Entropy is a measure of the level of disorganisation of a system; energy is the ability to do work (by changing into another form of energy). The energy of a system is fixed and constant; the entropy of a system can and will change (though it tends to increase). Consider:
1) A ball in free fall. Here, gravitaitonal energy is being converetd into kinetic energy, but the entropy of the system remains unchanged (it's just as disorganised, so matter how far it's fallen)
2) A fish tank, with a dividing wall in the middle. On one side of the wall there is water, on the other side ethanol. When you remove the dividing wall, the two liquids will tend to diffuse togther, and you eventually end up with a uniform mixture. Here, the entropy has increased (there are more ways to have the uniform mixture than ways to have the liquids seperated in two), but the energy has remained the same (as shown by the fact the temperatures remain the same)

You could possibly use a variation on the altter as a science fair project... use water with red and blue food dye.... or contrasting colours of glitter. (If they mingle too fast, thicken the water with sugar or corn startch beforehand).

That said, given that the total energy of system doesn't change, what happens to the "the energy not given back by the use of a machine"? The answer is that it ends up as heat. An increase in temperature means the atoms jiggle more, and so have more kinetic energy. So, the energy that doesn't do useful work ends up as random kinetic energy in nearby atoms.

The increase in temperature also means that entropy has increased. The higher the temperature, the more total kinetic energy the atoms have, and the more ways there are to distribute the energy amongst the atoms. (Consider how many ways there are to 0,1,2,3... grapes amonsgt a group of say, 3 people. You'll find in increases rapidly with the number of grapes. The grapes corespond to the energy; the people correspond to the atoms.) The increase in the number of possible arrangements is precisely an increase in entropy.

Now, I've either pitched this info way higher than you need (in the UK, thermodynamics is on only some age 16-18 physics courses, so you might not meet it until 1st year of a physics degree), or I've left you with a lot of questions...

[What\'s up, doc?]

Wow!! Your explanation really helped a lot, Wilf. Luckily I didn't try to read it anywhere else. They're too confusing

Thanks lots!!

[mouse]

Now my head really hurts...