Sciencemadness Discussion Board

Something bothers me for so long

Pumukli - 24-5-2016 at 10:10

Eons ago my physics teacher -who knew that I was interested in chemistry- tried mocking me and pointed out a "discrepancy" in a fundamental law that I could not explain to him. And I still can't if I'm honest. :-)

Here it goes:

Imagine that you have a metal (steel) spring.
Now imagine that you compress this spring and with the help of something appropriate (plastic thread, fishing line, etc.) fix this spring in that position. (Essentially you accumulated some mechanical energy at this point.)
Now put this theoretical cocked-up spring into a bowl of acid which would dissolve the metal. Hydrogen evolves, the solution becomes a bit warmer, usual stuff.

The question is:
What happened to the stored mechanical energy? Something SHOULD HAVE HAPPENED if the law of conservation of energy applies, shouldn't it?

I bet that this question bothered some brighter minds since Newton and probably some SM members even know the answer too! Please enlighten me!

myristicinaldehyde - 24-5-2016 at 10:13

Well, if the destruction of the spring is uneven, it would bend and release its energy at that point. If the metal dissolves evenly, the tension would rip the weakened metal, and releacmebergy there. I think.

aga - 24-5-2016 at 11:37

Similar, but more fun : make the world's strongest magnet that can crush a man's had flat against a steel door.

Dissolve the magnet.

Where did all that potential Force go ?

phlogiston - 24-5-2016 at 11:43

The stored energy is released as a small amount of additional heat as the metal dissolves. On the atomic level, the bonds between the iron atoms are slightly more strained than in their non-bent lowest energy state. The energy in the bonds is released as heat as the bonds between the iron atoms are broken, the iron is oxidized and dissolves.

aga - 24-5-2016 at 13:18

Close, but no banananana

myristicinaldehyde - 24-5-2016 at 14:14

Quote: Originally posted by aga  
Close, but no banananana

Banananana or bananananana? :P

aga - 24-5-2016 at 14:22

Googled it.

bananananananananannananana.

Ref: Terry Pratchet.
"Banana is a word you can start spelling, yet stopping is optional."

(or something like that)

WGTR - 24-5-2016 at 15:02

An "off the top of my head" guess:

Attachment: v63-068.pdf (129kB)
This file has been downloaded 311 times

In other words, mechanical energy is converted to chemical/electrical energy.

The Volatile Chemist - 24-5-2016 at 15:38

Quote: Originally posted by aga  
Googled it.

bananananananananannananana.

Ref: Terry Pratchet.
"Banana is a word you can start spelling, yet stopping is optional."

(or something like that)

Wait, is this a thing...? :(

So, he was mocking you because he though chemistry was flawed? Heh. Physics has some of the most established laws and theories, but it also is one of the least established fields in general. Also, explain the difference in force carriers between the four fundamental forces...
Chemistry, on the other hand, is one of the most established - if you take chemistry as being able to say what happens when you mix any x with any y with any z :) Besides, finding a topic to do a thesis on that's legitimately new is probably the hardest in chemistry (although really you could just mix some exotic inorganic reagent with an organophosphorus or boron compound and record what happens...). Biology looks like a fun new field, chemistry is a fun, well established field, and physics is...terrible, in my eyes...

MrHomeScientist - 25-5-2016 at 05:28

How is physics "one of the least established" fields? You don't trust Newton? Don't believe the LHC and the mountain of quantum theory behind it?

blogfast25 - 25-5-2016 at 06:08

Quote: Originally posted by MrHomeScientist  
How is physics "one of the least established" fields? You don't trust Newton? Don't believe the LHC and the mountain of quantum theory behind it?


Yes, I REALLY want to know that too! :D

The Volatile Chemist - 25-5-2016 at 18:28

Quote: Originally posted by MrHomeScientist  
How is physics "one of the least established" fields? You don't trust Newton? Don't believe the LHC and the mountain of quantum theory behind it?


I know, I know....talking to two very educated physics-people here :)

The cutting-edge of physics is very big. I guess that's what I meant to say. Or at least what's more correct. Whenever you see a challenge come up in chemistry - boom - solved. Maybe 10 years, but still. Cubans - done. That crazy tricyanomethane stuff? Done. However, Physics-people (sorry, my spelling for some words is embarrassingly terrible...) have been going after the Higgs boson for a while. Same with string theory, etc. I'll admit, I say this uneducatedly.

Also, chemistry research is often on the small scale with regards to theory. No big new theories in chemistry waiting to be solved. However, Physics, at least on the small scale stuff, is very new. Though perhaps I'm calling particle physics physics in general. I don't suppose there are too many more gravity theories to be made...

UC235 - 25-5-2016 at 20:16

The real questions in chemistry, like how to actually model bonding, electron interactions, and what orbitals look like are inherently physics-related. We have models that can be used to describe and predict certain things, but they are not continuous. There is not yet a unifying theory for chem.

Isolating an unstable compound is hardly the same as predicting a part of the standard model. It's more like engineering than pure science, as is most of organic and inorganic chemistry.