Pumukli
National Hazard
Posts: 705
Registered: 2-3-2014
Location: EU
Member Is Offline
Mood: No Mood
|
|
Something bothers me for so long
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
Hazard to Others
Posts: 166
Registered: 23-4-2016
Location: .͐͌ ͛҉̻̫̰̻̖E̮ͮ̐́̚ ̢̗̅̉ͩ͂̒̌.̯̻̺̯̀̎͂̄ͩ̚
Member Is Offline
Mood: сорок пять
|
|
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
Forum Drunkard
Posts: 7030
Registered: 25-3-2014
Member Is Offline
|
|
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
International Hazard
Posts: 1379
Registered: 26-4-2008
Location: Neon Thorium Erbium Lanthanum Neodymium Sulphur
Member Is Offline
Mood: pyrophoric
|
|
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.
-----
"If a rocket goes up, who cares where it comes down, that's not my concern said Wernher von Braun" - Tom Lehrer |
|
|
aga
Forum Drunkard
Posts: 7030
Registered: 25-3-2014
Member Is Offline
|
|
Close, but no banananana
|
|
|
myristicinaldehyde
Hazard to Others
Posts: 166
Registered: 23-4-2016
Location: .͐͌ ͛҉̻̫̰̻̖E̮ͮ̐́̚ ̢̗̅̉ͩ͂̒̌.̯̻̺̯̀̎͂̄ͩ̚
Member Is Offline
Mood: сорок пять
|
|
Banananana or bananananana? 
|
|
|
aga
Forum Drunkard
Posts: 7030
Registered: 25-3-2014
Member Is Offline
|
|
Googled it.
bananananananananannananana.
Ref: Terry Pratchet.
"Banana is a word you can start spelling, yet stopping is optional."
(or something like that)
|
|
|
WGTR
National Hazard
Posts: 971
Registered: 29-9-2013
Location: Online
Member Is Offline
Mood: Outline
|
|
An "off the top of my head" guess:
Attachment: v63-068.pdf (129kB)
This file has been downloaded 348 times
In other words, mechanical energy is converted to chemical/electrical energy.
|
|
|
The Volatile Chemist
International Hazard
Posts: 1981
Registered: 22-3-2014
Location: 'Stil' in the lab...
Member Is Offline
Mood: Copious
|
|
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
International Hazard
Posts: 1806
Registered: 24-10-2010
Location: Flerovium
Member Is Offline
Mood: No Mood
|
|
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
International Hazard
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
| 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! 
|
|
|
The Volatile Chemist
International Hazard
Posts: 1981
Registered: 22-3-2014
Location: 'Stil' in the lab...
Member Is Offline
Mood: Copious
|
|
| 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
National Hazard
Posts: 565
Registered: 28-12-2014
Member Is Offline
Mood: No Mood
|
|
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.
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
