The study of how the properties of matter arise from its structure at all scales and of how processing can be used to modify those properties (often in pursuit of a specific application).
1
vote
1answer
129 views
Friction between atoms in spring
if i doing experiment on spring-mass system in vaccum,if i pull the to some extent (within elastic limit of spring) & let it go,will the system oscillate indefinitely? (neglect contact frictions ...
23
votes
8answers
8k views
Will a hole cut into a metal disk expand or shrink when the disc is heated?
Suppose you take a metal disc and cut a small, circular hole in the center.
When you heat the whole thing, will the hole's diameter increase or decrease? and why?
19
votes
3answers
551 views
Why wet is dark?
When something gets wet, it usually appears darker. This can be observed with soil, sand, cloth, paper, concrete, bricks ...
What is the reason for this? How does water soaking into the material ...
5
votes
1answer
804 views
Transparency of materials
Is transparency of material has something to do with inter- or intra-molecular bonding? E.g. both graphite and diamond are carbon, but graphite is opaque and diamond transparent.
9
votes
1answer
780 views
Why does paper become transparent when smeared with oil but not (so much) with water?
When I smear oil onto a scrap of paper and rub it in, the paper becomes quite transparent; but when I attempt the same with water it doesn't as much. Why?
6
votes
1answer
917 views
Why are some materials diamagnetic, others paramagnetic, and others ferromagnetic?
Why are some materials diamagnetic, others paramagnetic, and others ferromagnetic?
Or, put another way, which of their atomic properties determines which of the three forms of magnetism (if at all) ...
11
votes
3answers
612 views
Is one way glass possible?
I am not talking about mirrors, just a plain window made of glass like material. Would it be possible to allow light pass only in one direction but not the other?
2
votes
2answers
436 views
Mnemonics to remember various properties of materials
I'm trying to figure out how to remember that
hardness: how resistant it is to deformation
toughness: how resistant it is to brittle failures
stress: force on a surface area
strength: ability to ...
6
votes
1answer
737 views
What is the penetration length of static electric field into conducting metals?
How large is the penetration length for static electric field into good conductors?
I have two versions: (1) few atomic spacings
$$a\sim n_{e}^{-1/3},$$
and (2) Debye length computed by Fermi ...
4
votes
2answers
249 views
How to calculate the highest theoretical artificial hill?
The biggest peak in the world is Mount Everest.
Imagine someone starting to make an artificial hill (like pyramide) from soil (earth).
So, when starting with an 200x200 Km base area, with 45degree ...
4
votes
0answers
775 views
Inflating a balloon (expansion resistance)
I am doing a quick calculation on how to calculate the pressure needed to inflate a perfectly spherical balloon to a certain volume, however I have difficulties with the fact that the balloon (rubber) ...
3
votes
4answers
1k views
Graphene space elevator possible?
I just read this story on MIT working on industrial scale, km^2 sheet production of graphene.
A quick check of Wikipedia on graphene and Wikipedia on space elevator tells me
Measurements have ...
3
votes
3answers
265 views
Why is copper diamagnetic?
Cu has an unpaired electron in 4s, but it is diamagnetic. I thought that it has to be paramagnetic. What am I missing?
3
votes
1answer
206 views
Why does glass break at the line where you score it?
Why does it take such a small incision for the glass to break at that spot? Why is the structural strength of the material influenced by such a small imperfection?
1
vote
1answer
447 views
Best Materials Science Introduction Book?
Why is this here?
Sorry, I know that this isn't the best place to put this however there does not seem to be any other stack exchange specific to this so I thought this would be the best place ...
1
vote
2answers
559 views
Calculate the weight a simple plank can support
I'd like to build a simple desk; just a single plank of wood (or a few side-by-side) with solid supports on each end of the desk. What I'm trying to figure out is how thick a plank I want to use for ...
0
votes
0answers
77 views
Which viscoelastic material that transparent for Infrared light?
I have to work with viscoelastic materials, since I tried to use a silicone polymer (silly putty) which expect to IR transparent properties, however, IR camera shown the black color (means their ...
0
votes
1answer
61 views
What are the Electric and Magnetic Properties of Aluminum Oxynitride?
Is Transparent Aluminum (Aluminum Oxynitride) a good conductor of electricity? Also, is it attracted by a magnet?
