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).
3
votes
1answer
268 views
Transparency of solids using bandgaps and relation to conduction and valence bands
I think I understand how a solid can appear transparent as long as the energy of the photons travelling through it are not absorbed in the material's bandgap. But how does this band gap relate to ...
3
votes
2answers
57 views
Can a minimum ultimate tensile strength (UTS) for an asteroid be established based on its diameter and rotation?
I found it fascinating that many asteroids rotate with a period of just seconds. For this fast of a rotation on this size of object, I thought that would actually cause significant acceleration on the ...
3
votes
1answer
97 views
What ring weave disposition should be the most resistant against stabbing and/or how to determine it
In a website that I am studying so I can build a Chain Mail, I have found a page featuring a lot of different Ring Weaves to build them.
I want to determine which one is the best to provide ...
2
votes
3answers
192 views
Material resistency to lasers beam
Keeping the average power constant, why some materials are more eager to be damaged by pulsed laser with respect of C.W. lasers, or viceversa?
When i talk about pulsed lasers i think for examples of ...
2
votes
1answer
186 views
Why magnetic monopole found in spin ice don't modify the Maxwell's Equations?
Magnetic monopole predicted by Dirac nearly a century ago was found in spin ice as quasi-particle(2). My question is Why magnetic monopole found in spin ice don't modify the Maxwell's Equations? (I ...
2
votes
2answers
198 views
Is there a simple approximation to calculate the index of refraction of water?
A very rough approximation from first principles, from the elementary charge and hbar, would suffice. But is there such an approximation at all?
(Alternatively, if water is too difficult: is there ...
2
votes
2answers
948 views
Will the hole on a metal disc expand or contract upon heating? [duplicate]
Possible Duplicate:
Will a hole cut into a metal disk expand or shrink when the disc is heated?
The metal disc of diameter D1 has a hole in it and the diameter of the hole is D2 (D2
Now, ...
2
votes
3answers
163 views
Why does a spring lose its energy when compressed for a long time?
Why does a spring lose a part of its energy when compressed for a long period of time? Is it because the material gets bent?
2
votes
1answer
194 views
Intuitive description of what a “Fermi Gas” really is?
This question is based in the area of material equations of state. I am wanting to know what a Fermi Gas really is. I have searched in several places for a decent description, but I have not found ...
2
votes
3answers
118 views
Electrial Conductivity of Thin Metal Films
What is the best way to find specific/electric conductivity which is dependent of very thin film thickness?
2
votes
1answer
117 views
light absorbing diodes characteristics
Recently, there was a publication regarding some new materials that would let thru light in one direction and either absorb it or reflect it in the other direction; the publication does not clarify on ...
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 ...
2
votes
2answers
51 views
What materials focus EM radiation in the 2.4GHz range
If glass and similar materials refract visible light effectively, what materials would be best for focusing lower frequencies of EM radiation, if any? If not, what other methods exist for focusing ...
2
votes
3answers
119 views
Glass pipe cutting
I want to know how to quickly create the straightest possible breaks in glass pipes
I apologise if this is only borderline suitable for a physics forum - I just hope experts with a lot of experience ...
2
votes
2answers
128 views
Computational Science involve programming? [closed]
I read what is computational science in Wikipedia but the explanation and understanding are not very clear.
So, I could you please give a simple example computational science project and what all ...
2
votes
3answers
94 views
What is the difference between lattice vectors and basis vectors?
Google has not been very useful in this regard. It seems no one has clearly defined terms and Kittel has too little on this.
2
votes
2answers
541 views
Space Elevator on Mars with Today's Technology Possible?
I know it's not possible with Earth today, but With today's level of material science technology, would it be possible to make cable strong and light enough to make a space elevator system connecting ...
2
votes
1answer
549 views
Which ferromagnetic material has the lowest Curie temperature?
It is hard to search for materials by their properties in general and I am trying to find a material with a very low Curie temperature. At the moment I am browsing different sites but can only find a ...
2
votes
4answers
186 views
How does water carve rock?
(More generally, how does a soft material carve a hard material?)
Obviously it happens, but is it a continual process (every drop of soft water carries away a minute amount of hard material) or is it ...
2
votes
1answer
815 views
What will the strength of a sintered steel piece be compared with a cast piece?
By sintering here, I mean specifically deposition laser sintering, i.e., put down a patch of steel powder, zap it with a laser so that it liquifies at least partially, lay down a new patch, laser, ...
2
votes
1answer
71 views
Is shear elasticity the same as shear modulus?
I've encountered both the terms "shear elasticity" and "shear modulus". Are these the same?
2
votes
1answer
112 views
What is nonlocal resistance?
We are first taught to calculate local resistance, where current and voltage are on the same part of the material.
But many experiments measure nonlocal resistance, where current and voltage are ...
2
votes
1answer
170 views
A differential equation of Buckling Rod
I tried to solve a differential equation, but unfortunately got stuck at some point.
The problem is to solve the diff. eq. of hard clamped on both ends rod.
And the force compresses the rod at both ...
2
votes
2answers
90 views
What are the specific electronic properties that make an atom ferromagnetic versus simply paramagnetic?
As I understand it, paramagnetism is similar in its short-term effect to ferromagnetism (spins of the electrons line up with the magnetic field, etc.), though apparently the effect is weaker. What is ...
2
votes
0answers
33 views
Is this 2D structure triclinic?
The only rotation axis obvious to me is rotation by 360 degrees, the identity. Vertical mirror planes I've been dicing and cutting it through several planes and I still see none. Yet, the structure ...
2
votes
0answers
54 views
How can I determine the type of magnet used in a DC motor?
I repair electrical motors in a workshop and sometimes I must repair permanent magnet DC motors and other motors that use permanent magnets. I need to specify type of permanent magnet (Ferrite or ...
2
votes
1answer
112 views
(Botanical) branch bending under gravity
I'm a PhD student in maths, and attended my last physics class some 15 years ago, so you can imagine my competences in the field.
My supervisor (also not a mechanist) cant tell me how to proceed ...
2
votes
0answers
701 views
What is the cause of strain hardening and strain softening?
Why is it, that - if displayed in a strain/stress-diagram - the curve will at first be linear, and then change into a "curved shape", where it will first decrease again, and only later increase again? ...
1
vote
6answers
974 views
Is there any anti-gravity material?
I want to know if there is any anti-gravity material. I am thinking of making flying vehicles which are made up of anti-gravity material so that they will not experience any gravity on them and can ...
1
vote
2answers
379 views
Vibration as a means of passing through solid objects?
First of all, I think this is a weird question but I still want to know whether it's possible. There is a character in a cartoon network series who is really really fast. Sometimes he lets his own ...
1
vote
1answer
38 views
What would be the basis vectors for this 2D crystal structure?
In the above image, I have a 2D crystal structure. The lattice vectors are described by:
a = {-1/2, -Sqrt[3]/2};
b = {1, 0};
and the location of atoms A and B ...
1
vote
4answers
140 views
The requirements for superconductivity
Which properties are sufficient evidence for a material to be not superconducting?
I am looking for a set of statements like
If the material is semiconducting, it is not superconducting
Edit:
I ...
1
vote
1answer
64 views
Getting a given wavelength radio signal given an antenna with real-world constraints
Supposing you are given a transmitting antenna of whatever type of metal is most commonly used these days, and supposing that you are applying an AC current with the intent of transmitting a 1 m ...
1
vote
1answer
79 views
Simulation of broken object
I was thinking and the following question came out:
how an object that is falling is simulated once it hits the ground?
Specifically, I would like to understand how one would be able to simulate the ...
1
vote
1answer
606 views
Does infrared rays pass through polarized glass?
Actually I had asked in another post that "Does infrared rays pass through active shutter glass" but someone just commented that infrared rays dont pass through polarized glass. If infrared rays ...
1
vote
1answer
113 views
what gives the vermiculite it's insultative properties
i know that vermiculite is used in insulation applications.
i found this notion of the R-value of vermiculite, that i don't know if its true.
basically i want to know if the attribute of the ...
1
vote
2answers
218 views
What material can a lens be made from?
I need to make a camera lens that can easily withstand temperatures of about 1000 Fahrenheit.
What should I make the lens out of?
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vote
2answers
558 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 ...
1
vote
4answers
327 views
Will tensile strength keep a cable from snapping indefinitely?
Trying to secure a wall hanging using magnets; me and a coworker came up with an interesting question:
When the hanging is hung using 1 magnet, the weight of it causes it to quickly drag the ...
1
vote
1answer
33 views
If my lattice has an atomic basis, do I also find the reciprocals of the basis vectors to get the reciprocal crystal structure?
That is what my crystal structure looks like. The blue atoms sit on every lattice point (basis vector of $\{0,0\}$) and the red atoms have basis vector of $\left\{{2\over3},{1\over3}\right\}$. The ...
1
vote
3answers
38 views
Trapping EM radiation
Is there a material which can allow light (or any other EM radiation) to pass through from one side as if it is transparent but its other side reflects light like a mirror?
1
vote
1answer
130 views
Calculation of number density from material density
Material density is given by $ \rho =m/V$, where $m$ is mass and $V$ is volume.
Again number density given by $n=N/V$, where $N$ is the total number of particle. How can I calculate number density $n$ ...
1
vote
2answers
153 views
Where does Computer Science background students fit in Theoretical Physics [closed]
I am basically an Electronics student - background in computer science (that's where I want to work). I applied for an internship in USA in a research institute where the group is focused in ...
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 ...
1
vote
1answer
443 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
1answer
89 views
Stretching a piece of foil with a hole
I have a 20x20cm piece of foil with a circular hole of diameter 1cm in the centre.
If I slowly stretch the foil both horizontally and vertically, what happens to the size of the hole?
Does the size ...
1
vote
1answer
166 views
How does compression of carbon atoms work?
From what I understand, it's extremely difficult/ impossible to compress atoms closer together.
I'm wondering how this applies in the case of graphite and diamond, where the carbon atoms adopt a ...
1
vote
2answers
147 views
Is there a readily available (or at least not theoretical) material that reflects only infrared light?
By way of context, please picture those little motion capture lights that are put over an actors body. I am interested in finding out if there is some kind of material that can do the same thing but ...
1
vote
1answer
408 views
Paper stiffness
As piece of paper is folded and unfolded, the stiffness of the sheet may seem to be greatly increased.
To those of you who don't recognise it: take a sheet of A4 paper, grasp one of the edges and ...
1
vote
1answer
260 views
Extracting water out of silica gel [closed]
From my preliminary research I've learned that desiccants are a good (best?) method to absorb water from air. Assuming I'm using silica gel (or kitchen salt, or rice) then what is the best way to ...
