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).

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290 views

Whats the contact area for elastic contact between a cylinder and a plane surface?

I am trying to determine the contact area between a cylinder and a plane surface of two different materials so that the plane lies tangent to the cylinder. There is elastic contact between the two ...
2
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3answers
341 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 ...
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1answer
97 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?
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1answer
375 views

Learning roadmap for solid state physics [duplicate]

I am a PhD student in mathematics who knows little more about physics than what one learns in high school. For my research on tilings of space and aperiodic order, every now and then I have to skim a ...
0
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1answer
539 views

Calculation of a bending moment

I'd like to calculate the bending moment of a cantilever, fixed at its base, and submitted to a certain stress on a specific spot, but I can't find the proper definition of this bending moment (first ...
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8answers
19k 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?
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2answers
2k views

Materials with a high compressive strength to weight ratio

We know about extremely strong materials such as carbon nanotubes. However, this is only in tension. What are some high strength-to-weight materials (both available and hypothetical) in uniaxial ...
4
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2answers
372 views

Consequences of destroying a space elevator

Suppose there is a fully functional space elevator built on Earth. The base is attached to coordinates $ (\lambda, \varphi) = (0,0) $ e.g., on the equator on the zero-meridian. What would happen ...
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1answer
287 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 ...
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1answer
119 views

Is there real materials have Lieb lattice structure? [closed]

Is there real materials have Lieb lattice structure? Some examples?
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1answer
106 views

Lightest flying solid material [closed]

I need to use a number of lanterns, to write something with it! I would like to use a light material which will bind the lanterns together (separated by space) so it looks like dotted letter. I know ...
2
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1answer
124 views

Is shear elasticity the same as shear modulus?

I've encountered both the terms "shear elasticity" and "shear modulus". Are these the same?
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2answers
238 views

Shape of wall's deformation wave caused by baseball's impact

Clicking through this year's top sports pictures, I stumbled upon this one. I was wondering about the shape the baseball is leaving on the wall. What phenomenon causes this peculiar shape? Why is ...
2
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1answer
215 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 ...
3
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1answer
446 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?
4
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1answer
1k 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 ...
5
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4answers
9k views

Does glass get stronger the longer its under water?

I was reading the internets and I saw an image of of random facts. Yes, I know, its a humor site, but based on the image item #23 I have some questions. Does glass really get stronger the longer its ...
3
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1answer
207 views

What states of matter are possible at lowest temperature?

Near absolute zero, some materials are superconductors. Other materials are superfluids. Others are Bose-Einstein Condensates. Is there a complete list of possibilities? Or is this still a research ...
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1answer
107 views

Characteristics of bloch electron in a priodic potential

Effective mass of a Bloch electron in a periodic potential is negative why ?
6
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1answer
974 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 ...
2
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4answers
223 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 ...
2
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2answers
218 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 ...
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1answer
94 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 ...
3
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1answer
330 views

Why do non-stick frying pans work?

Modern non-stick frying pans use a mixture of titanium and ceramic that is sandblasted onto the pan surface, and then fired to 2,000 °C (according to Wikipedia). Can anyone explain (at the molecular ...
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2answers
234 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 ...
4
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1answer
110 views

limits of diamond anvils for high pressure research

in this wikipedia article regarding diamond anvils, it mentions that the pressure peaks roughly at 300 GPa. My question is why is this so? is the diamond crystal structure collapsing if higher ...
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0answers
38 views

AWG chart for Tungsten

This is the American Wire Gauge (AWG) chart page for Copper that I found from Google: http://en.wikipedia.org/wiki/American_wire_gauge Is there a similar table for Tungsten/Wolfram available? Has ...
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1answer
89 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 ...
12
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3answers
809 views

Why are materials that are better at conducting electricity also proportionately better at conducting heat?

It seems like among the electrical conductors there's a relationship between the ability to conduct heat as well as electricity. Eg: Copper is better than aluminum at conducting both electricity and ...
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3answers
753 views

Liquid crystal shutter with >90% transmission?

Today's liquid crystal shutter glasses, when in the "transparent" state, exhibit only 40% light transmission. They work using two polarizer layers, one which is liquid crystal and goes {vertical ...
2
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1answer
306 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 ...
7
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1answer
2k 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) ...
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1answer
360 views

Are silicone polymers transparent to infrared light?

I know that silicon and even black plastic bags are transparent to infrared light. What about light-colored silicone polymers (take white or green colors)? Are they transparent to infrared light too? ...
3
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1answer
250 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 ...
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1answer
185 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 ...
0
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2answers
996 views

Calculate the weight a simple plank can support [closed]

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 ...
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2answers
2k views

Calculation of the maximum load to the bar

Looking for a way of calculating the maximum weight (W) to the rod with the given length (L) where the rod did not break and that only bend for (b) mm. Need only approximative solution (read: ...
3
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1answer
1k views

Why can glass absorb ultraviolet light?

Please see the following photos. (I cannot post them...) http://i1163.photobucket.com/albums/q554/startanewww/CIMG4545.jpg http://i1163.photobucket.com/albums/q554/startanewww/CIMG4546.jpg From the ...
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3answers
203 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?
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2answers
215 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 ...
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1answer
1k 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 ...
2
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1answer
204 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 ...
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1answer
800 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 ...
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2answers
639 views

How is the stickiness of a fluid measured?

How does one compare the "stickiness" of different substances on a certain surface? For example: Does glue A stick better to steel than glue B? Does water stick better to steel than oil?
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1answer
720 views

Properties to select suitable materials for making permanent magnets

I have read that soft iron is suitable for making a permanent magnet. Because it is required for permanent magnet to have high coercivity and high retentivity. Same text also said earlier that soft ...
34
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3answers
2k 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 ...
9
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2answers
586 views

Why is paper more frangible when it is wet?

My four-year-old daughter asked me why paper tends to fall apart when wet, and I wasn't sure. I speculated that the water lubricates the paper fibers so that they can untangle and separate more ...
1
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1answer
112 views

What is a good reference for the mechanical properties of materials at cryogenic temperatures?

I want to research various the properties of various materials, namely tensile strength at cryogenic temperatures (~20K). I was wondering if a freely available database of material properties exists.
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2answers
277 views

What is the difference between Sapphire and BK7?

What is the difference between Sapphire and BK7 in optics (lenses), is it only about quality?
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2answers
195 views

Behavior of shock waves at relativistic speeds

Suppose I am in a spaceship traveling inertially at a velocity $v$ that is of the same order as $c$. As I pass by a metal bar that is oriented parallel to $v$, someone hits it with another metal bar, ...