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).
Questions tagged [material-science]
1847 questions
308
votes
2 answers
Why do ballpoint pens write better on pages that have pages below them?
If I write on the starting page of a notebook, it will write well. But when there are few or no pages below the page where I am writing, the pen will not write well. Why does this happen?
Ram Keswani
- 2,191
305
votes
10 answers
Why don't metals bond when touched together?
It is my understanding that metals are a crystal lattice of ions, held together by delocalized electrons, which move freely through the lattice (and conduct electricity, heat, etc.).
If two pieces of the same metal are touched together, why don't…
jcw
- 2,711
183
votes
3 answers
How does a knife cut things at the atomic level?
As the title says. It is common sense that sharp things cut, but how do they work at the atomical level?
wtoh
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137
votes
5 answers
Why does paper cut through things so well?
Paper is an extremely flexible material, at least when it is in sheet form. It will deform significantly according to the pressure applied and it is easy to fold.
Therefore, it's extremely counterintuitive that a sheet of paper could cut through…
128
votes
5 answers
Why do wet objects become darker?
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 change its optical properties?
Suma
- 1,432
100
votes
11 answers
If I pull a metal bar for long enough with a constant small force, will it eventually break?
Let's say I have a strong metal bar. I pull it apart with a very small constant force -- obviously it doesn't break. However, this would disturb the internal configuration. If I let go, then eventually the internal configuration would return to what…
94
votes
7 answers
Why do metals only glow red, yellow and white and not through the full range of the spectrum?
Why don't metals glow from red to yellow to green to blue etc.? Why only red, then yellow and then white? Shouldn't all wavelengths be emitted one by one as the temperature of the metal increases?
If some metals do glow at with different colours,…
Dieblitzen
- 1,687
94
votes
9 answers
Why does matter exist in 3 states (liquids, solid, gas)?
Why does matter on the earth exist in three states? Why cannot all matter exist in only one state (i.e. solid/liquid/gas)?
Kiran Kumar
- 1,017
88
votes
8 answers
Will a hole cut into a metal disk expand or shrink when the disc is heated?
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?
What will happen to the diameter of disc?
jojo
- 897
79
votes
2 answers
What is the physics behind origami?
If we fold a paper and then apply pressure on the newly formed crease, it seems that the paper's surface gets a permanent deformation but what exactly has happened to the paper at a molecular scale?
Clemens Bartholdy
- 8,309
56
votes
4 answers
Does anything in an incandescent bulb actually reach its color temperature (say 2700 K)?
This question is inspired by a question about oven lightbulbs over on the DIY stack. It spawned a lengthy comment discussion about whether an incandescent lightbulb with a color temperature of 2500 K actually has a filament at a temperature of 2500…
Bear
- 573
55
votes
1 answer
Why does paper become translucent 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 translucent; but when I attempt the same with water it doesn't as much. Why?
Mozibur Ullah
- 14,713
54
votes
4 answers
What wavelengths of light does a banana reflect?
I do know that there are at least two types of yellow light: a light of a single wavelength of ~580 nm and a combination of green light and red light. (Technically, there could be more yellow light.) And the following two figures are making me…
dkssud
- 753
54
votes
4 answers
How are magnets held together, and why do they not explode?
Imagine we have a magnet (red side is the north pole, blue side is the south pole), and imagine two ways to split it.
The first way:
When we split it by separating the north pole from the south pole, we see that the two pieces are themselves dipole…
MaximusIdeal
- 8,868
53
votes
2 answers
Why does sound absorption in oceans depend on the pH?
I was reading "The Sixth Extinction: An Unnatural History", by Elizabeth Kolbert, and there she comments that high level of $CO_{2}$ in the atmosphere lowers the pH of oceans (which makes sense) and, consequently, diminishes sound absorption:
WHY…
Gabriel Cozzella
- 1,213