Questions tagged [glass]

A glass is a type of amorphous solid whose structure is dominated by excluded-volume effects. Use this tag for questions about the glass transition and the thermodynamics and statistical mechanics of glasses.

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Why does glass break at a given momentum?

My question is:Why is it more accurate to suppose that a sheet of glass will break, after being hit by a projectile with a given momentum, than suppose that it will break after receiving an impact ...
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Determining the refractive index of a glass slab using a travelling microscope

In this practical video of finding the refractive index, the reading is being taken by placing the travelling microscope perpendicular to the slab. But I've learned in another video(Frame Shot) if you ...
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If a photon is powerful enough, will it not pass through glass?

So I know how glass works, it has a large electron gap so the photons that hit it don't have enough energy to move the electrons into a high energy state and instead pass through because the amount of ...
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What opposes a smooth motion of a rubber eraser on a glass surface?

A metal block smoothly moves on a glass surface. But a rubber eraser doesn't move very smoothly on a glass surface. In each of the cases, the surfaces are smooth at the macroscopic scale. If the ...
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2answers
112 views

Why does a laser beam stay coherent when it passes through glass?

If I have a coherent laser beam and I shine it through some glass, the light will slow down because it will interact weakly with the atoms in the glass. However, the beam that comes out the other side ...
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1answer
114 views

Why is glass really transparent? [duplicate]

Glass is an amorphous polymorph of silicon dioxide, melted and quenched so that grain boundaries grow uniformly and are small with respect to visible light. Its an oxide not a metal and has a large ...
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28 views

Theory or method on how to calculate the pressure needed to push a viscous fluid through a narrow slit

I need to calculate the minimum amount of pressure I need to apply to a piece of molten glass to start making it pass through a narrow slit - think 1 kg of glass and a 0.2 mm slit. At this point I ...
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1answer
26 views

Can a light block/reduce another light if projected in exact opposite direction?

For my project, I want to block a light passing through clear window glass temporarily, without manual work and without a curtain etc, want to be able to see through the glass, unobstructed if ...
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24 views

Why is frosted glass reflective at an angle? [duplicate]

I have a Pixel 3, and the back of the phone is frosted glass. I noticed today that if I look at the back from a wide angle it becomes reflective, whereas it is opaque when looking directly on. What ...
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Why doesn't water actually perfectly wet glass?

According to many high school textbook sources, water perfectly wets glass. That is, the adhesion between water and glass is so strong that it is energetically favorable for a drop of water on glass ...
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What is the purpose of glass in mirror as it only reflect very little light?

In a typical mirror there is a thick layer of glass followed by a thin layer of silver coated on one side of the mirror which reflects most of the light, what purpose do the glass have?
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Why glass is considered as an opaque body…? [closed]

We know that the transmissivity of glass is 0 then also in general conditions it is taken as an opaque body and also in some books, it is taken as an opaque body.
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Can amorphous solids have energy bands?

One can understand the formation of energy bands from the Kronig-Penny model which assumes a periodic potential. But I heard that even if the potential is aperiodic, for example in amorphous ...
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Star Trek - Transparent Metals Possible?

Is the concept of transparent metals (like the transparent aluminum in Star Trek IV - Voyage Home) a real-life concept? Or is it far-fetched movie fiction? Thus my main question then is: could we ...
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Can a glass screen protector reduce the impact on a phone?

Glass screen protectors supposedly protect your phone from impact. A youtube comment by McZidanne sums up this idea pretty clearly: The thing about tempered glass cover isn't the protection they ...
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25 views

Cooling liquid inside a pint glass with an aluminium plate

Basically the title. If I have a very cold aluminium plate (don't know the temperature, but enough to have frost) and put a glass pint glass on top of it with liquid inside of it will that cold ...
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1answer
40 views

Best glass to reflect visible light (mainly Green)

i have a laser source which emits green light underwater (kept collimator under water) and planning to reflect the green laser back to free space(project is to establish air water interface). I want ...
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Why is fused silica superior to N-BK7 in terms of thermal lensing?

In optics lab, the two commonly used types of glasses are N-BK7 and fused silica. The lab wisdom has been that fused silica is superior to N-BK7 in terms of thermal lensing. And indeed it seems so. ...
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Weird Reflection Pattern in Reading Glasses

While fidgeting with a pair of reading glasses, I noticed a strange reflection pattern (shown in video and photo). I would appreciate it if anyone that knows more about this could help me figure out ...
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Can a piece of glass get higher than the height the original cup of glass fell from?

If yes, what physics concepts make this possible? This isn't for any class or anything, is just a honest doubt of mine.
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150 views

Why was the glass broken in the Lobby but not above the impact zone? - 9/11

Disclaimer: I do thoroughly believe that 9/11 was a terrorist attack, so please don't start arguing whether it was an attack or inside job, focus on the question. Also: I was about to post this in ...
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1answer
60 views

A metallic container when hammered deforms but a wine glass when falls or hammered breaks. Why?

A wine glass breaks when it falls from hand or is hammered. But when a metallic object (say, a container) is hammered, it only deforms without breaking. Why? Is it somehow related to the fact that ...
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1answer
262 views

How does one do 3D subsurface laser engraving for relatively translucent minerals?

3D Subsurface Laser Engraving works for clear glasses like Schott BK7 and B9 Borosilicate Glass. How does one do the same for relatively translucent minerals? I have read research papers on using ...
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Refraction: Swimming goggles, short-sightedness, and underwater vision

I have thought of this question due to personal experience. I am short-sighted, and over the last three years my short-sightedness has worsened. Taking a lifeguard certificate again now that I did ...
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Why do we disorder-average before/after taking the logarithm of the partition function for annealed/quenched disorder?

Pg. 19 of these notes says Crucially, the [disorder] average $\overline{\log Z}$ has to be computed after taking the logarithm. Such an average is called quenched ... Computing the average first, ...
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Why would/do you wet glass after scoring it to break it?

In this youtube video about a water cooled desktop PC build log the author uses glass tubing to route the water around the system. Around 4:08, when the first tube break/cut is shown, the author pours ...
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Why does molten sand cool to form glass and not return to it's original yellow form?

I came across this website on the internet: http://www.explainthatstuff.com/glass.html. In this website, it is said that When molten sand cools, it doesn't turn back into the gritty yellow stuff ...
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Why iron sparks damage the glass surface but do not harm leather apron?

Sparks from electrical welding or from electrical grinding damage surfaces of glass or tiles while they do not damage the leather apron and even plastics. For example protecting glass in the old ...
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Why does my beveled mirror make triplicate “ghosts”?

Here is a picture of my power adapter. You can see in has one green LED lit when charging. Now here is a picture of my mirror with beveled edges. When I view the power adapter in the mirror, I see ...
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Will lime soda/borosilicate glass tubes glued/sealed with indium leak or crack?

I want to evacuate steam from a vacuum chamber with a dry ice or LN2 cold finger. I'm planning to connect the vacuum chamber and the cold finger via a tube. This inner tube will be glued/sealed with ...
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290 views

What are eclipse glasses made of? [closed]

What is the principle of eclipse glasses? Are they just high optical density plastic, or do they do something fancier? Could I make my own by taping ND filters into cardboard? I tried Googling ...
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1answer
764 views

What is glass: amorphous solid or supercooled liquid?

I have read glass is amorphous solid and also supercooled liquid. I know that all solids are frozen liquids. But is it fair to say that everything which is an amorphous solid is also a supercooled ...
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530 views

Is it possible to create glass that is impassible to infrared radiation?

I read an article today about how UPS has covered some of their trucks with frosted glass to allow drivers to see and find their packages with greater ease. However, one of the drivers noted the ...
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Why do ring stains form when leaving glasses on wood? [closed]

From wikipedia: Coasters protect the surface of a table or any other surface where the user might place a beverage. Without coasters, you will often get a ring stain on your table like this: What ...
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1answer
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How and why would a glass table break in this manner?

Recently, a relative of mine came to me asking me to explain a strange physics phenomenon. She had 3 glass tables; 2 small and one large arranged neatly such that the small tables were half enclosed ...
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Why glass always breaks into sharp pieces?

I understand that common glass and pottery (though not, for example, the glass of a car's windscreen) breaks very easily because it is very brittle and it has a great number of "cracks" in its ...
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Why don't eyes fog up?

I took off my steamy glasses to be able to see and this question came up to my mind. Which is the physical reason for our eyes not fogging up like glasses do?
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More light reflected off of double pane windows?

In glass windows, you get light passing through and light reflecting off the front and back surfaces. Would you get more light reflecting off of triple or double pane windows? Because you have double ...
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Is there an entropy crisis in Spin Glasses?

If you cool a material and avoid crystallization, you get a supercooled liquid and ultimately a glass. If you extrapolate the entropy of the supercooled liquid, at some point it intersects with the ...
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80 views

what is the intensity of photon before and after striking the glass prism?

during dispersion we all know that white light enters in to the prism and disperses into the visible radiation, my question is whether a glass prism can eliminate other wavelengths and allow only ...
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Which phenomenon does a normal window glass shows? [closed]

As we are able see outside from our window glass since it shows refraction in day but what happens in night as in night we are unable to see out since it shows reflection in night and sometimes it ...
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1answer
579 views

Forces behind pulling two sheets of glass separated by a thin layer of water [closed]

I am currently a high school student in South Korea. I was assigned to conduct a physics research project in school, but I really cannot even get started on solving it and I was wondering if you could ...
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1answer
1k views

Where does Light go if it is in a glass prism and why?

I know that photons/light bends or bounces when it hits glass so if it was in a glass prism where would it go. I know that light/photons hit the glass at different angles and if it hits at almost a ...
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1answer
176 views

Non-glassy amorphous solids

According to Wikipedia: A glass is any "solid that possesses a non-crystalline (that is, amorphous) structure at the atomic scale and that exhibits a glass transition when heated towards the liquid ...
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What will a glass look like in 500 years?

The glass is in a metastable state. It is changing constantly. So what will a piece of glass look like in 500 years in room temperature?
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What makes Obsidian edges sharper than other glass?

Obsidian is a volcanic glass with a reputation for being extremely sharp. Some surgeons use obsidian scalpels rather than high-quality steel surgical scalpels. At the same time, glass blades are used ...
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1answer
181 views

Defects of smart glass (electrochromic glass)?

Smart glass is a type of glass that uses electrochromic mechanism to change it's light transmission properties in response to voltage, and it's made by sandwiching certain materials between two panes ...
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Is ice a type of glass?

It's kind of a tricky concept I assume, on one side you got those neat shared vertices of SiO2, on the other (water) you don't really have shared vertices, only kinda (but they still want to align ...
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262 views

Glass Hardness and Pressure

How is glass hardness defined? I understand that ordinary kitchen knives cannot scratch most toughened glass, such as the ones found on cell phones. However (I once tried) - with enough pressure, one ...
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1k views

How does tempered glass work?

I've read that tempered glass work by heating and then rapidly cooling the glass so that the outer layer 'freezes' (stops expanding/contracting) but the core contracts further as it cools. I'm told ...