Glass Definition and 658 Threads

Why is there better visibilty when viewing under water through a glass bottom of a boat rather than say looking over the side of the boat?

https://www.guardianmag.us/2023/02/scientists-levitate-glass-nanosphere.html "the nanosphere was suspended in its lowest quantum mechanical state, one of extremely limited motion where quantum behavior can start to happen." To my reading, the glass bead was cooled down and then suspended with...

Supposed someone (like a naughty child) sits on the edge of the cantilevered hardened tempered glass table (see photo below) and it breaks. Would all the table glass break into pieces at same time or would the edge break separately? and would there still be sharp edges? I know tempered glass...

Don't let anyone tell you otherwise. Optimizing Beer Glass Shapes to Minimize Heat Transfer During Consumption.

All of you sound really smart, I have a question for you. This happened in Hawaii, years ago. I was drinking with my highschool friends, we decided who can throw the empty brown Budweiser bottles (the short stocky kind) the furthest from the balcony 10 flights down would go get another round. I...

If centrifugal force dont exist why glass of water moves outward/toward me when I open fridge door? Glass of water moves out in relation to door and in relation to earth, so what force push glass out?

Let's consider an uncovered glass. Air particles are present in the glass. $$ P_1 = P_a$$ $$P_2 =P_1 +\rho gh = P_a +\rho g h$$where ##P_A## is atmospheric pressuere and ##\rho ## is air density. Now, if I cover the glass with a plastic card, then what is ## P_1##? $$P_2 =P_1 +\rho gh $$ 1)...

Hi, I've attached the photo of the diagram, a photo of my drawings on the diagram. for a): Since the prism is an equalateral triangle, all angles inside the prism is 60°. This means the angle adjacent to α is 180° - 60° = 120°, which means the last angle is 180° - 24.5° - 120° = 35.5°. The...

Hi, I wanted some clarification on the mechanism for how EM radiation interacts with standard glass, namely IR, visible and high energy (UV and X-ray). Looking online most sources seem to say the band gap is around 10eV. Since visible light is about 1-3eV visible light will be transmitted. IR...

https://getpocket.com/explore/item/these-people-love-to-collect-radioactive-glass-are-they-nuts It talks about uranium giving off "alpha waves/rays" & "beta waves/rays", and an isotope of U-308. My understanding is that alpha & beta radiation is particle in nature whereas gamma radiation is a...

Hey everyone, I am trying to couple light from an optical fiber connected to an LED (365nm) into a small glass capillary which is pulled on one end and should be used as a small light source. The idea is to use the glass as a light guide. Has anyone tips for efficient incoupling of the light? I...

My answer : According to the question, the glass and the air inside it entered the water. Let's assume that the net force becomes zero at a moment, that is, the sum of the weight force and F is equal to the buoyancy force. By going down in the water, the gas volume decreases, so the buoyancy...

[Mentor Note -- post appears to have been edited based on post #2] Hello everyone! I was watching a Walter Lewin lecture and saw him do something very dangerous, he released a wrecking ball at a certain height from the ground, upon returning the ball did not smash his head. If you watch the...

As far as I know, if vacuum antigravitates, it makes the light that travels through it redshift, e.g. in a very large empty box with mirror walls, light will just lose energy. I am interested in the reverse effect, if we had a very large box or planet with mirror walls, that is filled with...

Hi, I saw that the group velocity for an electromagnetic wave can be calculate with the following formula ##v_g = v_p + k \frac{d v_p}{dk}## Thus, since ##v_p = \frac{c}{n} = \frac{\omega}{k}## Is it correct to say that ##v_g = \frac{c}{n} + k(- \frac{\omega}{k^2})## where ##k =...

Medieval Africans Had a Unique Process for Purifying Gold With Glass And scientists in Illinois have recreated it. https://www.atlasobscura.com/articles/medieval-african-gold Mansa Musa, emperor of Mali from 1312 to 1337, was widely known for his vast wealth in the form of gold deposits...

A red laser with the diameter of 3mm is directed towards a piece of glass. It has the effect, P of 1mW. The angle of incidence is 90 degrees. The glass has refraction index n2= 1,5 and thickness 2 cm. Its front side is convex with a convergence radius,R, of 11 cm. The back side is plane. Whats...

I think the water in the bowl of water will boil first because the glass won't conduct the heat instantaneously, and hence the water in the glass will boil after the water in the bowl. Is this correct? I am guessing this is a trick question and the water in both boil at the same time, but I...

Hi! I am an electronics engineer and I would be very grateful for some help and suggestions with my problem. I am experiencing severe discomfort when working with almost any LCD screen (smartphones, laptops, monitors). Ophthalmologists say that I am completely healthy and they cannot understand...

I think a high enough voltage may have permanently polarized the glass.

A mysterious field of glass fragments, scattered across Chile's Atacama Desert, and aligned in a vast corridor stretching 75 kilometers long (almost 50 miles). They first came to scientists' attention about a decade ago...

I was doing a exercise which considerst he time it takes for light travels a glass with thickness proper D and velocity v. The speed of light is c/n inside the glass. Now, my approach was to go to the glass frame, take the relative speed between the glass and the light using the trivial formula...

I am not sure if the explanation below is enough. This is a high school level question. When rubbing occurs between glass and silk, then heat energy is produced which provides the energy needed to free up electrons in outermost orbits of atoms in silk or glass. But silk has very tightly bound...

Hey guys, I need your help with the following topic on which I couldn't find sufficient information on the internet to solve. In the need to further insulate my velux roof swing window against against airborne motor and tire sound from the nearby street, I came across the idea to install an...

I'm looking to find a way to remove tempered glass that has been shattered from solar panels to make them viable once again. I have no idea what kind of adhesive is used here, but I imagine it is some sort of epoxy. I've tried to peel it off with a pressure washer at the car wash to no avail...

I use the following equations to understand this question/answer. First, C = k(ε*Area)/distance = Q/V = Q/ (E*distance) As a slab of glass is added, k increases and thus E decreases. F=QE, as E decreases, force decreases as well. How does this relate to the 'force attracts the glass into the...

Homework Statement:: Oil Lamp ( Paraffin help ) Relevant Equations:: Not sure what to write here HI folks, I'm trying to make an oil lamp from an old Vodka bottle. The bottle is the usual 750ml and is in a skull shape bottle. ( maybe you know it ) Anyhow I have all the materials and almost...

Could I put this on here for answers please ? If produced a solid glass beam with a spiral column thorough the middle of it would the core be hotter or cooler than the surrounding air? If colder could it be use in conjunction with ground source technology to produce hot water? I not sure how to...

I want to ask that if i use light head magnifying glass is it safe? For embroidery or an idea came to my mind that why not I use Webcam and a big display like 23 inch and then focus webcam on my embroidery and see on my LCD I have also reflector glasses to avoid eye strain totally ? . Because in...

its has been said that light slows down in glass, but some talk about phase velocity and group velocity... then there is the velocity of the photons, which some say is always c. What are those speeds [Vgroup, Vphase, Vphoton, Vlight] in glass, and what do they mean?

i made a simulation of waves in glass and in air. my simulation has led me to believe that if light begins in glass, it can travel to the air, and then move much faster, and then go back into the glass at a point further down. Could this happen in real life? here is the video of my...

Suppose you just poured a glass of champagne, then you drop the glass straight down (so that there is no tilting). Do the bubbles: (1) Continue to rise with respect to the glass. (2) Remain in place with respect to the glass. (3) Sink with respect to the glass.My intuition is telling me that...

Is it possible to create following two shapes from glass using currently known glass mass production techniques? Shape #1: bottle with a prolonged neck that continues into the inner space, like this (cross section): | | | | /| |\ / | | \ / \ / \ | | |...

I have a small LCD clock and a corner of the LCD glass cracked and separated. This small region of the glass lines up with one of the pads on the circuit board and the result is that one of the segments is non-operative. I look at the LCD glass and I can't see any sort of circuit trace. Is the...

The question is stated above. I tried to solve it on my own and I obtained the following three questions: $$\begin{cases} a_{cloth}=\frac{F-\mu mg} M\\ \\ a_{glass}=\frac{\mu mg}m=\mu g \end{cases}$$ Where small m is the mass of the glass and capital M is the mass of the cloth. However, the...

hi, i know you have to use 2t/lambda= m/2 to get the answer of 10.9 um. However i was taught that there would be phase difference caused by reflection, since n1(air)< n2(glass). SO the equation in my head would be 2t/lambda - 1/2= m/2. Can someone explain why I'm wrong?

First of all, I didn't know whether to pick this subforum or the engineering/compsci one, I understand this might need to be moved to a more appropriate subforum. The general approach is fairly obvious, use implicit method to construct the tridiagonal matrix for Thomas method and solve. However...

Some of us may use coffee coaster for our drinks. I was always wondering about that phenomenon and failed to find something on the net yet.

I cannot find a source of uranium glass beads/wands for art making. It is mentioned online that one can make UV glass with a derivative of uranyl nitrate, UO2(NO3)2 . Does anyone know a source of uranyl nitrate, or raw glass material, and what are the minimum safety protocols, such as...

Hello, I am making a DIY UV-C germicidal box as part of my defense-in-depth strategy for protecting my household but I am having trouble determining whether a particular plate of glass that I have will be transparent to UV in the 250-280nm range. The glass in question is from a flatbed scanner...

So, I was studying about general properties of matter and topics like surface tension. I came across the phenomenon of water rising along a glass plate like in the picture. I looked for some mathematical interpretation of this on the internet and in some books. [![enter image description...

Hi, I'm looking for help in knowing which orientation is worse for finding leakage: upside down, sideways or no difference. I have a 30ml glass bottle filled with 26ml of oil that is closed with a glass stopper (cork) applied with a set force. The neck of the bottle is filled with oil when...

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Hi all! Breaking down the question bit by bit: AC is coated with a silver film which acts as a mirror - Okay, nothing as of yet right..? A light beam is an incident onto prism at Point Q such that angle PQB is 40 degrees - This means that my incident angle is 50 degrees as shown below...

I'm aware of the numerous threads on the subject "light inside glass" there have been in the past, in case you will indicate me an appropriate one, but I haven't been able to find a clear answer to the questions: 1) Do photons really exist inside a (homogeneous, linear, transparent, refracting...

This link makes me fondly remember the goofy Star Trek to save the Blue Whales and how Scotty invented something he invented in the future with the help of Spock. Transparent Aluminum https://phys.org/news/2019-11-aluminum-lasers-bendable-glass.html

Hello everyone, Most of you know the Holographic Sights used on weapons to aim. I have a 3d printer and I will try to replicate one of them. I just wonder how the red dot/sight is reflected on the glass without making the light reflected anywhere else? It doesn't have to have exact same...