Classical Physics

I see particles as little points of light going about O(3cm) before annihilating. This can be seen by looking at the blue sky and focusing about 100mm from the eyes. I would be vindicated if calculation showed a distance (stable time) of O(3cm) for general particles.

We have that for an observer outside a black hole, objects takes an infinite amount of time to cross a Black Hole event horizon. Shouldn't we then see no gravity waves from merging Black Holes? The gravity waves should take an infinity of time to come out of the event horizon. Since time stops at the event horizon of a black hole, shouldn't we see a frozen image of the star that collapsed? This instead of a flat cloud with a hole in it?

Jon Butterworth agrees wit me that there is something physical out there. See: At 1:01:02 into the video.

I have it that this correspondence is only valid in a Universe made of Anti-de-Sitter space. Some web pages and videos talk as if it is valid in our Universe.

Can Entropy be simply defined as the tendency of all matter to disintegrate and annihilate in its transition to pure energy?

Please, explain how this toy (https://www.weber-holzspielzeug.de/holzspielzeug-holzspiele/klopfspechte/klopfspecht-rot-blau.html) works through Physics view?

I am trying to find the principle of moment of inertia in round house kick. Can someone help me explain using the calculus.

I am working and have problem related to temperature conversion. I am looking for a solution, software or website that can allow me to convert fahrenheit to celsius easily, quickly and efficiently. I don't like looking up formulas, then entering numbers into the calculator. That is really complicated and takes a long time. Can someone help me? Thanks everyone

In classical physics we know photon emits when electron move from higher to lower state but in nuclear fusion photon emits when neutron turn into proton. Is both correct?

I just got to know...

Good day. Have never seen otherwise than the barrel tip rising when a gun is fired. There is other orientations that do not happen, as sideways, downward... Perhaps is different in artillery but; why is the typical recoil producing that upwards motion ?

I have a question about the resolution of this exercise: I tried to solve this problem with the following steps: For the 1º law of thermodynamics, 𐤃U = q+w. As q = 𐤃H at constant pressure, I assumed that in this process q = - 15 kJ. As a result, 𐤃U = -15 - 22 (because was an expansion) and for this reason, 𐤃U = -37 kJ. However, the book has this resolution I understood why the book used this method, but I did not understand why my method is wrong.

With the war on the continent hotting up I would like to know how to protect my computing equipment against an EMP attack. I would like to avoid the whole "you'd have more things to worry about" line, and just stick to the science please. Specifically, how do I test a system ? I was thinking about placing a cheap HDD in an EMP protective environment and then inside a microwave, as I do not have the necessary devices to test for signals. I read about bags, but unless ironed the zip lock seal is a weak point. It seems that metallic cloth gives favourable results, and it's very much more flexible and robust, compared to a polymer bag. Any advice please.

In this work are investigated details of an elementary electric and magnetic dipole radiation at distances much greater than size of the emitting element. Debatable conclusions are drawn. Formulas are given in a cylindrical coordinate system (ρ,φ,z) r2 = ρ2 + z2 Given this, it is possible to write expressions differently for ρ and z For example, 2 - 3 · ρ2 / r2 = 3 · z2 / r2 - 1 For all values ∂/∂φ = 0 (cylindrical symmetry) Time derivatives are denoted by a quote ' Electric elementary dipole Charge oscillates along z-axis near zero point with frequency ω, amplitude of dipole moment is P0. Dipole moment: Pz = P0 · cos(ω·t)…

Could we see the universe at all if Dark matter were visible? I would think not if it makes up so much matter in the universe. Thoughts

Hi, In Mod-01, Lec-02, beginning at 54:10 Balakrishnan discusses the "inverted oscillator" having energy 1/2 m qdot^2 - 1/2 m omega^2 q^2. https://www.youtube.com/watch?v=8X1x9RLaaxc Discussed further in Lec-03. Is the "inverted oscillator" only fictitious? If a realization exists, I must have a mental block to imagine it. Thx, ... P.

Hi, I have a project that needs an altitude calculation from the sensor I'm using that outputs Millibars. Can anyone help please? Most of the calculations I've seen result in Feet. Cheers, Camerart.

Why in an irreversible process, is the pressure constant? I understood why I should use Wirrev = -PΔV, but I did not understand why the pressure is constant in this process.

Suppose I coat a surface with 2 layers of paint -one is black and the other white. If the white layer is underneath the black layer and the top (black) layer is exposed to sunlight, does the white layer work as a thermal insulant? I can see the black layer gets hot but does this heat transmit to the surface across the white layer beneath as well as it would if the white layer was not there? (So does a layer of white paint insulate against the transmission of heat when we are not talking about radiation but transmission via direct contact?)

I'll keep this short & sweet. Why are echoes only partial as opposed to whole? What I mean is if I shout "I love you", the echo is "love you" and not "I love you" which is what I actually said. The echo is truncated, the first word/two is dropped as it were.

Assuming both objects are identical in size and shape, does gravity effect how much energy is required to maintain speed on a moving object with a higher mass than another object?

http://www.physicsclassroom.com/Class/waves/u10l0c2.gif Why isn't the tension force's module equal to the gravity force? If the tension force is larger then shouldn't the body be moving up?

good evening, I am currently working on a device. I'm still at the modeling stage. I make this publication in order to be able to exchange with scientists or experts because I have the impression that certain parameters escape me but I cannot see which ones. I apologize in advance if my post is inappropriate. Cordially

I could my self move any megalithic stone in the world. I have always wondered why they cut the larger stones with so flat surfaces already in the stone quarry. This is why...... Just give me 100 liter of mercury and I will build a narrow fit channel, for any large megalithic stone, and build the channel so that front of the channel have room for the stone to be able to float and be moved the larger amount of mercury under the stone as the mercury is transfered under and beside the stone to the back. Then I gather the mercury, fill in behind the stone and dig up in front of it, to be able to make the stone to float and pushed another bit …

Exercise: Considering an intrinsic silicon bar at room temperature 300 K where concentration of electrons and holes with acceptor type impurities ( type P) in a concentration of 4*10^17 cm-3., q = 1.6*10^ (-19)C, kT=0.0259 eV, ni = 1.45*10^(10)cm^(-3), Eg=1.1 eV. I'm having a hard time finding Ec and Ev, if I use the equation I lack data to get this reference if I use the concept of a graph, what I need is to find the value of Ec and Ev. If I describe that Ef -Ec = - Eg/2, the values are very high there's another equation missing that I'm not able to fit here I don't know if I should be Fermi Energy, but if I insert it as a…