Effects Definition and 1000 Threads

When an airy disk is formed, does using a polarizer in front of the pinhole change the shape of the disk?

P. O’Hare et al. Multiradionuclide evidence for an extreme solar proton event around 2,610 B.P. https://www.pnas.org/content/early/2019/03/05/1815725116 https://www.sciencenews.org/article/one-strongest-known-solar-storms-blasted-earth-660-bc Extreme solar events, proton events, are not common...

Hi, I'm in 12th grade and for my senior project I wanted to do an experiment on the effects that copper and zinc have on mung beans. I have copper sulfate pentahyde and zinc sulfate monohydrate, which I had purchased because I have seen information on other similar experiments where these were...

Good day everybody! As we have already known the structure and operation of the cloud chamber, can someone explain to me why the cooling is done at the bottom of the chamber and the heating at the top, but not vise versa?? How this affect the function of the cloud chamber?

Imagine a ball being tossed into 'the air'. At its peak, the ball has a velocity of 0(m/s), but how long does it actually have this velocity for? --> Neglecting the effects of air-resistance. Obviously the ball undergoes constant 'g' the whole time, but the answer to my question doesn't relate...

Let us assume that we have a large gravitational field, then the gravitational redshift can be expressed as, $$\frac {v_{\infty}} {v_e} = (1-r_s/R_e)^{1/2}$$ In this equation ##v_{\infty}## represents the frequency of the light measured by an observer at infinity, ##v_e## is the frequency of...

Hi All, Can somebody tell me what's the speed of the Graviton? As for Cherenkov Radiation, does exist a similar effect for Graviton? Thanks

Do we have reflection when the intrinsic impedance η=E/H between two media are matched but not necessarily the characteristic impedance (assuming a transmission line)? Basically, I have a case here shown below I have two parts with different geometries (this may not be a transmission-line, if...

what are the negative effect of hystersis in metals or negative effects of magnetic hystersis for electrical hystersi over heatin in wires causing low energy transfer and effency

Is it just me or lately there is a big fuss about this? I keep running into news of a recent study that has found smartphones may induce cancer on rats and so on... Did they really find something relevant or is it just the same old story?

The Wikipedia page on gravitational time dilation (https://en.wikipedia.org/wiki/Gravitational_time_dilation) states: "Relative to Earth's age in billions of years, Earth's core is effectively 2.5 years younger than its surface." A clock subjected to less acceleration (gravitational or...

Im interested in using ultrasound to intrfere with sound that comes out of guitar amplifier or sending ultrasound together with normal guitar signal in amp. My questions are : Is it possible? What will it do? Is there anything like it that i can look into? Thank you very much

I know that if some patients are given real medicine while other some are given sweets but not told, for those who get positive effect without real medicine are placebo. However, for the rest of those who don't have positive effect (without real medicine). Does it mean that some of the...

Hey :) I measured the transmission of blue visible light (350-550nm) through lithiumdisilicate ceramics with an ulbricht ball and an spectrometer. The light source was a led dental curing unit (bluephase style). The light guide was positioned direct on the ceramics. Now I wanted to test...

What will happen if a pathogen invades us and our immune system is completely ignorant about it or sleeping? Let us suppose it fails to identify the intruders. Can the consequences be explained pathophysiologically by taking any germ as an example? I want to know how a pathogen causes...

Would there have been any relativistic effects if there was no ultimate speed?

Supposing it were possible to open a stable wormhole close to a planets surface, what could the effects to the immediate area outside the mouth of the wormhole be? Such as radiation, atmospheric anomalies, changes to the planets magnetic field, etc. Thank you for any assistance

The Earth rotates around its own axis within 24 hours. Theoretically, if at the equator perform a tower with a height - H, ignoring its effect on the slowdown of the Earth's rotation (we assume that the material of low density), objects and other complications, at a certain height, the linear...

Hello! I love camping, all year around. However lately I've been hearing much about the hazardous effects of flourocarbons and this got me wondering... Since I didn't know if my tent contained any so called PFC's I mailed the producer and got this answer: "Our tents are not yet PFC-free...

So from what I understand, it's possible to have a very powerful laser pointer where you point at an arbitrarily large and far away surface and make the spotlight appear to move at faster than light. E.g. you can be holding the laser in your hand and you simply flick your wrist. My question is...

I assume that before the Big Bang, there was no Higgs Field, since there was no universe for it to fill. I assume that at the moment of the Big Bang, it began to seep into every corner of the expanding universe and was carried by inflation, that is, moving faster than the speed of light by the...

This is for a story I'm writing that involves supernatural abilities though i often try and find some grounded effect of what would happen. One of these abilities causes the cells in a target's body to be unable to divide, replicate, regenerate, etc. I'm curious as to what the effects would be...

Can anyone explain me ; - What is quantum entanglement and how it effects the space-time and matter in our universe??

Regarding the Quantum Anti-Zeno effect (AZE), we know that frequent measurements of a decaying system (such as a decaying radioactive nucleus) can induce greater decay rates. However, if I understand correctly, you can change the percentage of change in the decay rate. For example, if you have...

Homework Statement This is derivation 2 from chapter 8 of Goldstein: It has been previously noted that the total time derivative of a function of ## q_i## and ## t ## can be added to the Lagrangian without changing the equations of motion. What does such an addition do to the canonical momenta...

Hi, I'm an instructor at an online school, and my text says “ Air pressure is the amount of pressure the atmosphere places on the surface of Earth. Air pressure is usually measured as the weight of the column of air above a square meter (N/m2). As altitude increases, air density decreases and...

This Bloomberg article profiles the Lyrebird startup where AI can mimic your voice or any voice given a snippet of spoken words. and an earlier Verge article on the technology https://www.theverge.com/2017/4/24/15406882/ai-voice-synthesis-copy-human-speech-lyrebird

Let's say I have an apparatus that's set up like this Let's also say that the mirror is infinitely long. If the mirror starts moving at subluminal speeds in the x axis, what would happen to the path of the ray of light? Would the dot made by the ray of light on the wall go up?

Homework Statement for an assignment, we must investigate physics in context, my selected context is a log flume ride, focusing on the final slope. the height of the inclined plane is 13m, the hypotenuse is 17m and the horizontal length is 11m, calculated with a scale diagram and kinematics...

Using a pump we are cycling water through a capsule with filter media inside; while measuring the flow rate (l/min) and the pressure (psi) going in and the pressure going out. The water is cycled back into the same storage tank. As the flow rate increases the differential pressure should change...

I guess i have two questions , is the magnetic field conservative or non-conservative.As far as i can see just looking at a magnetic field we have a curved path hence it wouldn't be conservative, however many textbooks assume it is.Is there something I am not seeing here? Furthermore would...

So in chem lab we were doing experiments in radiation and the TA seems to have no idea how to do stuff, he told us to hold the samples at certain distances from a Geiger counter for 2 minutes at a time. I was tasked with holding an Sr90 sample for roughly 25 minutes, it was a very small sample...

What happens if a glowing incandescent lamp is subjected to intense Infrared Radiation?

One of our classes in the Uni, we have only 3 questions in the exam and we have a curve-grade system. I wonder increasing the question number would have any affects on the curve or etc. Is there any study on this topic ?

The question is whether or not expansion in flat, matter-only universes (no lambda) has any effect whatsoever - no matter how negligible - on dynamics of small-scale systems. Context: It's a variation on the 'is Brooklyn expanding?' type of questions. My understanding has always been that...

Knowing that virtual particles appear and disappear at the Planck length, what is the effect of the annihilation on space-time where the particles used to be?

Hi, we have done an experiment where we have to measure the resistance of a sample of Ge doping-p and how it changes due to a magnetic field perpendicular to the sample with a costant current. We have found that R(B) has a quadratic trend (we have fit the dates with y = a[1+b*B^2] with a and b...

When drilling a thick peace of steel I noticed the drill bit would cut through much faster when it was cool. The difference was minutes versus seconds! Is this a known phenomena in machining or was my drill bit simply contaminated with something or maybe other factors played a role? I've heard...

I have a question. What will happen if you have a long object let’s say a person was lassoed by their feet and spun around by a super strong machine or person. Since the persons head of who is being spun is moving at a much faster tangential velocity then let’s say their feet. If the rope is cut...

Hello, Suppose we humans traveled in a spacecraft to another Earth like planet with the same gravity and atmospheric composition as our own Earth. Suppose we landed on the surface. Suppose we opened the door of the craft, and walked onto the planet surface. Suppose we did not wear a...

My question is perhaps as much about the philosophy of math as it is about the specific tools of math: is perpendicularity and rotation integral and fundamental to the concept of multiplication - in all number spaces? As I understand it, the product of complex numbers x = (a, ib) and y = (c...

It is generally said that excess salt consumption leads to water accumulation as a compensating mechanism as the cations of sodium builds up excessively. My doubt is, if the sodium chloride (salt) consists of chloride (anions) as many as sodium (cations), don't the net effect of the increase of...

Issues about two topics were discussed in another thread. https://www.physicsforums.com/threads/do-solar-tides-affect-Earth's-orbit.933073/ The topics are: how do the lunar tides (1) cause the Earth's rotation to slow down, and (2) cause the moon to move away from the Earth. This thread is...

Note: this is a re-post from the physics area because this thread is probably more appropriate for this content. There is a lot of rather contradictory information present on the biological effects of acoustic weapons with a bevy of scientific articles claiming that they cause harm to...

Hi, Can someone please anlayse the visual effects for light travel in the documentary 'Journey to edge of the universe' Especially around the 43:12 and the 1:02:20 mark. Can you also tell me if it is or is not an accurate depiction of what we should be seeing theoretically?

Say that I have a neodymium doped yttrium aluminum Garnet (Nd:YAG) laser crystal rod. If I'm using this crystal in a laser, will the size of the crystal affect any characteristics of the laser itself. That is, will a laser containing a 4-by-7 mm Nd:YAG rod operate differently than a laser...

https://www.sciencedaily.com/releases/2000/06/000602074805.htm The article says that the zeno effect only applies to certain systems while the anti zeno effect applies to all systems. Is this true?

Hi, I am attempting the following question: 1. Homework Statement If the extinction in the infrared K-band (filter central wavelength = 2.13 micrometres) is 10 times less than it is in the optical V-band (filter central wavelength = 550 nanometres), what affect would a cloud of Av = 3 have on...

Homework Statement [/B] Hi everyone! So I've got this similar problem as I posted yesterday, but this one is slightly different due to the presence of gravity: A particle in gravitational field ##~~g## starts traveling upward (positive direction) along the y-axis from ##~~y=0## with the...

I'm looking for a way of using ultrasonic cleaning to clean the inside of a glass vessel filled with some sort of fluid by transmitting ultrasounds through the glass, rather than submerging the entire glass vessel. If an ultrasonic transducer, let's say something with a maximum frequency of 40...