The United States Naval Reserve (Women's Reserve), better known as the WAVES (for Women Accepted for Volunteer Emergency Service), was the women's branch of the United States Naval Reserve during World War II. It was established on July 21, 1942 by the U.S. Congress and signed into law by President Franklin D. Roosevelt on July 30. This authorized the U.S. Navy to accept women into the Naval Reserve as commissioned officers and at the enlisted level, effective for the duration of the war plus six months. The purpose of the law was to release officers and men for sea duty and replace them with women in shore establishments. Mildred H. McAfee, on leave as president of Wellesley College, became the first director of the WAVES. She was commissioned a lieutenant commander on August 3, 1942, and later promoted to commander and then to captain.
The notion of women serving in the Navy was not widely supported in the Congress or by the Navy, even though some of the lawmakers and naval personnel did support the need for uniformed women during World War II. Public Law 689, allowing women to serve in the Navy, was due in large measure to the efforts of the Navy's Women's Advisory Council, Margaret Chung, and Eleanor Roosevelt, the First Lady of the United States.
To be eligible for officer candidate school, women had to be aged 20 to 49 and possess a college degree or have two years of college and two years of equivalent professional or business experience. Volunteers at the enlisted level had to be aged 20 to 35 and possess a high school or a business diploma, or have equivalent experience. The WAVES were primarily white, but 72 African-American women eventually served. The Navy's training of most WAVE officer candidates took place at Smith College, Northampton, Massachusetts. Specialized training for officers was conducted on several college campuses and naval facilities. Most enlisted members received recruit training at Hunter College, in the Bronx, New York City. After recruit training, some women attended specialized training courses on college campuses and at naval facilities.
The WAVES served at 900 stations in the United States. The territory of Hawaii was the only overseas station where their staff was assigned. Many female officers entered fields previously held by men, such as medicine and engineering. Enlisted women served in jobs from clerical to parachute riggers. Many women experienced workplace hostility from their male counterparts. The Navy's lack of clear-cut policies, early on, was the source of many of the difficulties. The WAVES' peak strength was 86,291 members. Upon demobilization of the officer and enlisted members, Secretary of the Navy James Forrestal, Fleet Admiral Ernest King, and Fleet Admiral Chester Nimitz all commended the WAVES for their contributions to the war effort.
Is it fair to say that all energy from a Gravitational Wave that enters the photon sphere of a Black Hole is destine to become part of that BH?
And other parts that remain just outside of the photon sphere would experience gravitational lensing? Perhaps focusing the GW to an area of much...
Problem Statement: 1) The wavelength of an electromagnetic wave after reflection at angle on a surface
[A]. remains same as the wavelength perpendicular to the surface
.
remains same in the free space @
[C]. increases in actual direction of propagation
[D]. decreases in actual direction of...
When an object is hot its particles are moving faster than when is cold, right?
I've searched that particles are electrons and protons, so it means that if we warm a object the electrons will be moving or even accelerating. Every charge accelerated creates Electromagnetic Waves (or light)...
I am trying to learn about the dispersion of waves and used one of Walter Lewin's lectures (see below) as a source. I understand phase and group velocity and dispersion relations, but I don't understand when/what kinds of waves are prone to dispersion.
For example, a simple wave in the form...
Can you transmit em wave with antenna much smaller than its wavelength? For example. ELF antenna is very long. Can you make one small enough to fit in the pocket by the device constructing the long wavelength part by part?
There are many fluid dynamics applications such as pipe flows, jet flows, boundary layers where we ignore any sound waves present in the system. I don't understand this though, because all sound waves are caused by pressure disturbances so why can we ignore these pressure disturbances when we...
Electromagnetic waves are oscillations of the electrical/magnetic field which propogate through space. So one might predict that the presence of a magnet/charged particle would effect their propogation somehow, like distortion or interference (eg, light might get refracted in a magnetic field or...
I don't know in which category this subject belongs to. Anyways, here it is:
https://www.sciencealert.com/a-new-study-backs-up-claims-that-sound-waves-really-do-have-mass-after-all?fbclid=IwAR2Cmsxm_Garm0PVn03f4UxVQ8adcK4Il3A_N7bUbJT1KaGR1ZfCbGuWVLE
How exactly is this measured? Can we expect...
I wonder why electromagnetic waves don't escape from a black hole while gravitational waves (obviously) do.
What is the difference between the two kind of waves?
And between gravitons and photons?
thank you for your attention
I am reading the following paper on the basic physics of a binary black hole merger: https://arxiv.org/ftp/arxiv/papers/1608/1608.01940.pdf
Imagine two black holes orbiting each other until a point they merge.
As you can see in Figure 1, the wave period is decreasing and thus the frequency...
Gravitational waves are produced by accelerating masses. Since all space is curved -- more curved near large masses stars, less curved in intergalactic space -- all moving masses are being accelerated to some degree. Do all moving masses therefore produce gravitational waves? If they do, will...
Two black holes that are orbiting and collide give off mass in the form of gravitational waves before the collision. Do these waves get absorbed by something, or is this mass lost to the universe?
hi, when we try to find the speed of a wave on a rope v = (F/u)^1/2, we use the fact that if the angles are small then sin x = x. I understand the approximation but not WHY we use the approximation. We say delta(Theta) is small (and then amplitude is small) then ... . So the proof is only...
Light is said to consist of photons or electromagnetic waves.
I'm not asking which view is correct, what conditions make one
view or the other more useful, or advantages and disadvantages
of each view. I am assuming the two views are compatible to
the extent that the wave character of light can...
Part C.
First of all, I am not entirely sure what the problem means by "loops." (I see the loops, duh ;)) but I am not sure what quantity they represent. I am guessing it means harmonics, in which case M would have to be lessened to make a greater wavelength. This is because the extension of...
I'm not an expert in this matter, and at best only aware of some superficial facts and a layman's understanding of them. So please forgive me for any ignorant mistakes in my thoughts, and kindly point them out to me.
Going by the Lambda-CDM model, the expansion of the Universe will eventually...
First I worked out the dispersion relations, which is pretty easy:
##M \ddot x_j = K x_{j-1} + K x_{j+1} - 2K x_j -mg \frac {x_j} {l} ## (All t-derivatives)
We know ##x_j## will be in the form ##Ae^{ijka}e^{-i\omega t}##
so the above becomes:
## -\omega^2M = K (e^{-ika}+e^{ika}-2)-\frac {g}...
A couple of questions on this. How would the sound get reflected back from the surface of the water? And therefore create a stationary wave would the sound not travel though the water at a faster speed then reflect back and intefere? Or does a small amount of the sound reflect back? Part B...
I have a basic understanding of Huygens principle, but I don't quite understand why sound waves follow huygens principle.
When sound travels, particles travel back and fourth in one direction, so how do sound waves end up traveling in all directions after traveling through a slit?
Do sound...
Hi, I'm looking for a book that deals with the mathematics and the physics of waves (sound waves, electromagnetic waves, maybe optics). Basically just "classical waves" (I'm not very interested right know in the applications to quantum mechanics). My math background is (courses that I took)...
I've seen this video:
There it is explained that an electromagnetic (here radio) wave has a phase shift if it was radiated in horizontal polarization, but it does not experience the phase shift when it was emitted vertically polarized when it gets reflected on the ground.
When reading up on...
I am a high school teacher and we were discussing waves and electricity in class today. One of my students asked me if electricity is a longitudinal wave or not and I had no idea how to answer.
So, I realize that electric fields are what drive electrons to move through conducting wires, but...
If I am given the width of the slit (b), wavelength of the light (λ), and the distance of the slit from the screen (D), how can I find the width of the central maximum (d)? My book says d/2=Dλ/b, but with no explanation and I don't understand why. Where does this formula come from?
Thank you...
We know that the charge on capacitors as a function of time takes the general form of:
##Q(x,t)=qe^{ijka}e^{-i\omega t}##
The voltage at each capacitor:
##V_j = \frac 1 C (Q_j-Q_{i+1})##
From KVL we have differential equation of t-derivatives:
##LQ'' + RQ' = V_{j-1} - V_{j}##
##LQ''+RQ'= \frac...
A few years go, we detected a gravity chirp from the collapse of binary black holes.
The initial total mass was about 21.7 solar masses. The end result was about 20.8 solar masses.
The difference was presumably contained in the gravity wave.
I believe, under the right conditions, an object...
Again I am really confused, but I just put the traveling wave as:
##\psi(x,t) = Dcos(kx- \omega t)## for positive x
##\psi(x,t) = Dcos(kx+ \omega t)## for positive x
Then I simply differentiated and plugged in ##x=0##
##F(t) = - T D k sin(\omega t)##
and from this
## \langle P \rangle = T D^2 k...
I learned that standing waves form when the incident wave's frequency is equivalent to the reflected wave's frequency. But I also learned that according to Newton's 3rd law, when a wave hits a boundary, the reflected wave continues to travel in the opposite direction but has equal frequency and...
Basically as the title says.
I'm interested in the naturally occurring EM waves, and I would like to know the strongest EM waves out there. I'm not talking about "strong" as in energy per photon that is proportional to the frequency, but about the overall energy transported by the wave that is...
Outside of QM, do perfectly linear waves really exist in nature? I am referring to just those waves that also have dispersion - in which the wave components have differing phase velocities.
... or are we just using the mathematics of linear systems to approximate nonlinear systems?
Thanks in...
Or both?
The cycling between 'stretch' and 'squeeze' is caused by the orientation changing of the black holes with respect to us. Correct?
This is understood as waves (or pulses) moving through space, Correct? So they take time to get to us.
So, consider the orientation which yields us being...
From what I have read gravitational waves are caused by the acceleration of massive object causing ripples in space time. What specifically causes this, and how does general relativity predict these. Does it have to be a high density of matter, or a large amount of it. How do these waves affect...
Good day,
I do not fully understand the physical mechanism of formation of Rayleigh waves at the free surface. While their derivation is quite clear and obey free-boundary conditions, it is not clear their physical mechanism.
Could you please correct me in my discussion. Incident P-wave can...
Since light intensity is proportional to the amplitude of the EM wave, and wave amplitudes undulate up and down, does this result in natural intensity flickering of observed light?
For visible light, the frequency is extremely high, but it might be more easily observable in ELF waves.
My textbook explained that it would be hard to see the wavelength properties of a tennis ball because we would have to find a very tiny slit in which to pass the tennis ball through. The wavelength of the tennis ball can be calculated using debroglie formula: wavelength = h/p
I was wondering if...
Homework Statement
https://imgur.com/lGas78X
The solution to this question says 450Hz. However, when I attempted to compute the frequency using the wave equation and find the normal mode solutions, I get 750Hz
2. Homework Equations
I suspect that the solution could be wrong, is that the...
I had to find the phase difference between sound waves created by two sources at different distances from a given point. I found the correct answer to be about 13.4.
Would any other answer of the form (13.4 + 2npi) also be correct, assuming n is a non-zero integer? Or is 13.4 the only correct...
I've wondered this for a while but not known how to ask the question,
If light is a transverse wave, then what is it transverse to?
To elaborate, light travels in three-dimensions, radially. To me, this seems analogous to the sound wave, with pulses of pressure moving longitudinally to the...
Hi All,
i have been mostly into the structural analysis domain ...now want to explore the world of sound waves/Acoustics. What should be the best way to start with?
Regards
Kapil
1. Problem Statement:
The pressure in an gas tube of length L stretched along the x-axis is given by
P(x, t) = Patm + P1(x, t) + P2(x, t) (1) where ,
P1(x, t) = 20 [P a] sin (−5.9 x − 1300 t )
P2(x, t) = 20 [P a] sin (5.9 x − 1300 t )One open end of the air tube is at x = 0m. By how much does...
Homework Statement
Why working formula for transverse and longitudinal arrangement in melde experiment different in Melde's experiment ?
Homework Equations
None. The corresponding equations are all derived from the same fact.
The Attempt at a Solution
So, I have understood that the tuning...
How reasonable would it be to model near-colliding of ultra-relativistic black holes by the collision of pp waves? Wkiki, for instance, says that the Aichelburg-Sexl ultraboost space-time models the space-time near an ultra-relativistic black hole, and that it's a type of pp wave spacetime...
Hello. I started to work on pedrotti optics book (2nd edition) and i got confused about what is relativistic mass and why we use it rather than kinetic energy (1/2mc^2)?
Also in the beginning of these explanations there is one equation i barely understand nothing out of it. Could you please...