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.
In general, it seems that higher frequencies of a wave dissipate more than lower frequencies.
For sound waves, it explains why you can hear lower pitches from farther away. For a vibrating string or plate, the higher frequencies also dissipate first, with the fundamental fading last. For water...
Not a physicist. Background is in electronics over many years. Have recently been "binge" watching youtube lectures on the "dreaded" QUANTUM MECHANICS by various people(Susskind, Feynman et al) and trying to comprehend the whole thing.
While I can generally follow the lectures I must admit the...
Hi all!
These days I am brushing up my knowledge on EM Waves. I begin with the introductory level but I don't mind to engage in an advanced treatment of the topic.
At the very basic level I had a high school book, the mentions straightway that if the wave carries with it an energy U, it posses...
My attempt:
I think ##x## is the path difference so by using trigonometry, I got ##x=d \sin \theta##
But my teacher said the answer is ##d \cos \theta##
What is my mistake? Thanks
Edit: Sorry, I found my mistake. My ##x## is not the path difference
The solution provided in the manual poses that the point halfway between the nodes at each speaker is an antinode of pressure (node of displacement) but isn't that a contradiction to the fact that the speakers are in phase? My first thought was that they must interfere constructively and have...
Based on Maxwell's Law, the speed of light can be defined by:
$$c= \frac{1}{\sqrt{\epsilon_{0}\mu_{0}}}$$
Based on that, can we find a medium where a mechanical wave travels faster than a electromagnetic one? If so, how does that works?
I am not an electrical or electronic engineer. I am trying to understand how a simple, series LC circuit running at it's resonant frequency can generate EM waves. I believe, based on what I have read, that the frequency of the generated EM waves will be the resonant frequency of the circuit...
The exercise is to derive the form of the symmetric, trace-free and transverse gravitational wave perturbation ##\hat{E}_{ij}## to the FRW metric$$ds^2 = a^2(\tau) \left[ -d\tau^2 + (\delta_{ij} + 2\hat{E}_{ij})dx^i dx^j \right]$$First step is to figure out the connection coefficients, which are...
Can someone give me a better intuition of bandwidth.
The way I see it, is that the bandwidth is the range of frequencies which a signal/wave is allowed to have. This doesn't feel complete though.
For example, how can I explain that TDMA, FDMA and CDMA are similar in this sense. As far as I know...
I understand how waves undergo superposition. However, for a standing wave, the reflected wave is a mirror opposite of the incoming wave. By the superposition principle, won’t the 2 waves add up to 0, at all points?
Hi everyone, I m not a physicist and I don't really speak english... please forgive me if I write any "rubbish". I'm quite curious, and I was wondering how do electromagnetic waves travels. I mean, from a "point" source, they propagate in every direction (I've been told) so I tend to imagine...
At 0:51 in this simulation video there seems to be a brief moment upon merging that these singularities produce what appears to be negative gravitational "Spike?" that seems to bulge spacetime in an opposite metric compared to normal spacetime flatness. Is this a quirk of the simulation or is...
Good day to everyone,
I kindly ask for your help. My question is: "Does a string have to be under tension, to transmit longitudinal waves? Why is it so?" I have trouble finding relevant scientific articles regarding the question and for reasearching "longitudinal waves on a string". If anyone...
Points A b AND C are shown in first diagram
Im confused about question three... I feel like its related to wave length but the fractions are throwing me off.
Using this stimulation: https://phet.colorado.edu/sims/html/wave-on-a-string/latest/wave-on-a-string_en.html
It looks like frequency is decreasing as I increase tension but online it says frequency increases as tension does. Also, I am unsure about what happens to the Period
I think increasing the damping would decrease the amplitude and increase the Period (T). But, what I'm really unsure about is the frequency, wavelength and wave speed. Would it be no effect on those three? Because if dampening acts like friction, wouldn't it slow down the wave/ increase speed?
If we compare 2 scenarios... A) 2 solar mass black hole hyperbolic flyby of Earth at 5000km/s far enough not to cause a tidal disruption event vs B) an extremely close binary pair of 1 solar mass black holes whose barycenter hyperbolically travels past Earth at 5000km/s, also far enough not to...
Hi all, My question is about the attenuation and delay terms in part (1). what are attenuation and delay terms describing in physical phenomenon? thank you. What do "attenuation" and "delay" mean in terms of real-life physical phenomena?
Consider the wave equation for spherical waves in...
I know the answer would be yes, but why?
In class, I learned that energy is scalar and cannot be negative (at least in undergraduate class). Thus adding two sources of energy should result in a higher level of energy in general. But here for wave, if we have 2 waves that do destructive...
Hello everybody .
I would like to ask you for an opinion.
audio waves passing through a horn or waveguide experience a small or relatively large distortion.
do you think it is possible to eliminate distortion by making use of constructive interference?
Hello. I have a question related to capacitance.
here is another mechanical solution to harness wave energy.
Can changing capacity of the capacitor be used to harness wave energy?
Let's say we envelope conductive plates in plastic and submerge them
in the ocean and the water in between them...
Suppose some aliens travel to our solar system after seeing our radio broadcasts using an Alcubierre drive. Would it not create a notable gravitational disturbance? Or does it leave spacetime undisturbed around it?
Hi,
I have a question regarding oblique shockwaves.
Question: How can we determine what the wedge angle is for the shockwave in a situation?
Context: This problem here shows an oblique shock wave on the trailing edge of the body and it simply states that the wedge angle is 6 degrees. Why is...
I drew a diagram in the attached files as well, but the the scenario seems to be the same as the double slit experiment, but I don't understand why the answer contains cos instead of sin.
The waves of Nazaré start because of a storm in the open sea. The winds cause a disturbance on the surface, transformed into energy. When the depth is great, the propagation of the waves (energy) is practically constant. As they approach the coast, therefore in shallower places, the wave length...
Spacecraft heading to Uranus and Neptune in the next decade could be used to investigate gravitational waves as they venture into the outer Solar System. That is according to a new study by a team of Swiss and Danish researchers, who say that examination of the radio signals from far-flung...
I know that at the antinodes, the diffrence is pi radians and i got 0.25, 0.75, 1.25, and 1.75. for the position of antinodes. but the answer is x = 0.75 m, 1.25 m.
I can use drawing to obtain the answer, but my calculation gives me 0.25, 0.75, 1.25, and 1.75. Where am I doing wrong? Thanks!
Hi, I need help finding the phase difference between the two rays converging at F'.
I was given this figure, the distance between the lenses is 10cm, the thickness of the lense is 1micrometer and the indexes are on the figure. The light is a laser in which lamda = 500nm.
I tried to write down...
When I asked my professors about quantum interpretations like whether it is particles or waves in the double slit experiment. They always say it is just quantum stuff which is neither particles nor waves, so one must not describe them at such. So why do we have so many interpretations. Why not...
Let's assume a binary system with an inclination angle ##i## (angle between the orbital plane and line of sight). Then, according to this source - equations (128) and (129) - for the amplitudes of the tensor polarization modes ("plus": ##+## and "cross": ##\times## polarization) I could write...
Hello,
here's my question:
during the usual derivation of Fresnel's equations, it is assumed that an incident EM wave (plane monochromatic) is transverse electric or magnatic and that it keeps this nature after reflection and transmission.
How can this be proven?
Thank you!
I have a 2-dimensionsal smooth function ##f(x,y,t)##. There may be multiple traveling waves across the domain. None of them are precisely traveling waves (the shape of the wave changes as it travels). Here is how one of these waves would look in 1-dimension:
I want to find the speed of these...
Question: Can heavy objects be used to operate light waves with smaller amplitude, or waves with high amplitude be used to operate objects with small mass?
This is a diagram I drew that illustrates my point. Heavy objects are meant to be celestial bodies, and the light source generates a beam...
i am writing this message after a short consultation with kuruman. if there are two waves emitted by the same source then with the same direction, but these waves are in counterphase link...
Hey guys, I'm new to the physicsforums. I wanted to share some videos I made and see if anyone was interested or wanted to discuss what they see.
In this video I show in a manner in which is VERY easy to see, that a reflective surface will reflect not just light but also radio waves (and most...
Theta in the incident angle
Phi is the refraction angle
'' denotes everything that propagates to the other medium, that is, everything related to refraction
' denotes the reflection in the original medium
I am rather confused, would appreciate any help.
I see the second equation of TE is...
When studying classical mechanics we are told that light is the propogation of electromagnetic waves. This makes perfect sense, as I can imagine these fields behaving this way, and in turn have an associated wave length. When learning about QM, I have heard that the wavelength of a (any)...
I’m having A bit of confusion regarding this. In a plasma by turning on an electric field ,wouldn’t this cause an oscillation of the electrons about the ions,effectively a oscillating dipole thus inducing a magnetic field, by amperes law? My text (plasma physics by F.Chen )has curlE =0 I’m not...
My attempt:
p and T allows us to calculate ##Z=402 \frac{kg}{sm^2}## using ## Z=p*\sqrt(\frac{\gamma*M}{R*T})## . The sound intensity level at 10 meters allows us to calculate the intensity at 10 meters to be I=10``````^{-7} W/m^2 using ##50 = 10*log(I/I_0)##. Then, using the formula...
Consider the following thought experiment...
You are an engineer with a very peculiar assignment. With a mind to reduce the investment of excessive human labor and material waste, you have been asked to build an apparatus similar to an old-fashioned voicepipe. You are asked to ensure that the...
We have two different accepted formulas for the far field and near field respectively. I want a numerical program that works for both, furthermore I want to use it to calculate power through the aperture after confirming it in the far field vs near field.
I start off by treating the far field...
hi guys
i was trying to derive the general formula of two orthogonal waves
$$x^{2}-2xycos(δ)+y^{2} = A^{2} sin(δ)^{2}$$
where the two waves are given by :
$$x = Acos(ωt)$$
$$y = Acos(ωt+δ)$$
where ##δ## is the different in phase , i know it seems trivial but i am stuck on where should i begin...
Hello, this is an assigment form the 4th grade high school physics in Croatia, concerning electromagnetic waves.
Radio waves of wavelength 12m propagate from the source. The source is on the surface of the water and two waves propagate from it: one through the air and the other through the...