OpenLLM-France/wikimedia huggingface dataset:
# A-level Physics/Health Physics/Transport Phenomenon

* In physics, chemistry, biology and engineering, a transport phenomenon is any of various mechanisms by which particles or quantities move from one place to another.
* The laws which govern transport connect a flux with a "motive force".
* Three common examples of transport phenomena are diffusion, convection, and radiation.
# A-level Physics/Nuclear and Particle Physics
## Contents

* The Nucleus
* Neutrons And Fission
* Fusion
* Matter and Antimatter
* Fundamental Particles
# A-level Physics/Printable version

The current, editable version of this book is available in Wikibooks, the open-content textbooks collection, at
https://en.wikibooks.org/wiki/A-level_Physics

# Edexcel (Salters Horners)

This Wikibook is about A-level Physics, designed to follow the Edexcel (Salters Horners) syllabus, but is not endorsed by Edexcel. It will hopefully be useful as a revision guide or for alternative explanations to the ones in your textbook or from your tutor.

## AS Units
### PSA1: Physics at work, rest and play (6751)

* Higher, Faster, Stronger (HFS)
* Good Enough to Eat (EAT)
* Spare Part Surgery (SUR)

### PSA2: Physics for life (6752)

* Digging Up the Past (DIG)
* Technology in Space (SPC)
* Sound of Music (MUS)

### PSA3: Coursework (6753)

* Experimental skills
* Visit

## A2 Units
### PSA4: Physics on the Move (6754)

* Transport on Track (TRA)
* The Medium is the Message (MDM)
* Probing the Heart of Matter (PRO)

### PSA5i: Coursework (6755/01)

* Practical project

### PSA5ii: Physics from creation to collapse (6755/02)

* Build or Bust? (BLD)
* Reach for the Stars (STA)

### PSA6: Synoptic test (6756)
## External links

* University of York course website
* Edexcel (Salters Horners) Advanced GCE in Physics — Specification, Issue 3 October 2003
* Edexcel Salters Horners A-level Physics resources
# A-level Physics/Health Physics/The Ear and Hearing

The ear is the organ responsible for the sense of hearing and also plays a crucial role in maintaining balance and spatial orientation. Hearing is the process by which sound waves are detected, transformed into electrical signals, and interpreted by the brain as sound.
Anatomy of the Ear:
The ear is divided into three main sections: the outer ear, the middle ear, and the inner ear.
Process of Hearing:
Balance and Spatial Orientation:
In addition to hearing, the inner ear's vestibular system is responsible for detecting motion, gravity, and changes in head position. This information is vital for maintaining balance, coordination, and a sense of spatial orientation.
The ear's intricate structure and the complex process of hearing allow us to perceive and interpret a wide range of sounds, from soft whispers to loud music, and contribute to our overall understanding of the world around us.

## External Resources

* Sensory Systems
# A-level Physics/Wave Properties
## Contents

* Reflection and Refraction
* Waves
* Superposition
# A-level Physics/Telecommunications

Electronic signals Communication Principles Digital Systems Amplifliers Radios Optic Fibres Systems and Networking
a useful site
# A-level Computing/AQA/Paper 2/Fundamentals of data representation/Information coding systems/Error checking and correction

A parity bit is a method of detecting errors in data during transmission. When sending data, it is sent as a series of 0s and 1s.
In the figure above, a Unicode character is transmitted as the binary code 0111000110101011. It is quite possible that this code could get corrupted as it passed around either inside the computer or across a network.
In the top example the parity bit is set to 0 to maintain an even number of ones. One method for detecting errors is to count the number of ones in each byte before the data is sent to see whether there is an even or odd number. At the receiving end, the code can be checked to see whether the number is still odd or even.

## Majority voting

Majority voting is another method of identifying errors in transmitted data. In this case each bit is sent three times. So the binary code 1001 would be sent as:
111000000111.
When data is checked, patterns of three bits are usually seen. In this case, it is 111 for the first bit, then 000 and so on. Where there is a discrepancy, majority voting indicates which bit occurs the most frequently. For example, if the same code 10001 was received as:
101010000111.
Assume that the first bit should be 1 as two out of three of the three bits are 1 and assume that the second bit is 0 as two of the three bits are 0. The last two bits are 0 and 1 as there appears to be no errors in this part of the code.

## Check digits

Like a parity bit, a check digit is a value that is added to the end of a number to try and ensure that the number is not corrupted in any way. The check digit is created by taking the digits that make up the number itself and processing them in some way to create a single digit. The simplest but most error-prone method is to add the digits of the number together, and keep on adding the digits until only a single digit remains.
So the digits of 123456 add up to 21 and 2 and 1 in turn add up to 3, so the number with its check digit becomes 1234563. When the data is being processed the check digit is recalculated and compared with the digit that has been transmitted. Where the check digit is the same then it is assumed that the data is corrected. Where there is a discrepancy, an error message is generated.
# A-level Computing/AQA/Paper 2/Fundamentals of data representation/Nyquist-theorem

We have seen the various ways that you can reduce the size of files, we have also seen that humans have a limit to the frequencies that they can perceive, so what sampling rate would be needed to only store the samples that humans can perceive. The full range of human hearing is between 20 Hz and 20 kHz.
* Extension: Human hearing limit
* People are able to hear different frequencies, up to what level can you hear?
* For x = 0 To 25
* Console.WriteLine("Can you hear: " & x * 1000 & "Hz?")
* Console.Beep(x * 1000, 500)
* Next
* You lose your hearing with age, so the older you are the less likely you are to be able to hear the full spectrum.
So why not just use 20 kHz as our sampling rate record 20k cycles per second and be done with it? There is a small problem:
What we need to properly represent a sound wave is to sample it at least two times per cycle:
Therefore the minimum sampling rate that satisfies the sampling for the human ear is 40 kHz (2*20 kHz). The 44.1 kHz sampling rate used for Compact Disc was chosen for this and other technical reasons.
Shannon's version of the theorem states:
   If a function x(t) contains no frequencies higher than B Hz, it is completely determined by giving its ordinates at a series of points spaced 1/(2B) seconds apart.
We can relate Frequency and period together using this equation. This equation will be very useful for working out the sample rate of a given wave.
What happens when you have a graph of time against displacement? We know that Nyquist's Theorem is that the sample rate should be double than the highest frequency. So to calculate the sample rate,
* Work out the period by looking at the time taken for one complete oscillation.
* Work out the frequency
* Work out the sample rate with this:
* Exercise: Nyquist-theorem
* Describe Nyquist's-theorem
* Answer:
* You should set the sample rate at a frequency which is at least twice the value of the highest frequency in the sampled signal
* For a sound sample of maximum frequency 16 kHz what should the sample rate be?
* Answer:
* 32 kHz
* How many cycles per second in the following sample?
* For the sample what should the sample rate be according to nyquist's-theorem?
* Answer:
* the sample has a frequency of 4 cycles per second. using Nyquist's theorem you would have to sample this at at least 8 Hz

## References

* ↑ C. E. Shannon, "Communication in the presence of noise", Proc. Institute of Radio Engineers, vol. 37, no. 1, pp. 10–21, Jan. 1949. Reprint as classic paper in: Proc. IEEE, vol. 86, no. 2, (Feb. 1998)
# A-level Computing/AQA/Paper 2/Fundamentals of data representation/Images

A large part of using modern computers involves sending pictures and films to each other, along with using a graphical user interface. All of this involves computers saving and processing images. This section will cover the two main image types: vector and bitmap, along with some compression techniques.
# Animal Behavior/Endocrinology
## The Glandular Systems

The body has to types of glandular systems, the endocrine, which generally secrete hormones through the bloodstream, and the exocrine which secrete fluids to the outer surfaces of the body, such as sweating.
# Animal Behavior/Eusociality
## Sociality and Eusociality

Social behavior: Behavior that relates to interactions with other members of the population. Pros/cons of group living. <Society> a group of individuals of the same species that is organized in a cooperative manner extending beyond sexual and parental care.
Group Living, altruism, coorperative behaviors may emerge if genes for such characteristics are favored. This may occur under different circumstances
Egoistic solutions: selfish herd; Mutualism although the behaviour may seem altruistic, individuals benefit directly (e.g. living in a group and co-operating with others directly benefits the individual because of the general advantages of group living). Reciprocal altruism where the benefits accrued to the individual exceed the costs it incurs Kin selection when behavior sufficiently enhances the fitness of related individuals (i.e., carrying similar genes) leading to an increased representation of genes being passed on to the next generation Eusociality: an extreme form of altruism where sterile workers labor on behalf of reproductive individuals, cooperation in the care of young. There must be an overlap of at least two generations of individuals which share in colony labor.
Inclusive Fitness: refers to the sum of an individual's <Direct Fitness> (probability of reproductive success of one's own offspring) and its <Indirect Fitness> (probability of reproductive success of non-descendant relatives). Altruistic acts are frequently directed towards relatives. <Kin Selection>: selection for traits that lower an individual's personal fitness, but raise a relative's fitness. Recipient (related) kin share genes with the altruistic individual and are thus genetic extensions of them. Kin selection and inclusive fitness can explain sociality through increased survivorship of relatives, increased inclusive fitness, altruism, and delayed maturation or breeding.
Hamilton's Rule benefit to recipient / cost to altruist > 1 / coefficient of relatedness
# Animal Behavior/Definition
## Animal Behavior

Animal Behavior is the scientific study of the wild and wonderful ways in which animals interact with each other, with other living beings, and with the environment. It explores how animals relate to their physical environment as well as to other organisms, and includes topics such as how animals find and defend resources, avoid predators, choose mates, reproduce, and care for their young-ones.
Previous lesser definitions of Animal Behavior include:
* "Behavior is motion". "Movement, not necessarily movement of the whole animal... muscular contractions" or "The whole function of the nervous system can be summed up in one word, conduction." - In Sherrington's view, the basic elements of behavior was formed in a reflex-arc, where receptor organs receive sensory stimuli and are conducted to an effector organ. This highly reductionist position has received criticism from many angles, specifically, from arguments that it fails to account for spontaneous behaviors, behaviors that are characterized by a lack of motion, as well as disregarding the complexity of emergent properties in behavior.
* "What a plant or animal does, in the course of an individual's lifetime, in response to some event or change in its environment." - This definition reduces behavior to phenotypic plasticity and is thus not specific enough.
* "Behavior is all observable or otherwise measurable muscular and secretory responses (or lack thereof) and related phenomena in response to changes in an animal's internal or external environment.” Behavior may include components which do not lend themselves to simple quantification.
* "Behavior is characterized by entropic and energetic transductions by an organism, in which the long-term averages convert high entropic and low energetic sensory inputs into low entropic and high energetic outputs." - This definition is too incomprehensible to be of great use.

### References

* ↑ Sherrington CS. 1899. On the Spinal Animal (The Marshall Hall Lecture). Medico-Chirurgical Transactions, London 82: 449-477
* ↑ Silvertown J & D Gordon, 1989. A framework for plant behavior. Annual Review of Ecology & Systematics, 20, 349-366
* ↑ Grier JW & T Burk, 1992. Biology of Animal Behaviour. Mosby Year Book, St. Louis
* ↑ Hailman JP. 1977. Optical Signals: Animal Communication and Light. Indiana Univ Press, Bloomington
<<Return to Contents Page |<<Chapter 1
# Adventist Youth Honors Answer Book/Music/Note duration

The names of the types of notes come from the fraction of a measure that each note gets in bar of music in four four time. In the 4/4 time signature, the top 4 indicates how many beats are in each bar of music, and the lower 4 indicates that a quarter note gets one beat. Since four quarter notes would fill the entire bar, they are called quarter notes. A half note would get two beats, or ½ of the measure, and a whole note gets 4 beats or the whole measure.
Quarter notes have a solid note head with a stem attached.
Half notes have a hollow note head with a stem attached.
Whole notes have a hollow note head, but no stem at all.
# Adventist Youth Honors Answer Book/Natural dyes

Gather your plants from an area where the species you are after is abundant. Be sure to not take more than two-thirds of the plants from any one area. Natural fabrics work best with natural dyes, so choose cotton or wool (you can use yarn if you like).
The amount of material needed for the dyepot varies. For four ounces of cloth or yarn, use 12 ounces of plant material, one ounce of alum, and 1/4 ounce of cream of tartar in four quarts of water. Soak skeins of white yarn or material in plain water for 24 hours before dyeing.
Create Dye
* Put water in a large pot, add shredded plant parts (place in net bag)
* Simmer 1/2 to 1 hour (just below the boiling point)
* Strain out material (remove net bag)
Dye Fibers
* Add alum and cream of tartar to water and stir (cream of tartar helps keep fibers soft)
* Put in pre-moistened fiber/yarn
* Simmer until material is a little darker than you desire, stirring and submerging occasionally
* Remove from heat
Remove Fibers from Bath and Dry
* Rinse (starting with warm water) until cool
* Hang to dry
Be sure to wash the cloth by itself the first time you launder it. The last thing you want to do is accidentally dye your other clothes!
# Adventist Youth Honors Answer Book/Music/Intervals

A half-tone - Semi-tone
A semitone, also called a half step or a half tone, is the smallest musical interval commonly used in Western tonal music, and it is considered the most dissonant when sounded harmonically. It is defined as the interval between two adjacent notes in a 12-tone scale. For example, C is adjacent to C♯; the interval between them is a semitone.
Whole tone
Whole-tone scale, in music, a scalar arrangement of pitches, each separated from the next by a whole-tone step (or whole step), in contradistinction to the chromatic scale (consisting entirely of half steps, also called semitones) and the various diatonic scales, such as the major and minor scales (which are different arrangements of whole and half steps).
A third
In classical music from Western culture, a third is a musical interval encompassing three staff positions, and the major third is a third spanning four semitones.
A fifth
In music theory, a perfect fifth is the musical interval corresponding to a pair of pitches with a frequency ratio of 3:2, or very nearly so.
An octave
In music, an octave (Latin: octavus: eighth) or perfect octave is the interval between one musical pitch and another with half or double its frequency. It is defined by ANSI as the unit of frequency level when the base of the logarithm is two.
# Adventist Youth Honors Answer Book/Music/Orchestra

The modern definition of the word Orchestra tends to refer to the ensemble of mixed instrumentalists playing classical music. When you think of an orchestra, you imagine seventy or eighty or more musicians dressed in black on stage. This was not always the case.
In the musical time period known as Renaissance times (1450–1600) these musical groups not only accompanied vocal music, but played supporting music for drama. Ensembles playing this music were formed from instruments as varied as the harpsichord, viol, lute, recorder, cornett, sackbut, and organ.
The orchestras seen in the Baroque period (1600–1750) began to get bigger. Previous to this, vocal music was the most important music, and instrumental music was less so. The ability of the craftsmen to build instruments had improved to the point that the finest violins ever built were made around this time.
The orchestra of this time centered around the harpsichord. A harpsichord was like the piano of today, except a mechanical pick plucked the strings like a guitar, rather than a hammer hitting the strings like a piano. Violins, violas, cellos, and bass violins provided string sounds. Woodwind instruments like recorders, flutes, bassoons, and oboes, added color to the sound. Trumpets were used in orchestras as well, but were long natural trumpets without the more modern invention of valves. The timpani was the main percussion of the period.
Orchestras of the Baroque period were small by modern standards, numbering only about twenty to thirty players.
The next musical period is called the Classical period (1750–1825). During this period the orchestra grew to include 30-40 players. The brass section grew to include horns and trombones. Woodwinds included piccolos, clarinets, and contra bassoons (bass).
The Romantic musical period (1820–1900) brought new changes to the orchestra and it's instruments. The industrial revolution allowed for technical advances in the fabrication of instruments, especially the brass section with the invention of valved instruments. This allowed composers much more freedom in the parts they could write for all the instruments.
The tuba, bass clarinet, and many percussion instruments were added. This required additional string players to make the orchestra sound balanced. In his Symphony of a Thousand, Mahler had wrote for an orchestra containing one hundred and thirty musicians so it is clear to see with what enthusiasm composers explored the limits of possibility.
A current, professional symphony orchestra usually contains about seventy or eighty instrumentalists selected to fill the four sections of a modern orchestra; Brass, Woodwind, String, and Percussion. This will vary depending on the music being performed.

## Brass Instruments

* Horn
* Trumpet
* Trombone
* Bass Trombone
* Tuba

## Woodwinds

* Flute
* Piccolo
* Oboe
* Cor anglais
* Clarinet
* Bass Clarinet
* Bassoon
* Contrabassoon

## Strings

* Harp
* Violin
* Viola
* Cello
* Double Bass
* Piano

## Percussion

* Timpani
* Snare Drum
* Bass Drum
* Celesta
# Adventist Youth Honors Answer Book/Music/March waltz

'Waltz', or valse from the German term, is a piece of music in triple meter, most often 3/4 but sometimes 3/8 or 6/4. A waltz has a 1.2.3. - 1.2.3. count and (generally) a slow tempo. Waltzes typically have one chord per measure, with the root of the chord as the first note.
Classical composers traditionally supplied music for dancing when required, and Schubert's waltzes were written for household dancing, without any pretense at being art music. However, Chopin's 19 waltzes (five he wrote as a child), along with his mazurkas and polonaises, were clearly not intended to be danced to. They marked the adoption of the waltz and other dance forms as serious composition genres.
Other notable contributions to the waltz genre in classical music include 16 by Brahms (originally for piano duet), and Ravel's Valses nobles et sentimentales for piano and La Valse for orchestra.
The waltz style is found in nearly every kind of European and Euro-American folk music and also in classical music. Although waltzes are often associated with the dance of the same name, not all waltzes were composed as dances: some were written for concert performance.
The waltz had once held so much importance in European music circles that great waltz composers received the honorary title of “Waltz King”. The title came with an accompanying “royal staff”, a decorated silver baton which was passed from musician to musician. Johann Strauss Junior, the most famous “Waltz King”, received the title frequently.
# Adventist Youth Honors Answer Book/Music/Schubert
## Schubert, Franz (1797 – 1828)

* The son of a schoolmaster, he showed an extraordinary childhood aptitude for music, studying the piano, violin, organ, singing and harmony.
* Schubert composed symphonies and chamber music, but is best known for composing over six hundred Lieder (German for “songs”).
* These songs were composed as a vocal solo with piano accompaniment.
* Many were written using the words of existing poets and poems in this time period. The musics melody and accompaniment were written with an attempt to portray the themes and ideas of the poetry in music as well.
* One of Schubert's famous songs is called der Erlkönig, which is written to an eerie poem by Goethe, based on a legend in which anyone who is touched by the king of the elves will die (der Erlkönig is German for the elf king).
* The way that Schubert wrote the music to portray the poem is very interesting. The piano sounds the horses hooves at a gallop while the singer sings the voices of the characters in the poem. This song is often listed as an example of this type of music.
# Adventist Youth Honors Answer Book/Music/Other composers
## Many more composers articles have been written for wikipedia.

The Composers category in Wikipedia lists composers grouped by musical era.
# Adventist Youth Honors Answer Book/Music/Scales

Scales are an important building block of music. They are the basis of melodies and chords. Without knowing your scales, you are like a car mechanic without his tools.
What are scales? A good way to define a scale is to list the following characteristics:
* A scale is an organized series of pitches
* A scale utilizes sharps and flats, when necessary
* A scale consist of a series of notes that differ in sound
* A scale is linked to the concept of "Keys" in that a song which utilizes a given scale is said to be in that key (For example: "Mary had a little lamb in C major").
A major scale has 8 tones. The (C major scale) is: C-D-E-F-G-A-B-C.
These notes in the major scale form a pattern of steps between notes called whole tones, or semitones. On a piano keyboard semitones are from key to key with no keys in between, whole tones always skip a key with one key in between.
The major scale is made up of a pattern of two whole tones, followed by a semitone, followed by three whole tones, ending with one more semitone.
This illustration shows the difference between whole tones and semitones on a piano keyboard.
Notice how the whole tones skip a key on the keyboard, and semitones do not. Also you can see that two semitones makes up a whole tone. Whole tones and semitones are types of intervals.
The natural minor scale has a whole tone semitone pattern of whole tone, semitone, whole tone, whole tone, semitone, whole tone, whole tone.
Other scales such as melodic minor, harmonic minor, pentatonic, and whole tone have different patterns of whole tones and semitones.