جواب |
رسائل 1 من 620 في الفقرة |
|
martes, 20 de marzo de 2012
De izquierda a derecha: Galileo Galilei, Marie Curie, J. Robert Oppenheimer, Isaac Newton, Louis Pasteur, Stephen Hawking, Albert Einstein, Carl Sagan, Thomas Edison, Aristoteles, Neil deGrasse Tyson, Richard Dawkins y Charles Darwin.
|
|
|
أول
سابق
606 إلى 620 من 620
لاحق
آخر
|
جواب |
رسائل 606 من 620 في الفقرة |
|
|
|
جواب |
رسائل 607 من 620 في الفقرة |
|
In ‘Back to the Future’ (1985) you can see a portrait of Thomas Edison in Doc’s house when Marty travels back to 1955. This was a good prop to illustrate the time period, as no modern scientist like Doc would ever respect a degenerate conman like Edison.
https://www.reddit.com/r/shittymoviedetails/comments/getr2d/in_back_to_the_future_1985_you_can_see_a_portrait/?rdt=45765
In Back to the Future, Doc displays pictures of Newton, Franklin, Edison, and Einstein in his 1955 home while discussing time travel with Marty. All men whose work influenced Doc's invention.
https://www.reddit.com/r/MovieDetails/comments/c6n0bu/in_back_to_the_future_doc_displays_pictures_of/
|
|
|
جواب |
رسائل 608 من 620 في الفقرة |
|
In “Back To The Future” (1985), the portraits above Doc’s fireplace are (L-R) Isaac Newton, Benjamin Franklin, Thomas Edison, and Albert Einstein.
|
|
|
جواب |
رسائل 609 من 620 في الفقرة |
|
|
|
جواب |
رسائل 610 من 620 في الفقرة |
|
|
|
جواب |
رسائل 611 من 620 في الفقرة |
|
|
|
جواب |
رسائل 612 من 620 في الفقرة |
|
Subestación eléctrica de maniobras Magdalena I (Parque Solar Magdalena I)
NOVIEMBRE 17, 2021 PV MAGAZINE
Pirámide de la Espiral Xochitecatl, Tlaxcala
Fotografía: Gobierno del estado de Tlaxcala
La Dirección General de Impacto y Riesgo Ambiental de la Secretaría de Medio Ambiente y Recursos Naturales informa que ha recibido la documentación de la firma promovente Más Energía, para el proyecto de la Subestación eléctrica de maniobras Magdalena I (Parque Solar Magdalena I).
El proyecto consiste en la construcción, operación y mantenimiento de una subestación eléctrica de maniobras, dos accesos, y una línea eléctrica de entronque de 400 Kv que se interconectará a una línea de transmisión eléctrica existente de 400 Kv propiedad de la Comisión Federal de Electricidad para desahogar la energía eléctrica que se genera en la planta fotovoltaica parque solar Magdalena I al Sistema Eléctrico Nacional.
Este contenido está protegido por derechos de autor y no se puede reutilizar. Si desea cooperar con nosotros y desea reutilizar parte de nuestro contenido, contacte: editors@pv-magazine.com.
6 Schematic representation of a cyclotron. The distance between the pole pieces of the magnet is shown larger than reality to allow seeing what is inside
https://www.researchgate.net/figure/Schematic-representation-of-a-cyclotron-The-distance-between-the-pole-pieces-of-the_fig3_237993541
|
|
|
جواب |
رسائل 613 من 620 في الفقرة |
|
Subestación eléctrica de maniobras Magdalena I (Parque Solar Magdalena I)
NOVIEMBRE 17, 2021 PV MAGAZINE
Pirámide de la Espiral Xochitecatl, Tlaxcala
Fotografía: Gobierno del estado de Tlaxcala
La Dirección General de Impacto y Riesgo Ambiental de la Secretaría de Medio Ambiente y Recursos Naturales informa que ha recibido la documentación de la firma promovente Más Energía, para el proyecto de la Subestación eléctrica de maniobras Magdalena I (Parque Solar Magdalena I).
El proyecto consiste en la construcción, operación y mantenimiento de una subestación eléctrica de maniobras, dos accesos, y una línea eléctrica de entronque de 400 Kv que se interconectará a una línea de transmisión eléctrica existente de 400 Kv propiedad de la Comisión Federal de Electricidad para desahogar la energía eléctrica que se genera en la planta fotovoltaica parque solar Magdalena I al Sistema Eléctrico Nacional.
Este contenido está protegido por derechos de autor y no se puede reutilizar. Si desea cooperar con nosotros y desea reutilizar parte de nuestro contenido, contacte: editors@pv-magazine.com.
6 Schematic representation of a cyclotron. The distance between the pole pieces of the magnet is shown larger than reality to allow seeing what is inside
https://www.researchgate.net/figure/Schematic-representation-of-a-cyclotron-The-distance-between-the-pole-pieces-of-the_fig3_237993541
|
|
|
جواب |
رسائل 614 من 620 في الفقرة |
|
Chile and the Nazis : from Hitler to Pinochet / by Graeme S. Mount
|
|
|
جواب |
رسائل 615 من 620 في الفقرة |
|
|
, MA History, BA History
Jesus Christ had twelve disciples, each of whom accompanied the Biblical savior during His time on earth. Many of them continued His Christian work after the ascension. The twelve men were Peter, James (Jesus’ brother), John, Andrew, Philip, Judas Iscariot (who betrayed Jesus, and was replaced by Matthias), Matthew, Thomas, James, the son of Alpheus, Bartholomew, Judas Thaddeus; and Simon the Zealot. Of them all, Saint James, also known as James, brother of Jesus, James, son of Alpheus, James the Lesser, James the Minor, and James the Just, was one of the most prominent and significant.
James, Son of Alphaeus, James the Greater, and James, the Brother of Jesus
St James the Minor, Peter Paul Rubens, 1613. Source: Wikipedia
Various Gospels are often ambiguous, at times, as to which James is being referenced. Two to three James’s are spoken of in the Gospels – James, brother of John (aka James the Greater); James, brother of Jesus, and James, son of Alphaeus. The Catholic doctrine of the perpetual virginity of Mary holds that James the son of Alpheus and James, brother of Jesus are the same person, as James could not be Jesus’ physical full brother. In Protestant readings, the two are separate. If the two are separate, then very little is known regarding James, son of Alpheus.
James, Brother of Jesus
Statue of St. James the Less in the Archbasilica of St. John Lateran by Angelo de Rossi. Source: Wikipedia
James, the brother of Jesus, was a follower and Disciple of Jesus Christ during His earthly ministry and one of the first leaders of the early Christian Church. He remained in Jerusalem as leader of the church following the death, burial, resurrection, and ascension of Jesus, and was likely martyred at the temple in Jerusalem.
James’ Position in the Early Church
St. James the Minor, by Georges de la Tour, 1615-20. Source: Wikipedia
Get the latest articles delivered to your inbox
Sign up to our Free Weekly Newsletter
In Acts 15, a Council in Jerusalem was held regarding circumcision over which James presided. The Acts 15 Council is considered probably the first Christian council, where many Apostles congregated to discuss the matter brought by Paul and Barnabas. In Galatians 1, the Apostle Paul records a meeting with James in the process of Paul confirming his conversion to the other Apostles. James may have been the first elected leader within the early church. Through the writings of Eusebius in the 200s, we have the records of Clement of Alexandria from the second century that James was elected leader of the Jerusalem Church.
St James Was Martyred
Saint James the Less (Menologion of Basil II). Source: The Byzantine Life
The death of James the Just around 62 CE is recorded by Eusebius, Clement of Alexandria, and Josephus. Eusebius copied the chronicles of an earlier Christian, Hegesippus, who wrote that James was martyred by being thrown from the pinnacle of the temple in Jerusalem, and beaten with a club when the fall did not kill him.
Non-canonical Writings Attributed to Saint James
The Protoevangelium of James, James Orr. Source: Rakuten Kobo
The Gospel of James, also known as The Protoevangelium of James, is a book of unknown source that was being circulated within the second century church. Both Origen and Clement of Alexandria reference the book in their writings, so it was at least written around that time. The Gospel of James contains the first mention of the idea of the perpetual virginity of Mary, the mother of Jesus. The book was condemned by Pope Innocent I in 405, and it has generally not been accepted throughout church history as canonical due to its late writing and inconstant content.
The First and Second Apocalypse of James and the Apocryphon of James are other 2nd century books whose author claimed to be James. Each of these books were from a collection of gnostic (secret knowledge) texts found in Egypt in 1945. In addition to an authorship too late to be James, they are also part of gnostic texts written in an attempt to legitimize the early movement within Christianity.
James, the Son of Alphaeus
Two Martyr Saints in an Initial S (Alphaeus and Zacchaeus), 14th century. Source: Victoria and Albert Museum
James the son of Alphaeus, while mentioned in the listings of the apostles, has very few details known regarding his life. Outside of being listed among the apostles, and described in the Gospel of Mark as “the lesser” or “the smaller,” he is barely mentioned in the Bible. Several early Christian writings attempt to identify him with James the Just, but most try to maintain the perpetual virginity of Mary in a complex manner. It is speculated that he died as a martyr by crucifixion in Ostrakine, Egypt.
https://www.thecollector.com/who-was-saint-james-brother-of-jesus/ |
|
|
|
|
|
جواب |
رسائل 616 من 620 في الفقرة |
|
|
|
جواب |
رسائل 617 من 620 في الفقرة |
|
|
|
جواب |
رسائل 618 من 620 في الفقرة |
|
Wavelength to Frequency Calculation and Equation
A simple equation relates wavelength and frequency to the speed of the wave.
The wavelength to frequency and frequency to wavelength calculations are important in physics and engineering. Here is the equation relating wavelength and frequency, example calculations, and a table of common values.
Relationship Between Wavelength and Frequency
A simple equation relates wavelength to frequency:
v = λf
- v = wave velocity (how fast the wave propagates in a medium)
- λ = wavelength (distance over which a wave shape repeats)
- f = wave frequency (number of waves per unit of time)
For light and other electromagnetic radiation in a vacuum, the wave velocity is the speed of light (c):
c = λf
But, the wave speed is different for other kinds of waves and for light passing through a medium.
- Light in air or vacuum: 299,792,458 meters per second
- Light in water: 224,901,000 m/s
- Sound in air: 343.2 m/s
- Sound in water (20 °C): 1,481 m/s
Wavelength and frequency are inversely proportional. As wavelength increases, frequency decreases. As frequency increases, wavelength decreases.
How to Calculate Wavelength From Frequency
Rearrange the equation and calculate wavelength from frequency:
λ = v/f
For example, find the wavelength of the musical note A4, which has a frequency of 440 Hz.
The only tricky part in the calculation is keeping the units straight. Usually, you work with meters and Hertz and then convert to other units (e.g., nanometers, THz, GHz). In this problem, the wave velocity is the speed of sound in air (343.2 m/s). The frequency is 440 Hz. One hertz unit equal one cycle (wave) per second, so a frequency of 440 Hz is 440 s-1.
λ = v/f λ = (343.2 m/s)/(440 s-1) λ = 0.78 m or 78 cm
As another example, find the frequency of the green light of the aurora borealis, which has a frequency of 5.38 x 1014 Hz.
Here, the equation is:
λ = c/f λ = (3 x 108 m/sec)/(5.38 x 1014 s-1) λ = 5.576 x 10-7 m = 557.6 nm
How to Calculate Frequency From Wavelength
Rearrange the equation and calculate frequency from wavelength:
f = v/λ
For example, find the wavelength of orange light with a frequency of 4.8×1014 Hz.
f = v/λ (but v is c for light) f = c/λ f = (3.00 × 108 m/s)/(4.8×1014 s-1) f = 6.2 x 10-7 m = 620 nm
Wavelength to Frequency Chart
This chart shows the wavelength to frequency relationship for electromagnetic radiation:
Electromagnetic Radiation |
Wavelength |
Frequency |
Gamma radiation |
1 pm |
300 EHz |
X-ray |
1 nm |
300 PHz |
Ultraviolet |
100 nm |
3 PHz |
Visible light |
400-700 nm |
430-750 THz |
Infrared |
100 μm |
3 THz |
EHF (Extremely high frequency) |
1 mm |
300 GHz |
SHF (Super high frequency) |
1 cm |
30 GHz |
UHF (Ultra high frequency) |
1 dm |
3 GHz |
VHF (Very high frequency) |
10 m |
30 MHz |
ELF (Extremely low frequency) |
100,000 km |
3 Hz |
References
- Avison, John (1999). The World of Physics. Nelson Thornes. ISBN 978-0-17-438733-6.
- Cassidy, David C.; Holton, Gerald James; Rutherford, Floyd James (2002). Understanding Physics. Birkhäuser. ISBN 0-387-98756-8.
- Hecht, Eugene (1987). Optics (2nd ed.). Addison Wesley. ISBN 0-201-11609-X.
https://sciencenotes.org/wavelength-to-frequency-calculation-and-equation/ |
|
|
جواب |
رسائل 619 من 620 في الفقرة |
|
|
|
جواب |
رسائل 620 من 620 في الفقرة |
|
|
|
أول
سابق
606 a 620 de 620
لاحق
آخر
|