Posts Tagged ‘plasma’
Vacuum Tubes – Electronics at Work: 1943 Educational Film
In the classic educational film titled “Electronics at Work,” produced by Westinghouse in 1943, viewers are introduced to the fascinating world of vacuum tubes. This film highlights the crucial role these devices played in both military and commercial sectors, including radio telecommunications, radar, and various industrial applications. The narrative suggests that vacuum tubes provided the United States with a significant advantage during World War II, particularly in enhancing communication and technology.
The Continuing Relevance of Vacuum Tubes
Despite advances in technology, vacuum tubes remain in use today for several applications, including:
– Transmitting radios
– Medical devices
– Audio amplification systems
– High-frequency applications
Understanding Vacuum Tubes
The film outlines the six basic functions of electronic tubes and illustrates how each type is employed in different industrial and military contexts.
[embedyt] https://www.youtube.com/watch?v=ZJ6rN7WEjbc[/embedyt]
Structure of a Vacuum Tube
A vacuum tube typically consists of two or more electrodes housed within a vacuum inside an airtight enclosure. Key features include:
– Electrode Types: Most vacuum tubes have glass envelopes, although some utilize ceramic or metal casings with insulating bases.
– Leads and Sockets: The electrodes connect to leads that pass through the envelope via an airtight seal. These leads often take the form of pins, allowing for easy replacement in a tube socket, as tubes were a common point of failure in electronic devices.
– Capacitive Design: Some tubes feature a top cap on the electrode to minimize interelectrode capacitance, enhancing high-frequency performance and maintaining safety by separating high voltages.
The Evolution of Vacuum Tubes
The earliest vacuum tubes emerged from incandescent light bulbs, which contained a heated filament sealed in an evacuated glass envelope. When heated, the filament releases electrons into the vacuum through a process known as thermionic emission.
– Electrode Functionality: A second electrode, known as the anode or plate, attracts these electrons if it holds a more positive voltage. This mechanism results in a flow of electrons from the filament (cathode) to the plate, creating an electric field due to the potential difference between them.
– Diode Function: A vacuum tube with two electrodes is termed a diode, which functions as a rectifier. Diodes allow current to flow in only one direction, converting alternating current (AC) into pulsating direct current (DC). This technology is widely used in DC power supplies and in demodulating amplitude-modulated (AM) radio signals.
Film Availability and Production Details
This film is available in the public domain under Creative Commons, and it can be accessed through the Library of Congress Prelinger Archives. The film has been edited and converted to HD quality for better viewing. Introductory and closing music is provided by Nero 10, with commercial use rights granted.
This film not only serves as an educational tool but also highlights the enduring legacy of vacuum tube technology in the realm of electronics, illustrating its significant contributions to both past and present technological advancements.
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Stunning Ultra-HD View; Sun Timelapse 2015 NASA/SDO
This video is ten minutes of coolness.
This cool time-lapse video shows the Sun (in ultra-high definition 3840×2160 – 4k on YouTube) during the entire year, 2015. The video captures the Sun in the 171-angstrom wavelength of extreme ultraviolet light. Our naked, unaided eyes cannot see this, but this movie uses false-colorization (yellow/gold) so that we can watch in high definition.
The movie covers a time period of January 2, 2015 to January 28, 2016 at a cadence of one frame every hour, or 24 frames per day. This timelapse is repeated with narration by solar scientist Nicholeen Viall and contains close-ups and annotations. The 171-angstrom light highlights material around 600,000 Kelvin and shows features in the upper transition region and quiet corona of the sun.
The first half tells you a bit about the video and the Sun, and you can see the entire year 2015 rotate by. The second half is narrated by a NASA scientist. It is worth watching all ten minutes. And, then, sharing!
The sun is always changing and NASA’s Solar Dynamics Observatory is always watching.
Launched on Feb. 11, 2010, SDO keeps a 24-hour eye on the entire disk of the sun, with a prime view of the graceful dance of solar material coursing through the sun’s atmosphere, the corona. SDO’s sixth year in orbit was no exception. This video shows that entire sixth year–from Jan. 1, 2015 to Jan. 28, 2016 as one time-lapse sequence. Each frame represents 1 hour.
SDO’s Atmospheric Imaging Assembly (AIA) captures a shot of the sun every 12 seconds in 10 different wavelengths. The images shown here are based on a wavelength of 171 angstroms, which is in the extreme ultraviolet range and shows solar material at around 600,000 Kelvin (about 1 million degrees F.) In this wavelength it is easy to see the sun’s 25-day rotation.
During the course of the video, the sun subtly increases and decreases in apparent size. This is because the distance between the SDO spacecraft and the sun varies over time. The image is, however, remarkably consistent and stable despite the fact that SDO orbits Earth at 6,876 mph and the Earth orbits the sun at 67,062 miles per hour.
Why This is Important
Scientists study these images to better understand the complex electromagnetic system causing the constant movement on the sun, which can ultimately have an effect closer to Earth, too: Flares and another type of solar explosion called coronal mass ejections can sometimes disrupt technology in space. Moreover, studying our closest star is one way of learning about other stars in the galaxy. NASA’s Goddard Space Flight Center in Greenbelt, Maryland. built, operates, and manages the SDO spacecraft for NASA’s Science Mission Directorate in Washington, D.C.
For us radio enthusiasts, the study of the Sun helps us understand the dynamics of radio signal propagation. And, that aids us in communicating more effectively and skill.
Thanks for sharing, voting, and watching. More information and live Sun content can be accessed 24/7 at http://SunSpotWatch.com
You can also get the Space Weather and Radio Propagation Self-study Course at http://SunSpotWatch.com/swc
Five X-class (Major) X-ray Flares in a Row (plus more!)
Well, thankfully, this is not happening during this contest weekend: one of the largest sunspot regions during this Sunspot Cycle 24, and one of the biggest in several decades, gave us quite a show, back in October 2014.
Five major X-class (very strong) and a number of moderate and “mild” solar x-ray flares erupted from a single sunspot region – this video covers the time period of October 19-27, 2014, as captured by NASA’s SDO spacecraft. This is from what has been one of the biggest sunspot regions in a number of decades.
Between October 19 and October 27, 2014, a particularly large active region on the Sun dispatched many intense x-ray flares. This region, labeled by NOAA as Active Region (AR) number 12192 (or, simply, NOAA AR 12192, and shortened as AR 2192), is the largest in 24 years (at that point in Solar Cycle 24).
The various video segments track this sunspot region during this period (Oct. 19 – Oct.27, 2014), during which we can see the intense explosions. There are five X-class flares during this time, and NASA’s Solar Dynamics Observatory (SDO), which watches the sun constantly, captured these images of the event.
Solar flares are powerful bursts of radiation. Harmful radiation from a flare cannot pass through Earth’s atmosphere to physically affect humans on the ground, however — when intense enough — they can disturb the atmosphere in the layer where GPS and communications signals travel.
When referring to these intense solar eruptions, the letter part of the classification, ‘X’, means, ‘X-class’. This denotes the most intense flares, while the number, after the classification letter, provides more information about its strength. For example, an X2 is twice as intense as an X1, an X3 is three times as intense, and so forth.
Solar Images Credit: NASA’s Goddard Space Flight Center & SDO
http://SunSpotWatch.com ~ http://NW7US.us
73 de NW7US
An Amazing Moment in Space Weather – Massive Solar Eruption June 2011
While many are talking about how Solar Cycle 24 is the weakest since the Maunder Minimum (the period starting in about 1645 and continuing to about 1715 when sunspots became exceedingly rare, as noted by solar observers of the time — see this Wiki entry), there are moments when activity on the Sun strongly increases, providing brief moments of excitement.
Here is a case in point, witnessed by the Solar Dynamics Observatory (SDO; see SDO Mission) on June 7, 2011, when the Sun unleashed a magnitude M2 (a medium-sized) solar flare with a spectacular coronal mass ejection (CME). The large cloud of particles mushroomed up and fell back down looking as if it covered an area almost half the solar surface.
SDO observed the flare’s peak at 1:41 AM ET. SDO recorded these images in extreme ultraviolet light that show a very large eruption of cool gas. It is somewhat unique because at many places in the eruption there seems to be even cooler material — at temperatures less than 80,000 K.
This video uses the full-resolution 4096 x 4096 pixel images at a one minute time cadence to provide the highest quality, finest detail version possible. The color is artificial, as the actual images are capturing Extreme Ultraviolet light.
It is interesting to compare the event in different wavelengths because they each see different temperatures of plasma.
Credit: NASA SDO / Goddard Space Flight Center
Video: http://g.nw7us.us/1aOjmgA – Massive Solar Eruption Close-up (2011-06-07 – NASA SDO)
Visit: SunSpotWatch.com