#retroreflectors

[scribblewise]

Do your own reseaarch

[dogstomp]

Dogstomp #3154 - August 20th

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[doyoulikethissong-poll]

Fiona Apple - Criminal 1997

"Criminal" is a song by American singer-songwriter Fiona Apple, the third single from her debut studio album, Tidal. Apple has stated that the song is about "feeling bad for getting something so easily by using your sexuality". Apple's highest-charting single, it peaked at number 21 on the Billboard Hot 100, as well as number 4 on the Billboard Modern Rock Tracks. The song won the Grammy Award for Best Female Rock Vocal Performance at the 40th Grammy Awards and was nominated for Best Rock Song. "Criminal" was listed at number 55 on VH1's "100 Greatest Songs of the '90s", and number 71 on Blender magazine's 2005 list of "The 500 Greatest Songs Since You Were Born".

The music video was directed by Mark Romanek with cinematography by Harris Savides. Visual enhancements including the retroreflector in Fiona's eyes and additional lighting vignettes were created by visualist Ash Beck. In 1998, the video won an MTV Video Music Award for Best Cinematography. The video was featured in the 1997 MTV special "Beavis and Butt-Head Do Thanksgiving". Up until Beavis and Butt-Head's revival in 2011, it was the last to be critiqued by the duo among other videos in the special. In the second episode of American Horror Story: Freak Show, Bette and Dot Tattler perform a duet version of "Criminal".

"Criminal" received a total of 74,8% yes votes!

[yellowballoonx]

[buttons-beads-lace]

@mcnamak said: please explain! I love lasers

All right! So! As we know, the distinctive thing about lasers, what makes them different from flashlights, is that their light is all synced up. It stays together instead of getting dimmer and more spread out as it travels. When you shine your laser at a wall, it makes a neat little dot whether the wall is near or far.

If you have a good enough laser, you can even shine it at the moon, and across those roughly 240,000 miles it will still hit a... relatively smallish spot, if it's a good laser. That's a long way.

Ok but why would you want to shine a laser at the moon?

Well, when the Apollo missions went to the moon, they did a lot of science, they gathered a lot of samples of moon rock and so forth, and one of the things they did was to leave an array of mirrors on the moon.

The mirrors aren't that big, really. But if you can aim a powerful laser at exactly the right spot, you can hit those mirrors. And if you have the right kind of telescope, you can see that laser light get reflected and travel those 240,000 miles right back to you.

And that is actually how we measure the distance between Earth and the moon!

You can look up "lunar laser ranging experiments" on Wikipedia for more info.

Hey speaking of lasers

Do y'all know about how you can use a laser to prove the moon landing was real?

[feelingautistic]

Shark Senses: Sight

Contrary to popular belief, sharks do not have poor eyesight although generally sight is not a shark's primary sense when taking in information about their surroundings. Sharks can only see well up to about 15m (50ft) so sight is generally only used once a shark has locked onto prey using its other senses.

Sharks also have an additional layer on their eyes called the tapetum lucidum made up of mirrored crystals which functions as a retroreflector, reflecting light back through the retina. This increases the available light able to be picked up by photoreceptors and, as a result, sharks can see particularly well in low-light conditions (sharks can see about 10 times better in dim lighting than humans). Cats also have a tapetum lucidum.

[gremlins-hotel]

ayo grem do you think Nation cells work a bit like HeLa cells on crack.

and by eye shine do you mean how cat's eyes shone because of that teptum ludicium something film behind their eyes, cause ngl that would be cool, and terrifying

gonna be real heam i uh,,, don't know what hela cells are. cells and virology and stuff is way outta my wheelhouse but it is interesting.

and yes! by eye shine i mean the phenomenon we observe from animals with a tapetum lucidum, i.e., cows, cats, deer, dogs, alligators. while humans get "eye shine" (the red-eye effect) in flash photographs, this is due to the fundus in our eye, not a tapetum lucidum. and if you know anything about a tapetum lucidum, it's a reflector; it lies behind the retina and bounces light back through it, which is the reason behind superior night vision in many animals. when you see the eyes of your dog or cat flash green/blue/etc., it is that retroreflector interacting with the angle of your view and the available light of the area bouncing off of it. while your pet has a fundus too, which will also produce a red-eye effect in photos, eye shine can be multitude of colors depending on eye color, retinal structure, angle of light, etc. it also usually varies by species (some people use this to id animals at night, such as alligators typically having a reddish-orange to pink shine). another fun fact: individuals with heterochromia might have two different colors of eye shine!

i like to think the nations have a retroreflector like this. idk why, it just makes them inhuman enough that it's creepy and fun. but in low light, you might see one turn their head and their pupils might flash a sickly green or yellow if the angle is right. they have a hard time sneaking up on each other this way, even in the dark.

[hidden-lore-world]

Progress Update 11/10/2024

Haven't made a progress update in a bit, but want to keep documenting changes and interations even if they are small. So here we go.

The majority of the focus recently has been on developing the Viewfinder for the Interpreter. One of the major pieces of design I want to incorporate into this is a 3D viewing space, akin to a hologram/projection/Pepper's Ghost. My original plan for this was to modify this design. I saw this concept about a decade ago on Instructables I think and thought it was really cool.

My modifications were going to be using four separate OLED displays each running either the original or a mirrored or rotated version of the original gif/movie/image, rather than a single screen with the four images on it together. There were some pros and cons of this I had convinced myself of, but one of my barriers on progress in this method was related to having the Arduino I am working with not having enough breakout pins for the type of data pins I need for four screens. My soldering skills aren't amazing, so getting four of them hooked into one set of pins was daunting.

However, I found this video a few days ago, and was reintroduced to Retroreflectors. Video goes over the basics of the tech, and even takes it a step further by introducing ways to make it into a "touch screen". However, that's extra complexity and not what I want for this Viewfinder anyway, so it's possible I can just snag the reflector part of their build and significantly reduce the complexity in my own design.

This now leaves potential for a much larger image size, as before I was limited to 128 x 64 pixels, as I wanted to keep the footprint small, which majorly limited screen size to fit with needing to cram four into the space. So bigger canvas size is great! Fewer electrical components is also great! Now is just getting in some sample materials for testing the holographic display part itself.

Another part of the project I've been working on is the music. Less progress here, but I have started to tinker with a program to add in drums which I think will add a much-needed layer to the music I have been working on.

That's all for this one, I am hoping to have materials in a couple weeks, and I am clearing out some sidejobs that also will help fund this endeavor.

[spacefrontier]

Edwin "Buzz" Aldrin unpacks EASEP (Early Apollo Surface Experiments Package) experiments from LM Eagle. July 20, 1960

Due to the risk of an early abort on the Moon, geologists persuaded NASA to permit only experiments that could be set up or completed within 10 minutes. As a result, Apollo 11 did not carry a full ASLEP package, leaving a simpler version called EASEP. The EASEP included a Laser Ranging Retroreflector (LRRR), and Passive Seismic Experiment Package (PSEP), which was sensitive enough to pick up Armstrong and Aldrin's footfalls on the lunar surface.

LRRR on the lunar surface. Apollo 11's LRRR is still used today to measure distance to the Moon from Earth.

Aldrin standing next to the assembled PSEP.

Project Apollo Archive

[josiewalnuts]

to a retroreflector, you are the center of the universe <3

[spacenutspod]

A SpaceX Falcon 9 rocket carrying Intuitive Machines’ Nova-C lunar lander lifts off from Launch Pad 39A at NASA’s Kennedy Space Center in Florida at 1:05 a.m. EST on Feb. 15, 2024. As part of NASA’s CLPS (Commercial Lunar Payload Services) initiative and Artemis campaign, Intuitive Machines’ first lunar mission will carry NASA science and commercial payloads to the Moon to study plume-surface interactions, space weather/lunar surface interactions, radio astronomy, precision landing technologies, and a communication and navigation node for future autonomous navigation technologies. A suite of NASA science instruments and technology demonstrations is on the way to our nearest celestial neighbor for the benefit of humanity. Through this flight to the Moon, they will provide insights into the lunar surface environment and test technologies for future landers and Artemis astronauts. At 1:05 a.m. EST on Thursday, Intuitive Machines’ Nova-C lander launched on a SpaceX Falcon 9 rocket from Launch Complex 39A at the agency’s Kennedy Space Center in Florida. At approximately 1:53 a.m., the lander deployed from the Falcon 9 second stage. Teams confirmed it made communications contact with the company’s mission operations center in Houston. The spacecraft is stable and receiving solar power. These deliveries are part of NASA’s CLPS (Commercial Lunar Payload Services) initiative and Artemis campaign, which includes new solar system science to better understand planetary processes and evolution, search for evidence of water and other resources, and support long-term human exploration. “NASA scientific instruments are on their way to the Moon – a giant leap for humanity as we prepare to return to the lunar surface for the first time in more than half a century,” said NASA Administrator Bill Nelson. “These daring Moon deliveries will not only conduct new science at the Moon, but they are supporting a growing commercial space economy while showing the strength of American technology and innovation. We have so much to learn through CLPS flights that will help us shape the future of human exploration for the Artemis Generation.”  While enroute to the Moon, NASA instruments will measure the quantity of cryogenic engine fuel as it is used, and during descent toward the lunar surface, they will collect data on plume-surface interactions and test precision landing technologies. Once on the Moon, NASA instruments will focus on investigating space weather/lunar surface interactions and radio astronomy. The Nova-C lander also will carry retroreflectors contributing to a network of location markers on the Moon for communication and navigation for future autonomous navigation technologies. NASA science aboard the lander includes: Lunar Node 1 Navigation Demonstrator: A small, CubeSat-sized experiment that will demonstrate autonomous navigation that could be used by future landers, surface infrastructure, and astronauts, digitally confirming their positions on the Moon relative to other spacecraft, ground stations, or rovers on the move. Laser Retroreflector Array: A collection of eight retroreflectors that enable precision laser ranging, which is a measurement of the distance between the orbiting or landing spacecraft to the reflector on the lander. The array is a passive optical instrument and will function as a permanent location marker on the Moon for decades to come.    Navigation Doppler Lidar for Precise Velocity and Range Sensing: A Lidar-based (Light Detection and Ranging) guidance system for descent and landing. This instrument operates on the same principles of radar but uses pulses from a laser emitted through three optical telescopes. It will measure speed, direction, and altitude with high precision during descent and touchdown.    Radio Frequency Mass Gauge: A technology demonstration that measures the amount of propellant in spacecraft tanks in a low-gravity space environment. Using sensor technology, the gauge will measure the amount of cryogenic propellant in Nova-C’s fuel and oxidizer tanks, providing data that could help predict fuel usage on future missions.    Radio-wave Observations at the Lunar Surface of the Photoelectron Sheath: The instrument will observe the Moon’s surface environment in radio frequencies, to determine how natural and human-generated activity near the surface interacts with and could interfere with science conducted there. Stereo Cameras for Lunar Plume-Surface Studies: A suite of four tiny cameras to capture imagery showing how the Moon’s surface changes from interactions with the spacecraft’s engine plume during and after descent. Intuitive Machines’ Nova-C-class lunar lander, named Odysseus, is scheduled to land on the Moon’s South Pole region near the lunar feature known as Malapert A on Thursday, Feb. 22. This relatively flat and safe region is within the otherwise heavily cratered southern highlands on the side of the Moon visible from Earth. Landing near Malapert A will also help mission planners understand how to communicate and send data back to Earth from a location where Earth is low on the lunar horizon. The NASA science aboard will spend approximately seven days gathering valuable scientific data about Earth’s nearest neighbor, helping pave the way for the first woman and first person of color to explore the Moon under Artemis. Learn more about NASA’s CLPS initiative at: https://www.nasa.gov/clps -end- Karen Fox / Alise FisherHeadquarters, Washington202-358-1600 / 202-358-2546karen.c.fox@nasa.gov / alise.m.fisher@nasa.gov   Nilufar RamjiJohnson Space Center, Houston281-483-5111nilufar.ramji@nasa.gov Antonia JaramilloKennedy Space Center, Florida321-501-8425antonia.jaramillobotero@nasa.gov Share Details Last Updated Feb 15, 2024 LocationNASA Headquarters Related TermsMissionsArtemisCommercial Lunar Payload Services (CLPS)

[simonh]

Proba-3's laser-precise positioning by European Space Agency Via Flickr: An infrared view of a laser-based test campaign – taking place at Redwire Space in Kruibeke, Belgium – which represents crucial preparation for ESA’s precision formation flying mission, Proba-3. Later this year, two satellites will be launched together into orbit to maintain formation relative to each other down to a few millimetres, creating an artificial solar eclipse in space. Proba-3’s ‘Occulter’ spacecraft will cast a shadow onto the other ‘Coronagraph’ spacecraft to block out the fiery face of the Sun and make the ghostly solar corona available for sustained observation for up to six hours per 19.5 hour orbit. However to maintain the position of a shadow just a few centimetres across on the Coronagraph satellite from the Occulter satellite around 150 m away, the two satellites rely on a suite of sensors, including intersatellite radio links, GNSS, visual imaging and – for the most precise positioning at closest range – a laser metrology (or ‘measurement of measurement’) system. This system will shoot a laser from the Occulter spacecraft toward a corner cube retroreflector placed on the face of the Coronagraph spacecraft for tracking of relative position and attitude (pointing direction), achieving millimetre precision. “To calibrate Proba-3’s laser metrology system, its performance was tested within the 60-m long Redwire cleanroom,” explains Damien Galano, Proba-3’s mission manager. “The Coronagraph’s laser was reflected off a retroreflector and the resulting positioning measurements checked against absolute ‘ground truth’ using a separate laser tracking system.” This mission is being put together for ESA by a consortium led by Spain’s Sener, with participation by more than 29 companies from 14 countries. The Proba-3 platforms have been designed by Airbus Defence and Space in Spain and satellite integration by Redwire in Belgium. GMV in Spain is responsible for Proba-3’s formation flying subsystem while its main coronagraph instrument comes from Belgium’s Centre Spatial de Liège, CSL. Proba-3 is due to be launched by PSLV-XL launcher from India in September. Credits: ESA - M. Pédoussaut

[puffdenlilledragen]

HEY IMPORTANT I have a hole in my english vocab and wikipedia claims the word i want is retroreflector but i sincerely doubt that is what is used in everyday so

what do you call these in english

[bacony-cakes]

apollo retroreflector

look at my head boy

[coeoptics]

Leading Manufacturer & Supplier of Custom Optics and Optical Components

COE Optics is an eminent provider of Corner Cube Retroreflector, right angle prism & optical beam splitter to our clients. These are used to reflect a light beam back to the direction that it comes from.