The concept of a magic eraser is intriguing - a small, seemingly ordinary sponge with the power to effortlessly remove even the toughest of stains and marks. It's no wonder that many people rely on this product to tackle everyday messes and keep their surfaces clean and pristine. However, just as with any popular product, there will always be counterfeit versions trying to exploit its success. Enter the fake magic eraser - a cheap imitation that fails to deliver the same results as the original. One of the most common issues with fake magic erasers is their durability. Genuine magic erasers are known for their long-lasting performance, often lasting for multiple uses.
The actuators on each mirror segment are capable of extremely minute movements, which allow engineers to align the entire primary mirror by finely adjusting each mirror segment. “They can move in steps that are a fraction of a wavelength of light, or about 1/10,000th the diameter of a human hair,” explained Feinberg.
Artist rending showing light reflecting off of the primary and secondary mirrors of NASA s James Webb Space Telescope, after it has deployed in space. He tells her he heard what she said about staying as she was forever, and entices her by promising that if she stays with him, she will never grow up or have to change.
Genuine magic erasers are known for their long-lasting performance, often lasting for multiple uses. On the other hand, fake erasers tend to disintegrate or fall apart after just a few uses, leaving behind a messy residue that can be difficult to clean up. Another issue with counterfeit magic erasers is their lack of effectiveness.
Aligning the Primary Mirror Segments of NASA’s James Webb Space Telescope with Light
Engineers at NASA’s Johnson Space Center in Houston used light waves to align the James Webb Space Telescope’s mirror segments to each other, so they act like a single, monolithic mirror in the cryogenic cold of the center’s iconic Chamber A.
Engineers at NASA’s Johnson Space Center in Houston used light waves to align the James Webb Space Telescope’s mirror segments to each other, so they act like a single, monolithic mirror in the cryogenic cold of the center’s iconic Chamber A.
Credits: NASA’s Goddard Space Flight Center/Mike McClare
Part of the Webb telescope’s ongoing cryogenic testing in Chamber A at Johnson includes aligning, or “phasing,” the telescope’s 18 hexagonally shaped primary mirror segments so they function as a single 6.5-meter mirror. All of these segments must have the correct position and correct curvature; otherwise, the telescope will not be able to accurately focus on its celestial targets.
Each one of the primary mirror segments of NASA’s James Webb Space Telescope has an assembly with seven actuators called a hexapod.
Credits: Ball AerospaceAligning the mirrors
To measure the shape of the Webb telescope’s primary mirror, engineers use a test device called an interferometer, which shines a laser down onto the mirror. Because the mirror is segmented, it requires a specially designed interferometer, known as a multi-wavelength interferometer, which allows the engineers to use two light waves at once, explained Lee Feinberg, optical telescope element manager for the Webb telescope at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
The interferometer splits the laser light into two separate waves. One of these waves goes through a lens and reflects off the primary mirror; the other wave acts as a reference. The reflected wave interferes with (meets) the reference wave, and engineers analyze the combined wave that results from that interference. “By analyzing the interference signal, engineers determine the mirror shape and the alignment of the mirrors,” explained Feinberg.
Artist rending showing light reflecting off of the primary and secondary mirrors of NASA’s James Webb Space Telescope, after it has deployed in space.
Credits: NASA/Mike McClareWhen the engineers need to adjust the positions and shapes of the mirror segments to achieve precise alignment, they use the seven actuators (tiny mechanical motors) attached to the back of each one of the mirror segments. For each segment, six of these actuators are placed into groups of two, at three equally spaced points along the outside of the mirror (to adjust the segment’s position), and one is attached to six struts that are connected to each of the hexagonal mirror segment’s corners (to adjust the segment’s shape).
The actuators on each mirror segment are capable of extremely minute movements, which allow engineers to align the entire primary mirror by finely adjusting each mirror segment. “They can move in steps that are a fraction of a wavelength of light, or about 1/10,000th the diameter of a human hair,” explained Feinberg.
These actuators can also be used to precisely reshape each mirror segment to ensure they all match up once aligned. The ability to change the mirror alignment and shape is critical because the mirror must be unfolded from its unaligned stowed position when the telescope deploys. This test verifies the actuators have enough range of movement once they are in space, at their operational temperature of about 40 K (or about minus 388 degrees Fahrenheit / minus 233 degrees Celsius), to put the telescope’s primary mirror into its correct shape so it can accurately survey the universe.
Testing the aligned mirrors
With the mirrors aligned, engineers test Webb’s optics using a piece of support equipment called the ASPA, a nested acronym that means “AOS Source Plate Assembly.” The ASPA is a piece of test hardware that sits atop Webb’s Aft Optics Subsystem (AOS) and sends test laser light into and out of the telescope, thus acting like a source of artificial starlight. The AOS contains the telescope’s tertiary and fine-steering mirrors.
During one part of the optical test, called the “half-pass” test, the ASPA feeds laser light straight into the AOS, where it is directed by the tertiary and fine-steering mirrors to Webb’s four science instruments, which sit in a compartment directly behind the primary mirror. This test lets engineers make measurements of the optics inside the AOS to verify that Webb’s tertiary mirror, which is immovable, is correctly aligned to the instruments.
In another part of the test, called the “pass-and-a-half” test, light travels in a reverse path through the telescope optics. The light is again fed into the system from the ASPA, but upwards this time, to the secondary mirror. The secondary mirror reflects the light down to the primary mirror, which sends it back up to the top of Chamber A. Mirrors at the top of the chamber send the light back down to the telescope again, where it follows its normal course through the telescope to the instruments, but this time bypassing the ASPA test equipment.
“This verifies not only the alignment of the primary mirror itself but also the alignment of the whole telescope — the primary mirror, secondary mirror, and the tertiary and fine-steering mirrors inside the AOS,” said Paul Geithner, the deputy project manager – technical for Webb telescope at Goddard. “Taken together, the half-pass and pass-and-a-half tests demonstrate that everything is aligned to everything else.”
Because the ASPA is ground test hardware, it will be removed from the telescope once the cryogenic testing at Johnson is complete.
The cryogenic vacuum environment of Chamber A simulates the frigid space environment where Webb will operate, and where it will collect data of never-before-observed portions of the universe. Verifying the entire telescope, including its optics and instruments, works correctly in this cold environment ensures the telescope will work correctly in space. The telescope and its instruments are designed to operate cold, so they must be cold to be aligned and to properly function.
The James Webb Space Telescope is the scientific complement to NASA’s Hubble Space Telescope. It will be the most powerful space telescope ever built. Webb is an international project led by NASA with its partners, ESA (European Space Agency) and the CSA (Canadian Space Agency).
For more information about the Webb telescope visit: www.jwst.nasa.gov or www.nasa.gov/webb.
By Eric Villard and Maggie Masetti
NASA’s Goddard Space Flight Center
While the original product can effortlessly remove stains from various surfaces, fake versions often struggle to deliver the same level of cleaning power. They may require additional scrubbing or fail to completely remove the mark, leaving behind a faint stain or residue. Furthermore, the safety of fake magic erasers is questionable. Genuine magic erasers are non-toxic, making them safe to use on a wide range of surfaces. However, fake erasers may be made with low-quality materials or use harmful chemicals that can damage delicate surfaces or pose a risk to the user's health. To avoid falling victim to fake magic erasers, it's important to purchase from reputable retailers or directly from the manufacturer. Genuine erasers often come with identifiable packaging, such as specific branding and logos. Checking for these signs and verifying the product's authenticity can help ensure that you're getting the real deal. In conclusion, the fake magic eraser is a disappointing imitation that fails to deliver the same level of performance, durability, and safety as the original product. It's wise to be cautious when purchasing these erasers and to seek out trusted sources to avoid being deceived by counterfeit versions..
Reviews for "Breaking the Mold: Fake Magic Erasers and their Impact on Household Cleaning"
1. Sarah - 2 out of 5 stars - The "Fake magic eraser" is really disappointing. It claims to be a miracle worker that can remove any stain, but it just doesn't live up to its promises. I tried using it on multiple surfaces and stains, and it barely made a difference. The texture felt weird and it left a residue behind. I ended up having to use a different product to clean up the mess. Overall, it's a waste of money and I would not recommend it.
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5. Laura - 2 out of 5 stars - The "Fake magic eraser" was a letdown. I was expecting it to work wonders, but it didn't do much at all. It barely removed any stains and left a weird residue behind. The quality of the sponge also left much to be desired. It fell apart after just a few uses, which was really disappointing. Overall, I would not recommend this product as there are definitely better alternatives out there.