Test Equipment, Shim Washers, And A 30 Year Old Space Telescope

April 29, 2020 by Al Williams 38 Comments

This year marks the 30th anniversary of the Hubble Space Telescope. When you see all the great pictures today, it is hard to remember that when it first launched, it was nearly a failure, taking fuzzy pictures. The story of how that problem was fixed while the telescope was whizzing through space is a good one. But there’s another story: how did a $1.5 billion satellite get launched with defective optics? After all, we know space hardware gets tested and retested and, typically, little expense is spared to make sure once a satellite is in orbit, it will work well for a long time.

The problem was with a mirror. You might think mirrors are pretty simple, but it turns out there’s a lot to know about mirrors. For astronomy, you need a first surface mirror which is different from your bathroom mirror which almost certainly reflects off the back of the glass. In addition, the mirrors need a very precise curve to focus light.

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Washing Your Hands With 20,000 Volts

April 28, 2020 by Tom Nardi 33 Comments

These last few weeks we’ve all been reminded about the importance of washing our hands. It’s not complicated: you just need soap, water, and about 30 seconds worth of effort. In a pinch you can even use an alcohol-based hand sanitizer. But what if there was an even better way of killing bacteria and germs on our hands? One that’s easy, fast, and doesn’t even require you to touch anything. There might be, if you’ve got a high voltage generator laying around.

In his latest video, [Jay Bowles] proposes a novel concept: using the ozone generated by high-voltage corona discharge for rapid and complete hand sterilization. He explains that there’s plenty of research demonstrating the effectiveness of ozone gas a decontamination agent, and since it’s produced in abundance by coronal discharge, the high-voltage generators of the sort he experiments with could double as visually striking hand sanitizers.

Looking to test this theory, [Jay] sets up an experiment using agar plates. He inoculates half of the plates with swabs that he rubbed on his unwashed hands, and then repeats the process after passing his hands over the high-voltage generator for about 15 seconds. The plates were then stored at a relatively constant 23°C (75°F), thanks to the use of his microwave as a makeshift incubator. After 48 hours, the difference between the two sets of plates is pretty striking.

Despite what appears to be the nearly complete eradication of bacteria on his hands after exposing them to the ozone generator, [Jay] is quick to point out that he’s not trying to give out any medical advice with this video. This simple experiment doesn’t cover all forms of bacteria, and he doesn’t have the facilities to test the method against viruses. The safest thing you can do right now is follow the guidelines from agencies like the CDC and just wash your hands the old fashioned way; but the concept outlined here certainly looks worthy of further discussion and experimentation.

Regular viewers of his channel may notice that the device in this video as actually a modified version of the hardware he used to experiment with electrophotography last year.

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Freeze Laser Beams — Sort Of

April 23, 2020 by Al Williams 5 Comments

They say a picture is worth a thousand words, and by that logic a video must be worth millions. However, from nearly the dawn of photography around 1840, photographers have made fake photographs. In modern times, Photoshop and Deepfake make you mistrust images and videos. [Action Lab] has a great camera trick in which it looks like he can control the speed of light. You can see the video below.

You probably can guess that he can’t really do it. But he has videos where a real laser beam appears to slowly move across the screen like a laser blaster shot in a movie. You might think you only need to slow down the video speed, but light is really fast, so you probably can’t practically pull that stunt.

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Limiting Factor Submersible Is In A League Of Its Own

April 22, 2020 by Kristina Panos 26 Comments

Space may be the final frontier, but there are still Earthly frontiers that a select few have visited — the deepest depths of the high seas. Victor Vescovo, a Texas businessman and former Naval officer, is one of those few. Last spring, Vescovo realized his dream of becoming the first person to scrape the bottoms of all five oceans.

Vescovo descended alone in Limiting Factor, a $37 million two-seater submersible he commissioned from Triton, a private manufacturer who made this feat of engineering come to life. Vescovo and the crew discovered over 40 new species of aquatic lifeforms throughout the course of their Five Deeps expedition. But the attention-getting takeaway came when Vescovo visited the absolute lowest point on Earth. In the Challenger Deep portion of the Marianas Trench, seven miles below sea level, he saw a plastic bag drift by in the abyss.

One normal-sounding quirk sets this sub apart from others: it’s made to be reusable. You read that right, most super-deep divers never manage to dive over and over again.

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Searching For Alien Life With The Sun As Gravitational Telescope

April 21, 2020 by Moritz v. Sivers 19 Comments

Astronomy is undoubtedly one of the most exciting subjects in physics. Especially the search for exoplanets has been a thriving field in the last decades. While the first exoplanet was only discovered in 1992, there are now 4,144 confirmed exoplanets (as of 2nd April 2020). Naturally, we Sci-Fi lovers are most interested in the 55 potentially habitable exoplanets. Unfortunately, taking an image of an Earth 2.0 with enough detail to identify potential features of life is impossible with conventional telescopes.

The solar gravitational lens mission, which has recently been selected for phase III funding by the NASA Innovative Advanced Concepts (NIAC) program, is aiming to change that by taking advantage of the Sun’s gravitational lensing effect. Continue reading “Searching For Alien Life With The Sun As Gravitational Telescope” →

How Can Heavy Metal Fly?

April 17, 2020 by Jenny List 18 Comments

Scientists found a surprising amount of lead in a glacier. They were studying atmospheric pollution by sampling ice cores taken from Alpine glaciers. The surprising part is that they found more lead in strata from the late 13th century than they had in those deposited at the height of the Industrial Revolution. Surely mediaeval times were supposed to be more about knights in shining armour than dark satanic mills, what on earth was going on? Why was the lead industry in overdrive in an age when a wooden water wheel represented high technology?

The answer lies in the lead smelting methods used a thousand miles away from that glacier, and in the martyrdom of a mediaeval saint.

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This Camera Captures Piezo Inkjet Micro-Drops For DIY Microfluidics

April 15, 2020 by Donald Papp 6 Comments

In microfluidics, there are “drop on demand” instruments to precisely deposit extremely small volumes (pico- or nano-liters) of fluid. These devices are prohibitively expensive, so [Kyle] set out to design a system using hobbyist-level parts for under $1000. As part of this, he has a fascinating use case for a specialized camera: capturing the formation and shape of a micro-drop as it is made.

There are so many different parts to this effort that it’s all worth a read, but the two big design elements come down to:

Making the microdrop using a piezo element
Ensuring the drop is made correctly, and visually troubleshooting

Working prototype. The piezo tube is inside the blue piece at the top. The camera is to the right, and the LED strobe is on the left.

It’s one thing to make an inkjet element in a printer work, but it’s quite another to make a piezoelectric element dispense arbitrary liquids in a controlled, repeatable, and predictable way. Because piezoelectric elements force liquid out with a mechanical motion, different liquids require different drive signals and that kind of experimentation requires a way to see what is going on, hence the need for a drop observation camera.

[Kyle] ended up taking the lens assembly from a cheap USB microscope and mating it to his Korukesu C1 USB Camera with a 3D printed assembly. Another 3D printed enclosure doubles as a lightbox, holding the piezo tube in the center with the LED strobe and camera on opposite sides. The whole assembly had a few false starts, but in the end [Kyle] seems pretty happy with his results. The device is briefly described at a high level here. There are some rough edges, but it’s a working system.

Inkjet technology has been around for a long time (you can see a thirty-plus year old inkjet printer in action here) but it’s worth mentioning that not all inkjet heads are alike. Most inkjet printer heads operate thermally, which means a flash of heat vaporizes some ink to expel a micro-drop. These heads aren’t very suitable for microfluidics because not only do they rely on vaporizing the liquid, but they also don’t work well with anything other than the ink they’re designed for. Piezoelectric print heads are less common, but are more suited to the kind of work [Kyle] is doing.