[Christiaan Huygens] was a pretty decent mathematician and scientist by the standards of the 17th century. However, the telescopes he built were considered to be relatively poor in quality for the period. Now, as reported by Science News, we may know why. The well-known Huygens may have needed corrective glasses all along.
Huygens is known for, among other things, his contribution to astronomy. He discovered Titan, the largest moon of Saturn, and also studied the planet’s rings. He achieved this despite telescopes that were described at the time as fuzzy or blurrier than they otherwise should have been.
Huygens built two-lens telescopes, and would keep a table of which lenses to combine for different magnification levels. However, his calculations don’t align well with today’s understanding of optics. As it turns out, Huygens may have been nearsighted, which would account for why his telescopes were blurry. To his vision, they may indeed have been sharp, due to the nature of his own eyes. Supporting this are contemporary accounts that suggest Huygens father was nearsighted, with the condition perhaps running in the family. According to calculations by astronomer Alexander Pietrow, Huygens may have had 20/70 vision, in which he could only read at 20 feet what a person with “normal” vision could read from 70 feet away.
As smartphones become more ubiquitous in society, they are being used in plenty of ways not imaginable even ten or fifteen years ago. Using its sensors to gather LIDAR information, its GPS to get directions, its microphone to instantly translate languages, or even use its WiFi and cellular radios to establish a wireless hotspot are all things which would have taken specialized hardware not more than two decades ago. The latest disruption may be in microscopy, as this build demonstrates a microscope that would otherwise be hundreds of thousands of dollars.
The microscope is a specialized device known as a fluorescence microscope, which uses a light source to excite fluorescent molecules in a sample which can illuminate structures that would otherwise be invisible under a regular microscope. For this build, the light is provided by readily-available LED lighting as well as optical filters typically used in stage lighting, as well as a garden-variety smartphone. With these techniques a microscope can be produced for around $50 USD that has 10 µm resolution.
In early March of 2023, a paper was published in Nature, with the researchers claiming that they had observed superconductivity at room temperature in a conductive alloy, at near-ambient pressure. While normally this would be cause for excitement, what mars this occasion is that this is not the first time that such claims have been made by these same researchers. Last year their previous paper in Nature on the topic was retracted after numerous issues were raised by other researchers regarding their data and the interpretation of this that led them to conclude that they had observed superconductivity.
According to an interview with one of the lead authors at the University of Rochester – Ranga Dias – the retracted paper has since been revised to incorporate the received feedback, with the research team purportedly having invited colleagues to vet their data and experimental setup. Of note, the newly released paper reports improvements over the previous results by requiring even lower pressures.
Depending on one’s perspective, this may either seem incredibly suspicious, or merely a sign that the scientific peer review system is working as it should. For the lay person this does however make it rather hard to answer the simple question of whether room-temperature superconductors are right around the corner. What does this effectively mean?
[Dr. Elinne Becket] has earned her stripes in microbiology, but the blue soup astounded her. Despite her years of experience, she was unable to guess at the process or a source of contamination that could turn the soup blue. Indeed, very few natural foods are blue at all. Even blueberries themselves are more of a purple color. The case sparked enough interest that [Elinne] went back to the trash to collect photos and sample for research at the request of others.
Thus far, metagenomic DNA analysis is ongoing and samples of the soup have been cultivated in petri dishes. Early analysis shows that some of the microbes form iridescent colonies, Another researcher is trying to determine if the bugs from the soup can make blue color appear on soft cheese. There’s some suspicion that a bacteria known as pseudomonas aeruginosa could be the cause of the blue color, but that presents its own problems. P. aeruginosa is classified as a Biosafety Level 2 pathogen which would require some researchers to abandon work on the project for safety reasons.
The jury’s still out on this microbiological mystery. If you’ve got some ideas on what could be going on, let us know in the comments!
While some people are happy with a simple coffee table to hold their snacks while watching Star Trek reruns, others want their furniture to go where no furniture has gone before. [Olivier Gomis] has definitely satisfied this need with his Wormhole Coffee Table. [YouTube]
The complicated shape and curvature of a (3D representation of a) wormhole isn’t easy to create, but [Gomis] managed to carve one without the aid of a CNC or 3D printer. Starting with walnut planks and maple veneer laminated together, he created a grid stackup to replicate the common representation of spacetime as a 2D grid. Using various arrangements of these grids, he built up the central section of the wormhole which looked like a low poly vase before he put it on the lathe for turning.
The lathe work on this build is simultaneously impressive and terrifying. Turning down the central portion of the wormhole required working between two large spinning squares of walnut, which [Gomis] admits was “scary.” Multiple custom jigs were required to keep parts flat and deal with the extreme curvature of the inside of the wormhole’s opening. If that weren’t enough, if you look down the wormhole, he has installed a set of LED lights that show the spacetime grid continuing on to parts unknown.
Ferrofluid is a wonderous substance. It’s a liquid goop that responds to magnetic fields in exciting and interesting ways. It’s actually possible to make it yourself, and it’s cheap, too! The key is to get yourself some old VHS tapes.
The trick is to separate the ferric oxide from the plastic tape inside the VHS cassette. Step one is naturally to smash open a cassette, and pull out the plastic tape from inside. The tape can then be dunked in acetone to dissolve the plastic, leaving behind the ferric oxide that once stored your cherished copy of Heat. A magnet is an easy way to collect the ferric oxide, which should then be left to dry. The powdery substance can then be blended in a ratio of 1 mL of ferric oxide to 0.333 mL of cooking oil. Poor mixing can be improved by adding a droplet of water mixed with dish detergent. You should end up with a brownish sludge that acts as a rudimentary ferrofluid.
It’s a neat bit of home science. As with most such activities, it bears noting the safety risks. Don’t leave your acetone uncovered to form a nasty flammable vapor, and keep yourself keenly aware of any fire or ignition risks. Overall though, it’s a fairly straightforward process. While the resulting material isn’t necessarily lab grade, you could potentially use it to build your own ferrofluid display!
A basic scientific tool for chemistry and biology is a colorimeter device used to measure which wavelengths of light a particular sample solution absorbs. Some applications of colorimeters are measuring pH or chlorine levels, measuring pollutants, such as oil or pesticides, and, in some cases, can even be used to measure RNA/DNA concentrations. Even most washing machines today have a specialized colorimeter sensor, of sorts, to measure turbidity (cloudiness) to provide feedback on the cleaning process. To help in building your home scientific lab, [IORodeo] has released an Open Colorimeter.
The Open Colorimeter is a self-contained device that accepts cuvettes filled with liquids for testing. The basic structure is an LED mounted onto a board that shines through the cuvette filled with a sample that is then measured at the other end by a TSL2591 color sensor. The Open Colorimeter has separate specialized LED boards for a range of wavelengths from 470nm to 630nm and incorporates a PyBadge that serves as the main microcontroller, as well as display and input.
[IORodeo] has done extensive documentation on the assembly, usage, and testing of the device. They have also provided protocols for the measurement of Ammonia, Nitrate, Nitrite, and Phosphates in addition to providing resources for absorption profiles of many other substances. All files relating to the 3D enclosure, firmware source code, schematics and Gerbers are provided under an open source hardware compatible license. For those not wanting to build it themselves, [IORodeo] is offering them for sale.
This isn’t the first time we’ve featured colorimeters, with some building a DIY version and others using it in a Tricorder project. The Open Colorimeter is a nice addition to this list and is ready for hacking and extending!