Air-Breathing Rocket Engine Promises Future Space Planes

If you are a certain age, you probably remember the promise of supersonic transports. The Concorde took less than 4 hours to go across the Atlantic, but it stopped flying in 2003 and ended commercial supersonic passenger flights  But back in the 1970s, we thought the Concorde would give way not to older technology, but to newer. After all, man had just walked on the moon and suborbital transports could make the same trip in 30 minutes and — according to Elon Musk — go between any two points on the Earth in an hour or less. A key component to making suborbital flights as common as normal jet travel is a reasonable engine that can carry a plane to the edge of space. That’s where the UK’s Sabre engine comes into play. Part jet and part rocket, the engine uses novel new technology and two different operating modes to power the next generation of spaceplane. The BBC reports that parts of the new engine will undergo a new phase of testing next month.

The company behind the technology, Reaction Engines, Ltd, uses the engine in an air-breathing jet mode until it hits 5.5 times the speed of sound. Then the same engine becomes a rocket and can propel the vehicle at up to 25 times the speed of sound.

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Maybe You Really Can Sense Magnetic Fields

We’ve known for years that many animals can somehow sense magnetic fields. Birds apparently use the Earth’s magnetic field to navigate. Dogs can find a box containing a magnet better than they can find a similar box with a food treat in it. But humans, apparently, can’t visualize magnetic fields without help. Several scientists at California, New Jersey, and Japan have done experiments that seem to show that people’s brains do have changes when a magnetic field rotates. If the paper, titled “Transduction of the Geomagnetic Field as Evidenced from Alpha-band Activity in the Human Brain” is a bit much for you, might enjoy the video from Veritasium, below, which is much easier to parse than the paper.

To see it work, a subject sits in a dark isolated room with an electrode cap that picks up the subject’s EEG. The study shows that different people have different sensitivity to the field. Also, picking up a magnetic field in an isolated chamber is different from picking it up on the sidewalk and using it to navigate with. Continue reading “Maybe You Really Can Sense Magnetic Fields”

Make Your Own Quantum Dots

Quantum dots certainly sound as if they should be something cool, but carry the hazardous baggage of being sometimes made from cadmium which can be dangerous. What are they? In essence, they are nanometer-scale particles, so small that when high energy light hits them, the photons will be absorbed and re-emitted at a lower energy state. You can easily make non-toxic quantum dots in your kitchen. Apart from the cool factor, they can be used as fluorescent dyes, inks, and possibly paints. [StrangelyAmusing] explains how in the video below.

You don’t need much in the way of equipment. A microwave oven, a Pyrex (borosilicate) container, and gloves. You’ll also need plastic pipettes and a blacklight — possibly the most exotic two items on the list. The ingredients are equally mundane: vinegar, baking soda, water, and sugar.

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Library Makes ESP Over the Air Updates Easy

Potentially, one of the great things about having a device connected to the network is that you can update it remotely. However, how do you make that happen? If you use the Arduino setup for the ESP8266 or ESP32, you might try [scottchiefbaker’s] library which promises to make the process easy.

Adding it looks to be simple. You’ll need an include, of course. If you don’t mind using port 8080 and the path /webota, you only need to call handle_webota() from your main loop. If you want to change the defaults, you’ll need to add an extra call in your setup. You also need to set up a few global variables to specify your network parameters.

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Maritime Analog Computer From 1503 Is The Oldest Remaining

We might not think of analog computers as having existed in the 1500s, but in fact the astrolabe first appeared around 220 BC. However, as you might expect only a few very old ones still exist. Early astrolabes were often wooden and were difficult to use aboard ships, however brass astrolabes with special features were more accurate on the deck of a ship underway. A recent archeological find from one of Vasco da Gama’s ships that sunk in the Arabian Sea has brought the number of known archeologically-significant instruments to 104, and also is one of the few nautical versions to employ a solid disk. As of now, it is the oldest known maritime astrolabe found so far — the ship sunk in 1503. You might wonder how the 104th astrolabe became number 108, but the catalog includes a few pieces or fragments of astrolabes. If you count those, there are 108 items in the catalog.

If you think archeology is about men in fedoras carrying whips, or stuffy old men wandering around tombs, you should have a look at the article about this find. In addition to divers recovering the piece from the shipwreck (see the video, below), the science involved in restoring it and analyzing it includes chemistry, lasers, X-rays, and energy-dispersive spectroscopy.

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Venabili is the Delightful Keyboard You Can’t Buy

If you code or write a lot, you live or die with your keyboard. The Venabili web site calls Venabili “the delightful keyboard” which begs the question: what makes a keyboard delightful. The site continues:

“Venabili is a 40% mechanical, programmable, ergonomic and hackable computer keyboard.

Being a fully programmable keyboard, it gives you the ability to create layers of functionality, declare multifunction keys that can operate as both modifiers and normal keys, control the mouse, define macros, and more.”

Sounds at least 40% delightful, right? Where do you buy one? You don’t. The keyboard is a set of plans and like a Jedi lightsaber, you have to build your own. Continue reading “Venabili is the Delightful Keyboard You Can’t Buy”

You’re Listening To Quantum Radio

Researchers at Delft University of Technology have created a detector that enables the detection of a single photon’s worth of radio frequency energy. The chip is only 10 mm square and the team plans to use it to explore the relationship of mass and gravity to quantum theory.

The chip has immediate applications in MRI and radio astronomy. Traditionally, detecting a single photon at radio frequencies is difficult due to the significance of thermal fluctuations. At lower frequencies, cryogenic cooling can reduce the issue, but as frequency increases the fluctuations are harder to tame.

The trick requires a qubit that samples the radio frequency energy. While the radio source is at 173 MHz, the qubit is at 1 GHz, allowing a fine time resolution. Coupling of the two is via an LC circuit that uses a Josephson junction which, of course, requires very cold temperatures. Continue reading “You’re Listening To Quantum Radio”