Category Archives: STEM

Science, Technology, Engineering, and Mathematics

What Can A Raspberry Pi Do In Space?

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The Astro Pi board is a Raspberry Pi HAT and will comprise the following:

  • Gyroscope, accelerometer and magnetometer sensor
  • Temperature sensor
  • Barometric pressure sensor
  • Humidity sensor
  • Real time clock with backup battery
  • 8×8 RGB LED display
  • Several push buttons

It will also be equipped with both camera module and an infra-red camera.

via Astro Pi – What Can A Raspberry Pi Do In Space?.

During his mission Tim Peake will deploy the Astro Pis, upload the winning code whilst in orbit, set them running, collect the data generated and then download it to be distributed to the winning teams.

Kepler’s Three Laws

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Kepler’s three laws of planetary motion can be described as follows:

  • The path of the planets about the sun is elliptical in shape, with the center of the sun being located at one focus. (The Law of Ellipses)
  • An imaginary line drawn from the center of the sun to the center of the planet will sweep out equal areas in equal intervals of time. (The Law of Equal Areas)
  • The ratio of the squares of the periods of any two planets is equal to the ratio of the cubes of their average distances from the sun. (The Law of Harmonies)

via Kepler’s Three Laws.

Pluto-bound spacecraft ends hibernation to start mission

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New Horizons is now so far away that radio signals traveling at the speed of light take four hours and 25 minutes to reach Earth.

The scientific observation of Pluto, its entourage of moons and other bodies in the solar system’s frozen backyard begins Jan. 15, program managers said. The closest approach is expected on July 14.

via Pluto-bound spacecraft ends hibernation to start mission | Reuters.

The Mathematical Trick That Helped Smash The Record For The Largest Number Ever Factorised By A…

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And in any case, because this trick works using only 4 qubits, it can easily be reproduced on any classical computer. So it’s not so useful after all.

via The Mathematical Trick That Helped Smash The Record For The Largest Number Ever Factorised By A… — The Physics arXiv Blog — Medium.

Here’s a paper on this subject:

[1411.6758] Quantum factorization of 56153 with only 4 qubits.

Rosetta to deploy lander on 12 November

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Two robust landing scenarios have been identified, one for the primary site and one for the backup. Both anticipate separation and landing on 12 November.

For the primary landing scenario, targeting Site J, Rosetta will release Philae at 08:35 GMT/09:35 CET at a distance of 22.5 km from the centre of the comet, landing about seven hours later. The one-way signal travel time between Rosetta and Earth on 12 November is 28 minutes 20 seconds, meaning that confirmation of the landing will arrive at Earth ground stations at around 16:00 GMT/17:00 CET.

via Rosetta to deploy lander on 12 November / Rosetta / Space Science / Our Activities / ESA.

What is the difference between procedural programming and functional programming?

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I’ve read the Wikipedia articles for both procedural programming and functional programming, but I’m still slightly confused. Could someone boil it down to the core?

via glossary – What is the difference between procedural programming and functional programming? – Stack Overflow.

A functional language (ideally) allows you to write a mathematical function, i.e. a function that takes n arguments and returns a value. If the program is executed, this function is evaluated.

A procedural language, on the other hand, performs a series of sequential steps, where the functional program would be nested. There’s a way of transforming sequential logic into functional logic called continuation passing style.

As a consequence, a purely functional program always yields the same value for an input, and the order of evaluation is not well-defined; which means that uncertain values like user input or random values are hard to model in purely functional languages.

The Plane Crash That Gave Americans GPS

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The U.S. had already launched into orbit almost a dozen satellites that could help locate its military craft, on land, in the air, or on the sea. But the use of the system was restricted. (It was meant, for instance, to help powerful weapons hit their targets—it wasn’t the sort of tool governments usually want to make publicly available.) Now, Reagan said, as soon as the next iteration of the GPS system was working, it would be available for free.

It took more than $10 billion and until over 10 years for the second version of the U.S.’s GPS system to come fully online. But in 1995, as promised, it was available to private companies for consumer applications. Sort of. The government had built in some protection for itself—”selective availability,” which reserved access to the best, most precise signals for the U.S. military (and anyone it chose to share that power with).

via The Plane Crash That Gave Americans GPS – The Atlantic.

An Introduction to Semiconductor Physics, Technology, and Industry

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The simplest place to start is the materials. Silicon is incredibly important as a material in the industry because it’s a semiconductor. Of course, the name is self-explanatory, but there’s more to it. The key here is the band structure. Band structure refers to the “bands” of energy levels that form due to the sheer number of orbital states that can be occupied in molecules. Those that understand how electron orbitals work will point out that each energy level is discrete, but due to the sheer number of orbital configurations, a seemingly continuous distribution of energy can be seen. However, relatively large gaps still exist; known as a band gap, these are an energy state that an electron cannot occupy.

via AnandTech | An Introduction to Semiconductor Physics, Technology, and Industry – Print View.

And on and on it goes.  This is a great writeup for understanding how integrated circuits work.

The 2014 Nobel Prize in Physics

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This year’s Nobel Laureates are rewarded for having invented a new energy-efficient and environment-friendly light source – the blue light-emitting diode (LED). In the spirit of Alfred Nobel the Prize rewards an invention of greatest benefit to mankind; using blue LEDs, white light can be created in a new way. With the advent of LED lamps we now have more long-lasting and more efficient alternatives to older light sources.

via The 2014 Nobel Prize in Physics – Press Release.

When Isamu Akasaki, Hiroshi Amano and Shuji Nakamura produced bright blue light beams from their semi-conductors in the early 1990s, they triggered a funda-mental transformation of lighting technology. Red and green diodes had been around for a long time but without blue light, white lamps could not be created. Despite considerable efforts, both in the scientific community and in industry, the blue LED had remained a challenge for three decades.