These Giant Mesh Nets Provide Drinking Water In The Driest Desert On Earth.

Smooth Ride, Bumpy Road

Why are wheels circular? Why aren’t they triangular or square shaped?

That is a question that you might have pondered at some point in your life ( perhaps as a shower-thought? ) But sometimes even the most simple questions have the most elegant answers!

A square wheel can roll smoothly if the ground consists of evenly shaped inverted catenaries of the right size and curvature.

What is a Catenary?

Well, it is the curve that a hanging cable assumes under its own weight when supported only at its ends. You find these everywhere!

Those chains on the pavement,

those hanging cables on a power transmission station,

or maybe a chandelier is of your type

All are catenaries!

Although it superficially resembles a parabola, it is NOT!

Practicality

The mythbusters (like always) decided to give the four wheel vehicle a try.

And found out that, get this - with speed, a truck fitted with square wheels can deliver a relatively smooth ride, despite that bouncy start!

Well, although circular wheels still remain as the king of wheels, it is nice to know that we do have some alternatives up our sleeve!

Merry Christmas :)

PC: Etan J. Tal, kamel15

What is glass?

When most people think of glass, their mind probably jumps straight to windows. And perhaps they’ve heard that old myth - that glass is actually a liquid, not a solid.

So what is glass?

Well, you’ve probably seen something like this before:

The three common phases of matter - gas, liquid, and solid. But you’ll notice that the solid picture is labeled crystalline state. Most people consider glass to be a solid, but it doesn’t quite look like that.

Crystals have a well defined structure, exhibiting long-range order. Glass is what’s called an amorphous material, exhibiting only short-range order. 

Basically, glass is a different kind of solid:

The quartz shown above is an example of a crystalline material. The molecules of glass on the other hand are disordered - yet still solid. 

To create glass, the liquid melt has to be cooled fast enough to prevent the substance from crystallizing. This fast cooling locks the atoms or molecules in the disordered state that looks like the liquid phase. 

Characterizing a substance as a glass also means that this glass transition is reversible. 

While most glass is optically transparent, the properties depend on the composition of the glass. Most of what you see every day is soda-lime-silicate glass, but there are many different kinds of glasses, including sodium borosilicate glass (Pyrex), lead-oxide glass, and aluminosilicate glass.

Sources: x x

Why most metals are silver (but copper and gold aren’t)

If we want to understand what gives a metal its color we first need to understand a little bit about the definition of a metal. Metals are materials that experience metallic bonding - wherein the atoms are so close that there is a veritable “sea of electrons” in the substance. (This is also what makes metals conductors, but that’s another story). Basically each atom donates an electron or two that is free to flow throughout the material, unattached to any particular nucleus. 

This proximity leads to an overlap in the allowed energy levels of electrons (shown in the lower left hand image above); basically the higher empty electronic levels are so close to the uppermost filled levels (also called the Fermi level) that they form an essentially continuous band of allowed energies. 

Now, backtracking a little bit, color in a substance is caused when a material doesn’t absorb a particular wavelength of light. Because of the empty energy levels mentioned above, metals generally can absorb all wavelengths of light in the visible spectrum. This implies that a metal should look black, except that the excited electron can immediately fall back to the state that it came from, emitting exactly the same energy, causing a flat piece of metal to appear reflective. Thus, the reason why most metals are silver. (Also, the flatter a metal, the more reflective, thanks to diffuse vs. specular reflection).

For a few select metals, like copper and gold, the absorption and emission of photons are noticeably dependent on wavelength across the visible part of the spectrum. The graph in the lower right image above shows the reflectance of aluminum, silver, and gold, including wavelengths in the infrared and ultraviolet. Aluminum is pretty reflective overall, and silver is highly reflective in the visible region (about 400 to 700 nm), but gold clearly absorbs wavelengths about 500 nm or below. Thus, it most strongly reflects yellow, giving it its characteristic appearance. 

Sources: (first image), 2 (second image), 3 (third image), 4

10 “Spinoffs of Tomorrow” You Can License for Your Business

The job of the our Technology Transfer Program is pretty straight-forward – bring NASA technology down to Earth. But, what does that actually mean? We’re glad you asked! We transfer the cool inventions NASA scientists develop for missions and license them to American businesses and entrepreneurs. And that is where the magic happens: those business-savvy licensees then create goods and products using our NASA tech. Once it hits the market, it becomes a “NASA Spinoff.”

If you’re imagining that sounds like a nightmare of paperwork and bureaucracy, think again. Our new automated “ATLAS” system helps you license your tech in no time — online and without any confusing forms or jargon.

So, sit back and browse this list of NASA tech ripe for the picking (well, licensing.) When you find something you like, follow the links below to apply for a license today! You can also browse the rest of our patent portfolio - full of hundreds of available technologies – by visiting technology.nasa.gov.

1. Soil Remediation with Plant-Fungal Combinations

Ahh, fungus. It’s fun to say and fun to eat—if you are a mushroom fan. But, did you know it can play a crucial role in helping trees grow in contaminated soil? Scientists at our Ames Research Center discovered that a special type of the fungus among us called “Ectomycorrhizal” (or EM for short) can help enhance the growth of trees in areas that have been damaged, such as those from oil spills.

2. Preliminary Research Aerodynamic Design to Lower Drag

When it comes to aircraft, drag can be, well…a drag. Luckily, innovators at our Armstrong Flight Research Center are experimenting with a new wing design that removes adverse yaw (or unwanted twisting) and dramatically increases aircraft efficiency by reducing drag. Known as the “Preliminary Research Aerodynamic Design to Lower Drag (PRANDTL-D)” wing, this design addresses integrated bending moments and lift to achieve drag reduction.

3. Advancements in Nanomaterials

What do aircraft, batteries, and furniture have in common? They can ALL be improved with our nanomaterials.  Nanomaterials are very tiny materials that often have unique optical, electrical and mechanical properties. Innovators at NASA’s Glenn Research Center have developed a suite of materials and methods to optimize the performance of nanomaterials by making them tougher and easier to process. This useful stuff can also help electronics, fuel cells and textiles.

4. Green Precision Cleaning

Industrial cleaning is hard work. It can also be expensive when you have to bring in chemicals to get things squeaky. Enter “Green Precision Cleaning,” which uses the nitrogen bubbles in water instead. The bubbles act as a scrubbing agent to clean equipment. Goddard Space Flight Center scientists developed this system for cleaning tubing and piping that significantly reduces cost and carbon consumption. Deionized water (or water that has been treated to remove most of its mineral ions) takes the place of costlier isopropyl alcohol (IPA) and also leaves no waste, which cuts out the pricey process of disposal. The cleaning system quickly and precisely removes all foreign matter from tubing and piping.

5. Self-Contained Device to Isolate Biological Samples

When it comes to working in space, smaller is always better. Innovators at our Johnson Space Center have developed a self-contained device for isolating microscopic materials like DNA, RNA, proteins, and cells without using pipettes or centrifuges. Think of this technology like a small briefcase full of what you need to isolate genetic material from organisms and microorganisms for analysis away from the lab. The device is also leak-proof, so users are protected from chemical hazards—which is good news for astronauts and Earth-bound scientists alike.

6. Portable, Rapid, Quiet Drill

When it comes to “bringing the boom,” NASA does it better than anyone. But sometimes, we know it’s better to keep the decibels low. That’s why innovators at NASA’s Jet Propulsion Laboratory have developed a new handheld drilling device, suitable for a variety of operations, that is portable, rapid and quiet. Noise from drilling operations often becomes problematic because of the location or time of operations. Nighttime drilling can be particularly bothersome and the use of hearing protection in the high-noise areas may be difficult in some instances due to space restrictions or local hazards. This drill also weighs less than five pounds – talk about portable power.  

7. Damage Detection System for Flat Surfaces

The ability to detect damage to surfaces can be crucial, especially on a sealed environment that sustains human life or critical equipment. Enter Kennedy Space Center’s damage detection system for flat composite surfaces. The system is made up of layered composite material, with some of those layers containing the detection system imbedded right in. Besides one day potentially keeping humans safe on Mars, this tech can also be used on aircrafts, military shelters, inflatable structures and more.

8. Sucrose-Treated Carbon Nanotube and Graphene Yarns and Sheets

We all know what a spoonful of sugar is capable of. But, who knew it could help make some materials stronger? Innovators at NASA’s Langley Research Center did! They use dehydrated sucrose to create yarns and woven sheets of carbon nanotubes and graphene.

The resulting materials are lightweight and strong. Sucrose is inexpensive and readily available, making the process cost-effective. Makes you look at the sweet substance a little differently, doesn’t it?

9. Ultrasonic Stir Welding

NASA scientists needed to find a way to friction weld that would be gentler on their welding equipment. Meet our next tech, ultrasonic stir welding.

NASA’s Marshall Space Flight Center engineers developed ultrasonic stir welding to join large pieces of very high-strength, high-melting-temperature metals such as titanium and Inconel. The addition of ultrasonic energy reduces damaging forces to the stir rod (or the piece of the unit that vibrates so fast, it joins the welding material together), extending its life. The technology also leaves behind a smoother, higher-quality weld.

10. A Field Deployable PiezoElectric Gravimeter (PEG)

It’s important to know that the fuel pumping into rockets has remained fully liquid or if a harmful chemical is leaking out of its container. But each of those things, and the many other places sensors are routinely used, tends to require a specially designed, one-use device.

That can result in time-consuming and costly cycles of design, test and build, since there is no real standardized sensor that can be adapted and used more widely.

To meet this need, the PiezoElectric Gravimeter (PEG) was developed to provide a sensing system and method that can serve as the foundation for a wide variety of sensing applications.

See anything your business could use? Did anything inspire you to start your own company? If so, head to our website at technology.nasa.gov to check them out.

When you’ve found what you need, click, “Apply Now!” Our licensing system, ATLAS, will guide you through the rest.

If the items on this round-up didn’t grab you, that’s ok, too. We have hundreds of other technologies available and ready to license on our website.

And if you want to learn more about the technologies already being used all around you, visit spinoff.nasa.gov.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

Major types of Engines

Straight In-line

This is the type of engine that you find in your quotidian car. Nothing fancy, just all pistons arranged parallel along the vertical direction.

V in-line

Now, this is the sort of the engine that you find on sports cars like the Ferrari. When you hear sports enthusiasts go ‘ Whoa, that’s a V-12! ‘ - it just means that the engine has a V-type arrangement with 12 cylinders.

V +  Inline = V-inline

Commonly referred to as the VR engine.

The name VR6 comes from a combination of V engine (German: V-Motor), and the German word “Reihenmotor” (meaning “inline engine” or “straight engine”)

Volkswagen’s VR6 engines, and the later VR5 variants, are a family of internal combustion engines, characterized by a narrow-angle (10.5° or 15°) V engine configuration.

                    a: straight engine, b: V engine, c: VR engine

W engine

A W engine is a type of reciprocating engine ( again created by Volkswagen) arranged with its cylinders in a configuration in which the cylinder banks resemble the letter W, in the same way those of a V engine resemble the letter V.

Bugatti Veyron’s W16 engine

A W16 engine is used on the Bugatti Veyron. That’s 16 cylinders!

Flat Engine

Flat engines offer several advantages for motorcycles, namely: a low centre of gravity, smoothness, suitability for shaft drive, and (if air-cooled) excellent cooling of the cylinders. You can find them on aircrafts as well

Radial Engine (aka the dancing starfish)

They were used mostly in small aircraft for the propeller

The big advantage of radials was their large frontal area, which meant they could be air cooled, meaning less maintenance, failures, and of course a lower cost of initial purchase and maintenance.

Wankel Engine

This engine has only 3 moving parts and can make a lot of power.However, they are pretty inefficient, the last car to use this was a Mazda RX-8.

Axial Engine

The axial engine is a very interesting design. But they are not widely used because they are just hard to make and running these things at high RPM’s  is a challenge.

Duke engines are equipped with this type.

Jet engine

Commonly jet engines refer to the engines that are found on, well Jets!

Suck,squeeze,bang and blow

Air is sucked in through the front and  squeezed. A controlled explosion follows and the exhaust is blown out through the back

But, Jet engines also include the engines that are found on rockets, hybrids and water-jets. And their mode of operation is different than the one mentioned above.

Pretty cool eh?

Have a great day!

PC: Howstuffworks, Duke, MichaelFrey, Azure.km

** There is also the Stirling Engine. It’s amazing and a topic for an another post. But if you are interested do check out more about it here.

EDIT :  Had forgotten about the VR and the W-engines. My bad! Thanks for pointing it out.:D.

EDIT2: The suck squeeze bang and blow illustration was incorrect. Ergo, changed that.

Google’s Wireless ‘Pixel Buds’ Headphones Can Translate 40 Languages in Real Time

More Than You Ever Wanted to Know About Mechanical Engineering, Part 33: Stress Concentrations With Fluctuating Stresses

There’s one last complication to consider with fluctuating stresses. When we looked at the case of fully reversed stresses (that is, σ_m = 0, σ_a ≠ 0) we found a fatigue stress concentration factor based on the stress concentration factor for a static situation.

With a fluctuating stress, the situation is a little different. Since the mean stress is non-zero, the part is always under some kind of load. We can consider the effects of this constant mean stress separately from the effects of the momentary alternating stress and assign them a separate fatigue stress concentration factor, which we’ll call K_fm.

Let’s think about what’s actually physically happening to a part being subjected to a fluctuating stress. Let’s say we’re dealing with a plate with a slot in it subjected to fluctuating tension.

There’s obviously a large stress concentration at the slot that we’ll have to take into account.

There’s three different scenarios which can occur here. The first is that the maximum stress the plate sees (the largest value of combined mean and alternating stress, taking stress concentrations into account) never approaches the yield strength of the material. The plate just stretches and contracts elastically. This isn’t really any different from our previous situation with fatigue stress concentration factors - we can use the K_f factor we got earlier here.

But suppose the yield strength is exceeded. What happens then? If the maximum stress is greater than the yield strength, then the plate must deform plastically at that point of maximum stress - the slot must widen. If the slot is wider, then the stress concentration is relieved - there’s more room for movement before the geometry stops you. If other words, the fatigue stress concentration factor is lessened.

If it’s just your maximum stress that exceeds the yield strength but your minimum stress is still below it, this localized yielding will be one-sided - you’ll get a slot that’s widened on one side, but you’ll still have some overall mean stress. If this is the case, you base your stress concentration factor on the relationship of the mean and alternating stresses to the yield strength.

If both your minimum and maximum stresses exceed the yield strength of the material, you get a situation where you’ve widened the slot as far as you can without actually breaking the part on both sides and you’re experiencing a stress of magnitude equal to the yield strength at either extreme of the fluctuation. Since you now have a fluctuation with equal and opposite extremes, your mean stress is zero - the mean fatigue stress concentration factor is zero. The scenario is now one of fully reversed loading and the mean stress drops right out of it.

This room starts charging your phone as soon as you walk in. Inspired by Tesla’s vision of global wireless power, scientists at Disney Research company explored how wireless charging works in large spaces. The copper pole at the room’s center sends currents through the walls and floor that charge phones and laptops without harming humans. Source Source 2

Devices can be charged regardless of their orientation in the room thanks to a new receiver design

The setup outside the room

The setup inside the room

18 Science Facts We Didn't Know at The Start of 2017

We've learned so much already.

1. Lungs don’t just facilitate respiration - they also make blood. Mammalian lungs produce more than 10 million platelets (tiny blood cells) per hour, which equates to the majority of platelets circulating the body.

2. It is mathematically possible to build an actual time machine - what’s holding us back is finding materials that can physically bend the fabric of space-time.

3. Siberia has a colossal crater called the ‘doorway to the underworld’, and its permafrost is melting so fast, ancient forests are being exposed for the first time in 200,000 years.

4. The world’s first semi-synthetic organisms are living among us - scientists have given rise to new lifeforms using an expanded, six-letter genetic code.

5. Vantablack - the blackest material known to science - now comes in a handy ‘spray-on’ form and it’s the weirdest thing we’ve seen so far this year.

6. It’s official: time crystals are a new state of matter, and we now have an actual blueprint to create these “impossible” objects at will.

7. A brand new human organ has been classified, and it’s been hiding in plain sight this whole time. Everyone, meet your mesentery.

8. Carl Sagan was freakishly good at predicting the future - his disturbingly accurate description of a world where pseudoscience and scientific illiteracy reigns gave us all moment for pause.

9. A single giant neuron that wraps around the entire circumference of a mouse’s brain has been identified, and it appears to be linked to mammalian consciousness.

10. The world’s rarest and most ancient dog isn’t extinct after all - in fact, the outrageously handsome New Guinea highland wild dog appears to be thriving.

11. Your appendix might not be the useless evolutionary byproduct after all. Unlike your wisdom teeth, your appendix might actually be serving an important biological function - and one that our species isn’t ready to give up just yet.

12. After 130 years, we might have to completely redraw the dinosaur family tree, thanks to a previously unimportant cat-sized fossil from Scotland.

13. Polycystic ovary syndrome might actually start in the brain, not the ovaries.

14. Earth appears to have a whole new continent called Zealandia, which would wreak havoc on all those textbooks and atlases we’ve got lying around.

15. Humans have had a bigger impact on Earth’s geology than the infamous Great Oxidation Event 2.3 billion years ago, and now scientists are calling for a new geological epoch - the Anthropocene - to be officially recognised.

16. Turns out, narwhals - the precious unicorns of the sea - use their horns for hunting. But not how you’d think.

17. Human activity has literally changed the space surrounding our planet - decades of Very Low Frequency (VLF) radio communications have accidentally formed a protective, human-made bubble around Earth.

18. Farmers routinely feed red Skittles to their cattle, because it’s a cheap alternative to corn. ¯\_(ツ)_/¯

Proof without words - Pi

This was intended to be posted on Pi-day earlier this month, but somehow that didn’t happen.

Hope this beautiful pi gif on this sizzling Saturday puts a smile on your face and guides you through the day.

Have a good one!

Photo credit: Lucas V. Barbosa via Wikimedia Commons

** FYP’s Pi-day post ( if you are interested )