The United Engineering Center, 345 E. 47th Street, New York City, Was Headquarters To The Major Engineering

Poor Alex :(. If you don’t get it, you can’t be an engineer 😂.

charles babbage: father of the computer (1970)

Pumping air through a bed of sand can make the grains behave just like a liquid. This process is called fluidization. Air introduced at the bottom of the bed forces its way upward through the sand grains. With a high flow rate, the space between sand grains gets larger, eventually reaching a point where the aerodynamic forces on a grain of sand equal gravitational forces. At this point the sand grains are essentially suspended in the air flow and behave like a fluid themselves. Light, buoyant objects – like the red ball above – can float in the fluidized sand; heavier, denser objects will sink. Fluidization has many useful properties – like good mixing and large surface contact between solid and fluid phases – that make it popular in industrial applications. For a similar (but potentially less playful) process, check out soil liquefaction. (Image credits: R. Cheng, source; via Gizmodo; submitted by Justin)

     Smithsonian’s National Air & Space Museum Udvar-Hazy Center in Chantilly, Virginia, offers the unique sight of a complete Mercury spacecraft. Many of these spacecraft are available for viewing all over the United States, but this one is special because it did not fly.

     During the course of a Mercury flight, several parts of the spacecraft are jettisoned and not recovered, including the retro package. This piece of equipment is visible here in my photos as the striped metal object strapped to the bottom of the heat shield. This small cluster of solid rocket motors was responsible for the safe return of the astronaut from space, making just enough thrust to change the shape of the orbit so that it would meet the atmosphere and use aerobraking for a ballistic reentry.

     If this package had not fired properly, the astronaut would be faced with the dire situation of being stuck in orbit. Fortunately, this never happened in real life, but it was captured in the fanciful novel “Marooned” by Martin Cardin, in which a NASA astronaut was stranded on orbit after his retro rockets failed. When the book was released in 1964, it was so influential that it actually changed procedures for Mercury’s follow on program Project Gemini, adding more redundancy to the spacecraft’s reentry flight profile.

     Alan Shepard, the first American in space and later Apollo 14 moonwalker, didn’t fail to notice that there was a leftover spacecraft at the end of the Mercury program. He lobbied for a second Mercury flight in this ship, speaking personally to both NASA Administrator James Webb and President John Kennedy about this flight. He told them his idea of an “open ended” mission in which they would keep him in orbit indefinitely until there was a malfunction or consumables began to run out. Webb stated (and Kennedy agreed) that it was more important to shelve the Mercury spacecraft in order to jump start the more capable Gemini Program. Thus, we now have this whole Mercury on display for future generations to appreciate.

“Imagine the earth to be a bag of rubber filled with water, a small quantity of which is periodically forced in and out of the same by means of a reciprocating pump, as illustrated. If the strokes of the latter are effected in intervals of more than one hour and forty-eight minutes, sufficient for the transmission of the impulse thru the whole mass, the entire bag will expand and contract and corresponding movements will be imparted to pressure gauges or movable pistons with the same intensity, irrespective of distance. By working the pump faster, shorter waves will be produced which, on reaching the opposite end of the bag, may be reflected and give rise to stationary nodes and loops, but in any case, the fluid being incompressible, its enclosure perfectly elastic, and the frequency of oscillations not very high, the energy will be economically transmitted and very little power consumed so long as no work is done in the receivers. This is a crude but correct representation of my wireless system in which, however, I resort to various refinements. Thus, for instance, the pump is made part of a resonant system of great inertia, enormously magnifying the force of the imprest impulses. The receiving devices are similarly conditioned and in this manner the amount of energy collected in them vastly increased.“

–Nikola Tesla

“Famous Scientific Illusions.” Electrical Experimenter, February, 1919.

Have you ever wondered just how detergents are able to get grease and oil off a surface? This simple example demonstrates one method. In the top image, a drop of oil sits attached to a solid surface; both are immersed in water. An eyedropper injects a surfactant chemical near the oil drop. This lowers the surface tension of the surrounding water and allows the mixture to better wet the solid. That eats away at the oil drop’s contact with the surface. It takes awhile – the middle animation is drastically sped up – but the oil droplet maintains less and less contact with the surface as the surfactant works. Eventually, in the bottom image, most of the oil drop detaches from the surface and floats away.   (Image credits: C. Kalelkar and A. Sahni, source)

Dawn O'Mara sitting on the edge of the front cockpit of a de Havilland DH82 Tiger Moth biplane, circa 1953.

Technical drawings of an F4U Corsair

You cannot drown in Quick Sand!

No! Seriously. You cannot. 

But I saw it in the movies or in the cartoon (C’mon bro, cartoon?). The gimmick that movies bring in, phew! They sometime just butcher the science out of things for entertainment.

What is Quick Sand? 

Remember Oobleck, the non- newtonian fluid that hardens on the application of force?

Well, Quick Sand ( also a non-newtonian fluid ) liqueifies on the application of force.

Why you can’t sink?

Quicksand itself is harmless: a human or animal is unlikely to sink entirely into quicksand at all due to the higher density of the fluid ( It has twice the density of human )

It’s the same reason why a ship although made up of steel, yet stays afloat at sea. “The heavier the fluid, the better things float.”

But for the ship to sink it has to push aside some water, which has nowhere to go but up. So it’s a question: does the ship ‘want’ to sink more than the water ‘wants’ not to rise?

It turns out that just depends on whether the ship weighs more or less than the amount of water that would fill the same space. Real ships have lots of air inside, so they weigh less than the same volume of water, so they float.

Getting out of it albeit,  is a real pain.

That being said, it is no joke that people have lost their lives in Quicksand. But the rationale for their death is often misattributed.

It’s not the quicksand that will kill you, but the sunlight, dehydration, carnivores, omnivores, hypothermia or tides that will.

It takes a feat of strength to get out of one though.

A study published in Nature found that the force needed to pull your foot out of quicksand at a speed of one centimentre per second would be equivalent to lifting a medium-sized car (in air).

So,How do you get out of it?

Well, who would be a better person to explain it than Bear Grylls himself.

Getting out of a Quicksand with Bear Grylls.

F1 is more than just racing, it is an engineering battle. In this gif you can see the absolute control of wing tip vortices generated from the front wing. This is just an example to show the extreme aerodynamics that these vehicles are engineered for.

Have a great day!

* What are wing tip vortices ?

** Smoke angels and wing tip vortices