My professional blog with thoughts about microcontrollers, computer programming, and machine control.

 

trigonometry-is-my-bitch:

How a hole is drilled to be made square. The red shape in the center would be the cutting tool.
it shares the same principle as a Reuleaux triangle but with one rounded corner so that the cut square does not have rounded edges; the cutting tool follows the path of the rounded edge that is tangent to the sides of the outer square. because a tangent line is perpendicular to the radius, as the cutting tool follows the path of the rounded edge it turns precisely 90° to create a sharp edged perfect square.

trigonometry-is-my-bitch:

How a hole is drilled to be made square. The red shape in the center would be the cutting tool.

it shares the same principle as a Reuleaux triangle but with one rounded corner so that the cut square does not have rounded edges; the cutting tool follows the path of the rounded edge that is tangent to the sides of the outer square. because a tangent line is perpendicular to the radius, as the cutting tool follows the path of the rounded edge it turns precisely 90° to create a sharp edged perfect square.

techhive:

Chat off the grid: goTenna lets you send texts without cellular service
Towers schmowers! This portable RF antenna lets your phone work like a walkie-talkie, sending messages and GPS coordinates with no cellular connection required.

Let this be noted as the first steps to a second internet, a system independent of government/corporation.  A net of people, uncontrolled, private, and free.  A background app could act as a repeater to selectively forward messages similar to the way TCP/IP works for the internet, inside switches and routers.  With enough users and available frequencies, this gizmo could make for some huge changes.
To those with the technical know-how, run with it.

techhive:

Chat off the grid: goTenna lets you send texts without cellular service

Towers schmowers! This portable RF antenna lets your phone work like a walkie-talkie, sending messages and GPS coordinates with no cellular connection required.

Let this be noted as the first steps to a second internet, a system independent of government/corporation.  A net of people, uncontrolled, private, and free.  A background app could act as a repeater to selectively forward messages similar to the way TCP/IP works for the internet, inside switches and routers.  With enough users and available frequencies, this gizmo could make for some huge changes.

To those with the technical know-how, run with it.

cnce:

ABB Robotics - Introducing a new era of robotics

fuckyeahfluiddynamics:

Paint is probably the Internet’s second favorite non-Newtonian fluid to vibrate on a speaker—after oobleck, of course. And the Slow Mo Guys' take on it does not disappoint: it's bursting (literally?) with great fluid dynamics. It all starts at 1:53 when the less dense green paint starts dimpling due to the Faraday instability. Notice how the dimples and jets of fluid are all roughly equally spaced. When the vibration surpasses the green paint’s critical amplitude, jets sprout all over, ejecting droplets as they bounce. At 3:15, watch as a tiny yellow jet collapses into a cavity before the cavity’s collapse and the vibration combine to propel a jet much further outward. The macro shots are brilliant as well; watch for ligaments of paint breaking into droplets due to the surface-tension-driven Plateau-Rayleigh instability. (Video credit: The Slow Mo Guys)

reginageorqee:

Aerogel, also know as frozen smoke, is the world’s lowest density solid, clocking in at 96% air. If you hold a small piece in your hand, it’s practically impossible to either see or feel, but if you poke it, it’s like styrofoam. It supports up to 4,000 times its own weight and can withstand a direct blast from two pounds of dynamite. It’s also the best insulator in existence. Pretty amazing

reginageorqee:

Aerogel, also know as frozen smoke, is the world’s lowest density solid, clocking in at 96% air. If you hold a small piece in your hand, it’s practically impossible to either see or feel, but if you poke it, it’s like styrofoam. It supports up to 4,000 times its own weight and can withstand a direct blast from two pounds of dynamite. It’s also the best insulator in existence. Pretty amazing

(Source: fridaie)

fuckyeahfluiddynamics:

The flapping of flexible objects like flags have long fascinated mankind. The figure above from Shelley and Zhang 2011 shows several possible flapping states.  In (a) a thread immersed in a running soap film displays the standard von Karman vortex street of shed vortices in its wake. Parts (b) and (c) show the thread in coherent flapping motion; (b) shows an snapshot of the flapping thread in the soap film whereas (c) is a timelapse of the thread showing its full range of motion.  Image (d) shows the effects of a higher flow speed—the flapping motion becomes aperiodic. Image (e) shows a stiff metal wire bent into the shape of a flapping filament; note the strong boundary layer separation around the wire compared to the thread in Image (b). As one might expect, the drag on the unflapping wire is significantly greater than the drag on the flapping thread. (Image credit: M. Shelley and J. Zhang, Shelley and Zhang 2011)

fuckyeahfluiddynamics:

The flapping of flexible objects like flags have long fascinated mankind. The figure above from Shelley and Zhang 2011 shows several possible flapping states.  In (a) a thread immersed in a running soap film displays the standard von Karman vortex street of shed vortices in its wake. Parts (b) and (c) show the thread in coherent flapping motion; (b) shows an snapshot of the flapping thread in the soap film whereas (c) is a timelapse of the thread showing its full range of motion.  Image (d) shows the effects of a higher flow speed—the flapping motion becomes aperiodic. Image (e) shows a stiff metal wire bent into the shape of a flapping filament; note the strong boundary layer separation around the wire compared to the thread in Image (b). As one might expect, the drag on the unflapping wire is significantly greater than the drag on the flapping thread. (Image credit: M. Shelley and J. Zhang, Shelley and Zhang 2011)

ingenierodelmonton:

Diferentes maneras de obtener una elipse.

hypothesisfun:

Diferentes maneras de obtener una elipse

En matemáticas, una elipse es una curva en un plano que rodea dos puntos focales de tal manera que una línea recta trazada desde uno de los puntos focales a cualquier punto de la curva y luego de vuelta al otro punto focal tiene la misma longitud para cada punto de la curva. 

Hay muchas maneras diferentes de dar forma una elipse. Los anteriores son algunos ejemplos.

En orden:

  1. Una animación del trasmallo de Arquímides.
  2. Una animación de elipse de Van Schooten.
  3. Una elipse como un caso especial de un hipotrocoide.
  4. Animación de una curva que rodea dos focos.

¿Puedes pensar en otras maneras de formar una elipse?

(Source: visualizingmath)

sawdustnbones:

Saturday is a good start, but don’t stop there. Support the small artisans and craftsmen and women. Please repost this and show your support!

sawdustnbones:

Saturday is a good start, but don’t stop there.
Support the small artisans and craftsmen and women.
Please repost this and show your support!