Determining the shape of cells

Cells are constantly performing small tasks such as repairing wounds. They exert force by changing shape. But how do cells translate their shape into exerting a force in a specific direction? Experimental and theoretical ...

'Weirdest martensite': Century-old smectic riddle finally solved

Using the latest computer game technology, a Cornell-led team of physicists has come up with a "suitably beautiful" explanation to a puzzle that has baffled researchers in the materials and theoretical physics communities ...

Video simulation puts a new twist on fusion plasma research

Samuel Lazerson, an associate research physicist in advanced projects at the U.S. Department of Energy's Princeton Plasma Physics Laboratory (PPPL), has created a video simulation showing the intricate nature of a plasma ...

Super full moon

Mark your calendar. On March 19th, a full Moon of rare size and beauty will rise in the east at sunset. It's a super "perigee moon"--the biggest in almost 20 years.

Biggest Full Moon of the Year: Take 2

When last month's full Moon rose over Florida, onlooker Raquel Stanton of Cocoa Beach realized that something was up.


In geometry, an ellipse (from Greek ἔλλειψις elleipsis, a "falling short") is a plane curve that results from the intersection of a cone by a plane in a way that produces a closed curve. Circles are special cases of ellipses, obtained when the cutting plane is orthogonal to the cone's axis. An ellipse is also the locus of all points of the plane whose distances to two fixed points add to the same constant.

Ellipses are closed curves and are the bounded case of the conic sections, the curves that result from the intersection of a circular cone and a plane that does not pass through its apex; the other two (open and unbounded) cases are parabolas and hyperbolas. Ellipses arise from the intersection of a right circular cylinder with a plane that is not parallel to the cylinder's main axis of symmetry. Ellipses also arise as images of a circle under parallel projection and the bounded cases of perspective projection, which are simply intersections of the projective cone with the plane of projection. It is also the simplest Lissajous figure, formed when the horizontal and vertical motions are sinusoids with the same frequency.

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