Physics & Astronomy News

<p>An artist’s conception of this unusual system, courtesy of Jonathan Holden/Disk Detective.</p>
Oldest Known Planet-Forming Disk Found
Scientists find a star surrounded by the oldest known circumstellar disk—a primordial ring of gas and dust that orbits around a young star and from which planets can form.
<p>Mars’ Valles Marineris canyon, pictured, spans as much as 600 kilometers across and delves as much as 8 kilometers deep. The image was created from over 100 images of Mars taken by Viking Orbiters in the 1970s.</p>

<p>Image: NASA</p>
New Technique May Help Detect Martian Life
A novel interpretation of Raman spectra will help the 2020 Mars rover select rocks to study for signs of life.

<p>Simplification to represent PT (Parity-Time) symmetry. Imagine a situation where two cars are traveling at the same speed at some instant in time, but car A is speeding up, and car B is slowing down. In order to go at the same speed, you can jump from one car to the other (Parity reversal) and back in time (Time reversal). The cars are like the light waves inside the fiber, the speed of the cars is a representation of the intensity of light and the jump symbolizes a phenomenon called tunneling. (Graphics modified from freepiks).</p>
Stable Propagation of Light in Nano-Photonic Fibers
New model on how to achieve a more stable propagation of light for future optical technologies was published.
<p>Regime of a single 1D wire subband filled</p>

<p>Credit: Dr Maria Moreno</p>
Quantum Effects Observed in ‘One-Dimensional’ Wires
Researchers have observed quantum effects in electrons by squeezing them into one-dimensional ‘quantum wires’ and observing the interactions between them.

Echoes of Black Holes Eating Stars Found
Astronomers now have new insights into tidal disruption flares, thanks to data from NASA's Wide-field Infrared Survey Explorer (WISE).
Individual Atoms Behavior Observed
For first time, researchers see individual atoms keep away from each other or bunch up as pairs.
Gaia’s First Sky Map
The first catalogue of more than a billion stars from ESA’s Gaia satellite was published – the largest all-sky survey of celestial objects to date.

Science Facts

Newton's Three Laws of Motion

by NASA Glenn Research Center and

Sir Issac Newton: Image Courtesy Glenn Research Center The motion of an aircraft through the air can be explained and described by physical principals discovered over 300 years ago by Sir Isaac Newton. Newton worked in many areas of mathematics and physics. He developed the theories of gravitation in 1666, when he was only 23 years old. Some twenty years later, in 1686, he presented his three laws of motion in the 'Principia Mathematica Philosophiae Naturalis.' Newton's 1st law states that every object will remain at rest or in uniform motion in a straight line unless compelled to change its state by the action of an external force. This is normally taken as the definition of inertia. The key point here is that if there is no net force acting on an object (if all the external forces cancel each other out) then the object will maintain a constant velocity. If that velocity is zero, then the object remains at rest. If an external force is applied, the velocity will change because of the force.

The 2nd law explains how the velocity will change. The law defines a force to be equal to change in momentum (mass times velocity) per change in time. Newton also developed the calculus of mathematics, and the 'changes' expressed in the second law are accurately defined in differential forms. (Calculus can also be used to determine the velocity and location variations experienced by an object subjected to an external force.) For an object with a constant mass, the 2nd law can be more easily expressed as the product of an object's mass and its acceleration (F = ma). For an external applied force, the change in velocity depends on the mass of the object. A force will cause a change in velocity; and likewise, a change in velocity will generate a force. The equation works both ways.

The 3rd law states that for every action (force) in nature there is an equal and opposite reaction. In other words, if object A exerts a force on object B, then object B also exerts an equal force on object A. Notice that the forces are exerted on different objects. The third law can be used to explain the generation of lift by a wing and the production of thrust by a jet engine.

The Eccentric Spin of Uranus
The Strange Spin of Uranus

Directional terms like north and south make sense here on Earth. The north and south axis of the Earth is relatively perpendicular to the plane of the Earth's orbit around the sun. Actually, Earth's a ...
continue reading this fact
An artist
The Brave and Cold Ulysses

Deep space is cold. Very cold. That's a problem--especially if you're flying in an old spaceship. And your power supplies are waning. And the fuel lines could freeze at any moment. Oh, and by the way, ...
continue reading this fact

Introduction To Jupiter

With its numerous moons and several rings, the Jupiter system is a 'mini-solar system.' Jupiter is the most massive planet in our solar system, and in composition it resembles a small star. In fact, i ...
continue reading this fact

Science Quote

'Nothing in this world is to be feared... only understood.'

Marie Curie

All rights reserved. © Copyright '1995-'2016