15th Anniversary Sale
15th Anniversary Sale

Physics & Astronomy News

<p>How Gravity Can Bend Starlight</p>

<p>This illustration reveals how the gravity of a white dwarf star warps space and bends the light of a distant star behind it.</p>

<p>White dwarfs are the burned-out remnants of normal stars. The Hubble Space Telescope captured images of the dead star, called Stein 2051 B, as it passed in front of a background star. During the close alignment, Stein 2051 B deflected the starlight, which appeared offset by about 2 milliarcseconds from its actual position. This deviation is so small that it is equivalent to observing an ant crawl across the surface of a quarter from 1,500 miles away. From this measurement, astronomers calculated that the white dwarf's mass is roughly 68 percent of the sun's mass.</p>

<p>Stein 2051 B resides 17 light-years from Earth. The background star is about 5,000 light-years away. The white dwarf is named for its discoverer, Dutch Roman Catholic priest and astronomer Johan Stein.</p>
Observation confirms Einsteins general theory of relativity.
Astronomers have used NASA Hubble Space Telescope to repeat a century-old test of Einsteins general theory of relativity
<p>This image, taken by NASA's Hubble Space Telescope, reveals an unusual sight: a runaway quasar fleeing from its galaxy's central hub. A quasar is the visible, energetic signature of a black hole. Black holes cannot be observed directly, but they are the energy source at the heart of quasars — intense, compact gushers of radiation that can outshine an entire galaxy.</p>

<p>The green dotted line marks the visible periphery of the galaxy. The quasar, named 3C 186, appears as a bright star just off-center. The quasar and its host galaxy reside 8 billion light-years from Earth. Researchers estimate that it took the equivalent energy of 100 million supernovas exploding simultaneously to jettison the black hole. The most plausible explanation for this propulsive energy is that the monster object was given a kick by gravitational waves unleashed by the merger of two hefty black holes at the center of the host galaxy.</p>

<p>The Hubble image combines visible and near-infrared light taken by the Wide Field Camera 3.</p>

<p>Courtesy: NASA</p>
Gravitational Wave Kicks Monster Black Hole Out of Galactic Core
Astronomers have uncovered a supermassive black hole that has been propelled out of the center of a distant galaxy by what could be the awesome power of gravitational waves.

<p>Composite ALMA and optical image of a young Milky Way-like galaxy 12 billion light-years away and a background quasar 12.5 billion light-years away. Light from the quasar passed through the galaxy's gas on its way to Earth, revealing the presence of the galaxy to astronomers. New ALMA observations of the galaxy's ionized carbon (green) and dust continuum (blue) emission show that the dusty, star-forming disk of the galaxy is vastly offset from the gas detected by quasar absorption at optical wavelengths (red). This indicates that a massive halo of gas surrounds the galaxy. The optical data are from the Keck I Telescope at the W.M. Keck Observatory. Credit: ALMA (ESO/NAOJ/NRAO), M. Neeleman & J. Xavier Prochaska; Keck Observatory</p>
Milky Way-like Galaxies in Early Universe Embedded in 'Super Halos'
By harnessing the extreme sensitivity of the Atacama Large Millimeter/submillimeter Array (ALMA), astronomers have directly observed a pair of Milky Way-like galaxies seen when the universe was only eight percent of its current age.
<p>NEOS Detector</p>

<p>Courtesy: ibs</p>
Finding the 'Ghost Particles' Might be More Challenging
Results from the NEOS experiment on sterile neutrinos differ partly from the theoretical expectations.

Earth’s Magnetic Field Reveals Details Of A Dramatic Past
ESA’s Swarm satellites are seeing fine details in one of the most difficult layers of Earth’s magnetic field to unpick – as well as our planet’s magnetic history imprinted on Earth’s crust.
Scientists Evade The Heisenberg Uncertainty Principle
The study, published in Nature, reports a technique to bypass the Heisenberg uncertainty principle.
Using Light to Control Curvature of Plastics
Researchers have developed a technique that uses light to get two-dimensional (2-D) plastic sheets to curve into three-dimensional (3-D) structures, such as spheres, tubes or bowls.

Science Facts

Kinetic Theory of Gases

by NASA Glenn Research Center and

: Image Courtesy NIST Air is a gas, and gases can be studied by considering the small scale action of individual molecules or by considering the large scale action of the gas as a whole. We can directly measure, or sense, the action of the gas. But to study the action of the molecules, we must use a theoretical model. The model, called the kinetic theory of gases, assumes that the molecules are very small relative to the distance between molecules. The molecules are in constant, random motion and frequently collide with each other and with the walls of any container.

The individual molecules possess the standard physical properties of mass, momentum, and energy. The density of a gas is simply the sum of the mass of the molecules divided by the volume which the gas occupies. The pressure of a gas is a measure of the linear momentum of the molecules. As the gas molecules collide with the walls of a container, the molecules impart momentum to the walls, producing a force that can be measured. The force divided by the area is defined to be the pressure. The temperature of a gas is a measure of the mean kinetic energy of the gas. The molecules are in constant random motion, and there is an energy (mass x square of the velocity) associated with that motion. The higher the temperature, the greater the motion.

In a solid, the location of the molecules relative to each other remains almost constant. But in a gas, the molecules can move around and interact with each other and with their surroundings in different ways. As mentioned above, there is always a random component of molecular motion. The entire fluid can be made to move as well in an ordered motion (flow). The ordered motion is superimposed, or added to, the normal random motion of the molecules. At the molecular level, there is no distinction between the random component and the ordered component. In a pitot tube, we measure pressure produced by the random component as the static pressure, and the pressure produced by the random plus the ordered component as the total pressure.

NEAR animation of Eros
The Minor Planets

Asteroids are rocky fragments left over from the formation of the solar system about 4.6 billion years ago. Most of these fragments of ancient space rubble - sometimes referred to by scientists as min ...
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Microbes In Space

There are creatures that were living on the Space Station before the first astronauts went inside. Astronauts found a few living on the Moon. Scientists believe they could even live on Mars. These cre ...
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The appearance of Saturn
The Real Lord of the Rings

Why is Saturn the only planet with bright, easily seen rings? Saturn is not the only planet in our solar system with rings. Jupiter, Neptune and Uranus all have rings. Jupiter's rings are much smaller ...
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Science Quote

'All of us, are truly and literally a little bit of stardust.'

William Fowler

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