Distant Galaxy Collision Imaged Through Gravitational Lensing

The European Southern observatory and with the help of other agencies, has imaged a galactic collission that happened when the Universe was half its age using gravitational lensing.

Using state of the art instruments from all around the world, on the ground and in space, ESO has imaged galaxy H-ATLAS J142935.3-002836 in collision with another galaxy.

With the help of gravitational lensing which uses Einstein's theory that light can be bent given enough mass, scientists were able to study objects which would not be visible otherwise and to directly compare local galaxies with much more remote ones, seen when the Universe was significantly younger.

The image above shows the foreground galaxy that is doing the lensing, which resembles how our home galaxy, the Milky Way, would appear if seen edge-on. But around this galaxy there is an almost complete ring — the smeared out image of a star-forming galaxy merger far beyond.

In his theory of general relativity, Einstein predicted that given enough mass, light does not travel in a straight line but will be bent in a similar way to light refracted by a normal lens.”

Gravitational lensing is done with the help of galaxies and galaxy clusters which provides the mass that deflects light from objects behind them due to their strong gravity. The magnifying properties of this effect allow astronomers to study these objects.

The collision of H-ATLAS J142935.3-002836 was gathered using three ESO telescopes, the ALMA, APEX and VISTA, and with assistance of other telescopes and surveys namely: NASA/ESA Hubble Space Telescope, the Gemini South telescope, the Keck-II telescope, the NASA Spitzer Space Telescope, the Jansky Very Large Array, CARMA, IRAM and SDSS and WISE.

Gravitational Waves Give Insight To Growth of Supermassive Black Holes

CSIRO Parkes Radio Telescope

Scientists are looking at gravitational waves to understand the growth of supermassive black holes.

Black holes are regions in space where gravity is so strong that nothing, not even light, can resist its pull. It is believed that every galaxy has a supermassive black hole (SMBH) in its center.

Gravitational waves can best be described as small waves or ripples that travel through the fabric of space-time. It is like putting a bowling bowl on a mattress and rolling it forward. The indentations surrounding the bowling ball as it rolls can be described as a gravitational wave.

Einstein theorized that similar to the mattress, the dimension of space-time warps and curves as planets and other objects of big masses move along it. These curvatures generate ripples (waves) in space-time that travel outward at the speed of light and diminishes in energy as it goes further out.

Although gravitational waves have not yet been directly discovered, there have been indirect observations of its existence using radio signals from a pulsar.

In this latest study, scientists believe that by studying the connection between the strength of a gravitational wave and how two colliding supermassive blackholes behave (their mass, distance between each other and how often it spirals and merge), it will help explain the growth of black holes.

White Dwarf Star Orbiting A Pulsar Discovered By ESO's VLT

Astronomers have used ESO’s Very Large Telescope, along with radio telescopes around the world, to find and study a bizarre stellar pair consisting of the most massive neutron star confirmed so far, orbited by a white dwarf star. This strange new binary allows tests of Einstein’s theory of gravity — general relativity — in ways that were not possible up to now. So far the new observations exactly agree with the predictions from general relativity and are inconsistent with some alternative theories. The results will appear in the journal Science on 26 April 2013.

Scientists using the European Southern Observatory's Very Large Telescope (VLT) has discovered an unusual pairing; a white dwarf star orbiting a neutron star (PSR J0348+0432). The neutron star is a pulsar around 20 kilometres across but is two times heavier than the Sun. This discovery and the observation of how the two stellar objects behave is how Einstein's Theory of General Relativity predicted it would behave.

A white dwarf star is a small star which is very dense and is mostly made up of electron-degenerate matter. It is a star that has reached the end of its normal life cycle and has stopped nuclear fusion (although some fusion reactions happen and can still generate energy). A white dwarf star may be as big as the Earth but has the same mass as that of the Sun.

A pulsar is a neutron star that is formed when a massive star's core is compressed during a super nova. This event collapses the core and forms the neutron star. Pulsars are extermely dense and highly magnetized. They rotate and emit a beam of electromagnetic radiation. This radiation is picked up as radio waves in the form of pulses. The name pulsar is abbreviated from the term "pulsating star".

Using 'Hidden Influence Inequality' To Explain Quantum Nonlocality

In 1964, physicist John Stewart Bell published his paper, "On the Einstein Podolsky Rosen paradox". In the paper, he derived his theorem, Bells Theorem, that states that - No physical theory of local hidden variables can ever reproduce all of the predictions of quantum mechanics. Local hidden variables refers to realism and the local causality theory where combined, it meant that distant events are assumed to have no instantaneous (or at least faster-than-light) effect on local ones.

This meant that classical mechanics cannot explain everything that is going on in quantum mechanics.