Archive for the ‘physics’ category: Page 2

Oct 27, 2019

There’s a chance the black hole at the center of our galaxy is actually a wormhole

Posted by in categories: cosmology, physics

Science fiction writers love wormholes because they make the impossible possible, linking otherwise unreachable places together. Enter one, and it’ll spit you back out in another locale—typically one that’s convenient for the plot. And no matter how unlikely these exotic black hole relatives are to exist in reality, they tend to fascinate physicists for exactly the same reason. Recently, some of those physicists took the time to ponder what such a cosmic shortcut might look like in real life, and even make a case that there could be one at the center of our galaxy.

Oct 26, 2019

Rapid laser solver for the phase retrieval problem

Posted by in categories: computing, information science, physics, space

Physicists can explore tailored physical systems to rapidly solve challenging computational tasks by developing spin simulators, combinatorial optimization and focusing light through scattering media. In a new report on Science Advances, C. Tradonsky and a group of researchers in the Departments of Physics in Israel and India addressed the phase retrieval problem by reconstructing an object from its scattered intensity distribution. The experimental process addressed an existing problem in disciplines ranging from X-ray imaging to astrophysics that lack techniques to reconstruct an object of interest, where scientists typically use indirect iterative algorithms that are inherently slow.

In the new optical approach, Tradonsky et al conversely used a digital degenerate cavity laser (DDCL) mode to rapidly and efficiently reconstruct the object of interest. The experimental results suggested that the gain competition between the many lasing modes acted as a highly parallel computer to rapidly dissolve the phase retrieval problem. The approach applies to two-dimensional (2-D) objects with known compact support and complex-valued objects, to generalize imaging through scattering media, while accomplishing other challenging computational tasks.

To calculate the intensity distribution of light scattered far from an unknown object relatively easily, researchers can compute the source of the absolute value of an object’s Fourier transform. The reconstruction of an object from its scattered intensity distribution is, however, ill-posed, since phase information can be lost and diverse phase distributions in the work can result in different reconstructions. Scientists must therefore obtain prior information about an object’s shape, positivity, spatial symmetry or sparsity for more precise object reconstructions. Such examples are found in astronomy, short-pulse characterization studies, X-ray diffraction, radar detection, speech recognition and when imaging across turbid media. During the reconstruction of objects with a finite extent (compact support), researchers offer a unique solution to the phase retrieval problem, as long as they model the same scattered intensity at a sufficiently higher resolution.

Oct 25, 2019

Physicists simulate critical ‘reheating’ period that kickstarted the Big Bang

Posted by in categories: cosmology, physics

As the Big Bang theory goes, somewhere around 13.8 billion years ago the universe exploded into being, as an infinitely small, compact fireball of matter that cooled as it expanded, triggering reactions that cooked up the first stars and galaxies, and all the forms of matter that we see (and are) today.

Just before the Big Bang launched the universe onto its ever-expanding course, physicists believe, there was another, more explosive phase of the early universe at play: cosmic inflation, which lasted less than a trillionth of a second. During this period, matter—a cold, homogeneous goop—inflated exponentially quickly before processes of the Big Bang took over to more slowly expand and diversify the infant universe.

Recent observations have independently supported theories for both the Big Bang and cosmic inflation. But the two processes are so radically different from each other that scientists have struggled to conceive of how one followed the other.

Oct 24, 2019

How Fast Is The Universe Expanding? Incompatible Answers Point To New Physics

Posted by in categories: physics, space

As more data comes in, the puzzle gets deeper and deeper.

Oct 24, 2019

Be the first to comment on “How to Spot a Wormhole – Physicists Describe a Technique for Detecting Spacetime Bridges”

Posted by in categories: cosmology, physics

In a theoretical study, physicists propose that perturbations in the orbit of stars near supermassive black holes could be used to detect wormholes.

A new study outlines a method for detecting a speculative phenomenon that has long captured the imagination of sci-fi fans: wormholes, which form a passage between two separate regions of spacetime.

Such pathways could connect one area of our universe to a different time and/or place within our universe, or to a different universe altogether.

Oct 24, 2019

How to spot a wormhole (if they exist)

Posted by in categories: cosmology, physics

A new study outlines a method for detecting a speculative phenomenon that has long captured the imagination of sci-fi fans: wormholes, which form a passage between two separate regions of spacetime.

Such pathways could connect one area of our universe to a different time and/or place within our universe, or to a different universe altogether.

Whether wormholes exist is up for debate. But in a paper published on Oct. 10 in Physical Review D, physicists describe a technique for detecting these bridges.

Oct 23, 2019

First identification of a heavy element born from neutron star collision

Posted by in categories: physics, space

For the first time, a freshly made heavy element, strontium, has been detected in space, in the aftermath of a merger of two neutron stars. This finding was observed by ESO’s X-shooter spectrograph on the Very Large Telescope (VLT) and is published today in Nature. The detection confirms that the heavier elements in the Universe can form in neutron star mergers, providing a missing piece of the puzzle of chemical element formation.

In 2017, following the detection of gravitational waves passing the Earth, ESO pointed its telescopes in Chile, including the VLT, to the source: a star merger named GW170817. Astronomers suspected that, if did form in neutron star collisions, signatures of those elements could be detected in kilonovae, the explosive aftermaths of these mergers. This is what a team of European researchers has now done, using data from the X-shooter instrument on ESO’s VLT.

Following the GW170817 merger, ESO’s fleet of telescopes began monitoring the emerging kilonova explosion over a wide range of wavelengths. X-shooter in particular took a series of spectra from the ultraviolet to the near infrared. Initial analysis of these spectra suggested the presence of heavy elements in the kilonova, but astronomers could not pinpoint individual elements until now.

Oct 22, 2019

Physicists Create Unexpected New Form of Plutonium

Posted by in category: physics

Physicists using the European Synchrotron Radiation Facility have created a new compound of plutonium (Pu) with an unexpected, pentavalent oxidation state — Pu (V). The new compound is solid and stable, and may represent a transient phase in radioactive waste repositories.

Oct 18, 2019

Scientists may have discovered parallel universe

Posted by in categories: astronomy, cosmology, physics, science, space

Scientists believe they may have caught a glimpse of a parallel universe bumping up against ours.

They’ve seen hints in signals from the most distant points of the universe that suggest the fabric of our universe has been disrupted by another incredibly different universe. Their analysis may be the proof for the multiverse theory.

According to researchers: “Dr Ranga-Ram Chary examined the noise and residual signals in the cosmic microwave background left over from the Big Bang (pictured) and found a number of scattered bright spots which he believes may be signals of another universe bumping into our own billions of years ago.”

At least that’s the tentative conclusion researchers have come to. According to some cosmological theories, collisions of alternative universes should be possible. Theories conclude that our universe is like a bubble among many.

Continue reading “Scientists may have discovered parallel universe” »

Oct 15, 2019

Faster-Than-Light Travel Could Explain Mysterious Signals Beaming Through the Cosmos

Posted by in category: physics

But don’t worry, no laws of physics are being violated.

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