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Archive for the ‘space’ category: Page 658

Jun 14, 2020

Exploring chemical compound space with quantum-based machine learning

Posted by in categories: chemistry, quantum physics, robotics/AI, space

Rational design of compounds with specific properties requires understanding and fast evaluation of molecular properties throughout chemical compound space — the huge set of all potentially stable molecules. Recent advances in combining quantum-mechanical calculations with machine learning provide powerful tools for exploring wide swathes of chemical compound space. We present our perspective on this exciting and quickly developing field by discussing key advances in the development and applications of quantum-mechanics-based machine-learning methods to diverse compounds and properties, and outlining the challenges ahead. We argue that significant progress in the exploration and understanding of chemical compound space can be made through a systematic combination of rigorous physical theories, comprehensive synthetic data sets of microscopic and macroscopic properties, and modern machine-learning methods that account for physical and chemical knowledge.

Jun 14, 2020

Cornerstone of Einstein’s Theory of Relativity Confirmed

Posted by in categories: physics, space

An international collaboration of scientists has recorded the most accurate confirmation to date for one of the cornerstones of Einstein’s theory of general relativity, ‘the universality of free fall.’

The new research shows that the theory holds for strongly self-gravitating objects such as neutron stars. Using a radio telescope, scientists can very accurately observe the signal produced by pulsars, a type of neutron star and test the validity of Einstein’s theory of gravity for these extreme objects. In particular, the team analyzed the signals from a pulsar named ‘PSR J0337+1715’ recorded by the large radio telescope of Nançay, located in the heart of Sologne (France).

The universality of free fall principle states that two bodies dropped in a gravitational field undergo the very same acceleration independently of their composition. This was first demonstrated by Galileo who famously would have dropped objects of different masses from the top of Pisa’s tower to verify that they both reach the ground simultaneously.

Jun 14, 2020

Episode 2 — The Mysteries of Our Planet Venus

Posted by in categories: evolution, space, sustainability

Please listen to the second episode of my new Cosmic Controversy Podcast. This week’s guest is planetary scientist Stephen Kane at the University of California, Riverside, who discusses why Venus is so haunting and beguiling all at once.


In this wide-ranging interview, planetary scientist Stephen Kane of the University of California, Riverside, delves into the mysteries of our neighbor planet Venus. We discuss how Venus went wrong and why understanding its evolution is so important in characterizing extrasolar planetary systems like our own.

Jun 14, 2020

Icarus, Much? This Aircraft Aims to Fly to Space Using Only Energy From the Sun

Posted by in categories: solar power, space, sustainability

The SolarStratos will gain its power from 240 square feet of solar panels on its wings.

Jun 14, 2020

NASA Johnson Style (Gangnam Style Parody)

Posted by in categories: entertainment, space

#NASA

#SpaceFun


#NASA #SpaceFun

Jun 14, 2020

Behind the Spacecraft – Perseverance – The Next Mars Rover

Posted by in category: space

Sending a rover to the Red Planet is more than just 3…2…1… Liftoff! 🚀 It takes 1,000s of people and years of hard work to get a spacecraft from Earth to Mars. So when NASA’s Perseverance Mars Rover touches down on the Martian surface, it will be because of the talented NASA minds that helped to make it happen.

Follow the journey of Perseverance: mars.nasa.gov/mars2020

Jun 13, 2020

Scientists close in on 12-billion-year-old signal from the end of the universe’s ‘dark age’

Posted by in category: space

Today, stars fill the night sky. But when the universe was in its infancy, it contained no stars at all. And an international team of scientists is closer than ever to detecting, measuring and studying a signal from this era that has been traveling through the cosmos ever since that starless era ended some 13 billion years ago.

That team—led by researchers at the University of Washington, the University of Melbourne, Curtin University and Brown University—reported last year in the Astrophysical Journal that it had achieved an almost 10-fold improvement of radio emission data collected by the Murchison Widefield Array. Team members are currently scouring the data from this radio telescope in remote Western Australia for a telltale signal from this poorly understood “” of our universe.

Learning about this period will help address major questions about the universe today.

Jun 12, 2020

Exotic fifth state of matter made on the International Space Station

Posted by in categories: particle physics, space

An instrument on board the International Space Station contains one of the coldest places in the universe, and researchers have used it to create a cloud of frozen atoms.

Jun 11, 2020

Extremely brilliant giga-electron-volt gamma rays from a two-stage laser-plasma accelerator

Posted by in categories: engineering, particle physics, space

Laser-wakefield accelerators have led to the development of compact, ultrashort X-ray or gamma-ray sources to deliver peak brilliance, similar to conventional synchrotron sources. However, such sources are withheld by low efficiencies and limited to 107–8 photons per shot in the kiloelectron volt (KeV) to megaelectron volt (MeV) range. In a new report now published on Science Advances, Xing-Long Zhu and a research team in physics and astronomy in China and the U.K., presented a new approach to efficiently produce collimated, ultrabright gamma (γ)-ray beams. The resulting photon energies were tunable for up to gigaelectron volts by focussing a multi-petawatt laser pulse into a 2-stage wakefield accelerator. The high-intensity laser allowed them to efficiently generate a multi-gigaelectron volt electron beam with a high density and charge during the first stage of the experiment. The laser and electron beams entered a high-density plasma region in the second stage thereafter. Using numerical simulations, they demonstrated the production of more than 1012 gamma ray photons per shot with energy conversion efficiency above 10 percent for photons above 1 megaelectron volt (MeV) and achieved a peak brilliance above 1026 photons S-1 mm-2 mrad-2 per 0.1 percent bandwidth at 1 MeV. This research outcome will offer new avenues in both fundamental and applied physics and engineering.

Bright sources of high-energy gamma rays are versatile for broad areas of applications, including fundamental research in astrophysics, particle and nuclear physics, as well as high-resolution imaging. Researchers can improve such applications with compact gamma ray sources with low divergence, short pulse duration, high energy, and high peak brilliance. While widely used synchrotrons and X-ray free electron lasers (XFELS) can deliver X-ray pulses with peak brilliance, they are limited to low photon energies. The size and cost of such research structures can also limit their regular applications. Researchers have therefore rapidly developed compact laser-wakefield accelerators (LWFAs) in the past two decades to offer a radically different approach to drive the acceleration and radiation of high-energy particles on a much smaller scale. Continuous advancements in the field of ultrahigh-power laser technology will enable brilliant high-energy gamma sources.

Jun 10, 2020

Possible periodic activity in the repeating FRB 121102

Posted by in category: space

The discovery that at least some Fast Radio Bursts (FRBs) repeat has ruled out cataclysmic events as the progenitors of these particular bursts. FRB 121102 is the most well-studied repeating FRB but despite extensive monitoring of the source, no underlying pattern in the repetition has previously been identified. Here, we present the results from a radio monitoring campaign of FRB 121102 using the 76 m Lovell telescope. Using the pulses detected in the Lovell data along with pulses from the literature, we report a detection of periodic behaviour of the source over the span of 5 yr of data. We predict that the source is currently ‘off’ and that it should turn ‘on’ for the approximate MJD range 59002–59089 (2020 June 2 to 2020 August 28). This result, along with the recent detection of periodicity from another repeating FRB, highlights the need for long-term monitoring of repeating FRBs at a high cadence. Using simulations, we show that one needs at least 100 h of telescope time to follow-up repeating FRBs at a cadence of 0.5–3 d to detect periodicities in the range of 10–150 d. If the period is real, it shows that repeating FRBs can have a large range in their activity periods that might be difficult to reconcile with neutron star precession models.

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