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Category: space – Page 347

Neutron Stars Create ‘Perfect’ Explosion in Space, Forming Senseless Symmetrical Sphere

Two neutron stars collided which caused a huge explosion but with an unusually flawless form, baffling scientists. Usually, a collision between neutron stars would lead to a flattened cloud but the recently observed explosion formed a perfectly spherical shape, SpaceAcademy.org reports.

It is still unclear how this is possible, but a new study may shed light on the fundamental physics involved and help scientists calculate the universe’s age. Astrophysicists from the Universe of Copenhagen discovered the kilonova and described it in full in their study, titled “Spherical Symmetry in the Kilonova At2017gfo/GW170817,” which was published in the journal Nature.

Reinforcement Learning Course — Full Machine Learning Tutorial

This is NOT for ChatGPT, but instead its the AI tech used in beating GO, Chess, DOTA, etc. In other words, not just generating the next best word based on reading billions of sentences, but planning out actions to beat real game opponents (and winning.) And it’s free.

Reinforcement learning is an area of machine learning that involves taking right action to maximize reward in a particular situation. In this full tutorial course, you will get a solid foundation in reinforcement learning core topics.

The course covers Q learning, SARSA, double Q learning, deep Q learning, and policy gradient methods. These algorithms are employed in a number of environments from the open AI gym, including space invaders, breakout, and others. The deep learning portion uses Tensorflow and PyTorch.

The course begins with more modern algorithms, such as deep q learning and policy gradient methods, and demonstrates the power of reinforcement learning.

Then the course teaches some of the fundamental concepts that power all reinforcement learning algorithms. These are illustrated by coding up some algorithms that predate deep learning, but are still foundational to the cutting edge. These are studied in some of the more traditional environments from the OpenAI gym, like the cart pole problem.

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The Planck Temperature: How hot can the Universe get?

The Planck Temperature – Absolute Hot: What is the hottest temperature possible.

Today I’m going to look at the Planck Temperature and it’s about to get very strange. Let’s find out more.

Planck temperature is what we think is the highest temperature possible. It is the temperature at which our understanding of the universe breaks.
In this video we’re going to try to imagine just how hot that is, and what the implications of this value are. In order to do this, we’re going to look at some other very hot things to compare.

Cup of tea image by TerriC
https://pixabay.com/photos/tea-cup-vintage-tea-cup-tea-cup-2107599/

Desert image by photo-graphe.
https://pixabay.com/photos/desert-landscape-sunset-dune-sand-2774945/

LHC tunnel image by Maximilien Brice at CERN, used under creative commons CC 4.0

Continue reading “The Planck Temperature: How hot can the Universe get?” | >

New type of bolometer detector for far-infrared telescopes

To study how stars and planets are born we have to look at star cradles hidden in cool clouds of dust. Far-infrared telescopes are able to pierce through those clouds. Conventionally, niobium nitride bolometers are used as the detectors, despite their low operating temperature of 4 Kelvin (−269° Celsius).

Now Yuner Gan (SRON/RUG), together with a team of scientists at SRON, TU Delft, Chalmers University and RUG, has developed a new type of bolometer, made of magnesium diboride, with an operating temperature of 20 Kelvin or above. This can significantly reduce the cost, complexity, weight and volume of the space instruments.

Conventional, superconducting niobium nitride (NbN) hot electron bolometers (HEBs) are so far the most sensitive heterodyne detectors for high-resolution spectroscopy at far-infrared frequencies. Heterodyne detectors take advantage of a local oscillator to convert a terahertz line into a gigahertz line.

Scientists observe high-speed star formation

Gas clouds in the Cygnus X Region, a region where stars form, are composed of a dense core of molecular hydrogen (H2) and an atomic shell. These ensembles of clouds interact with each other dynamically in order to quickly form new stars. That is the result of observations conducted by an international team led by scientists at the University of Cologne’s Institute of Astrophysics and at the University of Maryland.

Until now, it was unclear how this process precisely unfolds. The Cygnus X region is a vast luminous cloud of gas and dust approximately 5,000 light years from Earth. Using observations of spectral lines of ionized carbon (CII), the scientists showed that the clouds have formed there over several million years, which is a fast process by astronomical standards. The results of the study, “Ionized carbon as a tracer for the assembly of interstellar clouds,” will appear in the next issue of Nature Astronomy.

The observations were carried out in an international project led by Dr. Nicola Schneider at the University of Cologne and Prof Alexander Tielens at the University of Maryland as part of the FEEDBACK program on board the flying observatory SOFIA (Stratospheric Observatory for Infrared Astronomy). The new findings modify previous perceptions that this specific process of star formation is quasi-static and quite slow. The dynamic formation process now observed would also explain the formation of particularly massive stars.