How the Universe Works - Death of the Milky Way - Explore The Milky Way Galaxy

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The Might and Mystery of Black Holes - How the Universe Works

In science fiction, black holes are often portrayed as some kind of menacing threat to the safety of the whole Universe, like giant vacuum cleaners that suck up all of existence. Now, in this episode, we're going to separate the fiction from the facts and we're going to look at the real science behind black holes and how Hubble has contributed to it. Black holes come in different sizes. We've had solid evidence for the smaller ones since the 1970s. These form when a huge star explodes at the end of its life. As the outer layers are blown away, the star's core collapses in on itself forming an incredibly dense ball. For instance, a black hole with the same mass as the Sun would have a radius of only a few kilometres. These black holes won't suck you in unless you get very close to them though. In fact, contrary to popular belief, a black hole the size of the Sun doesn't actually exert any more gravitational pull than the Sun does. But these stellar black holes are just part of the story. Before Hubble was launched, astronomers had noticed that the centres of many galaxies were somehow much denser and brighter than they were expected to be. And so they speculated that there must be some kind of huge, massive objects lurking in the centres of these galaxies in order to provide the additional gravitational attraction. Now, could these objects be supermassive black holes, that is, black holes which are millions or even billions of times more massive than the stellar ones? Or was there perhaps a simpler, less exotic explanation, like giant star clusters? Frustratingly, at that time, telescopes just weren't quite powerful enough to see enough detail to solve the mystery. Fortunately, Hubble was on its way, along with a range of other high-tech telescopes. When the space telescope was being planned, the search for supermassive black holes was in fact one of its main objectives. Some of Hubble's early observations in the 1990s were dedicated to these dense, bright galactic centres. Where ground-based telescopes were just seeing a sea of stars, Hubble was able to resolve the details. In fact, around the very centres of these galaxies, Hubble discovered rotating discs of gas and dust. When Hubble observed the disc at the centre of a nearby galaxy, Messier 87, the astronomers saw that its colour was not quite the same on both sides. One side was shifted towards blue and the other towards red, and this told the scientists that it must have been rotating very quickly. This is because the wavelength of light is changed by the motion of an object emitting it. Think about how the pitch of an ambulance siren drops as it drives past you, because the sound waves are more spaced out as the vehicle moves away. Similarly, if an object is moving towards you, the light's wavelength is squashed, making it bluer; if it's moving away, it's stretched, making it redder. This is also known as the Doppler effect. So, by measuring how much the colours had shifted on either side of the disk, astronomers were able to determine its speed of rotation. And it turned out that this disk was spinning at a rate of hundreds of kilometres per second. This in turn allowed astronomers to deduce that, hidden at the very centre, there must be some kind of object which was two to three billion times the mass of our Sun — and this was very likely a supermassive black hole. Now, along with a lot of other observations, this was a key piece of evidence that led to the notion that there is a supermassive black hole lurking at the centre of most, if not all, giant galaxies, including our own Milky Way. So far, so good. But this work was almost 20 years ago — what does it tell us about cutting-edge science today? Well, the science of black holes has moved along a lot since then. The mystery now isn't whether they exist, but why they behave in the strange ways they do. For example, Hubble observations have helped to show that the mass of a black hole is closely related to the mass of its surrounding host galaxy. The bigger the black hole, the bigger the galaxy. Now the reason for this is totally unclear. #blackholes #Universe #Space

How Far Away Is It - 11 - Andromeda and the Local Group (1080p) see update

(Newer version at Text at In this segment of our "How far away is it" video book, we cover the Andromeda galaxy along with our local group of galaxies, including some of the dwarf galaxies orbiting the Milky Way. We begin with Edwin Hubble's discovery of a Cepheid variable star in what was thought to be a Milky Way nebula. The star was V1 and it changed the history of astronomy. We cover the black hole at the center of Andromeda, highlight the size of this beautiful galaxy with its trillion stars, and point out what was going on here on our planet when the light we see left Andromeda on its journey into our telescopes. Next we identify the local group of galaxies including: Triangulum with its great star birth H II region NGC 604; irregular galaxy NGC 6822 with its unique Hubble V H II region; the recently discovered galaxy IC 10; nearly edge on galaxy NGC 3109; and Sextans A. Then we focus on the two main galaxies orbiting the Milky Way -- the Large Magellanic Cloud and the Small Magellanic Cloud. Then we take a look at some of the amazing nebula within these two dwarf galaxies including: Supernova Remnant N 63A, SN 0509-67.5, the Tarantula Nebula, 30 Doradus, Hodge 301, the Double Bubble, LH 95, NGC 2074, NGC 602, and NGC 346. We conclude with a review of the galaxies we covered marked on a map of the Local Group. STEM

Mars Calling: Manifest Destiny or Grand Illusion

Hey Everyone, You can find our 4K UHD content and more great space and science shows on: This film brings together the mythic and the scientific to show that Mars may now be what we imagine. Some believe Mars is the next home for Humanity. But the real “red planet” is a trickster; strikingly beautiful, yet sweetly sinister. Even as a growing armada of instruments arrive, this small cold world continues to conceal its secrets. The technological means to cross space and perhaps bring this small world back to life is just now coming within our grasp. Settlers beware: Mars is likely to change Humanity as much as we change it.

The Milky Way as You’ve Never Seen It Before – AMNH SciCafe

Fly through the galaxy with Museum astrophysicist Jackie Faherty, who takes us on a dazzling tour of new research and data visualizations made possible by recently released data from the Gaia space telescope. In April 2018, the European Space Agency’s Gaia observatory released its second data catalog, which includes the distances to over 1.3 billion stars. Faherty breaks down why this information is so revolutionary, and explains how this information is helping scientists and non-scientists alike understand the universe like never before. Listen to the full SciCafe event, including a Q&A session, by downloading the [email protected] podcast on iTunes, Soundcloud, or wherever you get your podcasts. This SciCafe took place on October 3, 2018. The SciCafe series is proudly sponsored by Judy and Josh Weston. #Gaia #MilkyWay #Astronomy #Astrophysics #Telescope #Satellite #SciCafe #JackieFaherty #Exoplanets #Stars *** Subscribe to our channel: Check out our full video catalog: Facebook: ‪ ‬‬‬‬‬‬‬‬‬‬‬‬‬‬ Twitter: ‪ ‬‬‬‬‬‬‬‬‬‬‬‬‬‬ Tumblr: ‪‬‬‬‬‬‬‬‬‬‬‬‬‬‬ Instagram: ‪‬‬‬‬‬‬‬‬‬‬‬‬‬‬ This video and all media incorporated herein (including text, images, and audio) are the property of the American Museum of Natural History or its licensors, all rights reserved. The Museum has made this video available for your personal, educational use. You may not use this video, or any part of it, for commercial purposes, nor may you reproduce, distribute, publish, prepare derivative works from, or publicly display it without the prior written consent of the Museum. © American Museum of Natural History, New York, NY

Rain & Fog in the Forest | Relaxing Sleep Sounds for Stress Relief, Insomnia Symptoms & Anxiety

Rain sounds and fog in the forest. Relaxing sleep sounds for stress relief, insomnia symptoms, anxiety attacks or soothing a baby (24/7). Listen to the gentle rainfall through the leaves and foggy mist as you drift off to sleep at night. Nature sounds create natural white noise which can help calm your mind and body. White noise drowns out distracting background noises so that you can sleep better at night. It contains a mixture of different frequencies that when combined helps your brain to relax. Your brain is programmed to identify patterns. As white sounds do not have any distinct patterns your mind gives up and relaxes, assuming that the environment is safe to sleep. We hope you enjoy these soothing raining sounds in the foggy forest. These sleep sounds are great for stress relief, insomnia, anxiety attacks, study or even soothing a baby! Stardust Vibes - Relaxing Sounds 😊 🌀 MP3 DOWNLOADS: 🌀 SLEEP HELP: 🌀 FACEBOOK: 🌀 INSTAGRAM: 🌀 TWITTER: 🌀 YOUTUBE SUBSCRIBE: #rain #fog #sleep DISCLAIMER: This video should not be used to replace any medical or psychological treatment. If you have a serious medical condition, please consult your medical practitioner immediately. Do not drive or operate heavy machinery while listening to this recording. © Stardust Vibes, 2018. All rights reserved. Any reproduction or republication of all or part of this video/audio is prohibited.

Like early explorers mapping the continents of our globe, astronomers are busy charting the spiral structure of our galaxy, the Milky Way. Using infrared images from NASA's Spitzer Space Telescope, scientists have discovered that the Milky Way's elegant spiral structure is dominated by just two arms wrapping off the ends of a central bar of stars. Previously, our galaxy was thought to possess four major arms.

The annotated artist's concept illustrates the new view of the Milky Way. The galaxy's two major arms (Scutum-Centaurus and Perseus) can be seen attached to the ends of a thick central bar, while the two now-demoted minor arms (Norma and Sagittarius) are less distinct and located between the major arms.
The major arms consist of the highest densities of both young and old stars; the minor arms are primarily filled with gas and pockets of star-forming activity.

The artist's concept also includes a new spiral arm, called the "Far-3 kiloparsec arm," discovered via a radio-telescope survey of gas in the Milky Way. This arm is shorter than the two major arms and lies along the bar of the galaxy.

Our Sun lies near a small, partial arm called the Orion Arm, or Orion Spur, located between the Sagittarius and Perseus arms.
# MilkyWay #space #Universe

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