The breakthrough image was captured by the Event Horizon telescope EHT , a network of eight radio telescopes spanning locations from Antarctica to Spain and Chile, in an effort involving more than scientists.
We have seen what we thought was unseeable. We have taken a picture of a black hole. The EHT picks up radiation emitted by particles within the disc that are heated to billions of degrees as they swirl around the black hole at close to the speed of light, before vanishing down the plughole. The dark shadow within marks the edge of the event horizon, the point of no return, beyond which no light or matter can travel fast enough to escape the inexorable gravitational pull of the black hole.
Since then, astronomers have accumulated overwhelming evidence that these cosmic sinkholes are out there, including recent detection of gravitational waves that ripple across the cosmos when pairs of them collide. But black holes are so small, dark and distant that observing them directly requires a telescope with a resolution equivalent to being able to see a bagel on the moon.
- Known Space - Wikipedia;
- Local Class Field Theory?
- A Hole in Space - Wikipedia.
- Prisoners of The Sun (The Adventures of Tintin 14).
- Challenges in Plutonium Science [Vol 1 and 2];
- Play Acoustic Guitar with ... Bob Dylan;
This was once thought to be an insurmountable challenge. When observations were launched in , the EHT had two primary targets. The second target, which yielded the image, was a supermassive black hole in the galaxy M87, into which the equivalent of 6bn suns of light and matter has disappeared. The success of the project hinged on clear skies on several continents simultaneously and exquisite coordination between the eight far-flung teams. Observations at the different sites were coordinated using atomic clocks, called hydrogen masers, accurate to within one second every million years.
And, on one night in April , everything came together. The sheer volume of data generated was also unprecedented — in one night the EHT generated enough data to fill half a tonne of hard drives. This meant waiting for half a year for the South Pole data, which could only be shipped out at the end of Antarctic winter.
The observations are already giving scientists new insights into the weird environment close to black holes, where gravity is so fierce that reality as we know it is distorted beyond recognition. At the event horizon, light is bent in a perfect loop around the black hole, meaning if you stood there you would be able to see the back of your own head. Scientists are also hoping to understand more about the origin of jets of radiation that are blasted out from the poles of some black holes at close to the speed of light, creating brilliant beacons that can be picked out across the cosmos.
The answer may be maybe not. The Event Horizon Telescope relies on a technique called interferometry. Similarly, with the EHT, the signals from all eight telescopes have to be combined and fed through a computer to turn a mountain of incomprehensible blips into a visual picture. Thanks for telling us about the problem. Return to Book Page. A Hole in Space by Larry Niven. The Perfect Crime: The invention of displacement booths produced one hell of a crime wave. If a man in, say, Hawaii could commit murder in, say, Chicago and be back in the time it would take him to visit the men's room, he would have a perfect alibi.
And the police would have a problem. But that's only one of the problems found in Larry Niven's universe, in this collection The Perfect Crime: The invention of displacement booths produced one hell of a crime wave. But that's only one of the problems found in Larry Niven's universe, in this collection of stories all about teleportation, deep space, black holes, artificial worlds and Louis Wu--our old friend from the "Known Space" cycle--Niven once again proves he's a master builder of fantastic worlds! Get A Copy. Paperback , pages.
Published April 12th by Del Rey first published June More Details Original Title. Other Editions 9. Friend Reviews. To see what your friends thought of this book, please sign up. To ask other readers questions about A Hole in Space , please sign up. Lists with This Book. Community Reviews. Showing Rating details. More filters. Sort order. Aug 15, Craig rated it really liked it. A Hole in Space was one of Niven's best early collections, with stories from several of his best-known and most popular universes.
It can be argued that Niven was more effective in those days as a short fiction writer than he was as a novelist, because he could throw his ideas out to challenge and engage the reader without bothering overmuch with complex plot or character motivation. He was always one of the best thinking-persons writers. Aug 11, Paul rated it really liked it Shelves: crime , mystery , science-fiction.
Pretty great Larry Niven short story collection, mostly focusing on the problems created by the invention and popularization of "displacement Booths" AKA teleportation as mass transit. For all you nerds out there Stories of note in this collection: RAMMER: a man who had himself cryogenically frozen wakes up to find himself in a very different future then he could ever imagine.
Shelves: short-fiction , science-fiction , stalled. First pub , Vertex. Puzzle story, and not a particularly good one. Stalled, probably headed for DNF. Not horrible, but way off his best! View 1 comment. Jun 27, Jeff rated it really liked it Shelves: read Yet another freebie from the "Y". I love their book table. This copy was the paperback, not even sure if the book is still in print. It was a simpler time. There are 10 stories in this collection. Two of them are basically essays about the economics of space travel, one from the standpoint of what to do when you have to rescue a lost expedition and one about how star ships can scale up in size including Dyson spheres and Niven's Yet another freebie from the "Y".
Tales of Known Space: The Universe of Larry Niven
Two of them are basically essays about the economics of space travel, one from the standpoint of what to do when you have to rescue a lost expedition and one about how star ships can scale up in size including Dyson spheres and Niven's own Ringworld. The others are fictions surrounding the basic theme of teleportation and the issue that arise. Well worth checking out. Aug 05, Dark-Draco rated it really liked it Shelves: science-fiction , short-story-collection. A fantastic collection of short stories - I too like the idea of displacement booths, but for the vision of wide, empty streets with no cars whizzing along them.
Probably my favourite two stories were the last two - "The Hole Man" is quite a scary thought of how just a small black hole could swallow a planet, a solar system. And "The Fourth Profession" was actually quite funny. Jan 11, Mars rated it it was amazing. A collection of short and not so short stories by Niven.
Quite a few recurring themes, but all are exceptionally well written, fun, and mildly educational although I reserve my doubts about some of his math. Also, to quote one of my friends, "heh, heh, A-hole in space". Sep 19, Paul rated it liked it Shelves: scifi , short-story-collection , read-as-paper , read-as-ebook. I first read this as a kid. I know I started reading Niven with a short story collection but I'm not sure if it was this or The Flight of the Horse.
I think it was this. When I started reading it this time around it was because a my reading had stalled and I wanted to kick-start it with something familiar, and b I had a hankering for a particular story The Fourth Profession. Which might be ways of excusing the fact that this book isn't that great but I read it anyway. I'm not sure if you were I first read this as a kid. I'm not sure if you were completely new to his work this would be a good place to start.
Unless you were into that era of SciFi as a retro thing. As with a lot of old scifi it's amusing what is still futuristic and what's old fashioned.
Black Holes: Facts, Theory & Definition | Space
A world where teleportation is real but people still type up notes on paper. A world where interstellar space travel is possible but computers take up a floor of a building. That rating is a bit misleading because it's a bit of an average, so let's do a breakdown: Rammer - a 20th century man who had his body frozen is awakened in the 22nd century in another body and trained as a spaceship pilot. Probably my favourite of the collection. It was later expanded to become A World Out of Time which is also a favourite of mine.
Reference Article: Facts about black holes.
It deals with the idea that in a world where you can "flick" long distances alibis almost become useless, in the time you take to pop to the loo you could travel somewhere and kill someone. Like a lot of Niven's stories this is about exploring what that would mean and how we might adapt, but the story itself lacks bite. This deals with the idea that teleportation would lead to "flash mobs" whenever something interesting happened cos if you can just 'flick' there why not?