Guest fountainhall Posted December 15, 2011 Share Posted December 15, 2011 I have always found particle physics all but impossible to grasp. Grasp? It’s never got near my fingertips! Even Stephen Hawking’s A Brief History of Time, supposedly an easyish read, lasted only a few pages before I gave up. Now there’s another reason to try and learn a bit more. The BBC website today has an article about the supermassive black hole at our galaxy’s centre that scientists seem to have known about for quite some time. What is new, though, is they have discovered a giant gas cloud spiraling around that hole. The cloud has an oval-shaped path and has doubled speed in the last seven years – to 2,350 kms per second. Yikes! Doesn’t a back hole gobble up everything around it? Are we, like the cloud, destined to a whirlpool-like end? Perhaps. But not in our lifetimes, thankfully. For this black hole named “Sagittarius A” is 27,000 light-years away. But it’s a big one with a mass about four million times that of our sun. For the newly-found cloud, though, the end is nearer. By mid-2013 it will be 40 billion kms (a mere stone’s throw!) from the black hole and ready to be swirled around in a raging whirlpool and then sucked right inside. Or at least half of it will; the other half being flung back out into space, we’re told According to the BBC, the cloud – . . . does not comprise enough matter to hold itself together under its own gravity, as a star might, so the cloud will begin to elongate as it meets its doom. "The idea of an astronaut close to a black hole being stretched out to resemble spaghetti is familiar from science fiction," said lead author of the study Stefan Gillessen, from Max Planck Institute for Extraterrestrial Physics in Germany. "But we can now see this happening for real to the newly discovered cloud. It is not going to survive the experience." The acceleration of the cloud's constituent material will create a shower of X-rays that will help astronomers learn more about our local black hole. http://www.bbc.co.uk/news/science-environment-16178112 So we have our local supermarket, local pub, local mall – and our local black hole. I wonder if there’s anything other than spaghetti inside? Quote Link to comment Share on other sites More sharing options...
KhorTose Posted December 15, 2011 Share Posted December 15, 2011 So we have our local supermarket, local pub, local mall Quote Link to comment Share on other sites More sharing options...
Guest thaiworthy Posted December 15, 2011 Share Posted December 15, 2011 No apologies necessary. Our very own black hole does indeed contain spaghetti and is very much like Pattaya. As my Italian father used to say, "Spaghetti without the cheese is like a kiss without the squeeze." Sometimes Pattaya can be all kisses and no squeezes. But if the sauce is good enough, mebbe you don't need the cheese. Quote Link to comment Share on other sites More sharing options...
Rogie Posted December 15, 2011 Share Posted December 15, 2011 The Beer Bar's awash with 'em. And as for the one at the centre of the MIlky Way being the mass of 4 million sun's, pa! take a look at these, if YOU DARE! The one at the core of Milky Way weighs as much as a couple of million stars, and it could swallow the sun without even noticing, the way you'd swallow a pistachio. But that's positively puny compared with the two new black holes, each about 330 million light-years away or so, just announced in the journal Nature. The smaller one, located inside a galaxy known as NGC 3842, is as massive as 9.7 billion suns, and the other, in a galaxy called NGC 4889, is more than twice as large: if you put it on a very large balance, it would take at least 21 billion stars to even things out. Another way to think about things: even the smaller of the two is nearly 30% bigger than the previous record holder, announced last winter Read more: http://www.time.com/time/health/article/0,8599,2101916,00.html#ixzz1gb8qYtwB Quote Link to comment Share on other sites More sharing options...
Guest fountainhall Posted December 15, 2011 Share Posted December 15, 2011 take a look at these, if YOU DARE! Gulp! A monster the size of 21 billion suns! At least it and its companion are 330 million light years away. I feel kinda comforted by that! Quote Link to comment Share on other sites More sharing options...
Guest Posted December 15, 2011 Share Posted December 15, 2011 I have always found particle physics all but impossible to grasp. Never mind particle physics, a grasp of basic physics is what people need to get through life. That allows people to avoid little errors like putting a 10A mcb on a 3500W shower, which means it keeps tripping out (as I suffered in a recent hotel). As for particle physics, well we did it in school & I have never needed it since. Quote Link to comment Share on other sites More sharing options...
Guest fountainhall Posted December 15, 2011 Share Posted December 15, 2011 putting a 10A mcb on a 3500W shower I didn't do even basic physics, and haven't a clue what that means! Quote Link to comment Share on other sites More sharing options...
KhorTose Posted December 15, 2011 Share Posted December 15, 2011 I didn't do even basic physics, and haven't a clue what that means! He is talking about a 10 Amp miniature circuit breaker and the impossibility of running a 3500 Watt water heater on such a small circuit breaker. the basic rule is Watts equals Amps times Volts or WAV In this case on a 220 volt circuit were you have X amount of Watts and 10 Amps, the amount of Watts you can run on this breaker is: Watts ='s 10Amps times 220 volts for the masimum of 2200 watts making it impossible to run a 3500 watt heater. To find out what you would need to run a 3500 watts heater on 220 Volts: 3500 watts ='s x Amps times 220 which works out to: 3500 divided by 220 ='s 15.91 Amps. A decent electrican would now install a 20 AMP MCB. Is this clear enough??? Quote Link to comment Share on other sites More sharing options...
Guest Posted December 16, 2011 Share Posted December 16, 2011 A decent electrican would now install a 20 AMP MCB. However, this is SE Asia, so the electricians sometimes get it wrong. Also, it seems the hotel owners obviously don't check these things before paying the electrician. Quote Link to comment Share on other sites More sharing options...
Guest fountainhall Posted December 16, 2011 Share Posted December 16, 2011 3500 watts ='s x Amps times 220 which works out to: 3500 divided by 220 ='s 15.91 Amps. i.e. precious little hot water, I'd imagine! Thanks KhorTose. I never knew all that! Quote Link to comment Share on other sites More sharing options...
kokopelli Posted December 16, 2011 Share Posted December 16, 2011 I have always found particle physics all but impossible to grasp. Even I who studied physics under Dr. Newton, can tell you that particle physics does not apply to black holes. Black holes are in the realm of Einsteinian physics; even Einstein had problems with the quantum mechanics and those crazy particles who don't know up from down or where they are or should be or when they should be. Quote Link to comment Share on other sites More sharing options...
Rogie Posted February 20, 2012 Share Posted February 20, 2012 Yikes! Doesn’t a back hole gobble up everything around it? Are we, like the cloud, destined to a whirlpool-like end? Here's another future black hole come to torment you FH! The article quoted below is badly written but recent developments in astronomy make fascinating reading. When the sun finally dies some 5 billion years from now, the end will come quietly, the conclusion of a long, uneventful life. Our star will, in a sense, go flabby, swelling first, releasing its outer layers into space and finally shrinking into the stellar corpse known as a white dwarf. Things will play out quite differently for a supermassive star like Eta Carinae, which lies 7,500 light-years from Earth. Weighing at least a hundred times as much as our sun, it will go out more like an adolescent suicide bomber, blazing through its nuclear fuel in a mere couple of million years and exploding as a supernova, a blast so violent that its flash will briefly outshine the entire Milky Way. The corpse this kind of cosmic detonation leaves behind is a black hole. For Eta Carinae, that violent end might not be long in coming, according to a report in the latest Nature. "We know it's close to the end of its life," says astronomer Armin Rest of the Space Telescope Science Institute and the lead author of the paper. "It could explode in a thousand years, or it could happen tomorrow." In astronomical terms, a thousand years might as well be tomorrow; as for a supernova blowing up literally tomorrow, well, that's almost unheard of. Read more: http://www.time.com/time/health/article/0,8599,2106904,00.html#ixzz1mx53Ufdj Quote Link to comment Share on other sites More sharing options...
Guest fountainhall Posted February 21, 2012 Share Posted February 21, 2012 Going flabby after first swelling, “releasing” and then shrinking? The image that comes to my mind is pretty clear – and it ain’t no dwarf! But the news about Eta Carinae sounds a bit serious. Does this mean we now have to start thinking about renovating all those decaying nuclear fallout shelters so they become exploding supernova shelters? Quote Link to comment Share on other sites More sharing options...
kokopelli Posted February 21, 2012 Share Posted February 21, 2012 But the news about Eta Carinae sounds a bit serious. Does this mean we now have to start thinking about renovating all those decaying nuclear fallout shelters so they become exploding supernova shelters? Never fear! Back in 1054 CE there was a recorded supernova from a star that was about the same distance as Eta Carinae 7000 light years away. It was reported as 1/4 the brightness of a full moon. The earth survived, this time. There have been a number of supernovas that have been observed since ancient times that have occurred to stars in our Milky Way Galaxy but still a rare occurence. Quote Link to comment Share on other sites More sharing options...
Rogie Posted February 21, 2012 Share Posted February 21, 2012 I just love these kind of reports. No cause for alarm though! This happened nearly four years ago and lasted just a few hours. A few hours visible with the naked eye here on earth from an object half way to the known edge of the universe. The object was 7,500,000,000 light years away yet the gamma ray burst was visible. I find that pretty amazing. Sadly I never got to see it but kept the report that came through on World Science. Here it is in its entirety. ______________________________________________________________ March 20, 2008 Courtesy NASA and World Science staff A gigantic stellar explosion detected March 19 by has shattered the record for the furthest object visible with the naked eye, scientists say—halfway across the known universe. Sadly, the show lasted only hours. But “if someone just happened to be looking at the right place at the right time, they saw the most distant object ever seen by human eyes without optical aid” on record, said Stephen Holland of NASA’s Goddard Space Flight Center in Greenbelt, Md. The afterglow of GRB 080319B was imaged by Swift's X-ray Telescope (left) and Optical/Ultra&s Telescope (right). (Credit: NASA/Swift/Stefan Immler, et al.) Detected by the agency’s Swift satellite, the explosion was a gamma ray burst, a type of blast that usually occurs when massive stars run out of their nuclear fuel. Their cores collapse to form extremely dense objects known as black holes or neutron stars. In the process they release a great burst of high-energy gamma rays and particle jets that rip through space at nearly light speed. As the jets plow into surrounding interstellar clouds, they heat the gas, often generating bright afterglows. Gamma ray bursts are believed to be the most luminous explosions in the universe, and this one “was a whopper,” said Swift principal investigator Neil Gehrels of the Goddard center. “It blows away every gamma ray burst we’ve seen so far.” Swift’s Burst Alert Telescope picked up the burst at 2:12 a.m. Eastern U.S. time and pinpointed the coordinates in the constellation Boötes, researchers said. Telescopes in space and on the ground quickly moved to catch the afterglow. The burst is named GRB 080319B, because it was the second gamma ray burst found that day. Two other Swift instruments also observed afterglows. Several ground-based telescopes saw the afterglow brighten to visual magnitudes between 5 and 6, in the scale used by astronomers. The brighter an object is, the lower its magnitude number. From a dark location in the countryside, people with normal vision can see stars slightly fainter than magnitude 6. Thus the afterglow would have been dim, but visible to the naked eye, said Holland, a member of the Swift science team. Later, the Very Large Telescope in Chile and the Hobby-Eberly Telescope in Texas measured the burst’s redshift at 0.94. A redshift is a measure of the distance to an object. A redshift of 0.94 translates into a distance of 7.5 billion light years, meaning the explosion took place 7.5 billion years ago, a time when the universe was less than half its current age and Earth had yet to form. The burst was seen occurring in the distant past because its light takes so long to reach us. “No other known object or type of explosion could be seen by the naked eye at such an immense distance,” said Holland. GRB 080319B’s optical afterglow was 2.5 million times more luminous than the most luminous supernova, or stellar explosion, ever recorded, scientists said. That would make it the most intrinsically bright object ever observed by humans. The most distant previous object that could have been seen by the naked eye is the nearby galaxy M33, a relatively short 2.9 million light-years from Earth. Analysis of GRB 080319B is just getting underway, so astronomers don’t know why this burst and its afterglow were so bright. One possibility is the burst was more energetic than others, perhaps because of the mass, spin, or magnetic field of the progenitor star or its jet, scientists said. Or perhaps it concentrated its energy in a narrow jet aimed directly at Earth. GRB 080319B was one of four bursts that Swift detected, a Swift record for one day—as it happened, the same day acclaimed science-fiction writer Arthur C. Clarke died. “Coincidentally, [his death] seems to have set the universe ablaze with gamma ray bursts,” said Swift science team member Judith Racusin of Penn State University. ___________________________________________________________________ Here's another supernova picked up last year in August: On Wednesday, August 24, using the 48 inch Palomar robotic telescope in southern California- which is designed to observe and uncover astronomical events as they happen- astronomers noticed a new star, dubbed SN 2011fe, in the relatively nearby spiral galaxy M 101 just off the handle of the Big Dipper. Located 21 million light years away, this is the closest Type 1a supernova seen in decades. a Type Ia supernova occurs when a white dwarf draws matter in from a companion star and dumps it on its surface until a runaway nuclear reaction ignites. While many such supernovae are discovered annually they tend to be much farther away at hundreds of millions or billions of light years away. http://newswatch.nationalgeographic.com/2011/08/26/night-sky-news-new-supernova-blast-brightening-fast/ Quote Link to comment Share on other sites More sharing options...
Rogie Posted August 31, 2012 Share Posted August 31, 2012 Ever wondered about that hot dog you just ate? Well, here's something to munch on! Supermassive black holes and hot galaxies in giant haul A space telescope has added to its list of spectacular finds, spotting millions of supermassive black holes and blisteringly hot, "extreme" galaxies. The finds, by US space agency Nasa's Wide-Field Infrared Survey Explorer (Wise), once lay obscured behind dust. But Wise can see in wavelengths correlated with heat, seeing for the first time some of the brightest objects in the Universe. The haul will help astronomers work out how galaxies and black holes form. It is known that most large galaxies host black holes at their centres, sometimes feeding on nearby gas, dust and stars and sometimes spraying out enough energy to halt star formation altogether. How the two evolve together has remained a mystery, and the Wise data are already yielding some surprises. Wise gives astronomers what is currently a unique view on the cosmos, looking at wavelengths of light far beyond those we can see but giving information that we cannot get from wavelengths we can. http://www.bbc.co.uk/news/science-environment-19421453 Quote Link to comment Share on other sites More sharing options...
Bob Posted August 31, 2012 Share Posted August 31, 2012 My head starts to hurt just contemplating what a "light year" is. It seems it's both a unit of time (the time it takes light to travel in a vacuum in one of our years) and a unit of distance (the distance light travels in one of our years - or about 5.8 trillion miles). So, the sighting that Khun FH noted in the original post actually occurred a long, long (etc) way from here and 27,500 years ago. Old news! (Khun Khortose was just a wee tot licking an electrical panel when that happened!) Quote Link to comment Share on other sites More sharing options...
ChristianPFC Posted August 31, 2012 Share Posted August 31, 2012 A light year is only a unit of distance. To make your confusion complete, a parsec is the distance from which the distance between Sun and Earth appear under an angle of one second. http://en.wikipedia.org/wiki/Parsec Quote Link to comment Share on other sites More sharing options...
Guest fountainhall Posted August 31, 2012 Share Posted August 31, 2012 Is that Latvian you are speaking, Christian? I don't understand a word Quote Link to comment Share on other sites More sharing options...
Rogie Posted August 31, 2012 Share Posted August 31, 2012 Luckily I came across this Latvian translator Calculating the value of a parsec In the diagram above (not to scale), S represents the Sun, and E the Earth at one point in its orbit. Thus the distance ES is one astronomical unit (AU). The angle SDE is one arcsecond (1/3600 of a degree) so by definition D is a point in space at a distance of one parsec from the Sun. By trigonometry, the distance SD is Using small-angle approximation, One AU ≈ 149597870700 metres, so 1 parsec ≈ 3.085678×1016 m ≈ 3.261564 ly. A corollary is that 1 parsec is also the distance from which a disc with a diameter of 1 AU must be viewed for it to have an angular diameter of 1 arcsecond (by placing the observer at D and a diameter of the disc on ES). Source: same wiki link as in post #18 Quote Link to comment Share on other sites More sharing options...
Bob Posted August 31, 2012 Share Posted August 31, 2012 A light year is only a unit of distance. Generally, yes; however, the definition of the term itself ties itself to time (a light year being the distance that light travels in a perfect vacuum in one julian year). We see a star located 10 light years from us but, at the moment we see it, what we're really seeing is how that star appeared/existed 10 years ago (it took the light from that star 10 years to get here). Quote Link to comment Share on other sites More sharing options...
Guest fountainhall Posted September 1, 2012 Share Posted September 1, 2012 One AU ≈ 149597870700 metres, so 1 parsec ≈ 3.085678×1016 m ≈ 3.261564 ly. Jeez, we're now talking Martian!! Quote Link to comment Share on other sites More sharing options...
KhorTose Posted September 1, 2012 Share Posted September 1, 2012 The real black hole in the universe is in the integrity of the Thai police. I just got stopped for making a left hand turn from one one way street into another one way street against a red light. The fine 200 baht, which I had to get off my bike in order to place the money in the compartment under my seat, where the cop proceeded to collect it. Barf. Quote Link to comment Share on other sites More sharing options...
Rogie Posted September 1, 2012 Share Posted September 1, 2012 I hope you understand the gravity of the situation KT. Not to make light of the situation, it seems one hundred baht notes are irresistably drawn to the pocket of the police officer. Just as in real life (i.e police lurking in the back streets of Chiang Mai) there are far more black holes in the universe than we ever thought possible. Quote Link to comment Share on other sites More sharing options...
