About That Monstrous Black Hole We're All Orbiting (theatlantic.com) 101
Astronomers on Wednesday reported new telescope observations of the environment around the Milky Way's supermassive black hole, named Sagittarius A*, pronounced "a-star," and they transformed the data into a lively animation. From a report: The video is positively ghostly. Clumps of gas swirl around the black hole, traveling at about 30 percent of the speed of light. Astronomers collected the data for the visualization using an instrument on the European Southern Observatory's Very Large Telescope, located in the deserts of northern Chile. The instrument, appropriately named GRAVITY, detected flares of infrared radiation coming from the disk surrounding Sagittarius A*. The researchers believe the bursts originated very close to the black hole, in an incredibly tumultuous region known as the innermost stable orbit. Here, cosmic material is slung around violently, but it remains far away enough that it can circle the black hole safely without getting sucked into the darkness.
If the thought of orbiting a monstrous, star-gobbling black hole spooks you, don't worry. Earth, located about two-thirds out from the center of the Milky Way, is at a very safe distance. The planet is in no danger of being consumed and wiped off the face of the universe. But, like everything else in the galaxy, it has long been subject to the black hole's whims. When black holes belch radiation out into space, the outflow can heat surrounding gas so much that it prevents it from cooling. If cosmic dust can't cool, it can't condense to form individual, brand-new stars, including ones like our sun. Scientists suspect that the fates of galaxies -- whether they produce new stars or stop altogether -- rests with the supermassive black holes at their centers.
If the thought of orbiting a monstrous, star-gobbling black hole spooks you, don't worry. Earth, located about two-thirds out from the center of the Milky Way, is at a very safe distance. The planet is in no danger of being consumed and wiped off the face of the universe. But, like everything else in the galaxy, it has long been subject to the black hole's whims. When black holes belch radiation out into space, the outflow can heat surrounding gas so much that it prevents it from cooling. If cosmic dust can't cool, it can't condense to form individual, brand-new stars, including ones like our sun. Scientists suspect that the fates of galaxies -- whether they produce new stars or stop altogether -- rests with the supermassive black holes at their centers.
We're all going to dieeeeee!!!! (Score:2)
Well, um, sometime after the sun goes nova.....
What, first post?
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Well, um, sometime after the sun goes nova.....
What, first post?
More like "last post"... ;)
Re:We're all going to dieeeeee!!!! (Score:5, Interesting)
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All the fun astronomical stuff will take place after we die.
I hope so! The alternative is it happens when we die.
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More like about eight minutes before we die.
The lucky ones, anyway...
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All of it will be a slow process within a human lifetime. Even during the expansion into a red giant if humans were around from their birth to their death any single human wouldn't notice much of a change in the sun during their own lifetime.
Re:We're all going to dieeeeee!!!! (Score:4, Informative)
Even before the sun's red giant phase it will have doubled in luminosity. Assuming no feedback effects, that would increase Earth's equilibrium temperature by 19% on an absolute temperature scale. So if you assume that feedback mechanisms remain the same, you're talking at least 50 degrees celsius temperature increase.
Of course, that's far too simplistic of an approach to take; feedback levels will change, and the details of that are a complex modeling task. Runaway greenhouse effects are quite possible (such as: loss of crustal water = reduce crustal viscosity = reduced / eliminated large-scale plate tectonics = Venus-like geology).
Of course, the biggest question is whether any sort of sentient life would exist in the system at that point in time. If so, it would likely be so far advanced (billions of years of technological development) that building an orbital solar reflector would be a laughably trivial task, and even relocating the planet might be within their reach. The ultimate achievement would be if they were to develop technology to siphon off matter from the sun over billions of years, ultimately reducing its mass to under 0,3Msol. Then it would not only burn slower, but also be fully convective - greatly extending its lifespan. Very low mass main sequence stars can potentially burn for trillions of years.
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You're forgetting that the sun will expand in radius as it goes red giant. The Earth will be inside it....briefly.
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Through what mechanism? Reverse gravity?
The only way I can think of for an expanding sun to push the planetary orbits out would be a shock wave, which isn't so much going to push out your orbit, as simply scatter things in random directions that may or may not end up in stable orbits -- in fact, they may or may not still be in one piece.
The orbits aren't simply going to get bigger with the sun, because any force act
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What kind of 'definitive answer' to an incredibly stupid idea not founded in physics would you require?
According to this article [space.com], your opinion may not be the definitive answer.
In approximately 5 billion years, the sun will begin the helium-burning process, turning into a red giant star. When it expands, its outer layers will consume Mercury and Venus, and reach Earth. Scientists are still debating whether or not our planet will be engulfed, or whether it will orbit dangerously close to the dimmer star. Either way, life as we know it on Earth will cease to exist.
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Some have argued with me that an expanding sun would just push the planetary orbits outward
FTFY — You took my comment out of context. I'm a fan of the earth shall burn, baby, burn! But I'm open minded enough to consider counter arguments.
Stick to unboxing Chinese plastic toys.
???
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Look at all the formatting. The bizarre reference to unboxing toys.
You're a sad cunt. Get a life.
You're actually right, but that is beside the point.
Re:We're all going to dieeeeee!!!! (Score:4, Informative)
Pretty sure that's wrong.
Orbits only depend on mass, not density. So assuming the actual mass of the Sun doesn't change when it goes supernova then our orbit won't change.
Likewise, if the Sun were replaced tomorrow with a black hole with the same mass, it would be the size of a small town but none of the planets' orbits would change. Although we would freeze to death.
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1) The sun will not go supernova :)
2) The sun actually does lose significant mass in its red giant phase
3) There's a wide variety of stellar processes that affect orbits of objects around them (although the larger the body, the less effect these processes have)
Size of a small town? (Score:3)
the size of a small town
Black holes continue to be described as singularities with zero volume.
Perhaps you mean that the volume enclosed by the event horizon is the size of a small town?
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Correct on both counts.
While the mass is indeed concentrated at the singularity, the event horizon is commonly used to define the boundary, and thus the size, of a black hole.
Re: We're all going to dieeeeee!!!! (Score:2)
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As history proves, technological development is not always forward (ie: Dark Ages, or if you're into sci-fi, after the empire falls in the Foundation Series), so even i
Re:We're all going to dieeeeee!!!! (Score:4, Informative)
Surprisingly enough, it doesn't really matter what you siphon off. In a star the mass of our sun, there's relatively little inflow of new fuel into the core. Smaller stars are fully convective, in that everything can cycle through the core. So just by simply "lightening" the star by any means, down to a red dwarf (note: not a brown dwarf!), you let all of that new fuel get in. Also, the higher mass of the sun increases the reaction rate in the core, so reducing the mass slows that down significantly. And red dwarfs are strictly hydrogen-burning; there's never a helium flash, no triple alpha process.
Red dwarfs never turn into giants. Instead, they're predicted to evolve into blue dwarfs. Although since it takes orders of magnitude longer than the age of the universe for this to happen, there are no blue dwarfs in the universe yet to observe!
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The size of the Galaxy is so big, that all action is relatively slow, in terms of observable differences.
Our lifespan we only get to observe the earth rotate around the sun about a hundred times.
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Not to nitpick...
Okay, to nitpick - "revolve", not "rotate"....
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True. Still, Betelgeuse might explode in our lifetimes, so there's that to look forward to.
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All the fun astronomical stuff will take place after we die.
Simpler than that. When you die the simulation stops. That's it.
a-star? (Score:2)
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Is that kind of like gym being spelled with a j?
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The pronunciation [pronouncekiwi.com] of a related term Gimbal Lock [wikipedia.org] depends if you are English or US. :-)
i.e.
* Gim
* Jim
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Brits come to yellowstone looking to see old people spray water into the sky.
Kinky, but is the national health really that bad?
Re:a-star? (Score:5, Interesting)
Fun fact: Sgr A* got its "star" postfix based on a nerdy joke: in atomic physics, excited states are denoted with asterisks, and Robert Brown found the signal coming from it "exciting" ;)
Re:a-star? (Score:5, Insightful)
In a language where sleigh and sleight sound nothing alike, but slate and eight rhyme, I think pronunciation rules can safely be disregarded as highly illogical.
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Yeah, the damned "great vowel shift" ...
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Another fun fact: A* is not a star.
I hate this language.
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Folks, it's insane to think that this Universe is governed almost solely by one, solely attractive, extremely weak force called "gravity". There has got to be more to it than that.
Last time I checked, which was about 3 seconds ago, modern physics defines 4 fundamental forces of nature that the universe is governed by: "Fundamental interaction" [wikipedia.org] And there are active efforts in experimental and theoretical physics to define a Fifth force [wikipedia.org]. So there is all that going on above and beyond just gravity running the big show.
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It's named GRAVITY? (Score:3)
What an amazing coincidence! I bet that doesn't happen often!
Re: It's the TRUMP Star! (Score:1)
Then more stuff should be coming out of it than in.
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um: "... and they transformed the data into a lively animation. "
Read much?
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Re:You notice that the Puppeteers already left. (Score:4)
Description of image? (Score:2)
The images and videos linked from the summary are denoted as simulations.
Anyone know what the real data look like? Or if the organge-vs-blue whisps mean anything?
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Oh please, not that guy's bullshit again.
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This is why time seems to go faster as you get old (Score:5, Interesting)
Its like a big drain the closer you get to the drain, the faster you go. And black hole drains is what causes time to exist.
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Lay off the weed. Realistic theories [scientificamerican.com]:
1. We gauge time by memorable events.
As William James hypothesized, we may be measuring past intervals of time by the number of events that can be recalled in that period. Imagine a 40-something mom experiencing the repetitive, stressful daily grind work and family life. The abundant memories of her high school years (homecoming football games, prom, first car, first kiss, graduation) may, compared to now, seem like much longer than the mere four years that they were.
2. The amount of time passed relative to one's age varies.
For a 5-year-old, one year is 20% of their entire life. For a 50-year-old, however, one year is only 2% of their life. This "ratio theory," proposed by Janet in 1877, suggests that we are constantly comparing time intervals with the total amount of time we've already lived.
3. Our biological clock slows as we age.
With aging may come the slowing of some sort of internal pacemaker. Relative to the unstoppable clocks and calendars, external time suddenly appears to pass more quickly.
4. As we age, we pay less attention to time.
When you're a kid on December 1, you're faithfully counting down the days until Santa brings your favorite Hot Wheels down the chimney. When you're an adult on December 1, you're a little more focused on work, bills, family life, scheduling, deadlines, travel plans, Christmas shopping, and all of that other boring adult stuff. The more attention one focuses on tasks such as these, the less one will notice the passage of time.
5. Stress, stress, and more stress.
As concluded by Wittmann and Lehnhoff (and replicated by Friedman and Janssen), the feeling that there is not enough time to get things done may be reinterpreted as the feeling that time is passing too quickly. Even older individuals (who are, more often than not, retired from work) may continue to feel similarly due to physical handicaps or diminished cognitive ability.
What's in a name...? (Score:4, Funny)
Wouldn't it more accurately be described as an A-hole?
Event Horizon Telescope results...? (Score:2)
When do we get results from the EHT? https://en.wikipedia.org/wiki/... [wikipedia.org]
I thought that's what this article was gonna be about, I'm so anxious to hear about those results.
Feynman loses it ... from beyond the grave (Score:2)
And the text is positively ghastly.
What do we have here?
* First, black holes radiate, almost like supernovae.
* Second, radiation is a flow, not a flux.
* Third, hot gas is naturally self-insulating.
Look, ma, no spectral emission envelope!
The flow/flux distinction is something a principled science writer would handle with thick, protective gloves.
Anyone
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We're also not orbiting Sag. A*, it's just in the center of all the mass we *are* orbiting. The Milky Way outmasses it a few hundred thousand times over, if it disappeared it'd only affect the closest stars in the core. It also doesn't have anything like the claimed effect on star formation. Perhaps they did in the early universe when they were surrounded by huge disks of accreting gas that outshone the rest of their galaxies, but not today.
Praise the Idiot God! (Score:2)
All Hail Azathoth! The Primordial Chaos that gave Birth to All and shall Devour All!