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Astronomers Strike Gravitational Gold In Colliding Neutron Stars (npr.org)
For the first time, scientists have caught two neutron stars in the act of colliding, revealing that these strange smash-ups are the source of heavy elements such as gold and platinum. From a report: The discovery, announced today at a news conference and in scientific reports written by some 3,500 researchers, solves a long-standing mystery about the origin of these heavy elements -- which are found in everything from wedding rings to cellphones to nuclear weapons. It's also a dramatic demonstration of how astrophysics is being transformed by humanity's newfound ability to detect gravitational waves, ripples in the fabric of space-time that are created when massive objects spin around each other and finally collide. "It's so beautiful. It's so beautiful it makes me want to cry. It's the fulfillment of dozens, hundreds, thousands of people's efforts, but it's also the fulfillment of an idea suddenly becoming real," says Peter Saulson of Syracuse University, who has spent more than three decades working on the detection of gravitational waves. Albert Einstein predicted the existence of these ripples more than a century ago, but scientists didn't manage to detect them until 2015. Until now, they'd made only four such detections, and each time the distortions in space-time were caused by the collision of two black holes. That bizarre phenomenon, however, can't normally be seen by telescopes that look for light. Neutron stars, by contrast, spew out visible cosmic fireworks when they come together. These incredibly dense stars are as small as cities like New York and yet have more mass than our sun. Further reading: 'A New Rosetta Stone for Astronomy' (The Atlantic), and Gravitational Wave Astronomers Hit Mother Lode (Scientific American).
"Chance favors the prepared mind."
This is an example of that at it's purest, the culmination of years of effort by hundreds of people, all for a moment that might not have happened in their lifetimes.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
I can't seem to find the result of the collision in any of the articles. Did they merge to form a black hole or a larger neutron star?
>>>"These incredibly dense stars are as small as cities like New York and yet have more mass than our sun."
Please use standard units! How many football fields is that?
Massive gamma and x ray production if there is any mass in the vicinity at all
But no. Looks like that will been in about 4 hours. I am expecting to be disappointed. With the ESO website using terminology like, "ESO HQ Announcing Unprecedented Discovery" and "groundbreaking observations of an astronomical phenomenon that has never been witnessed before." It unusual for a scientific establishment to use wording like that. Crossing my fingers it will actually be something amazing. I imagine there will be a Slashdot headline.
http://www.eso.org/public/anno...
Brought to you by Carl's Junior.
I love reading net kooks. So fundamentally ignorant, and yet so absolutely certain of their genius.
The world's burning. Moped Jesus spotted on I50. Details at 11.
I thought gold was just created the same as everything else heavier than iron, in a supernova. So a quick google shows that colliding neutron stars would provide a new mechanism but it doesn't discount the old mechanism https://www.smithsonianmag.com...
doing the neutron dance, that is. :D
The actual news is that for the first time a collision event was detected with both gravitational waves and light simultaneously. The Atlantic article even has an image. This produced a wealth of knowledge, including how gold is created, alluded in the title.
A source, not the source. Kind of like how The Doctor from Doctor Who may be a Doctor but not the only doctor.
I thought Muse was responsible for the Neutron Star Collision. It went gold.
A source, not the source. Kind of like how The Doctor from Doctor Who may be a Doctor but not the only doctor.
I'm not even sure he even is a doctor. Where did he get his Ph.D. from? Does Gallifrey even have Ph.D. granting institutions? He's sure not a M.D.-- what's his doctorate in, exactly?
http://www.geoffreylandis.com
The Doctor is THE Doctor, the word doctor came from him, not the other way around :)
You're right that if Einstein hadn't come up with it, special relativity could have been derived from the mathematical insights provided by Hendrik Lorentz and Henri Poincaré, but they hadn't yet quite put it all together into the single elegant package Einstein did.
You're off target about pretty much everything else, though. The Michelson-Morley experiment was only the first of many, many experiments that validate special relativity-- with today's measurement technologies that can measure the speed of light directly, there is no need to go to all the trouble Michelson and Morley did to do interferometry. There isn't any way to incorporate ether into today's extensive array of experimental results other than "luminiferous ether, if it exists, is completely unobservable."
Most optical gyroscopes use fibers these days, and don't deal with the speed of light in vacuum at all, although you can do it with ring laser gyroscopes... which obey special relativity.
http://www.geoffreylandis.com
He has - or claims he has - a medical degree from the University of Glasgow.
systemd is Roko's Basilisk.
which are found in everything from wedding rings to cellphones to nuclear weapons.
No, they're found in the ground. They're taken out of the ground and put in those other things.
systemd is Roko's Basilisk.
None of this will convince the "electric universe" believers, or the moon landings conspiracy theorists, or the fucking flat-earthers.
You get real chemistry as soon as you're clever enough to construct Antonie van Leeuwenhoek's simple microscope.
The Greeks had glass BCE. And the Antikythera mechanism.
If they had managed to make a sufficiently clear glass bead, they would have soon discovered yeast, thence carbon dioxide, and soon the entire periodic table (soon enough to rewrite a thousand years of human history).
There were many potential paths to legitimate chemistry. The whole alchemy thing was a sad freak show. Call it the un-Einstein affair. Without Einstein, the geometric properties of space-time could have remained a freak show of the blind leading the blind down vaguely promising alleys for another half century.
What I find more interesting about LIGO is that we've basically got an intermittent, universe-scale GPS entirely for free.
To any alien civilization with their own LIGO observation database, we can now pretty precisely convey our galactic coordinate in space-time, just from the precise time ratios of the intervals between various observations, perhaps uniquely identified by participant mass (though time-stamps alone might be enough to uniquely resolve this, too—yay, metadata!).
It would be an interesting math exercise to image that some alien civilization broadcasts to us their own measured timestamps for a set of shared gravitational cymbal crashes (and suitable primer), from say 1000 light-years away (which means we need to wait a minimum of one thousand years to achieve the shared condition with the events we've presently measured) and then calculate how accurately we could pinpoint the location in space-time of the distant aliens (the co-linear events observed from our own near side would be of little utility, unless there passes another thousand years before we receive the alien coordinate list).
This is GPS on such a grand scale it's hard to even comprehend.
Proper ./ article should summarize as follows:
"this neutron star collision produced around 200 Earth masses of pure gold, and maybe 500 Earth masses of platinum"
who cares about the details and scientific mumbo-jumbo.
The actual significance of this discovery is in giving us the long-sought-after intermediary step before PROFIT, as follows:
[...]
3. Obtain 200 earth mass of pure gold and 500 earth masses of platinum from GW170817
4. PROFIT !!!
It's pretty heavy stuff.
With an optical telescope, you just point it at the thing in the sky you want to watch. With a radio telescope, you get a much bigger collector than an optical lens, and you also point it in the sky at the thing you want to watch. I'm not quite sure how you know exactly what you're looking at with a radio telescope, particularly if the thing you're observing is not visible optically, but I can make a guess.
But my question is, this neutron star collision was detected by the LIGO and Virgo gravitational wave interferometers, which don't even point at anything. Do they find the location of the source of the wave by comparing its arrival at different sites, then somehow computing a physical location that must be the origin? Wouldn't you need several of these devices to pinpoint that source accurately? Finally, how do they know that the g wave they observed corresponds with neutron stars colliding, and not any of a variety of other kinds of events?
I learned quite a bit about nucleosynthesis, but haven't revisited it in decades.
There are three main processes for synthesizing heavy elements. In the s-process (slow), neutrons are absorbed by heavy nuclei slowly enough that the nucleus has time to beta decay, if it is too neutron rich to be stable. The s-process happens in red giant stars, and the products can be released by stellar winds and planetary nebula formation.
In the r-process (rapid), neutrons are added very quickly to heavy nuclei, which absorb as many neutrons as they can and then, once the neutron bombardment ceases, beta decay back to stability. I don't recall whether we knew where the r-process happened when I was studying this, but this result would be r-process.
In the p-process (proton), nuclei grow by having protons added one at a time. This is presumed to happen in supernovae, and p-process nuclei are rare.
Isotopes coming from the s process will have abundances inversely proportional to their neutron cross section, because that cross section determines how quickly they move on. Also, while many isotopes can be produced by several of these processes, some can only be produced by one. My understanding is that these methods indicate that the s process is the predominant source of heavy elements. However this table (pointed out by other /. posters) contradicts my understanding, so possibly my knowledge has become outdated.
Can someone with more recent knowledge comment on how these new results can be reconciled with isotope abundances?
Quattuor res in hoc mundo sanctae sunt: libri, liberi, libertas et liberalitas.
He's a doctor of everything.
nice article, i thing this what we do
Did you just Google all this shit an Wikipedia and jot down your failed interpretation?
No, actually I did it the hard way, by earning a Ph.D. in physics.
It's not that what you are saying is wrong, it's more that you mix together correct statements with dubious statements, ignore most of modern physics experimental results, and then go on to make unorthodox and mostly-unsupported assertions. The point you should take away is that critiquing the 130-year-old Michelson-Morley experiments is mostly irrelevant; there are much better and much more recent experimental confirmations of special relativity. Yes, it is possible to come up with ether theories that also fit the same date, but in doing so the net result is that the theory ends up saying that the ether is undetectable, and the mathematical formulation is identical to special relativity.
http://www.geoffreylandis.com
Of course, to quote River Song, "The Doctor lies."
"When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes