- 3558 - KILO NOVAS - how gold was created? The universe is smashing things together, stars, blackholes and ultradense objects called neutron stars. When neutron stars smash together the collisions release a flood of elements necessary for life.
--------------------- 3558 - KILO NOVAS - how gold was created?
- Astronomers used subtle ripples in the fabric of space-time to confirm that colliding neutron stars make life as we know it possible. Including the gold ring on your finger.
-
- Just about everything has collided at one point or another in the history of the universe, so astronomers had long figured that neutron stars which are superdense objects born in the explosive deaths of large stars also smashed together.
-
- A neutron star collision would go out with a flash. It wouldn't be as bright as a typical supernova, which happens when very large stars explode. But astronomers predicted that an explosion generated from a neutron star collision would be roughly a thousand times brighter than a typical nova, so they dubbed it a “kilo nova“.
-
- Neutron stars are made of a lot of neutrons. A bunch of neutrons in a high-energy environment start to combine, transform, splinter off and do all sorts of other wild nuclear reactions.
-
- Kilonovas are responsible for producing enormous amounts of heavy elements, including gold, silver and xenon. Together with supernovas, kilonovas fill out the periodic table and generate all the elements necessary to make rocky planets ready to host living organisms.
-
- In 2017, astronomers witnessed their first kilonova. The event occurred about 140 million light-years from Earth and was first heralded by the appearance of a certain pattern of gravitational waves, or ripples in space-time, washing over Earth.
-
- These gravitational waves were detected by the “Laser Interferometer Gravitational-Wave Observatory” (LIGO) and the Virgo observatory, which immediately notified the astronomical community that they had seen the distinct ripple in space-time that could only mean that two neutron stars had collided.
-
- Less than 2 seconds later, the “Fermi Gamma-ray Space Telescope” detected a gamma-ray burst, that is a brief, bright flash of gamma-rays.
-
- A flurry of scientific interest followed, as astronomers around the world trained their telescopes, antennas and orbiting observatories at the kilonova event, scanning it in every wavelength of the electromagnetic spectrum.
-
- All told, about one-third of the entire astronomical community around the globe participated in the effort. It was perhaps the most widely described astronomical event in human history, with over 100 papers on the subject appearing within the first two months.
-
- Kilonovas had long been predicted, but with an occurrence rate of 1 every 100,000 years per galaxy, astronomers weren't really expecting to see one so soon. In comparison, supernovas occur once every few decades in each galaxy.
-
- The addition of gravitational wave signals provided an unprecedented glimpse inside the event itself. Between gravitational waves and traditional electromagnetic observations, astronomers got a more complete picture from the moment the merger began.
-
- That kilonova alone produced more than 100 Earths' worth of pure, solid precious metals, confirming that these explosions are fantastic at creating heavy elements. The gold in your wedding ring was forged from two neutron stars that collided long before the birth of the solar system.
-
- Albert Einstein's theory of general relativity predicted that gravitational waves travel at the speed of light. But astronomers have long been trying to develop extensions and modifications to general relativity, and the vast majority of those extensions and modifications predicted different speeds for gravitational waves.
-
- With that single kilonova event, the universe gave us the perfect place to test this theory. The gravitational wave signal and the gamma-ray burst signal from the kilonova arrived within 1.7 seconds of each other.
-
- That was after traveling over 140 million light-years. To arrive at Earth that close to each other over such a long journey, the gravitational waves and electromagnetic waves would have had to travel at the same speed to one part in a million billion.
-
- That single measurement was a billion times more precise than any previous observation, and thus wiped out the vast majority of modified theories of gravity. No wonder a third of astronomers worldwide found it interesting.
-
- Researchers know that stars fuse light atomic nuclei to create heavier nuclei. Elements in the universe heavier than hydrogen (but lighter than iron) are created by a process known as “stellar nucleosynthesis“: nuclear reactions that occur deep inside stars' cores.
-
- It has been a long-standing mystery as to where in the universe elements heavier than iron are synthesized. Though astrophysicists have theorized processes for how heavy elements like gold, platinum and lead are created in the cosmos, observational evidence has been scarce.
-
- After blackholes, neutron stars are the densest known objects in the universe. Each is the size of a city, with a mass greater than that of Earth's sun; a teaspoon of this dense material would therefore weigh a billion tons.
-
- Neutron stars are created after stars more massive than Earth's sun explode as supernovas, leaving behind superdense magnetized balls of spinning matter composed mainly of neutrons, neutral particles that, along with protons, are found inside atomic nuclei.
-
- Neutron stars therefore contain some of the building blocks of atomic nuclei. If these neutrons are somehow released from a neutron star, they might undergo reactions that allow them to stick together, creating elements heavier than iron.
-
- Newly formed particles will be highly unstable and will lose neutrons, radioactively decaying into lighter particles. But if the surrounding environment is dense in free neutrons, more neutrons can be captured before the nuclei will decay, so heavier and heavier elements can be formed.
-
- If a neutron star smashes into another neutron star, clumps of neutrons are blasted into space and can rapidly synthesize heavy elements like gold via a mechanism called rapid neutron capture process, or "r-process" .
-
- When astronomers confirmed the detection of the gravitational wave signal “GW170817” that emanated from the site of a gamma-ray burst in a galaxy 130 million light-years away, they realized they were looking at an intense cosmic collision called a "kilonova."
-
- This was a ripe environment for the r-process to take place. Kilonovas are powerful explosions that unleash gamma-rays and have been long theorized to occur when neutron stars collide.
-
- By comparing observations made using the Hubble Space Telescope and Gemini Observatory with theoretical models, astronomers have now confirmed that the r-process occurs in kilonovas, observing the spectroscopic fingerprint of heavy elements being created in the explosion's afterglow.
-
- With the help of the new gravitational wave signal, researchers now estimate that neutron star collisions may be responsible for the creation of most of the r-process heavy elements, like gold, found in galaxies.
-
- To paraphrase famed astronomer Carl Sagan, “while we may be made of "star stuff," the ring on your finger is made of "neutron star stuff."
-
April 25, 2022 KILO NOVAS - how gold was created? 3558
----------------------------------------------------------------------------------------
----- Comments appreciated and Pass it on to whomever is interested. ---
--- Some reviews are at: -------------- http://jdetrick.blogspot.com -----
-- email feedback, corrections, request for copies or Index of all reviews
--- to: ------ jamesdetrick@comcast.net ------ “Jim Detrick” -----------
--------------------- --- Wednesday, April 27, 2022 ---------------------------
No comments:
Post a Comment