Category Archives: Astrology

Frame and Time Dragging Stars?

One of the predictions of Einstein’s general theory of relativity is that any spinning body drags the very fabric of space-time in its vicinity around with it. This is known as “frame-dragging”.

In everyday life, frame-dragging is both undetectable and inconsequential, as the effect is so ridiculously tiny. Detecting the frame-dragging caused by the entire Earth’s spin requires satellites such as the US$750 million Gravity Probe B, and the detection of angular changes in gyroscopes equivalent to just one degree every 100,000 years or so.

Luckily for us, the Universe contains many naturally occurring gravitational laboratories where physicists can observe Einstein’s predictions at work in exquisite detail.

Our team’s research, published today in Science, reveals evidence of frame-dragging on a much more noticeable scale, using a radio telescope and a unique pair of compact stars whizzing around each other at dizzying speeds.

The motion of these stars would have perplexed astronomers in Newton’s time, as they clearly move in a warped space-time, and require Einstein’s general theory of relativity to explain their trajectories.

An illustration of frame dragging. (Mark Myers/OzGrav ARC Centre of Excellence)

General relativity is the foundation of modern gravitational theory. It explains the precise motion of the stars, planets and satellites, and even the flow of time. One of its lesser-known predictions is that spinning bodies drag space-time around with them. The faster an object spins and the more massive it is, the more powerful the drag.

One type of object for which this is very relevant is called a white dwarf. These are the leftover cores from dead stars that were once several times the mass of our Sun, but have since exhausted their hydrogen fuel.

What remains is similar in size to Earth but hundreds of thousands of times more massive. White dwarfs can also spin very quickly, rotating every minute or two, rather than every 24 hours like Earth does.

The frame-dragging caused by such a white dwarf would be roughly 100 million times as powerful as Earth’s.

That is all well and good, but we can’t fly to a white dwarf and launch satellites around it. Fortunately, however, nature is kind to astronomers and has its own way of letting us observe them, via orbiting stars called pulsars.

Dragging the Space-time Continuum

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Twenty years ago, CSIRO’s Parkes radio telescope discovered a unique stellar pair consisting of a white dwarf (about the size of Earth but about 300,000 times heavier) and a radio pulsar (just the size of a city but 400,000 times heavier).

Compared with white dwarfs, pulsars are in another league altogether. They are made not of conventional atoms, but of neutrons packed tightly together, making them incredibly dense. What’s more, the pulsar in our study spins 150 times every minute.

Read the full article at ScienceAlert

13 full moons, 2 supermoons & Blue moon to be expected in 2020

Sky watchers may have gotten a little spoiled in 2019, with three consecutive “supermoons” appearing during the first three months of the year. Will 2020 be as good?

Astronomy experts say two supermoons will be shining in the sky this year, and one month — October — will have two full moons, making the second a “blue moon” that will be glowing on Halloween. How’s that for an eerie treat?

Although blue moons occur once every two or three years, they are even more rare on Halloween, says AccuWeather meteorologist Brian Lada. “After the blue moon on Oct. 31, 2020, trick-or-treaters will need to wait until 2039 to see the next blue moon on Halloween,” he noted.

Supermoons coming in 2020

Pixabay

Experts say two supermoons and one blue moon will be shining in the sky in 2020.

What is a supermoon?

Supermoons are moons that become full when their orbits are closer than average to the Earth — making them appear to be slightly bigger and as much as 30% brighter than ordinary full moons.

Although the precise definition varies in the astronomy world — and some experts say the average star gazer won’t notice the size and brightness difference — most say a supermoon is a moon that tracks less than 223,000 miles from the Earth during its full phase. (Some say any full moon that is 226,000 miles or closer to the Earth can be classified as a supermoon, and others set the cutoff at the precise distance of 223,694 miles.)

Regardless of the exact definition, astronomy websites seem to agree that 2020 will feature at least two supermoons — one on March 9 and another on April 7. Worth marking down on your calendar: Space.com says the April full moon will be the biggest of the year, because it will be the closest one to our planet.

Supermoons coming in 2020

Courtesy of Teri Abramson

Experts say two supermoons and one blue moon will be shining in the sky in 2020. Pictured is a supermoon that was rising above houses in Ocean County in 2016.

Dates of each full moon in 2020

In case you want to do some sky watching or photo snapping, here’s a list of the dates and times of each full moon in 2020, along with their most common nicknames. (Thanks to the Farmers’ Almanac, the Old Farmer’s Almanac and TimeAndDate.com for the details.)

Mysterious Astrological Tool Solved?

Though it it seemed to be just a corroded lump of some sort when it was found in a shipwreck off the coast of Greece near Antikythera in 1900, in 1902 archaeologist Valerios Stais, looking at the gear embedded in it, guessed that what we now call the “Antikythera mechanism” was some kind of astronomy-based clock. He was in the minority—most agreed that something so sophisticated must have entered the wreck long after its other 2,000-year-old artifacts. Nothing like it was believed to have existed until 1,500 years later.

Image source: Louisa Gouliamaki/Stringer

In 1951, British historian Derek J. de Solla Price began studying the find, and by 1974 he had worked out that it was, in fact, a device from 150 to 100 BC Greece. He realized it used meshing bronze gears connected to a crank to move hands on the device’s face in accordance with the Metonic cycle, the 235-month pattern that ancient astronomers used to predict eclipses.

By 2009, modern imaging technology had identified all 30 of the Antikythera mechanism’s gears, and a virtual model of it was released.

Nature Documentaries

Understanding how the pieces fit goes together confirmed that the Antikythera mechanism was capable of predicting the positions of the planets with which the Greeks were familiar—Mercury, Venus, Mars, Jupiter and Saturn—as well as the sun and moon, and eclipses. It even has a black and white stone that turns to show the phases of the moon. Andrew Carol, an engineer from Apple, built a (much bigger) working model of the device using Legos to demonstrate its operation.

John Pavlus

In June of 2016, an international team of experts revealed new information derived from tiny inscriptions on the devices parts in ancient Greek that had been too tiny to read—some of its characters are just 1/20th of an inch wide—until cutting-edge imaging technology allowed it to be more clearly seen. They’ve now read about 35,00 characters explaining the device.

The writing verifies the Antikythera mechanism’s capabilities, with a couple of new wrinkles added: The text refers to upcoming eclipses by color, which may mean they were viewed as having some kind of oracular meaning. Second, it appears the device was built by more than one person on the island of Rhodes, and that it probably wasn’t the only one of its kind. The ancient Greeks were apparently even further ahead in their astronomical understanding and mechanical know-how than we’d imagined.

Read the full article at BIGTHINK

Gamma Ray Burst Faster Than Light?

Faster-Than-Light Speeds Could Be Why Gamma-Ray Bursts Seem to Go Backwards in Time

Time, as far as we know, moves only in one direction. But last year, researchers found events in some gamma-ray burst pulses that seemed to repeat themselves as though they were going backwards in time.

Now, new research suggests a potential answer for what might be causing this time reversibility effect. If waves within the relativistic jets that produce gamma-ray bursts travel faster than light – at ‘superluminal’ speeds – one of the effects could be time reversibility.

Such speeding waves could actually be possible. We know that when light is travelling through a medium (such as gas or plasma), its phase velocity is slightly slower than c – the speed of light in a vacuum, and, as far as we know, the ultimate speed limit of the Universe.

Therefore, a wave could travel through a gamma-ray burst jet at superluminal speeds without breaking relativity. But to understand this, we need to back up a little to look at the source of those jets.

Gamma-ray bursts are the most energetic explosions in the Universe. They can last from a few milliseconds to several hours, they’re extraordinarily bright, and we don’t yet have a comprehensive list of what causes them.

We know from the 2017 observations of colliding neutron stars that these smash-ups can create gamma-ray bursts. Astronomers also think such bursts are produced when a massive, rapidly spinning star collapses into a black hole, violently ejecting material into the surrounding space in a colossal hypernova.

That black hole is then surrounded by a cloud of accretion material around its equator; if it’s rotating quickly enough, the fallback of the initially exploded material will result in relativistic jets shooting from the polar regions, blasting through the outer envelope of the progenitor star before producing gamma-ray bursts.

Now, back to those waves travelling faster than light.

We know that, when travelling through a medium, particles can move faster than light does. This phenomenon is responsible for the famous Cherenkov radiation, often seen as a distinctive blue glow. That glow – a ‘luminal boom’ – is produced when charged particles such as electrons move faster through water than the phase velocity of light.

Astrophysicists Jon Hakkila of the College of Charleston and Robert Nemiroff of the Michigan Technological University believe that this same effect can be observed in gamma-ray burst jets, and have conducted mathematical modelling to demonstrate how.

“In this model an impactor wave in an expanding gamma-ray burst jet accelerates from subluminal to superluminal velocities, or decelerates from superluminal to subluminal velocities,” they write in their paper.

“The impactor wave interacts with the surrounding medium to produce Cherenkov and/or other collisional radiation when travelling faster than the speed of light in this medium, and other mechanisms (such as thermalised Compton or synchrotron shock radiation) when travelling slower than the speed of light.

“These transitions create both a time-forward and a time-reversed set of [gamma-ray burst] light curve features through the process of relativistic image doubling.”

Such relativistic image doubling is thought to occur in Cherenkov detectors. When a charged particle travelling at near light-speed enters water, it moves faster than the Cherenkov radiation it produces, and therefore can hypothetically appear to be in two places at once: one image appearing to move forward in time and the other appearing to move backwards.

Read the full article at – ScienceAlert

Hand Bag or Earth Model ?

A Representation of the Cosmos?

The handbag image is so called because it looks very similar to the modern-day purse. The objects “typically feature a rounded handle-like top and a rectangular bottom, and may include varying degrees of additional details of texture or pattern” (Scranton, 2016). The images sometimes appear as stand-alone objects; sometimes they are depicted in the hand of a person, god, or mythical being in a manner similar to how one would hold a basket.

One possible theory for the proliferation of this image is its simple and straightforward representation of the cosmos. The semi-circle of the image (what would appear to be the bag’s strap) represents the hemisphere of the sky. Meanwhile, the solid square base represents the earth. “In ancient cultures from Africa to India to China, the figure of a circle was associated symbolically with concepts of spirituality or non-materiality, while that of a square was often associated with concepts of the Earth and of materiality” (Scranton, 2016). Thus, the image is used to symbolize the (re)unification of the earth and sky, of the material and the non-material elements of existence.

Olmec Monument 19, from La Venta, Tabasco, shows a man holding the handbag in his hand.

Olmec Monument 19, from La Venta, Tabasco, shows a man holding the handbag in his hand. ( Xuan Che )

Another instance of ancient handbag imagery can be found in faraway New Zealand. A Maori myth tells of a hero who once ascended to the home of the gods and returned to earth carrying three baskets full of wisdom. Thus, much like the Göbekli Tepe handbags, the Maori handbags symbolize worship and gratitude for divinely inspired knowledge.

Finally, in ancient Egyptian hieroglyphs, the handbag-like image can be seen. This time serving as a home for the gods and goddesses, with the purse straps being the domed poles of the portable tent and the square bottom being the cloth or animal skins laid across the poles. This structure is quite similar to the Native American teepee or the central Asian yurt.

Read the full article at Ancient Origins 

Three Potentially Habitable Planets

The search for potentially life-bearing exoplanets got a hefty boost this Monday, with the discovery of three Earth-sized worlds orbiting an ultracool dwarf star only 39 light years distant from our own solar system. The planets, described today in Nature, are such close cosmic neighbors that astronomers expect to root out precise details about their masses, atmospheres, chemical makeup, and thermal structure—as well as their potential habitability—with future observations.

“[With] the measurement of the masses, we should have enough information to constrain the surface conditions, notable to assess the existence of liquid water,” Michaël Gillon, astronomer at the Université de Liège and lead author of the new research, told me via email.

“The most exciting part is, of course, that these observations could also reveal chemical disequilibria originating from biological activity,” he continued.

In other words, astronomers hope to detect “biomarkers” such as oxygen, ozone, methane, or other substances that might have been produced by extraterrestrial life. While many of these markers can also be produced by non-biological processes, these three alien worlds are close enough to be studied with much greater scrutiny than most exoplanets, so it will be easier to pick up finer details about their habitability.

“In such a case, by comparing carefully all the possible scenarios involving abiotic and biological origins to the found disequilibria, a firm (and maybe positive!) conclusion about the presence of life at the surface could be obtained,” Gillon said.

Gillon and his colleagues discovered this tantalizing triplet of planets using the TRansiting Planets and PlanetesImals Small Telescope (TRAPPIST) facility in Chile, which is delightfully named for Belgian Trappist beer. These “red worlds” orbit a tiny star called TRAPPIST-1, roughly the size of Jupiter, which is classed as an “ultracool” dwarf because it has an effective temperature below 2,700 Kelvin (for comparison, the Sun’s effective temperature is 5,772 Kelvin).

Comparison of the Sun against TRAPPIST-1. Image: ESO

The two innermost planets, TRAPPIST-1b and TRAPPIST-1c, orbit the star every 1.51 days and 2.42 days, which results in them receiving about four times and two times as much solar radiation as Earth, respectively. This puts them a little too close to their host star to be considered in the habitable “Goldilocks” zone, but that doesn’t preclude the possibility that localized life might flourish on them in certain regions (more on that later).

The third planet, TRAPPIST-1d, is either within or just beyond the habitable zone, though its exact orbital period is still unclear. Based on size measurements made as the planets transited in front of their star, the three planets are no more than twice as massive as Earth, at the most.

But though they are comparable in size to our own world, these planets offer a drastically different environment for any speculative lifeforms on them. For starters, all three planets occupy such tight orbits that they are likely to be tidally locked to TRAPPIST-1, much like the Moon is to Earth, which means that only one side of each planet faces its stellar host.

Short feature on the TRAPPIST-1 discovery. Video: European Southern Observatory (ESO)/YouTube

This is a crucial factor to consider when evaluating a planetary body as a potentially life-bearing world. “The problem for habitability is that one face could be super-hot and the other super-cold, so cold that the atmosphere could freeze and collapse,” Gillon explained.

On the other hand, tidal locking might also be “a huge advantage for life,” he added. It’s possible, for instance, that eastbound winds stirred up on the daytime face of these planets create mild conditions along their western regions. “The western terminator could be colder than the dayside [face], enough to have conditions suitable for liquid water, and maybe life, even for a planet that is slightly [too close in] to be in the habitable zone.”

The only way to find out for sure is to continue studying the TRAPPIST-1 system with even more powerful and versatile telescopes, like the upcoming James Webb Space Telescope or European Extremely Large Telescope. To get the word out, Gillon and his colleagues have just launched a new website to keep the public up to date and engaged on TRAPPIST’s ongoing exoplanetary discoveries.

According to the team, ultracool dwarf star systems like TRAPPIST-1 make up about 15 percent of the stars in the vicinity of our solar system, so they are a particularly promising population to sift through in the search for proximate Earth analogs. Given that many of the most famous “Earth-like” exoplanets discovered so far are typically hundreds—or even thousands—of light year away, it’s heartening to find out that there are some premium candidates cooling their heels in our own backyard.

Source – MotherBoard 

The 9th Planet ?

Earlier this year, Mike Brown—an astronomer at Caltech who is famous for his role in the (somewhat controversial) planetary demotion of Pluto—offered, seemingly by way of atonement, evidence for the existence of a large planet in the outer Solar System.

But this distant world would be no pipsqueak, like the other icy, planetary embryos that we’ve discovered in the Kuiper Belt.

In fact, Brown and his team calculated a mass for the object of approximately 10 times the Earth’s, suggesting that it was the incipient core of a giant planet (like Jupiter or Saturn) that was jostled in the early phases of the Solar System’s formation, and rudely ejected into an astonishing 149 billion-kilometer (92 billion-mile) orbit, or nearly 75 times more distant than Pluto.

That means the hypothetical planet’s “year” can last anywhere from 10,000-20,000 terrestrial years.

Now, the evidence for the existence of such an object is indirect—specifically, the effect it seems to be having on neighboring outer Solar System bodies, called Kuiper Belt Objects (KBOs). Six of these objects had been detected with wildly eccentric orbits, including the large planetoid Sedna, with an orbital period of 11,000 years.

Image of a slide showing the orbits of the KBOs suspected of betraying the presence of a Planet Nine.  The orbit of the newly discovered, seventh KBO is the largest (“uo3L91”).  Credit: OSSOS via Mike Brown’s Twitter feed.

PLANET X, NEMESIS, AND ALL THE REST

A team of astronomers using the Canada-France-Hawaii Telescope on the Outer Solar System Origins Survey (OSSOS) have now detected a seventh such object, called “uo3L91.”

“Hey Planet Nine fans, a new eccentric KBO was discovered. And it is exactly where Planet Nine says it should be,” Mike Brown tweeted. Furthermore, he says, the new object “takes the probability of this being a statistical fluke down to ~.001% or so.”

Whether this hypothetical, 10 Earth-mass planet is the famed “Nemesis” object, said to be responsible for cometary influxes that cause mass extinctions on Earth, remains to be seen (though astronomers are, understandably, skeptical); but with the detection of uo3L91, the case for something massive lurking in the outer Solar System, and affecting the orbits of distant planetoids, just got a little bit stronger.

But we’ll have to wait and see. Perhaps more such detections will let us nail down the giant planet’s orbital path; maybe then we’ll be able to snap a picture of it with some next-gen Earth-based telescope.

Till then, keep your eyes peeled for more eccentric KBOs.

Source – Futurism