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Quantum physics requires imaginary numbers to explain reality

Theories based only on real numbers fail to explain the results of two new experiments

Imaginary numbers might seem like unicorns and goblins — interesting but irrelevant to reality.

But for describing matter at its roots, imaginary numbers turn out to be essential. They seem to be woven into the fabric of quantum mechanics, the math describing the realm of molecules, atoms and subatomic particles.

A theory obeying the rules of quantum physics needs imaginary numbers to describe the real world, two new experiments suggest.

Imaginary numbers result from taking the square root of a negative number. They often pop up in equations as a mathematical tool to make calculations easier.

But everything we can actually measure about the world is described by real numbers, the normal, nonimaginary figures we’re used to (SN: 5/8/18).

That’s true in quantum physics too. Although imaginary numbers appear in the inner workings of the theory, all possible measurements generate real numbers.

Quantum theory’s prominent use of complex numbers — sums of imaginary and real numbers — was disconcerting to its founders, including physicist Erwin Schrödinger.

“From the early days of quantum theory, complex numbers were treated more as a mathematical convenience than a fundamental building block,” says physicist Jingyun Fan of the Southern University of Science and Technology in Shenzhen, China.

Some physicists have attempted to build quantum theory using real numbers only, avoiding the imaginary realm with versions called “real quantum mechanics.”

But without an experimental test of such theories, the question remained whether imaginary numbers were truly necessary in quantum physics, or just a useful computational tool.

A type of experiment known as a Bell test resolved a different quantum quandary, proving that quantum mechanics really requires strange quantum linkages between particles called entanglement (SN: 8/28/15).

“We started thinking about whether an experiment of this sort could also refute real quantum mechanics,” says theoretical physicist Miguel Navascués of the Institute for Quantum Optics and Quantum Information Vienna.

He and colleagues laid out a plan for an experiment in a paper posted online at arXiv.org in January 2021 and published December 15 in Nature.

In this plan, researchers would send pairs of entangled particles from two different sources to three different people, named according to conventional physics lingo as Alice, Bob and Charlie.

Alice receives one particle, and can measure it using various settings that she chooses. Charlie does the same.

Bob receives two particles and performs a special type of measurement to entangle the particles that Alice and Charlie receive.

A real quantum theory, with no imaginary numbers, would predict different results than standard quantum physics, allowing the experiment to distinguish which one is correct.

Fan and colleagues performed such an experiment using photons, or particles of light, they report in a paper to be published in Physical Review Letters.

By studying how Alice, Charlie and Bob’s results compare across many measurements, Fan, Navascués and colleagues show that the data could be described only by a quantum theory with complex numbers.

Another team of physicists conducted an experiment based on the same concept using a quantum computer made with superconductors, materials which conduct electricity without resistance.

Those researchers, too, found that quantum physics requires complex numbers, they report in another paper to be published in Physical Review Letters.

“We are curious about why complex numbers are necessary and play a fundamental role in quantum mechanics,” says quantum physicist Chao-Yang Lu of the University of Science and Technology of China in Hefei, a coauthor of the study.

But the results don’t rule out all theories that eschew imaginary numbers, notes theoretical physicist Jerry Finkelstein of Lawrence Berkeley National Laboratory in California, who was not involved with the new studies.

The study eliminated certain theories based on real numbers, namely those that still follow the conventions of quantum mechanics. It’s still possible to explain the results without imaginary numbers by using a theory that breaks standard quantum rules.

But those theories run into other conceptual issues, making them “ugly,” he says. But “if you’re willing to put up with the ugliness, then you can have a real quantum theory.”

Despite the caveat, other physicists agree that the quandaries raised by the new findings are compelling.

“I find it intriguing when you ask questions about why is quantum mechanics the way it is,” says physicist Krister Shalm of the National Institute of Standards and Technology in Boulder, Colo.

Asking whether quantum theory could be simpler or if it contains anything unnecessary, “these are very interesting and thought-provoking questions.”

Source: https://www.sciencenews.org/article/quantum-physics-imaginary-numbers-math-reality

Exotic six-quark particle predicted by supercomputers

The predicted existence of an exotic particle made up of six elementary particles known as quarks by RIKEN researchers could deepen our understanding of how quarks combine to form the nuclei of atoms.

Quarks are the fundamental building blocks of matter. The nuclei of atoms consist of protons and neutrons, which are in turn made up of three quarks each.

Particles consisting of three quarks are collectively known as baryons.

Scientists have long pondered the existence of systems containing two baryons, which are known as dibaryons.

Only one dibaryon exists in nature—deuteron, a hydrogen nucleus made up of a proton and a neutron that are very lightly bound to each other.

Glimpses of other dibaryons have been caught in nuclear-physics experiments, but they had very fleeting existences.

"Although the deuteron is the only known stable dibaryon, many more dibaryons may exist," says Takuya Sugiura of the RIKEN Interdisciplinary Theoretical and Mathematical Sciences Program.

"It's important to study which pairs of baryons form dibaryons and which do not because this provides valuable insights into how quarks form matter."

Quantum chromodynamics is a highly successful theory that describes how quarks interact with each other.

But the strong coupling that occurs between quarks in baryons complicates quantum chromodynamics calculations. The computations become even more complex when considering bound states of baryons such as dibaryons.

Now, by calculating the force acting between two baryons each containing three charm quarks (one of the six types of quarks), Sugiura and his co-workers have predicted the existence of a dibaryon they called the charm di-Omega.

For this calculation, the team solved quantum chromodynamics with large-scale numerical calculations.

Since the calculations involved a vast number of variables, they used two powerful supercomputers: the K computer and the HOKUSAI supercomputer.

"We were extremely fortunate to have had access to the supercomputers, which dramatically reduced the cost and time to perform the calculations," says Sugiura.

"But it still took us several years to predict the existence of the charm di-Omega."

Despite the complexity of the calculations, the charm di-Omega is the simplest system for studying interactions between baryons. Sugiura and his team are now studying other charmed hadrons using the supercomputer Fugaku, which is the K computer's more powerful successor.

"We're especially interested in interactions between other particles containing charmed quarks," says Sugiura.

"We hope to shed light on the mystery of how quarks combine to form particles and what kind of particles can exist."

The research was published in Physical Review Letters.

Source: https://phys.org/news/2021-12-exotic-six-quark-particle-supercomputers.amp

NASA OFFICIALLY TOUCHES THE SUN — AND SOLVES A SOLAR MYSTERY

This is the closest encounter between our species and the Sun ever.

IN A FIRST for humanity, a manmade spacecraft has kissed the Sun.

“Not only does this milestone provide us with deeper insights into our Sun’s evolution and its impacts on our Solar System, but everything we learn about our own star also teaches us more about stars in the rest of the universe,” Thomas Zurbuchen, the associate administrator for the Science Mission Directorate, says in a press release.

WHAT’S NEW — NASA’s audacious Parker Solar Probe achieved the scientific first after three years and five Venus flybys, entering the Sun’s atmosphere on April 28, 2021.

The achievement was announced at a press conference at the American Geophysical Meeting Fall Meeting in New Orleans this week.

So why are we only learning about this incredible feat now? Well, NASA needed the intervening months to confirm they had actually done it — analyzing energy interactions recorded by the probe to try and mark the moment.

Ultimately, the signature of the Sun’s magnetic field was the smoking gun that verified we had really, actually, touched the Sun.

Since then, the probe has encountered the Sun twice more — once in August and once in November.

WHAT THEY FOUND — Already, this achievement is serving up serious insight into the Sun.

The first paper detailing fresh results from the probe was published Tuesday in Physical Review Letters, and there is another paper set to be published in The Astrophysical Journal soon.

The liminal space between the Sun’s atmosphere and space is called the Alfvén critical surface. Prior to the mission, physicists knew this dividing line was there but didn’t know precisely where.

Best estimates put it at 4.3 and 8.6 million miles above the surface of the Sun. But the Solar Probe complicates matters.

In April, the probe entered the Sun’s corona (another word for the atmosphere) at an altitude of 8.1 million miles above the surface of the Sun.

In doing so, the probe confirmed the Sun’s atmosphere isn’t uniform in shape — it is not some big sphere encasing the burning orb. Rather, it flows with peaks and valleys that the probe passed through repeatedly. At its closest approach, the probe came within 6.5 million miles of the surface of the Sun.

NEW DISCOVERIES — In its fly-through, the probe discovered two strange solar weather phenomena:

-A source of solar wind, known as switchbacks
-A pseudostreamer

Switchbacks are streams of charged particles that escape the Sun in a zig-zag-like pattern. Parker’s flyby proved that the photosphere — or surface — of the Sun generates these solar winds for the first time, although other regions of the Sun can generate them, too.

A pseudostreamer is a name given to huge structures that come forth from the Sun.

The agency compared it to the “eye of a storm,” because these structures are relatively calm compared to the surrounding environment.

As Parker Solar Probe passed through the corona on encounter nine, the spacecraft flew by structures...

WHAT IS THE PARKER SOLAR PROBE?

The Parker Solar Probe isn’t the first NASA mission to study the Sun. ESA also has a Sun-orbiter named Solar Orbiter (hopefully they didn’t spend too long on that name), but it has yet to have a close encounter — thus far, it’s only made it within 48 million miles, which wouldn’t even put it past Mercury’s orbit.

Parker wasn’t designed just to come near the Sun — it was designed to enter its atmosphere to settle the mystery of why the upper reaches of the corona are hotter than the surface of the Sun.

To do that, the probe is outfitted with a shield of carbon bricks able to withstand the unfathomably searing temperatures — up to 1.8 million degrees Fahrenheit.

To reach the Sun, the probe will go through a total of seven Venus flybys, which act like gravity slingshots to drop it close enough to the Sun to get inside the atmosphere.

A flyby in January will bring the craft within the corona again. The next Venus flyby is slated for 2023.

These initial results are just the tip of the iceberg (plasmaberg?) for Parker, which will eventually reach 3.83 million miles from the Sun’s surface.

Thanks to the new insight gained, the mission team will be able to further unlock the mysteries of our home star.

Source: https://www.inverse.com/science/we-touched-the-sun

NASA's James Webb Space Telescope launch: Live updates: https://www.space.com/news/live/james-webb-space-telescope-updates

James Webb: A $10bn machine in search of the end of darkness: https://www.bbc.com/news/science-environment-59476869.amp

Devvy4:
Vinny won the November best player of la liga, no one said anything about that here

Hmmm. Well deserved.

Quantum entanglement of two macroscopic objects is the Physics World 2021 Breakthrough of the Year: https://physicsworld.com/a/quantum-entanglement-of-two-macroscopic-objects-is-the-physics-world-2021-breakthrough-of-the-year/

1Sharon:
You can still marry AS but you will have to select pregnancies...

Please, shed more light on this.

If only Nigeria can toe the same path as China...

NASA's Webb telescope moved to meet its rocket

On Dec. 7, NASA's James Webb Space Telescope was transferred to the final assembly building at Europe's Spaceport in French Guiana to meet its Ariane 5 launch vehicle.

Stowed inside a special transport container and mobile clean room, Webb's vitals were meticulously monitored throughout the entire process of moving between buildings.

The Ariane 5 rocket Webb will ride to space was moved to the same building on Nov. 29. Here, adjustable platforms allow engineers to access the launch vehicle and its payload.

The next steps ahead are to safely lift Webb to an upper platform which has been prepared so that Webb can be connected to the Ariane 5's upper stage.

After being connected to the rocket, technicians will move forward to encapsulate Webb inside Ariane 5's specially adapted fairing.

In preparation for a Dec. 22 launch, ground teams have already successfully completed the delicate operation of loading the spacecraft with the propellant it will use to steer itself while in space.

Webb will be the largest, most powerful telescope ever launched into space.

As part of an international collaboration agreement, ESA (the European Space Agency) is providing the telescope's launch service. Working with partners, ESA was responsible for the development and qualification of Ariane 5 adaptations for the Webb mission.

Webb is an international partnership between NASA, ESA and the Canadian Space Agency (CSA).

Source: https://phys.org/news/2021-12-james-webb-space-telescope-rocket.html

OtemAtum, I also have another question please: I dream a lot, and over the years, I noticed many of my dreams come true; now, many times, my consciousness slips into a trance-like state where I start seeing things I don't know much about, don't understand, or that seem like memories of very distant events.

But before I can make sense of the things I saw (maybe it's a memory from a past life or a message from an unknown source), I would be jerked back to life involuntarily in fright because the trance-like states always seem as if one is staring death in the face.

Please, how do you think I can stay calm whenever my consciousness slips into such a state again naturally without my control so I can make sense of things I see?

The Webb Space Telescope Will Rewrite Cosmic History. If It Works.


https://www.youtube.com/watch?v=shPwW11MEHg


https://www.youtube.com/watch?v=qyWsJzbH0XI

Source: https://www.quantamagazine.org/why-nasas-james-webb-space-telescope-matters-so-much-20211203/

Technosignature from Proxima Centauri — and why astronomers rejected it

The forensic analysis of a potential signal from another civilization reveals how challenging the search for extraterrestrial intelligence is likely to become.

On 29 April 2019, the Parkes Radio Telescope in New South Wales, Australia, picked up an unusual signal while searching for signs of intelligent life elsewhere in the universe.

The telescope was observing Proxima Centauri, the nearest star to the sun and host to a number of exoplanets that are potentially habitable.

The search was part of a project called Breakthrough Listen, which is hunting for technosignatures from other civilizations.

These searches gather vast amounts of data. So the first task is to filter the interesting signals from the background.

In theory, a technosignature must have two important properties.

The first is that it must be confined to a narrowband of frequencies with high information content, just like radio broadcasts on Earth. No known natural process can produce signals like this.

The second is that the frequency of the signal must drift in a way that is consistent with the motion of an exoplanet relative to the Earth. The drift is the result of the relative accelerations which causes a slight Doppler shift.

So Sofia Sheikh at the University of California, Berkeley and colleagues created a filter that automatically separates signals with these properties from all the others the telescope picks up.

They found over 4 million of them.

Signal of interest



To help pick out false alarms, the telescope regularly switches from its target to point in other directions. That allowed Sheikh and co to discount any signals that continued in both periods. That left just 5160 hits.

The team further filtered out any signals in the range of known radio transmitters and any with a drift that corresponds to the motion of satellites.

That left a single unexplained event. The team describe it as a narrowband signal with characteristics broadly consistent with a technosignature, which appeared during a 2.5 hour period of observation but only when the telescope was pointing towards Proxima Centauri.

“The event does not lie within the frequency range of any known local radio-frequency interference, and has many characteristics consistent with a putative transmitter located in another stellar system,” say Sheikh and co.”

They called this signal of interest Breakthrough Listen Candidate 1 or BLC1 and it has been the subject of an extraordinary investigation.

Attributing a signal to an alien civilization is the hypothesis of last resort. Before that, every conventional explanation has to be explored and refuted.

So Sheikh and co undertook a remarkable investigation into the possibility of complex but conventional explanations.

They began by re-observing Proxima Centauri earlier this year, exactly two years after the first observation, to replicate as far as possible the initial observing conditions.

During these observations, they found no evidence of a signal similar to BLC1.

They then re-examined the possibility that a moving transmitter nearby could be the source—a car, train, helicopter, plane, balloon etc. Perhaps such a moving transmitter could reproduce the observed drift on BLC1.

The problem with this explanation is that BLC1 appeared for several hours. The team could find no reasonable trajectory that reproduced the drift for such a long period of time.

“It is extremely difficult to construct a continual motion path that could persist as exhibited by the measured signal, even by varying the speed along the route,” they concluded.

They came to a similar conclusion that satellites could not be the source. Low Earth Orbit satellites move too quickly to be observed over such a long period.

And geostationary satellites do not drift. Neither could have produced BLC1.

Then there are deep space probes in distant parts of the Solar System.

But the team were able to rule them out because none are in line with the telescope and Proxima Centauri and so could not be the source.

Next, the team looked for drifting signals, similar to BLC1, in data that had been originally rejected by their filtering algorithm. This required the researchers to visually inspect the data, looking for patterns similar to BLC1.

Amazingly, they found four examples of BLC1-like signals with a signal-to-noise ration so low that they had failed to reach the detection threshold of their algorithm.

They then looked for similar signals in the data gathered from other stars, some 7000 observations in total. Again, amazingly, they found 1 example of a signal similar to BLC1.

“All five of these 982 MHz signals from different days are fainter than BLC1; three of them conclusively appear in the off-sources, while two of them are inconclusive,” say Sheikh and co.

These five signals point to an alternative explanation—that BLC1 Is a complex form of radio interference that just happened to appear at the time the team were observing Proxima Centauri.

If this were true, thought the researchers, there ought to be other examples of similar patterns at other frequencies.

So again they went back to the original data and found 36 signals at other frequencies that looked like BLC1 but that had been filtered out by the search algorithm as obvious radio interference.

These signals had “strikingly similar morphology to blc1”.

Finally, the team looked for mirror images of the BLC1 signal—in other words signals with negative drift rates. Sure enough, they found 27 mirrored lookalikes.

All these appeared in data from observations when the telescope was pointing away from Proxima Centauri.

To determine the possible origin of these signals, the team looked at their common properties, whether they could be part of a harmonic sequence from a parent signal or had a more complex relationship.

Detective work

That’s when the origin became clear. They all appeared to be multiples of frequencies used in common clock oscillators.

That meant the signals were almost certainly generated by the interaction of ordinary digital electronic devices, probably from the radio frequency environment of the telescope facility itself.

In other words, the telescope was probably picking up its own radio frequency interference, albeit a complex and rare example of it.

The team have yet to identify the precise origin but say that should be possible with future studies.

That’s interesting work that reveals just how challenging the search of extraterrestrial technosignatures will be. BLC1 will contribute in its own way to future research.

As a result of this work, Sheikh and co have produced a checklist of steps that astronomers will have to work through whenever they find a signal of interest, to rule out the possibility of this kind of complex interference.

It also raises important questions about data storage. A feature part of this work was the ability to reanalyze data that had originally been discarded as noise.

That’s a significant amount of data that is hard to store. Just how much of this should be stored in future, in what format and for how long is up for debate.

But Sheikh and co have shown how important it can be: “Here we have learned that neglecting to consider the entire operable bandwidth of a receiver can have serious consequences.”

If humanity is to have confidence in future observations, the forensic analysis of BLC1 is likely to be foundational.

Source: https://astronomy.com/news/2021/12/technosignature-from-proxima-centauri--and-why-astronomers-rejected-it

OtemAtum:
I've tried over the years to avoid teaching things which are indirectly related to religion, e.g meditation, intercession, etc. I'm doing this in order not to be drawn into religion which I directly criticise. Anyway, concerning meditation, it has no specific method. A person have to try different methods until he finds the one that suits him most. For me, when I keep late night and sleep around 3 a.m to 4 a.m, that's when I usually achieve deep meditation. It might not suit someone else though.

I understand. I have tried different methods of meditation which I learnt in some books I read over the years. And I opted for a technique I read about in 2018 and combined it with the tips I learnt from you.

But the part that's not clear now is that word, critical used with meditation. Kindly shed light on this.

Then, I understand fasting can make one's meditation become deep.

� View Planet Parade in December �

Observers from the Earth will have a chance to spot the planet parade at the beginning of December. Five planets will gather in one sky area:
� Venus (-4.7m)
� Saturn (0.9m)
� Jupiter (-1.8 )
� Neptun (7.7)
� Uranus (6.0)

The dwarf planet Ceres (6.9), a large asteroid Pallas (7.6), and the Moon (-11.4) will settle nearby.

The best time to observe them is December 12, 2021; look for the celestial objects right after sunset. Venus, Saturn, Jupiter, and the Moon will be visible to the naked eye. A pair of binoculars or a small telescope will help you to see the dimmer Neptune, Uranus, Ceres, and Pallas. �

* Although there is now an official scientific definition of the term “planet parade,” astronomers use it to denote an astronomical event that happens when Solar System planets line up in the same sky area as seen from the Earth.
Source: Star Walk

dazzlingd:
Watz up, got your dm but I dont have access to the email of this account, send me an email I can reach you on

Okay...

What is an Exoplanet?

An exoplanet, or extrasolar planet, is a planet outside of our solar system that usually orbits another star in our galaxy.


https://www.youtube.com/watch?v=0ZOhJe_7GrE

Most of the exoplanets discovered so far are in a relatively small region of our galaxy, the Milky Way. ("Small" meaning within thousands of light-years of our solar system; one light-year equals 5.88 trillion miles, or 9.46 trillion kilometers.)

That is as far as current telescopes have been able to probe. We know from NASA’s Kepler Space Telescope that there are more planets than stars in the galaxy.

Although exoplanets are far – even the closest known exoplanet to Earth, Proxima Centauri b, is still about 4 light-years away – scientists have discovered creative ways to spot these seemingly tiny objects.

How do we find exoplanets?

There are five methods scientists commonly use to discover exoplanets.

The two main techniques are the transit and radial velocity methods.

When a planet passes directly between an observer and the star it orbits, it blocks some of that starlight. For a brief period of time, that star’s light actually gets dimmer.

It's a tiny change, but it's enough to clue astronomers in to the presence of an exoplanet around a distant star. This is known as the transit method.

Orbiting planets cause stars to wobble in space, changing the color of light astronomers see when observing a star.

Stars are affected by the gravitational tug of their orbiting planets and, when observed through a telescope, this affects the star's light spectrum. If the star moves in the direction of the observer it will appear to be shifted toward blue.

If it is moving away from the observer, it will shift toward the red. Observing this is known as the radial velocity method.

NASA’s exoplanet space telescopes
Thousands of exoplanets have been discovered and confirmed orbiting other stars.

The first evidence of exoplanets dates to 1917 when Van Maanen identified the first polluted white dwarf, however, the first confirmed detection of an exoplanet would not come until the 1990s.

The discovery of exoplanets grew exponentially in the years to follow with the launch of the Kepler Space Telescope.

The Kepler mission was specifically designed to survey our region of the Milky Way galaxy to discover hundreds of Earth-size and smaller planets in or near the habitable zone (also called the “Godilocks zone,” the area around a star where rocky planets could have liquid water on the surface) and determine the fraction of stars that might have such planets around them.

After the second of Kepler’s four gyroscope-like wheels failed in 2013, Kepler completed its prime mission that November and began its extended mission, K2.

The spacecraft was retired in 2018, but Kepler data are still being used to find exoplanets (more than 2,700 confirmed so far).

NASA’s Spitzer Space Telescope (2013-2020) was not designed to search for exoplanets, but its infrared instruments made it an excellent exoplanet explorer. It was used in the notable discovery of the TRAPPIST-1 system.

In 2018 the Transiting Exoplanet Survey Satellite (TESS) was launched as a successor to Kepler to discover exoplanets in orbit around the brightest dwarf stars, the most common star type in our galaxy.

Future space missions such as NASA’s James Webb Space Telescope and the Nancy Grace Roman Space Telescope hold great promise for what we can learn from exoplanets.

Through spectroscopy, reading light signatures for information, astronomers hope to learn more about planet atmospheres and the conditions of the planets themselves.

Confirmed vs. candidate
Fast facts
What is an exoplanet candidate?
An exoplanet candidate is a likely planet discovered by a telescope but has not yet been proven to actually exist.

It is possible for some candidates to turn out to be "false positives." A planet is considered "confirmed" once it is verified through additional observation using two other telescopes.

There are currently thousands of planet candidates awaiting confirmation. But time on telescopes is considered a precious resource and it takes a lot of computing time to find which targets to investigate.

This is one area where amateur scientists can work with NASA data to help refine targets and even discover exoplanets. Where computers might miss a single transit, humans can detect small brightness dips in data that might tell us there is a planet to be found.

How do we name exoplanets?

Exoplanet names can look long and complicated at first, especially when compared to names like Venus and Mars.

However, there is a logic behind their naming system that is important to how scientists catalog thousands of planets.

Astronomers differentiate between the alphanumeric "designations" and alphabetical "proper names." All stars and exoplanets have designations, but very few have proper names.

The first part of an exoplanet name is usually the telescope or survey that discovered it. The number is the order in which the star was cataloged by position.

The lowercase letter stands for the planet, in the order in which the planet was found. The first planet found is always named b, with ensuing planets named c, d, e, f and so on.

The star that the exoplanet orbits is usually the undeclared "A" of the system, which can be useful if the system contains many stars, which themselves may be designated B or C.

(Stars get capital letters; planets receive lowercase designations.)

If a bunch of exoplanets around the same star are found at once, the planet closest to its star is named b with more distant planets named c, d, e and so on.

An example of an exoplanet name is Kepler-16b, where "Kepler" is the name of the telescope that observed the system, 16 is the order in which the star was cataloged and "b" is the closest planet to the star.

If we were naming Earth as an exoplanet, it would be called Sun d (Sun is the name of our star, and Earth is the third planet, starting with b, Mercury).

https://exoplanets.nasa.gov/what-is-an-exoplanet/in-depth/

Are we alone in the universe? Revisiting the Drake equation


A revised version of the Drake equation, a mathematical formula for the probability of finding life or advanced civilizations in the universe.

Are humans unique and alone in the vast universe? This question--summed up in the famous Drake equation--has for a half-century been one of the most intractable and uncertain in science.

But a new paper shows that the recent discoveries of exoplanets combined with a broader approach to the question makes it possible to assign a new empirically valid probability to whether any other advanced technological civilizations have ever existed.

And it shows that unless the odds of advanced life evolving on a habitable planet are astonishingly low, then human kind is not the universe’s first technological, or advanced, civilization.

The paper, published in Astrobiology, also shows for the first time just what “pessimism” or “optimism” mean when it comes to estimating the likelihood of advanced extraterrestrial life.

“The question of whether advanced civilizations exist elsewhere in the universe has always been vexed with three large uncertainties in the Drake equation,” said Adam Frank, professor of physics and astronomy at the University of Rochester and co-author of the paper.

“We’ve known for a long time approximately how many stars exist. We didn’t know how many of those stars had planets that could potentially harbor life, how often life might evolve and lead to intelligent beings, and how long any civilizations might last before becoming extinct.”

“Of course, we have no idea how likely it is that an intelligent technological species will evolve on a given habitable planet,” says Frank.

"But using our method we can tell exactly how low that probability would have to be for us to be the ONLY civilization the Universe has produced. We call that the pessimism line. If the actual probability is greater than the pessimism line, then a technological species and civilization has likely happened before.”

Using this approach, Frank and Sullivan calculate how unlikely advanced life must be if there has never been another example among the universe’s ten billion trillion stars, or even among our own Milky Way galaxy’s hundred billion.

"Rather than asking how many civilizations may exist now, we ask ‘Are we the only technological species that has ever arisen?'"
- Woodruff Sullivan, University of Washington

The result? By applying the new exoplanet data to the universe’s 2 x 10 to the 22nd power stars, Frank and Sullivan find that human civilization is likely to be unique in the cosmos only if the odds of a civilization developing on a habitable planet are less than about one in 10 billion trillion, or one part in 10 to the 22nd power.

“One in 10 billion trillion is incredibly small,” says Frank.

“To me, this implies that other intelligent, technology producing species very likely have evolved before us. Think of it this way.

Before our result you’d be considered a pessimist if you imagined the probability of evolving a civilization on a habitable planet were, say, one in a trillion.

But even that guess, one chance in a trillion, implies that what has happened here on Earth with humanity has in fact happened about a 10 billion other times over cosmic history!”

For smaller volumes the numbers are less extreme.

For example, another technological species likely has evolved on a habitable planet in our own Milky Way galaxy if the odds against it evolving on any one habitable planet are better than one chance in 60 billion.

But if those numbers seem to give ammunition to the “optimists” about the existence of alien civilizations, Sullivan points out that the full Drake equation—which calculates the odds that other civilizations are around today—may give solace to the pessimists.

“Thanks to NASA's Kepler satellite and other searches, we now know that roughly one-fifth of stars have planets in “habitable zones,” where temperatures could support life as we know it. So one of the three big uncertainties has now been constrained.”

Frank said that the third big question--how long civilizations might survive--is still completely unknown.

“The fact that humans have had rudimentary technology for roughly ten thousand years doesn’t really tell us if other societies would last that long or perhaps much longer,” he explained.

But Frank and his coauthor, Woodruff Sullivan of the astronomy department and astrobiology program at the University of Washington, found they could eliminate that term altogether by simply expanding the question.

“Rather than asking how many civilizations may exist now, we ask ‘Are we the only technological species that has ever arisen?" said Sullivan.

“This shifted focus eliminates the uncertainty of the civilization lifetime question and allows us to address what we call the ‘cosmic archaeological question’—how often in the history of the universe has life evolved to an advanced state?”

That still leaves huge uncertainties in calculating the probability for advanced life to evolve on habitable planets.

It's here that Frank and Sullivan flip the question around.

Rather than guessing at the odds of advanced life developing, they calculate the odds against it occurring in order for humanity to be the only advanced civilization in the entire history of the observable universe.

With that, Frank and Sullivan then calculated the line between a Universe where humanity has been the sole experiment in civilization and one where others have come before us.

In 1961, astrophysicist Frank Drake developed an equation to estimate the number of advanced civilizations likely to exist in the Milky Way galaxy.

The Drake equation (top row) has proven to be a durable framework for research, and space technology has advanced scientists' knowledge of several variables.

But it is impossible to do anything more than guess at variables such as L, the probably longevity of other advanced civilizations.

In new research, Adam Frank and Woodruff Sullivan offer a new equation (bottom row) to address a slightly different question: What is the number of advanced civilizations likely to have developed over the history of the observable universe?

Frank and Sullivan's equation draws on Drake's, but eliminates the need for L.

Their argument hinges upon the recent discovery of how many planets exist and how many of those lie in what scientists call the “habitable zone” – planets in which liquid water, and therefore life, could exist. This allows Frank and Sullivan to define a number they call Nast.

Nast is the product of N*, the total number of stars; fp, the fraction of those stars that form planets; and np, the average number of those planets in the habitable zones of their stars.

They then set out what they call the “Archaelogical-form” of the Drake equation, which defines A as the “number of technological species that have ever formed over the history of the observable Universe.”

Their equation, A=Nast*fbt, describes A as the product of Nast – the number of habitable planets in a given volume of the Universe – multiplied by fbt – the likelihood of a technological species arising on one of these planets.

The volume considered could be, for example, the entire Universe, or just our Galaxy.

“The universe is more than 13 billion years old,” said Sullivan. “That means that even if there have been a thousand civilizations in our own galaxy, if they live only as long as we have been around—roughly ten thousand years—then all of them are likely already extinct.

And others won’t evolve until we are long gone. For us to have much chance of success in finding another "contemporary" active technological civilization, on average they must last much longer than our present lifetime.”

“Given the vast distances between stars and the fixed speed of light we might never really be able to have a conversation with another civilization anyway,” said Frank. “If they were 20,000 light years away then every exchange would take 40,000 years to go back and forth.”

But, as Frank and Sullivan point out, even if there aren’t other civilizations in our galaxy to communicate with now, the new result still has a profound scientific and philosophical importance.

“From a fundamental perspective the question is ‘has it ever happened anywhere before?’” said Frank.

"Our result is the first time anyone has been able to set any empirical answer for that question and it is astonishingly likely that we are not the only time and place that an advance civilization has evolved.”

According to Frank and Sullivan their result has a practical application as well. As humanity faces its crisis in sustainability and climate change we can wonder if other civilization-building species on other planets have gone through a similar bottleneck and made it to the other side.

As Frank puts it “We don’t even know if it’s possible to have a high-tech civilization that lasts more than a few centuries.”

With Frank and Sullivan’s new result, scientists can begin using everything they know about planets and climate to begin modeling the interactions of an energy-intensive species with their home world knowing that a large sample of such cases has already existed in the cosmos.

“Our results imply that our evolution has not been unique and has probably happened many times before. The other cases are likely to include many energy intensive civilizations dealing with their feedbacks onto their planets as their civilizations grow.

That means we can begin exploring the problem using simulations to get a sense of what leads to long lived civilizations and what doesn’t.”

Source: https://exoplanets.nasa.gov/news/1350/are-we-alone-in-the-universe-revisiting-the-drake-equation/

Image below: This artist’s conception of a planetary lineup shows habitable zone planets with similarities to Earth: from left, Kepler-22b, Kepler-69c, Kepler-452b, Kepler-62f and Kepler-186f. Last in line is Earth itself. Credit: NASA/JPL-Caltech

Drake Equation

How many alien societies exist, and are detectable?

This famous formula (equation above) gives us an idea. The Drake Equation, which was the agenda for a meeting of experts held in West Virginia in 1961, estimates N, the number of transmitting societies in the Milky Way galaxy. The terms are defined in the images above.

Understanding the Drake Equation

This simple formulation is generally agreed to be the “second most-famous equation in science (after E= mc2),” and you can find it in nearly every astronomy textbook.

The Drake Equation was cooked up by astronomer Frank Drake in 1961 to serve as the agenda for the first meeting on the topic of SETI.

In 1960, Drake had conducted a pioneering search for extraterrestrial signals – a several-week long effort he named Project Ozma.

Somewhat unexpectedly, this modest experiment attracted a great deal of attention, and Drake was encouraged by J.P.T. Pearman, a staff officer at the National Academy of Sciences, to organize an informal gathering of accomplished researchers and engineers to discuss the prospects for finding a signal.

Was listening for radio signals a worthy endeavor or not?

Approximately a dozen people attended this informal meeting, and they all were eminent.

Among them was biochemist Melvin Calvin (who received a call during the meeting notifying him that he had just won the Nobel Prize), biologist Joshua Lederberg, physicist Philip Morrison, and planetary astronomer Carl Sagan, as well as Peter Pearman and self-invited guest Barney Oliver, a highly accomplished radio engineer.

The conference took place at the Green Bank Observatory – the site of Project Ozma – in November 1961.

While planning the event, Drake chose to organize the discussion around a simple formula he concocted that estimated a critical number for SETI, namely the estimated count of transmitting worlds in the Galaxy.

His equation is comprised of seven factors which, when multiplied together, yield the number of societies that are now broadcasting signals one might conceivably pick up. The factors are listed and defined above.

As Drake himself has noted, his simple formula can be likened to how you might estimate the number of students at a university.

All you need to do is consider the number of new students (freshmen) entering each year and multiply that by the average number of years the students will spend at the school (four years.) Voila, you have a good estimate of the total number of undergraduate students.

The Drake Equation is constructed with similar logic. The first six terms, when multiplied together, yield the average number of new technologically transmitting societies that come on-line in the Milky Way galaxy each year.

This “freshman” rate is then multiplied by the equation’s last term, L: the average lifetime they stay on the air. The result is N, the average number of transmitting societies in the Galaxy now.

Clearly, if this number is very small, then the chances of a signal detection by SETI are also small. Conversely, a large value of N would be incentive to press the search.

At the time of the meeting, essentially none of the seven factors in the equation was known excepting the first, the production rate of stars.

Nonetheless, the attendees bandied about their best guesses for the other terms, concluding that the “freshman” rate was on the order of one.

In other words, new transmitting societies appear once a year somewhere in the Milky Way. All that remains is to multiply this by the lifetime of such a broadcasting civilization.

This last term, L, is obviously dependent on alien behavior. It’s not a factor we can quantify with studies in astronomy or biology.

Our own experience also doesn’t help much. We’ve been transmitting on a widescale basis, and at frequencies and powers that might conceivably be picked up by someone in another solar system, for less than a century.

How long will we continue to do this? Some people think that humanity is hellbent on self-annihilation, and the value of L for Homo sapienswill be merely a century or two. Others are less dramatic and more optimistic.

But obviously we have little basis for estimating L.

Due to such uncertainties, estimates for N have ranged from 1 (Earth houses the only galactic society that is transmitting) to several million, Drake himself currently suggests that N = 10,000 (the consequence of assuming that new transmitting societies are produced at intervals of one per year and enjoy an average lifetime of 10,000 years).

It has been sixty years since the Drake Equation was conceived. Have we nailed down more of the terms than the single one known in 1961?

Sadly, no. In fact, we’ve made little progress in this regard apart from the terms giving the fraction of new stars sporting planets, and (to a lesser degree) the average number of planets per solar system suitable for complex life.

The attendees of the 1961 Green Bank meeting thought it likely that the former was close to 100 percent, and the latter was approximately one.

Both guesses are within a factor of two or three of modern estimates, based on the discoveries of thousands of exoplanets since 1995.

It’s worth noting that many people have suggested amendments to the Drake Equation, adding terms to account for facts that don’t seem to be part of the original formula, such as colonization of other star systems by ambitious societies.

Others have proffered changes to the math, replacing single terms with mathematical distributions. But according to Drake, none of these refinements is necessary nor do they alter the equation in any essential and substantive way.

While the Drake Equation cannot be “solved” or even accurately calculated, it retains considerable utility for discussions about extraterrestrial life and intelligence.

And that, after all, was the reason for its invention. It’s also noteworthy that this famous formulation encompasses all the research activities of the SETI Institute, from our efforts to probe the harsh landscapes of Mars to our extremely high-tech searches for alien signals. It is the scaffolding upon which the Institute has been built.

There are 100 scientists at the SETI Institute, working on nearly 100 research questions. But each of these topics can be related to one of the terms in the Drake Equation.

N: Are technological societies common or not? Our ATA radio telescope is looking for signals coming from other star systems that would help answer that question.

Source: https://www.seti.org/drake-equation-index

Frank Drake's image below:

OtemAtum, what key things do you think scientists are missing in the Search for Extraterrestrial Intelligence (SETI)?

If other beings (human-like entities, animals, plants) exist on other planets as you say, why haven't they made contact with us? Are they hiding from us?

What do you think about the Great Filter? Do you think the Homo Erectus epoch also faced the same problem of Great Filter?

Sorry for my plenty questions. Kindly answer them and the one on your main thread.

Thanks.

What is the Fermi Paradox?

The Fermi Paradox asks "Where is everybody?"

The Fermi Paradox refers to the dichotomy between the high probability that extraterrestrial intelligence exists and the fact that we have no evidence for such aliens.

This paradox was described by the late British science-fiction author, Sir Arthur C. Clarke, who said: "Two possibilities exist: Either we are alone in the universe or we are not. Both are equally terrifying."

Many experts since have grappled with the same question.

Why, considering the multitude of planets and stars in the Milky Way, have we not heard from anyone?

We call this problem the Fermi Paradox, and there are a number of possible solutions — some more unnerving than others …

WHAT IS THE FERMI PARADOX?

The Fermi Paradox is a problem that asks, where are all the aliens in the universe? If life is so abundant, why haven't we been visited by, or heard from, anyone else?

According to NASA, in just the last two decades we have found more than 4,000 planets beyond our solar system, with trillions of stars thought to exist in our galaxy — most of which host their own planets.

Considering life sprang up on Earth, would we not have expected it to start in at least one other location in the last 14 billion years of the universe?

WHO CAME UP WITH THE FERMI PARADOX?

The Fermi Paradox was devised by the Italian-American physicist Enrico Fermi, according to the Planetary Society.

He is said to have come up with the idea in a throwaway remark over lunch with colleagues in 1950 when he asked "Where is everybody?"

He wondered, given that our planet was relatively young compared to the universe, we might have expected someone to have visited us by now — but we had no evidence of that ever occurring.

Fermi died four years later, in 1954, so did not have long to ponder the question.

But his idea has sparked whole fields of science hoping to solve the problem, including the search for extraterrestrial intelligence (SETI).

WHAT ARE THE SOLUTIONS TO THE FERMI PARADOX?

There are a number of solutions to the Fermi Paradox. The most obvious, and likely, is that we simply haven't looked hard enough to find other life, and interstellar travel between stars is difficult.

The first planets beyond our own solar system were only discovered in the 1990s. This means we have barely started to scratch the surface of studying other worlds.

For example, we are yet to find many planets that look exactly like Earth, orbiting stars like our sun — but upcoming telescopes are hoped to be capable of such detections in the coming decade or two.

Even then, the distances between star systems are enormous, making journeys between them difficult. Our closest star system for example, Alpha Centauri, is four light-years away.

The distance from Earth to Neptune, for comparison, is 0.0005 light-years — a journey that would still take us decades with current technology.

Intelligent aliens might simply have decided to never visit us, or did so long ago without leaving any trace.

Alternatively, it might be that life is simply so rare that the chances of two intelligent species being positioned relatively near each other in the vastness of space is exceedingly slim.

A more somber suggestion is that we are alone in the universe. Life, like that found on Earth, is simply so vanishingly unlikely to arise, that ours was the only world where this happened.

Most scientists think this is unlikely. But there is the possibility that some sort of event, known as a Great Filter, might prevent civilizations like our own from progressing far enough to make contact elsewhere.

WHAT IS THE GREAT FILTER?

The Great Filter is the idea that catastrophic events, either manmade or natural, cause intelligent life to be extinguished on habitable worlds before they have a chance to extend their reach into the universe.

These events could be one of many things. They might be powerful solar flares, climate change, asteroid impacts, or perhaps something of the planet's own doing like a nuclear apocalypse.

If this idea is correct, it's not clear if we have already passed this filter — or we are yet to reach it …

WHAT IS THE DRAKE EQUATION?

The Drake equation is an idea, proposed by the American astronomer Frank Drake in 1961, that the number of potential civilizations in the universe can be calculated if we know a few key variables.

The formula for the Drake equation is:

N = R* x �p x ne x �1 x �i x �c x L

R* = average rate of star formation in Milky Way

�p = fraction of stars supporting planets

ne = average number of planets that could potentially support life for each star that hosts planets

�1 = fraction of those planets that "could" support life that actually develop life

�i = fraction of planets that develop intelligent life, and thus intelligent civilizations

�c = fraction of those civilizations that develop a technology to communicate their existence

L = length of time over which these civilizations send those detectable signals into space

By including all of these factors in the equation, the idea is you might be able to work out how many other intelligent civilizations exist in the universe.

This "simple" formula, Drake once said, would be akin to estimating the number of students at a university by multiplying the number of new students entering each year by the average number of years a student will spend at a university, according to SETI.

As of yet, however, a number of key variables in the equation remain unknown, meaning we can't yet come up with a possible number for other species of intelligent life.

CAN WE SOLVE THE FERMI PARADOX?

Many scientists hope that we can solve the Fermi Paradox. Upcoming telescopes, like NASA's James Webb Space Telescope launching in December 2021, will be able to study the atmospheres of exoplanets like never before, while the search for new planets is continuing unabated.

By finding more planets in habitable zones around their stars, where temperatures are just right for liquid water to exist, scientists could narrow down the possibility of other Earth-like worlds in the universe — and, by using advanced telescopes, study some of these Earth-like orbs in our galaxy.

Ultimately, scientists simply need more data in order to truly understand the Fermi Paradox. But if it turns out that habitable planets are common, and astronomers are still yet to hear from anyone, then it might suggest intelligent life such as that on Earth is rare.

ARE WE ALONE IN THE UNIVERSE?

We don't know if we are alone in the universe, but scientists hope to answer this question in the coming years.

Ongoing missions, like NASA's Perseverance rover on Mars, could give us vital clues. Perseverance is collecting samples that will be returned to Earth in the 2030s and could contain signs of past or present life on Mars.

If we can discover even simple life on Mars or another location, like an icy moon of Jupiter or Saturn such as Europa and Enceladus, that would be proof that life had sprung up in at least two locations — Earth and this other world.

In that instance, it would suggest life is not just limited to our own planet. With that, it would raise the prospect that other intelligent life, like us, might well exist in our galaxy and beyond.

Source: https://www.livescience.com/fermi-paradox
Cc: OtemAtum

HellVictorinho3:
Krauss is not a reason why you should do these things.


Can you still find something in your heart towards helping my dad or brother?

It's a serious matter.


Don't let the name Krauss stop you from being generous.


Remember that we're all humans.


On behalf of my brother/dad,
Please?

I'm sorry I can't be of help at this moment. Hopefully, I will be able to soon.

wirinet:
You guys cut it out. Don't spoil this thread. We have been conducting ourselves creditably before now. Don't let us degenerate into insults and intolerance just because of differences in beliefs and opinions like our theist counterparts.

The guy is better ignored.

When a person has a single-digit IQ, he would regard my citing of the book of the theoretical physicist as worshipping him.

Hating on someone that doesn't even know you exist. Isn't that the height of stupidity?

Yet, if you've the opportunity to meet eminent personalities like Kraus who is a leader in his field, you can never say all this tripe to his face.

Some nonentities on Nairaland are irredeemably stupid and better ignored.

Better to ignore some comments by some nonentities on this forum.

DeepSight:
[s]Enjoy your ignorance bro.
Its your life.
Or your nothingness.[/s]

Too many low IQ members on Nairaland who can't understand simple statements written in simple English.

DeepSight:
[s]Of course small and limited minds are prone to hero-worship: and ground their thoughts around appeals to authority.
It takes larger, freer and open minds to question even the so called acclaimed.

If Einstein and others didnt question Newtonian physics, you wouldnt be here rambling on about quantum physics would you? Is Newton not one of the most brilliant men ever?

Do people not have valid questions even against the postulations of some of the most acclaimed scientists? Do such acclaimed scientists not turn out to be wrong sometimes - oh you who know the history of science?

Lawrence Krauss' postulations on nothingness are sheer iidiocy, and if you are so star struck by him that you cannot think for yourself on something so self evident, that is your cup of tea. Do not expect that everyone else will engage in your worship of that re.tard.
[/s]

Your ill-informed opinion has been read and duly discarded.

Stop quoting my posts.

DeepSight:
[s]And you are completely ignorant of both science and logic.

You don't even pause to contemplate what the implications of nothingness changing are.
Nor does it help that you say "whats seen as nothing" - for that only infers the seers of such nothingness to be potential psychiatric patients.
Like Lawrence Krauss. [/s]

You can crawl back into the hole you came out from and stop quoting me.

An unknown entity on Nairaland is calling a successful theoretical physicist a first-class idiot

One can only find nonentities like this on Nairaland.