Here’s What You Do With Two-Thirds of the World’s Jets When They Can’t Fly
Just finding space to park can be a problem, and idle planes require a surprising amount of work, from maintaining hydraulics to stopping birds from nesting.
Saturday, 27 June 2020
Wednesday, 17 June 2020
There could be 36 communicating intelligent civilizations in our galaxy, study says
(CNN)Earth has proven unique in its ability to host life in the universe so far, leading us to question if we're truly alone.
Maybe we're not.
Scientists have calculated that there could be a minimum of 36 active, communicating intelligent civilizations in our Milky Way galaxy, according to a new study. However, due to time and distance, we may never actually know if they exist or ever existed.
The study published Monday in The Astrophysical Journal.
Previous calculations along these lines have been based on the Drake equation, which was written by astronomer and astrophysicist Frank Drake in 1961.
"Drake developed an equation which in principle can be used to calculate how many Communicating Extra-Terrestrial Intelligent (CETI) civilizations there may be in the Galaxy," the authors wrote in their study. "However, many of its terms are unknowable and other methods must be used to calculate the likely number of communicating civilizations."
So scientists at the University of Nottingham developed their own approach.
"The key difference between our calculation and previous ones based on the Drake equation is that we make very simple assumptions about how life developed," said study coauthor Christopher Conselice, a professor of astrophysics at the University of Nottingham, in an email to CNN.
"One of them is that life forms in a scientific way — that is if the right conditions are met then life will form. This avoids impossible to answer questions such as 'what fraction of planets in a habitable zone of a star will form life?' and 'what fraction of life will evolve into intelligent life?' as these are not answerable until we actually detect life, which we have not yet done."
They developed what they call the Astrobiological Copernican Principle to establish weak and strong limits on life in the galaxy. These equations include the history of star formation in our galaxy and the ages of stars, the metal content of the stars and the likelihood of stars hosting Earth-like planets in their habitable zones where life could form.
The habitable zone is the right distance from a star, not too hot or too cold, where liquid water and life as we know it may be possible on the surface of a planet.
Of these factors, habitable zones are critical, but orbiting a quiet, stable star for billions of years may be the most critical, Conselice said.
"The two Astrobiological Copernican limits are that intelligent life forms in less than 5 billion years, or after about 5 billion years — similar to on Earth where a communicating civilization formed after 4.5 billion years," said coauthor Tom Westby, an assistant professor in the University of Nottingham's faculty of engineering, in a statement.
The Astrobiological Copernican Strong limit is that life must form between 4.5 to 5.5 billion years, as on Earth, while the weak limit is that a planet takes at least 4 billion years to form life, but it can form anytime after that, the researchers said.
"It is called the Astrobiological Copernican Principle because it makes the assumption that our existence is not special," Conselice said. "That is, if the conditions in which intelligent life on Earth also developed somewhere else in the Galaxy then intelligent life would develop there in a similar way."
Based on their calculations using the Astrobiological Copernican Strong limit, they determined that there are likely 36 active and communicating intelligent civilizations across our galaxy. This assumes that life forms the way it does on Earth — which is our only understanding of it at the moment. It also assumes that the metal content of the stars hosting these planets are equal to that of our sun, which is rich in metals, Westby said.
The researchers believed the strong limit is the most likely because "it still allows intelligent life to form within a billion years after it did on Earth, which seems like plenty of time," Conselice said.
Another assumption of these potential civilizations is that they're making their presence known in some way via signals.Currently, we've only been producing signals like radio transmissions from satellites and televisions for a short time. Our "technological" civilization is about a hundred years old. So imagine about 36 others doing the same thing across the galaxy. The researchers were surprised that the number was so small — but not zero. "That is fairly remarkable," Conselice said. Even though this study only looked at our galaxy, distance is an inhibiting factor. The researchers calculated that the average distance between these potential civilizations would equal about 17,000 light-years. Detecting those signals or sending communications using current technology would take so long that it would be nearly impossible.
The search for intelligent life is only expected to yield a positive observation if the average life-span of [communicating extra-terrestrial intelligence] within our Galaxy is 3,060 years. That is to say, our communicating civilization here on Earth will need to persist for 6,120 years beyond the advent of long-range radio technology (approximately 100 years ago) before we can expect a [search for extra-terrestrial intelligence] two-way communication."
Under the more relaxed assumptions of the Weak Copernican case, there would be a minimum of 928 civilizations communicating in our galaxy today, according to the study, meaning more of them at closer range. This would only require about 700 years to make a detection.
Life span of a civilization
"It is clear that the lifetime of a communicating civilization is the key aspect within this problem, and very long lifetimes are needed for those within the Galaxy to contain even a few possible active contemporary civilizations," the researchers wrote in their study.
And then there's the question of survival. Are other potential civilizations as long-lived as those on Earth?
If the search for this life reveals nothing within a distance of 7,000 light-years, the researchers suggest that this could mean one of two things.
First, it could suggest that the lifetimes of these civilizations are shorter than 2,000 years — which could mean that our own is nearing its end.
Second, it could suggest that life on Earth is unique and occurs in a much more random process than the Astrobiological Copernican Limits established in the study.
Not all factors or limitations were included in the study, like the fact that the small M-dwarf stars these Earth-like planets may be orbiting may release harmful radiation "that would make life difficult to exist," which is a debated issue, Conselice said. M-dwarf stars are common in our galaxy and have been known to host rocky, Earth-size planets.
Next, the researchers will look beyond our galaxy to see if life may exist outside of its boundaries.
"Our new research suggests that searches for extraterrestrial intelligent civilizations not only reveals the existence of how life forms, but also gives us clues for how long our own civilization will last," Conselice said.
"If we find that intelligent life is common then this would reveal that our civilization could exist for much longer than a few hundred years, alternatively if we find that there are no active civilizations in our Galaxy it is a bad sign for our own long-term existence. By searching for extraterrestrial intelligent life — even if we find nothing — we are discovering our own future and fate."
Monday, 1 June 2020
Trump mobilizes US military to end unprecedented riots
By Ebony Bowden
US President Donald Trump holds up a bible in front of St John's Episcopal church after walking across Lafayette Park from the White House.AFP via Getty Images
WASHINGTON — President Trump on Monday invoked a law from 1807 allowing him to send military forces to states rocked by unrest over the death of George Floyd in a sudden White House Rose Garden address interrupted by the sounds of protestors being cleared out by police nearby.
“We cannot allow the righteous cries of peaceful protesters to be drowned out by an angry mob,” Trump said, declaring himself the “president of law and order” while blaming extremist groups such as Antifa for the unrest.
“I am mobilizing all available federal resources, civilian and military, to stop rioting and looting, to end the destruction,” he said, immediately mobilizing the Insurrection Act of 1807, which allows him to deploy troops anywhere across the nation.
It was last used in 1992, by President George H.W. Bush to quell the LA riots, which were sparked by the police beating of Rodney King.
“If a city or state refuses to take the actions that are necessary to defend the life and property of their residents, then I will deploy the United States military and quickly solve the problem for them,” Trump said of the act.
Under the Civil War-era Posse Comitatus Act, federal troops are prohibited from performing domestic law enforcement actions such as making arrests, seizing property or searching people. In extreme cases, however, the president can invoke the Insurrection Act, which allows the use of active-duty or National Guard troops for law enforcement.
The president’s last-minute address came in juxtaposition to the scene outside, where a series of military vehicles rolled out front on Pennsylvania Avenue and military police and law enforcement clashed with protesters at Lafayette Park, firing tear gas, flash bangs, rubber bullets and pepper spray on a large but peaceful crowd.
.....
Trump described the scenes of violent rioting and looting which have rocked the nation for the past week as a “total disgrace” and said anyone who didn’t respect curfew orders would be “prosecuted to the fullest extent of the law.”
“I am taking these actions today to reaffirm resolve and with a true and passionate love for our country, by far our great days lie ahead,” he said as chaos unfolded in the streets around the White House.
Following his address, Trump walked out of the front of the White House gates, through Lafayette Park to Washington’s historic St John’s Episcopal Church which was partly destroyed in a fire lit by rioters on Sunday evening.
Attorney General William Barr, Defense Secretary Mark Esper and chief of staff Mark Meadows were among the high-ranking officials with Trump, who posed for photos outside the boarded-up church, holding a Bible, where protesters had been demonstrating just minutes earlier.
The police made the aggressive advance on more than a thousand protesters outside the executive address following days of unrest across the nation over the death of George Floyd in police custody.
Earlier Monday, President Trump lashed into governors for their response to the week-long crisis — calling them “weak” and telling them to needed to take control of the unrest following Floyd’s death.
On May 1, 1992, Bush deployed 4,000 Army and Marine troops to South Central Los Angeles in the effort to end two days of rampant rioting that included 40 people killed, more than 1,500 injured, more than 3,700 fires and more than 3,000 arrests, the Washington Post reported at the time.
Bush addressed the nation that day, saying the violence in Los Angeles is “not about civil rights” or “the great issues of equality” but “the brutality of a mob, pure and simple.” He said he would “use whatever force necessary” to restore order.
That rioting had come after four white Los Angeles police officers who were caught on video beating black motorist King on March 3, 1991, were virtually exonerated by a jury. Bush said he, too, was “stunned” at the verdict, the paper reported.
In 1993, Stacey Koon and Laurence Powell, two of the four officers, were found guilty by a federal jury of violating King’s civil rights. They both served 30 months in prison and did not return to the police force. The other two officers, Timothy Wind and Theodore Briseno, were both fired by the LAPD.
With Post wires
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