SALT LAKE CITY — On the final leg of the longest trip so far of the season, with a whittled down roster and looking up at a 20-point deficit at the start of the fourth quarter, the Warriors had every reason to concede defeat.The Warriors (3-14) concluded a four-game trip with a 113-110 loss to the Utah Jazz on Friday at Vivint Smart Home Arena, but will return to the Bay Area with a spark provided by a late rally and exciting ending.With only eight players available, Warriors coach Steve …
by Dr Henry RichterMy past few articles on “Facing Reality About Life on Other Planets” have dealt with the necessary conditions for the existence of life on a planet—any planet. With the almost fanatical drive of the scientific community to find and prove the existence of life elsewhere in the universe, it is important to ponder the requirements for habitability. We’ve looked at the location in a galaxy, the location in a stellar system, the type of star required, and the physical characteristics of an exoplanet such as mass, rotation rate, atmosphere, magnetic field, water, a partial rocky surface and so on. This final article will consider the composition of planet: what materials and chemical building blocks must be present to sustain life.CarbonWe talked about life being based on carbon chemistry. A readily accessible and usable supply of carbon must be available in the planet’s chemical composition. Carbon itself, with its four bonds, is a remarkable element having a flexible bonding capability, giving it hundreds of thousands of possible molecular structures. The only other close element is silicon which can form a few somewhat complex molecules, but only a few compounds—nowhere near as many as carbon. Star Trek fantasies aside, astrobiologists generally admit that silicon-based life is just not possible. Carbon is known to be the basis of the acids, bases, enzymes, proteins, alcohols, esters, ethers, amino acids, and much more. A large number and variety of these are involved in building and maintaining living cells. So a ready supply of carbon is necessary. Where can it come from?The earth has usable carbon available in the atmosphere in the form of carbon dioxide gas, in carbonate rocks, as carbon dioxide dissolved in the oceans and lakes, and secondarily in plant tissues and juices (converted from atmospheric carbon dioxide). Both plants and animals are involved in the earth’s carbon cycle. Plants convert carbon dioxide gas into a wide variety of carbon compounds. These plants are consumed by animals, used as fuel, and the metabolic product being carbon dioxide. It’s a remarkable process!Other ElementsMany other elements are required for life in addition to carbon. These probably can’t be ranked in order of importance since all are essential. The next that comes to mind is calcium. This is used in bones and structural frameworks, and is an important signaling molecule. Calcium is also important in eggshells and seashells. Nitrogen is another essential element. Nitrogen compounds are needed for plant growth, and are in proteins. Phosphorus plays an important role in cell structure, cell activity, and the genetic code molecules, DNA and RNA. A variety of other elements, even some rare earths, are involved in life’s structures and processes. All you have to do is look at the label of a bottle of mineral supplements in a health food store to find selenium, magnesium, copper, and several others. We even see non-minerals such as iodine and bromine. Could we exist if any of these were absent from the earth, or weren’t readily accessible? I don’t know, but it raises the question whether complex life could exist elsewhere if any of these—or some combination of these elements—were missing. That brings us to the consideration of probability: what is the chance that all the required factors would exist simultaneously on an alien world?Probability: Running the NumbersLet’s look at the big picture now – the really big picture: the universe. It is estimated that there 100 billion galaxies (1011), each with 100 billion stars. That results in 1022 stars. Say that only one in 10,000 is a dwarf main sequence G2 star which, as we saw, is the most stable star for a habitable zone. That leaves 1018 possible host stars. That’s a quintillion—still a lot of stars! Let’s say that only one of 10,000 of these stars has a planet in the habitable zone; that now gives us 1014 candidate planets (a hundred trillion). Let’s further grant a generous 10% chance that any of the required features would “happen” to be present in any one planet (I think a 1% chance would even be high). All of these features have to be present simultaneously for there to be any chance of complex life existing. The factors below are listed in the documentary The Privileged Planet, mentioned earlier.Located within the galaxy habitable zone 10%A stable star with constant energy output 10%A planet formed within the habitable zone around the star 10%A planet in a stable orbit maintaining a steady distance from the star 10%Protected by gas giant planets in the solar system 10%A rotation speed of about 24 hours 10%A planet with a suitable atmosphere: oxygen-rich, depth, circulation 10%A planet with the appropriate mass 10%A planet with abundant water 10%A reasonable ratio of water to land mass 10%A crust capable of plate tectonics 10%A magnetic field within the proper strength range 10%A moon of the proper size, distance, and orbit around the planet 10%A readily available source of abundant carbon compounds 10%Trace elements of the right type and quantity 10%One could go on and on, adding more factors, but these are a few of the most essential features to consider. So let’s multiply that out: 0.1 × 0.1 × 0.1 × 0.1 × 0.1 × 0.1 × 0.1 × 0.1 × 0.1 × 0.1 × 0.1 × 0.1 × 0.1 × 0.1 × 0.1 = 10-15. This probability times 1014 candidate planets leaves 10-1 planets, less than one! If I had used a 1% probability instead of 10% (more reasonable), that would have reduced the overall probability to 10-30, yielding 10-16 habitable planets out of the hundred trillion candidate planets. This implies that even one habitable planet in the whole universe has less than one quadrillionth a chance of being found! With a probability this small, changing the order of magnitude of our estimates for the number of stars is not going to make much difference.Beyond just the requirements for habitability, could we expect undirected evolution to bring about a second form of complex life anything like the beauty and complexity of life we find here on Spacecraft Earth? Could life even start by chance, before evolution’s natural selection comes into play? I maintain that it could not have happened once by accidental means here, much less than a second time elsewhere!So, to wrap up, the outlook is bad for avid hunters of populated planets. There aren’t likely to be any other habitable planets in the universe. The only reasonable conclusion, given the evidence we have considered, is that our earth was specially and wonderfully made to be inhabited.Dr Henry Richter, a contributing science writer to Creation-Evolution Headlines, was a key player at NASA/JPL in the early days of the American space program. With a PhD in Chemistry, Physics and Electrical Engineering from Caltech), Dr Richter brings a perspective about science with the wisdom of years of personal involvement. His book America’s Leap Into Space: My Time at JPL and the First Explorer Satellites (2015), chronicles the beginnings of the space program based on his own records and careful research into rare NASA documents, providing unequaled glimpses into events and personnel in the early days of rocketry that only an insider can give. His next book, Spacecraft Earth: A Guide for Passengers, is due out later in 2017. For more about Dr Richter, see his Author Profile.(Visited 448 times, 1 visits today)FacebookTwitterPinterestSave分享0
Airbus CEO Tom Enders. Photo: Steve Creedy. The A380 superjumbo is not dead, it’s just resting.That was the message from Airbus and one of its major customers in Toulouse on Friday as speculation continues about the superjumbo’s future.Airbus announced earlier this year that it will more than halve production of the superjumbo from the current 2.5 per month to one a month because of lacklustre demand.But Airbus chief executive Tom Enders, speaking at an event to celebrate the manufacturer’s 10,000th aircraft delivery, predicted there would still be a demand for the A380 into the future.Read: The world needs more A380s“We’ve pulled down the rates for some time but we are very confident we will produce an aircraft for many years to come,’’ he said.Enders said Airbus was continuously making small improvements to the A380.“And we’ve said many times that bigger improvements such as the famous re-engining is not so much a question of if, but of when,’’ he said.The manufacturer’s head salesman, John Leahy, said the A380 continued to generate passenger interest around the world.“People go out of their way to fly on the A380,’’ he said, adding that 10 per cent of passengers using London Heathrow Airport this year would be getting on or off one of the superjumbos.Singapore Airlines chief executive Goh Choon Phong said he continued to see a role for the double-decker aircraft his airline helped launch flying on high demand, high density routes where there were slot constraints.“So we will continue to see demand for such aircraft types,’’ he said.The Singaporean carrier is acquiring five new A380s but created waves for Airbus when it decided not to renew the 10-year lease on its first Airbus A380. The announcement came as Malaysia Airlines revealed it was in discussions with airlines in the region about offloading its fleet of six A380s.SIA may also not renew four more leases due to end, although Goh reiterated that a decision on that had yet to be made.The Singaporean carrier has also said it will launch new cabin products with the arrival in the second half of next year of the first new A380.Goh said the new products, developed over “the last few years’, would wow customers and would ensure that the airline retained an industry-leading position on products.
This article is only available to GBA Prime Members Sign up for a free trial and get instant access to this article as well as GBA’s complete library of premium articles and construction details. Though he landed his first job in architecture while still in high school, architect Jeff Adams’s path to designing high-performance homes wasn’t a straight line.When his father encouraged him to get a summer job as a teenager, Jeff sent resumes to a dozen architecture firms. One of them, Line and Space, a modern architecture firm in Tucson, AZ, run by an acquaintance of his father, offered Jeff a job. At first the work was maintenance on rental properties, but eventually Jeff learned to trace sketches for presentations and to building architectural models.After high school, Jeff studied civil engineering at Princeton, though he did his thesis on architecture and earned an architecture certificate. He then went back to work for Line and Space. They we building a 25,000 square foot home. “It was sort of over-the-top,” said Jeff, “but it also was kind of fun. I worked on site, drawing a lot of details in the field. It was an immersion into modern detailing.”Soon, Jeff returned to school for a master’s degree in architecture, this time at UCLA. He stayed in southern California where he was a project architect at Johnston Marklee and worked on the acclaimed Hill House. But Jeff eventually had enough of the big city. When a friend recruited him to work on a communal property in northern California, he jumped on the opportunity. The move turned out to be the start of an eight-year sabbatical from conventional architecture.After falling in love, getting married, and having a child, Jeff realized that he had “unfinished business with architecture.” He dusted off his textbooks and studied for the state exams. He passed. He finally had a license to practice architecture. Through a mutual friend, Jeff was introduced to Mela Breen, the founder and principal… Start Free Trial Already a member? Log in
A day after intense showers ravaged several parts of Pune district, Guardian Minister Chandrakant Patil faced the ire of citizens on Friday, even as the death toll across the district rose to 18.Speaking here after surveying the worst-hit spots in the city and the district, Mr. Patil blamed illegal constructions and encroachments for the flash deluge that resulted in massive damage to property and loss of life.“Illegal constructions and encroachments on various canals have diverted the natural flow of streams, which led to water entering residential societies and wrecking property. The causes for these constructions have to be investigated. Moreover, why weren’t basic security measures followed at the time of these constructions?” Mr. Patil asked. Team to probe disasterHe said a team comprising senior IAS officials would be constituted to investigate the disaster. He also said all relief measures for the rain-affected in Pune would be applicable under the government resolution (GR) issued at the time of the Kolhapur and Sangli floods.On Thursday, when the city was coping with the rain damage, the Guardian Minister was in Delhi to iron out the seat-sharing issues between the Bharatiya Janata Party and the Shiv Sena for the elections.Earlier, irate protesters blocked Mr. Patil’s convoy near Tangewala Society in Aranyeshwar area, prompting him and his entourage to leave the spot after barely 15 minutes. Five people died after the society’s compound wall collapsed owing to the relentless downpour. Protesters demanded to know what Mr. Patil was doing in Delhi when the city was being battered by flash floods.Urging him to go back, they said the Guardian Minister’s belated visit was merely a photo opportunity.Mr. Patil said those heckling him were mere “troublemakers” hired by the opposition parties. “There were no problems whatsoever. I was [at Tangewala Society] for 20-25 minutes. Genuine citizens told me about their problems. The rest were troublemakers hired by opposition parties.” He said because the model code of conduct is in place for the Assembly elections, he was compelled to put things before the aggrieved citizens in a restrained manner.Toll up to 18Meanwhile, the death toll across the district rose to 18 with at least four people still missing. There were unconfirmed reports of two more bodies being recovered, indicating a likely rise in the number of the deaths.More than 3,000 people in the city are lodged in transit camps, while teams of the fire department and nearly 2,000 municipal workers carried out cleanliness drives and relief operations.Despite the India Meteorological Department’s (IMD) warnings of likely heavy rain on the intervening night of Thursday and Friday, the weather remained calm throughout the better part of Friday. Schools and colleges across the city and four other tehsils of the district remained shut following a precautionary directive of the Pune District Collector.According to a release issued on Friday afternoon, the IMD has forecast light to moderate rain on Friday night to be followed by light rain over the weekend.