Habitability Requires the Right Kind of Star

first_imgby Dr Henry RichterThis is a continuation of my discussion on the requirements to allow life to exist on a planet elsewhere in the universe. “Facing Reality about Life on Other Planets” (8/11/17) listed 20 features and characteristics, all of which would be required, for life to exist and flourish. That discussion began with the first characteristic: “a location in a ‘safe’ place in the galaxy, not close to any active regions, overactive stars, or black holes.” This chapter addresses the needed characteristics of the host star to which the planet under discussion is associated. It leads to a discussion of the planet’s orbital requirements as well.Sunrise a few hours before a total eclipse in Baja, July 11, 1991, by David Coppedge Star TypesIt’s pretty obvious that to have a planet with life, there needs to be a star. We know there are all sorts of stars in the universe. Stars are classified by their spectra – the light they give off, and the portions of light that are absorbed by the elements in the star’s atmosphere, and their temperature. The star is the source of heat for the planets in their system, and therefore for a planet to have a livable temperature, the star’s characteristics and the planet’s position with relation to the star needs to be just right. The temperature of the planet-candidate is very crucial to life. Since life as we know it is water–based, the star’s temperature affects the water greatly. The livable temperature has to be in a rather narrow range – look at all the hysteria about global warming and the effect of just a few degrees’ variation.The star needs to be within a fairly narrow range of: size, heat output, stability, and spectral composition. Stars are classified into seven main types. In order of decreasing temperature (and luminosity): O, B, A, F, G, K, and M. The temperatures are:O – over 25,000 KB – 11,000- 25,000 KA – 7,500-11,000 KF – 6,500 -7,500 KG – 5,000-6,000KK – 3,500-5000 KM – under 3,400 KSo you see there is really a wide variety of star types, most of which are unsuitable to heat a planet to a livable temperature. Habitable zones are just not possible with most. Our G2 yellow dwarf is really the only possibility. And, how many of these are there? It is estimated that in the billion galaxies with a billion stars each, that there are about 1022 stars in the known universe. That’s 1 followed by 22 zeros. That is more stars in the universe than there are grains of sand on earth – deserts, shorelines, and elsewhere. Estimates are that only one in 10,000 is a G2 yellow dwarf, but that is still a lot of stars that can host planets on which life conditions are possible. Present estimates are that there are maybe 512 G2 stars within 100 light years of us, and these are the ones most easily examined for planets. But more about that in a later writing.Image credit: Illustra MediaOur sun with a surface temperature of about 5,500 degrees Celsius and the radiating size it is puts out the right amount of heat to produce a habitable zone for a reasonable orbit, which is where our earth travels. The sun emits radiation over the whole electromagnetic spectrum of gamma rays, x-rays, ultraviolet, visible, infrared, microwave, and radio waves. The shorter wavelengths (gamma, x-ray, and ultraviolet) are ionizing in nature and are destructive to chemical and life structures. As we will see later, these do not reach the earth’s surface in any quantity. Visible light is what we see with and which is used in photosynthesis. It also provides some heat, as does the non-visible infrared rays.The mass of the sun causes gravity which keeps the earth in its orbit around the sun. Let’s consider the earth’s orbit, at about 93,000,000 miles around the sun. It is at that distance that the proper heat balance is achieved giving us a livable climate. The orbit is nearly circular which is very important to maintain a uniform temperature. If the planets orbit deviated much from circular, when closer to the sun,  it would get warmer, and when further away, cooler. That would result in major climate changes each orbit which would not be good for living things. Calculations show that if the earth were 5% closer to the sun, the surface temperature would reach several hundred degrees. If it were 5% further away the earth would be perpetually frozen. So each feature of the existence of the earth as it flies through space turns out to be crucially important to the existence of life.As the earth spins on its axis, it creates a night-to-day cycle over its surface. The length of each day and night needs to be such that the cycle could be tolerated by living things. Twenty four hours seems ideal for activity and then rest. Imagine if each day and night were one hour long due to a fast spin, which would make a brutal cycle. If each day and night were even 100 hours long, that would require long integration times between activity and rest. Some planets have a rotation that is locked to the orbital period so one side always faces the sun (like one side of the moon always faces the earth). That would be an impossible situation with one side always hot, and the other at the frigid temperature of space. So, again we have the optimum situation for our planet.The axis of the earth is inclined about 23 degrees from the orbital plane. This is another important fact. As the earth moves around the sun over the course of a year, half of the time the northern region is inclined to the sun and the other half year inclined away, making seasons occur. One thing this temperature difference does is to create some circulation of the atmosphere and the oceans. I do not imagine that seasons are crucial to life, but they are sure convenient for agriculture and living an interesting life, so they seem to be for our welfare. We are fortunate that much of our environment is not just for our existence and survival, but to make our living easier.One other feature of the solar system is the existence of gas giant planets beyond our earth orbit: an unusual arrangement for the exoplanets found around other stars, many of which have gas giants closer to their stars than Mercury is to the sun. In our solar system, the outer gas giants, particularly Jupiter, serve a function of attracting and absorbing much of the debris and junk flying around which would be injurious to life if they impacted the earth. Who knows of all that goes on around us that protects us from things unknown?In the next article, we will examine other requirements for habitability.Dr Henry Richter, a contributor 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 458 times, 1 visits today)FacebookTwitterPinterestSave分享0last_img read more

Griezmann Tells Atletico Madrid He is Leaving the Club

first_imgMADRID — Antoine Griezmann is leaving Atletico Madrid and could be close to joining Barcelona next season.The France forward told Atletico on Tuesday he has decided not to stay for a sixth season with the club.He said in a video released by the Spanish club that he wants to “see different things, face other challenges.”“It wasn’t easy to make this decision, but it’s what I feel and what I need,” the 28-year-old Griezmann said. “I want to thank everyone for their support during these five years with the club where I’ve won my first important trophies. I’ve enjoyed some incredible moments and I’ll never forget them.”Griezmann joined from Real Sociedad in 2014 and helped Atletico win last year’s Europa League title, alone with one Spanish Super Cup and a UEFA Super Cup“I’ve truly enjoyed my time with the club,” he said. “I’ve always left everything on the pitch, always tried to make fans happy.”Griezmann did not give any hints about his future but he has been widely linked with a move to Barcelona, with some Spanish media saying he has already reached a deal with the Catalan club.Barcelona has acknowledged being interested in Griezmann, and the player once confirmed there was an offer made by the club.There has been speculation about his move to the Catalan club during the most recent transfer windows. Last June, Griezmann announced his decision to stay with Atletico at the end of a 45-minute television special called “The Decision.”Griezmann had a contract with Atletico until 2023 with a reported buyout clause of 200 million euros ($224 million), but the clause will be automatically reduced to about 120 million euros ($134 million) this summer.Griezmann was a World Cup champion with France last year, when he also finished third in the Ballon d’Or vote for world’s best player, behind Luka Modric and Cristiano Ronaldo.Atletico coach Diego Simeone, who recently said he didn’t think Griezmann would leave, is also losing captain Diego Godin for next season. The Uruguay defender said he was not able to reach a deal to extend his contract with the club.Atletico’s final match of the season is Sunday at Levante. It finished second to Barcelona in the Spanish league for a second straight season.By: Tales Azzoni, AP Sports WriterTweetPinShare0 Shareslast_img read more

a month agoMan Utd release statement to assure supporters of club’s ambitions

first_imgTagsTransfersAbout the authorPaul VegasShare the loveHave your say Man Utd release statement to assure supporters of club’s ambitionsby Paul Vegasa month agoSend to a friendShare the loveManchester United have released a statement to assure supporters of the club’s ambitions.In a statement issued to a fans’ forum earlier this month, United sought to assure supporters that on-field success comes before commercial deals for them.A United statement read: “Everyone at the club, from the owners down, is focused on competing for and winning trophies at the highest level. “To do that we have invested heavily in the playing squad and will continue to do so.”At the same time, the exciting pool of talent coming through from our youth and academy sections is a result of increased investment in this area over the last five years. It’s important to note that while our successful commercial operation helps drive that investment, the priority is the focus on achieving success on the pitch.”Similarly, it is worth noting that we are not looking at or buying players based on their commercial appeal. We agree that recruitment is critical. We are committed to getting this right and there has been huge investment in this area to put our recruitment department into a position to be able to deliver the manager the players he wants. This process is significantly more effective than four or five years ago.” last_img read more

Foreign investors pull out Rs 38930 cr in 201819 Sebi annual report

first_imgNew Delhi: As macroeconomic headwinds weighed on investor sentiments through the year, foreign portfolio investors pulled out Rs 38,930 crore in 2018-19, according to market regulator Sebi’s annual report. “In order to further develop the Indian securities market as an avenue for fundraising, eligibility norms for FPIs (Foreign Portfolio Investors) were relaxed and data privacy concerns of FPIs were addressed,” the 2018-19 annual report said. Among other steps, the watchdog had withdrawn the minimum residual maturity restriction of three years for investment in government securities and state development loans. Also Read – Thermal coal import may surpass 200 MT this fiscalBesides, sub-categories under the category of corporate bonds were discontinued resulting in a single limit for FPI investment in all types of corporate bonds, as per the report. The limit for FPI investment in debt was revised from Rs 6.49 lakh crore to over Rs 6.98 lakh crore for the April 2019-September 2019 and more than Rs 7.46 lakh crore for October 2019-March 2020, it noted. To address concerns over data privacy, a provision similar to One Time Password (OTP) was introduced, wherein, an intermediary can access information related to beneficial owner, including senior managing official of an FPI only after confirmation from the FPI or its global custodian. Additionally, measures like relaxation of eligibility norms for FPIs, monitoring of foreign investment limits, easing the process of on-boarding of FPIs were taken.last_img read more

Canadas trade deficit shrinks in July surplus with US highest since October

first_imgOTTAWA – Canada’s merchandise trade deficit with the world shrank to $114 million in July, the smallest since a surplus in December 2016, as its trade surplus with the United States grew to the biggest in a decade, Statistics Canada reported Wednesday.The federal agency reported that merchandise exports to the United States rose 3.3 per cent in July to $38.4 billion, while imports of American goods edged down 0.1 per cent to $33.1 billion in July.As a result, Canada’s merchandise trade surplus with the United States widened to $5.3 billion in July, from $4.1 billion in June — the biggest monthly trade surplus with its largest trading partner since October 2008.Canada’s surplus with the United States was offset by a $5.5 billion trade deficit with other countries, up from $4.8 billion in June.The total value of Canada’s exports to all countries rose 0.8 per cent to a record $51.3 billion, mainly because of higher crude oil prices, while the value of imports from all countries declined 0.4 per cent to $51.4 billion due to fewer aircraft imports, Statistics Canada said.The overall trade deficit in July was down from $743 million in June, a figure that was revised from $626 million in the previous report.Several analysts said they had expected July’s trade deficit would rise to about $1 billion and noted trade volumes reported by Statistics Canada on Wednesday were down overall — with exports falling 0.8 per cent and imports dropping 1.1 per cent.They attributed a majority of the positive gains to higher energy prices.“Overall, the rise in export prices masks what was actually a disappointing month for outbound shipments. Moreover, oil prices have since levelled off and other commodity prices have also softened,” CIBC economist Royce Mendes wrote in a commentary.“In spite of the narrower deficit, there’s little reason then, to change our call for growth to slow in the third quarter.”A short time after the Statistics Canada report, the central bank announced its key interest rate will remain unchanged at 1.5 per cent, where it has been since July 11. Many economists have said the rate will likely be increased in October.The trade report came as Canadian and American negotiators resumed talks in Washington, D.C., following a four-day break from last week’s intense efforts to reach agreement on revising the North American Free Trade Agreement.President Donald Trump has claimed that the United States needs to eliminate large trade deficits with Canada but a report from the U.S. Trade Representative says a 2017 deficit in goods (US$17.1 billion) was outweighed by a US$25 billion surplus in services sold to Canada.Statistics Canada noted that July was the first month that Canada charged retaliatory tariffs on imported American steel and aluminum and the second month of U.S. tariffs on Canadian steel and aluminum.The agency said that, on a seasonally adjusted basis, there was a 16.4 per cent increase in Canadian exports of steel subject to the U.S. duty imposed by President Donald Trump, following a 36.3 per cent decline in June.Exports of Canadian aluminum subject to Trump’s tariffs were down 2.0 per cent in July, on top of a 4.7 per cent decline in June.Canada’s imports of U.S. steel products subject to a 25 per cent tariff fell 39.6 per cent in July, on a seasonally adjusted basis, following a 32.7 per cent increase in June.Canada’s imports of U.S. aluminum that are subject to a 10 per cent retaliatory tariff were down 5.2 per cent and imports of other U.S. products subject to the 10 per cent tariff fell 22 per cent in July.RBC economist Nathan Janzen noted that monthly data is volatile so a few months doesn’t make a trend “and risks around Canada’s trade relationship with the U.S. remain.”“It could also be, though, that Canadian exports are finally starting to get at least a modest lift from stronger global trade flows and an improved U.S. industrial sector.”— by David Paddon in Torontolast_img read more

Moonves scandal looms over CBS shareholder meeting

first_imgNEW YORK — The investigation into sexual-misconduct claims against former CBS CEO Les Moonves will loom over the network’s annual shareholder meeting on Tuesday.But no major decisions are expected right away. A newly revamped board will have to decide by the end of January whether Moonves receives a $120 million severance package. It will also have to chart the path for CBS to recover from the scandal.Moonves was ousted in September after The New Yorker published allegations from 12 women who said he subjected them to mistreatment. The network launched an investigation with two outside law firms.Shareholders will vote to elect 11 board members, six of whom came aboard in a reshuffling after the scandal broke.The Associated Presslast_img read more

Samsons 2nd IPL ton powers RR to 1982

first_imgHyderabad: Sanju Samson smashed the first century of the ongoing Indian Premier League and together with skipper Ajinkya Rahane stitched a century stand to guide Rajasthan Royals to a mammoth 198 for two against Sunrisers Hyderabad here on Friday. Samson didn’t spare a single Sunrisers’ bowler and remained unbeaten on 102 that came off just 55 balls with the help of 10 fours and four hits over the fence. It was Samson’s second IPL ton. His first century in the T20 tournament came in 2017. Also Read – Puducherry on top after 8-wkt win over ChandigarhOpening the batting after winning the toss, Rahane led from the front with 49-ball 70 and together with Samson shared 119 runs for the second wicket to set the base for the total after the early dismissal of Jos Buttler. Introduced into the attack in the fourth over, Rashid Khan (1/24) struck with only his second ball, cleaning up dangerman Buttler around his legs. Rajasthan’s decision to bat first didn’t go according to plan, at least, in the powerplay as the visitors struggled against Sunrisers’ disciplined bowling to garner just 35 runs in the first six overs. Also Read – Vijender’s next fight on Nov 22, opponent to be announced laterAfter Buttler’s dismissal, skipper Rahane was joined at the crease by Samson and the duo played cautiously without taking any undue risk to take Rajasthan forward. While Rahane played the anchor’s role, Samson opened up his arms soon and smashed two sixes in consecutive overs of Shabaz Nadeem and Siddharth Kaul to give some momentum to Rajasthan’s innings. Rahane soon joined his junior colleague and clobbered Nadeem straight over his head as Rajasthan reached 75 for one at the halfway stage. After a slow start, Rahane stepped on the accelerator and welcomed Vijay Shankar with six over deep square leg boundary. Both Rahane and Samson paced their innings to perfection, as after playing cautiously initially, they broke their shackles when needed and notched up the team’s 100 in 11.5 overs. Rahane registered his first fifty of the ongoing IPL in 38 balls while Samson brought up his half-century in 34 deliveries as the duo raised 100-run stand for the second wicket in 65 balls. Rahane finally departed in the 16th over bowled by Nadeem, holed out by Manish Pandey at long-on as he went for a big shot. He struck four boundaries and three sixes during his knock. Bhuvneshwar Kumar’s torrid time at the death overs continued. If it was Andre Russell in the last match, it was Samson Friday as the young Kerala batsman too the senior pacer to cleaners, hitting him for four boundaries and one six to pick up 24 runs from the 18th over. As if that was not enough, Bhuvneshwar witnessed yet another forgettable day as he leaked 21 runs in the last over. Brief scores: Rajasthan Royals 198/2 (Sanju Samson 102 not out, Ajinkya Rahane 70) vs Sunrisers Hyderabad.last_img read more

Mercury rising in Delhi thunderstorms likely later

first_imgNew Delhi: It was a sunny morning in the national capital on Saturday with the maximum temperature expected to hover around 39 degrees Celsius, with thunderstorms and squalls expected in the later part of the day. The minimum temperature was recorded at 22.4 degrees Celsius, three notches above the season’s average. “The sky was clear in morning. Thunderstorm with squall is likely to take place,” an Indian Meteorological Department official said. At 8.30 a.m. the humidity was recorded at 58 per cent. On Friday, the maximum temperature was recorded at 39.3 degrees Celsius, five notches above the season’s average, while the minimum was season’s average at 20 degrees Celsius.last_img read more

Tribunal serves notice to JeI asks why it cant be declared unlawful

first_imgSrinagar: The Unlawful Activities (Prevention) Tribunal, constituted by the Centre, has issued a show cause notice to Jamaat-e-Islami Jammu Kashmir (JeI), which was banned by the government in February, asking it why the organisation cannot be declared as an unlawful association.”A notice is hereby given under sub-section (2) of Section 4 of the Act (Unlawful Activities Prevention Act) and you are hereby called upon to show cause, within 30 days from the date of service of this notice, as to why your Association, declared as unlawful, be not adjudicated to be so and why an order confirming such declaration be not made under Section 4(3) of the Act,” said the notice issued by Registrar, Unlawful Activities (Prevention) Tribunal, Lorren Bamniyal, to the JeI. The notice was issued on April 5. The Tribunal asked the Jamaat to file objections or reply affidavits, if any, before the next date of hearing of the Tribunal at the office of the Registrar. “In case the objections/reply and the documents are in regional language, true English translation thereof be also attached. You may appear through a duly authorised person before the Tribunal on 20 May, 2019 at 3 PM in Court Room number 26 for further proceedings,” the notice said. The Centre had constituted the tribunal headed by a Delhi High Court judge to decide whether there is sufficient cause for declaring the JeI as an unlawful association. The Ministry of Home Affairs on March 23 had issued a notification which states that Justice Mukta Gupta would head the tribunal set up under the Unlawful Activities (Prevention) Act (UAPA). The government in its February 28 notification had banned the JeI, saying it was of the opinion that the Jamaat is “in close touch with militant outfits” and is supporting extremism and militancy in Jammu and Kashmir and elsewhere. It said the outfit claims “secession of a part of the Indian territory from the Union” and supporting terrorist and separatist groups fighting for this purpose. The action came following the February 14 terrorist attack in Pulwama that killed 40 CRPF personnel.last_img read more

Ohio State athletic director Gene Smith uninterested in paying players

OSU vice president and athletic director Gene Smith in an interview with The Lantern Jan. 29.Credit: Lantern file photoWhile Gene Smith supports covering all college costs and promising four-year scholarships, he doesn’t think student-athletes should be paid.“I am not a proponent of creating an employer-employee relationship, which changes the whole dynamic,” the Ohio State vice president and athletic director said in a July 7 interview with The Lantern. “At the end of the day, you get fired if you don’t perform if you’re an employee, and we don’t want that.”Smith said he hopes the NCAA never makes it to the point of paying student-athletes beyond the cost of attendance, and added that if it did, it could lead to less lucrative sports being cut.“I hope that we don’t get to that point,” he said. “If we do, then the men’s volleyball teams of the world, and the gymnastics teams, and all those teams — sayonara.”But rather than a salary, Smith said he is strongly in favor of covering the cost of attendance beyond just tuition for student-athletes, something the Big Ten is pushing for as well.He also said there are athletes who might not have saved up for college but who later find themselves in a position to attend school because of their athleticism.“They may have aspired to just go work in the Ford plant, and all of a sudden they become this great athlete and they’re coming from families where the families didn’t develop a war chest to support them to go to school,” he said. “So those miscellaneous expenses aren’t paid for.”Smith added the scholarship plan in place today is “old and inadequate” and needs to be changed.In a June 24 press release, the Big Ten presidents and chancellors said they want to increase their efforts toward schools covering “the full cost of a college education, as defined by the federal government.”Like Smith, the Big Ten statement acknowledged paying football and basketball players –– the sports that bring in by far the most money –– would hurt other, smaller programs.The release also touched on an intent to guarantee four-year scholarships whether the player continues to compete throughout his or her time at the university. The same would still apply if the student-athlete chose to turn pro before completing their degree.Smith said OSU already guarantees scholarships through degree completion. He added that it should be required across the board.“What the Big Ten is talking about, and what’s being talked about nationally, is that should be mandated for all schools to do that,” he said.Smith said he was at former OSU basketball player Mike Conley Jr.’s wedding recently when he started talking to Greg Oden, another former OSU basketball player who has moved into an NBA career, about what he plans to do next.“He’s unsure, but there’s a possibility he might come back and even though he’s a multi-millionaire, we’ll probably end up paying for his degree,” Smith said.While Smith and the Big Ten are pushing to cover the full cost of attendance and to guarantee scholarships, player compensation has been a hot debate around the entire NCAA recently after athletes at Northwestern University made attempts to unionize.A National Labor Relations Board ruled in March that football players at the university can qualify as employees and can therefore unionize. The players haven’t taken any steps to do so yet, however, and Northwestern filed a brief with the NLRB earlier this month detailing its opposition to its players unionizing. read more