Is the Universe finite or infinite?

How large is the Universe? How do we measure its size? How can we even think of measuring something that is believed to be boundless? The enormity of the Universe may be beyond our comprehension, but measuring its size is not. Our measuring sticks are the cosmic microwave background radiation (CMBR) which is relic of the super hot Big Bang radiation cooled down to three Kelvin (-270 degrees Centigrade) with wavelength in the microwave region and cosmological red-shift, increase in the observed wavelength of electromagnetic waves from a receding source.
The size depends on the distinction between “visible” and “observable” Universe. Although there is no general consensus among astronomers about the actual size, one thing they agree on for sure is how far away we can see.
We can argue that if the age of the Universe is 13.7 billion years (see “Universe in age crisis!” TDS July 10, 2012) and since light travels with a finite speed, we can't see anything beyond 13.7 billion light years. (One light year is about six trillion miles.) In reality, we can see lights that were emitted only after the decoupling epoch, a time around 380,000 years after the Big Bang, when radiation broke free from matter and could travel through space unimpeded.
The maximum distance light can travel since the birth of the Universe defines the “cosmic horizon.” Astronomers use the distance to the horizon as the radius of the visible Universe with Earth at the center. It is also known as the Hubble Length and is 13.7 billion light years. But is it really the size of the Universe?
Calculating the size of the Universe is a little tricky. Let us start with the premise that Big Bang is the correct theory of the origin of the Universe. The theory posits that the Universe, born out of a tremendous explosion from an infinitesimally small volume, is undergoing expansion at a rapid rate. It was, however, an explosion of space; not an explosion into space. Consequently, the Universe does not have an "edge" where space just runs out. Hence the cosmic horizon is a boundary in time, not in space. It still lies at the beginning of time - the moment of Big Bang. It exists because we cannot see back to a time before the Universe was born.
As the Universe is expanding at high speed in all directions, the most distant objects we can see were once much closer to us. The recession speed of stellar objects, according to Edwin Hubble, is directly proportional to their distance from us. He also noted from cosmological red shift that farther a galaxy is from us, faster it is moving away from us.
Thus the cosmic horizon is continually expanding outward and the observable Universe is growing larger in radius with each passing second. This implies that since the birth of the Universe, distant stars and galaxies have been pushed away from us far beyond the distance of 13.7 billion light years. The observable Universe, therefore, is much bigger than the visible Universe. The radius of the observable Universe is also referred to as the “comoving distance” because it is increasing with time.
What then is the radius of the Universe today? The answer is given by our measuring sticks cum cosmic storytellers, red shift and CMBR. Without going into the nitty gritty of calculation, they tell us that because of accelerated expansion, it is 94 billion light years across putting the edge of the observable Universe 47 billion light years away from us. Whatever the size is, thanks to the inflationary Universe; it increased our observational power to the extent that we can see or have seen things that are now at least 47 billion light years away from us in all directions.
“Two things are infinite: the Universe and human stupidity; and I'm not sure about the Universe.” Albert Einstein.

Abul resigns, at last Letter submitted to PM; govt not confirming yet

Information and Communication Technology Minister Syed Abul Hossain has finally tendered his resignation to the prime minister, paving the way for the government to revive the financial arrangements with the World Bank for the Padma bridge project.
However, there was no official announcement about his resignation.
It could not be confirmed whether Abul resigned from the cabinet or the post only. Several sources close to him said he wished to remain in the cabinet as a minister without portfolio.
Abul's resignation came a day after the finance minister on Sunday said the government had been considering accepting the WB's fourth condition to persuade the global lender to review the cancellation of the Padma bridge loan.
The WB's fourth condition was that the government send on leave the public officials and former communications minister Abul Hossain, who were allegedly involved in corruption in the project.
Prime Minister Sheikh Hasina received Abul's resignation letter and kept it with her, said sources in the ruling Awami League.
Abul skipped yesterday's scheduled cabinet meeting. He did not even inform the cabinet that he would not attend the meeting. His absence drew the attention of many ministers.
Talking to journalists of several media houses over the phone yesterday, Abul said probe had been going on into corruption allegations over the Padma bridge project. And he was unwilling to continue his duties under the circumstances. His well-wishers also advised him not to remain in the post of a minister while the investigation was on.
“So, I have made a decision … I won't stay in office,” he told Bangla daily Prothom Alo. He, however, did not give any details about his resignation.
Abul said he would come out clean from the probe, as he had not been “involved in the corruption”.
He claimed the Anti-Corruption Commission, the WB or the Canadian police would not find his involvement, saying he had maintained transparency all along.
Abul believed his resignation had apparently removed the main barrier to constructing the bridge with the global lender's funding.
Though the WB gave several conditions for funding the project, Abul's exit from the cabinet was the key.
His resignation is likely to end the 10-month impasse between the government and the WB following the global lender's corruption allegations in the $2.97 billion project. The WB in September last year suspended its promised $1.2 billion funding for the country's biggest infrastructure project.
Construction of the 6.15 kilometre bridge became uncertain when the WB last month cancelled its loan agreement on the grounds that not all its conditions were met.
“He [Abul] should have resigned much earlier. He finally stepped down but the country paid a high price for that,” a minister said on condition of anonymity after the cabinet meeting.
A security guard at Abul's Gulshan residence said Abul left home in the morning in a car without flag.
Later, he met the prime minister and turned in his resignation, said a source close to Abul.
It was the second time he resigned as a minister. He was forced to resign as state minister for the LGRD ministry in August 1997 over a controversy for using a private passport instead of a diplomatic book.
Though there has been a strong public opinion against him for the last few months, Abul has kept protesting his innocence and refuted allegations of any irregularities in the Padma bridge project. He accused a section of the media of resorting to propaganda against him, saying it misled the WB to cancel the project's funding.
The government also showed reluctance to take any action against him, other than transferring him to the ICT ministry.
Earlier, in an open letter published in several dailies on Saturday, Abul gave hints that he could resign for the sake of the country and proper probe into the corruption allegations.
The ex-communications minister first came under fire ahead of the last year's Eid-ul-Fitr for failing to repair and maintain roads and highways in many parts of the country.
He was removed from the communications ministry and given the charge of ICT ministry on December 5 last year after the WB brought corruption allegations against him and suspended its loan.
Apart from the WB, Asian Development Bank, Japan International Cooperation Agency and Islamic Development Bank are co-financiers in the project. ADB committed to provide $615 million, Jica $400 million and IDB $140 million.
After the WB cancelled its loan agreement, the government decided to construct the bridge with its own resources. The government, however, said it would welcome any foreign investment in the project.

Decoded Dolphin's math skills

Dolphins could teach humans a thing or two about finding Nemo. The aquatic mammals may pinpoint prey hidden in bubbles by using mental math.
By adjusting the volume of sonar clicks, then processing the incoming echoes, dolphins might have solved a problem that still stymies man-made sonar: how to peer through frothy water. Using clicks that mimic an Atlantic bottlenose dolphin, scientists devised a system that weeds out sound clutter from underwater bubbles.
“It's really ingenious, actually,” says oceanographer Grant Deane of the Scripps Institution of Oceanography in La Jolla, Calif. “I think it's very clever work, and there are a number of significant applications for it.”
Using something like a fireman's hose, researchers shot bubbles into a huge water tank set underground. The bubbles cloaked a submerged target: a steel ball slightly smaller than a baseball. Then, the researchers sent out short bursts of sound the faux dolphin clicks underwater, collected the echoes, and processed the data mathematically to figure out the steel ball's location.

Obese children's hearts in danger

Severely obese children are putting their heart at danger even while they are still in primary school, according to a Dutch study.
Heart disease is normally associated with middle age, but the early warning signs were detected in children between the ages of two and 12.
Two-thirds of the 307 children studied had a least one early symptom such as high blood pressure.
The findings were presented in Archives of Disease in Childhood.
Obesity is a growing problem around the world with more people becoming obese and at a younger age.
Two-year-olds with a Body Mass Index, a measure of obesity, greater than 20.5 are classed as severely obese. By the age of 18, a BMI of 35 is a sign of severe obesity.
Researchers at the VU University Medical Centre in Amsterdam collected data from the Dutch Paediatric Surveillance Unit between 2005 and 2007.
They looked at warning signs of heart disease in the severely obese children.
"Remarkably, 62% of severely obese children under 12 years of age already had one or more cardiovascular risk factors," the study concluded.
More than half had high blood pressure, and there were also cases of low "good cholesterol" and high blood sugar, which can result in Type 2 diabetes.
The researchers said this "may lead to cardiovascular disease in young adulthood".
Doireann Maddock, a senior cardiac nurse with the British Heart Foundation, said: "Although it was a small study, the findings leave a bad taste in the mouth.
"It's a huge concern so many obese children were identified as already having at least one risk factor for heart disease, including high blood pressure, high blood glucose and problems with cholesterol levels.
"However, this is a problem that can be addressed by stopping young people becoming overweight and obese in the first place.
"Highlighting the importance of healthy eating and physical activity from an early age will help protect the heart health of future generations."

Sharper Look Solar Corona revealed

Source: Science Daily

These photos of the solar corona, or million-degree outer atmosphere, show the improvement in resolution offered by NASA's High Resolution Coronal Imager, or Hi-C (bottom), versus the Atmospheric Imaging Assembly on NASA's Solar Dynamics Observatory (top). Both images show a portion of the sun's surface roughly 85,000 by 50,000 miles in size. Hi-C launched on a sounding rocket on July 11, 2012 in a flight that lasted about 10 minutes. The representative-color images were made from observations of ultraviolet light at a wavelength of 19.3 nanometers (25 times shorter than the wavelength of visible light).

Guest Uavs! 'Invisible UFOs' fill skies

Why are all the good UFOs invisible?" one Gather.com user asked in response to the latest "invisible UFO" report posted to the site.
You might have thought a defining characteristic of a UFO would be visibility. But thanks to zealous alien hunters doggedly scanning the sky with night-vision cameras, a new class of flying objects that only emit infrared light has emerged from the darkness. Are they spies from the great beyond?
"Some people claim to see actual battles between UFOs up in the sky, using night-vision equipment," the ufologist Robert Sheaffer told Life's Little Mysteries. "Those devices magnify faint objects so much that the sky seems to be filled with invisible UFOs. In reality, of course, they are seeing owls, bats, moths, airplanes, satellites, etc." Night-vision optics trade low resolution for high sensitivity, he explained, so that points of light (such as distant satellites) spill out into circles that make the objects appear huge.
However, some of the invisible UFOs out there really are spies of a sort or whatever else you choose to call military drones. [7 Things Most Often Mistaken for UFOs]
Consider, for example, an invisible triangle UFO recently caught on camera by the Laredo Paranormal Research Society, a Texas group. In their footage, captured using an infrared-sensitive third-generation night-vision camera and posted to YouTube July 13, an object composed of three evenly spaced glowing orbs streaked southward across the field of view and disappeared behind the roof of a house.
According to LPRS founder Ismael Cuellar, the "infrared-cloaked" object could not be seen with the naked eye, and cruised silently. "[We] have ruled out birds, bugs, airplanes, helicopters, and even flying drones by comparing them side by side as a point of reference," Cuellar told Life's Little Mysteries. This seems to leave just one explanation: It's a cloaked alien spaceship.
Not so, according to Ben McGee, a geoscientist, aerospace consultant, UFO skeptic and lead field researcher on the National Geographic series "Chasing UFOs." In McGee's opinion, all the signs point to this object being a border patrol drone with infrared anti-collision or identification lights. Here's why he thinks so.

Did You Know? What is a gene?

In informal language, it is a unit of heredity that is transferred from a parent to offspring and is held to determine some characteristic of the "proteins coded directly by genes"In technical terms, it is a distinct sequence of nucleotides forming part of a chromosome.
Genes are the things that play an important role in determining physical traits how we look and lots of other stuff about us. They carry information that helps make you who you are: curly or straight hair, long or short legs, even how you might smile or laugh, are all passed through generations of your family in genes.?"

US gives Syria weapons warning

President Barack Obama has warned Syria's President Bashar al-Assad that his government will be held accountable if it uses chemical weapons.
He was speaking after Damascus said they would not be deployed inside Syria but would be against foreign attack.
UN Secretary General Ban Ki-moon said that any thought of using chemical weapons would be "reprehensible".
Fierce fighting has taken place in Aleppo, where rebels claim to have captured parts of the city.
There are also unconfirmed reports from activists in Homs that security forces are threatening to storm the city's central prison.
Chemical threat
The sharp international response came hours after Syrian foreign ministry spokesman Jihad Makdissi gave Damascus's first implicit acknowledgement that a chemical weapons stockpile existed.
The weapons were safely stored, he said, and Syria would never use them against its civilians but only "in case of external aggression". In an attempt to retain some doubt about his country's unconventional weapons arsenal he later tweeted "if they exist".
The US and Israel have expressed concern about the fate of Syria's arms, with Israeli PM Benyamin Netanyahu speaking of a "great threat" of weapons sites falling into the hands of Lebanon's Shia Islamist group Hezbollah, allied to President Assad.
The State Department in Washington said any possible use of such weapons would be "completely unacceptable".
"They will be held accountable by the international community and the US, should they make the tragic mistake of using those weapons," President Obama added.
The BBC's Kim Ghattas in Washington says US officials have refused to discuss details of any contingency planning surrounding Syria's chemical weapons but they have acknowledged that US Secretary of State Hillary Clinton discussed the issue on a visit to Israel last week.
Aleppo clashes
Syrian rebels said they had taken control of the Salah el-Din area of the country's most populous city, Aleppo, on Monday but fighting was continuing there and in other districts late into the evening.
A child was killed when rockets were fired at a market in the al-Bab area of the city, opposition activists said.
Unverified video showed jubilant rebel fighters capturing a tank in the Sakhour district and the BBC's Ian Pannell, on the outskirts of Aleppo, said he had seen hundreds of rebels moving towards the city.
In the capital, it was a different story as footage showed Syrian troops going from house to house searching for rebel fighters in areas of Damascus that had been recaptured from the opposition.
Civilians in the Qabun area of the city complained of not being able to leave their homes and government forces were said to have taken up positions in Midan, held earlier by rebels.
Explosions and fires have been reported from the jail in the central city of Homs, where unarmed policemen are said to have defected and prisoners have staged a sit-in. Government officials had earlier denied there had been a defection.
Meanwhile, the refugee crisis is escalating both inside and outside Syria.
An estimated 1.5 million people are homeless within the country, according to the Syrian Arab Red Crescent. Another 115,000 Syrians have fled to neighbouring countries.
On Sunday, the Syrian Observatory for Human Rights reported that at least 19,106 people had been killed since March 2011. The UN said in May that at least 10,000 people had been killed.
Syria blames the violence on foreign-backed "armed terrorist gangs".
In June, the Syrian government reported that 6,947 Syrians had died, including at least 3,211 civilians and 2,566 security forces personnel.

Tears, tributes

The first novel that Rouf Mohammad Muhith had read was Humayun Ahmed's “Himu”. He was a student of class VI and thereafter he read all the books by this stand-apart writer.
“You were my role model. I will remember you forever,” Muhith, now a first-year student of Birshreshtha Munshi Abdur Rouf College, wrote in the condolence book yesterday, after paying the last tribute to his favourite writer at the Central Shaheed Minar.
He said he used to go to the Ekushey Book Fair every year just to get a copy of Humayun Ahmed's new book. “His story telling is unique. Whatever he wrote came from his heart and touched me. I also like the characters he created,” added the teenager in an emotion-choked voice.
Asked if the demise of the prolific writer had discouraged him from reading, Muhith said, “No. When I was in class VII, I met him at a book fair and asked for an autograph. It was there that he advised me never to stop reading.”
Millions of youths like Muhith and their earlier generations are deeply fond of Humayun Ahmed. This writer helped a whole range of generations to get back to reading through more than 200 books of his, most of which have been bestsellers. He inspired people to love their culture, tradition and nature.
Thousands of people from all walks of life, especially youths, gathered at the Central Shaheed Minar yesterday to pay the final tribute to the illustrious writer. His collections of Himu and Misir Ali; films Nandito Norokay, Shankhaneel Karagar; and books Jochhona O Jananir Golpo, Brihonnola, 1971, Gouripur Junction, Megh Bolechhe Jabo Jabo, Pencil-a Anka Pori, Kothao Keu Nei are only a few among his most popular works.
“Humayun Ahmed inspired us to dream and love nature, trees and moonlight,” said Jafrin Rezwana, a Dhaka University (DU) student of history, adding, “Death is not his end. His characters such as Himu, Misir Ali, Shubhro and Rupa will keep inspiring us.”
Sushmita Biswas, another DU student, said she had been having trouble accepting the fact that a great novelist, dramatist and filmmaker like Humayun Ahmed had died a premature death. “Shall we get any new books from him at the next book fair? No…this means a huge vacuum has been created in Bangla literature,” she added.
Humayun Ahmed also brought a new dimension to Bangla drama. He was a playwright, director and lyricist. Television viewers once even brought out processions urging the writer not to kill one of his characters, “Baker Bhai”, in the serial Kothao Keu Nei in the 1990s.
Recalling his memories, actor Masum Aziz told The Daily Star that he had found no lack of qualities as a human being in Humayun Ahmed. Besides writing and directing, he knew magic and how to paint and act. Overall, Humayun Ahmed was a scientist, he added.
“He knew about people's tastes the best. His scripts for drama were superb. Anyone could act with his dialogues,” said Aziz, expressing his sorrow that the acting industry had lost a valuable asset.
Development activist Ranjan Karmaker said the youth of the early 1980s was not interested in reading. Writers and publishers of that time used to be afraid of printing a big number of copies of a book considering that only a handful of middle-aged people were the main buyers of books. Humayun Ahmed's books attracted the younger generation to the Bangla Academy and Ekushey Book Fair in the late 1980s and 1990s.
“There are even instances of five friends buying a single book of Humayun. Students save to buy his books. This is something commendable,” he said. He popularised Bangla folk songs, musical instruments and stories to a great extent.
“You can now see the youth of today singing folk songs. Humayun Ahmed played an important role in this regard,” said Ranjan Karmaker.
Film director Chashi Nazrul Islam said Humayun Ahmed had enriched the Bangladeshi film industry when it was in a great crisis. He also inspired people about the Liberation War and patriotism.
Shankhaneel Karagar, Aguner Poroshmoni, Srabon Megher Din, Dui Duari, Chondrokotha, Noi No. Bipod Shongket, Amar Achhe Jol, Nirontor, Priotomeshu, Daruchini Dweep, Shyamol Chhaya and Ghetuputro Komola are some of his best known films.
Actress and Awami League lawmaker Tarana Halim said a great man like Humayun Ahmed was no more, but the question remained whether any initiative would be there to fill the vacuum of the great people the country had lost.
“The writer wanted to set up a cancer hospital. We will try to make his dream come true,” she said.

Goodbye Humayun