Cosmic inflation no longer theory, now a fact

 

On March 17, the most important day for cosmology in over a decade, the Harvard-Smithsonian Centre for Astrophysics made an announcement that swept physicists off their feet. Scientists published the first pieces of evidence that a popular but untested theory called cosmic inflation is right. This has significant implications for the field of cosmology.

The results also highlight a deep connection between the theories of relativity and quantum mechanics. This has been the subject of a century-old quest in physics. Cosmic inflation was first hypothesized by American physicist Alan Guth. He was trying to answer the question why distant parts of the universe were similar even though they couldn’t have shared a common history. In 1980, he proposed a radical solution. He theorized that 10^-36 seconds after the Big Bang happened, all matter and radiation was uniformly packed into a volume the size of a proton.

By the time it was 10^-33 seconds old, its volume had increased by 10⁷⁸ times — a period called the inflationary epoch. After this event, the universe was almost as big as an orange, expanding to this day but at a slower pace. While this theory was poised to resolve many cosmological issues, it was difficult to prove. To get this far, scientists from the Centre used the BICEP2 telescope.

Through the South Pole’s dry atmosphere, BICEP (Background Imaging of Cosmic Extragalactic Polarization) 2 studies the 13.5 billion-year old residual energy of the Big Bang called the cosmic microwave background (CMB). This is a field of microwave radiation that permeates the universe. The CMB consists of electric (E) and magnetic (B) fields, called modes.

The B-mode patterns, in particular, have undergone some changes as the universe aged. It is susceptible to gravitational effects. For example, the E-mode can be twisted by the strong gravitational pulls of large galaxies into the B-mode.

However, scientists were looking for effects of what are called gravitational waves. These are waves of purely gravitational energy capable of stretching or squeezing the space-time continuum.

The inflationary epoch is thought to have set off gravitational waves rippling through the continuum. In the process, they etched their effects on the B-mode, visible today as a curling pattern in the magnetic field.

To find this, a team of radio-astronomers led by John Kovac from the Harvard-Smithsonian Centre for Astrophysics used the BICEP2 telescope from 2010 to 2012. It was equipped with a lens of aperture 26 cm, scanning an effective area of two to 10 times the width of the Moon.

Then, they used the different datasets they’d collected to subtract unwanted signals from one another until they were left with one that showed only the amount of curl. Prof. Kovac said in a statement, “Detecting this signal is one of the most important goals in cosmology today.”

The curl due to gravitational waves was confirmed with a statistical significance of 5.2 sigma — sufficient to claim evidence — but only in the part of the sky they mapped. The team has set a significance of 2.7 sigma for the rest of the sky, and future work will focus on strengthening this.

Scientists were also looking for a ratio called the tensor-to-scalar ratio. It denotes the amplitude of the gravitational waves. Its value has been found to be 0.20 plus or minus 0.05. Although theoretical predictions had pegged it between 0 and 0.3, scientists had expected it to be less than 0.2. The higher value means the ancient gravitational waves were more powerful than expected, and could explain why galaxies formed so rapidly after the inflation.

Now, astrophysicists from other observatories around the world will try to replicate BICEP2’s results.

It is notable that gravitational waves are a feature of the theories of relativity, and cosmic inflation is a feature of quantum mechanics. Thus, the BICEP2 results show that the two previously exclusive theories can be combined at a fundamental level. This throws open the door for physicists to explore a unified theory of nature in new light.

NASA searches for ideas to bring asteroids closer to earth

 

U.S. space agency NASA has announced a formal proposal worth $6 million for projects that would help robots and astronauts grab an asteroid from deep space and bring it closer to earth for further study.

In support of NASA’s Asteroid Redirect Mission — a key part of the agency’s stepping stone path to send humans to Mars — agency officials are seeking proposals for studies on advanced technology development.

NASA envisages spending up to $6 million on over 25 proposals this year.

The proposal should focus on technologies that can be used to identify potential targets like sending robotic spacecraft to capture the selected asteroid and put it in a stable orbit beyond the moon.

The technology should also help astronauts get to the space rock and bring back samples in the mid-2020s, NASA said in a statement.

“We are reaching out to seek new and innovative ideas as we extend the frontier of space exploration,” said Bill Gerstenmaier, NASA’s associate administrator for human exploration and operations.

“To reach Mars, we would rely on new technologies and advanced capabilities proven through the Asteroid Initiative. We are looking forward to exciting ideas from outside NASA as well to help realise that vision,” he added.

The proposals have to be submitted before May 5 and the space agency would reward the winners around July 1 for projects that would wrap up in six months.

According to Greg Williams, NASA’s deputy associate administrator for plans and policy, the selection process would build on a workshop that generated hundreds of ideas for asteroid exploration last year.

NASA is already supporting projects such as the Asteroid Data Hunter contest, which is offering $35,000 in awards over the next six months to citizen scientists who come up with improved algorithms for identifying asteroids.

Next year, the space agency would review mission concepts for redirecting an asteroid up to 10 metres wide — or breaking off a piece of a bigger asteroid and bringing it back.

Bad weather halts MH370 search

 

Bad weather has forced the suspension of the search for debris from Malaysia Airlines flight MH370.

Heavy rain, gale force winds and low cloud made a search impracticable, said the Australian Maritime Safety Authority, which is coordinating the search in the southern Indian Ocean.

Air and searches could resume on Wednesday.

Planes from five nations trawling a Lithuania-sized patch of ocean midway between Australia and Antarctica have spotted objects they are trying to locate in the 68,500 sqkm area, 2,500 kilometres south-west of Perth.

So far none of the objects spotted has been located.

The latest sightings — “a grey or green circular object and the second an orange rectangular object” — were spotted on Monday from an Australian Orion maritime surveillance plane.

The Australian Maritime Safety Authority said in its latest statement that all of the various sightings had been in the search area.

The area was plotted using computer modelling of where the plane would have run out of fuel if, as the Malaysians now believe, it flew south after doubling back during a March 8 flight from Kuala Lumpur to Beijing.

The US Navy, which has a surface-skimming P8 Poseidon, described as the world’s most sophisticated maritime patrol aircraft, in the search fleet, is deploying a special undersea device to help find the black box of the lost Boeing 777-200.

The towed pinger locator can identify the characteristic “ping” emitted by the flight recorder from an ocean depth of more than 6,000 metres, the US Defence Department said.

NASA to send robotic mission to Europa

NASA is planning to send a daring robotic mission by 2025 to Jupiter’s watery moon Europa — one of the best bets for alien life beyond Earth in our solar system.

The American space agency has set aside $15 million in its 2015 budget proposal to start planning a mission to Europa.

NASA’s chief financial officer, Elizabeth Robinson, was quoted by The Times as saying that the Europa mission would be launched in the mid-2020s.

Laurie Leshin, astronomer at the Rensselaer Polytechnic Institute in New York, said it would be “a daring mission to an extremely compelling object in our solar system.”

It is the first time the White House has mentioned a Europa mission in its budget, according to Wired.com.

“Clearly this is a statement by NASA that they recognise the priority and excitement of Europa exploration,” commented geologist Robert Pappalardo from NASA’s Propulsion Laboratory (JPL).

Europa is one of the solar system’s most mysterious moons. There may be a vast ocean beneath Europa’s icy crust, with more water in it than exists on all of Earth.

A little bit of that water may be erupting from geysers near the Europa’s south pole, sending plumes 200 kilometres into the air, a recent study has found.

Scientists can send a spacecraft flying through these jets in order to sample their composition.

“I would not be overly optimistic until I see the words, ‘We want to go to Europa’,” from the administration, said planetary scientist Alyssa Rhoden of NASA’s Goddard Spaceflight Center.

Robinson said NASA will look at many competing ideas for a Europa mission, so the agency does not yet know how big or how much it will cost.

Putin orders troops to pull back from border

 

 East-West tensions over Ukraine eased on Tuesday as President Vladimir Putin said he saw no need “for now” to send troops to the neighbouring state and ordered Russian armed forces to be pulled back from Ukraine’s border.“As for the use of armed forces, there is no such need for now,” Mr. Putin said in his first public comments on the Ukraine crisis.Describing use of force as a choice of “last, very last resort,” Mr. Putin warned that he could still go for it if the violence that swept Kiev in recent weeks spilled over to Ukraine’s Russian-speaking eastern regions.Looking relaxed and confident Mr. Putin fielded questions on Ukraine from Russian and foreign journalists for about 90 minutes at a news conference at his state residence outside Moscow.“If people ask us for help — and we have a formal request from [Ukraine’s] legitimate President – we reserve the right to use all means available to protect those citizens,” Mr. Putin said.Addressing a U.N. Security Council emergency meeting on Monday Russia’s Ambassador Vitaly Churkin read out a letter Ukraine’s ousted President Viktor Yanukovych sent to Mr. Putin asking him to use military force in Ukraine to help restore law and order.Mr. Putin denied Russian troops had been deployed in Ukraine’s Crimea. He said the masked armed men who had taken full control of the peninsula were “local forces of self-defence.”The Russian leader confirmed that 1,50,000 troops who had been holding snap military drills near the Ukrainian border over the past seven days were returning to their bases.Asked if he felt concerned that a war could break out in Ukraine, Mr. Putin said: “I’m not worried because we have no plans and will not fight a war against the people of Ukraine.”He said Russia had no intention to annex Crimea. “We are not considering this option. I think only people living on a territory can and should decide their future.”Recalling the case of Kosovo, which gained independence from Serbia, and the right to self-determination enshrined in U.N. documents, Mr. Putin said: “But we will never provoke anybody to take such a decision and will never encourage such sentiments.”While Mr. Putin’s comments helped defuse tensions, the rift between Russia and the West over Ukraine appeared to be widening.Even as U.S. Secretary of State John Kerry arrived in Kiev on Tuesday in a high-profile gesture of support for Ukraine’s new authorities, Mr. Putin denounced the makeover of power in Ukraine as an “unconstitutional coup and armed power grab.”As Mr. Kerry prepared to meet Ukraine’s Acting President Oleksandr Turchynov and Acting Prime Minister Arseniy Yatsenyuk, Mr. Putin said both were “illegitimate” and insisted that Mr. Yanukovych was still the lawful President, even if he “has no political future.”Asked about U.S. threat to penalise Russia, Mr. Putin warned that sanctions would “hurt both sides.”Mr. Putin’s economic adviser Sergei Glazyev said on Tuesday that should the U.S. resort to sanctions, Moscow might drop the dollar as a reserve currency and refuse to repay loans to U.S. banks.

As the Ukrainian Parliament ratified an agreement with the European Union to receive a 610-million Euro loan and the U.S. offered another $1 billion in loan guarantees, Mr. Putin said Gazprom would scrap a heavy price discount it extended to Ukraine in December because of piling debts for earlier supplies.

China hikes defence spending

China on Wednesday announced its biggest hike in military spending in three years, with its defence budget set to cross $ 130 billion in the coming year.Chinese military analysts explained the 12.2 per cent hike as driven by the need to counter a "high risk security environment" in the region, marked in recent months by rising territorial tensions with many neighbours.A draft budget report, which is expected to be approved during the week-long annual session of the National People's Congress (NPC) or Parliament, which opened here on Wednesday morning, proposed a 12.2 per cent hike in defence spending to 808.2 billion Yuan, or $132 billion.This reflected an $ 18 billion rise from the previous year, when the budget rose by 10.7 per cent, and the highest percentage increase since 2011, when spending was hiked by 12.7 per cent.

While Chinese officials said the increase was in keeping with the size of China's growing economy and in line with what most countries spend in terms of percentage of GDP, the 12.2 per cent hike is certain to stir the attention of the region, and particularly China's neighbours.China's spending now dwarfs that of most countries in the region, and is second only to the United States, which spends more than $ 600 billion on defence.Last month, India announced a 10 per cent hike in military spending during the interim budget. On account of the weakening rupee, however, India's effective defence spending in dollar terms actually fell from last year, down to $ 36.2 billion from $ 37.5 billion."There is a yawning gap emerging in the conventional capabilities between China and India," warned Brig. (Retd) Arun Sahgal, Director of the Forum for Strategic Initiative in New Delhi."This asymmetry is increasing by the day, and the fundamental point is that the Chinese, because of a strong economic position and a very definite plan, are focused on military modernisation".Chinese Premier Li Keqiang, who presented the government's annual report to the NPC's opening session, vowed to carry out "coordinated planning for military preparedness in all scenarios" and to push the development of "new and high technology weapons and equipment". He said China would also enhance border, coastal and air defences and "place war preparations on a regular footing".At the same time, his work report said China would "advance neighbourhood diplomacy" and "speed up" infrastructure links with neighbours. Mr. Li specifically highlighted the on-going plans to build a Bangladesh-China-India-Myanmar (BCIM) economic corridor, a "maritime silk road" linking Asia and the Indian and Pacific Oceans, and a corridor linking China and Pakistan as priorities.Chinese military analysts explained the defence hike as a response to China's challenges in the region, such as on-going territorial differences with Japan over East China Sea islands, and recent disputes in the South China Sea."In order to protect the country and safeguard regional peace and stability, China has to enhance its national defence," said Chen Zhou, a researcher with the People's Liberation Army's Academy of Military Sciences and a member of the NPC, adding that China was facing "increasing strategic pressure" with some countries in Asia "speeding up strategic adjustments and strengthening military alliances", in a reference to the U.S. "pivot"."The comparatively low level of input into national defence, coupled with a high-risk security environment, dictates that we must raise our defence budget on a moderate scale," he told the official Xinhua news agency.Asked about fears voiced by some countries in the region, such as Japan, about China's military spending, Qin Gang, the Foreign Ministry spokesperson, said the PLA was not made up of "boy scouts with spears"."Some foreigners always expect China to be a boy scout. In that way, how can we safeguard national security and world peace? Even as a scout grows up, his former dress and shoes will not fit anymore and thus he will have to change into bigger ones," he said.The spending hike will, nevertheless, likely raise concerns, analysts say, as the gulf in military capabilities continues to widen even as territorial disputes remain unresolved.Brig. (Retd) Sahgal said with the increased spending, China's "coercion index" vis-à-vis countries like India had increased."In India, unfortunately, the last decade has been a lost decade," he said. "The Chinese are now increasing their budget by the total Indian defence budget. In the past four years, there hasn't been a single purchase, or modernisation of the three services, while our equipment is getting depleted. What we are seeing," he added, "is that we are now getting out of their league".