Earth may be crashing through dark matter walls

Earth is constantly crashing through huge walls of dark matter, and we already have the tools to detect them. That's the conclusion of physicists who say the universe may be filled with a patchwork quilt of force fields created shortly after the big bang.

Observations of how mass clumps in space suggest that about 86 per cent of all matter is invisible dark matter, which interacts with ordinary matter mainly through gravity. The most popular theory is that dark matter is made of weakly interacting massive particles.

WIMPs should also interact with ordinary matter via the weak nuclear force, and their presence should have slight but measurable effects. However, years of searches for WIMPs have been coming up empty.

"So far nothing is found, and I feel like it's time to broaden the scope of our search," says Maxim Pospelov of the University of Victoria in Canada. "What we propose is to look for some other signatures."

Bubbly cosmos

Pospelov and colleagues have been examining a theory that at least some of the universe's dark matter is tied up in structures called domain walls, akin to the boundaries between tightly packed bubbles. The idea is that the hot early universe was full of an exotic force field that varied randomly. As the universe expanded and cooled, the field froze, leaving a patchwork of domains, each with its own distinct value for the field.

Having different fields sit next to each other requires energy to be stored within the domain walls. Mass and energy are interchangeable, so on a large scale a network of domain walls can look like concentrations of mass – that is, like dark matter, says Pospelov.

If the grid of domain walls is packed tightly enough – say, if the width of the domains is several hundred times the distance between Earth and the sun – Earth should pass through a domain wall once every few years. "As a human, you wouldn't feel a thing," says Pospelov. "You will go through the wall without noticing." But magnetometers – devices that, as the name suggests, measure magnetic fields – could detect the walls, say Pospelov and colleagues in a new study. Although the field inside a domain would not affect a magnetometer, the device would sense the change when Earth passes through a domain wall.

Dark matter walls have not been detected yet because anyone using a single magnetometer would find the readings swamped by noise, Pospelov says. "You'd never be able to say if it's because the Earth went through a bizarre magnetic field or if a grad student dropped their iPhone or something," he says.

Network needed

Finding the walls will require a network of at least five detectors spread around the world, Pospelov suggests. Colleagues in Poland and California have already built one magnetometer each and have shown that they are sensitive enough for the scheme to work.

Domain walls wouldn't account for all the dark matter in the universe, but they could explain why finding particles of the stuff has been such a challenge, says Pospelov.

If domain walls are found, the news might come as a relief to physicists still waiting for WIMPs to show up. Earlier this month, for instance, a team working with a detector in Russia that has been running for more than 24 years announced that they have yet to see any sign of these dark matter candidates.

Douglas Finkbeiner of the Harvard-Smithsonian Center for Astrophysics, who was not involved in Pospelov's study, isn't yet convinced that dark matter walls exist. But he is glad that physicists are keeping an open mind about alternatives to WIMPs.

"We've looked for WIMP dark matter in so many ways," he says. "At some point you have to ask, are we totally on the wrong track?"

Journal reference: Physical Review Letters, DOI: 10.1103/PhysRevLett.110.021803

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China 'strongly dissatisfied' with US island remarks

BEIJING: China said it was "strongly dissatisfied" Sunday after US Secretary of State Hillary Clinton issued a veiled warning to Beijing not to challenge Tokyo's control of disputed islands at the centre of a bitter territorial row.

China is "strongly dissatisfied with and resolutely opposes" the remarks, Foreign Ministry spokesman Qin Gang said in a statement on the ministry's website.

The maritime dispute, which has simmered off and on for years, intensified last year when the Japanese government nationalised islands in the small chain it did not already own, triggering angry responses in China.

China has since increased maritime and air patrols near the East China Sea territory, and in further escalations in recent weeks both Beijing and Tokyo have scrambled fighter jets, though there have been no clashes.

"We urge the US side to treat the issue of the Diaoyu islands with a responsible attitude," Qin said, referring to the territory by its Chinese name. Japan calls the islands the Senkakus.

He also called for Washington to be "careful in words, cautious in actions" and to take "realistic actions to protect the peace and stability of the region and Chinese-US relations".

Qin's statement came after Clinton on Friday said the US opposed "any unilateral actions that would seek to undermine Japanese administration" of the islands.

Clinton, speaking at a press conference with Japanese Foreign Minister Fumio Kishida in Washington, did not mention Beijing directly but said she wanted China and Japan to settle the issue peacefully.

"We do not want to see any action taken by anyone that could raise tensions or result in miscalculation that would undermine the peace, security and economic growth in this region," she said.

The US insists it is neutral on the ultimate sovereignty of the islands but also says they are under Japan's de facto administration.

China has persistently criticised the US position and Beijing's sending of maritime surveillance ships to the potentially gas-rich area is seen by experts as a way to contest the notion of Japanese control.

Complicating the issue is a security treaty that obliges the US -- which keeps military bases in Japan -- to aid the country in the event it is attacked.

Another factor that has raised tensions is the coming to power last month of hawkish Japanese Prime Minister Shinzo Abe, whose party won a landslide victory in elections.

Last week, state media said China will carry out a geographical survey of the islands and also reported that China's armed forces have been instructed to raise their fighting ability in 2013 with "the objective of being able to fight and win a battle".

China's official reaction to Clinton's comments came a day after state media harshly criticised them.

The official Xinhua news agency called it "unwise" for Washington "to throw support behind Japan in Tokyo's islands dispute with Beijing", adding: "This unbalanced position has betrayed its declared intention to stay neutral on the issue."

- AFP/ck

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WikiLeaks says Aaron Swartz may have been a 'source'

WikiLeaks said late yesterday that recently deceased Internet activist Aaron Swartz assisted the organization, was in contact with Julian Assange, and may have been one of the organization's sources.

Reached in Iceland on Saturday evening, California time, WikiLeaks representative Kristinn Hrafnsson confirmed to CNET that the tweets were authentic but declined to elaborate.

In the tweets, the organization said it was revealing the information "due to the investigation into the Secret Service involvement" with Swartz.

Here are screenshots of the tweets:

The phrasing of the last tweet ("strong reasons to believe, but cannot prove") may be related to the precautions WikiLeaks says it takes to ensure its sources' anonymity. WikiLeaks' policy says:

...we operate a number of servers across multiple international jurisdictions and we we do not keep logs. Hence these logs can not be seized. Anonymization occurs early in the WikiLeaks network, long before information passes to our web servers. Without specialized global internet traffic analysis, multiple parts of our organisation must conspire with each other to strip submitters of their anonymity.

The Secret Service has a legal mandate to investigate computer crime, a task it shares with the FBI and other federal agencies, which the agency describes including "unauthorized access to protected computers" -- which Swartz is alleged to have been guilty of. It also investigates forgery, identity fraud, visa fraud, money laundering, food stamp fraud, wire fraud, and a host of other federal offenses.

It would not be unusual, in other words, for the Secret Service to be involved in a criminal probe of Swartz's alleged bulk downloading from the JSTOR database. Some other examples: The Secret Service, which is now part of the Department of Homeland Security, has investigated an artist who installed photo-taking software in Apple stores, a credit card theft ring, spyware installed on college campuses, and a possible theft of GOP candidate Mitt Romney's income tax returns.

The ambiguous WikiLeaks tweets have prompted speculation about what the group was trying to suggest. The Verge's Tim Carmody wrote that "the aim of these tweets could be to imply that the US Attorney's Office and Secret Service targeted Swartz in order to get at WikiLeaks, and that Swartz died still defending his contacts' anonymity. Taking that implied claim at face value would be irresponsible without more evidence." And blog emptywheel wrote that if true, the tweets "strongly indicate" that "the US government used the grand jury investigation into Aaron's JSTOR downloads as a premise to investigate WikiLeaks."

Until WikiLeaks elaborates on what it intended to say by highlighting the Secret Service's involvement, and provides supporting evidence, it will be difficult to draw any conclusions.

After confirming the authenticity of the tweets, WikiLeaks representative Hrafnsson asked that we contact him later with any further questions. We'll do that and let you know what we find out.

It seems the only thing that's now certain is that criticisms of, and speculation about, the government's handling of the Swartz-Jstor case isn't likely to die down overnight.

CNET's Declan McCullagh contributed to this report.

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Attack at Algeria Gas Plant Heralds New Risks for Energy Development

The siege by Islamic militants at a remote Sahara desert natural gas plant in Algeria this week signaled heightened dangers in the region for international oil companies, at a time when they have been expanding operations in Africa as one of the world's last energy frontiers. (See related story: "Pictures: Four New Offshore Drilling Frontiers.")

As BP, Norway's Statoil, Italy's Eni, and other companies evacuated personnel from Algeria, it was not immediately clear how widely the peril would spread in the wake of the hostage-taking at the sprawling In Amenas gas complex near the Libyan border.

Map by National Geographic

Algeria, the fourth-largest crude oil producer on the continent and a major exporter of natural gas and refined fuels, may not have been viewed as the most hospitable climate for foreign energy companies, but that was due to unfavorable financial terms, bureaucracy, and corruption. The energy facilities themselves appeared to be safe, with multiple layers of security provided both by the companies and by government forces, several experts said. (See related photos: "Oil States: Are They Stable? Why It Matters.")

"It is particularly striking not only because it hasn't happened before, but because it happened in Algeria, one of the stronger states in the region," says Hanan Amin-Salem, a senior manager at the industry consulting firm PFC Energy, who specializes in country risk. She noted that in the long civil war that gripped the country throughout the 1990s, there had never been an attack on Algeria's energy complex. But now, hazard has spread from weak surrounding states, as the assault on In Amenas was carried out in an apparent retaliation for a move by French forces against the Islamists who had taken over Timbuktu and other towns in neighboring Mali. (See related story: "Timbuktu Falls.")

"What you're really seeing is an intensification of the fundamental problem of weak states, and empowerment of heavily armed groups that are really well motivated and want to pursue a set of aims," said Amin-Salem. In PFC Energy's view, she says, risk has increased in Mauritania, Chad, and Niger—indeed, throughout Sahel, the belt that bisects North Africa, separating the Sahara in the north from the tropical forests further south.

On Thursday, the London-based corporate consulting firm Exclusive Analysis, which was recently acquired by the global consultancy IHS, sent an alert to clients warning that oil and gas facilities near the Libyan and Mauritanian borders and in Mauritania's Hodh Ech Chargui province were at "high risk" of attack by jihadis.

"A Hot Place to Drill"

The attack at In Amenas comes at a time of unprecedented growth for the oil industry in Africa. (See related gallery: "Pictures: The Year's Most Overlooked Energy Stories.") Forecasters expect that oil output throughout Africa will double by 2025, says Amy Myers Jaffe, executive director of the energy and sustainability program at the University of California, Davis, who has counted 20 rounds of bidding for new exploration at sites in Africa's six largest oil-producing states.

Oil and natural gas are a large part of the Algerian economy, accounting for 60 percent of government budget revenues, more than a third of GDP and more than 97 percent of its export earnings. But the nation's resources are seen as largely undeveloped, and Algeria has tried to attract new investment. Over the past year, the government has sought to reform the law to boost foreign companies' interests in their investments, although those efforts have foundered.

Technology has been one of the factors driving the opening up of Africa to deeper energy exploration. Offshore and deepwater drilling success in the Gulf of Mexico and Brazil led to prospecting now under way offshore in Ghana, Mozambique, and elsewhere. (See related story: "New Oil—And a Huge Challenge—for Ghana.") Jaffe says the Houston-based company Anadarko Petroleum has sought to transfer its success in "subsalt seismic" exploration technology, surveying reserves hidden beneath the hard salt layer at the bottom of the sea, to the equally challenging seismic exploration beneath the sands of the Sahara in Algeria, where it now has three oil and gas operations.

Africa also is seen as one of the few remaining oil-rich regions of the world where foreign oil companies can obtain production-sharing agreements with governments, contracts that allow them a share of the revenue from the barrels they produce, instead of more limited service contracts for work performed.

"You now have the technology to tap the resources more effectively, and the fiscal terms are going to be more attractive than elsewhere—you put these things together and it's been a hot place to drill," says Jaffe, who doesn't see the energy industry's interest in Africa waning, despite the increased terrorism risk. "What I think will happen in some of these countries is that the companies are going to reveal new securities systems and procedures they have to keep workers safe," she says. "I don't think they will abandon these countries."

This story is part of a special series that explores energy issues. For more, visit The Great Energy Challenge.

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Algeria Hostage Crisis Over, One American Dead

After the Algerian military's final assault on terrorists holding hostages at a gas complex, the four-day hostage crisis is over, but apparently with additional loss of life among the foreign hostages.

One American, Fred Buttaccio of Texas, has been confirmed dead by the U.S. State Department. Two more U.S. hostages remain unaccounted for, with growing concern among U.S. officials that they did not survive.

But another American, Mark Cobb of Corpus Christi, Texas is now confirmed as safe. Sources close to his family say Cobb, who is a senior manager of the facility, is safe and reportedly sent a text message " I'm alive."

Inside Algerian Hostage Crisis, One American Dead Watch Video

American Hostages Escape From Algeria Terrorists Watch Video

In a statement, President Obama said, "Today, the thoughts and prayers of the American people are with the families of all those who were killed and injured in the terrorist attack in Algeria. The blame for this tragedy rests with the terrorists who carried it out, and the United States condemns their actions in the strongest possible terms. ... This attack is another reminder of the threat posed by al Qaeda and other violent extremist groups in North Africa."

According to Algerian state media, 32 militants are dead and a total of 23 hostages perished during the four-day siege of the In Amenas facility in the Sahara. The Algerian Interior Ministry also says 107 foreign nationals who worked at the facility for BP and other firms were rescued or escaped from the al Qaeda-linked terrorists who took over the BP joint venture facility on Wednesday.

The Japanese government says it fears "very grave" news, with multiple casualties among the 10 Japanese citizens working at the In Amenas gas plant.

Five British nationals and one U.K. resident are either deceased or unaccounted for in the country, according to British Foreign Minister William Hague. Hague also said that the Algerians have reported that they are still trying to clear boobytraps from the site.

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NASA planet-hunter is injured and resting

Lisa Grossman, physical sciences reporter

(Image: NASA/Kepler mission/Wendy Stenzel)

NASA's planet-hunting Kepler telescope has put its search for alien Earths on hold while it rests a stressed reaction wheel.

The injured wheel normally helps to control the telescope's orientation, keeping it pointed continuously at the same patch of sky. Kepler stares at the thousands of stars in its field of view to watch for the telltale blinks that occur when a planet crosses in front of its star. It has found nearly 3000 potential planets outside our solar system since its launch in 2009, transforming the field of exoplanet research and raising hopes of someday finding alien life.

When it launched, Kepler had four reaction wheels: three to control its motion along each axis, and one spare. But last July, one wheel stopped turning. If the spacecraft loses a second wheel, the mission is over.

So when another wheel started showing signs of elevated friction on 7 January, the team decided to play it safe. After rotating the spacecraft failed to fix the problem, NASA announced yesterday that they're placing Kepler in safe mode for 10 days to give the wheel a chance to recover.

The hope is that the lubricating oil that helps the wheel's ball bearings run smoothly around a track will redistribute itself during the rest period.

The telescope can't take any science data while in safe mode. But if the wheel recovers on its own, Kepler's extended mission will run until 2016, leaving it plenty of time to make up for the lost days.

"Kepler is a statistical mission," says Charlie Sobeck, Kepler's deputy project manager at NASA's Ames Research Centre in Mountain View, California. "In the long run, as long as we make the observations, it doesn't matter a lot when we make the observations."

Despite the high stakes, the team doesn't seem too worried.

"Each wheel has its own personality, and this particular wheel has been something of a free spirit," Sobeck says. "It's had elevated torques throughout the mission. This one is typical to what we've seen in the past, and if we had four good wheels we probably wouldn't have taken any action."

"I prefer to picture the spacecraft lounging at the shore of the cosmic ocean sipping a Mai Tai so that she'll be refreshed and rejuvenated for more discoveries," wrote Kepler co-investigator Natalie Batalha in an email.

The team will check up on the wheel on 27 January and return to doing science as soon as possible.

There are two exoplanet missions currently being considered for after Kepler is finished, says Doug Hudgins at NASA Headquarters in Washington, DC. One, TESS (Terrestrial Exoplanet Survey Satellite), would scan the entire sky for planets transiting the stars nearest to the sun. The other, FINESSE (Fast Infrared Exoplanet Spectroscopy Survey Explorer), would take spectra of planets as they passed in front of their stars as a way to probe their atmospheres.

The missions are being evaluated now, and NASA will probably select one this spring, Hudgins says. The winner will launch in 2017.

If Kepler goes down with its reaction wheel, that won't affect which mission wins, he adds. "That's a straight-up competition based on the merits of the two concept study reports."

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IRCC to step up outreach to community

SINGAPORE: The Inter-Racial and Religious Confidence Circle (IRCC) has launched a newsletter and a song to step up its efforts to reach out to the community.

The newsletter that comes out every three months aims to increase awareness of IRCCs to the community at-large as it shares the key thrusts of IRCCs, strategies that IRCCs undertake to achieve them and updates readers on upcoming events and activities.

It will also help spread the IRCC messages of racial and religious understanding to readers, and complement the IRCC website in outreach and engagement efforts. An electronic version of the IRCC Newsletter is also available on the website.

The song composed by well-known local musicians, Jack and Rai, is titled "Different Races.Many Beliefs.One Nation".

It reflects the roles and functions of IRCCs, as well as highlights the importance of racial and religious harmony in a creative and catchy manner.

Launching the newsletter and song was Acting Minister for Culture, Community and Youth Lawrence Wong at the IRCC Family Day on Saturday afternoon.

He said the newsletter will help augment the IRCC's efforts in reaching out to more people, so that everyone in Singapore can play a part in maintaining racial and religious harmony.

- CNA/ck

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Crave Ep. 105: How to clip your nails in space

How to clip your nails in space, Ep. 105

Subscribe to Crave:

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This week on Crave, we're back from
CES with a look at some of the wackier stuff we spotted at the show. Then, Canadian astronaut Christopher Hadfield gives us a highly important grooming lesson on the safest way to clip our nails in outer space, and the Hal 9000 computer replica from ThinkGeek refuses to cooperate.

Crave stories:

- From iPad toilets to alien apps, CES brims with oddities

- I took a power drill to an iPhone at CES

- Electric ZBoard is controlled with your weight

- Get ready to program! Lego's Mindstorms EV3 robots are here

- The mind-controlled helicopter from Puzzlebox

- How to clip your fingernails in space without inhaling them

- Movie-accurate HAL 9000 bosses you around the house

- Vroom vroom: Mario Kart gets real-life run

Social networking:

- Stephen on Twitter

- Stephen on Google+

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Attack at Algeria Gas Plant Heralds New Risks for Energy Development

The siege by Islamic militants at a remote Sahara desert natural gas plant in Algeria this week signaled heightened dangers in the region for international oil companies, at a time when they have been expanding operations in Africa as one of the world's last energy frontiers. (See related story: "Pictures: Four New Offshore Drilling Frontiers.")

As BP, Norway's Statoil, Italy's Eni, and other companies evacuated personnel from Algeria, it was not immediately clear how widely the peril would spread in the wake of the hostage-taking at the sprawling In Amenas gas complex near the Libyan border.

Map by National Geographic

Algeria, the fourth-largest crude oil producer on the continent and a major exporter of natural gas and refined fuels, may not have been viewed as the most hospitable climate for foreign energy companies, but that was due to unfavorable financial terms, bureaucracy, and corruption. The energy facilities themselves appeared to be safe, with multiple layers of security provided both by the companies and by government forces, several experts said. (See related photos: "Oil States: Are They Stable? Why It Matters.")

"It is particularly striking not only because it hasn't happened before, but because it happened in Algeria, one of the stronger states in the region," says Hanan Amin-Salem, a senior manager at the industry consulting firm PFC Energy, who specializes in country risk. She noted that in the long civil war that gripped the country throughout the 1990s, there had never been an attack on Algeria's energy complex. But now, hazard has spread from weak surrounding states, as the assault on In Amenas was carried out in an apparent retaliation for a move by French forces against the Islamists who had taken over Timbuktu and other towns in neighboring Mali. (See related story: "Timbuktu Falls.")

"What you're really seeing is an intensification of the fundamental problem of weak states, and empowerment of heavily armed groups that are really well motivated and want to pursue a set of aims," said Amin-Salem. In PFC Energy's view, she says, risk has increased in Mauritania, Chad, and Niger—indeed, throughout Sahel, the belt that bisects North Africa, separating the Sahara in the north from the tropical forests further south.

On Thursday, the London-based corporate consulting firm Exclusive Analysis, which was recently acquired by the global consultancy IHS, sent an alert to clients warning that oil and gas facilities near the Libyan and Mauritanian borders and in Mauritania's Hodh Ech Chargui province were at "high risk" of attack by jihadis.

"A Hot Place to Drill"

The attack at In Amenas comes at a time of unprecedented growth for the oil industry in Africa. (See related gallery: "Pictures: The Year's Most Overlooked Energy Stories.") Forecasters expect that oil output throughout Africa will double by 2025, says Amy Myers Jaffe, executive director of the energy and sustainability program at the University of California, Davis, who has counted 20 rounds of bidding for new exploration at sites in Africa's six largest oil-producing states.

Oil and natural gas are a large part of the Algerian economy, accounting for 60 percent of government budget revenues, more than a third of GDP and more than 97 percent of its export earnings. But the nation's resources are seen as largely undeveloped, and Algeria has tried to attract new investment. Over the past year, the government has sought to reform the law to boost foreign companies' interests in their investments, although those efforts have foundered.

Technology has been one of the factors driving the opening up of Africa to deeper energy exploration. Offshore and deepwater drilling success in the Gulf of Mexico and Brazil led to prospecting now under way offshore in Ghana, Mozambique, and elsewhere. (See related story: "New Oil—And a Huge Challenge—for Ghana.") Jaffe says the Houston-based company Anadarko Petroleum has sought to transfer its success in "subsalt seismic" exploration technology, surveying reserves hidden beneath the hard salt layer at the bottom of the sea, to the equally challenging seismic exploration beneath the sands of the Sahara in Algeria, where it now has three oil and gas operations.

Africa also is seen as one of the few remaining oil-rich regions of the world where foreign oil companies can obtain production-sharing agreements with governments, contracts that allow them a share of the revenue from the barrels they produce, instead of more limited service contracts for work performed.

"You now have the technology to tap the resources more effectively, and the fiscal terms are going to be more attractive than elsewhere—you put these things together and it's been a hot place to drill," says Jaffe, who doesn't see the energy industry's interest in Africa waning, despite the increased terrorism risk. "What I think will happen in some of these countries is that the companies are going to reveal new securities systems and procedures they have to keep workers safe," she says. "I don't think they will abandon these countries."

This story is part of a special series that explores energy issues. For more, visit The Great Energy Challenge.

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Armstrong Tearful Over Telling Kids Truth

Lance Armstrong, 41, began to cry today as he described finding out his son Luke, 13, was publicly defending him from accusations that he doped during his cycling career.

Armstrong said that he knew, at that moment, that he would have to publicly admit to taking performance-enhancing drugs and having oxygen-boosting blood transfusions when competing in the Tour de France. He made those admissions to Oprah Winfrey in a two-part interview airing Thursday and tonight.

"When this all really started, I saw my son defending me, and saying, 'That's not true. What you're saying about my dad? That's not true,'" Armstrong said, tearing up during the second installment of his interview tonight. "And it almost goes to this question of, 'Why now?'

"That's when I knew I had to talk," Armstrong said. "He never asked me. He never said, 'Dad, is this true?' He trusted me."

He told Winfrey that he sat down with his children over the holidays to come clean about his drug use.

"I said, 'Listen, there's been a lot of questions about your dad, about my career and whether I doped or did not dope,'" he said he told them. "'I always denied that. I've always been ruthless and defiant about that, which is why you defended me, which makes it even sicker' I said, 'I want you to know that it's true.'"

He added that his mother was "a wreck" over the scandal.

Armstrong said that the lowest point in his fall from grace and the top of the cycling world came when his cancer charity, Livestrong, asked him to consider stepping down.

George Burns/Harpo Studios, Inc.

Lance Armstrong-Winfrey Interview: How Honest Was He? Watch Video

Lance Armstrong-Winfrey Interview: Doping Confession Watch Video

After the U.S. Anti-Doping Agency alleged in October that Armstrong doped throughout his reign as Tour de France champion, Armstrong said, his major sponsors -- including Nike, Anheuser Busch and Trek -- called one by one to end their endorsement contracts with him.

"Everybody out," he said. "Still not the most humbling moment."

Then came the call from Livestrong, the charity he founded at age 25 when he was diagnosed with testicular cancer.

"The story was getting out of control, which was my worst nightmare," he said. "I had this place in my mind that they would all leave. The one I didn't think would leave was the foundation.

"That was most humbling moment," he said.

Armstrong first stepped down as chairman of the board for the charity before being asked to end his association with the charity entirely. Livestrong is now run independently of Armstrong.

"I don't think it was 'We need you to step down,' but, 'We need you to consider stepping down for yourself,'" he said, recounting the call. "I had to think about that a lot. None of my kids, none of my friends have said, 'You're out,' and the foundation was like my sixth child. To make that decision, to step aside, that was big."

In Thursday's interview installment, the seven-time winner of the Tour de France admitted publicly for the first time that he doped throughout his career, confirming after months of angry denials the findings of the U.S. Anti-Doping Agency, which stripped him of his titles in October.

He told Winfrey that he was taking the opportunity to confess to everything he had done wrong, including for years angrily denying claims that he had doped.

READ MORE: Armstrong Admits to Doping

WATCH: Armstrong's Many Denials Caught on Tape

READ MORE: 10 Scandalous Public Confessions

Read More..