The released electrons act as catalysts and accelerate the formation of small clusters of sulfuric acid and water molecules, the building blocks of clouds. Therefore, cosmic rays increase cloud cover on Earth, reflecting sunlight and keeping the planet relatively cool.

Although cold and icy times are generally considered unfriendly to life, the data reveals that biological productivity kept oscillating between very high and very low. The reason, the researchers suggest, is that stronger winds during icy epochs stirred the oceans and improved the supply of nutrients in the surface waters.

To live peacefully with Muslims and Jews, Christians must put aside the notion that their faith requires the creation of a Christian kingdom on Earth, a Lipscomb University theologian told an interfaith gathering at the university.

"We are not going to get very far in our relationship with Jews or Muslims if we do not let go of this idea," Lipscomb professor Lee Camp said at Tuesday's conference.

The unusual gathering of several dozen clergy and lay people was devoted to resolving religious conflict in Nashville and around the world.

"We need to forsake the Christendom model," Camp said. "The most basic Christian commitment      is that we say we believe in the Lordship of Jesus. But, if we claim that, how can a Muslim or Jew trust us, if we say Jesus is the Lord of all Lords?"

Co-sponsored by the First Amendment Center at Vanderbilt University, the daylong conference was prompted by a desire to begin a dialogue about global religious conflict.

Panelists representing different faiths presented their own views on how to begin to bridge the religious divide.

For Kahled Sakalla, a spokesman for the Islamic Center of Nashville, some of the answers lie in better education about Islam in the non-Muslim world.

Allah, the God Muslims worship, is the same God Christians and Jews worship, and the Quran recounts the same biblical stories of Mary and Jesus, he said.

"Yes, we have differences, but it's important to focus on commonalities," said Sakalla, one of four panelists representing different faiths who addressed the Lipscomb conference.

Mark Schiftan, rabbi of the Temple in Belle Meade, said he also believes people of faith must begin to look for common ground.

A special Mass was celebrated on Wednesday at the start of a jubilee year to mark the 25th anniversary of the first apparition of the Blessed Virgin at Kibeho.

The Catholic bishops of Rwanda and Burundi led the celebrations attended by thousands of priests, men and women religious and lay people from Rwanda, Burundi, the Democratic Republic of Congo, Tanzania, Uganda and Europe.

During the Mass the apostolic nuncio Archbishop Anselmo Guido Pecorari read a letter from Pope Benedict XVI announcing that a plenary indulgence had been granted by the Apostolic Penitentiary to pilgrims who visit Kibeho during the Jubilee Year.