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Maybe some readers recall Immanuel Velikovsky's 1950 mega bestseller Worlds in Collision. The book, which caused a real sensation at the time, was an attempt to "explain" many of the big cataclysms and "miracles" recorded in mythic and folkloric narratives of ancient cultures as real astrophysical events. Velikovsky's thesis was that narratives of floods and mass destructions were not just allegorical or metaphorical but records of events that did take place. Mythic and biblical catastrophism had a historical and a scientific value to them.

In Velikovsky's theory, Venus was ejected from Jupiter as a kind of comet sometime around the 15th century BCE. Its periodic passage by Earth caused all sorts of havoc. His mythic inspiration came from Greek mythology, in particular the fable where Athena (Venus) was ejected from the head of Zeus (Jupiter). In spite of its popular appeal, the astronomical community summarily dismissed Velikovsky's ideas, a key player having been none other than Carl Sagan, who knew a lot about Venus and its atmosphere. In any case, Velikovsky's celestial catastrophism follows on the footsteps of many claims of apocalyptic endings due to upheavals in the skies. And even if his thesis was unfounded, bad things can and do happen from time to time due to collisions between "worlds." Think, for example, of the demise of the dinosaurs 65 millions years ago due a collision with a seven-mile wide asteroid.

Still, Velikovsky's doomsday imaginings are a child's play compared to some catastrophic ideas that modern cosmologists have been putting forward. I don't mean the devastation caused by a collision with an asteroid or comet, but of whole universes colliding with one another, including with our own.

Welcome to cosmic catastrophism.

The universe began its existence 13.7 billion years ago and has been expanding ever since. However, current observations indicate that this expansion wasn't always at the same rate. Right at the beginning of time, the cosmos underwent a short period of hyper-accelerated expansion called inflation. According to this theory, proposed by MIT cosmologist Alan Guth in 1981, our whole universe could have emerged from a tiny patch of space that was stretched like a rubber band by the enormous factor of one hundred trillion trillion times (1026) in a fraction of a second. The universe we observe today fits within this stretched region, like an island in an ocean.

Now imagine that other portions of space, neighbors to that tiny patch that gave rise to our universe, also got stretched at different rates and at different times. We would have a universe filled with island-universes, each with its own history and possibly even types of matter, etc. This ocean of island-universes is called the multiverse.

Since physics is an empirical science, any hypothesis needs to be tested before being accepted by the community. This is as true for a ball rolling down a hill as for Guth's inflating universe or the multiverse. For the ball, we know how to apply Newton's laws of motion to describe its rolling and the results come out in excellent agreement with observations. Cosmic inflation predicts that our universe is geometrically flat (or almost) like the surface of a table but in three dimensions; it also predicts that space should be filled with radiation with a uniform temperature, as bathwater fills a bathtub. These two predictions have been confirmed, although a skeptic could argue that inflation was designed to accommodate these two observational facts about the universe. To its merit, inflation also offers an explanation as to how galaxies were first born and then grouped together in clusters, something that no other theory can do satisfactorily. Cosmologists like inflation a lot for its simplicity and range of explanation.

Since we can't receive information from outside our universe (or better, from outside our "horizon", the sphere that delimits how far light travelled in 13.7 billion years), how can we possibly test the existence of other universes "out there"? This has been a sticky point with the multiverse and indeed, the notion that the multiverse extends perhaps to spatial infinity is untestable. Infinity makes sense mathematically and may even be realized in Nature; but we will never know for sure.

However, we can do the next best thing, and see if at least neighboring universes exist. Just as with soap bubbles that vibrate when they collide with one another without popping, if another universe collided with ours in the distant past, the radiation inside our universe would have vibrated in response to the perturbations caused by the collision. These perturbations would be registered in the cosmic radiation and could, in principle, be observed. Matthew Kleban from New York University and his collaborators, and Anthony Aguirre from the University of California at Santa Cruz and his have been studying what kinds of signals would be left over from these dramatic events. Kleban found a unique signature, concentric rings where the radiation temperature would show a characteristic fluctuation. On top of the rings the radiation itself would be polarized, that is, it would oscillate in tandem in a specific direction of the sky. At least for now, no telltale rings have been found in the cosmic radiation, although the European satellite Planck promises to deliver more accurate polarization data that may shed light on the issue.

The bad news is that the probability of a collision with another universe increases with time: we could disappear at any instant: live life to the fullest!

The good news is that, although the multiverse as a whole may not be a testable scientific hypothesis, with some luck we may at least know if one or a few other universes exist. An observational test distinguishes science from idle speculation.

The announcement from Sen. Jay Rockefeller, D-W.Va., that he will not seek a sixth term in 2014, would seem to give Republicans a big opening in a state that has gone deep red in recent presidential elections.

But West Virginia's animus toward recent Democrats in the White House, especially President Obama, doesn't necessarily translate into Republican advantages in statewide races.

Both senators, the state's governor and one of its three members of the House are Democrats. And the state that produced legendary Democratic Sen. Robert Byrd (who brought the state "billions of dollars for highways, federal offices, research institutes and dams," as The New York Times noted in its 2010 obituary) hasn't elected a Republican senator since the 1950s.

"As I approach 50 years of public service in West Virginia, I've decided that 2014 will be the right moment for me to find new ways to fight for the causes I believe in and to spend more time with my incredible family," Rockefeller announced in a statement.

Rockefeller, 75, chairman of the Senate Commerce, Science and Transportation Committee, has been a senator for 28 years from his adopted home state.

Rep. Shelley Moore Capito, R-W.Va., already had said she would run for Rockefeller's Senate seat in 2014.

The Washington Post reports that a slew of Democrats could be in the mix as well:

"The crowded 2011 Democratic gubernatorial primary may offer hints about which Democrats are likely to take the plunge in the Senate race. The runners up to current Gov. Earl Ray Tomblin include Secretary of State Natalie Tennant, state House Speaker Rick Thompson, and state Treasurer John Perdue, among others. The state's only Democrat in the House delegation, Rep. Nick Rahall, is another possibility, as is former Sen. Carte Goodwin, who served for a brief stint in 2010."

Vice President Joe Biden is getting ready to make recommendations on how to reduce gun violence in the wake of the school shooting in Newtown, Conn.

But he says his task force is facing an unexpected obstacle: slim or outdated research on weapons.

Public health research dried up more than a decade ago after Congress restricted the use of some federal money to pay for those studies.

A Researcher Under Fire

Art Kellermann was raised in eastern Tennessee, where his father taught him how to shoot a long gun when he was 10 years old. Kellermann grew up to become an emergency room doctor — and a target for gun-rights groups when he started asking questions like, "If a gun kept in a home was used, who did it shoot, and what were the consequences?"

Kellermann found people turned those guns on themselves and others in the house far more often than on intruders. "In other words, a gun kept in the home was 43 times more likely to be involved in the death of a member of the household than to be used in self-defense," he says.

Kellermann says the National Rifle Association and other Second Amendment advocates leaned on his then-employer, Emory University, to stop the research. That didn't work.

So, he says, "they turned to a softer target, which was the [Centers for Disease Control and Prevention], the organization that was funding much of this work. And although gun injury prevention research was never more than a tiny percentage of the CDC's research budget, it was enough to bring them under the fire of the NRA."

The Tiahrt Amendments

Lawmakers — both Democrats and Republicans — held back some money from the CDC and made clear that no federal funds should be used to promote gun control.

Many researchers interpreted that message to mean no public health studies about injuries from weapons.

Then, a few years later, Congress weighed in again, in a slightly different way.

In 2003, Rep. Todd Tiahrt, a Republican from Kansas, added language to the Justice Department's annual spending bill. It says the Bureau of Alcohol, Tobacco, Firearms and Explosives can't release information used to trace guns involved in crime to researchers and members of the public. It also requires the FBI to destroy records on people approved to buy guns within 24 hours.

Tiahrt left Congress in 2011, but he still thinks the idea is a good one.

"It was an issue of privacy; it's an issue of protecting undercover officers, prison guards," he says. "The BATFE was also very concerned because if that information was released to the public, it could affect their efforts to try to get illegal guns and illegal gun sales ... off the street."

Tiahrt says some of his fears about invasion of privacy were borne out last month, when a New York newspaper got local gun permit data and published the names of gun owners.

'Good Data'

Mark Glaze, who directs the group Mayors Against Illegal Guns, says he thinks it was "a bad idea that the newspaper did this," but he says the right response to that case is not to shut down the flow of information.

"You can't make good policy unless you have good data," he says.

Glaze is pressing Congress to get rid of the Tiahrt amendments. He's urging the Justice Department to look for patterns involving crooked gun dealers who put weapons into the hands of criminals. And he wants more money for research about how to make safer guns.

Rep. Rosa DeLauro of Connecticut, the top Democrat on the House committee that deals with the health budget, puts it this way: "We conduct evidence-based research into car crashes, smoking, cancer, all sorts of accidents and injuries. So why shouldn't we be doing the same kind of research into how to prevent firearm injuries and how to save lives?"

DeLauro says she'll fight to make sure funding limits on research stay out of appropriations bills.

But Tiahrt, her onetime colleague, says that's not the core of the problem.

"We have to get to the cause of it: mental illness, the violence in our culture," he says. "Those are the things that I think Vice President Biden ought to be focusing on."

Public health experts like Kellermann say they're willing to have that kind of broad conversation, but it needs to be supported with a lot more research.

President Obama will hold a news conference today at 11:15 a.m. ET, it was just announced.

It will be held in the East Room of the White House.

Barring some surprise, this will be the last news conference during his first term. The president will take the oath of office for his second term next Sunday (in a private ceremony) and then again Monday on the steps of the Capitol.

Among the topics likely to be discussed at his news conference: the budget, gun control, the economy, Afghanistan and immigration.

We'll live blog as he speaks.