Have scientists cracked the speed at which the universe is expanding? - The Week

Have scientists cracked the speed at which the universe is expanding?

Yes — and you'll be pleased to know the magic figure is 73.8 km/sec/megaparsec. So... what the heck does that mean?

POSTED ON MARCH 24, 2011, AT 6:00 AM

A Hubble Space Telescope captures the blue glow of young stars within a galaxy: Scientists say the universe is expanding at an accelerating rate, and that they've pinned down the exact figure. Photo: NASA SEE ALL 44 PHOTOS

Scientists discovered in 1998 that not only is the universe expanding, but it's expanding at a rate that continues to accelerate. Now, using the brightness of a specific type of star and supernova as a guide, they've been able to work out exactly how much faster that expansion happens as the universe grows. Hint — it's very, very fast indeed. Here, a quick guide:

So, how fast is the universe expanding?
The universe is expanding at 73.8 kilometers per second per 3.26 million light years, give or take 2.4 km, according to a study published in the Astrophysical Journal.

Uh, what?
The expansion of space means that galaxies are speeding away from us. The farther away they get, the faster they move. So, according to this equation, a galaxy 3.26 million light years away — or one megaparsec — is moving away from us at around 73.8 kilometers per second. A galaxy two megaparsecs away would be travelling twice as quickly, and so on.

What does this tell us?
It's just more proof that the universe is actually expanding, says Phil Plait at Discover. Some theorized that evidence of expansion was merely an illusion caused by our galaxy's location in a giant void. But the precision of this measurement rules out the so-called "void theory." Now we can go back to studying exactly what is making the universe expand.

What do scientists think is expanding the universe?
Dark energy. That's the name scientists have given to the mysterious force that is causing the universe to expand, rather than give in to the gravitational attraction within it. Understanding this "unknown and undetectable repulsive force" is something of a holy grail for astrophysicists, says Alasdair Wilkins at I09.

Have scientists cracked the speed at which the universe is expanding? - The Week

America's Saudi air war - Features - Al Jazeera English

Controversy has built around a proposal to bring dozens of Saudi pilots to an Idaho training facility to learn how to pilot F-15E Strike Eagles, 84 of which Saudi Arabia is purchasing in a new arms deal [GALLO/GETTY]

On the morning of September 11, 2001, a Saudi pilot trained to fly in the US slammed a Boeing 757 jetliner into the Pentagon, killing more than 180 people.
Less than a decade later, with the Middle East in a state of upheaval and following the recent arrest of a Saudi college student on bomb charges, the Pentagon is planning to bring dozens of Saudis to the US to train them to fly - and to kill.
Last year, when moderate Muslims announced plans to build a community centre in Lower Manhattan, it created a firestorm as Republican politicians, conservative pundits, right-wing websites and survivors of September 11 lined up to assail the "Ground Zero Mosque".
The group 9/11 Families for a Safe & Strong America called the proposal "a gross insult to the memory of those who were killed on that terrible day." While Peter Gadiel, the president of 9/11 Families for a Secure America, wrote: "The proposed mosque near the site of the 9/11 mass murder is a continuation of Islam's violent history, which promotes destroying prior cultures and building on the ruins."
The choir of Islamophobia
Three of the many who joined the chorus against building an Islamic cultural centre two blocks from where seven Saudi terrorists helped to kill more than 2,700 people were congressman Mike Simpson and senators Jim Rischand Mike Crapo, all from Idaho.
"I do not believe the construction of this Islamic centre so near to Ground Zero is proper," insisted Crapo.
"This construction proposal is proving highly divisive to Americans across the political spectrum who are still seeking to recover fully from the emotional, economic and social scars caused by the terrorist attacks."
Simpson echoed those sentiments, stating: "I think building a mosque at Ground Zero is inappropriate and insensitive."
While Risch put his feelings this way: "Considering what occurred at Ground Zero in New York City I completely sympathise with those who object to a mosque being built in that area."
All three Idaho politicians, however, have come out in favour of hosting hundreds of Saudi military personnel and their families at a US air force base in Idaho where they will be trained by US air force personnel to fly advanced fighter aircraft and learn the fundamentals of aerial combat.
While active-duty military personnel and veterans have also lined up behind the air force plan, some locals, as well as members of the right-wing blogosphere and others who opposed the building of the Islamic cultural centre, have begun to voice outrage.
When I contacted Peter Gadiel, whose son was killed in the World Trade Centre, and asked him about the prospect of the US air force training Saudi pilots in Idaho, he was blunt. "Americans will die and the people in Washington don't give a damn," he said.

America's Saudi air war - Features - Al Jazeera English