A Bigger, Older Universe? at Wolverine’s Den

A Bigger, Older Universe?

03Aug06

M33

M33 (NGC 598), spiral galaxy in Triangulum, is thought to be some 2.6 million light years distant — but that estimate may require further revision. Image credit: Adam Block / NOAO / AURA / NSF

Take a gander at today’s fascinating press release from Ohio State University:

An Ohio State University astronomer and his colleagues have determined that the Triangulum Galaxy, otherwise known as M33, is actually about 15 percent farther away from our galaxy than previously measured.

This finding implies that the Hubble constant, a number that astronomers rely on to calculate a host of factors — including the size and age of the universe — could be significantly off the mark as well.

That means that the universe could be 15 percent bigger and 15 percent older than any previous calculations suggested.

This development I’m guessing has raised some eyebrows, particularly among those with a much better grasp of cosmology than I. Notwithstanding, I think it fair to say that this finding is potentially big.

The Hubble constant - which describes the rate of cosmic expansion - is a crucial cosmological component, and has been a subject of rather passionate debate spanning many years. A number of ongoing observations have continued to refine its value, most notably of late those performed by the Hubble Telescope and the Wilkinson Microwave Anisotropy Probe (MAP, for short), whose latest results were released earlier this year. The European Space Agency’s upcoming Planck mission will also offer invaluable contributions in this area, as one of its key objectives is to determine the Hubble constant (and I’m eagerly awaiting its launch).

This team of astronomers plans on completing additional observations in order to repeat and refine their calculations, a process which will take a couple of years. It should be well worth the wait, and I’m very much looking forward to seeing what develops.

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Filed under: Astronomy, Science, Cosmology |

3 Responses to “A Bigger, Older Universe?”

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1 Wolverine on Aug 4th, 2006 said:

This New Scientist Space article on the subject hit the ‘net today.
2 Wolverine on Aug 7th, 2006 said:

And another this morning on Space.com. I’m surprised more commentaries haven’t been posted sooner… or perhaps I’m just geekier than average.
3 Wolverine on Aug 8th, 2006 said:

Today, the Chandra X-Ray Observatory has weighed in on the Hubble constant:

By combining X-ray data from Chandra with radio observations of galaxy clusters, the team determined the distances to 38 galaxy clusters ranging from 1.4 billion to 9.3 billion light years from Earth. These results do not rely on the traditional distance ladder. Bonamente and his colleagues find the Hubble constant to be 77 kilometers per second per megaparsec (a megaparsec is equal to 3.26 million light years), with an uncertainty of about 15%.

This result agrees with the values determined using other techniques. The Hubble constant had previously been found to be 72, give or take 8, kilometers per second per kiloparsec based on Hubble Space Telescope observations. The new Chandra result is important because it offers the independent confirmation that scientists have been seeking and fixes the age of the Universe between 12 and 14 billion years.