Globular Clusters... so old!

[Kropster]

I was taking a look at M13 a few nights ago when I started chasing a satellite that went through the finder field of view.

As I followed it across the sky, I came across a fuzzy blob.... looked it up and found it was M92.

Was astonished to read that this globular cluster is about 14.1 billion years old....practically the same age as the universe!

Totally amazing.

What I wonder, is why they don't collapse inwards under the gravity from all the stars?

[Pig]

I think they are all still quite a long way apart from each other, in addition they have evolved that way and now physics are keeping them in their place, for now

[buzzc150]

Isn't the universe 13.8 billion years old at the last count ? Quite an achievement to be 300 million years older than the universe itself !!

[Mutley]

I'd guess they don't collapse because they are spinning - same as galaxies?

[estwing]

Isn't the universe 13.8 billion years old at the last count ? Quite an achievement to be 300 million years older than the universe itself !!

...that's this one...what about the other one's we've yet to discover?

[Knight of Clear Skies]

Isn't the universe 13.8 billion years old at the last count ? Quite an achievement to be 300 million years older than the universe itself !!

Looking up M92 on Wikipedia, its age is listed as "14.1 Billion years, +/- 1.2 Billion years". Most astronomical measurements are estimates, whenever I see a distance, mass or size I mentally add or thereabouts. Most globular clusters are very old, because very large molecular clouds were more common in the early universe. In the current epoch, a significant fraction of the star-forming material has been converted into stars.

What I wonder, is why they don't collapse inwards under the gravity from all the stars?

For the same reason that the planets don't fall into the sun. Newton used an imaginary cannonball to explain this. The principle is the same in a cluster: the individual stars orbit the centre of mass on average, although the paths they can end up taking meandering paths due to close encounters with other stars.

[Kropster]

I was going by Wikipedia for the age.

Strictly speaking then, as a globular cluster (of stars) it is of a later date, but originated as a gas cloud approx. 14.1 billion years ago.

As the stars orbit the centre of mass, the rotation period of the cluster can presumably be detected by observing the movement of the stars within the cluster?

[mdstuart]

I am sure that soon there will be a breakthrough and suddenly we will find we were hopelessly wrong and the universe will turn out to be 100s of billions of years old..

Just love those globulars! Try NGC 5934 in the Dolphin for a different experience with these objects..

Mark

[Stargazer_00]

I don't think that what we see as the universe is all there is to be honest. I believe that the big bang happened and that everything we see came from that, I just dont think that is all there is. I think the big bang was just like some gigantic supernova event and it and everything that came from it is just one thing in a much larger space.

If you imagine our entire universe coming from the big bang as comparable to a single star going supernova, that's kind of the way I see things. By this rationale I believe if you travelled for long enough you could escape our verse, travel the interverse space wtithin which probably nothing at all exists apart from distance and arrive into another verse.

[cotterless45]

Multiverse matey, certain that sometimes I'm in the wrong one.

It's where keys and odd socks go when they get lost,

Nick.

[avtaram]

Stargazer-00 I have been thinking along similar lines to you recently.

I believe there are probably an infinte number of universes all at different stages of development.

Avtar

[Knight of Clear Skies]

I am sure that soon there will be a breakthrough and suddenly we will find we were hopelessly wrong and the universe will turn out to be 100s of billions of years old..

That is very unlikely, as an age of the universe in the ballpark of 14 billion years is supported by multiple lines of independent evidence. If the universe was, say, 100 billion years old we'd see objects such as very cool white dwarfs, low-mass red giants and red dwarfs with very high abundances of helium, none of which have been observed.

[Qualia]

I am sure...the universe will turn out to be old[er]..

That is very unlikely, as an age of the universe in the ballpark of 14 billion years is supported by multiple lines of independent evidence.

Although I agree that we ought to adobt a willingness to act on the best hypothesis that we have the opportunity to form, I think we also need to adobt a more critical attitude. Science is provisional; it is science because of its very tentativeness. To a very real degree it has been science and modern philosophy that has shuffled human thought from absolutes of fixed eternity, to the modern realm of multiple, indeterminate, historically relative ones.

The view that one does not know for certainty is consistent with the idea that it makes sense to strive to know. The ideal has nothing to do with not having strong opinions, merely the humility to appreciate one’s own and other’s fallibility, that in any given case there is often a preponderance of evidence supporting the probability of one position other than another, but no more.

In this light, perhaps the existence of Red Galaxies may reveal more than our surrent theories suggest or allow for regarding the age of the universe

[Stargazer_00]

This part made me laugh

"To overcome this problem, a sophisticated technique called "Nod and Shuffle" was used..."

Ah the good old nod and shuffle. I use that when the wife is talking to me and it's clear outside, nod profusely whilst shuffling towards the back door.

[Knight of Clear Skies]

Although I agree that we ought to adobt a willingness to act on the best hypothesis that we have the opportunity to form, I think we also need to adobt a more critical attitude. Science is provisional; it is science because of its very tentativeness.

I think we're mostly on the same page, notice I said very unlikely rather than impossible. In this particular case the evidence strongly backs up the theory. For a universe about 13.8 billion years old no stars under about 0.85 solar masses should have left the main sequence, which is what we observe. It's a great victory for science that we can put an age on the universe with a high degree of confidence, and one well worth celebrating. However, it's equally important to recognise the many gaps and uncertainties in our theories.

[Kropster]

I read the comments after the article on the Red Galaxies and somebody observed that the article is some years out of date and more recent observations tie in with current theory quite well.

I think there may be a journalist recycling old news somewhere.

[Superdavo]

They are in orbit, so they can't just fall in, though some 'core collapse' globulars have sort of collapsed, and most stars are locked in tight orbits around the centre

[Kropster]

Wikipedia is good for an explanation... look up 'globular cluster'... it explains core collapse and depopulation by ejection from the core etc..