Accelerating expansion of the universe

If I understood I'd respond

Where is everyone else

What do you mean

If I understood I'd respond: If I were a cosmologist I'd answer to "what the scientific concensus actually is"

Where is everyone else: Why aren't others responding

Sorry, i dunno : my first post, wasnt even sure whether i would get a response

Yes, no, Che, it's pretty technical

You might consider condensing it with everyday language for the Average Clod (me)

Your thinking is ok but your facts are bit off. First, the universal gravity constant G is not changing. The reason for the accelerating expansion is not because of a weakening gravity but because of dark energy, which provides a force against gravity. Before dark energy was confirmed it could have been that expansion was increasing because of a weakening gravity force. It is now known that it is because of dark energy.

The fields in particle physics are infinite entities so there is no need for anything to “stretch”. The Higgs field exists at every point in space.

You cannot assume that if a field is “stretched” (if possible for the particular field) that this would mean a reduction in the effect of the field. In fact for fields with asymptotic freedom the more force used against the field the greater the field strength becomes – to infinity.

This is how the strong force works. While you are not stretching the field, when you attempt to separate the quarks in a nucleon, the farther you pull them apart the stronger the strong force becomes. It is not possible to completely separate them.

The concept of the Higgs field can be bit difficult to discuss as there is a good bit of information one needs to have it make much sense. For example what the Higgs field actually does is to break what is known as Yangs-Mills symmetry. The Yang-Mills field is a basic multi-component field (24 component fields). In breaking this symmetry it causes fermions to gain mass but not gluons as they are not affected by the Higgs field. As you can imagine that leaves out a LOT of detail.

It is also interesting to note that the concept that Higgs had was first seen as only providing a mathematical process that allowed deep analysis of Yang-Mills and other “gauge” symmetries. It was only later that it was determined that the concept could be used to answer one of the most fundamental questions in physics: where does mass come from?

As this is your first post I would point out the “Ask the Experts” is a marketing label not a true evaluation of the type of responses you can expect here.

I think it's time to update the sig line, Zarathustra.

Yea Zara, G was the first puzzlement as I hadn't heard that it changes either

Excellent, thank you. I now have a place to start, i was finding it difficult trawling through info on the web. Btw where should i be asking questions if not here?

If this site fit your needs, fine. It is just that the site shows up on Google searches with the tag line I noted in the previous post. There are some sites that do provide answers by credentialed posters and I just didn’t want you to wait around for a cosmologist to answer your questions, here.

It can be frustratingly difficult to find information on the web, so I can sympathize with your problem.

so when you say that its dark energy, does that mean that dark energy is actually increasing? it has to doesnt it?, in order to achieve an acceleration in the expansion of the universe, rather than an equilibrium with no resultant.

I would say the best answer is we don’t know yet. It has only been recently that we have obtained the first real measurements of dark energy. So astronomers are still trying to figure out “how much” dark energy there is. The source of the energy, its characteristics, and history, will come later -- perhaps.

Again, your conclusion makes sense but until we know more I don’t know if it is correct. For example, you get into your car and accelerate down the road hitting 60km/h. You come to a steep hill and your acceleration and velocity increase, was this caused by an increase in the energy expended by the engine? No. It was the hill. It could be something analogous to this in terms of dark energy. It may be a steady dark energy but some other change that is causing the increase in the rate of expansion. We currently know so little.

Hmmmm interesting. Can I ask? Are you a scientist/ have you studied physics? Or are you just someone who takes an interest?

One of my degrees is in “science”, in what used to be called physical chemistry (this is differentiated into many sub-fields today). I worked in the field directly for about 5 years. I now occasionally require this knowledge on some projects but mostly don’t use the knowledge very often anymore.

My knowledge of astronomy comes from being an amateur astronomer. It allows me to try of keep up on developments in addition to doing observations. My basic grounding in science certainly helps with the hobby.

Wow. I can’t tell you the thrill of having one of the A2K old guard actually use the valuable piece of real estate that is a signature line to rag on me, an A2K nobody. I haven’t been this honored since I was next to the stage at a Linda Ronstadt concert and from time to time her spit would hit me when she sang. “This is the kind of publicity, my name in print, that makes people.”

In a true and just world, sir, you would be King!