Recent content by willidietomorrow

I'm primarily interested in getting the jist of what is meant by that. The way I came across was in a philosophy of physics seminar where the topic was briefly mentioned.

For example, this wikipedia page CGHS model - Wikipedia mentions " In 2+1D, general relativity becomes a topological field theory with no local degrees of freedom, and all 1+1D models are locally flat."

Hi sorry, you're right. I usually hear discussions about local degrees of freedom when talking about gravity and string theory, so I naively thought I might post it here. I'm not exactly sure what category in the forum might my question best.

When physicists talk about a theory having local degrees of freedom, what is exactly meant by that statement? What are examples of theories with local degrees of freedom and what are examples of theories with no local degrees of freedom?

Homework Statement So I have got the question below. I am asked to find the phase difference between the electric field and magnetic field of electromagnetic waves traveling in a plasma, using the electrical conductivity expression. Now I have found the frequency of the waves and I know that...

Well I was thinking just to look at the amount of Fe3+ ions reduced by the zinc (assuming that only Fe3+ ions will be reduced to Fe2+).

Hmm why is not possible to determine the Fe3+ ion directly, isn't the reaction with zinc suppose to help with that?

Alright, so I know the amount of Fe2+ and can also determine the amount of fe3+ using zinc. So I can do (amount of Fe2+) / (amount of Fe2+ + amount of Fe3+) *100. Would that be a correct procedure?

Well, since I know the amount of dichromate I can find the amount of Fe2+ ions that reacted (dichromate x 6), so the titrated solution will only contain Fe3+ ions.

Titrating the original solution against Cr2O72-, I will find the amount of Cr2O72- I need to convert all Fe2+ ions into Fe3+ ions. Also titrating against zinc will give the amount of Fe3+ ions in the solution.

Yes, sorry that was a mistake. I changed the equation.

Hi I am stuck on the following question. Outline a plan of an experiment to determine the percentage of iron present as iron(III) in a solution containing Fe3+(aq) and Fe2+(aq) ions. You are provided with zinc, a standard solution of potassium dichromate(VI) and dilute sulphuric acid. Zinc can...