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Dr Kathy Romer answers your questions about Physics!

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Reply 20
Can you just explain the whole of Magnetic Fields in general please? AQA PHYA4
Reply 21
Original post by Protoxylic
Thanks for tagging. Right now I study Physical NatSci at Cambridge and I (quite obviously) took Physics at A level (AQA). I'm Happy to answer any questions about Physics, Chemistry, Maths at A-Level and at University additionally I'm open to answer any questions specific to Science at Oxbridge.


Is there a way of actually learning the transition metals in CHEM5 by using knowledge and application rather than memorising the equations with ligands?
What is dark energy? How does this theory link to the expansion of the universe?

AQA A2 PHYA5 Astrophysics Exam
Original post by dnan
Is there a way of actually learning the transition metals in CHEM5 by using knowledge and application rather than memorising the equations with ligands?


Colours, no. In general I found there wasn't any particularly easy way to understand fully what was going on, at least on a fundamental level.

Transition metal theory is a complicated area and it isn't even covered here at Cambridge until second year onwards. I feel that the transition metals unit at A-Level is less of a theoretical unit and more of an introduction into what transition metal complexes are, some limited theory on why they are coloured and a small area on the thermodynamics of chelation. In terms of fully understanding the bonding that goes on in terms of the interactions involved as well as the shapes adopted is something that isn't covered at A-Level.

For the equations, general understanding on how to balance equations (particularly half equations) in both acid and base is useful, i.e recognising that you can add water or OH- to either side of an equation to balance them for charge or oxygen. General knowledge that higher oxidation state ligands are stabilised in base (this is just an argument of charge stability) and vice versa. Those should keep you comfortable in the exam, there isn't much more they can ask.
Reply 24
what is the use of a split ring commutator and brushes AQA GCSE
Reply 25
Original post by Protoxylic
Colours, no. In general I found there wasn't any particularly easy way to understand fully what was going on, at least on a fundamental level.

Transition metal theory is a complicated area and it isn't even covered here at Cambridge until second year onwards. I feel that the transition metals unit at A-Level is less of a theoretical unit and more of an introduction into what transition metal complexes are, some limited theory on why they are coloured and a small area on the thermodynamics of chelation. In terms of fully understanding the bonding that goes on in terms of the interactions involved as well as the shapes adopted is something that isn't covered at A-Level.

For the equations, general understanding on how to balance equations (particularly half equations) in both acid and base is useful, i.e recognising that you can add water or OH- to either side of an equation to balance them for charge or oxygen. General knowledge that higher oxidation state ligands are stabilised in base (this is just an argument of charge stability) and vice versa. Those should keep you comfortable in the exam, there isn't much more they can ask.


Balancing equations aren't the problem, it's remembering the colours and which continue reacting when standing in oxygen and which stay the same. I struggle to just memorise stuff i need to understand the theory behind it, but this topic seems to be just memory which is the oppisite of what a levels are supposed to be.
Original post by Dr Kathy Romer
Hello.

The normal route into an academic career in Physics is: PhD, then 2 or 3 postdocs, then a lecturership. If you can get an independent fellowship then you could go PhD to fellowship to lectureship, especially if it is a 5 year fellowship. But there are other routes that include detours via high school teaching, industry, entrepreneurship, parenting/caring etc. Physics is a very open minded discipline. Age; gender or sexual orientation; educational, ethic or economic background are not important. Indeed species is not relevant either: we'd be more than happy to welcome those from other worlds, if it helps us solve the mysteries of the Universe quicker!

WRT: How do you think more women can become interested in Physics at A Level and beyond..... Taking the "beyond" first: in my experience (and having looked at some of the data available, e.g. from IoP), once a female sixth former is taking Physics then her chances of doing it at Uni (and beyond) are not much lower than her male counterparts. Indeed in my own case, I started my A'levels assuming I'd go into medicine, but exposure to A'level physics was enough to divert me from that path.
How to get more Y11 girls interested in taking Physics at Alevel is harder. One thing I think is crucial is making sure that Y7 and Y8 girls are given lots of encouragement to take triple science at GCSE. One a child opts for double science, its pretty much game over for Physics A'level (more because of the "friends group" pressure than because double science doesn't provide a quality education).
So IMHO the key is to ensure Y10 and Y11 girls (and boys of course) have the opportunity to see Physics as the coolest of the three sciences (and it won't be for "coolest" for everyone: it vital that some of our brightest kids to see Biology, Chemistry, Maths, Computing, or Drama, Art etc, as the coolest). And what makes a subject cool? Teachers.

Teachers are the superheroes of our society. Let's pay them more, give them longer holidays, and give them more time to be creative and to undertake professional development. Hats off to the government for encouraging Physics graduates into teaching through their various bursary schemes: the money is nice but what is persuading our Physics students at Sussex to going into teaching in ever increasing numbers is the fact that the teaching profession is held in high esteem.




Hi,


I know this question might be placed in a better section of the student room, but


How do you find funding for a Phd, and what would you need to gain access to do a Phd ... do you need the full 4 years masters or can you go from a 3 year one to do a Phd ?


Cheers,


Will
Original post by dnan
Balancing equations aren't the problem, it's remembering the colours and which continue reacting when standing in oxygen and which stay the same. I struggle to just memorise stuff i need to understand the theory behind it, but this topic seems to be just memory which is the oppisite of what a levels are supposed to be.


I mean the theory behind why things are coloured is covered as a general concept, but to ask the question 'Why copper III hydrate is blue' is just because it is, otherwise you'd have to attempt to remember the wavelengths of light and what their respective colours are. So the colours themselves are a memory test. As to which continue to 'react' is another vague question which you need to just take as granted. You can rationalise why certain things happen in Chemistry, but it is extremely difficult to predict correctly what definitely will happen. You can use intuition to rationalise why given things happen. You'd have to give me an example of a question that you would find difficult for me to fully answer your question.
Original post by King_Kauko
What is dark energy? How does this theory link to the expansion of the universe?

AQA A2 PHYA5 Astrophysics Exam




I see it as, well no one really no knows. But as the universe is expanding the velocity is increasing, and there must have been a force to increase its velocity in a given time frame ( F=ma) .... I am not sure you could use that idea, but it seems to work


Anyway dark energy is what is suggested that causes this 'force' but thats all you need to be aware of for the exam .


Though from hearing about the C3 exam from AQA I am sure they will be asking for a paper on it.


ah :wink:
Original post by John Fluffy Bunny
Why is the discovery of gravitational waves considered to be so significant? What are the possible uses/applications of them in real life?


Why so significant?

Great Question!!

There are several aspects to this. I think the most important one is that is a testament to the tenacity of human endeavour. We (humans) wanted to prove something to be correct, so we pushed the technology and formed international collaborations and, most importantly, never gave up. Another example that has the same transformative feeling of humans making the impossible possible was the confirmation of the theoretical predicted fluctuations in the Cosmic Microwave Background by the COBE satellite in 1990. And there are several other (in the handfuls rather than hundreds) of similar examples.

For this reason, it was always going to be the first confirmed GW detection that was always going to be the most significant.

Another important aspect to the first detection is what it is telling us. The concepts surrounding general relativity, black holes etc. are by now so established both in the scientific world and in popular culture that you might think that supporting evidence for them is two-a-penny. But that isn't the case. I remember waking up the day after the big announcement of the first discovery and found myself profoundly depressed. Not because I was unhappy that it had been discovered but because the Universe is suddenly less mysterious. I hadn't realised how much I loved the mystery. [BTW, as far as I know I am the only physicist who felt like that!]

OK, so if the first discovery gave us the "wow, that really expensive, really complicated machine actually works", and "wow, those theories are indeed correct", what do the discoveries announced yesterday and that (fingers crossed) will be announced every month or so from now on, give us?

What they give us are new mysteries. Maybe not such profound ones, but cool all the same. For example, we've moved on from "do star sized black holes actually exist?" to "how many star sized black holes are there, and what are their properties?".

GW research a complex subject and not one that I am an expert in (my field is X-ray Astronomy). But if I was starting my PhD career now it is definitely a field I'd be drawn to. I introduce myself as an Astronomer, but I am first and foremost a Physicist. I use what we can measure outside our own planet to do my Physics. In my view, the closer the observations get to the Physics the better. And you can't get much closer to the Physics than measurements of Gravitational Waves!

Q What are the possible uses/applications of them in real life?

That's easy to answer! NONE!

Instead, it is worth considering the fact that the scientists and engineers who made LIGO work have pushed technology to its limits. They have made the impossible possible. Humans don't tend to push that hard to do something that difficult unless they are driven. And fundamental questions about Physics are a very powerful driver. The internet wouldn't have happened without particle physics. I can't predict what transformative spin-out technology will come out of LIGO, but I am sure there will be some.
Original post by Dr Kathy Romer
Hello.
Physics is a very open minded discipline. Age; gender or sexual orientation; educational, ethic or economic background are not important. Indeed species is not relevant either: we'd be more than happy to welcome those from other worlds, if it helps us solve the mysteries of the Universe quicker!


Haha, and thanks for answering! :smile:
I'm really interested in Physics but still want to study Medicine, and I was wondering: what are, in your opinion, the most important and exciting things where those two overlap? I'm obviously familiar with the medical uses of radiation, but I was wondering if there maybe are some new intriguing theories about the links of Physics and the human body.

Thank you for your time, it's great to have you here!
Original post by Billsonbubbles
Hi,


I know this question might be placed in a better section of the student room, but


How do you find funding for a Phd, and what would you need to gain access to do a Phd ... do you need the full 4 years masters or can you go from a 3 year one to do a Phd ?


Cheers,


Will


I'm not sure if you are an undergraduate or still in school/college. I'll assume the former in this reply, and give general information. (But, if you already at Uni, you can get specific information from your department careers tutor and from your central careers service. If you are in Physics, then make use of all the great info available from IoP.)

PhDs in science are usually funded by the government's research councils. They can also be funded by charitable organisations. Individual Departments quite often fund PhDs directly. Funded PhD students do not pay fees and they receive a tax free stipend of £14K per annum.

Most PhDs are open to applications from anyone with a two-one at BSc. However, in practice, demand is usually high enough that a First in an MSci/Phys (if your degree has a 4 year version) is the norm.
Original post by King_Kauko
What is dark energy? How does this theory link to the expansion of the universe?

AQA A2 PHYA5 Astrophysics Exam


Dear King_Kauko, thanks for your question!

Dark Energy is huge subject, and one of my favourites! I will reply with more info another day, but its getting late, so I'd like to recommend the public outreach materials we have developed for the Dark Energy Survey:

http://www.darkenergysurvey.org/

https://www.facebook.com/darkenergysurvey

@theDESurvey

There is also a nice article in the Mail Online this week where I'm quoted explaining dark energy in lay terms.

http://www.dailymail.co.uk/sciencetech/article-3640755/The-alien-hunting-robots-Machines-probe-secrets-universe-studying-distant-galaxies-start-tests-month.html
Reply 34
I'm an aspiring Physics student who's going to read Theoretical Physics this September. Can you give me any tips and tricks that were proven to be effective for you that I'd need in coping with the undergraduate course?
I've another question that I've always wanted to ask out of my own curiosity and has nothing to do with my exams.
If an object with mass interacts with the surrounding gravitational field, then why are photons affected by gravity considering that they're massless particles? And since neutrinos have very little mass, why aren't they affected by gravity?
Reply 35
Hi, and thanks for taking our questions!

Just wondering whether you could explain gyroscopic motion in a way which is understandable.. All resources I've found online go a bit too far into theory/complicated explanations.
Original post by Protoxylic
Colours, no. In general I found there wasn't any particularly easy way to understand fully what was going on, at least on a fundamental level.

Transition metal theory is a complicated area and it isn't even covered here at Cambridge until second year onwards. I feel that the transition metals unit at A-Level is less of a theoretical unit and more of an introduction into what transition metal complexes are, some limited theory on why they are coloured and a small area on the thermodynamics of chelation. In terms of fully understanding the bonding that goes on in terms of the interactions involved as well as the shapes adopted is something that isn't covered at A-Level.

For the equations, general understanding on how to balance equations (particularly half equations) in both acid and base is useful, i.e recognising that you can add water or OH- to either side of an equation to balance them for charge or oxygen. General knowledge that higher oxidation state ligands are stabilised in base (this is just an argument of charge stability) and vice versa. Those should keep you comfortable in the exam, there isn't much more they can ask.

What edexcel math units do you need for the PAT, I know you need core but people say the syllabus is very vague and hey bring things required form other units
Currently finished c1c2m1
Original post by Mahrez
what is the use of a split ring commutator and brushes AQA GCSE


Hello Mahrez, I hope you've already stopped revising, since the exam is tomorrow morning. But, as it happens, I've just been discussing this topic with my son - he took a rather extended break from his revision to watch the England game!

If you look at
http://www.bbc.co.uk/schools/gcsebitesize/science/triple_aqa/keeping_things_moving/the_motor_effect/revision/4/

There is a nice video that shows how the splits temporarily stop the current flowing. But the ring keeps turning because it has angular momentum. When current flows again its direction is reversed inside the ring and so the forces remain in the same direction.
Hi there,

I was wondering what your opinion on A-level physics is (OCR specifically).
Do you or do you not think that the A-level tests study a student's ability in physics/maths, or is it more of just remembering lines for the exam?

Lately I've had trouble finding motivation to revise for my A2 physics exams, especially unit 5 where the majority of it is just remembering standard answers - not the greatest thing I find fun to do.
Do you have any tips on how to sit down and study for topics/ styles of questions for physics that you don't like?

Also, is a career in academia rewarding, both financially and mentally?
Original post by Dr Kathy Romer
Why so significant?

Great Question!!

There are several aspects to this. I think the most important one is that is a testament to the tenacity of human endeavour. We (humans) wanted to prove something to be correct, so we pushed the technology and formed international collaborations and, most importantly, never gave up. Another example that has the same transformative feeling of humans making the impossible possible was the confirmation of the theoretical predicted fluctuations in the Cosmic Microwave Background by the COBE satellite in 1990. And there are several other (in the handfuls rather than hundreds) of similar examples.

For this reason, it was always going to be the first confirmed GW detection that was always going to be the most significant.

Another important aspect to the first detection is what it is telling us. The concepts surrounding general relativity, black holes etc. are by now so established both in the scientific world and in popular culture that you might think that supporting evidence for them is two-a-penny. But that isn't the case. I remember waking up the day after the big announcement of the first discovery and found myself profoundly depressed. Not because I was unhappy that it had been discovered but because the Universe is suddenly less mysterious. I hadn't realised how much I loved the mystery. [BTW, as far as I know I am the only physicist who felt like that!]

OK, so if the first discovery gave us the "wow, that really expensive, really complicated machine actually works", and "wow, those theories are indeed correct", what do the discoveries announced yesterday and that (fingers crossed) will be announced every month or so from now on, give us?

What they give us are new mysteries. Maybe not such profound ones, but cool all the same. For example, we've moved on from "do star sized black holes actually exist?" to "how many star sized black holes are there, and what are their properties?".

GW research a complex subject and not one that I am an expert in (my field is X-ray Astronomy). But if I was starting my PhD career now it is definitely a field I'd be drawn to. I introduce myself as an Astronomer, but I am first and foremost a Physicist. I use what we can measure outside our own planet to do my Physics. In my view, the closer the observations get to the Physics the better. And you can't get much closer to the Physics than measurements of Gravitational Waves!

Q What are the possible uses/applications of them in real life?

That's easy to answer! NONE!

Instead, it is worth considering the fact that the scientists and engineers who made LIGO work have pushed technology to its limits. They have made the impossible possible. Humans don't tend to push that hard to do something that difficult unless they are driven. And fundamental questions about Physics are a very powerful driver. The internet wouldn't have happened without particle physics. I can't predict what transformative spin-out technology will come out of LIGO, but I am sure there will be some.


Awesome, thanks for such a detailed answer!

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