Rough Draft of Statement of Purpose Physics PhD

[micromass]

Catastrophe. The word invokes a feeling of discouragement and destruction.

Are you actually being serious right now?

 

[harmony5]

Are you actually being serious right now?

Are you actually being serious right now?

I saw an example SoP where someone started with the word perturbation and supposedly everyone said that was a really good one. So I figured I would do something similar.

 

[harmony5]

"My goal is to conduct theoretical research that is at the intersection of Cosmology and Particle Physics. Recent work to resolve the vacuum catastrophe such as the DGP model convinced me to pursue this path. In the same way resolving the ultraviolet catastrophe revolutionized physics, resolving this catastrophe may revolutionize physics again by radically changing our understanding of gravity and the dimensionality of space. Due to the vacuum catastrophe I feel Particle Cosmology is an exciting field to be part of as of today" Is this better?

 

[radium]

A statement of purpose is not the time to be dramatic. Who did you have read your statement? You want to be concise and too the point. It's not some creative writing piece.

 

[micromass]

I saw an example SoP where someone started with the word perturbation and supposedly everyone said that was a really good one. So I figured I would do something similar.

Who is "everyone"? The only people you should care about is the admission committee really.

 

[harmony5]

A statement of purpose is not the time to be dramatic. Who did you have read your statement? You want to be concise and too the point. It's not some creative writing piece.

Because I wasn't getting replies to this thread anymore I moved on to academia sub reddits for. They all said it was boring and I didn't talk enough about my research. I will say though that I trust this forum far more then any physics or grad school sub reddits. The perturbation part I got from a university Web site though.

 

[harmony5]

Who is "everyone"? The only people you should care about is the admission committee really.

The perturbation part was from a university website saying I need a strong hook.

 

[micromass]

So let's pretend I'm in your admission committee (I've never been in one so I wouldn't know, but hey). I see your record and your statement of purpose. I see on your record that you don't really have any experience with QFT and with GR. And I see in your statement of purpose that you want to go into precisely that field. This raises a pretty major red flag to me. You need to use your SoP to convince me that you are a qualified candidate and that my worry is unnecessary.

 

[harmony5]

So let's pretend I'm in your admission committee (I've never been in one so I wouldn't know, but hey). I see your record and your statement of purpose. I see on your record that you don't really have any experience with QFT and with GR. And I see in your statement of purpose that you want to go into precisely that field. This raises a pretty major red flag to me. You need to use your SoP to convince me that you are a qualified candidate and that my worry is unnecessary.

I just got an idea. I should emphasis how I knew nothing about Nonlinear dynamics when I began my research. But after three semesters I knew more about it then the professors in the department. Is that what you mean?

 

[harmony5]

@micromass do you feel that in my latest draft I went into to much detail about my research. I did that because I wanted to show how I was creative.

 

[Vanadium 50]

Look, we've given him (or her) the same advice, over and over. (S)he clearly doesn't want to take it. No point in giving it again. And again. And again.

Harmony5, best of luck to you.

 

[harmony5]

Look, we've given him (or her) the same advice, over and over. (S)he clearly doesn't want to take it. No point in giving it again. And again. And again.

Harmony5, best of luck to you.

Are you saying I have made no progress in my SoP.

 

[harmony5]

I do want to take everyones advice and I'm not here to waste anyone's time. I'm quite amazed how much difficulty I'm experiencing writing this. It's been three weeks and I went from a horrible SoP to a slightly less horrible one. Is it because I go into much detail about my research? Not enough detail. Is my research experience so bad that the more I talk about it the worse I look? Is it still unfocused? I know my last two renditions have been terrible but I don't know why

 

[Vanadium 50]

Are you saying I have made no progress in my SoP.

No, although the latest one is a step backwards. I am saying that you have gotten some good advice that you aren't taking. Starting at message #2. I don't see where repeating it will do any good.

 

[harmony5]

No, although the latest one is a step backwards. I am saying that you have gotten some good advice that you aren't taking. Starting at message #2. I don't see where repeating it will do any good.

The latest was a step back I understand. How about the one prior the latest. I know the 599 word one isn't good but I did model it on the advice you all gave me. To be clear it being bad was due to me misunderstanding all of your advice. My problem is Idk why that 599 word one in which I tried to not sound erudite Is still a abomination.

 

[atyy]

My background: I'm a biologist, and I wrote in my grad school essay I was interested in consciousness (which is way worse than anything you've written), so I'm not qualified. But what exactly is the vacuum catastrophe? In what sense is it a problem that QFT cannot predict the cosmological constant? After all, there are free parameters in the standard model too that we cannot predict. If one treats the cosmological constant as a free parameter, there is no deviation between theory and observation.

 

[harmony5]

My background: I'm a biologist, and I wrote in my grad school essay I was interested in consciousness (which is way worse than anything you've written), so I'm not qualified. But what exactly is the vacuum catastrophe? In what sense is it a problem that QFT cannot predict the cosmological constant? After all, there are free parameters in the standard model too that we cannot predict. If one treats the cosmological constant as a free parameter, there is no deviation between theory and observation.

Don't look back at previous drafts. They were rejected for a reason. Please look and ask questions about my current SoPs. According to QFT the energy density in a vacuum is one Planck unit. If we attribute this energy density in the vacuum to the acceleration of space we calculate the density should be 10^-120.

 

[atyy]

Don't look back at previous drafts. They were rejected for a reason. Please look and ask questions about my current SoPs. According to QFT the energy density in a vacuum is one Planck unit. If we attribute this energy density in the vacuum to the acceleration of space we calculate the density should be 10^-120.

I'm looking at the one in post #70?

My question is: what is the problem with the density being 10^120? Are there any observable consequences?

 

[harmony5]

I'm looking at the one in post #70?

My question is: what is the problem with the density being 10^-120? Are there any observable consequences?

The observable consequence is that this energy density of 10^-120 is caused a negative pressure in the vacuum of space. This negative pressure is driving the expansion. The problem is that we have no way to accurately predict this energy density. QFT which attributes this energy density to the constant creation and annihilation of virtual particles in the vacuum gives a answer 10^120 times greater.

 

[atyy]

The observable consequence is that this energy density of 10^-120 is caused a negative pressure in the vacuum of space. This negative pressure is driving the expansion. The problem is that we have no way to accurately predict this energy density. QFT which attributes this energy density to the constant creation and annihilation of virtual particles in the vacuum gives a answer 10^120 times greater.

Please state the predicted value of the energy density and the observed value.

 

[harmony5]

Please state the predicted value of the energy density and the observed value.

Predicted 1 Planck energy unit.

Observed 10^-120 Planck energy units.

 

[atyy]

Predicted 1 Planck energy unit.

Observed 10^-120 Planck energy units.

But are you taking into account that general relativity allows a cosmological constant, whose value can be fixed so that the effective energy density matches observation? So in the sense of a deviation between prediction and observation, there is no problem.

 

[atyy]

I made a Poincare sections simulation as this small parameter was increased. Interpreting the results in terms of the KAM theorem I observed invariant tori disintegrating. The manner in which their disintegrated though, was unusual. First, they collapsed into themselves to form periodic orbits. If the parameter was increased slightly further the collapsed tori exploded into a sea of points. I concluded I was observing an unexpected route to chaos. As this parameter starts off at zero and is increased the motion is quasiperiodic; it then abruptly becomes periodic and if increased further chaotic. None of the professors in my department observed this before and this became the most prominent result of my research. Deriving this result taught me how to use computational methods to bring the theory I'm studying to life.

This sounds interesting. Have you published it?

 

[harmony5]

@micromass , @Vanadium 50 @radium if any of you can answer this question I think I'll know how to write this. My biggest road block trying to keep this thing under 700 words but at the same time convincing the admission committee I had a profound research experience. Every time I try to talk about my research experience I always write to much. Because I write so much about my research experience I can't devote enough words to talk about other things. How should I describe my research experience?

 

[atyy]

@micromass , @Vanadium 50 @radium if any of you can answer this question I think I'll know how to write this. My biggest road block trying to keep this thing under 700 words but at the same time convincing the admission committee I had a profound research experience. Every time I try to talk about my research experience I always write to much. Because I write so much about my research experience I can't devote enough words to talk about other things. How should I describe my research experience?

Once again, I'm a biologist, so don't take me too seriously.

I think your essay presentation is getting better. I think your biggest problems were (1) talking enough about your own research to show that you did understand the technical details. But this is much improved by the detail in the version in post #70 (2) you would like to move to a new field, but your descriptions of research in that field seem very inaccurate, making it doubtful that you understand even the problems in that field. For example, your description of the vacuum catastrophe problem seems wrong. Your statement of the Weinberg-Witten theorem in response to an earlier question of mine is also wrong.

Edit: Competition will probably be tough, because you have had no experience with QFT. Most of my physics friends who went on to do quantum gravity research did QFT before applying to grad school. So it doesn't help if by stating the problems inaccurately or at the level of a popsci book or less, you show that you really don't know any QFT. You need to at least understand enough QFT to state the problems accurately.

 

[harmony5]

Once again, I'm a biologist, so don't take me too seriously.

I think your essay presentation is getting better. I think your biggest problems were (1) talking enough about your own research to show that you did understand the technical details. But this is much improved by the detail in the version in post #70 (2) you would like to move to a new field, but your descriptions of research in that field seem very inaccurate, making it doubtful that you understand even the problems in that field. For example, your description of the vacuum catastrophe problem seems wrong. Your statement of the Weinberg-Witten theorem in response to an earlier question of mine is also wrong.

Edit: Competition will probably be tough, because you have had no experience with QFT. Most of my physics friends who went on to do quantum gravity research did QFT before applying to grad school. So it doesn't help if by stating the problems inaccurately or at the level of a popsci book or less, you show that you really don't know any QFT. You need to at least understand enough QFT to state the problems accurately.

I'm not trying to show off my knowledge of QFT or Quantum Gravity in my SoP. All I want to show is that I can translate the success I had in conducting research in nonlinear dynamics to this new field. http://ezproxy.library.nyu.edu:4285/content/aapt/journal/ajp/63/7/10.1119/1.17850 someone more qualified then both of us saying it is a problem.

 

[harmony5]

"Quantum field theory predicts a very large energy density for the vacuum, and this density should have large gravitational effects. However these effects are not observed, and the discrepancy between theory and observation is an incredible 120 orders of magnitude. There is no generally accepted explanation for this discrepancy, although numerous papers have been written about it. "

 

[atyy]

"Quantum field theory predicts a very large energy density for the vacuum, and this density should have large gravitational effects. However these effects are not observed, and the discrepancy between theory and observation is an incredible 120 orders of magnitude. There is no generally accepted explanation for this discrepancy, although numerous papers have been written about it. "

I can't access the link you gave. However, it is inaccurate in the sense that the cosmological constant can be fixed to remove the discrepancy between the naive prediction and observation. Here are two references:

(1) Arkani-Hamed, Why is there a macroscopic universe?
http://www.cornell.edu/video/nima-arkani-hamed-why-a-macroscopic-universe (15:30-17:00)

(2) Shapiro and Sola, Cosmological Constant Problems and Renormalization Group
http://arxiv.org/abs/gr-qc/0611055v2

The problem is not a discrepancy between theory and prediction. Rather the problem is one of "fine-tuning". Is fine-tuning a problem? It is hard to argue conclusively that it is, but if there is an argument against fine-tuning, then it is best stated in the language of the Wilsonian view of the renormalization group. The Wilsonian renormalization group is conceptually important, because although most QFT textbooks teach it late, it is simple and allows us to say we "understand" renormalization: http://quantumfrontiers.com/2013/06/18/we-are-all-wilsonians-now/.

 

[radium]

Why are you having people on reddit and here to read your statement? You should be asking your recommenders and older peers who have been accepted to grad school from your department.

"I should emphasis how I knew nothing about Nonlinear dynamics when I began my research. But after three semesters I knew more about it then the professors in the department. Is that what you mean?" Don't put anything like this in your statement. Not only is this very arrogant, it is almost definitely false. People who say these types usually do so because they do not know enough about whatever topic to know what they don't know, something like the Dunning Kruger effect.

 

[harmony5]

Why are you having people on reddit and here to read your statement? You should be asking your recommenders and older peers who have been accepted to grad school from your department.

"I should emphasis how I knew nothing about Nonlinear dynamics when I began my research. But after three semesters I knew more about it then the professors in the department. Is that what you mean?" Don't put anything like this in your statement. Not only is this very arrogant, it is almost definitely false. People who say these types usually do so because they do not know enough about whatever topic to know what they don't know, something like the Dunning Kruger effect.

Well given the current state of it I would be embarrassed to show my professors to be honest. It is indeed a mess. Quite possibly even the latest renditions are the worst SoP ever written on this forum. I would like to get a acceptable SoP first before I bringing it to my professors. Your right that is a massive hyperbole. But the gist is that I should emphasis I knew nothing about Nonlinear dynamics when I began my research. But after three semester I knew enough about nonlinear dynamics to successfully conduct research in it and the same will be of Cosmology and Particle physics.

 

[radium]

Well maybe instead of giving your recommenders the current draft of your statement of purpose, you should ask them for advice in general.

 

[harmony5]

After rewriting my SoP a lot of times I think I have finally completed a draft which is quite good. I hope you all agree and if not please tell me why.

"

My purpose in life is to expand our body of knowledge of how the universe operates. To realize this purpose my goal in graduate school is to conduct theoretical research that is at the intersection of Cosmology and Particle Physics. Some topics I would like to further explore are cosmic inflation, the expansion of the universe and the effects of modified gravity. These phenomena and problems compel me because they have profound implications for all observed length scales in physics.

To achieve this goal I want to perform research at the Center for Cosmology and Particle Physics. I’m attracted to the the CCPP because the creators of the DGP model are there. It was this model, and others in modified gravity, that convinced me to pursue Particle Cosmology due to their sheer creativity. Currently I would like to work with either Professor X or Y. Professor X's work on large, extra dimensions interests me because it can answer a question I always had: why is K so much larger than G? I also would be interested to be part of Professor Y's research on distinguishing between modified gravity and dark energy. After completing graduate school, I eventually want to become a professor of physics.

As an undergrad, I honed my mathematical modeling and research skills by working with Professor V of the Applied Physics Department in nonlinear dynamics. At the start, I knew nothing about nonlinear dynamics or numerical methods. However, through self study in a few weeks, I learned Mathematica and was familiar with the field. My job was to model the motion of a Physical Double Pendulum we built in the lab and discern its route to chaos. Using Lagrangian Mechanics and Rayleigh dissipation functions, I created a model to match its motion. I couldn't continue this research due to difficulties in attaining a high camera for future use. In hindsight, I would have treated our model pendulum as a system with three degrees of freedom, because it oscillated when it rotated, and treated the support to which it was attached as an energy sink. This third degree of freedom would be a harmonic oscillator, that drew energy away from the other two.

After finding a parameter (which if set to zero) made the system integrable, I created a Poincare sections simulation and observed that, as the parameter increased, the KAM invariant tori disintegrated in an unusual way. They collapsed into themselves to form periodic orbits and if increased slightly further exploded into a sea of points. As this parameter starts off at zero the motion begins as quasiperiodic; it then abruptly becomes periodic, and if increased, further chaotic. I concluded I was observing an unexpected route to chaos. While doing research I learned much of the advanced mathematics of classical mechanics. This math included SU(2) symmetry, Birkhoff Gustavson perturbation theory, Lie Algebra, topology and some differential geometry. The mathematics I learned aided me in interpreting my results and give me a strong foundation to learn and conduct research in other fields of physics.

In college, I took and passed three graduate physics classes including Professor Z's dynamic class. Taking these classes prepared me to complete the required course work of graduate school so I can proceed afterward to conduct research. Even though I learned plenty of technical skills as an undergrad, the most important thing I learned was how to persevere through tragedy and stress. Tragically, in the spring of 2015 my father died. Despite the emotional distress, I completed 29 credits of coursework to graduate on time while working two jobs and conducting research. My undergraduate experience prepared me to overcome any challenge whether it be academic or personal. Using my technical skills and the shown ability to persevere to get the job done I’ll pass the required classes and succeed in conducting research at the frontier of physics."