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Experimental physics: A long time hate has become the love of life!

  1. Jun 26, 2014 #1
    Hello everyone,

    i return to complete the final year of my degree in the next 12 months and go on to do further studies ie masters and phd depending on how long they will put up with me and all of my questions.

    I have had quite a long break, and have been continuing to study pure mathematics whilst away, but now that i have decided to go back, i want to attack my biggest weakness, experimental physics.

    During my degree, being quite naturally good mathematically (hence in theoretical physics) i was able to "fudge" my way through practical assessments by means of simply submitting experimental data which i knew was to be expected in each week's assessment, of course with believable uncertainties and commentary throughout the experimental report, in the format requested. I am not proud of this, and at the time, my ego prevented me from admitting to the post grads that i worked under that i struggled with a huge anxiety and fear of electricity and anything "hands on" in general.

    Over the past 6 months i have slowly gained a basic level of confidence with experimentation, and have really started to enjoy myself now that i realize it is not so bad as i thought it to be, and i have corrected a number of imbarassingly illogical methodologies which made me afraid of even attending practical assessments during the first 4 years i attended university.


    I am currently at home and have access to a wide range of industrial tools and electronic/computer scraps, so i will briefly bullet point the skill set i am currently building up, and would appreciate any recommendations and additions to this list from anyone with a high level of experience experimentally, im sure you will get an idea of what fields of physics my interests apply to or be able to suggest paths of possible interest:

    1) programming and customization of microprocessors and the implementation of the various sensors used to gather data

    2) integration (1) into the physical schematics of the kinds of experiments i expect to be conducting

    3) designing & constructing mechanical systems for which are intended to be able to both accurately measure, safely contain, and regulate the thermodynamic and electrical variables of liquid-vapour-gas-plasma ( in seperate chambers according to phase for analysis of various families of materials) . My aim or intent of design is to have these systems capable of withstanding RAPID (t) thermodynamic flux whilst being able to also retain a high level of accuracy / low uncertainty in measurement of the materials physical properties during and after that flux as it re-establishes equillibrium

    4) investigations into prospective experimental design to measure gravity waves

    I would very much appreciate references to any papers relevant, (no problem if they cost a bit, but price obviously must correspond to level of relevancy)

    Thankyou very much in advance for taking the time to share your wisdom knowledge & expertise.
     
    Last edited: Jun 26, 2014
  2. jcsd
  3. Jun 27, 2014 #2

    jedishrfu

    Staff: Mentor

    One thing to be aware of is that researchers also sometimes fudge or remove critical data points from their experiments to make them work out. When this happens, they have to pull their papers, suffer a great embarassment and possibly loss of job and criminal charges to say nothing of a destroyed career.

    My advice is to never never never go there.

    Scientifically its also bad science to have some hypothesis and then fit the data to prove it throwing away outliers without good reason. Those outliers may be the key to a new discovery even better than your hypothesis.

    With respect to gravity waves, are you referring to the phenomena of gravity waves in fluids or detection of General Relativity gravity waves? I'm thinking the latter.

    Here's a wiki article on the more common gravity waves in fluids:

    http://en.wikipedia.org/wiki/Gravity_waves

    and here's the GR gravitational wave:

    http://en.wikipedia.org/wiki/Gravitational_wave

    Halfway thru the article is a discussion on the methods of detection currently used.

    There are a lot of references there to follow up that can get you up to speed on this kind of research. One difficulty here would be the size of these detectors and the vast amount of money needed to construct them.

    So I guess you could investigate experimentally how you can get the same order of sensitivity from a much smaller piece of equipment. I think in the 60's Prof Weber constructed small device:

    http://en.wikipedia.org/wiki/Weber_bar

    which supposedly detected GR waves but was never duplicated by other scientists.

    Now we are building very large Laser interferometers like LIGO separated by large distances to detect very long wavelength GR waves or miniGRAIL and comparing coincidence detections between them.

    http://en.wikipedia.org/wiki/Ligo

    http://en.wikipedia.org/wiki/MiniGRAIL

    and for the future:

    http://en.wikipedia.org/wiki/LCGT
     
  4. Jun 27, 2014 #3
    Hi, firstly thankyou for taking the time to provide me with these links and your experience. In regard to the "fudging" of my results in my undergraduate years i do understand what you are saying, as i said im not proud of it and attribute it to a lack of maturity in my younger years accompanied by an arrogant attitude i developed that i was "above" experimentation and that all models i consider should be derived on a purely theoretical and non-empirical basis.

    But now that i am older i have began to see the significance of the experimental method, and the removal of any bias that has a tendency to diminish validity when one relies solely on his imagination and elementary application of logic.

    In regard to gravity wave measurement, i recall not far from where i live ( Western Australia) A team had plans to construct a laser array that was several miles long. The only problem i have with schematics that are of a large scale is the uncertainties magnitude increase that is accompanied by that larger scale design when one conducts statistical analysis of results, and especially seeing the aim here is to detect small-amplitude waveforms resulting from past extreme cosmological events, and this is the general form we see in the residuals experimental - theoretically predicted data for almost any physical quantity desired to be measured with high precision!

    So as basic as it sounds we come to the point where i dont honestly see the results of such a laser array method to be able to produce results where by we can definitively say it is in fact gravity waves that are being measured.

    Without referencing prior attempts i have been orientated around a basic (conceptual only, like i said, my practical skill set is still in its infancy) design centered on measurement of longtudinal wave forms observed in liquids which exhbit elasticity ( ie 'goo' ) but however the system must be isolated from seismic vibration which is the part im stuck at.
     
    Last edited: Jun 27, 2014
  5. Jun 28, 2014 #4

    jedishrfu

    Staff: Mentor

    What if it was a space-based detector?

    No seismic waves there but there still may be tidal side-effects.

    Its something to think about.
     
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