Research Journal

March 10, 2006

I just created an "Other" page on the website. This will be the home of the quotations and physics-related ideas that will purely and concisely define my world view and future ambitions.

January 24, 2006

I've posted a summary of my SL research in the Fall 2005 semester on my home page.

Hopefully progress won't be impeded as much this semester, by the inconsistency in producing SBSL.

September 27, 2005

I just returned from my E=mc^2 Day event. Fred Goldhaber, Robert Crease, David Cassidy, and Massimo Pigliucci all gave wonderful and insightful talks.

Some interesting results with the SL experiment. I added 5 ml of glycerin to the water to make bubble trapping and stabilization easier to do. Indeed this was the case, except that producing SBSL was impossible! I even tried pumping on the water to remove any excess gas, but this did not help. It is very confusing since Ken Lee reported in his journal that 5 ml of glycerin significantly stabilized the SL bubble. I also replaced the glycerin doped water with fresh degassed water, but was still unable to produce SBSL, even at a driving voltage of 7 volts, which is quite excessive. This is frustrating since I have recently screwed down a CCTV camera into my lab table and connected it to a TV monitor which magnifies the image of the bubbles in the flask by a large but unknown factor. I want to use this camera to observe the SL bubble in greater detail. This means first getting SBSL again, which will simply require persistence and patience, and is guaranteed.

September 20, 2005

I'm back finally, to writing in my journal. The first few weeks of school have been a pain in my ass. Having my dorm room assignment screwed up for the semester and deciding what classes to take have made it difficult for me to continue with the experiments, until now. Anyway, the most recent experiments with SBSL have led to the following findings:

The degassing conditions necessary for SBSL to occur this time are strangely different. Degassing the water (that is, pumping it down by vacuum, until there are virtually no more observable air bubbles in the water, makes it impossible to sustain or even form a trapped air bubble. When a bubble is injected, it migrates towards the center of the flask, but then instantly dissolves. When air is partially dissolved back into the water (over the course of 6 hours of exposure to STP) the trapped bubble dissolves within several seconds instead. The following degassing procedure appears to be most effective in producing the necessary amount of gas content in the water:

1. Pump on the water in the flask until the pressure reading from the gauge meter is down to 20 Torr.

2. Once at 20 Torr, immediately close off the vacuum pump valve and test to seee if you can trap a stable bubble for a longer duration.

3. Repeat above procedure if initial pumping is not enough to form a stable bubble.

The next steps will be to try using water chilled to 10 Celsius, along with glycerin, and that Vitamin water I mentioned before.

August 18, 2005

On Friday of August 12th, we the students spent our last day together in the Laser Teaching Center. Of course we made sure it would be a memorable one. We first created a nice and mellow lab ambiance, with some of the lights turned off and and the optics displays turned on. We then created our own laser light show, where we took an old speaker and covered it with a latex glove to form a membrane which we epoxyed a mirror to. We then shone three lasers (the red HeNe, the green diode, and the violet) at the mirror, which reflected towards the ceiling. The idea was that when the speaker (which was also connected to an old radio that was connected to Dr. Noe's boom box), pulsates with each musical note, the laser beams would form random patterns that correspond to each note. The effect was quite fascinating and worked very well with the classical music we played such as Shostakovich Violin Concerto, Ave Maria, Vivaldi: Four Seasons, etc. People from the electronics center, the machine shop, and Dr. Metcalf's research group all came to see it. We then decided to enhance the show by pouring liquid nitrogen vapors around the mirror, so that one could see all the colorful laser beams converging and diverging. The oscillations of the looping laser patterns also reminded me of string theory since every note corresponded to a particular pattern of oscillations of a laser beam, in the same way that every mode of vibration of a string in string theory corresponds to a particular fundamental particle in the Standard Model. Indeed string theorists frequently use this analogy to describe what string theory says about our universe - it is a symphony of vibrating strings.

After the laser light show, Moon, Amol, and I went with Greg to his dorm to pick up his speakers which we used to watch "Death to Smoochy", while also eating pizza. The eggplant pizza was quite excellent-too bad we didn't try it earlier. Moon was the first to leave, even before the movie ended. Lindsey followed suit shortly thereafter. Matt and Amol then went to give their Simons talks. Nilus, Greg, and I stayed behind and cleaned the lab up a bit. I then went back to my dorm and finished packing my stuff to move out of my suite. Greg was gracious enough to help by using this cart he has to take my belongings downstairs and load them into my mother's car. I came back to the lab after packing and heard from Dr. Noe that a Simons student was using collapsing microbubbles to drive a small motor! Apparently John brought him back to the lab when I wasn't there and showed him my workbench and even trapped a bubble for him to see. Too bad I wasn't there to show him SBSL. Anyway, I spent the rest of the evening making up journal entries from August 7-11. Afterwards, I shut everything off at my workbench and left for home.

The fact that this was the last day at the LTC wasn't as depressing as I thought it would be, since all the other students, except for maybe Greg, will be returning throughout the year to continue on with their projects. Thus, I prefer to look at this last day not as the beginning of the end, but the end of the beginning. This was indeed a memorable summer. For me, I developed the skills and confidence to make things happen not just in my mind, but also with my hands, and further strengthened my interest in SBSL and the long term goal of working up to a replication of the sonofusion experiments. The other students in the lab here, created a research environment that I couldn't have been happier with. The chemistry we had as a group was important, I think, to each of our successes in our projects. I'm also going to miss all the intense discussions about physics, philosophy, politics, and religion. It's not everyday that you meet people who are comfortable enough with these subjects to discuss them casually. But this is what an intellectual environment is supposed to be - a haven for free-thought and freedom of inquiry. Finally, I sincerely hope that I contributed something concrete to the other students by my presence in the lab. This research experience would not have been what it is if I was singularly focused on Sonoluminescence, though I am happy to say that I achieved what I initially planned to do. I hope to see you all again soon; but in the mean time, good luck to everyone with everything that awaits you all this year, and thank you for helping to make this a productive, memorable summer experience.

~Maaneli Derakhshani

August 7-11, 2005

Much has happened since I last wrote. All the REU students are official gone, except for Greg and me. I finally managed to repair all the PZT transducers. The microphone wires and the red wire of one of the drivers were soldered in place and epoxyed back onto the flask. I then began driving the PZT's with the function generator and amplifier, while using the oscilloscope to register the signal picked up from the microphone. I could alway hear the signal when the PZT's were oscillating at frequencies below 20 kHz, and could always hear a fizzing noise when bubble were present in the flask from the undegassed, vapor distilled water. Indeed this is the type of water I initially used to try and trap a bubble. This was very difficult however. Every time I injected a bubble, it would get trapped far off from the center of the flask and would randomly oscillate; eventually the bubble would become so unstable that it would fly off to the walls of the flask. This would occur even if the acoustic field was at or close to the resonance of the flask. An indication of a successfully trapped bubble was ripples in the sine wave pattern on the oscilloscope. This was sometimes never observed, except when the bubbles were very well centered and stabilized. To see the bubbles, I had to use a high intensity light source (Fiber-Lite A3200) which was directed straight onto the flask, which was then placed inside a large black box that was made by the previous SL student, Ken Lee.
To find the resonance of the flask, I had to watch when the signal on the oscilloscope reached it's maximum amplitude, as I varied the frequency from the function generator. I often found this frequency to be between 25-27 kHz. I also had to reposition the ferrite rod in the inductor to maximize the signal amplitude. It should also be noted that I always followed these procedure after first sucking some water from the flask, as this slight perturbation in water volume would easily alter the resonance. I also noticed some other interesting effects of the undegassed water. When I would inject bubbles, they would all migrate towards an anti-node of the acoustic field near the center of the flask and combine to form a larger bubble. If I then violently injected a large concentration of air bubbles, there would be a small one forming near the center of the flask; and sometimes the bubble would rapidly orbit some axis and form a tail. This tail looks very similar to a cavitation vortex, which has been observed in the work of cavitation researcher Roger Stringham. I also discovered that for a sufficiently stable bubble, I could manipulate its position in one axis, by varying the frequency in steps of 10 kHz. This is probably due to some shift in resonance of the acoustic field in the flask. Indeed it is somewhat similar to the idea of optical tweezers, except instead of using light with orbital angular momentum to rotate a microscopic particle, I am using an acoustic field to change the position of the bubble along a particular axis. I suspect I could create an acoustical tweezer very easily then.

After becoming comfortable with bubble trapping, I then proceeded to degass fresh vapor distilled water. To do this, I used the vacuum pump to lower the pressure to 5 Torr and waited for the all the visible bubbles to leave the flask. This took approximately a half hour. After doing so, I then proceeded to trap bubbles in the degassed water. I found however that the bubble would not easily form immediately after degassing, implying that the water was too degassed. However, if I waited a couple hours, I could then trap very tiny bubbles, on the order of the thickness of a strand of hair. I also found in these conditions that by continuously injecting bubbles, they would migrate towards the initially trapped bubble, but they would not combine to form a larger bubble. I also found these bubbles to be far more stable, and very well centered in the flask. The bubbles would remain centered for a couple of minutes, versus a few seconds in the regular fresh water. To reach the conditions necessary for SBSL to occur, I also had to increase the voltage, just below the point before the bubble became unstable and flew away. This also took some practice but was eventually mastered. After understanding these nuiances of trapping bubbles in degassed water, I then proceeded to observe SBSL. On the first attempt, I cleaned the flask with denatured alchohol solvent, found the resonance of the flask, trapped a bubble, set the voltage just below the threshold of instability, shut off all the lights, including the high intensity light source and oscilloscope, and waited for my eyes to adapt to the darkness which took only a few seconds. Lo and behold, I was successful in seeing the bubble sonoluminesce (picture taken by Nilus) and I was so pleased that I cheered at the top of my lungs. Seeing the bubble was a bit difficult however. I had to look slightly off to the side of the flask, like you would in looking at a faint star in the night sky. Only then could I clearly see the dim, luminescing bubble. Indeed this is why it looks like a star in a jar. This was officially achieved with a frequency of 26,586.112 Hz and voltage amplitude of 5.7 volts, at 11:18 pm on Wednesday August 10, 2005.

It should be noted that I worked for several hours into the night trying to trap and stabilize bubbles. You would normally think that failing dozens of times would be frustrating; but surprisingly, I wasn't even phased in the slightest bit. I just kept plugging away like any good, patient scientist and was eventually successful. I have become so immersed in my project that every time I close my eyes, I immediately see vivid images of bubbles being trapped at the center of a flask. It's a bit bizarre, but also an indication of mastery of my domain. And this is of course the goal of every scientist.

At one point I wanted to first and produce MBSL (Multi Bubble Sonoluminescence), but Amol called Moon's cell phone and said he wanted to speak to me. He told me that he wanted me to get SBSL and send him a picture. It was this extra push that drove me to stay on track. After producing SBSL, I took an hour long break and then returned to producing SBSL. I managed to do it 6 or 7 more times, after which I was pleased enough to call it a day (at 2 am). Since Wednesday night, I have been able to continuously produce SBSL and have shown almost everyone in the lab. What was surprising however, is that the following day, I was still able to produce SBSL in the same water that was sitting in the flask over night. You would think that over 10 hours, enough bubbles would dissolve back into the water to make bubble trapping very difficult; but apparently this was not the case. At one point, when showing John, I managed to keep the bubble stable for over 5 minutes!! This was at a frequency of 26.588 kHz at 4.38 volts. I did also try MBSL by matching the resonant frequency of the flask and cranking the voltage amplitude to a maximum of 25.5 volts. By slightly varying the frequency, I could then hear a subharmonic pitch which sounded like a high frequency screetching noise (I can now produce this subharmonic effect at will). I'm not sure if this worked, because the light that I thought I was seeing could have been imagined. Later on, I chilled the flask with water down to 10 degrees Celsus in John's refrigerator and tried producing SBSL, but this was difficult because I did not have an oscilloscope to work with - other students needed it for their projects. Of course, I will try doing this again, and would also like to try using glycerin and Vitamin water. The Vitamin water, which is lemon flavored, is vapor distilled and contains magnesium based electrolytes. I would imagine a very strong SBSL effect if I were to chill the vitamin water down to 10 Celsius and add some glycerin. So this is something to try in the near future....(more to come).

August 5, 2005

The past four days has been a race to collect data and complete the powerpoint presentation. Both were successful, except that I wasn't able to observe the sonoluminescence since a PZT wire broke off and so did the microphone. Moreover, the wires connecting to the coaxial cable of the inductor and the op amp were crapped out. Thus, they had to be replaced. It was for all these reasons that when I tried driving the PZT's with the function generator, they did not respond. As of right now, the microphone is still detached, but the PZT drivers are repaired, thanks to my masterful soldering skills.

Last night, I spent the whole day creating my powerpoint presentation and rehearsing on my own. So I didn't leave the lab until around 1:30 am. The presentation seemed to have went OK, except for the beginning when I couldn't open my powerpoint on the provided computer. I had to use another REU student's computer to open it and doing all this consumed quite a bit of time. All the subsequent presentations looked very good as well. It is still not entirely certain if I will be able to stay for an extra week, but the hope is that I can. I really want to get to the SBSL.

August 1, 2005

Over the weekend I continued plotting points from the vacuum pump experiment with degassed water. I found that, initially, the rate of pressure rise appeared linear. However, after 2500 minutes, the rise started to level off very slightly. These plots (in red) were also made on the same graph as that of the initial vacuum pump measurements (in blue), where there was no attempt to degass the water. This plot can be seen here. Unfortunately, because these vacuum pump measurements take so long, I did not wait to see if the pressure in the flask would definitely reach equilibrium below atmospheric pressure. I ended the measurements at 202 Torr. The reason this number is so random is because the ZP pressure was scaled at 4 Torr, so I had to subtract 4 Torr from every direct reading from the pressure gauge. Nevertheless, because the pressure rise takes so long, I would conclude that equilibrium pressure is probably very close to atmospheric pressure and that continuously depressurizing the water after it stops bubbling, makes a small difference in the gas content of the water.

I also created 3 powerpoint slides for my presentation and finished writing my REU abstract which can be found here. And today, Dr. Noe and I cleaned my work station and organized the pump, meter, flask, amplifier, etc., in a more functionally efficient way (pictures coming soon). With Dr. Noe's help, I also wired the 36 volt power supply to the amplifier. I connected six outlets on the power supply to three wires from the amplifier, in such a way that there are four potential differences for the op amp. The op amp needs some sort of absolute reference frames, to know what input it is getting. We are now in the process of regluing the PZT's and trapping an air bubble to produce SBSL.

I also want to mention a phone discussion I had with a physicist at Boston University, Dr. Daniel C. Cole, whom I worked with in high school. I had several thoughts and ideas I wanted to consult him on and he was gracious enough to give me an hour of his time to do so. I told him of my research here on sonoluminescence and about some of the other optics projects we have going on. He was quite impressed by it all. We then discussed an experiment I recently designed to test the classical electromagnetic zero-point radiation model of Stochastic Electrodynamics (SED) versus the virtual electron-positron pair model of Quantum Electrodynamics. The idea is this: In the Casimir effect, cavity resonance occurs, like in light amplification in an optical cavity, when integer multiples of one wavelength can fit between two conductive, reflective boundaries. The constructive interference of the waves increases the vacuum energy density between the boundaries and produces a repulsive force between them. Now if one were to oscillate the two boundaries at the same fundamental frequency as the standing wave between the boundaries, that would clearly increase the energy and intensity of the E-field betwen them. If these boundaries oscillate fast enough, on the order of 1017 Hz, then what should emerge from the cavity is real, as opposed to virtual, photons. This could only occur if the energy given to the virtual photons in the cavity is larger than the energy needed to obey the uncertainity principle where dE*dT < hbar. But if the boundaries could amplify the E-field of the standing wave so its energy is greater than or equal to twice the rest mass of the electron, then would we not observe electron-positron pair creation between the boundaries? And what predictions would SED make for this energy range? Would it just predict photon emissions of arbitrarily larger energies? Cole answered in the affirmative and pointed out that SED cannot yet handle particle-pair creation. Moreover, the definition of a photon in SED is still somewhat vague (as it also is in standard quantum mechanics). Nevertheless, he agreed this would be an interesting experiment to do and still holds out hope that SED will be able to eventually deal with these fundamental issues. We also discussed sonoluminescence. I described how SL can be used as an acoustic black hole analogue model and that Casimir effect mechanisms have been proposed for SL (see my websites).

I then asked him about the interpretations of continuity and quantization of energy and spacetime. More specifically, I raised the point that in Einstein's field equation, the curvature and mass-energy tensors are correlated mathematically, but standard general relativity (GR) does not exactly explain how matter and spacetime are causally related, nor does it say whether or not spacetime is some sort of geometric background entity, with an existence independent of matter, or if spacetime is constituted by something more fundamental, like fields. In fact, general relativity assumes spacetime to be a classical vacuum, which is blatantly false according to Quantum Field Theory. Quantum fields isotropically pervade space via the Heisenberg uncertainty principle. However, if one assumes energy quantization, meaning photons, then there is only a finite volume of spacetime that can be occupied by such photons. This leaves momentary spatial "gaps" in between these quantum fluctuations, where the there is briefly some region of empty spacetime. However, the moment you posit the existence of a spacetime vacuum, the question then becomes this: what sort of physical properties does this spacetime vacuum have, independent of the quantum fluctuations? Standard GR says it is just a classical vacuum with no other definable physical properties, other than being able to "interact" somehow with matter and energy. But if it is a classical vacuum with no other definable physical properties, then how can something (matter) curve this nothingness called "empty space", rather than just perturb the quantum fluctuation field of quantum field theory? If on the other hand one assumes a continuous, electromagetic zero-point radiation field, then one could plausibly argue that spacetime is not some geometric entity indepenent of matter; rather, spacetime is the zero-point field fluctuations and what we observe as spacetime curvature is actually perturbations of the zero-point field fluctuations. This idea of mine is similar to the ideas of what physicist Andrei Sakharov proposed in 1967, that gravity may be an emergent effect of one-loop quantum field effects on a dynamically curving pseudoriemannian manifold. The difference of course is that he doesn't explain what causes space to curve. Nevertheless, the idea is very similar and does not require the fundamental assumption of spacetime quantization which is so dominant among most theories of quantum gravity. Of course, such an approach should still explain how matter is quantized and how energy is quantized in its interaction with matter. Standard GR, in my opinion, does a wonderful job of providing an elegant geometrical description of gravity in terms of "spacetime curvature", but it lacks a rigorous, causal, mechanistic explanation as to what this precisely means. Cole essentially agreed with my opinions, which was somewhat encouraging.

We then discussed hidden variable theories in quantum mechanics, and Cole sent me a paper by the physicist Ballentine, who argues that a stochastic or statistical interpetation of the foundational axioms of quantum mechanics is much more physically and logically coherent. I then quickly described a method I designed, to extract useful work from the lateral Casimir effect. I can't go into details about this contraption yet, since it may turn out to be practical and workable, and so I wouldn't want my idea to be "ripped off"! He also found this idea interesting and suggested that we discuss it another time. So the past few days have been quite productive and intellectually stimulating to say the least!

Also, I want to mention that I was fortunate enough to have a string theorist participating in the Geometry of String's Vacua, move into my suite. It'll be interesting to see what sort of discussions come out of this situation.

July 27, 2005

This morning I went to the String theory lecture, entitled "Type IIA Flux Compactification". I managed to understand some of the talk, which was encouraging. It was also exciting to see the exchanges between all the physicists during the Q&A session. Later on in the day, I discussed acoustical vortices with Marty and contemplated the use of optical vortices in a BEC (Bose-Einstein Condensate) to produce optical black holes. I also read an interesting paper which reported on the work of two astrophysicists who have recently suggested that what we think are black holes do not exist and are really just gravastars, which are highly condensed spherical shells of matter in a BEC state, with a negative gravitational pressure pushing outward. Apparently gravastars resolve a number of problems that exist with a singularity picture of a collapsing neutron star. They may also provide a potential explanation for the cosmological constant, since the negative pressure inside a gravastar is equivalent to the cosmological constant value. So essentially, the universe and all the matter inside it would be like a giant gravastar.

I also plotted the measurements of the rate of pressure rise in the flask, after being pumped. I found a linear curve up to 100 Torr, which was most unexpected. Perhaps the equilibrium state is much higher and so the leveling off is still unobservable. Hal suspects that there is a leak, since the pressure should have reached equilibrium at 17 Torr. He suggested that I use vacuum grease and a stopcock to seal the flask. However, when I pumped the flask with just air, the pressure stayed constant, indicating no leak. Moreover, Dr. Noe mentioned that 17 Torr is the vapor pressure of water and does not take into account the air pressure in the flask. This point is still not entirely clear to me, but in the mean time, I will degass the water in the flask and take measurements to compare to this one that I just completed.

July 26, 2005

Much was done today. I pumped the flask, empty, down to zero-point (ZP) pressure (5 Torr) to verify that there was no leak. Indeed there was none. I then pumped the flask with fresh distilled water down to ZP pressure and since then have been recording the increments at which the pressure in the flask increases by 5 Torr, with respect to time. I have found so far that it is taking exponentially longer for this to happen and that these results are very different from the previous run when the pressure increased at a much faster rate and continued to rise, suggesting that there was a leak. Thus, I conclude that this flask is completely vacuum sealed and more accurately shows how pressure increases in the flask.

I also went to the Strings workshop to speak to Rocek about the connections between General Relativity and sonoluminescence, but he was too busy to speak. He did however ask me if I had made any progress on the idea of using PZT's, slightly out of phase, to induce a torque on the bubble. I told him that I had not. However, when I returned to the lab, I went over to Greg's work station where we discussed optical vortices. An idea then hit me. Shouldn't it also be possible to produce acoustic vortices? One possible way to do this I thought was Rocek's suggestions of creating sound waves, slightly out of phase to produce a Topological charge. These acoustic waves could potentially be used to transfer angular momentum to a sonoluminescing bubble, which would be very interesting to study for the simulation of black holes. Later that night, through Google Scholar, I found two papers on acoustic vortices; and it turns out they are produced by a one-sided hexagonal arrangement of PZT transducers, out of phase with each other! This could very well be an interesting project in it's own right.

July 25, 2005

Not too much happened today. Nilus gave a presentation on his optical lever project and we helped him construct the first paragraph of is upcoming report. In the morning, I went to the Geometry of Strings Simons Workshop in the ITP. Today was the first day of the event and it was quite informal. Martin Rocek, and Cumrum Vafa of Harvard, gave a short introduction about the workshop and how it would comprise of only one lecture a day, with the rest of each day being devoted to informal discussions about ANY interesting physics problems, not just string theory. I was very surprised to hear that the event would be this laid back. But I think this will be an invaluable opportunity to interact with the world's top mathematical and theoretical physicists. And that's no exaggeration. Some of the other participants are Ed Witten, Juan Maldacena, and Brian Greene. You can't get much better than that.

In the evening, I read about air solubility in water and found two wepages, one with a formula for Henry's Law for air solubility at STP. The other had an equation allowing you to compute the change in oxygen solubility as a function of temperature. I was unable however to find a general formula to express how air solubility as a function of pressure and temperature. Though it is absolutely certain that temperature decreases air solubility in water. I also did some calculations of the air solubility at ZP pressure, using these formulas.

July 22, 2005

Immediately this morning, Matt, Dr. Noe, and I proceeded to further simplify the expression Matt and I derived yesterday. We found that I(Load)=(V1/R1)*(R3/R5). At 11 am, Hal gave a talk, ironically, on the Op Amp circuit and the concept of feedback systems; and later on, about laser diodes. Unfortunately, Greg and I could not stay for the second half of the talk as we had to attend our REU lecture given by Prof. Michael Rijssenbeek. His talk was all about the Standard Model of particle physics. He was quite comprehensive, starting from the beginning of quantum mechanics, all the way to discussions of the Higgs field and Quantum Gravity. I enjoyed it very much. I asked a number of questions such as how can the graviton model be consistent with general relativity? At what energies do particle physicists expect to find the superpartners? And how can the Higg's boson itself acquire mass if it is supposed to be a mass giving particle?

Later on, Marty and I discussed the problems with PZT transducer adhesives and the vacuum pump. I came to the conclusion that I should probably try using electricians wax and/or simply reglue the PZT with epoxy.

July 21, 2005

Most of today was spent working on the Op Amp circuit. Matt and I gave a presentation on the Op Amp, but realized during the talk that our answers to the questions Dr. Noe was posing were rather incorrect. After about 2 hours of questions and discussion, I finally developed a deeper understanding of how the Op Amp actually works. Following the talk, Matt and I proceeded to rederive the equation relating output current to input voltage in the circuit (we got I(Load)=(V5/R5)-(V1/R1)).

Other than the talk, I did a complete derivation of energy quanta by applyingg the First and Second Laws of Thermodynamics for monochromatic radiation of low density. Unfortunately, the derivation had to be erased.

July  20, 2005

I spent most of my time today trying to produce a mixture of epoxy resin and hardener with a texture similar to that of the adhesive that came off the PZT. This did not seem to work unfortunately. Perhaps it would be best to just simply epoxy on the PZT and see what happens. We also had the LTC and Metcalf research group picture taken. It seemed to have come out well.

July 19, 2005

Today I got working on the resonance circuit. John told Matt and I to think about the OpAmp circuit and to try and understand how it works. This took a while, but we eventually derived a formula for the usable current or the constant current produced by a circuit with four resistors and an audio amplifier recieving a signal from a function generator. A problem later arose when the PZT transducer came off the flask, after it was removed from the water bath from the previous night. And apparently we could not figure out what adhesive was used for the PZT. It may have been epoxy, but it had a rubbery texture and dissolved from being immersed in water.

Other than this, Hal gave a lecture on the history of time and methods of measuring it. He also discussed how time is one of the most precisely measured quantities and how a second is defined to be 9,192,631,770 vibrations of a Cesium atom. We also went into some discussion about quantum mechanics. I asked Hal whether the transition of an electron from one state to another is instantaneous orhas duration. Hal said there are experiments suggesting both possibilities. This was not exactly clear to me. If it is the case that the transition is instantaneous, this would be a violation of causality since there would be no time needed to go from one state to another. Thus I am willing to bet that the transition has duration and can probably be better explained by quantum electrodynamics. We also had some discussions of measurement theory. Hal remarked that we can't meaningfully talk about the electron existing in a definite, until it is observed. The electron is in a superposition of states. This Copenhagen interpretation is common among experimentalists. Aside from this lecture, I continued studing the OpAmp circuit diagram.

July 18, 2005

Dr. Noe returned today. He first talked about his vacation and the places he went. We then went to the pizza lunch in the seminar room where we discussed the progress made on our projects with Hal. During this lunch, I read an excerpt to Hal from the Optics text by Hecht, where Richard Feynman explained why light is made of particles called photons, not waves. I then asked him what his thoughts were. He replied, "Everybody makes mistakes," referring to Feynman. He still maintained that light behaves as waves. I have to read more about how QED explains interference and diffraction in terms of photons, but I think there are problems with both models.

Other than this, I read the pressure on the gauge meter and found it to be at 280 Torr. I then decided to do a test to see if pressure increase when uniformly heating the flask. This was suggested by John. Of course the pressure will increase sincean increase in temperature reduces the solubility of air into water, and also gives the air molecules more kinetic energy, thus increase the pressure inside the flask. To do this experiment, I first filled a plastic container with deionized water and measured its ambient temperature which was 21.1 Celsius. I then heated the water-filled container in a microwave for 2 minutes to a temperature of 37.8 Celsius. The flask was then immersed in the heated water and the pressure gauge was carefully observed. In 5 minutes, a pressure increase of 5 Torr was observed, from 280 Torr to 285 Torr. after which, the pressure rise in the flask regressed back to the preheated state. It seems plausible that there is a leak in the vacuum pump, considering that the pressure inside the flask doesn't seem to be reaching any equilibrium below room temperature so far. This experiment ended at around 11:30 pm.

Moon was also in the lab at this time, learning how to use Mathematica. She then assisted me by using Mathematica to calculate the Planck energy density, and the quantum mechanical zero-point energy density. The purpose of doing this was to check if my approximate order of magnitude calculations of these values were correct, and if the ZPE density is greater than the Planck density. The significance of both these values is that the Planck energy density is the critical mass-energy density needed to form a quantum singularity or black hole, and the ZPE density is the theoretically predicted energy of the vacuum of space, interpreted as fleeting virtual electron-positron pairs. If it turned out that the energy density of the ZPE was greater, this could then allow one to interpret the ZPE as being comprised of virtual quantum singularities. Unfortunately, the calculations showed the Planck density to be three orders of magnitude greater than that of the ZPE.

July 15, 2005

Today I pumped the flask with water down to the 5 torr zero-point pressure. I then closed the valve and monitored the rise in vapor pressure inside the flask. This took a few hours. In fact, the rate of pressure increase, exponentially decreases; so it is very difficult to observe the equilibrium pressure since the pressure may still be changing. For this reason, I used a magnifying glass to carefully watch the needle as it moves. This first run was necessary test to scale the graph that I will now use to accurately plot the pressure change with respect to time. I also noticed that this test seems to require that the vacuum pump be continually filled with liquid nitrogen every half hour or so. Aside from the vacuum pump measurements, I taught Lindsey and Matt a little bitof special and general relativity. This discussion then led to another about time travel. I first explained how time may not be a fundamental quantity, but a relational property of one harmonic motion spanning another, as argued by Aristotle and physicist Julian Barbour. We then delved into other random discussions about metaphysics and naturalism, where Matt and I were defending a physicalist view of the universe and Lindsey was arguing for a more transcendental interpretation. Nilus was also involved, but he asked questions rather than taking a position. All in all, I'd say this was a productive day. On another note, I want to point out Moon's "other" page which has a very nice collection of quotes and poems. In particular, I found If by Rudyard Kipling to be very insightful. I disagreed however with the Einstein quote which said "No amount of experimentation can ever prove me right; a single experiment can prove me wrong." Theories can never be falsified for the same reason they can never be proven; they are only supported by inductive evidence i.e. experiments. It's surprising how the Popperian concept of falsification still survives among scientists. I also found it amusing that Nilus, Lindsey, and Matt were able to immediately recognized the fallacy in Einstein's reasoning.

July 14, 2005

This morning I filled the Pyrex flask with deionized water and reconnected it to the vacuum pump, in preparation for the measurements and tests I will run tomorrow. Additionally, I read some of the Hect Optics textbook and found it to be quite nice. The author seems to provide a very comprehensive treatements of classical and quantum waves mechanics, as well as optics. I found some extra sections on scattering phenomena and its connection to quantum theory. Indeed Hect confirmed my suspicion that the phenomenon of scattering is much more complex and poorly understood, which is why Amol and I did not have much success in trying to fully understand it. I also found the discussions on Quantum Field Theory and Complementarity to be very nicely treated.  Hect adresses not just the physics and mathematics but also the metaphysics of waves, which is important, I think, in fully appreciating the complexity of such phenomena.

July 13, 2005

We the LTC students and a group of graduate students, had our first official pizza lunch.  A talk was given by Jan, a German graduate student studying X-Ray Spectroscopy. Afterwords, John left for the week, while Marty stayed behind and looked at some of our projects.

July 12, 2005

This morning Greg and I had our REU field trip to Brookhaven National Lab. The tour was delayed because the bus would not start, so all the students just hung out in front of the SAC. At BNL we saw the Synchrotron Light Source and all the experiments it is being used for. We then had lunch in the BNL cafeteria where I happened to run into Bob Crease, the BNL historian. Afterwords, we toured the RHIC (Relativistic Heavy Ion Collider) which was fantastic. We then saw the STAR detector, as it was being disassembled. It's interesting to think about how such devices are so complex that no one individual physicist or engineer entirely knows how they work. After returning, I went back to the lab and brought the two audio amplifiers over to my work station.

July 11, 2005

Today I developed a simple MBSL experiment, after reading a paper by Lawrence Crum on the use of an ultrasonic horn to produce cavitation. I figure that if I were to superheat a flask of degassed water and then bombard it with ultrahigh frequency soundwaves from a high frequency generator, I should easily observe SL and with greater intensity than with normal degassed water.

Other than this, I checked the pressure in the gauge which was pumped on Friday of last week. On Friday, the pressure was 5 torr at minimum.  I concluded that this should be treated as the minimum or zero pressure point, since it will not go any lower. Now I will pump the flask with water and start taking readings of pressure increase. I also need to start tinkering with the audio amplifier. Time is of the essence.

July 7, 2005

Early in the morning, we all went to the seminar room for the third of Hal's lectures. This time, his talk was about the property of waves. We all did a demo where we stood side by side and moved our fists up and down, following each person to our right. This demo then led into a philosophical discussion about what a wave is, since it was difficult to state whether we created a wave in our demo. I suggested that it is not a wave since a wave carries energy and momentum plus information. The latter concept is difficult to define, but I argued that it was related to causality. Basically, for information to be communicated, there must be a causal connection throughout a wave. And this causal connection arises out of a transfer of energy. But since no energy was transmitted, it did not fit the definition or properties of a wave, so I argued that the "wave" in our demo was an illusory perception. Metcalf challenged my implicit assumption that all physical processes are causal by bringing up quantum mechanics and radioactive decay. Nevertheless, I am still convinced that the concept of a wave is clearly definable. We then went on to quantitatively define waves using the sine function in the z direction. Afterwords, when John and Hal left, Greg gave a mini-talk on modern physics to Lindsey and Moon, after being asked about what photons are. He discussed the photoelectric effect and quantization of energy; I then said a bit about GUT's (Grand Unification Theories). Moon seemed particularly interested in these ideas.

In the afternoon, I tried pumping the SL flask to take measurements of pressure change, but found that there was a leak somewhere. John then came over and tried to find the leak, but somehow ended up sucking water into the pressure gauge. Thus, I had to take the gauge apart, clean it, and reassemble it. We then found the source of the leak which was a torn valve. After replacing the valve, we then discovered that the rubber stopper was also leaking air; so I ran the vacuum pump without the flask and was able to lower the pressure to as little as 4 torr. I then left the gauge meter at that pressure over night.

July 6, 2005

In the morning, John talked to us about the lab's DOS computer and its spreadsheet program.

At around noon, Greg and I went to the second REU lecture titled, "Imaging the Surfaces of Rotating Stars". The speaker, Dean Peterson, is an astrophysicist and was showing us how rotating stars can bulge out at their equator and also produce jets at their poles, with temperatures hotter than the surface of the star. He also talked a fair bit aboutinterferometry and diffraction. His discussion about the star properties was very interesting because it reminded me of my theories about how angular momentum would affect the behavior of a SL bubble. Indeed at the Q&A session, I had an exchange with him on whether or not these data of rotating stars could be used to help predict how a SL bubble would be affected by spin. He acknowledged the similarities in SL and the differences, noting that stars are stabilized by their own gravitational and magnetic fields. Nevertheless, he suggested experimenting with the idea.

July 5, 2005

Today was the second of Hal's lectures. This time it was about noncommutable operations such as matrix transformations. It reminded me of my linear algebra class, but was not at all hellish. Indeed it was nice to see the application of matrices in describing the effects of polarizers. Following Hal's lecture, we attempted to find a general polarizer matrix by which we could multiply an electric field vector and achieve the resultant electric field vector after polarization. A contrived solution was found by Amol, but the actual one was discovered by John and Lindsey and can be seen on either Amol or Matt's journal webpages. I continued tinkering with with the vacuum pump, trying to decide how to scale the measurements of pressure increase, since it takes much longer than I anticipated.
In the evening, Nilus, Moon and I did an experiment to determine the pitch of a screw behind a mirror mount indirectly via an optical lever setup.

I have been contemplating methods to enhance sonoluminescence, using microwave radiation. Over the weekend, I was playing around with superheated water, which is water heated past its boiling point without boiling. The potential energy tensioned in the water molecules, make the liquid very unstable; and the slightest perturbance will cause bubbles to nucleate and to release large amounts of thermal energy. My idea is to first tension a liquid with negative acoustic pressure in the same way that Taleyarkhan did with his sonofusion experiment. A small volume of liquid in the node of the acoustic field would then be irradiated with a focused beam of low energy microwaves, thus nucleating a cluster of small bubbles. These bubbles will then expand in volume because of the negative pressure field, and the subsequent collapse of the bubbles will occur with much more force. The advantage, I think, with my approach is that for any sonofusion experiment, the use of microwave radiation, rather than neutron radiation, will make any subsequent measurements of neutrons or thermal energy, much more reliable since there is no spurious neutron source. It's also easier to do, though probably a bit dangerous.

June 30, 2005

This morning, Hal Metcalf took us all over to his conference room and gave us a two hour lecture on the logic and philosophy of complex numbers, as well as his own philosophies about teaching. On one particular question, he asked me to prove that (8)(1/3) = -1 + isqrt(3)/2. Unfortunately, it did not work out; not because I made any error in my algebra, but rather, because the statement is wrong, as Greg and I later realized. It's the division by two that's incorrect.  This became a "homework" problem after it did not work out. Hal also kept on emphasizing how i is not a number; but this is dependent on the definition of a number. So I asked him what his definition of a number is, but there was no clear answer. For this reason, my question of "what is a number?" also became a homework problem. Considering his comments about the "magic" of complex numbers, I asked him if he thought mathematics is invented or discovered. His answer was not very surprising. He is a mathematical realist, meaning he believes that mathematics is tautology and so exists independent of our minds. He then went on to talk to us about how polarizers work. Afterwords, John discussed Euler's Formula of eix=cosx+isinx and how it can be used to derive most trig identities. Moon then found a very elegant derivation of the Euler formula using integration.                                

In the afternoon, we discussed a variety of topics including the dispersion relation, group and phase velocity, reflection, and the feasibility of making a light-saber. I should point out that all these discussions were initiated by Amol. One thing that also continues to bother me about reflection is how reflected light can have the same intensity, if only a fraction of the light that is isotropically scattered, is constructively interfering. I also don't understand how information is defined and how it is stored in the signal velocity rather than the phase velocity. In the evening, I took some time to read another paper on sonoluminescence from the red binder.

June 29, 2005

I spent the morning reading two long papers on SL and sonochemistry. Later on, an acquaintance of John Noe, who is a physicist working with Tom Weinacht, came to say hello. Afterwords, John further discussed the small angle approximation, as well as variations of multiple-slit diffraction. Greg and I then went to the REU tour of the Nuclear Structure Laboratory (NSL). There, we met and spoke to the two other Stony Brook REU students. I've seem the NSL twice before, but it was nevertheless nice seeing it again.

Amol asked two more interesting questions today. The first was about why certain objects are black in color. The other was how reflection of light in one direction is possible if the atoms comprising a surface scatter light waves in all directions. Since me, Greg, and John couldn't adequately answer his questions, we had to recruit the expertise of Hal Metcalf, who was able to answer the questions much more adequately; although the problem of why light doesn't scatter laterally or backwards in a dense gas medium, still remains a mystery.

Afterwords, John assembled the vacuum pump and showed me how to handle the liquid nitrogen that was needed to make it work. This was pretty fun, as I later got to mess around with large quantities of it. Greg and I then degassed the flask filled with water. This was the first day of doing something hands-on with the SL equipment and I look forward to more of it. 

June 28, 2005

Today, Dr. Noe did a review of calculus and discussed Rayleigh's criterion. At lunch, we had some discussions about random physics topics like which father-son combo won the Nobel prize. Afterwards, Dr. Noe gave us a long spring which we created longitudinal and standing waves on. Greg discovered an interesting phenomenon where a longitudinal wave turns into a transverse wave after a certain time and back to a longitudinal wave.

Amol also asked Greg and I a question about why in a dense gas medium, a propagating beam of light will only be scattered in the direction of motion and not laterally and backwards. We tried answering his question but am not sure if we were successful. For this reason, we will ask Dr. Noe tomorrow.

I then went to a meeting with Fred Goldhaber and Robert Crease, about the Quantum mechanics and philosophy course we are creating for spring of 2006, so I didn't get back to the lab until much later. However, I did manage to speak to Martin Rocek and Fred Goldhaber about my idea in treating a sonoluminescing bubble as a black hole analogue. They both said they were intrigued by the notion and found it to be plausible, though they admitted to not knowing enough about fluid mechanics and analogue models in GR to give much more feedback. Rocek did however brainstorm some ideas with me on how to rotate a bubble, using perpendicular pairs of transducers, and about what other liquid solutions might be interesting to test. So both Rocek and Goldhaber's reactions seem very encouraging and I will continue to communicate with Martin on these ideas. Ideally, I would like one of them to help me quantitatively analyze how a spinning, sonoluminescing bubble would behave.

June 27, 2005

The high school students started at the lab today. After meeting them, Greg showed them the basic bash commands. Dr. Noe then spoke to them about what would be required of them and what sort of thinking is necessary to be successful in their research. All the students seemed intensely interested and asked a number of insightful questions.

After returning from lunch, I showed the students my SL experiment to-be and suggested to Greg that he show them the Fresnel Spot that he produced. After doing so, Dr. Noe showed us a number of different optics phenomena such as variations of the Fresnel Spot, diffraction, interference, polarization, and a number of others.  I then continued reading papers from the red SL binder that Noe has here.

June 24, 2005

Not much happened today for us the students. After lunch at the Curry Club, Greg and I went to Dr. Metcalf's group discussion, where we heard about the research his team was conducting and the problems they were facing. The way they seem to deal with many technical problems appears to be plenty of brainstorming and improvisation, which was quite interesting.

Dr. Metcalf even asked me and Greg to give future talks about the research we are doing, which is something I certainly look forward to. At the lab, I brought over all the SL equipment such as the function generator and the vacuum pump, in preparation for next week when I actually begin doing hands on research.   

June 23, 2005

Today I spent most of my time reading more papers on SL and also learning the bash commands. I also continued to think about the possible extensions to the sonoluminescence experiment and about the plausibility of the alleged sonofusion effect. To this extent, I read a couple of sonochemistry papers by Ken Suslick while also reading about how viscosity and vapor pressure affect the sphericity and temperatures of cavitation.

I am contemplating methods involving the use of a pulsed YAG laser to induce a cavitation bubble and then driving its implosions with the acoustic field generated by PZT transducers. I have also thought about the use of various liquids and think that nonpolar organic liquids with high viscosity and low vapor pressure would be interesting to try. I also read parts of the first book of the Feynman lectures that Dr. Noe owns. Feynman's style is exactly what I like. Some good historical background mixed with precise, physical explanations of the concepts, all of which lead to elegant mathematical derivations.

June 22, 2005

    Last night I had a most interesting thought. The imploding behavior of SBSL appears very similar to that of a collapsing neutron star which will eventually form into a black hole. And when bubble implosions occur close to a solid boundary, the cavity collapse is very asymmetric and generates high speed jets of liquid that move through the bubble's interior and penetrates the opposite bubble walls like so

This form of cavitation looks very similar to a static black hole with the jets of liquid being the analog of the jets produced from a black hole and the cavitating center of the bubble being analogous to the event horizon. Of course the difference in the analogy is that the collapsing SL bubble is not stable and in the case of spherical collapse, will eventually re-expand. Nevertheless, I wondered if sonoluminescence could be treated as a general relativity analog model and if there is a way to produce these "black hole" like asymmetrical cavitation bubbles without using a solid boundary, while also prolonging the collapse time.  

    It turns out I was partially correct! General relativity theorists often talk about analog models of black holes in condensed matter physics. And after doing a google search on "sonoluminescence analog model", I found a lecture by GR theorist Matt Visser, from a conference on analog models in GR, about acoustic black holes! And it turns out he had a discussion about oscillating bubbles like in SBSL which form an acoustic apparent horizon, meaning that as the bubble collapses at supersonic speeds, the sounds waves are swept along with the flow and cannot escape from that region, just like light cannot escape from the event horizon of a black hole. But the reason the term apparent horizon is used is that, as I said, the bubble eventually stops collapsing and re-expands, so the acoustic horizon is only temporary. Of course, if someone could figure a way to prolong the collapse time or increase the speed of collapse, it is theoretically possible that one would observe the analog of Hawking radiation! So you wouldn't see real photons, but rather phonons, which are quasiparticles or quantized sound wave packets.

    Once again, perhaps giving a cavitating bubble a lot of angular momentum will induce this effect. If the imploding bubble has a supersonic angular velocity, then this will cause the equator of the spherical bubble to bulge out and expand, while the top and bottom ends collapse into each other and form the subsequent liquid jets. What would hopefully form is a continuous cavitating vortex of water, spinning at supersonic speeds. I don't know if these conditions would be sufficient to observe phonon radiation, but it may be worth a try. Water would seem like the first liquid to test, but probably organic liquids which have a high phase change coefficient would be better, as the bubbles would be much more stable and won't prematurely cavitate. So this is certainly an unconventional idea for a project with the phenomenon of SBSL, and one that I will keep in mind for the future.   

     In terms of what went on today, Fred Goldhaber gave the first REU seminar talk entitled "A new way of Introducing Quantum Mechanics - The Einstein Way". Prof. Goldhaber personally gave me this talk before, but nothing wrong with hearing it again. It centers around the idea that after Einstein published the 1905 paper on the Photoelectric effect, he should have been able to make the creative leap that though light behaves like a particle when it is absorbed and emitted, only a wave model, which was already experimentally confirmed, could accurately explain the behavior of light in the intermediary state. In other words, light does not follow definite trajectories as in Newtonian mechanics, but rather, has a position defined by a probability amplitude. So in other words, just from the observation of the photoelectric effect and the wave behavior of light, Einstein had should have been able to derive the schrodinger wave equation, as well as the Compton effect and the deBroglie wavelength. Indeed had he done so, it would have been 20 years earlier than when these discoveries were actually made. Though much of my education of quantum mechanics is self-taught, I very much like Goldhaber's approach, as he was able to axiometize the foundations of QM in a very elegant way. Indeed it then makes the formulation of QM seem much more logical.  Of course, I do think that Einstein contemplated this approach, but then backed off from it as soon as he saw where it was heading. Einstein was very much a local realist and wanted the preserve the ontological assumptions of causality and classical determinism; and this was why he disliked quantum mechanics so much, because quantum theory reshaped these assumptions in a very bizzare way that seemed very illogical from the point of view of his classical physics intution.

June 21, 2005

    For the past couple of weeks, I've been reading a number of different papers on SBSL (Single Bubble Sonoluminescence) and laser induced cavitation by Seth Putterman, Rusi Taleyharkan, Ken Suslick, and others. Some of these papers can be found on my links webpage. Without a doubt, I would like the end result of this REU project to be a replication of Ken Suslick's SBSL experiment in sulfuric acid . What could be more exciting for this project than to produce a cavitation bubble as bright as an incandescent bulb! Of course the even longer term goal of this project is to lead into a replication attempt and variation of the alleged "sonofusion" experiment conducted by the ORNL and RPI teams. But that will come even later in the future.

    Now as long as I can consistently produce SBSL in light water, with some slight variations like the addition of glycerin, then replicating Suslick's work is just a matter of acquiring an aqueous sulfuric acid solution. Chances are I can acquire this stuff from the Chemistry department; but I will worry more about that only when the time comes. I have also thought of using lasers to produce Mie scattering so as the measure the size of the SL bubble, and to observe its general effects on bubble cavitation. It might also be interesting to see how or if the SL bubble is affected by magnetic fields or by angular momentum. The reason to suspect the former is that recent studies of SL by Putterman and Suslick suggest that molecular dissociation of the cavitating fluid may be taking place and forming an opaque plasma. This implies that there are also charged particles and strong electric fields, which would be affected by magnetic fields. The latter consideration results from observations that bubbles can implode by flattening into nonsperhical, pancake shapes and produce water jets from both ends. So, it might be possible to increase the force of such a collapse by spinning the bubble. Another problem to think about is the apparent subharmonic pitch that was observed by Dr. Noe and his previous students. We've considered looking at how the "glass harmonica" works to possibly help us understand this subharmonic anomaly. For now though, the most important task is to produce conventional SBSL.

    The obstacles here appear to be first repairing the microphone transducer. Dr. Noe already deattached it by cutting through the layer of epoxy glue that was attaching it to the bottom of the spherical Pyrex flask. I'll have to solder the wires back on now and then reattach it. It would also be a good idea to clean out the flask with alcohol, since it looks quite dirty.     

The picture all the way to the left is the Pyrex flask where SL occurs. The latter three are of the microphone transducer.
    Aside from all this,  Dr. Noe spoke to Greg and I about the high school students and what else we need to do to get the ball rolling on our projects. Certainly one thing I must work on is familiarizing myself with all the Bash commands and becoming comfortable with creating new webpages through Linux. Otherwise, Dr. Noe asked us a deceptively simple question about how one would measure the "size", or really the diameter of a laser beam, with a fan and photodetector. After a couple ideas from both of us, Greg seemed to have figured out the way to do it and with the help of Dr. Noe, he derived an integral formula which models the intensity of a laser beam as a function of its radius. It's amazing how you can derive such an elegant mathematical model just from the initial thought of "how would you measure the size of a laser beam?" That's why physics is beautiful.