Research Journal

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

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.