Recently in Chemistry Category

Eight weeks ago, I hosted Dr. Aubrey de Grey for his second talk at Google in Mountain View, California, a follow-up to his earlier Google talk in the SENS series, "WILT: taking cancer seriously enough to really cure it":

ABSTRACT

The intrinsic genetic instability of cancer cells makes age-related cancers harder to ... all » postpone or treat than any other aspect of aging. Any therapy that a cancer can resist by activating or inactivating specific genes is unlikely to succeed long-term, because pre-existing cancer cells with the necessary gene expression pattern will withstand the therapy and proliferate. WILT (Whole-body Interdiction of Lengthening of Telomeres) seeks to pre-empt this problem by deleting from as many of our cells as possible the genes needed for telomere elongation. Cancers lacking these genes can never reach a life-threatening stage by altering gene expression, only by acquiring new genes, which is far more unlikely. Continuously-renewing tissues can be maintained by periodic reseeding with telomere elongation-incompetent stem cells that have had their telomeres lengthened in vitro with exogenous telomerase. I will describe why WILT may become a uniquely comprehensive anti-cancer modality, and the practicalities of performing it and avoiding side-effects.

Some weeks back, my (now) friend Dr. Daniel Kraft, a physician scientist at Stanford, came to Google at my invitation to give a talk, "Everything You Wanted To Know About Stem Cells... But Were Afraid To Ask":

ABSTRACT

Stem cell technology and the debate surrounding it has generated a great deal of excitement ... all » and controversy in recent years. The field is surrounded by misconceptions, hype and yet very significant potential. In this talk we'll cover: defining what are stem cells really and where do they come from... the differences between embryonic stem cells and 'adult stem cells' (i.e. derived from our own bone marrow, fat, umbilical cord blood, placentas and even our kids teeth) and emerging technologies to utilize these cells in powerful and novel ways. We'll cover current clinical uses of stem cells, ongoing clinical trials in regenerative medicine (i.e. using marrow derived cells to treat heart attacks, vascular disease, stroke and even diabetes), upcoming trials utilizing embryonic stem cells, and some of the likely near term and future applications as well as challenges remaining in order for this field to reach its full potential.

Aubrey de Grey gave a Tech Talk at Google's Mountain View campus this week, and I was privileged to attend. I've seen him give a longer, earlier version of this presentation before - at Stanford in June 2005 - and was impressed more than ever. Enjoy:

ABSTRACT

It may seem premature to be discussing approaches to the effective elimination of human ... all » aging as a cause of death at a time when essentially no progress has yet been made in even postponing it. However, two aspects of human aging combine to undermine this assessment. The first is that aging is happening to us throughout our lives but only results in appreciable functional decline after four or more decades of life: this shows that we can postpone the functional decline caused by aging arbitrarily well without knowing how to prevent aging completely, but instead by increasingly thorough molecular and cellular repair. The second is that the typical rate of refinement of dramatic technological breakthroughs is rather reliable (so long as public enthusiasm for them is abundant) and is fast enough to change such technologies (be they in medicine, transport, or computing) almost beyond recognition within a natural human lifespan. In this talk I will explain, first, why (presuming adequate funding for the initial preclinical work) therapies that can add 30 healthy years to the remaining lifespan of healthy 55-year-olds may arrive within the next few decades, and, second, why those who benefit from those therapies will very probably continue to benefit from progressively improved therapies indefinitely and thus avoid debilitation or death from age-related causes at any age.

What a day! Just as I'm getting ready to attend Aubrey de Grey's talk at Google, I find out that a martial arts training buddy of mine, Dr. Pete Lohstroh, recently left his research position at UC Davis to take a senior scientist position at Telomolecular Nanotechnologies, specializing in the application of nanocircles to telomere extension therapy (one of several approaches they're taking). Congratulations Pete!

Nanoparticles Delivery of 'Suicide DNA' Kills Prostate Tumors

"...using nanoparticles developed by members of the Alliance for Nanotechnology in Cancer, a team of investigators at the Lankenau Institute for Medical Research, in Philadelphia, has developed a DNA-based therapeutic agent that has the potential to treat both enlarged prostates and localized prostate tumors. When tested in mice, this new agent specifically targeted prostate tissue, producing no toxic effects in surrounding tissues..."

Frank Bieser writes:
> Perry E. Metzger wrote:
>> Without enough people working on the problem, we won't finish in
>> time. Right now, I'd say smart people are the biggest missing resource.
>
> And why might that be? Where did all the smart people go?

They didn't "go" anywhere. They've never been in the field.

How many smart people were working on orbital rocketry in 1920? A half
dozen, perhaps. Lots of people claimed the whole idea was bunk, too,
including the New York Times. Later on, lots of people joined up.

Today, not many people are working on Drexler's vision. That doesn't
mean it isn't worthwhile -- it just means that the field is young and
lots of people are still skeptical about it. I suspect that the number
of people actively working on it numbers less than 20, and possibly
less than 10.

There is enough work for thousands of people to push on this for many
years to come. At some point, we'll get IA or AI and the pace will be
able to pick up, but that point still seems pretty distant. Meanwhile,
direct molecular manipulation and molecular manufacturing pose a very
hard set of problems -- possibly the hardest engineering problem yet
faced by mankind -- and we need more minds to make progress. On the
flip side, MNT will also bring the biggest revolution in civilization
yet experienced, dwarfing everything that came before, so I see it as
a worthwhile problem to attack.

Still, we lack enough smart people working on it. As any good VC can
tell you, money is something of a commodity, but smart people are
rare. More smart people are needed.

Perry

I'm going through a year's worth of iPhoto archives and found this, taken in organic chemistry lab by my friend Jenny... me in Maximum Nerd mode:

An interesting blog article about the use of dendrimers in targetted drug delivery systems, sent me by Tom Burroughes in London.

University of Michigan scientists have created the nanotechnology equivalent of a Trojan horse to smuggle a powerful chemotherapeutic drug inside tumor cells – increasing the drug's cancer-killing activity and reducing its toxic side effects.

Previous studies in cell cultures have suggested that attaching anticancer drugs to nanoparticles for targeted delivery to tumor cells could increase the therapeutic response. Now, U-M scientists have shown that this nanotechnology-based treatment is effective in living animals.

This type of news carries a special type of urgency for me, as I've recently been informed that my good friend Chris Tame, in London, has been diagnosed with epithelioid angiosarcoma of the bones (spine & hip so far.) His oncologists are working hard to find the primary source of the cancer. In the meantime, any new developments in the effectiveness of chemotherapy with short & medium term time horizons are of great personal interest to me and my friends.

I needed to look this up for study so, given how difficult it was to find this value, I'm mentioning it for future Googlers:

According to "Chemistry of Amines," in section 4, "Important Reagent Bases", the pKa of the N-H proton on the conjugate acid of lithium diisopropylamide (LDA) is 35.7.

Thanks to Perry for bringing this to my attention: "Rapid Gene Synthesizer Will Enable Custom Microbe Construction."

I am really, really enjoying my biology class, a concentrated term of cell & molecular biology. Students in this program spend about four times as much time in lab, learning industrially useful techniques, as do students in comparable programs in the University of California system. In the last three weeks, I've had hands-on time doing protein electrophoresis, conjugation (bacterial DNA transfer), and DNA electrophoresis. Here's an image of our team's first DNA gel:

The DNA is from purified coliphage Lambda virus, 48,502 Kb (kilobases) in length. Lane 1 is pure, uncut DNA. Lane 2 is DNA restricted (cut) by Eco RI enzyme, Lane 3 restricted by Hind III, and Lane 4 by both (the restriction sites are different, resulting in more, smaller DNA fragments.)

Lanes 5 through 7 are subsamples taken from 2 through 4, subjected slowly and thoroughly to the action of the enzyme DNA ligase, resulting in outrageously long, randomly recombinant strands.

The gel is purified agarose treated with ethidium bromide. The image above is a high-contrast Polaroid of the gel UV-transilluminated to fluoresce in the visible spectrum (reddish orange, here shown in black and white).

This stuff is outrageously fun.

In science, 'fact' can only mean 'confirmed to such a degree that it would be perverse to withhold provisional assent.' I suppose that apples might start to rise tomorrow, but the possibility does not merit equal time in physics classrooms.

Stephen Jay Gould

I seemed to have been the only person this morning other than my instructor to have paid attention to the warning on the bottle of crotyl chloride, "Danger: lacrymating agent!"

It was also amazing to see the number of people dispensing silver nitrate without gloves... low toxicity risk, but high chance of Rorschach tattoos on one's hands (hint: silver nitrate is photosensitive.)

Perry Metzger reports in "Immunotherapy Halts Alzheimer's in Mice" that:

...the injection of antibodies targeting the beta amyloid plaques into the brains of mice with a close analog of Alzheimer's disease managed to trigger a response in which the immune system cleared the plaques. Neurofibrillary tangles associated with the disease cleared spontaneously shortly after the amyloid plaques vanished.

Perry Metzger reports that Francis Crick has died. He will be missed.

My old friend Perry Metzger gave in today and finally started a blog. Now to convince him to add a comment mechanism...

Courtesy of Perry Metzger today: "New Technique for Imaging May Improve Study of Proteins" and its related story direct from IBM, "IBM Scientists Make Breakthrough in Nanoscale Imaging."

IBM scientists have achieved a breakthrough in nanoscale magnetic resonance imaging (MRI) by directly detecting the faint magnetic signal from a single electron buried inside a solid sample.

A biophysicist talks physics to the biologists and biology to the physicists, but when he meets another biophysicist, they just discuss women.

Unknown

A big thanks to James and Steph for their gift of the Springer title Name Reactions by Jie Jack Li, a compact atlas of 331 reactions in organic chemistry, from "Abnormal Claisen rearrangement" to "Zenin benzine rearrangement." This should be truly useful from the fall term onwards; thanks guys!

Recommended by Monica White: the blog "Bizarre Science."

Now, I am no climate scientist, but I harbor a suspicion that maybe, just maybe, one factor impacting on the Earth's climate just might be - now, I'm just throwing this out - the sun. I find discussion of the sun's impact on global weather to be oddly absent from the reams of paper speculating on how minute variations in various gases here on earth may affect climate, rather like speculating on how adjusting the air pressure in your tires a few ounces might affect fuel efficiency without ever considering the, well, fuel you are putting in the tank.

Robert Clayton Dean

This is nasty and upsetting news from Steve Pegram: "Rocket Hobbyists Dropping Hobby" due to hamfisted, jackbooted regulation by the goons of the BATF. Just when we're seeing the spirit of innovation in rocketry and space travel rekindled, the government is working to snuff that spirit. This crap needs to be fought... which seems to be happening by default, since many rocket hobbyists have chosen to ignore F-Troop anyway.

Organic chemistry is the chemistry of carbon compounds. Biochemistry is the study of carbon compounds that crawl.

Mike Adams

When the war finally came to an end, I was at a loss as to what to do... I took stock of my qualifications. A not-very-good degree, redeemed somewhat by my achievements at the Admiralty. A knowledge of certain restricted parts of magnetism and hydrodynamics, neither of them subjects for which I felt the least bit of enthusiasm. No published papers at all... Only gradually did I realize that this lack of qualification could be an advantage. By the time most scientists have reached age thirty they are trapped by their own expertise. They have invested so much effort in one particular field that it is often extremely difficult, at that time in their careers, to make a radical change. I, on the other hand, knew nothing, except for a basic training in somewhat old-fashioned physics and mathematics and an ability to turn my hand to new things... Since I essentially knew nothing, I had an almost completely free choice...

Francis Crick
What Mad Pursuit, Basic Books, New York, 1988, pp 15-16.

In chemistry lecture, and studying outside class, I often use a molecular modelling kit made by Darling Models to help me visualize the stereochemistry of various molecules. I like my kit, but it's rather bulky, so I don't always have it immediately at hand. A few days ago, one of my classmates showed me the kit she carried, which is very much more compact and does most of what we need to know (in respect of linear and branched hydrocarbons and some of their halogenated derivatives): a Student Organic Chemistry C-set from Hinomoto Plastics. The Hinomoto kit fits in a small pocket pouch, and is very solidly constructed. Some of the components look amusingly like dice from the game Dungeons & Dragons, by the way.

Here's an interesting short article by Ralph Merkle written when he was working for Zyvex (before he moved on to Georgia Tech): "Nanotechnology and Medicine".

[A bit of context: this quote refers to an amusing incident where a religious cultist in a forum I frequent blew up when he was called out on an issue of "quantum mysticism" he couldn't support. - Russell]

I think [a particular theist twit] actually did good job of defining by example an important concept in quantum mechanics: the uncertainty principle.

He obviously has some beliefs, and we could either know the position or the energy of his beliefs, but not both.

He chose to show us the energy.

Dan McCoy

I found a pretty cool resource on iron, one of my favorite funky transition metals.

Another source of concise information on the respirocyte concept.

My thanks to my longtime friend (I avoid the term "old friend" for such a young woman) Kennita Watson for alerting me to this lecture at Stanford on 23 June 2004: "The Artificial Synapse Chip: Towards an Electronic Prosthetic Retina" by Harvey A. Fishman, M.D., Ph.D, Stanford University School of Medicine, the Director of Ophthalmic Tissue Engineering and Chief Ophthalmology Resident in the department of Ophthalmology.

Age-related macular degeneration (AMD) is the most common form of severe and irreversible blindness in the U.S. Our research program consists of a highly interdisciplinary effort between physicians, engineers, and scientists to develop a neural interface that will connect the output from a digital camera to individual retinal cells in patients with AMD, thus bypassing injured cells.

I really wish I could make this lecture, but I have a bioanthropology final exam during the very time slot this lecture occurs (6:15pm for dinner at the hospital cafeteria, 7:30-8:30pm for the lecture). If you, the reader, can attend I'd love to hear your impressions of the event.

By the way, this sounds like a skillset for the type of research physician I find really interesting:

Dr. Fishman's area of expertise is translational research that uses a multidisciplinary approach to develop novel therapies for blinding diseases in the eye – in particular, Age-Related Macular Degeneration. His research bridges the gaps between tissue engineering, surface science, nanofabrication, chemistry, neuroscience and retinal transplantation biology in Ophthalmology. His background in new technologies and medical science is diverse including bioMEMS, chip-based microfluidics and confocal and time-lapse microscopy, neuroscience/nerve cell regeneration and macular diseases in Ophthalmology. He has made contributions in the fields of microfluidics, laser-induced fluorescence detection, separation science, and biosensors.

I imagine respirocytes as minuscule objects consisting of roughly 18 billion atoms arranged in small balls about a thousandth of a millimeter in diameter. Each respirocyte is a tiny pressurized gas tank equipped with small pumps. Respirocytes are nanobots that move with the blood. In the body's periphery, they release oxygen and absorb carbon dioxide. In the lungs, they do the opposite, recharging themselves with oxygen. The exchange of gases is regulated by minute sensors. Though the respirocytes are modeled on red blood corpuscles, they transport oxygen two hundred times more efficiently than the natural item. A small syringe-full of respirocytes could carry as much oxygen as your entire bloodstream.

Robert A. Freitas Jr
28 July 2000

I crashed late last night, and woke early this morning, and am ready to do it all again today: the Foresight SAG continues.

The advice below can easily be applied to many different academic endeavors, including use in non-science classes. Here's a recipe. First, buy these pens:

• The Bic brite liner, of course. Avoid excessive markup with this. Really. Some of you may need to be told this, so here goes: what good is text that is mostly highlighted?
  
• The classic Bic "4-color pen": you can't survive without this!
  
• At least one Sharpie pen (keep one in your labcoat pocket) for marking test tubes and centrifuge vessels. I know, these have nothing to do with the method below, but a good lab geek always has one in her pocket anyway.
  
• A set of colored pencils. I use the erasable Sanford Col-Erase, but non-erasable Crayola colored pencils are cheaper and color adequately too.
  

The classic Bic 4-color pen should be in any student's pocket anyway. Annotating your own notes is so much easier when you use different colors. Here's an application to chemistry: you can draw much more easily understandable molecular orbital "balloon diagrams" (using the 90% probability surface standard or other representation of choice) if you assign colors to orbitals and stick with those colors.

The "balloon diagram method" I use:

This is pretty cool: scans of Linus Pauling's Research Notebooks taken from 1922 to 1994 (he lived 1901-1994).

As with many scientists, Linus Pauling utilized bound notebooks to keep track of the details of his research as it unfolded. A testament to the remarkable length and diversity of Dr. Pauling's career, the Pauling Papers holdings include forty-six research notebooks spanning the years of 1922 to 1994 and covering any number of the scientific fields in which Dr. Pauling involved himself. In this regard, the notebooks contain many of Pauling's laboratory calculations and experimental data, as well as scientific conclusions, ideas for further research and numerous autobiographical musings.

On Friday during his office hours, my chem prof was deeply surprised to find that I didn't yet own a copy of Zumdahl's "Chemistry", which is not our school's official text... so he gave me one of his, a new copy, the Instructor's Annotated Edition (5th)! He had an extra, so it became mine... a good, good man, and deeply flattering.

A couple of people in a chemistry forum I frequent had recommended Linus Pauling's "General Chemistry". I saw a copy in my local Border's - the 1989 Dover reprint of the 3rd edition (the last, 1971) - and flipped through it. I was impressed, so I took note of its ISBN. The shelf price was $20, but I found a pristine copy on Amazon Marketplace for half that price and ordered it. Can't wait to get it.

A caveat, by the way - and this is no hit on the book, given its age - if you're going to study coordination compounds of metals, you'll need to supplement your reading with Zumdahl, or another modern source. Although Pauling mentions the work of Alfred Werner in a sidebar of a couple of pages on the matter, he (quite understandably) doesn't mention crystal field theory & d-shell splitting (of course he wouldn't). Very highly recommended.

...especially when it involves bad things happening perilously close to me.

There's a phenomenon well known in its universality among martial artists, pilots, and laboratory investigators (and many others, though these are categories to which I can personally claim memberhip): beginners can be dangerous!

For fledgling pilots, safety comes first in collision avoidance and minimal aptitude in takeoff and landing (especially landing). Student pilots at this point truly have to be watched carefully.

For martial artists, dealing with beginners means being aware that the beginner is often not aware of how easy it is to hurt your training partner, and hence how important it is to learn how to train properly so that you don't get hurt "when it's your turn to lose" in practice. Genuinely dangerous!

Today, I had a reminder of how easily late-first-year chemistry students can be genuinely dangerous too. I'm a stickler for thorough preparation for lab investigation, which includes adequately understanding any reaction schema involved in the labwork. Today's labwork involved the generation of noticable volumes of chlorine and nitrogen dioxide gasses, the latter of which was to be generated by heating of reagents including concentrated nitric acid under a fume hood.

Well, today a couple of giggly Chinese girls (otherwise sharp but who are treating chemistry as a checklist item, a waypoint on the way to medical school) who didn't fully understand the reaction schema, were heating the nitric acid solutions at their bench! Before any of us had time to react, they'd already generated a visible cloud of white, toxic smoke. The hell of it was, they simply stood rooted where they were standing, looking embarassed. They were not embarassed that they stood a risk of death or injury, but that they'd been caught not having prepped their lab notebooks with the proper procedure! A couple of other students managed to shake them from their (not yet literal) mortification and pull them away from the danger, while my instructor and I started hitting the buttons on the emergency fume hood evacuation systems, hoping we could clear the cloud quickly and safely by drawing it across the room into the hood system (and upwards from there into the Great Dilution of the atmosphere... note that our lab building is gratifyingly free of pigeon poop for a very good reason.)

Later, I did what the instructor later noted was probably more effective and shocking coming from a fellow student rather than from him: I dressed down the girls in front of everyone else, telling them they must come into the lab prepared next time, rather than faking their way through an experiment. Funny thing was, just a few minutes before the incident I'd commented to my instructor that many of my classmates didn't seem to have any grasp of the difference between real laboratory science and ritual magic.

Oh, and several minutes later I witnessed another girl come up to the instructor asking if the open centrifuge tubes she was holding - which were continuously generating chlorine gas as a side reaction - were hazardous! Argh!

At least our labwork on Thursday of last week went without incident. You see, there was a reaction on that day which required careful control of pH in one of the test solutions containing thiocyanate ions (SCN-). We needed to maintain a particular weakly acidic environment in order to favor a certain desired product. You see, a more acidic pH would have tilted the reaction strongly to the production of HCN, hydrogen cyanide gas...

It's 4 weeks into my fourth quarter of general chemistry, and I'm deep into a weeks-long laboratory assignment involving identification of unknown cations in mystery solutions... a forensics exercise involving minute amounts of reagent, fiddly and frustrating, but necessary. It'a also a transition to the full-blown organic chemistry sequence, which I'm eagerly anticipating.

In the midst of my frustration, my chemistry professor, whose labtime desk sits next to my workbench, handed me my previous quarter's graded final exam, the taking of which marked the completion of the most difficult course in the general chemistry sequence.

I made a perfect score on that exam.

I feel really, really good right now. Really good. I've been given permission to copy that exam before I return it to my professor... and it's going right into the folder of recommendations and other papers I can show to schools and employers in the near future. Woohoo!

I'll be attending all 3 days of the 14-16 May 2004 Foresight Senior Associates Gathering in Palo Alto, California. I very highly recommend this event to anyone interested in molecular nanotechnology. If you're not intimately familiar with nanotechnology, but want to learn, I enthusiastically recommend the 8-hour "Fundamentals of Nanotechnology" tutorial session on Friday: I'll be attending myself to dust off and deepen my own understanding.

Mark Miller informs me via Orkut that K. Eric Drexler now has a personal nanotechnology website, e-drexler.com.

I was helping one of my chemistry classmates study after class this morning. Our topic of conversation was electrochemistry. My classmate's confusion was over the terminology used in voltaic cells, e.g. oxidation, reduction, cathode, anode, cation, anion, etc. It occurred to me in the course of discussion that her confusion was due to the use of the term "reduction", which simply means "a reduction in oxidation state by electron donation"; it's a useful numerical indication of that state, not of the physical configuration of the element being "reduced". I'd long ago internalized the actual meaning, so it had slipped me that to a very bright but non-native speaker of English, "reduction" would seem to indicate a physical reduction of some dimension of the affected chemical species!

I had one of those "aha" moments and drew her a diagram of what actually happens with an example species being reduced, in this case a bare proton (a hydrogen ion, H+): H+ has an oxidation state of +1, which can be reduced by an electron donor to 0. The atomic diameter of the ion is as small as a species can get, effectively equal to the proton's diameter; the addition of an electron ("reduction") drastically increases, in a relative sense, the effective atomic diameter of the neutral hydrogen (disregarding the issue of likelihood of a monatomic non-ionic hydrogen), which is "a bigger dimension", not "a reduced dimension".

Chemistry - and most of science - is full of such interesting and sometimes annoying little ambiguities which are the legacy of discovery and provisional definition. Don't even get me started on all the different symbols used to denote "energy"...

The mind likes a strange idea as little as the body likes a strange protein and resists it with similar energy. It would not perhaps be too fanciful to say that a new idea is the most quickly acting antigen known to science. If we watch ourselves honestly we shall often find that we have begun to argue against a new idea even before it has been completely stated.

Wilfred Batten Lewis Trotter, English surgeon (1872-1939)

One down, two to go: just finished my chemistry final exam half an hour ago, now time to relax and prepare myself with rest and food before my discrete mathematics exam tonight. I don't believe in cramming: I prefer to clear my mind before an exam, using the store of knowledge I've built up over the school term... that way, I know what I know when I take the test. Cramming doesn't really work, neurologically, though some people never seem to understand that observation.

It was almost funny the number of classmates who nearly physically jumped me on campus during the last half-hour before the exam, asking me questions they should have been asking the teacher weeks ago, e.g. "What does entropy have to do with Gibbs free energy?" or "What is a 'colligative property'?" or "What's the 'steric factor' in the rate constant?"

The best I could do is assure the questioners that they'd do fine, and to stop worrying: they'd be better prepared by meditating to clear their heads than to try to understand material they should have already mastered. I didn't have the heart to say, "Dude, you're so screwed!"

I took this shot two hours ago. These are the digital and tape audio recorders of a number of students in our chemistry lecture section:

Look familiar? Anyone else remember that running sight gag from the 1985 Val Kilmer flick "Real Genius"? As one writer describes the scene (yay Google, saved a bit of typing on my part):

Do you remember the scene in the movie "Real Genius" that showed students at the beginning of a university semester sitting in a large lecture room listening to the professor? As the semester wore on, one-by-one each student left a tape recorder on their seat. The scene ended with the professor's recorder pontificating to a room full of other recorders.

I found a screenshot of that scene, which looks amazingly like our chem lecture hall, down to the same phenolic resin desktop:

Whoa. Life converges on art. Fortunately, ours is a very dynamic professor... most of the students are simply trying to capture his superb lectures for replay later. As a matter of fact, on most days the professor records his own lectures with studio-quality equipment for posting on his personal website. If only more of the good ones did that, we'd have more "Feynman Lectures on Physics" preserved for posterity.

Today in lab, a couple of people broke the "no food or drinks in lab" rule. My prof - whose lab desk is next to my lab bench - and I reacted not by stating the obvious, but by saying, "Hey! Let's measure the pH of those drinks!" Why not? We all had $600 Accumet pH meters in front of us. So, we measured the pH of the following solutions:

• Gatorade X-Factor: pH 3.089
• Arizona Iced Tea brand Green Tea w/ Ginseng & Honey: pH 3.424

That's pretty interesting, since at first approximation, I'd expected any Gatorade solution to be isotonic, at a physiologic pH of ~7.42 or so. Not so, but given that the ingredients label lists citric acid and its conjugate base sodium citrate (a buffer solution), no big surprise: it's almost exactly the pH of a 0.100 M solution of acetic acid (a weak acid, with a Ka of 1.737 x 10^-5). The Arizona Iced Tea also has citric acid in its ingredient list, but no conjugate base listed (though it undoubtedly exists in solution).