Wednesday, April 28, 2010

Learning years of science research in five minutes

I spent Friday contemplating nuclear waste, parallel universes, and psychopaths.

Usually I don't jump around thinking about those topics, but during Big Ideas for Busy People, an event preceding the Cambridge Science festival, along with nearly five hundred other attendees I learned about these topics and more all within the course of two hours.

In brief and condensed presentations, ten scientists spoke about whatever they liked in their field of expertise. For example, George Church provided a set of reasons why synthetic life is important; Angela Belcher described how genetic information can be used to make structures without DNA; and Marc Hauser presented us with a philosophical question, asking us whether people who do bad things are actually evil by birth or evil by actions.

What I especially appreciated was that each speaker brought their own style to the talks, not recycling presentations from other events but tailoring what they said to the task of talking to the public for precisely five minutes. Their methods of presenting were all rather different - some used humor to get their point across, others called upon the audience to participate - but everyone was clearly enthusiastic and excited about their topics.

Nearly all the speakers went a few seconds past the five minute buzz, but most skillfully managed to pass along their main points within the time limit. They all spoke fairly quickly, seemingly keeping the time constraint in mind and trying their best to express as much as possible. I wouldn't suggest increasing the time limit though, since the time pressure forced the scientists to focus on concepts instead of getting bogged down in details.

Unlike standard academic lectures, the audience had the chance to ask questions for five minutes after each speaker's presentation. Plenty of good questions came up, some asking for clarification on points, like why universes are spherical, but others asked broader questions such as whether we could just dump nuclear waste in the oceans to be folded into plate tectonics. The audience might have been mostly adults, but one particularly striking question on the number of parallel universes came from the ten year old son of one of the speakers, Max Tegmark.

Given the experimental nature of the event, its location in The Laboratory was particularly well-suited. The large room was filled in front with couches, but as more and more people came chairs were set up to the very back edges. If Big Ideas can draw such a big crowd the first time it runs, maybe if done again it'll have to be in an even bigger setting.

Video of the entire event should be posted on the Cambridge Science Festival's web site in upcoming weeks, and hopefully the Festival will put on another Big Ideas for Busy People next year!

Monday, April 26, 2010

Lunch With a Laureate: Dr. Richard Schrock

Environmental issues are very popular these days, and with good reason. I've heard many ideas suggesting how we can improve our environment or at least minimize the damage we do to it, ranging from driving more fuel efficient cars to using solar and wind powered energy. An equally important, though less publicized frontier for improving the environment, is in the production of chemicals. The chemical processes that produce fuel, drugs, and plastics also produce toxic waste. One way to improve the environment is to substitute a different chemical reaction which would produce the same end substance, but without the dangerous byproducts. Unfortunately, such "green" alternate reactions do not exist for many current manufacturing process, but scientists are hard at work to change that reality. In 2005, MIT’s Richard Schrock won the Nobel Prize in Chemistry for developing one such new reaction.

Schrock co-developed a reaction in organic chemistry called olefin metathesis, which is more environmentally friendly and efficient than alternative methods in the production of drugs, fuels, and plastics. This reaction is often compared to a dance, where pairs of molecules switch partners and bond with other molecules. You can watch an animation of the chemical reaction here: The dance analogy is so apt in describing Schrock's reaction that his Nobel Prize Diploma included a colorful painting of dancing people. You can view the diploma here:

Schrock's reaction has been adopted by companies such as Shell Chemicals in the petroleum industry and Materia in the pharmaceutical industry. Shell Chemicals uses olefin metathesis to create chemicals which it advertises as being useful for cooling, lubrication, detergent, and waterproofing. Materia sells chemical compounds created via olefin metathesis called “pharmaceutical building blocks,” which can be used to develop new drugs. Olefin metathesis also benefits the oleochemical industry, which produces the vegetable oils and fats used in food, cosmetics, and pharmaceuticals. It is remarkable what a far-reaching influence a single chemical reaction can have with regard to industrial efficiency and environmental improvement.

You can meet Richard Schrock on Friday, April 30 from 12 Noon – 1 pm at the MIT Museum, where he caps a week-long “Lunch with a Laureate” discussion series. You can ask him questions about his research, the award of the Nobel Prize or the multiple applications and implications of olefin metathesis. Even (especially!) if you missed the others, be sure to catch this last “Lunch with a Laureate” in the 2010 Cambridge Science Festival!

Sunday, April 25, 2010

Hotter Than Your Hottest Date

Ok, maybe it’s not the kind of hot date you’re thinking of, but this hot date will be pretty hot. It is a date with your one and only sun! It’s always there, but have you taken the time to explore it? Do you even remember it’s there? Do you even give it the time of day? Many cultures have religions that worship the sun. However, many of us live day-to-day taking our sun for granted.

Maybe we don’t think about because it is 93 miles away from us on earth. Maybe we don’t think about it because our planet earth seems so amazing that we think it’s probably the most amazing thing in existence. We may think earth is cool, but the sun might just be cooler.

First off, compared to earth, the sun is massive! The sun is more than 300,000 times heavier than the earth. It would take more than 100 earths to span the entire width of the sun. And, more than one million earths would fit in the middle of the sun! Although it is huge, there are other stars out there that are hundreds of times bigger than the sun.

Ever thought about what it’d feel like to be on another planet? Well, if you were able to be on the sun, you would feel massive. The gravity on the sun is 28 times more than on the earth. Someone that weighs 150 pounds on earth would weigh 4,200 pounds on the sun.

We think of it as our source of natural light and heat but do we even know anything about how it works? Did you know light from the sun takes about 8 minutes to arrive at earth? If the sun ever stopped shining, it would take us 8 minutes to realize. Pretty scary, huh? It radiates heat and shoots off a steady stream of charged particles, called solar wind, at a rate of 280 miles per second through the solar system. Solar flares, another type of wave of charged particles, also come out of the sun. Why are they important? Well, they can disrupt all satellite communications and knockout all electricity on earth.

And, by the way, this is what the sun looks like up close and personal...

Just last week we celebrated Earth Day. When do we celebrate Sun Day? Every week? (Get it, Sunday?) Just kidding. In fact, we do not have a popular national holiday to celebrate the sun. Why is that? I do not know. If the sun ever decided to stop working or decided to start over-working, we’d all be dead. Basically, all of life depends on the sun’s normal functioning. The sun is about 4.5 billion years old. And, it’s only expected to shine for another 5 billion years. Let’s start appreciating now.

On April 27 through May 2, the Cambridge Science Festival is hosting a “Solar Lunch” on the plaza in front of the Museum of Science from 12pm-1pm. It will be a great opportunity to learn about the sun and actually see parts of the sun up-close and personal. Let’s make it a date, a hot date. I am not sure if food will be provided. Regardless, come out, meet new people, learn a lot, and give some attention to your one and only sun. See you there! (Weather permitting.)

I found the facts I included on the sites below. Please visit them to learn more cool facts about the sun.

Saturday, April 24, 2010

Holograms: More than just pretty pictures?

At this point, you may be wondering, “Why does MIT, a university known for driving innovation, care about and collect pretty 3D pictures?” Well, it turns out that holography has some pretty important real-world applications, such as data storage.

As you probably know because you’re reading this blog, we live in an age of information. Of course, this explosion of information wouldn’t be possible without ways to quickly store and transfer large quantities of data. So far, we’ve been relying on conventional optical storage technologies (e.g. CD’s, DVD’s, Blu-Ray) to handle this need. While current storage needs are being met, storage technologies must continue to improve in order to keep pace with the rapidly increasing demand.

Top view of a CD and its spiral of bitsSide view of holographic disc

This is where holography comes in. Although optical storage technologies have improved by leaps and bounds since the advent of CD’s (DVD’s can hold 15 times more information than CD’s and Blu-Ray discs can hold 10 times more than DVD’s), they are still limited to recording information on the surface of a disc. They all use lasers to etch a spiral of individual bits (1’s and 0’s) onto the surface of a recording medium, but holographic data storage uses lasers to etch pages of bits throughout the entire volume of a recording medium. Theoretically, holographic discs can store 40 times more data than Blu-Ray discs can. How exactly is this done?

Recording hologram of SLM

In my first blog post, I went over the process of using holography to make images of physical objects but how would we go about using holography to store information that lives inside of a computer and that we can’t actually touch or see? Suppose that you want to store a movie onto a holographic disc. Your computer converts the data into a sequence of bits and sends this to a spatial light modulator (SLM). The SLM is a screen that arranges this sequence into a page of bits. Each bit is represented by either a black or white square (0 is black; 1 is white), so that the LCD screen looks like a checkerboard of black and white squares. Now that the data is rendered into a visible form, we can make a hologram of it. Once again, a laser beam is split into a reference beam and an object beam. The object beam goes through the SLM and comes out carrying the pattern of the image that was displayed on the SLM. The two beams eventually meet at some place within the recording medium (e.g. at the surface or in the middle), which records the interference pattern of the two beams. To read a page of data, you recreate the object beam by illuminating the recording medium with the reference beam. The recreated object beam hits a charged coupled device (CCD), which is a sensor that is connected to a computer. The computer takes a page of black and white boxes and converts them back into a string of bits and back into data.

Reading hologram

Note that the reference beam must approach the SLM from the exact same angle that was used to write a page of data; otherwise, the phase of the beam will be different and you will recreate the wrong object beam. Because you can recreate different object beams by varying the phase and wavelength of the reference beam, it is possible to store multiple holograms in the same volume of recording medium. You can also stack holograms on top of each other by using mirrors and lenses to specify the location of the interference pattern within the medium. So far, the company InPhase Technologies was able to cram 500 Gigabytes into one square inch of medium that was as thick as a CD. Based on this figure, a disk the size of a CD could hold up to about four Terabytes (one Terabyte = 1000 Gigabytes) of information. With this technology, we could fit the entire printed collection of the US Library of Congress onto three discs.

Searching hologram

Not only are holographic discs superior to CD’s, DVD’s, and Blu-Ray discs in terms of storage capacity, they also permit high data transfer rates. One page of data (equivalent to 125 Megabytes) can be read with a single flash of light, whereas CD players are limited to reading one bit (1/8th of a byte) per flash of light. Since multiple holograms stored in the same volume of medium can be read by altering the angle of the reading laser, high transfer rates are possible since the angle of a laser can be manipulated quickly without inertia, unlike a CD player which relies on a mechanical part to move the laser back and forth. Another advantage of holographic storage is that it can be searched extremely quickly. If you illuminate a disc with an object beam, you will reproduce the corresponding reference beam and its angle, which immediately identifies the page on which the information is stored. This means that database searches can be done using physics rather than software.

So if scientists already know how holographic data storage works and have even built a few prototypes, why haven’t we seen any of these systems on the market today? In this technology, lasers have to be directed and aligned very precisely. Any slight deviation would make it near impossible to store and retrieve error-free data. For this reason, the components of the system are extremely expensive to manufacture quickly and in large quantities. Another issue arises out of the ability to stack multiple holograms. When a computer attempts to read a disc’s data, the reference beam will reproduce its corresponding object beam, but will also produce a lot of noise from the other holograms that are stacked on top of it. The more holograms there are, the more noise there will be. Noise makes it difficult to retrieve correct data. It’s like trying to watch TV with poor picture quality. You might be able to discern a few shapes here and there, but you can’t be absolutely sure of what you’re seeing. Theoretically, thousands of holograms can be stacked in a disc as wide as a CD, but it doesn’t make sense to do that if you can’t retrieve the data. The developers of this technology need to figure out how to reduce the noise as much as possible before the product can be commercialized.

A Berry Efficient Solar Cell

A short walk through the Cambridge Science Festival will reveal an important fact: the festival is not just for science. It’s for technology, presentations of innovative ideas, and fun, hands-on activities. The CSF offers such a wide variety of activities that it has attracted cool, sometimes strange, modern technologies. Among the strangest is the blackberry solar cell - no, not a solar cell for the BlackBerry phone, we’re talking about the actual fruit - small seeded dark berries whose juice can be used to harvest energy from the sun. To see this technology in action and make a solar sell for yourself (for free!) head over to

the Cambridge Public Library at 449 Broadway between 12:30pm - 1:30pm or 2:00pm - 3:00pm for “The Blackberry Solar Cell: A green Chemistry Activity.” This activity is definitely for all ages.

If blackberries can be used to capture solar energy, what other unusual uses might fruit have? Perhaps a postage stamp made out of lemon rind, or a dress made out of apples?

An investigation of the many uses of fruit first reveals the most common uses: food, beverages, gifts and decorations. After all, where would we be without grape juice, fruit baskets, and holly at Christmas?

After a bit more research, increasingly unusual uses for fruit show up. Some uses seem to be completely unrelated to fruit. The following products are good examples: various type of pain killers - opium which contains morphine and codeine is made from the fruits of opium poppy; dyes - cherries and walnuts can be used as natural dyes; musical instruments - gourds are dried and hollowed out to make instruments; skin care products - supposedly, applesauce makes a great facial mask; and leather polish - banana rinds will do the trick!

Looking further into fruity practices, medicinal applications seem quite common. It is amusing, or possibly disturbing, that nearly every fruit has been claimed to have some medicinal benefit. Cranberries heal UTIs, rose apples are a brain and liver stimulant, figs cure warts, and goji berries boost your immune system. This widespread claim that “fruit is medicine” either suggests that fruits are generally good for one’s health and contain vitamins and minerals that promote wellness, or it suggests that people are desperate in the search for cures to yet incurable diseases. Most effects of fruit on health are not scientifically, clinically, or even methodically tested/proven to be beneficial. Therefore claims of healing fruit should be taken with a grain of salt whereas a product like a solar cell can be shown to work without doubt. Either way, it can’t be denied that fruit has had a large effect on the health of the world, whether as a medicine or simply a good source of nutrition.

After taking a look at some alternative uses of fruit, a blackberry solar cell is undoubtedly the most unique. Imagine a small electronic device whose materials include (1) indium tin oxide conducting glass, (2) iodide electrolyte solution, and (3) blackberry juice. That third ingredient is slightly shocking! However, the blackberry juice plays an important role in the solar cell, acting as a dye that first absorbs the light from the sun that the solar cell can then convert to electricity. If you’d like to see this for yourself, head over to the Blackberry Solar Cell event.

It's pretty clear that fruit is not common in electronics. Why would someone think to use blackberry juice as a solar cell? In an increasingly green society, looking toward more natural and non-toxic materials is beneficial for the inventor and the environment. This presents an opportunity to introduce more natural products into modern technology, like trees grown for biomass to create renewable energy, or corn grown for ethanol. These green technologies already exist. What will be next?

Apple dress adapted from this photograph.

Thursday, April 22, 2010

Bottled Water vs. Tap Water -- Who Wins?

...Is there a difference? Should you prefer one over the other?

Well, let’s start with this fact: some of the bottled water you buy is actually tap water. That’s right, tap. While bottled water may come from more pristine-sounding places like natural springs and wells, other bottled water is simply dressed-up tap water. Sure, it might have undergone some extra treatments, such as dechlorination and some tweaking of mineral content, but it is still tap water placed in a fancy and portable plastic container.

Let’s do some math first. Water from the tap is dirt cheap. Water from the bottle is much less so. Typically, buying a bottle of water at a vending machine or convenience store costs you at least $1 per half-liter bottle. That’s $2 for a liter of bottled water, and there are about 3.8 liters in a gallon. This puts us at $7.60 for a gallon of bottled water. Now compare that to current gas prices of around $2.75 per gallon. Makes bottled water seem like a rip-off, doesn’t it?

Water doesn’t have to be that expensive, even with purification treatments. When you’re buying bottled water, you’re paying less for the water and more for the cost of bottling, packaging, shipping, marketing, and of course, company profit. Not to mention, buying bottled water means producing more waste in the form of plastic containers. The more tap water and less bottled water you drink, the better you are being to the environment.

Why do people bother with bottled water then?

For many, it’s a matter of hygiene. Whether the source of the water was from a spring or a tap, bottled water comes with a reputation for being cleaner and thus healthier; but is that actually the case?

In America, where the public water infrastructure is quite good, the answer is no. Experts trusted by the bottled water industry agree. According to a report by ABC News 20/20, “Even Yale University School of Medicine's Dr. Stephen Edberg, the person whom the International Bottled Water Association told ‘20/20’ to talk to, agreed that bottled water is no better for you. ‘No, I wouldn't argue it's safer or not safer.’” Moreover, the safety of tap water is supported by studies: one 4-year study by the Natural Resources Defense Council (NRDC) found that tap water is often subject to even more stringent regulation and testing than bottled water. Not much to fear from tap water then.

Conclusion: in the U.S. it is not necessary to buy bottled water out of health concerns.

However, there are those who claim that bottled water just tastes better. Is that actually the case too? Blind taste tests of bottled vs. tap water have been favorable towards tap water, but why don’t you taste the results yourself at this year’s Cambridge Science Festival?

At the Science Carnival on Saturday, April 24 between noon and 4pm, the Cambridge Public Library will be holding the event Bottled Water v Tap Water, where you can learn more about the differences and similarities between the water from the bottle and from the tap—all while sipping on a refreshing cool drink of water.

This event is sponsored by CDM.

Image Credits:
• Bottled water image modified from Brett Weinstein’s photograph.
• Tap water image modified from Alex Anlicker’s photograph.

A Carnival With No Clowns?

When I think of attending a carnival on a Saturday afternoon, I think of clowns, cotton candy, farris wheels, and amusement booths. The Cambridge Science Festival is hosting a “Carnival” this Saturday as a kick-off event to their 10-day festival. But, there will not be clowns or cotton candy or any of the things that first come to mind when I think of carnival except for the booths. What can you expect from this so called “carnival”?

When you walk up to the attraction booths, you will not be handed a handful of darts and asked to pop the water-balloons to receive a prize. Rather, you may be asked to spit in a cup to sequence your DNA or maybe asked to peek into a suitcase that contains fiber optics made out of Jell-O.

According to the festivals website the “Carnival” will feature many interesting attractions and hands-on workshops that will allow you the opportunity to make ice cream using liquid nitrogen, sequence your DNA, build electrical circuits, explore your brain, learn about cancer drug development and sustainability projects, and much much more.

You will not attend the traditional clown show; rather you will attend a Laser Show to celebrate the 50th anniversary of the laser. Instead of watching clowns juggle, you will see chemists make science come to life.

When I go to a carnival, I want to see clowns and I want cotton candy. But, I guess, as a scientist, I could settle for something else. Do you think carnivals need clowns and cotton candy? I will leave it up to you to decide this weekend.

The carnival will be from 12pm-4pm this Saturday (April 24th) at the Cambridge Public Library, 449 Broadway. There will be free shuttles from Harvard Sq, Cambridge Public Library, Museum of Science, Kendall T, Stata Center, MIT Museum, and Central Sq. Please visit the Cambridge science festival web page for more information.

Wednesday, April 21, 2010

Spit In A Cup And See Your Future

Yup, it’s really that simple. This weekend come spit in a cup and learn about your DNA, which ultimately can reveal to you your future. How? Well, everyone has DNA. It is our genetic code; many refer to it as the “blue print” of human life. It makes you, YOU and me, ME. The difference between our DNA is the sequence of the chemical bases. All DNA is made up of four chemical bases: Adenine (A), guanine (G), cystine (C), and thymine (T). We each have an estimated three billion of these bases in our genome. They are organized in an infinite amount of sequences throughout our bodies and in turn it makes every individual unique. The sequence is specifically referred to as the genome. Our genomes are unbelievably huge! Your entire genome fills 200 1,000-page New York City telephone directories. And, if you unwrap all the DNA you have in your cells, you could reach the moon 6,000 times!

Your DNA sequence, or genome, can reveal a lot. Your sequence is completely unique to you. No one else in this world has the same DNA sequence as you do. However, some parts of your genome are like other peoples. This commonality, along with other research mechanisms, has allowed scientists to research what these sequences code for, in other words, how these sequences affect your body. Scientists have been able to identify specific sequences that flag diseases and health traits. Additionally, sequencing DNA can reveal information about ancestry and genealogy.

You have the opportunity to sequence a part of your genome this weekend at the Science Carnival featured at the Cambridge Science Festival. I know what you’re thinking, it sounds like a cool opportunity but it’s going to be complicated. I promise you it won’t be. You will use a common, easy way to extract your DNA –you will swirl salt water in your mouth and then spit it out into a cup. This extracts DNA from your cheek cells. You and a lab technician will amplify a fragment of your genome and then sequence it in a DNA sequencing machine….and, wa-la! You will be able to see the very code that dictates your body, makes you the person that you are, and ultimately determines important aspects of your future, like your health.

This amazing opportunity is being provided by DIYbio Boston at the Boston Open Source Science (BOSS) Lab on April 24th and 25th from 12-4pm. The process takes approximately six hours but it can be broken up over 2 days. There is a price you will have to pay, 40$. The BOSSlab is located at 339R Summer Street, Somerville, MA 02144. For more information on the event, please visit the event’s website at

To learn more cool facts about DNA, please visit this website where I found the cool facts I included in this article:

Thinking about Thoughts

The human mind does an incredible number of even more incredible things. Take, for example, the age old act of bartering. Whether trading ears of corn for livestock, or complex corporate negotiations, a large part of human enterprise has relied on our ability to think about others’ specific desires and intentions. We want what is best for us and our family or community, but realize that we need to compromise because the other party wants the same. Additionally, the other party may hold a grudge, or be ignorant towards current market values, and so on. All of this amazingly complex analysis happens at lightning speeds within the mind, while we haggle prices or make offers.

We use this complex ability every day, and it has drawn the attention of many scientists. According to MIT Professor Rebecca Saxe:

“Thinking about other minds is the foundation for both personal relationships and societal institutions, and the human capacities to read and write fiction, to teach skills and pass knowledge down generations, and to make moral judgments, especially to forgive accidents.”

The human brain and mind (which are not necessarily one and the same) are very active fields of research, and comparatively young. Saxe is one of many researchers investigating how we think about other peoples’ minds. A particularly elegant experiment done by H. Wimmer and J. Perner in 1983, dubbed the “Sally-Anne test.” According to Saxe:

“A preschooler is presented with [...] two main characters, Sally and Anne. He is told that Sally has a ball, that she has put the ball in a brown basket and gone outside; that Anne takes the ball from the basket and plays with it inside the house and then puts it in a green box; and that Sally is now coming back inside to get her ball. Where, he is asked, will Sally look for her ball?

We know that Sally will look for the ball in the brown basket: that is where she put it, and she thinks it is still there. Five-year-olds see it the same way: they breeze through the false-belief task. Not so three-year-olds. The younger children consistently predict the opposite: they expect Sally to look for her ball in the green box, where the ball really is. It's as if the three-year-olds cannot take Sally's (false) belief about the ball into account in predicting her behavior.”

So, somewhere along the line in human development, we learn how to think about people who have minds just like our own. This ability to infer and reason about another person's states of mind is called a 'Theory of Mind' (ToM). We can ask: “Do we learn our Theory of Mind from interactions with people, or is it an inherent, instinctual quality?” This is one of the questions that Saxe’s research hopes to address.

Concretely, Professor Saxe uses multiple kinds of brain imaging methods to see if there are specific mechanisms present in the physical brain that correspond to our ToM. For example, fMRI imaging combines normal MRI, which is capable of scanning the brain in incredible detail, with oxygen level analysis, which corresponds to activity in the brain. So, using fMRI scans, Saxe’s research can pinpoint areas of activity when subject are presented situations where they must employ their theory of mind.

“The brain regions involved in Theory of Mind are incredibly robust. We can find the same regions, in 90% of individual subjects, after just 20 minutes of scan time. [...] The 'Theory of Mind' regions thus offer a rare window through the brain to the mind.”

The implications of her work are far reaching. Philosophers have long debated the relationship between “the mind” and “the brain”, and this work may start to uncover the strings that hold them together. Additionally, her methods provide a window into things like Asperger Syndrome and Autism, where people experience severe difficulty in social situations where ToM is needed.

If you’re interested in Professor Saxe’s ideas you have an amazing opportunity to hear her talk about them this coming Friday evening, at “Big Ideas for Busy People!”. I heartily encourage you to attend; nothing compares to hearing the ideas straight from the visionaries themselves.

Tuesday, April 20, 2010

How to Watch a Laser Show

This Saturday, the Cambridge Science Festival opens with a lunchtime laser show. This is the final post in a series of posts designed to familiarize you with lasers.


Interview with an Artist

Joseph Choma is a student in Design and Computation at the MIT School of Architecture and Planning. He will present a special exhibit, “Design for the Ideal Polling Booth,” at the second floor of the MIT Museum from Saturday, 4/24 to Sunday, 5/2. He will personally be available for discussion by his exhibit on the second floor of the MIT Museum on Sunday, April 25th, from 1PM to 3PM. I recently got the chance to have an e-mail interview with Joseph, and here’s some of what we talked about.

Christine: Tell me about your project.

Joseph: The project is called, Design for an Ideal Polling Booth. Its intent is to provoke thought and awareness on how easy it is for us to take seemingly little things like a "polling booth" for granted. The act of voting was once a fiercely aggressive act, which did not always take place within a polling booth but sometimes at a public polling place. During the 1800s, it was normal for violent disputes to ignite at these public events. Optimistically there is a hope that by expressing the polling booth's significance, people may walk away from the exhibit with a more serious stance on voting, and learn to appreciate their rights.

Christine: What are the best features of your polling booth?

Joseph: The best features resonates on the surface experience. A surface can have a texture, but at some point if that texture extends far enough out into space, it's depth is no longer perceived as a two dimensional, but rather it becomes a spatial threshold boundary. This polling booth defines a threshold boundary with quills or spikes that radiate around a common center point. This pushes a viewer to step away from the booth while increasing the personal space and comfort for the individual voting inside. Architecturally, it sets a bound between the viewer and the user.

Christine: What was the most frustrating part of working on this project?

Joseph: It was particularly difficult to translate my digital design into a physical structure. Parametric design software doesn't care how many unique modules your design has or what physical material the design is composed of. In the end I realized perhaps it is better not to just try to recreate what I have designed in the computer as accurately as possible but rather to re-look at the project through the lens of the physical material. MIT Professor George Stiny describes a design process where you can embed anything that you see without being constrained by memory or a fixed universe. I tried to limit my digital bias and memory, so instead, I asked the material: what can it do? what does it want to be? and how does it want to be formed? This led me to an unusual hybrid fabrication process which combined digital fabrication connection accuracies with handcraft material manipulations.

Christine: Where did you get your project idea from?

Joseph: When I began working on this project the polling booth concept wasn't even in my mind. I began by “playing” with a buckyball. I drew diagonal lines off the circle's center points, and then I suddenly tried extruding those curves to a point. I realized that I had created a form of volume packing structure, and this gave me the idea to try to embed other forms into the system. I went on to pack vaults into the structure, having them radiate around a common center point. By embedding vaults into the structure it redefined the exterior boundary with what appeared to be spikes or quills. When I began to translate the digital design into the physical world, the definition of vaults became dropped and instead it became about making literal spikes. At some point, when I was trying to understand what this strange space could be, I decided to reposition it as an art piece, calling it a "Polling Booth" brought new intellectual content to the piece – like when the artist Marcel Duchamp labeled a urinal as a fountain.

Christine: What lies ahead for this project?

Joseph: This piece began to spark a notion that the inner boundary and the outer boundary of a surface could each define their own formal figure due to the project's unique "spikes." By defining that formal figure not even within the depth of its own surface thickness but rather within the illusion of thickness by having geometric texture become spikes is still an interesting concept to me. The fabrication process of using digital technologies to help control hand crafted connection accuracies still excites me as well. I began the fabrication techniques at the object scale and now at the installation scale, and next I would like to prototype at the architectonic scale (e.g. create a larger-scale model). I am also interested in composite materials as well as partially fixed and flexible molds.

Christine: What is your favorite project that you've ever worked? Why was that your favorite project?

Joseph: My favorite project is always the project I am currently working on, because if it wasn't why would I be working on it? The next project I work on should be “better” than the last, or at least that's my hope.

Christine: What advice would you give for someone wanting to go into design?

Joseph: In order to design you need constraints. Tools influence the way in which we design. This influence should not be obsessed about but you should also be conscious of the limitations of the medium. An individual should use the constraints of a tool as a mechanism to generate new unpredictable ideas. Don't try to preconceive a vision in its entirety, have faith in the medium you are exploring, and stay open minded. Be patient, keeping making and looking.

Saturday, April 17, 2010


The Truth about Phantom Loads

It’s possible that you might be paying for extra electricity without knowing it. You may have already cut back on your energy consumption in the typical ways, replacing light bulbs and purchasing energy-efficient appliances. Test your knowledge of home energy efficiency at the Energy Efficiency Game Show from 12:00 noon - 4:00 pm on Saturday April 24th at Cambridge Public Library, 449 Broadway, as part of the Science Carnival at the Cambridge Science Festival.

So is it possible that you might still be paying more for electricity than you actually use? Imagine this scenario: settling down on the sofa during a calm winter evening, you turn on your energy efficient floor lamp to begin peacefully reading,

Green Your Home All-In-One: For Dummies.

Just as you get to an exciting section on combination compost/recycling units, an intrusively loud noise erupts from the neighbor’s open window ripping into your thoughts. You look with disgust at their wide-screen television (150 watts) playing on full volume while their gas fireplace (1,500 watts) sends heat into the room and straight out the open window. Every light inside the house is on, not to mention they

are using incandescent bulbs (1,000 watts). The microwave (1,000 watts)

is heating some leftovers that you assume have been in the refrigerator (100 watts) for at least a week

while their

• cell phones charge (20 watts)

• their computers compute (100 watts)

• the DVD system plays (20 watts)

• the printer prints (50 watts)

• and the dishwasher washes (1200 watts)


5,140 watts is the power you’d use to do 17 pushups per second. That’s 1000 pushups per minute! If they had to power their own house by doing pushups, at least they’d be in shape.

Your neighbor is wasting so much electricity, yet you manage a measly total of 10 watts just for your reading light. (You are wearing a parka because you don’t use heating anymore, and you gave also up refrigerated foods.) When you turn out the lights to call it a night, you think you’re using no power at all. Think again! It turns out the devices you have plugged in are using electricity without your knowing it. Your television and your microwave are off and yet they are leaking power from the outlets. They are acting as phantom loads.

Phantom Loads

Phantom Loads, also known as standby power, leaking electricity or vampire power, is the power that leaks into electronic appliances even when they are in the off or standby mode. Most electronics operate in standby mode the majority of the time, yet are still using power. A desktop computer for example uses 21 watts in sleep mode. When it is completely powered off, it still uses about 3 watts. You’d have to unplug the computer completely to stop this leakage! Take a look at this website for leakage rates of some typical household appliances.

Living in a house without heat or refrigeration, as in the scenario above, might be unreasonable. However, adding up the leaking power from some common appliances give surprising results.

These phantom loads total up to 23 watts with all appliance completely off. Sleep mode can add another 15 watts to a computer or 10 watts to a DVD player. The average US house uses around 1000 watts which means phantom loads account for more than 2% of the energy used by households. By some estimates (, phantom loads comprised 5% of the entire US household power consumption amounting to a total of $3.5 billion dollars annually spent on wasted power. If the quantity of wasted power isn’t shocking enough, the amount of wasted money should be.

How the phantoms be stopped?

Surge protectors help. Plugging appliances into surge protectors and then shutting these off at night will eliminate phantom loads. Alternatively, unplugging the appliance would do the trick. Also, shutting electronic gadgets off completely rather than leaving them on sleep or standby cuts power consumption enormously. Again, replacing appliances with energy-efficient versions is a good way to contribute to energy conservation and to save $$.

This website tells you how you can check whether your home has phantom loads

Check out these websites for more information on phantom loads:

Tuesday, April 13, 2010

What's in a laser?

Eleven days from today, the Cambridge Science Festival opens with a lunchtime laser show. This is the third in a series of posts designed to familiarize you with lasers -- before the showtime lights dim.


Lunch With a Laureate: Dr. Jack Szostak

Nobel Prizes are sometimes awarded years after the research leading to them was conducted. Often the awarded scientist has moved on to other areas of research. Such is the case with Dr. Jack Szostak, a genetics professor at Harvard Medical School and at Massachusetts General Hospital, who received the Nobel Prize in Physiology or Medicine in 2009 for research that he conducted in the 1980s. He won the Prize for his discovery of telomerase, an enzyme which is critical to the replication of DNA.

It turns out that DNA cannot be copied all the way to the end of the strand. So if we had nothing to protect the ends of our chromosomes, they would become smaller and smaller each time they replicate. Thankfully, shrinking chromosomes are avoided by a wonderful protective mechanism called a telomere. A telomere is a non-coding stretch of DNA at the end of a chromosome which protects the chromosome from losing important information each time it is copied. Because the telomere does not code essential information, it is okay that it is not fully replicated. However, if the telomeres were to get shorter and shorter each time DNA was copied, eventually the telomeres themselves would cease to exist and then there would be nothing protecting the important information from being deleted.

This is where Szostak's discovery, telomerase, comes into the picture. Telomerase maintains the length of the telomeres, ensuring that the protective cap at the end of our chromosomes remains strong. It turns out that telomerase is involved in the processes of aging and cancer. When the telomerase breaks down, genes are not copied well, causing aging. Hyperactive telomerase has been shown to be responsible for the rapidly multiplying cells of cancer. The discovery of telomerase is so important that it was even in my introductory biology textbook.

In the almost thirty years since Szostak made his discovery of telomerase, he has moved on to other areas of research. Currently, he is intrigued by how a bunch of chemicals turned into the beginning of life billions of years ago. His lab is developing an artificial cell that can undergo Darwinian evolution, modeling the early development of life. Szostak's model of the evolutionary cell consists of two self-replicating parts: the genetic material inside the cell, and the membrane enclosing the cell. The genetic material needs to allow the current cell to be copied, but it must also allow for variations to evolve into their own unique cells. This research is exciting, as it will allow us to better understand the early stages of life by seeing evolution in action. Szostak also hopes that his research on early cells will further our understanding of how cells work today.

You can meet Jack Szostak on Wednesday, April 28th at the MIT Museum as part of the weeklong Lunch With a Laureate series. He'll be available between 12 Noon and 1pm for an informal discussion about his life, his work, the Nobel Prize, and anything else you want to ask him. Bring your questions about telomerase, cells, aging, and the origin of life. Also, don't forget to bring your lunch!

Friday, April 9, 2010

Big telescopes; Bigger Questions; and Really Big Mistakes

Imagine its 1930, and you’re a veteran Harvard astronomer, talking to ordinary folk about your work.
It’s the most exciting time in your field since Isaac Newton, but its surely sort of embarrassing too.
Those folk might reasonably say to you: “Hey, just ten years ago, most of you people thought our Milky Way galaxy was the whole universe – and now this Hubble fellow tells us there are billions of galaxies just like ours out there.”
Or – referring to Cecilia Payne - they could say: “What’s more, you people all thought the stars were made of IRON, like my CAR, until just last year, when a LADY – someone’s assistant! – proved they’re made of hydrogen gas, which couldn’t be more different! Have you got ANYTHING right?”
Now – in 2010, after a decade of equally stunning new discoveries – Harvard’s astronomers face a remarkably similar time of excitement and embarrassment.
Embarrassment, because – until very recently - astronomers thought they at least knew the basics of what the universe was made of.

Thursday, April 8, 2010

We are who we friend

Want to be happy? It might be as easy as surrounding yourself with happy people.

Nicholas Christakis, Professor of Medical Sociology and of Medicine at Harvard University, examined thousands of social connections and found that happy people tend to associate with happy people, while lonely people tend to associate with lonely people.

The effects our friends have on us extend further than that. Smokers and obese people are more likely to group together, affecting each other through their mutual decisions.

In colorful, branched diagrams, Christakis maps out social networks and uses them to examine how we group together. Below for instance is what could be called a web of happiness, showing happy people in yellow, intermediate people in green, and unhappy people in blue, with the other colors indicating different types of social relationships. The different types of people tend to cluster together, as can be seen by the fact that most of the yellow sections group together and most of the blue sections group together - happy goes with happy, unhappy with unhappy.

"Happiness in a Face-to-Face Network in 2000," from Christakis paper "Dynamic Spread of Happiness in a Large Social Network: Longitudinal Analysis Over 20 Years in the Framingham Heart Study."

This is the power of social networks, the real life web of connections we make with other people. As much as we consider ourselves to be independent individuals, Christakis's research shows our friends, family, and coworkers influence us more than we realize.

Our behaviors model those around us because the people we associate with affect our expectations of what is normal and we start to unconsciously imitate them. Just like viruses can move from one person to the next, thoughts and feelings can move like an infection through an entire social network.

Those we're closest to influence us the most, and our influence on others wanes as we travel further through our social network. But in our tangled social web, Christakis has found that even people you've never met can affect your life.

Christakis is just one of the ten scientists speaking at Big Ideas for Busy People, a Cambridge Science Festival event where leading researchers give five minute presentations each for a general audience. The title for his presentation is: "Why social networks are like carbon," and while Christakis is keeping quiet now the exact topic, saying "it's going to be a little bit of a secret;" but in a phone interview he made it clear that it'll be based on his current research.

Tuesday, April 6, 2010

Of Lightbulbs and Lasers

On April 24, the Cambridge Science Festival will open with a laser show. You'll be sitting in the dark, waiting for the show to start -- and then you'll think, "WAIT! How does that work?"

Let's start with a thought experiment...

Lasers and lightbulbs continue below the cut!

Monday, April 5, 2010

Hello Holography

Are you tired of your boring old two-dimensional photographs? Ever gone through your old family photo albums and wished that you could relive some moments? Don't despair; holograms are here!

Holograms are commonly described as "3D photographs," though the processes involved in making the two different types of photographs are quite different. Both conventional photographs and holograms are made on a flat piece of photographic film that reacts to different intensities of light, but holograms render information about the depth of the object: the object appears to literally pop out of the page. How do holograms manage to do that?

When you take a conventional photograph, your camera opens the shutter to let light through to hit the film. The light that enters your camera has already hit and reflected off the object that you're capturing. The object reflects light with different intensities (brightness) depending on the physical characteristics of the object. The chemicals on the film (usually a light-sensitive compound called silver halide) react with the light. How much the film reacts depends on how intense the light is. The regions that react more are darker in the resulting photograph. So, a photograph is merely a record of the intensity distribution of the object. However, it does not record any information about the phase of the light waves (see Figure 1), which we need if we want to know anything about the depth and dimensions of the object (a point that is further from the camera will have a phase different from the phase of a point closer to the camera).

Figure 1

How, then, do holographers capture—and then render—information about depth? They do it by making use of a standard or reference. This is similar to when you measure something with a ruler. You could just lay your ruler down on the surface that you're measuring and record a number, but that number is useless if you don't know what that number is relative to. You need to designate a specific point as zero (i.e. the reference). In holography, this reference is called the reference beam. The reference beam will combine with the light from the object, creating an interference pattern (see Figure 2). The film records the interference pattern. Since the intensity at any point in the interference pattern also depends on the phase of the light from the object, the hologram contains information about the phase as well as the intensity of the light waves.

An Ideal Polling Booth?

Have you ever thought about the design process behind a polling booth? If you haven’t, it’s completely understandable since most polling booths are not very sophisticated or aesthetically appealing. Then again, there’s only one requirement: to protect the privacy of the voter, and this can be done simply with curtains.

When I tried to find the history of the architectural design behind polling booths and how they’ve changed with the addition of new voting technology, I couldn’t find anything. Even with Google. I couldn’t even find anything about famous polling booths. The closest
site I could find to the history of polling booths discusses the mechanics behind how voting data has been collected (e.g. paper ballots, mechanical level machines, etc.)

The Internet cares more about the nearest polling booth than the actual design behind the booth. Then again, the designs aren’t usually memorable. Can you remember what the last booth you voted at looked like?

However, not all architects share this indifference to polling booth design. Joseph Choma, an MIT grad student, is schedule to present his design for the ideal polling booth on the second floor of the MIT Museum in the Emerging Technologies gallery from Saturday 4/24 to Sunday 5/2, and he will be available for discussion on Sunday 4/25.

Choma has posted an image of his first prototype polling booth design on his blog, architectuREdefined. His prototype clearly illustrates that polling booths do not need to be boring, challenging the banal nature of current options. His design is well thought out. As Eric Howeler noted, Choma’s design “acknowledges that the act of voting is a fiercely individual act, and the defensive structure serves to define a personal space/zone around the voter.”

This is one exhibit you just can't miss.

Sunday, April 4, 2010

Quantum Confusion

I’m going to let you in on a secret that I’ve learned as an undergraduate physicist at MIT.

No one understands quantum mechanics.

That seems odd, considering that most all of modern technology relies on it. Sure, physicists do the calculations (and do them spectacularly), but turning the crank on a machine doesn’t tell you why it does what it does. The problem is, science is really good at answering the question of “what happens,” but not so skilled at “why it does.” This leads physicists to uncomfortable situations when trying to tell people what in the blazes they’re talking about.

The mathematical foundations of quantum physics are rock solid; indeed they are the most statistically accurate theory we’ve ever created when it comes to testing predictions. The odd part is, the math involved is incredibly different then anything we had used before. A series of rules, called “axioms,” are followed. This is an idea descended from the Greeks, who realized that if you want to prove anything, you have to start from some basic unprovable assumptions (e.g., parallel lines will never touch).

It’s within these axioms that the weirdness of quantum physics hides. We can’t test why the weirdness exists, because we had to assume its existence to get anywhere.

For example, you may have heard of the famous example of “Schrödinger’s Cat.” Often told, this story is a way that physicists try to explain one particular weirdness about quantum mechanics. The story goes something like this:

“A mechanism is set up containing a radioactive material that could randomly decay at any moment, and when it does, a poisonous gas is released. If a cat is sealed in a box with this device and isolated from the outside world, quantum mechanics tells us that at a given moment, instead of a cat who is definitely alive or dead, we’d have a quantum cat who is alive and dead at the same time. Then, when the box is opened and observed there is a 50% chance of us seeing a dead or live cat.”

This is pretty confusing. The thing is, quantum mechanics really deals with insanely tiny object, like atoms or electrons. Connecting a tiny object (random decay of a radioactive material) to a large object (Schrödinger’s Cat) is a way of making us see how weird are the things quantum mechanics says go on inside tiny objects.

Fireflies - Your Backyard Beacons

While sitting on the porch of a dainty New England cottage, you spot a Lampyridae and notice its bioluminescent abdomen. In other words, you’ve sighted a firefly! You sit back and marvel at the simple beauty of its illuminated flight. Feeling more adventurous, you might attempt to capture the blinking beetles in a jar. Whatever your reaction, you have rediscovered the endless entertainment of fireflies. Why not experience this entertainment all day as scientists and bug lovers come together at the Boston Museum of Science for Firefly Day? This day-long event, taking place on Saturday April 24th, will feature all things firefly.

An entire day devoted to fireflies––sounds like a short day. After all, they are just beetles who fly around flashing at other beetles, right? Wrong! They are the capstone of natural selection, the product of evolutionary magnificence concentrated into one single blinking bug butt. These critters have evolved to flash signals, unassisted, at one another using firefly Morse Code.

Ever wonder how or why they flash? Fireflies are among a select group of organisms that produce light through a process called bioluminescence. This process involves the mixture of two chemicals found in animals (bio) which react to produce light (luminescence). That’s not so unusual. There are more popular light-producing chemical reactions, like burning wood. The molecular bonds in the wood store energy that is released during a fire. Similarly, energy stored in the molecular bonds of the bug’s chemicals are released during bioluminescence. Here’s the difference: when wood burns, it mixes with oxygen and uses heat to speed up the process. The “cool” thing about fireflies is that they don’t need heat. Their chemicals produce light without needing any external help. While the reaction in fireflies is a lot different than fire it is amusing to imagine each bug with a tiny campfire on its back. Unfortunately, as you’ve discovered, that’s not the case.

Now that you know how these blink at each other, are you curious as to why? Find out at Firefly Day at the Boston Museum of Science! Events from the 2009 Firefly day can be seen here.

In the meantime, want to attract more fireflies to your home? Here are a few tips from this website.

  1. Avoid the use of chemicals on your lawn if you want fireflies to make a home there. Would you want your living room smelling like Roundup?
  2. Turn off the lights outside. Fireflies rely on darkness to successfully send blinking signals.
  3. Provide your fireflies with a place to live during the day such as overhanging trees or tall grass. As an added bonus, this may also obstruct the view of nosy neighbors.

And remember, if you capture the fireflies in a jar, be sure to let them out quickly! Most of the blinking fireflies are males anyways. You wouldn’t want to leave too many males in a confined space for too long. It’s no wonder they all end up dead the next day.

To find out more about fireflies, check out these websites:

Friday, April 2, 2010

How Harvard women cut the keys to the Universe

“I’ll bet you that my HOUSEKEEPER can do a better job!”

This – or something like this – was apparently the line yelled at a male assistant by Edward Pickering, head of the Harvard Observatory, in 1877.

No one knows what blunder sparked the outburst, though we can bet that it was a whopper, given that women weren’t allowed even to operate a telescope at the time.

But we do know that Pickering made good on his bet – first hiring his housekeeper, and then many other women, to measure the brightness of stars – and that winning it would prove to be probably his greatest contribution to science.
Two of “Pickering’s harem” would devise entire new and efficient ways to classify the stars, while a third – Henrietta Leavitt - would do nothing less than revolutionize the way humans measured and understood their universe.
(Edwin Hubble would simply use Leavitt’s ideas and the world’s best telescope to make “the discovery of the century” in the 1920s – that our universe is filled with galaxies like our own, and is expanding.)
Still another woman, Cecilia Payne, would later come to Harvard to join the world’s most female-dominated science lab in the world, and discover for the first time what stars are really made of.

As a Harvard astronomy undergrad, I first heard the story of “Pickering’s women” in class, from one of their modern-day sisters: planet-hunting astrophysicist Dr Lisa Kaltenegger.
Wow, I thought.
Why wasn’t there a movie?

Of course, it was tough enough for women to get their hands on scientific instruments 100 years ago, far less the credit for their work. (Come to think of it, almost all the credit for Rosalind Franklin’s iconic discovery in biology – the crystalline structure of DNA – went to Watson and Crick just 50 years ago, so what’s new).

The Cambridge Science Festival will offer three sessions which celebrate women in cutting-edge science: “Inquiring Minds”, to be held from April 29 to May 1 at the Boston Museum of Science. The dozen speakers represent a remarkable diversity of scientific talent, from marine biology to chemistry and aerospace design.

But, for me, the thread of female scientific genius can be followed just as easily at any of the six astronomy-related events at the Festival, including “80 Years of Astronomy” (April 24), "From the Mysteries of the Brain to the Wonders of the Universe," (April 24) and “Cambridge Explores the Universe” (May 1).In fact, if they keep their eyes peeled, visitors to the latter – held at the Harvard Observatory – might find the names of two of the women I mention in this blog attached to two of the instruments they’ll get to play with (I ain’t sayin which).

“Cambridge Explores the Universe” is likely to be the most family- and fun-oriented of the astronomy events, with telescope tours, planetarium shows and even the chance to operate a robotic telescope at the MicroObservatory during the four hours of the open-house.

But there are some truly jaw-dropping story-lines behind the discoveries made at this place since 1839, and I’m particularly looking forward to the “Scientist Café” – where you’re invited to collar any of the working astronomers over a coffee and get them to give you an insider’s tale.

First, back to 1877: Asked to plot the brightness of stars onto photographic plates, here was the problem that Pickering’s blundering male assistant confronted: the brightness of the star on the photograph didn’t really tell you anything about it.
That’s because – unless it was a very nearby star, like Sirius - you had no idea of knowing how far it was from the earth.

Imagine being asked to measure all the lights from a photograph of an ocean scene on a moonless night.
The brightest one could be a 30 watt flashlight held in a life raft, 10 yards in front of the camera, and the dimmest could easily be a million candle-power lighthouse 3 miles away.

Using a combination of herculean patience and stunning insight, Leavitt discovered a pattern in a variety of star called "cepheids" which revealed their true power.
(Like a bell: the bigger the star, the slower its vibration cycle from bright to dim and back to bright.)
Although exploding stars are now used to measure the farthest distances, “Leavitt’s Law” – the relation between “period and luminosity” -remains the most accurate measuring tape in the universe.

But what about all the other stars? The ones that didn’t vibrate so reliably?
Again, “Pickering’s women” found the answer.
According to Debra Davis – editor of Woman Astronomers – his housekeeper, Williamina Stevens, and her unborn child had been abandoned by her husband just months after arriving in the US, and she was eager to find some means of financial independence.
Formerly a teacher in Scotland, Stevens proved so expert at plotting the brightness of stars on her boss’s photographic plates that she headed a project to survey the entire night sky (funded by another woman of central importance to astronomy: Anna Draper) and was appointed Harvard’s Curator of Astronomical Photographs.

Within 10 years, yet another female colleague, Annie Jump Cannon, invented an efficient new way to classify all stars at Stevens’ urging, and perhaps the most famous string of letters in all of science – “OBAFGKM”- to describe how they are organized.

As it turned out, nature would reward Cannon’s idea with an almost magical symmetry in the way that all “healthy” stars are arranged.
Incredibly, stars which are divided into groups of OBAFGKM (our Sun is a “G” star) by the fingerprint-like characteristics in their light, called “spectral lines”, can be arranged exactly the same way no matter if you’re dividing them by their size, their color, their total power output; their mass, their temperature, or even their life expectancy. (So all “O” stars will live shorter lives than all B stars, which will live shorter lives than A stars, etc. And O stars will also be bluer in color (And hotter. And bigger) than B stars, which will be bluer in color (And hotter. And bigger) than A stars, etc, etc.)

So that’s the distances and types of stars taken care of by Pickering’s pioneers.
But what about what they’re actually made of? (And most of the universe, for that matter)
Within three years of her arrival in Harvard from England – but working for Pickering’s successor - Cecilia Payne stunned the science world with an answer no one could challenge.
While her male counterparts had long insisted they were mostly made of iron, Payne proved it was hydrogen.
Other aspects of her research would form the foundation of the modern picture of how planets form, and how the elements are made.
And yet Payne was rated no higher than a “technical assistant” by her male director for 13 years after her groundbreaking discovery.
In the end, the pieces of knowledge we have about Harvard’s women astronomers are a lot like the faint points of starlight on their telescope plates: the blurred and often overlooked evidence of searing power.

I'd really welcome any comments or additional info folks might have about female astronomers.
Next week: I reveal how visitors will come face to face with a real, working time machine at the Festival.

Thanks for reading; cheers - Rowan

* (Rowan Philp is a Knight Science Journalism Fellow at MIT)

Thursday, April 1, 2010

The “Coolest” Way to Make Ice Cream

What is the secret to delicious and quick homemade ice cream? Liquid nitrogen.

Don’t believe me? Stop by the Cambridge Public Library between noon and 4pm on Saturday April 24--the Science Carnival is hosting an event called “Liquid Nitrogen Ice Cream Making!” where YOU not only get to witness the amazing spectacle of making liquid nitrogen ice cream, but also get to consume the delicious final product.

It’s a pretty cool looking process. Here’s a photo from the first time I made liquid nitrogen ice cream:

Nitrogen is readily found in our atmosphere, but only in its gaseous state (incidentally, nitrogen gas makes up 70% of our atmosphere). Liquid nitrogen, on the other hands, does not occur naturally on Earth. Liquid nitrogen only exists under super-cold conditions. I’m talking -321°F cold, way colder than any place on Earth. By comparison, room temperature is around 70°F, and the coldest recorded air temperature on Earth was “only” -129°F (that honor went to Russia in 1983).

If liquid nitrogen hits any temperature above -321°F, it boils immediately into nitrogen gas. That’s why the ice cream looks like it is steaming in the above picture. Liquid nitrogen “steams” into gaseous nitrogen as it boils, just like how water steams into water vapor when it boils. Same concept and same process, except liquid nitrogen boils at a much lower temperature, and thus its “steam” is correspondingly much cooler. Colder things are denser than warm things, so while steam from water rises, the “steam” from liquid nitrogen sinks. (You can see this in the photo and at the festival!)

Due to liquid nitrogen’s coldness, you must handle it carefully with proper equipment, like gloves and specialized cold storage containers, and such matters will be properly taken care of at the Science Carnival.

But why use liquid nitrogen for making ice cream? It’s not necessary to have liquid nitrogen to make ice cream, but it certainly makes the task much easier (provided that you don’t have trouble acquiring liquid nitrogen).

Making ice cream sans liquid nitrogen is a slow process, one where you must churn the ice cream a lot while it is being cooled. This is the usual approach of ice cream making machines you find at factories and in home kitchens. Why the churning? For texture! We love ice cream not only for its flavor but also for its texture. Churning ice cream while it cools prevents it from solidifying into solid blocks--after all, eating rock-hard ice cream would be no fun. Churning also whips the ice cream, aerating it to the fluffy and smooth consistency we love. Like any recipe that involves a lot of aeration (ever tried making whipped cream or meringues, for instance?), this takes a while, but liquid nitrogen turns ice cream making into a snap.

The secret lies in the extreme coldness of liquid nitrogen. Boiling at about 400°F below room temperature, the transformation of nitrogen from liquid to gas form is incredibly violent. Think about a pot of boiling water on a stove. If you turn up the temperature on the stove, the water boils more violently. Same concept applies for liquid nitrogen (just at much cooler temperatures), thus liquid nitrogen boils with extreme ferocity: it fizzles and sizzles and immediately turns into vapor, like water splashed onto a very hot pan. This intense bubbling action serves as a whipping and aerating mechanism. All you need to do is create an ice cream base (a combination of milk, cream, sugar, and flavorings) and pour liquid nitrogen into the base while stirring, cutting down on the amount of work you need to do churning. Moreover, all of the liquid nitrogen evaporates, leaving you only with delicious ice cream.

Without a doubt, the “coolest” way to make ice cream is with liquid nitrogen.