Featured image: a 3D illustration of an enzyme. Since enzymes have a rich structure like the molecule in this image, they are tuned to perform specific reactions inside the body. (From Argonne National Laboratory).

This week, we invited Christin Monroe, a fifth-year graduate student in the Department of Chemistry at Princeton University, to come in and speak with us about enzyme production. Christin uses a variety of organisms, from E. coli to yeast, as factories for enzymes–3D molecules that perform specific chemical reactions, like hemoglobin carrying oxygen through your veins.

As a student in Professor Grove’s group, Christin first teaches a colony of bacteria to produce the enzyme in question. Basically, this involves getting a strand of DNA from an organism that produces an enzyme naturally, and stuffing this inside the creatures in a Petri dish (of course, it’s harder than it sounds!). Then, if the host understands its genetic instructions, it mass-produces the enzyme so that Christin can harvest it and purify it enough for further analysis.

That next step could involve all sorts of applications. Maybe the isolated enzyme is critical for a certain medicine to work in the human body, so its reactions with a particular drug are analyzed to minimize side effects. Or, the enzyme could digest some contaminants in our drinking water (as tested in Belgium), cleaning it for us and then decaying away. After all, enzymes are naturally biodegradable, so they perform much better and cleaner than the synthetic alternatives that chemists might produce inorganically.

Sometimes, the reaction between and enzyme and another chemical happens in stages, and these intermediate byproducts are crucial to understand. Maybe they cause unintended side-effects from drugs, or maybe they signify other chemical uses for the enzyme aside from the obvious. In any case, researchers need to look inside the quick reaction: so they might “freeze” the reactions to view these byproducts. Or, they might keep a careful eye on the reaction’s progress with diagnostics like spectroscopy, which watches the color of light emitted from a chemical to identify its changes in time.

Christin is more than a chemist–she has also organized several outreach programs here at Princeton. One of them, a series of lectures and career-services mentoring events throughout August 2016, is happening in partnership with the American Chemical Society, and will feature a public talk by Bassam Shakhashiri. Check it out: there’s more information on this page’s second story.

After the interview, Brian and Stevie moved on to the very serious topic of Arctic ice melting, which is so concrete that a cruise liner will be able to pass through the Arctic Ocean this August. This has never been possible for such a big ship before, so it goes toshow how quickly our ice caps are disintegrating (and allowing for morally questionable commercial ventures to jump in and take advantage of the new open seas). Afterwards, we discussed the not-so-serious naming of the new British Antarctic Survey ship, which will take on the name (thanks to the Internet) Boaty McBoatface.

Lastly, we ask a broad question: should science be done for application’s sake, or for nothing but curiosity? Most science questions originate when a researcher finds something interesting and wants to find out more, but generally they get funded when the researcher connects the question to an application in engineering that might benefit society. But research for its own sake can produce spin-off technologies that were never expected, and also provides the chance for revolutionary results instead of incremental progress. Plus, humans are curious: shouldn’t we satisfy the urge to know more, especially if it leads to scientific truths unbiased by the economic forces around us?

As always, you can find the playlist for the show on WPRB.com, or below.

 

Image: Casimir plates, which attract each other just because of standing waves that exist in vacuum between them. Just one of many crazy effects predicted with math!

This week on These Vibes, we hosted Justin Ripley, a second-year graduate student in the Princeton Department of Physics, for an interview about his work in theoretical cosmology. The discussion dug into the deep philosophical side of physics, probing ideas like how time began and what clumps of dark matter might look like.

Justin is a cosmologist, which means he studies events that occur on the grandest scales of our universe. He’s driven by a search for fundamental laws: what did the universe look like when it was the size of a basketball? What can those processes tell us about the rules underlying our present-day reality? When you look at space around us through this lens, the stars and planets become fossils–and cosmology is excavating these remains of the Big Bang for deep clues about the nature of physics.

One notion Justin brought up is the idea of anti-gravity. Unlike the attractive force that keeps us on Earth and our solar system in alignment, this repulsive force can happen when you consider negative energy states, an idea which is hard to visualize in practice but which can be expressed in mathematical models. It’s examining these equations that Justin hopes can lead to new developments in cosmology. If the models line up with experimental evidence (like Stevie’s cosmic microwave background, or LIGO’s recently-discovered gravity waves), then we can push the laws of physics into new territory.

After many questions from listeners, we moved on to dark matter and the ways in which it might clump together. Like we discussed last week, dark matter has to exist, because we can indirectly measure its mass–but it’s invisible and doesn’t interact with anything (except gravitationally). Scientists like Lisa Randall at Harvard point out that dark matter could form planets and galaxies of its own, clumping together (check out the N-body simulation below!) just like the matter that makes us and our Earth. Experiments like Gaia are examining the motion of astral bodies, trying to detect changes in their paths that might indicate clumps of dark matter nearby.

After Justin’s interview, Stevie came on the mic to talk about this exciting new study that might allow universal organ transplants. Just as some peoples’ blood types aren’t compatible with others, organ donations tend to be limited by the need to find a perfect match. That’s why family members might be the first to give up a kidney for their relative: because their genes match so well, there’s a better chance the donated organ won’t be rejected by the recipient’s immune system. This new technique, called desensitization, could allow even an incompatible organ to remain successfully in its new body after the transplant. Even though the technique is new and (presently) expensive, it’s worked in many patients and has the potential to revolutionize the way we organize transplants.

To end the show, Justin and Brian talked about Google’s AlphaGo computer and its 4-1 win against Go grandmaster Lee Sedol over the past week. This is a historic win for artificial intelligence, since Go is known to require a lot of intuition: it’s a game that humans are good at and computers have a hard time learning. DeepMind’s team overcame this obstacle with neural networking (as discussed in this past interview), which allowed the computer to learn the game and tune its strategies over time.

The playlist can be found here on WPRB.com.

 

Featured image of Pluto, taken by New Horizons during its flyby of the dwarf planet. Courtesy NASA, which has a spectacular gallery of other images too.

This week on These Vibes Are Too Cosmic, we interview Aida Behmard, a post-baccalaureate scholar at Princeton, whose research involves finding exoplanets and postulating about the types of extremophile alien life that might live there.

Aida has been digging through a trove of data from the HATNet project, a series of ground-based telescopes pointed up at swaths of the sky to try and find stars with planets orbiting around them. She searches through the history of telescope measurements, trying to find the moment when a planet orbits right in front of a star. When the star’s brightness decreases incrementally, the researchers can tell that a planet has blocked some starlight and thus can learn about the eclipsing planet. And it works–so far, the project has discovered 56 exoplanets around distant stars!

Motivated by the origins of life, Aida hopes to learn about the atmospheres of these new exoplanets and thus narrow down what kind of life might live there. These extremophile organisms, maybe used to harsh atmospheres and even radiation, could exist in many different forms surprisingly different from the kind of life we’re used to on Earth. To understand the possibilities, Aida communicates with biologists about what living structures might exist so far away.

We talked a bit about the wild astrophysical spirals that can exist around the centers of galaxies, active galactic nuclei. These insane structures have materials spinning inward into massive black holes, which produces violent amounts of radiation all over the spectrum–from radio waves to X-rays and beyond. Since these signals are so widespread (even including visible light, like the NASA image shown), it’s easy to see light from galactic nuclei all over the sky, through all kinds of telescopes that we use to observe outer space.

Finally, Aida is the director of a new outreach project at Princeton, Open Labs. This program organizes science talks aimed at different grade levels, and it brings in classes from local schools to hear about all kinds of research going on at Princeton. Check it out!

After Aida left, we went on to talk about the new observations of Pluto by NASA’s New Horizons mission. The new knowledge we have about Pluto’s geography is stunning, and will keep planetary geophysicists busy for years to come. The surface of the dwarf planet is mostly made of 40 Kelvin (supercold!) nitrogen and water, which are both solids at this temperature. Their consistency is different, though: the nitrogen ice is soft, like quicksand, and the water is rock-hard. Thus, Pluto has frozen features like Sputnik Planum, shown to the right. It’s a massive nitrogen sea, with glaciers and mountains of rock-ice floating around it and inside it. Still, there’s tons more to learn about Pluto, since the low-bandwidth connection we have with New Horizons means it will be months more before we harvest all its wonderful images.

To end the show, Stevie talked all about SIGSALY, a system of cryptography used in World War II that kept messages secret with vinyl records. These massive stations would be set up at important military bases around the world, and then two matching records (one message, one decoder) had to be played in unison for a highly-secret message to be understood. This technique, which involved briefcases of decoder records and 55 tons of high-tech processing equipment per station, paved the way for modern cryptographic techniques and data processing (that allows us to communicate in war and for you to use your cell phone).  Learn all about it here!

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