Off the Hook Astronomy

Crochet, knitting, astronomy & life in general.

Friday, August 29, 2014

Gaia and the Cosmic Distance Ladder

I first heard about Gaia (Global Astrometric Interferometer for Astrophysics) during my undergraduate studies around 8 years ago. Although the impending space mission was hailed as one of the most important of the 21st century, it seems like it hasn't received nearly enough press in the last little while, which is why I wanted to talk about it in this blog post. The Gaia spacecraft was first proposed in 1993, on the coat tails of the Hipparcos mission, and was finally launched in December of 2013. And, as of a European Space Agency press release on July 29th, Gaia is now ready to do science!

Credit: "Gaia spacecraft". Via Wikipedia.

Gaia's motives range from discovering extra-solar planets to detecting quasars, but its most important purpose, in my opinion, is to precisely measure the distance to over 200 million stars within our galaxy to an accuracy of 10%, and out to a distance of 30,000 light years, well beyond the Milky Way's galactic centre. These distance measurements are obtained through a process called stellar parallax, where the apparent motion of a star is observed compared to more distant background stars as the Earth moves around the Sun.

Credit: "Stellarparallax2" by Original uploader was Booyabazooka at en.wikipedia - Originally from en.wikipedia; description page is/was here.. Licensed under Public domain via Wikimedia Commons.

Not only will the precise determination of the distance to this many stars in the Milky Way provide us with a detailed representation of the structure of our galaxy, but parallax is the most important fundamental measurement in the cosmic distance ladder. The cosmic distance ladder (or CDL) is a series of methods for determining distances in the cosmos which are calibrated to each other to greater and greater distances. The first rung in the CDL is the distances within our own solar system, which have been determined to great accuracy with radar. Once the Earth-Sun distance is determined precisely, accurate parallax measurements can be made.

The next rung on the CDL is a class of objects called a Standard Candles. These are objects which have a known brightness, and therefore, when their apparent brightness is observed, one can calculate how far they are (sort of like figuring out the distance of a car based on how bright its headlights look). A couple of famous examples of standard candles are Cepheid Variables and Type Ia Supernovae, which are used to calculate the distance to objects much further than can be achieved with parallax (such as with distant galaxies). However, in order to calibrate the intrinsic brightness of these objects, the distance to nearby standard candles must be computed via some fundamental measurement, such as parallax. Thus, having accurate parallax measurements for nearby objects allows astronomers to determine the distance to bodies which are much further away.

It becomes apparent, when the determination of distance to far-away objects must be calibrated in this way, that an error in a lower rung of the CDL can seriously affect the distance measurements to very faraway galaxies. This problem became clear in the early 20th-century when Edwin Hubble was making his first distance measurements to nearby galaxies. When he discovered that the Universe is expanding, he calculated the age of the Universe to be only about 2 billion years, which was a problem because the age of the Earth had been estimated to be at least 3 or 4 billion years! This was later resolved when the brightness of Cepheid Variables was properly calibrated, which more than doubled the calculated age of the Universe. We now know the age of the Universe to be 13.8 billion years, and the value is mostly obtained from the distance measurements of far-off galaxies.

In conclusion, accurate distance measurements to objects within our own galaxy can have implications for our understanding of the history of the Universe! Even though the primary purpose of Gaia is to map out the structure of our galaxy, it will have a great impact on our knowledge of cosmology.

Thursday, August 14, 2014

Bullet Journaling for a more productive life

Folks, so, so, so much has happened since I last wrote! First, the Relay for Life was a great success (you can read my buddy Erin's recap for a good summary). I also picked up a part-time job at a math tutoring centre called Mathnasium (I actually started end of February, but it's still news!), and then, mid-June, we found out about a really gorgeous house for rent that was actually within our price range. I'm talking back yard, in-suite laundry, central A/C… the whole nine yards! So, at the end of July, we moved! I promise to write a post about our new home, but perhaps when it's a little neater after we've unpacked a bit more.

So, here we are, in a new home for just about two weeks, still with what seems like a gazillion boxes left to unpack (though I have been making progress). I've felt like there's just so much to do that it sometimes gets overwhelming. This is why, at the beginning of August, I decided to start a Bullet Journal. You can read more about the process on the creator's website, but the basic idea is that you just write down things as they happen and distinguish between tasks, events, and notes with little bullets. I bought a cheap unlined notebook at the dollar store because I wasn't sure I'd enjoy the process, and I didn't want to waste a lot of money, but I'll probably go for a Moleskine or something similar for my next journal.

On the very first page, instead of making an index, I gave my contact information and wrote a little legend to keep track of the different bullets and signifiers. I put the index at the back of my journal instead of at the front so that if I ran out of space, I'd be able to continue on earlier pages. I've also seen some people use multiple indexes at random points in their journal. That could work too, I suppose, but it seems confusing. Here's my first page, decorated with colourful doodles on a slow day at work:

The next spread is my monthly calendar and tasks. On the left side, I made a list of all the days in the month, with the date and day of the week, and then started to fill in the more important events I already had planned. One small change I've made since I scanned these pages is I put a little event bullet to the left of each date so I can check them off as the days go by, which makes it a little easier to see where I am in the month. For my September spread, I'll definitely give my days a bit more room! On the left side, I started listing all of the tasks I could think of that I wanted to accomplish in August. I keep looking back on these and attempt to tackle one each day. The especially important and urgent tasks, I mark with an asterisk (for example, Daphne's sweater, which I need to finish before she leaves for England at the end of the month).

Then, we get into the meat of the journaling. Each day is a series of bullets. Tasks are demarcated by empty boxes, events are unfilled circles, and notes are filled in smaller circles. Every morning, I write down the things I want to get accomplished and the events for the day, adding more as I think of them. I check off tasks as I complete them and events as they happen. If, by the end of the day, there is a task left unaccomplished, I migrate it to the next day (with a little arrow) or cross it out if it became irrelevant. For the future, I think I'll probably only migrate tasks when I change pages, since they're still visible until I turn the page. As you can see, I've been pretty good at getting stuff done this way! It feels unnerving to still have little unchecked boxes at the end of the day, and just so good to add in that little checkmark when a task is complete.

Once I have enough tasks (or events or notes) that are similar in nature, I migrate them to collections, which I note in the index. The ones I show in the image below are for Blog Ideas and Crafting Projects. Some other collections I've added since are: Books to Read, Movies to See, and Songs to Learn on the Ukulele. I also added a collection for Future Dates. One minor issue with the Bullet Journal system is that it's difficult to plan for events further in the future than just the current month. So, as things come up, I just add them to the master list of future events, and when I start a new month, I'll migrate them there. Easy!

I've also personalized it a little with some Dalek post-its. I have a black one to indicate the current month, and a blue one to bookmark which page I'm currently on.

So that's my bullet journal! I've only been at it for two weeks, but so far, I think I'm enjoying it a lot. I'll admit to spending a lot of time fooling around on the internet, trying to find the perfect bullet journaling system, but overall, I think I'm getting more done this way. I'll certainly give a progress report once I've been at it for a bit longer.

Saturday, May 31, 2014

Relay for Life 2014: Knitting to help cure cancer

I'd like to interrupt our regular programming (haha…) to talk a bit about the Relay for Life. The Relay is a 12-hour overnight fundraising event for the Canadian Cancer Society. Teams come together at a park with a track, and one member of the team will walk the track for a while until another member of the team takes over. It is supposed to symbolize and honour a cancer patient's journey, ending with the hope of the sunrise.

I'll be participating this year with the Downtown Knit Collective team. All night, we'll be knitting charity items, and also providing the rest of the event with knitting, crochet, and other crafty lessons. In addition, we'll be selling small yarn-crafted items at the event… which reminds me, I'd better get on crocheting a few flower pins! Also, our team is currently in third place for fundraising!

And that brings me to the fundraising bit. I'm sure all of you reading this have been touched by cancer in some way. Myself, I've been lucky enough not to have lost anyone really close to me to the disease, but I have still known a few who have fought to survive it. More than one of my university profs has passed away after a fight with cancer, and just recently, my aunt had to go through a double mastectomy and chemotherapy when she was diagnosed with breast cancer. Even the smallest amount can help move us further towards a cure, so please consider pledging a small amount on my behalf. Donations of $10 or more are tax deductible.

You can donate by clicking here or by clicking on the image below. I'll be grateful for any donations, large or small! Thank you all in advance!

Wednesday, March 19, 2014

Ripples in Space-time from the Beginning of the Universe

The big news all over my Facebook feed (because obviously that's how I get news) Monday morning was all about what might possibly be one of the biggest discoveries about the Big Bang since the Cosmic Microwave Background (CMB), the faint glow of light left over from the Big Bang, was inadvertently discovered by Penzias and Wilson in 1964. The Southern Pole microwave telescope BICEP2, which stands for Background Imaging of Cosmic Extragalactic Polarization 2, measured a small signal in the CMB providing the first evidence for Cosmic Inflation.

Image Credit: BICEP2 Collaboration, NSF, Steffen Richter (Harvard)

Inflation was a theory first introduced by Alan Guth in 1980 that was designed to explain why the Universe appeared so uniform in all directions. Without Inflation, because widely-separated regions would have been moving away from each other faster than the speed of light, and so were not yet in causal contact, the Universe would not have had enough time to reach the temperature equilibrium we see evidence of in the CMB today. The solution was to have a period of rapid expansion in the first few fractions of a second after the Big Bang. Thus, a small region of space which was able to reach an equilibrium expanded extremely quickly to become an enormous volume that wasn't causally connected anymore, but that had achieved uniformity. The slight differences in temperature which we observe in the CMB would therefore have originated as quantum fluctuations magnified by the inflationary process.

Image Credit: BICEP2 Collaboration, NSF

Although Inflation solves the problem of the uniformity of the Universe, until recently it had no observational evidence to back it up. BICEP2 was able to provide this evidence in the form of tiny twisting fluctuations in the polarization of the CMB, that is, the preference of light to vibrate in one direction over the other, called B-Modes (see the top-right corner of the first image in this post). This polarization signal, which appear as faint spiral patterns on the CMB, is a result of ripples in space-time, called gravitational waves, created in the earliest moments of the Universe. Gravitational waves cause space itself to get squeezed and pulled apart very slightly, and this would manifest itself by twisting the polarization of the light coming from the Big Bang.

With an amazing discovery like this, it's tempting to make grand proclamations about how we now know how the Universe began, but unfortunately, we still don't understand the mechanism which caused Inflation. On top of this, only one team has made measurements of these B-Modes in the CMB, and it is wise to wait for confirmation from other experiments before getting too excited. One such experiment is called Spider, a balloon-borne experiment lead by Barth Netterfield at the University of Toronto in collaboration with teams from Caltech, Princeton, Stanford, and others. It was meant to fly this past December in Antarctica and make its own measurements of the CMB polarization, but because of issues at NASA, the experiment is delayed until next winter. Hopefully, it will then be able to confirm the results obtained by BICEP2.

Image Credit: Spider Collaboration, B.P. Crill et al.

You can learn more about this recent discovery by checking out these articles by the New York Times (with an excellent infographic about Inflation), Scientific American, and Space Ref, or by reading the original release from the BICEP2 team.

Friday, November 29, 2013

Things for weddings

It certainly must be said that at some point in your mid-to-late twenties, all of your friends will get married. This summer was certainly a testament to that (as was last summer) as I was invited to, and attended, four weddings. Fortunately, they were fairly spread out over the late summer and fall, so it wasn't overly overwhelming, and I've gotta say that each one was really a blast! And of course, because I am a crafter extraordinaire, for each one I had to come up with some sort of handmade component to each gift.

The first of the season was my cousin's. It was a gorgeous day in early August, the wedding was at a lovely golf resort in the countryside of Ontario, the ceremony was heartwarming, the reception was loads of fun (ohmygosh the food!), and I took no pictures because I forgot to bring my camera. I did, however, remember to take pictures of the absolutely adorable tea cozy which I made as a wedding gift.

I used the Fairy Cake Tea Cozy pattern by Frankie Brown, and used a scottish yarn (the blue) and some icelandic lopi (the beige and purple) which were both given me as a vacation souvenirs. (I think it's an excellent habit to get people to bring you back yarn from the exotic places they visit!) The pattern was super simple and fun to make, and those buttons are frickin' adorable. The tea cozy was given with that cute little yellow teapot inside, and I also included a sampling of fancy teas.

Two weeks later was my friend Nic's wedding. As it turns out three (THREE!) of the lovely ladies from my knitting group (we're famous on the internet) got married this season. Nic's was the first, and it was absolutely lovely. I, again of course, forgot to bring my camera, but I've stolen (totally without permission) this picture which Lynn's camera took of four of us in the tree house (TREE HOUSE!) at the wedding reception. I have in my hands what's left of the spoils from the ice cream bar (FRICKIN' ICE CREAM BAR!!!).

For Nic, I knit some wine bottle cozies to go with the LCBO gift card I gave her and her new hubby.

The pattern is Winecozy by Jennifer Carter and I used various soft and sparkly leftover bits of yarn. I'm an especially big fan of the adorable hearts on the black and purple one. The pattern itself is quite ingenious. I love the way the picked up tube thing makes the bottom quite stable. The only change I made was to knit in the round instead of flat.

Wedding #3 belonged to my knitting pal Erin. She had so much handmade goodness included in her special day! Probably most impressive (and not just because I helped), was the hand knit bridal and bridesmaids bouquets. All us knitter types in the group (and the token crocheter) helped a bit with that one, each of us making a couple of flowers. This picture is stolen from Erin's blog.

For her, I decided to try my hand at sewing and put together these napkins with nice folded edges and aluminum wire napkin rings:

The final wedding of the season was Lynn's in October. It was a Nerdstravaganza! And I mean that in the most flattering way possible. The programs were set up like a fantasy story and illustrated by the groom, each table had their own nerdy location (we were sitting at Aperture Labs), and they had custom-made LEGO figurines as party favours. Here's mine:

And our table:

And, for good measure, the happy couple:

I made an appropriately nerdy gift as well, a Doctor Who trivet!

It was made with some of my Mom's leftover lopi, and I used the chart from tricksyknitter called Whovian.

So that's it for weddings for a while, I hope!

Monday, November 4, 2013

Quinoa Salad with Cranberries and Red Pepper

Here's another recipe from the fitness blog.

Quinoa is awesome. It's full of fibre and protein and it's absolutely delicious. Bonus: it's also easier to cook than brown rice. A friend of mine turned me back on to quinoa recently. I'd had it before as a kid, but I hadn't eaten it since I moved away from home, mostly because I hadn't realized how easy it was to make. So I've been making all kinds of quinoa salads lately.

I used this this recipe as a jumping off point, and it is by far my favourite quinoa dish so far. It's kind of like a pilaf, I guess. I changed the original recipe enough that I think it merits a retyping here (keep in mind a lot of it is copied and pasted from the original).

Ingredients (main salad):
  • 1 c. dry quinoa
  • 2 tsp extra virgin olive oil
  • 2 cloves of garlic, minced
  • 1/2 c. dried cranberries
  • 2 cups water
  • 1/4 tsp salt
  • 1/4 red pepper, chopped
  • 4 c. baby spinach
  • 1/2 c. pumpkin seeds, toasted

Ingredients (dressing):
(NOTE: This wasn't actually included in the original recipe, but some kind soul put it in the comments. It turned out that I didn't have any yogurt or any of the spices at the time, so I made do with what was in the pantry. Experimentation is fun!)
  • 1/4 c. lemon juice
  • 1 1/2 tsp honey
  • 1/4 tsp turmeric
  • 1/4 tsp allspice
  • 1/4 tsp dried onion
  • 1/4 c. olive oil
  • 1/4 tsp salt
  • 1/4 tsp freshly ground pepper


1. Toast quinoa in a dry skillet over medium heat, stirring often, until it becomes aromatic and begins to crackle, about 5 minutes. Transfer to a fine sieve and rinse thoroughly.
2. Heat oil in a medium saucepan over medium heat. Add garlic and cook, stirring constantly, until golden, about 1 minute. Add cranberries and the quinoa; continue cooking, stirring often, until the quinoa has dried out and turned light golden, 3 to 4 minutes. Add water and salt; bring to a boil. Reduce heat to medium-low and simmer, uncovered, until the quinoa is tender and the liquid is absorbed, 15 to 18 minutes.
3. Meanwhile, toast the pumpkin seeds in a dry skillet at medium heat, stirring often, for 2 to 3 minutes. Put them in a bowl to cool.
4. Also meanwhile, make dressing by mixing all the dressing ingredients together in a small bowl. Transfer the quinoa to a medium bowl and toss with half the dressing. Add in the pepper and pumpkin seeds. Let cool for 10 minutes.
5. Just before serving, toss spinach with the remaining 1/3 cup dressing in a large bowl. Divide the spinach among 4 plates. Mound the quinoa salad on the spinach and eat!

This makes 4 servings. Per serving, there are 383 calories, 47 g of carbs, 19 g of fat, 8 g of protein, and 5 g of fibre.

Thursday, October 24, 2013

Yummy Tuna Patties

This is a recipe I originally posted in my fitness blog several months ago, but since not many people have access to it, I thought I'd republish it here! As some of you may know, I've been on a real health kick of late. I've lost about 50 lb in about a year and a half (most of which I had gained during grad school), I've started running long distances (I'm doing a 10k race this Sunday!), and in general I've been trying to improve my diet. Part of this has been to drastically increase the amount of protein I've been eating since I'm a real carb addict.

I find that the easiest way to get enough protein in my diet (not that I really get enough protein) is to have a can of tuna once in a while. I have been known to eat it straight out of the can when I'm feeling particularly lazy, but let's face it: tuna on its own is pretty damn boring. For a while I was mixing it with low fat greek yogurt (instead of mayonnaise), a few nuts, maybe some herbs or cut up veggies. I haven't bought greek yogurt in a while, however, so today I decided to mix it up with some stuff I had lying around the kitchen. Thus were born these super tasty tuna patties.

  • 1 can tuna (I used Gold Seal Chunk Light Tuna in broth)
  • 1 egg
  • 2 tbsp instant oats
  • 2 tbsp whole spelt flour
  • 1 tsp whole grain mustard
  • 2 tbsp fresh cilantro
  • small amount of fat for frying pan (I used a bit of non-stick cooking spray)

Mix everything in a bowl with a fork until it's well-blended. Heat up a frying pan to medium heat and add a small amount of fat for cooking (a couple of sprays of non-stick cooking spray in my case). Form the tuna mixture into patties with your hands and gently place them in the frying pan. I was able to make three approximately 3-inch patties. Cook for 5 minutes on each side. Serve immediately.

I've been told they keep, though I can't attest to that because I just wolf mine down right away. I topped them with a few tablespoons of cottage cheese, but low fat greek yogurt is also nice as would be a multitude of other toppings, I'm sure. Here's the nutritional breakdown for all three patties:

Calories: 277kcal
Carbs: 15g
Fat: 9g
Protein: 36g