Could You Build a Scale Lego Model of the Death Star? ∞

According to Rhett Allain all you need is two trillion kilograms of lego. That weighs as much as 400 million elephants. Can you imagine trying to launch 400 million elephants into space? In low Earth orbit (~300 km), the scale model Death Star would appear bigger than the moon from earth:

People would mistake it for a moon, just like Han Solo did. Well, it look just like the moon except that it would just take a couple of minutes to pass across the sky where the moon doesn’t really seem to change its position.

Check out the figure that Rhett put together comparing the scale model to the World’s tallest buildings.

Why I Am Leaving Goldman Sachs ∞

Wow. Greg Smith submits his resignation letter to Goldman Sachs via the NY Times:

It makes me ill how callously people talk about ripping their clients off. Over the last 12 months I have seen five different managing directors refer to their own clients as “muppets,” sometimes over internal e-mail. Even after the S.E.C., Fabulous Fab, Abacus, God’s work, Carl Levin, Vampire Squids? No humility? I mean, come on. Integrity? It is eroding. I don’t know of any illegal behavior, but will people push the envelope and pitch lucrative and complicated products to clients even if they are not the simplest investments or the ones most directly aligned with the client’s goals? Absolutely. Every day, in fact.

The dark core of dark matter ∞

nasa abel dark matter 606x340 The dark core of dark matter

This composite image shows the distribution of dark matter (blue), galaxies, starlight from the galaxies (orange) and hot gas (green) in the core of the merging galaxy cluster Abell 520, formed from a violent collision of massive galaxy clusters. The image makes use of data from the Hubble Space Telescope, the Canada-France-Hawaii Telescope in Hawaii, and the NASA's Chandra X-ray Observatory. (NASA, ESA, CFHT, CXO, M. J. Jee (University of California, Davis), and A. Mahdavi (San Francisco State University, California))

The link above is an interview I did for CTV’s National Affairs on a new result that could change our understanding of dark matter.

Previous evidence points to dark matter not being able to interact with other dark (or regular) matter except weakly through gravity. Researchers at UBC took a look at a “cosmic train wreck” that occurred when two galatic superclusters smashed into one another. These galatic superclusters, each containing hundreds or even thousands of individual galaxies, are mostly made up of free Hydrogen gas. During the collision the gas interacts and gets “stuck” in the middle while the stars, planets, and dark matter should keep on moving through.

In this case it appears that the dark matter gets “stuck” in the middle as well, something that was not seen in previous observations of other cosmic train wrecks. There are a number of possible explanations, all of which will teach us something new about nature of dark matter:

  • Some dark matter may actually be able to interact with other dark matter via some new force.
  • There may have already been a large chunk of dark matter, without much regular matter, sitting in the middle where the collision took place. In this case, we need to understand how so much dark matter can exists without much regular matter.
  • Dark matter has a filament-like nature, similar to how roots on a tree grow. In this case, we may be looking at one of the filaments end on. Imagine looking at a pencil end on. All you would see is the pencil point and not have any idea how long the pencil actually is. A similar thing could be happening with the dark matter–what we see as a small dense core in the center could actually be a an incredibly long filament of dark matter.

This result provides another puzzle piece in the mystery of what dark matter is, how galaxies form, and what our place in the universe is.

A big thanks to Adrienne Erickcek and Keith Vanderlinde for walking me through this exciting work.

Project Q passes 300 participants

With a flurry of videos being submitted last night and today there are now 316 people who have taken part in Project Q! This is far beyond what I had hoped for. Thank you Lindy Hoppers for being so awesome. We have new videos from:

These videos are awesome. People have been doing some creative things. The crazy thing is that there are still more videos to come. Let’s see if we can hit 350 dancers!

Sheldon may play dice, but scientific publishing cannot be left to chance

This is a guest post written by a fellow physicist, Marco Piani, who loves quantum information and the TV show The Big Bang Theory

In a recent episode of the The Big Bang Theory, “The Wiggly Finger Catalyst”, Sheldon reverts to taking “minor” decisions by rolling dice. It does not always work perfectly, as Sheldon, for example, ends up eating food he doesn’t really want just because the dice have “decided” so.

Nonetheless, Sheldon argues that his mind, not burdened anymore by the consideration of minor issues, can focus better on questions much worthier of Sheldon’s attention. He judges his experiment a success, in particular because he is able to publish two papers in “notable peer-reviewed journals” in a short period. The measure of success adopted by Sheldon is actually shared to a good extent by the entire academic system: indeed, one of the main goals of a researcher is that of publishing papers in “good” journals. What does this mean? Sheldondice 606x404 Sheldon may play dice, but scientific publishing cannot be left to chance

A researcher devotes his/her work, for example, to better understand how the world works, to improve the treatment for some disease, or to create some new technology. These results only come with dedication and hard work. When there is enough progress—for example, when a group of astrophysicists have collected enough data about the explosion of a giant star, achieving a better understanding of the life cycle of stars—this progress is reported to the scientific community by means of an article published in a scientific journal—a highly specialized research magazine. Such an article may condense down to few pages years of work.

Roughly speaking, papers constitute the record of the progresses made in science (in all the senses mentioned above, and in many more!) and add to the body of human knowledge. Most importantly, they are used as references—that is, roughly speaking, as the starting point—for the future work of other scientists, as well as for developing applications of scientific knowledge.

It is then quite obvious that published results must be sound: that is, mathematically correct in the case of theory, and supported by the collected data—as well as by the methodology of the data analysis—in the case of experiments. A key issue is that science is divided in so many fields and subfields that only people working on the same or a similar topic can really check that the progresses being reported are, first of all, actually interesting progresses—worth being “archived” and developed in the future—and, most importantly, correct. Hence the notion of “peer-reviewed journals”: in order to publish, a researcher has to convince his/her own colleagues that what he/she has done is worth the attention of the scientific community and is correct. Furthermore, the level of “interest” of the results is nowadays often reflected by the journal in which the results are published: “good” journals have a higher bar for what is deemed “interesting”.

There are a lot of details and many subtle points that we are leaving out here. For example, the people who have to review a manuscript submitted for publications and to help decide about its acceptance—the “referees”—are often unknown, both to the authors of the manuscripts and to the rest of the community. The idea is that referees can then be less afraid to point out potential issues affecting the submitted paper, while they could restrain themselves from doing it if the persons whose work they are judging today could knowingly end up judging their work in the future.

The principle that whatever new result should be scrutinized by the community of peers is well established; in many ways it is a cornerstone of modern science. On the other hand, the exact process to arrive at the acceptance of new results and to their incorporation into the body of scientific knowledge—as well as the issue of how these results should be made available and disseminated—may change in the near future.

At the moment this process is mainly administered by scientific journals and their editors. It is the editors who receive the request from the authors to publish their manuscript. It is the editors who get in touch with potential referees, asking them to judge the submitted manuscript. It is the editors who, after reading the reviews of the referees, finally choose whether to accept the manuscript for publication. Most importantly, it is often the case that papers appearing in journals—that is, the only papers nowadays “officially” certified as “interesting and correct”—can only be accessed through the payment of a fee.

But exactly in these days many scientists and thinkers (notably Timothy Gowers, a Field medalist 1, and Michael Nielsen, the author of Reinventing discovery, an interesting book about how the Internet will dramatically change the way we do science) are considering how the traditional peer-review process and the scientific publishing industry could be disrupted by new online tools and by the more direct involvement of the community of scientists through these tools.

Sheldon may be happy about letting dice decide about other issues to focus entirely on finding new results, but researchers all around the world are aware that modern science is a very complex and collective enterprise. In particular, new results require both validation and dissemination; while “peer-review journals” have played and still play a primary role in these two processes, things could soon change.

  1. The Field medal is considered the correspondent of the Nobel prize for Mathematics ↩

Latest round of Project Q Submissions

We are up to 206 Lindy Hoppers who have taken part in Project Q! There have been a number of new cities who have submitted videos, and I know of a number of others who are either filming or working on their videos as the deadline approaches. I spent the past weekend working with the dancers, band, and other guests who will take part in the talk. It is going to be amazing. I cannot wait to show everyone the final product.

Eleven months at the bottom of the Earth

Last week I had the chance to sit down with cosmologist Keith Vanderlinde, a CIFAR Junior Fellow at McGill, who spent eleven months straight living at the South Pole in Antartica. During the winter temperatures dip below -70 C and their is continual darkness for nearly six months straight. It gets so cold during the winter that planes cannot fly in–once the last plane takes off you are stranded there until the following sumer.

While in Antartica, Keith was in charge of keeping the South Pole Telescope running. Every day he had to walk 1 km to and from the telescope, often in white blizzard conditions. Keith took his camera with him and captured a series of incredible photos of the night sky and life in Antartica.

While at the South Pole, Keith maintained a fascinating blog about what life is like. My favourite entry is about the 300 club:

There’s a tradition here at pole dating back decades, that whenever the temperature outside falls below -100F, the 300 club convenes & initiates new members. You gain entry into the club by first sitting in the sauna with the temperature turned up to 200F, then running outside (a 300F temperature differential, hence the name) and around the pole, all wearing nothing but boots and a smile.

Only once – in the half century for which we have records – has the temperature failed to hit -100F over the course of a winter. It’s expected that the 300 club convenes at least once each winter, more likely twice or three times. Well, with the sun now up and temperatures already rising into summer, our low for the year is sitting at -99.9F, and there’s no way that would count. Seriously.

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Project Q videos rolling in!

This past week there has been a flurry of activity with scenes around the world submitting their Project Q videos. So far 90 dancers from six cities have submitted videos!

I know there are several more cities shooting their videos this weekend. I’ll update the blog (and Project Q page) once the new submissions are online.

Here are some of the videos that have come in so far:

While I was in Vancouver last week I also filmed the local scene there performing the routine. I haven’t had a chance to post it online, but will do so later on this weekend.

A big thanks to everyone who has helped out so far. I really appreciate it.

The happy secret

Shawn Anchor shares some of the secrets to being happy. This talk contains almost everything I have come to believe about happiness.

A superb TED talk filled with humour and truth. Some excellent suggestions at the end for “creating lasting positive change”:

  • Find three things to be grateful for each day
  • Journal the positive things that happen
  • Exercise
  • Meditate
  • Perform random acts of kindness

Good advice.

HELP: What is your favourite science poem?

Next Wednesday I am giving a lecture to a first-year poetry class on the “Physics of Poetry”. In this talk I am going to discuss some of the connections between physics & poetry that I have encountered. I need some help though.

Specifically, I would like to find out three things:

  1. Some examples of poems that discuss Science? (ie When I heard the Learn’d Astronomer).
  2. Has poetry influenced the way you see the world?
  3. As a scientist, has poetry influenced your work or the way you share your work?

Any suggestions, thoughts, or comments people have would be greatly appreciated!

George and John’s Excellent Adventures in Quantum Entanglement ∞

A clever video by Scientific American about quantum entanglement and Bell’s Theorem. This is one of the better attempts that I have seen to explain the concept of hidden variables and the surprising nature of Bell’s inequalities.

I have thought long and hard about the best way to explain Bell’s inequalities. I would still prefer a less abstract approach, but I really like the way this video introduces the subject and I can’t think of anything better off the top of my head. Up to now I have used1 a different card trick to illustrate the surprising correlations that exist between entangled particles and not attempted to explain Bell’s work. Perhaps I can convince Marco and Robert to reprise their roles as Einstein and Bohr in a sequel.

Entanglement is such an awesome phenomena that has ramifications in philosophy, physics, cosmology, and biology. Sometimes I take for granted that I get to create entangled states of light in the lab every day.

  1. Technically it is Dan Trommater, my magician friend, who performed the card trick. ↩

The iPad revolution in education ∞

Fraser Speirs on Apple’s recent education announcements:

Apple already revolutionized education when it invented the iPad. While iBooks textbooks are a bridge from the past to the future—and we do need a way to get to the future—they are not that future. If Henry Ford had been an educational publisher, his customers would have asked for electronic textbooks instead of faster horses.

The recent announcement of digital textbooks, iBooks creator, and iTunes U is a move (mostly1) in the right direction. My feeling is that the best is yet to come. In some ways Apple’s development of the iPad is like Guttenberg’s invention of the printing press. All the benefits of the web, apps, and digital communication converge seamlessly in one device. The next ten years will be interesting.

  1. Except for the draconian licensing terms associated with iBooks creator. As John Gruber put it: “This is Apple at its worst”. ↩