Wednesday, November 30, 2011

The Physicist Parent

I've chatted with colleagues at work a number of time on their kids and schools. Often, this revolves around what they see of the math and science (particularly physics) education that their kids get from their schools. Obviously, being physicists, they certainly do know quite a bit more than the average parent about the math and physics subject matter that the kids are learning. My colleagues at work certainly pay close attention to making sure their kids are doing their school work, etc., but some time, they also notice "strange" or not-quite-correct material that the kids are learning. Most of the time, it is more of the education approach that the students are put through that they found a bit odd, but there were times where they had to correct a few misleading or incorrect idea that they had come across.

So what about you? Are you a parent of a child or children that are in school and learning math and science/physics? Do you monitor closely what your kids are learning, and have you found a few things that you had to correct? Do the teachers of your kids know who you are and what you do for a living?


Tuesday, November 29, 2011

"Crowd-Sourcing" Teaching Philosophy

A while back, oh let's say from some time in 2006, I mentioned that Nobel Laureate Carl Wieman had accepted a position at the University of British Columbia. The interview the article I cited gave reasons for his departure from Colorado.

This news article catches up on what has transpired since then, including his initiative in revamping how physics is taught in college. From the results cited so far, it seems to be working. But there's a long way to go to not only implement such a thing, but to convince everywhere that it is the most effective means to teach.


Saturday, November 26, 2011

The Physics of Parade Balloons

Many of us here in the US celebrated our yearly Thanksgiving Holidays this past Thursday. One of the yearly traditions on this holiday is the Macy's Thanksgiving Parade in New York City. One of the most popular parts of the parade are the giant balloons consisting of different characters and items.

So here is a short article and a video on the physics involved with these giant balloons, in case you're interested.


Tuesday, November 22, 2011

The Explicit Siphon

I'm not sure what "explicit" means in the title, but that's what we have in this latest paper by Binder and Richert published in Physics Education. This is a follow up to an earlier article that I mentioned a while back that tries to correct a correction on the physics of a siphon. It certainly turns out that a common phenomenon such a siphon can stir up (no pun intended) such lengthy discussion, which isn't that unusual in physics. In fact, some of the most fascinating discussions that I've had were on such "mundane" physics.


Can The LHC Test For Superluminal Neutrinos?

That seems to be the case in a new paper that is about to be published. A new theoretical model by Davoudiasl and Rizzo based on the earlier one by Cohen and Glashow indicates that the LHC itself, using their existing detectors (probably ATLAS and CMS) might be able to detect signatures of superluminal neutrinos, if they exist.

Now, Hooman Davoudiasl of the Brookhaven National Laboratory in New York and Thomas Rizzo of SLAC National Laboratory in California have re-examined Glashow and Cohen's theory. True, the framework would open up neutrino decay in a vacuum, Davoudiasl and Rizzo say, but the OPERA neutrinos were travelling mostly through rock. Perhaps the rock stalls the decay for some reason – for example by making the neutrinos transform or "oscillate" into different types – which would mean Glashow and Cohen's theoretical framework would still be compatible with the OPERA result.

If so, then Glashow and Cohen's mechanism should turn up in other places – notably at the LHC, say Davoudiasl and Rizzo. Neutrinos are produced in the particle accelerator, for example when energetic top quarks decay, but they are not normally observed because they pass straight through the detectors. But if Glashow and Cohen's mechanism is at work, then some of the neutrinos should themselves decay, at roughly a metre from where they are produced. To someone studying the particle trails, this decay should manifest as an energetic electron–positron pair appearing suddenly, as if from nowhere. "This is a relatively easy signal to spot at the LHC," says Rizzo.
Easy? :)

In any case, I don't think this might be a convincing "evidence", whether such signals are detected or not. As stated in the article, the only convincing way to confirm or refute the OPERA results is for other long-baseline experiments, such as MINOS and T2K, to do the experiments. Until then, we will continue to go back and forth with model-dependent mechanism that will not be as convincing.


Liquid Nitrogen Show

This is a fun video of a liquid nitrogen demonstration to the public during the 2010 Jefferson Lab Open House.

Unfortunately, how many National Labs can do these Open Houses again? With the austerity measures being in place, and with the budget constraints, cutbacks, and uncertainty, such spending to educate the public and familiarize themselves with the National labs are gone. Open Houses at these labs are "luxuries" that they can no longer afford to do. And that's sad, because it is during such times that the public needs to know the important functions that these labs do, and why they deserve public support.


LIFE's Best Ever Science Photos

LIFE Magazine (anyone still remembers that?) has compiled what it calls its 37 best ever science photos. Many of them are certainly amazing and historical, such as the snapshot of Einstein's empty office on the day he died. It's a nice way to spend a few minutes just looking at pictures.



Monday, November 21, 2011

Searching For Supersymmetry At The LHC

We already know that the LHC still hasn't found any evidence for Supersymmetry. This report gives an overview of the search, and highlights the latest paper published in PRL from the CMS collaboration on their search for Supersymmetry. It also contains a free link to the paper in question.


Search for the Higgs Nearing an End?

There isn't that many places left for the Higgs boson to hide, if it exists. The latest result has ruled out large chunks in the range of energy where the Higgs could be. What is left now is the 114-141 GeV energy window, which is very small.

Nature has a short video interviewing the various people on the continuing search, and the possibility that there might be no Higgs.


Friday, November 18, 2011

OPERA Still Sees Superluminal Neutrinos

Well, they did a check, and they continue to insist that they see these superluminal neutrinos.

The new tests, completed 6 November, did away with the statistical analysis by splitting each pulse into bunches just 1- to 2-nanoseconds long, allowing each neutrino detected at Gran Sasso to be tied to a particular bunch produced at CERN. These tests were carried out over 10 days and provided 20 events. The researchers confirmed that the neutrinos arrived 60 nanoseconds early, with an uncertainty of about 10 nanoseconds, comparable to that of the initial result.
What they had done is to see if the bunch length could be the source of the error. I think most people that I talked to think it is more of a timing/analysis error, which they haven't really looked into yet.

You may read the updated preprint of the OPERA paper here, which includes this latest short-bunch test.

A major concern among the dissenters is the fact that the "time window" within which neutrinos were detected by OPERA in the most recent run had a width of 50 nanoseconds, something that the leader of the superluminal analysis, Dario Autiero, only revealed once the tests had been carried out. It was initially assumed that this window was just 10 nanoseconds wide. This difference does not affect the final result itself, the source notes, but dissenters say it highlights poor experimental procedure. Some researchers are also unhappy that only a small fraction of the analysis, which was carried out by Autiero, has been independently checked by others within the collaboration. This leaves open the possibility, they say, that not all possible errors have been accounted for.
It will be interesting to see what happens during the referring process. I can certainly see this being published, but with a result this important and this controversial, the only way it will ever be accepted is if T2K and MINOS verify the result. It is as simple as that.


Wednesday, November 16, 2011

Fermilab's "Physics For Everyone"

If you are around the area, there is no excuse to not make some time to attend one of these. The Fermilab's series of physics talks for the public is back.

So even when the Tevatron is gone, the lab isn't dead. But more importantly, they are continuing their effort on public education. This is the opportunity not only to listen to some of the best people around talking on a particular topic, but also to interact with scientists working there.

At least this isn't a dance performance depicting, say, Project X! :)


Tuesday, November 15, 2011

LHCb Sees CP Violation in D Charm Mesons

Forget the Higgs. The LHC has plenty of other physics to tackle.

New report out of the LHCb detector shows an asymmetry in the decay of the D and anti-D charm mesons that signify a CP violation. The CP violation events are thought to be a major candidate in explaining why our universe is populated by matter and not antimatter. We have already seen examples of such violations in Kaon decay. This observation, if it holds, is a stronger-than-expected detection in the charm meson.

You can read a more technical description of this at Cosmic Variance.

Plenty of exciting stuff ahead for the LHC, even without the Higgs.


Monday, November 14, 2011

What Is Antimatter?

You might learn something from watching this video.... at least, on the superficial level. :)


Cheating In UCSD Physics Lab Classes

Honestly, is this that surprising?

A group of researches discovered "widespread" cheating in undergraduate physics lab classes at the University of California-San Diego.

The study also says, "Overall, a large percentage of students perceive more cheating than they admit to. For example, while only about 11 percent of students admit to sometimes or frequently receiving unpermitted help, almost 66 percent perceive that other students are doing this."

In a survey, more than 65 percent of the students said that other students fabricated or falsified data in physics lab.

The researchers add that, "Perhaps the most disturbing finding of our study is the sheer number of students who perceive that teaching assistants ignore the copying that occurs. This is despite the fact that the teaching assistants receive extensive training on lab management, teaching laboratory concepts, and enhancing academic integrity in the lab. As a result of this training, we would hope that close to zero students would perceive a lack of integrity by the teaching assistants."
First of all, this issue of cheating is nothing new. I've reported news of such things already, and I will bet that this is not confined to just physics. The issue with being a TA faced with such a problem is also something that I've written a while back. It isn't easy, and it does require a lot of work.

I still say that one of the major problem is that students are given cookie-cutter laboratory exercises. There isn't an element of "here, investigate this on your own, and device your own way to do it"-type of exercise. When I proposed a revamping of undergraduate physics labs, one of the possible outcome is that there will no longer be a highly-structured laboratory work, and that in many of these, the students have to come up with their own way to tackle the problem. Till these laboratories have some variations to them from one year to the next, you will continue to have students who will try to get away with as much as they can without doing what they are supposed to.


Saturday, November 12, 2011

The Confluence of Physics And Dance

Ah yes, one of my favorite topics to ridicule! :)

Let's be honest here, I am NOT a fan of such "interpretive" dance that proclaim to somehow able to interpret some aspect of physics. When one understands a physics concept only superficially, and then one tries to demonstrate this visually, the result is often either hilarious, or downright puzzling. I've already criticized such attempts in previous blog entries (read here, here, here, and here). So there's nothing that I will say in this one that I haven't said before.

But still, it is worth repeating how ridiculous this all sounds. A dance titled "The Matter of Origins" has been performed as part of the Chicago Humanities Festival. Wait till you hear what this dance is all about. It's the doozy!

"Matter of Origins" explores that moral paradox, along with a technical one involving the nature of physical matter. If reality consists of tiny particles, how is it we don't fall through objects containing millions of gaps--a question raised by a contemporary physicist and his wife lying in bed in a scene projected on the work's giant curved screens, where images of the galaxy and the particle collider in Europe are also telecast.

Much of the dancing explores affinities between art and physics. A group approaches the front of the stage, the line of dancers moving their outstretched limbs together in a way that evokes the long debate about light--is it particles or waves? One sequence involves a woman and three men who keep moving a chair away from her--a blunt but keen illustration of the Uncertainty Principle.
Now people, c'mon! I dare you to either read that, or sit through something like that with a straight face! This is really some seriously funny crap here! That thing with the chair to illustrate the HUP. That is too hysterical! You can't make this up!

It is too bad that we can't introduce science, and physics in particular, directly to the people without having to go through such "interpretation". One can only wonder what the average public actually learn from viewing something like this. I hate to think that the HUP is now being depicted as a really bad game of musical chair!


Friday, November 11, 2011

Reporter Toured Accelerator Physics Facility, Thought It was "Particle Physics"

I've mentioned before when people confuses "accelerator physics" with particle physics, thinking that these two are synonymous with each other. They are not. Yet, these misindentification continues to dodge the field of accelerator physics.

This reporter got a tour of Jefferson Lab's accelerator complex that produces free electron lasers. FELs are in the domain of accelerator physics, because it is a study of beam dynamics, accelerating structures, insertion devices such as undulators/wigglers, etc.. etc. It has nothing to do with "particle physics", which is the domain of high energy physics/elementary particle physics. Yet, he is giving credit to it being about "particle physics".

I learned that research of ultraviolet and infrared lasers being conducted at Jefferson Lab could have numerous real-world implications, from medical research to producing hockey puck-sized miniature satellites. The satellites would have turbines the size of a penny.

The tour was fascinating, but I have to admit, when I got home, I had a "particle physics" headache that required two aspirin for treatment.
The funny thing here is that JLab is not even considered as a "high energy physics" laboratory, which is what is usually associated with "particle physics". It CEBAF is considered to be a "nuclear physics" facility, very much like RHIC at Brookhaven. Sure, they do particle collision, but these facilities are funded out of DOE Nuclear Physics division, not High Energy Physics, and are not considered as a "particle physics" laboratory the way Fermilab and SLAC were. So even neglecting the fact that this person was touring an accelerator physics facility in the first place, even JLab in general is not technically a "particle physics" lab.

Or maybe I'm just being too anal-retentive....but I'm still accurate! :)


Thursday, November 10, 2011

Physics Apps

So, what physics or physics-related apps do you have installed on your smartphones or tablets? Angry Birds does not count! :)

I think there's a tendency to try all those "physics equations" or calculator and stuff, but in my case, I don't find that to be that useful. So all in all, I only have two apps that I would consider to be related. One is more of a "useful" type that I can look up whenever I need to, while the other is more of an "amusement" type.

First of all, I have an Android phone. I would like to have an iPhone, but that's another story entirely. But so far, my Samsung Galaxy S II is working just fine, and it is slowly weening me off from wanting an iPhone. So all of my apps are obviously those available on the Android platform.

The apps that I consider to be useful is a periodic table app called Periodic Droid. I need this because, as someone who deals with materials issue often as part of my job, it is nice to be able to look up properties of elements on the spot, especially in a meeting. I tend to not carry my laptop with me all the time, so having access to a periodic table and search some of the basic properties is usually useful. The Periodic Droid is a free app, which means it comes with advertisement, but you can send in a donation and it will give you a code to change it to a no-ad app.

The apps gives a list of standard info for each element, such as: symbol, atomic number element category (metals, semi-metals, etc.), atomic weight, the phase state at 0 C, boiling point, melting point, electronegativity, crystal structure, period, group, electron affinity (in kJ/mol, but it would have been nice to have it directly in eV), valence number, first ionization potential (in kJ and eV, now that's more like it), atomic radius, covalent radius, ionic radius, sheer modulus, density, thermal conductivity, specific heat, heat of fusion, heat of vaporization, heat atomization (?), atomic volume, year discovered, abundance in sea water (?), abundance in Earth's crust, color, electron configuration, oxidation states, source, toxic or not, carcinogen or not, use (?), number of neutrons, electrons per shell, half-life, lifetime, name of discover/s, name of "first isolator", and monoistopic mass. Phew!!

I certainly don't need all of that, but knowing the electron configuration, crystal structure, electron affinity, first ionization, and conductivity are all useful at one time or another. So these are nice to have at my fingertips, or at least, close by.

The other app that I have is more of an amusement. It is Google Sky, and it is free. Google Sky lets you use your device to look at the known stars and constellations. You hold it up in any direction, and the screen will display all the known stars and constellations that are directly behind it in the sky! It is a very cool app! It will even show if one of our solar system planets is in that view. I've used it to identify a bright dot in the sky that I observed with my naked eye, and it happened to be Saturn. And guess what? I don't think there's an equivalent app for iOS. There certainly isn't a Google Sky app for that platform, since someone did try to look for it.

I've browsed the Android Market looking at other physics/math-related apps, and so far nothing else has caught my eye. So, do you have such an app that you would like to recommend?


Steve Koonin To Leave DOE

The US Dept. of Energy has announced that Steve Koonin will leave his post as Undersecretary for Science at the DOE.

Koonin's departure, announced in an 8 November memo from Secretary of Energy Steven Chu, busts up something of a scientific dream team within the upper echelons of DOE. Its other members are Chu, a Nobel Prize-winning physicist, and William Brinkman, the director of DOE's Office of Science, who was executive director of physics research at the storied Bell Labs. However, observers say they're not surprised to see Koonin go, as his position gave him little power.

"Steve's been looking around for awhile—it hasn't been a secret," says Michael Lubell, a lobbyist with the American Physical Society (APS) in Washington, D.C. "He has not been terribly happy at DOE for some time."

You may read the possibler reasons for his departure in the article. At first I thought this was one of the fallout from the Solyndra debacle. Luckily, it wasn't!


Wednesday, November 09, 2011

The Most Useful Major?

Oh, you have got to read this article. This was a "debate" held at Notre Dame University.

A diverse group of Notre Dame professors gathered Tuesday to defend their respective majors as the most useful tool to rebuild society if the world ended today.
Now, that sounds a lot of fun, doesn't it? :)

Since we're concerned about physics, let's see what the physics representative had to say:

Michael Hildreth, associate professor of physics, argued the merits of his field and said physics helps mankind at the most basic level, such as producing flame. Hildreth lit a piece of paper on fire in the debate to illustrate his point.

In addition, he said technology allows civilization to grow and thrive, and increasing technological progress has accelerated due to discoveries in the physics realm.

Hildreth said physics contributed to the development of the transistor that enabled the creation of computer chips, like those found in the iPhone.
I'm certain there's a lot more to this than what has been reported. For example, here's the one for theology:

Associate professor Gabriel Reynolds, a faculty member in the Department of Theology, grounded his argument for theology on a letter he found earlier in his office.

"What if every single person is precious to God?" he said, citing the letter. "Wouldn't it be cool if people discovered this God who cared so much that he cried for them? Wouldn't it be hopeful having this knowledge?

"I'm going to pursue the study of the real light of the world."
So guess which major the students voted as the most USEFUL? (Remember that word).  They voted for THEOLOGY!

I know!

Really? Useful? To do what? Feed your soul? Let's see how long you can stay alive by simply feeding your soul!

Regardless of the merit that each of the majors have, at some point, one also needs to wonder on whether these types of debates are dependent not only on the points being made, but also the STYLE and presentation. Would a more persuasive, charismatic person delivering the SAME message influence how people would vote? Sure it would! I've already mentioned many times that one needs to be shallow, perky, and superficial when conveying science to the public. The message itself can be empty. It is HOW you deliver it that is important. All bells and whistles. Or as Billy Flynt would say, "razzle dazzle them".

Theology more useful than physics and chemistry? Give me a break!


Tuesday, November 08, 2011

Value of College Education, and Employment Rate and College Majors

I ended up spending way too much time reading these stuff, but this is rather interesting, especially if you're interested in college education and employment.

First of all, I came across this news article from the Wall Street Journal. It listed the employment rate for many different college majors in the US. There are several fields where the employment rate is 100%! Of course, it doesn't state if all those people who majored in that field are also employed in the same field. But hey, nowadays, a job is a job.

In reading this, I decided to find the source of the study, which came from Georgetown University Center on Education and the Workforce. I found the report, which you can read in full at this link.However, in search for this one, I also came across another report on the value of a college education here in the US, especially in terms of a "lifetime" income. That is another good reading as well, with tons of statistics. And then, there's a report on employment, income of STEM (Science, Technology, Engineering, and Mathematics) majors. It is interesting to note that someone with an "lower" degree in a STEM field can earn, on average, higher than someone with a higher non-STEM degree.

Lots of stuff in here, and will keep you busy for quite a while!


Freezing Egg In Liquid Nitrogen

More fun video from those folks at Jlab! This time, based on someone's suggestion, they froze an egg.

Unfortunately, there aren't a lot of physics discussion in the video itself. If you go to the YouTube site for this video, you get a bit more of some of the physics surrounding this demonstration in the discussion and comments. The one thing they asked was why it took 8 minutes to freeze the egg, but it took 2 hours to thaw it, even when the temperature change is the same. This is a good question to ask the kids! :)


Monday, November 07, 2011

The Kilogram To Be Tied to Planck Constant

I've mentioned before of the issue related to the last of the 7 SI units that still is not tied to a fundamental constant - the kilogram. This is compounded by the fact that one of the standard mass that is being kept outside of Paris is changing mass. They think it is losing weight, but they're not sure now if it is a weight loss or a weight gain (really?!).

Still, at the end of the article in that last link, there was something that I didn't know about.

Mr Picard said the kilogram had gained (or lost) the equivalent of a small grain of sand in weight, but that was enough to throw out calculations in everything from precision engineering to trade.

It will be replaced by the Planck Constant, named after Max Planck, which is the smallest packet of energy (or quanta) that two particles can exchange.

Last month the General Conference on Weights and Measures (CGPM) agreed to use the constant to calculate the value of the kilo - but not before 2014.
Whoa! I didn't know they decided on that already! So I went and did a search, and found it immediately. This is a press release from BIPM.

A redefinition of the kilogram first requires highly accurate measurements of a fundamental constant of nature in terms of the mass of the international prototype of the kilogram, currently exactly equal to 1 kilogram. The numerical value of the fundamental constant will then be fixed and the same experiment will later be used to measure the mass of objects including the international prototype. Several facilities throughout the world capable of carrying out such measurements will be needed after the redefinition in order to make practical use of the new kilogram definition.

The target uncertainty for the most accurate of such measurements is 20 microgram per kilogram, which is the same as 20 parts in one thousand million. It is remarkable that at least two experimental approaches are very close to achieving this goal. One approach uses a special electronic balance – a “watt balance” – in order to measure the kilogram in terms of the Planck constant, which is the fundamental constant of quantum mechanics. A second technique compares one kilogram to the mass of a single atom of the chemical element silicon. Physics tells us that the results of these two seemingly different approaches can be accurately compared with each other and, of course, they should agree. The present situation has been examined by the CODATA Task Group on Fundamental Constants based on work published through the end of 2010. They conclude that the present uncertainty of the Planck constant from all relevant experimental approaches is the equivalent of 44 microgram per kilogram.

The CGPM will not adopt the proposed new definitions until present difficulties are resolved. However, on Friday 21 October 2011, the General Conference took a historic step towards the revision by adopting Resolution 1 and thereby outlining the proposed New SI as well as the steps required for the final completion of this project. The text of Resolution 1 is that of Draft Resolution A, which had been publicly available for some months on the BIPM “New SI” website, with only minor changes made during the Conference. One of these asks the International Committee for Weights and Measures (CIPM) to continue its work to render the language of the New SI as far as possible understandable for users in general, while maintaining scientific rigour and clarity and without altering the basic content and structure of the New SI as set forth in Resolution 1.
In the resolution of the most recent meeting, there is a bit more description on how the kilogram will be tied to the Planck constant.

the kilogram will continue to be the unit of mass, but its magnitude will be set by fixing the numerical value of the Planck constant to be equal to exactly 6.626 06X ×10–34 when it is expressed in the SI unit m2 kg s–1, which is equal to J s
the mass of the international prototype of the kilogram m(K) will be 1 kg but with a relative uncertainty equal to that of the recommended value of h just before redefinition and that subsequently its value will be determined experimentally,
Well, there ya go. Looks like some time in 2014, that standard mass will be nothing more than a historical, museum piece, just like the 1 meter rod.


Saturday, November 05, 2011

Three New Elements Join The Periodic Table

Please welcome the three new members of our Periodic Table Club: darmstadtium (Ds), roentgenium (Rg) and copernicium (Cn).

These elements are so large and unstable they can be made only in the lab, and they fall apart into other elements very quickly. Not much is known about these elements, since they aren't stable enough to do experiments on and are not found in nature. They are called "Super Heavy," or Transuranium, elements.

The General Assembly approved these name suggestions proposed by the Joint Working Party on the Discovery of Elements, which is a joint body of IUPAP and the International Union of Pure and Applied Chemistry (IUPAC).
Don't think most of us will be encountering these elements anytime soon.


Friday, November 04, 2011

Surface Tension

This is a nice video of a very good and simple demo of surface tension. Kids, you can try this at home!

Hum... iPhone grip? This was taped using an iPhone?



Wednesday, November 02, 2011

Tunneling Experiment Proposed To Distinguish Superconducting Pairing Origin

It certainly was a nice coincidence that I mentioned about the paper on tunneling spectroscopy on superconductors earlier. It turns out that a new paper proposes an experiment using Josephson tunneling junction to distinguish between the pairing model proposed by 5 different theories.

Now, She et al. lay out in parallel the theoretical expectations for the pair susceptibility of 5 different theories of superconductivity in quantum critical metals. These scenarios include the orthodox BCS theory with a simple Einstein-oscillator pairing function, BCS with a Hertz-Millis-type criticality of the bosonic spectrum, BCS with a simple pairing function and quantum critical electrons, and two limits of the recently developed holographic superconductivity that borrow mathematical concepts from string theory [anti–de Sitter/conformal field theory (AdS/CFT) correspondence] in order to handle scaling near a quantum critical point.
It will be interesting to see which group gets to do this test first, and whether the results can actually distinguish one versus the others. Still, this is a prime example of the tunneling phenomenon being used to study other things.


Tuesday, November 01, 2011

So Many Science Careers!

Another hilarious installment of "Experimental Error" on the Science Careers section. This time, the topic is on the diversity of science careers beyond just academia.

While there's a lot of tongue-in-cheek humor in the article, it is littered with quite a bit of reality. For example:

For example, there was the classic (and, in my experience, largely useless) question about how we each found our current jobs. I could tell that the students really wanted to hear stories about how we noticed a posting on Science Careers or, answered an ad, and survived competition with 200 random applicants -- because that’s their own best idea for how to land a position. Instead, each of the panel members talked about how we found our own careers through serendipitous meetings, friends-of-friends, and good old blatant nepotism.
It is why, kids, that I always tried to emphasize on the "intangibles" when you are in school, such as publishing, going to conferences, being social by meeting others in your field (and outside), etc.. etc. Being isolated and a loner in this field simply reduces your chances of landing a job. It is as simple as that.