And the prize goes to…

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0 Commentsby   |  10.04.11  |  Physics News

The 2011 Nobel Prize in Physics goes to Saul Perlmutter, Brian P. Schmidt, and Adam G. Riess for measuring the acceleration of the universe with supernovae.

These American-born scientists ran two competing groups, the Supernova Cosmology Project started in 1988 and the High-z Supernova Search Team in 1994, which independently published breakthrough papers in 1998.  The motivation for their projects was based on one of the most vexing problems in astronomy: when you look at a star, can you tell how far away it is?  Obviously, they will appear dimmer the farther away they are, so if we know how bright the star really is we can guess its distance fairly accurately.  One classic solution to this problem which has been used since the 1930’s is to look for giant, pulsating Cepheid variable stars where we can infer their brightness based on the time between pulses.  These teams pioneered the use of Type Ia supernovae which are short-lived but extremely bright, meaning that they will be visible from far away.  They used telescopes with CCD sensors which power all of today’s digital cameras to scan a huge patch of sky, then they re-scan the same region a few weeks later to look for signals of a supernovae.  The key to this technique was that when they performed the re-scanned they would also book time at other, more powerful telescopes to zoom in on the supernovae they found.  Both teams were in fierce competition, often even using the same telescopes.

Brightness versus distance of supernovae. The blue dashed lines show accelerating universe models, while the solid black lines have no acceleration.

The second figure 1 (nobody’s perfect) from the summary paper shows brightness versus distance data of supernovae.  The lines show various universe models with different parameters.  These models take Einstein’s General Relativity equations and solve them assuming that the universe is completely homogenous and isotropic (which actually disagrees with current observations showing clusters, filaments, and voids, but these complications make the math unsolvable so we’re pretty much stuck).  We then throw in different ingredients such as matter which likes to stick together with gravity, radiation, and an outward expansion from a cosmological constant called dark energy.  The non-accelerating models with solid black lines show universes with differing amount of matter but no dark energy.  We might expect to be on the (1,0) line, but that disagrees with the data.  Instead, the blue dashed lines showing accelerating universes fit quite well, and seems to improve by increasing the ratio dark energy to matter.

Combination of results from supernovae (SNe), COBE and WMAP satellites (CMB), and spatial correlations of galaxies (BAO).

These measurements were a new take, and an interesting confirmation of, a result from the COBE satellite launched in 1989 to measure the background radiation left over from the Big Bang (but that’s another story), which incidentally won the 2006 Nobel Prize.  (One of the winners, George Smoot, later appeared on “Are You Smarter Than a 5th Grader” where he beat their brains out.  High fives all around.)  When you compare the COBE results to the supernovae results, something truly remarkable emerges.  The overlap of agreement leaves a teeny, tiny allowed region of a nearly-flat, accelerating, forever-expanding universe with roughly 75% dark energy and 25% matter.  (Curiously, the matter that we know of is only a small fraction of this, so we call most of this dark matter.)

Personally, the most interesting thing about these results is that they starkly reveal how little we actually know about the universe.  We know almost nothing about dark energy, and very little about dark matter.  The stuff that we know about comprises about 4% of the universe.  4 lousy percent!  This is 1/25th of the universe.  Contrary to popular belief, we aren’t nailing down the details of the details of the details of the answers, instead we’re just now trying to figure out what questions we should be asking (see this fantastic animation from PhD Comics for more).  Frankly, this makes the universe a much more interesting place to be.

-Dr. D

 

 

Funeral for a Collider

0 Commentsby   |  09.30.11  |  Physics News, Research

Today is September 30th, 2011.  Today marks the end of era in physics.  Today is the last day of the Tevatron.

The Tevatron at Fermilab

Fermilab, which sits outside of Chicago, has an interactive timeline showing some of the milestones of the Tevatron, which was one of the world’s largest atom smashers.  The final pieces were installed on March 18, 1983 (a few weeks after I turned four years old) and broke record after record.  The Tevatron will always be known for the discovery of the top quark in 1995.  In fact, nearly everything we know about the top quark today is due to Tevatron data.  The world’s best measurements of the W mass come from the Tevatron which tell us a great deal about the properties of the Higgs.  It is also noteworthy that the searches for a 4th generation of quarks or supersymmetric particles which turned up empty greatly constrained many theoretical models.  Finally, in a weird twist of fate, as of this moment the Higgs itself has run out of places to hide except for one tiny region just tantalizingly out of reach of the Tevatron.  One small upgrade, a few more years of data, and maybe the Higgs would have been ours.

ACU has worked with Fermilab for many years, and we are still running an exciting experiment which will provide amazing insight into what protons are made of.  Even though Fermilab’s collider program is over, they are still using the main proton beam for experiments such as ours, or the experiment which will check (and most likely overturn) the faster-than-light neutrino measurement from OPERA.

NPR has a nice story here, and for more technically-involved but bleaker updates there is live blogging today from the funeral here.

Texas Physics Programs on the Chopping Block

0 Commentsby   |  09.27.11  |  Physics News

An incredibly disturbing story from Nature News reports on the implication of an announcement by the Texas Higher Education Coordinating Board.  From the article:

…nearly half of the 24 undergraduate physics programmes at state funded universities could be on the chopping block if they fail to graduate at least 25 students every 5 years

If this goes through, we will do real and permanent damage to science education in Texas.  There are countless studies which show that science education is crucial to America’s economy.  I’ll give two specific examples:

  1. The 2008 Rising Above the Gathering Storm report
  2. The research that went into the development of the America COMPETES Act

Apparently our plan to address our economic downtown involves sitting in the middle of a storm, not competing.  To borrow a phrase, it seems kind of like cutting hospitals during a plague.

-Dr. D

The Best-Paying College Majors

0 Commentsby   |  08.02.11  |  Careers, Engineering

Interested in getting the most bang for your college tuition buck?  A new report from payscale.com lists that the top 10 best-paying college majors are all in the closely related fields of engineering, physics, computer science, and applied math.

Let’s take a look at the results sorted by mid-career median pay:

  1. Engineering
  2. Engineering
  3. Engineering
  4. Engineering
  5. Engineering
  6. Engineering
  7. Physics
  8. Applied Math
  9. Computer Science
  10. Engineering

Overall, these results should come as no great surprise.  Discoveries by past physicists have paved the way for the technology we have today (i.e. you have to discover quantum mechanics before you can invent iPhones). Science and technology still drive the economy today, mostly through the products developed by engineers.  For a slightly less-serious take, the Dilbert.com blog even has an interesting post today about the importance of engineering to an economy.

OK, now that I’ve made my point, here’s the list again from payscale.com in lovely chart form showing the actual fields of engineering as well:

Degrees Degrees
Methodology
Annual pay for Bachelors graduates without higher degrees. Typical starting graduates have 2 years of experience; mid-career have 15 years. See full methodology for more.

You have to go pretty far down the list to find a field which does not heavily involve number crunching.   If you’re interested in the other end of the spectrum, or just looking for non-mathematics-based fields, Huffington Post has the  worst paying majors list as a slideshow.

Of course, future salary potential is just one small factor to consider when choosing a college major.  Find a job that you love and you’ll be better off in the long run.  Have fun browsing.

-Dr. D

 

Physics Department Update

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0 Commentsby   |  07.22.11  |  Department, Engineering

I’d like to give you a short status update on the physics department.  I’m motivated to do this do because during the past two weeks I’ve had the opportunity to:

  • welcome 16 of the new students joining our department this fall,
  • attend the ninth Christian Engineering Education Conference, and
  • see first hand how our students are contributing to research at ACU, BNL, and LANL.

If I’m allowed to speak presidentially, then I’d say the state of our department is outstanding.  We have a current group of students that are excellent and accomplishing great things this summer.  Read our latest DANGO reports for more details (see below).  We have a very promising group of students arriving this fall and there are more scheduled for the August passport session that I haven’t had the opportunity to welcome to campus yet, but I look forward to doing that soon.

Finally, the faculty of the Department of Physics has worked extremely diligently over the past year to develop a plan to change us into the Department of Physics and Engineering.  Experts in Engineering, Business, Finance, and Recruiting from both inside and outside of the university have reviewed our plan and everyone has been very supportive.  Clearly there is a great student demand for Engineering and we believe we can develop a world-class engineering program that will compliment our current physics program.  It was exciting to me to attend the Christian Engineering Educators Conference and hear about how Christians who engineer are leading and serving for Christ.  I heard about how faculty and students participate in engineering mission trips and I participated in some discussions of how God is the ultimate designer.  There is definitely a place for engineering at ACU.  Currently we are looking for the right Christian engineering professor to help develop and lead this program.  If you know of a professor that may be qualified, please pass their name on to me.

God has blessed us in many ways and I’m excited about what is in store for the Department of Physics (and Engineering?).

–Dr. Rusty Towell, Department Chair

Life at the Labs

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0 Commentsby   |  06.30.11  |  Research

It is fun and easy to talk about huge colliders, massive experiments, and the latest cool results, but often the day-to-day life gets overlooked.  Curious about cutting-edge physics research as viewed through the eyes of our students?  Well, until the movie comes out you can read our latest Doings ANd Goings On at the link below:

DANGO 2011 – Issue #2

-Dr. D

PHENIX publishes 100th paper

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0 Commentsby   |  06.23.11  |  Physics News, Research

We received word this morning that the 100th peer-reviewed paper by PHENIX has been published online.  To the best of our knowledge, every single paper includes at least one person from ACU on the author list.  The first paper was published in April 2001, and it is an amazing accomplishment by the PHENIX Collaboration to reach this milestone in 10 years.

View the complete list of published peer-reviewed articles on PHENIX’s web page.

Summer 2011 Research

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0 Commentsby   |  06.22.11  |  Research

After a long, beautiful hibernation, we are back with this summer’s physics research!

This summer we’ve got students and professors working in New York, Chicago, Colorado, New Mexico, and Idaho.  Not bad for a physics department from small-town west Texas.  Most of our work falls under the umbrella of nuclear physics by studying the structure of the proton and directly measuring nuclear fission processes.  We also have students who have recently worked on various research projects in medical physics, homeland security, and optics just to name a few.  Of course, the research experience helps our graduates go off to a huge array of different fields in physics, engineering, education, and computing.

My plan is to let you hear directly from the students about their summer research experiences, so for the first time I am posting a copy of our weekly newsletter: the Doings ANd Goings On (DANGO) of the ACU Physics department.  Since our group is quite literally scattered across the country, we have the students and professors write a weekly status update for the DANGO newsletter.  By our records, this is the 17th year of DANGO (and the 30th year of nuclear physics research at ACU).

Research is an inherently messy process.  The User’s Center here at Brookhaven National Lab has a poster with quote from Einstein on the wall:

“If we knew what we were doing, it wouldn’t be called research”

DANGO captures it all.  The joy and the sorrow.  The triumphs and the suffering.  The work and the play.  The serious and the not-so-serious.  The difficult process of doing something which has never been done before.  And you’re welcome to come along for the ride.

Click on the link to download:  DANGO 2011 – Issue #1

-Dr. D

The Art of Science

0 Commentsby   |  10.14.10  |  Fun, Physics News

What happens when 5 of the world’s leading particle physics laboratories open their doors to amateur photographers:  Particle Physics Photowalk.

A research lab can be an imposing place.  The fences, armed security guards, and radiation warnings are enough evoke fear in the public at what really goes on in these government facilities.  Are you conjuring up images of lab coats and death rays yet?

The truth is, the vast majority of scientists who work in particle and nuclear physics want the world to see what our research looks like.  We think our machines are cool, and we revel in playing with some of the world’s neatest toys.  The 200 Photowalk photographers did an amazing job of capturing life inside the lab.  Who knew that physics research could be so, well…, beautiful?

View the finalists on the InterAction Collaborations’s Flickr page.

-Dr. D

The Edge of Science, part 1: the system works

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1 Commentby   |  09.02.10  |  Fun, Physics News

We spend a lot of time talking and writing about being on the cutting edge of science.  We tell colleagues, students, and (mostly importantly) funding agencies that we are dealing with the newest equipment, the biggest atom smasher, the latest technique, and the results hot off the press.  For various reasons I’ve been interested lately in the other edge of science.  For the next few posts I hope you’ll come with me on a journey to the backwaters, the murky regions, and some deep dark spooky places.  Let’s jump off the back edge of science and see what we find.

There is a recent article in the excellent physics magazine Symmetry (available free online, thanks to support from the Department of Energy and Office of Science) about the dismissal of a lawsuit in appeals court.  To get you interested, my favorite quote from last week’s article is:

Accordingly, the alleged injury, destruction of the earth, is in no way attributable to the U.S. government’s failure to draft an environmental impact statement.

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