If you are intrigued by Hubble's deep images of the sky there is a Google Event webinar to discuss the latest findings. The public is invited. show up online and ask questions of the astronomers involved. It is at 1 p.m. Sept. 27 and can be joined either at HubbleSite’s Google Plus page or the HubbleSite YouTube Channel.
Field of Science
-
-
Don't tell me they found Tyrannosaurus rex meat again!1 week ago in Genomics, Medicine, and Pseudoscience
-
-
-
Course Corrections4 months ago in Angry by Choice
-
-
The Site is Dead, Long Live the Site2 years ago in Catalogue of Organisms
-
The Site is Dead, Long Live the Site2 years ago in Variety of Life
-
Does mathematics carry human biases?4 years ago in PLEKTIX
-
-
-
-
A New Placodont from the Late Triassic of China5 years ago in Chinleana
-
Posted: July 22, 2018 at 03:03PM6 years ago in Field Notes
-
Bryophyte Herbarium Survey6 years ago in Moss Plants and More
-
Harnessing innate immunity to cure HIV8 years ago in Rule of 6ix
-
WE MOVED!8 years ago in Games with Words
-
Do social crises lead to religious revivals? Nah!8 years ago in Epiphenom
-
-
-
-
post doc job opportunity on ribosome biochemistry!9 years ago in Protein Evolution and Other Musings
-
Growing the kidney: re-blogged from Science Bitez9 years ago in The View from a Microbiologist
-
-
Blogging Microbes- Communicating Microbiology to Netizens10 years ago in Memoirs of a Defective Brain
-
-
-
The Lure of the Obscure? Guest Post by Frank Stahl12 years ago in Sex, Genes & Evolution
-
-
Lab Rat Moving House13 years ago in Life of a Lab Rat
-
Goodbye FoS, thanks for all the laughs13 years ago in Disease Prone
-
-
Slideshow of NASA's Stardust-NExT Mission Comet Tempel 1 Flyby13 years ago in The Large Picture Blog
-
in The Biology Files
The Hubble Extreme Deep Field
If you are intrigued by Hubble's deep images of the sky there is a Google Event webinar to discuss the latest findings. The public is invited. show up online and ask questions of the astronomers involved. It is at 1 p.m. Sept. 27 and can be joined either at HubbleSite’s Google Plus page or the HubbleSite YouTube Channel.
2012
The Z Machine Makes Stars and Art
I met Don Winget years ago on a cloudy night in the control room of the Otto von Struve Telescope. His enthusiasm and excitement was overflowing. I could hardly see his face, lit eerily by red lights, but his words painted a picture of far away white dwarf stars. These stars are pulsating, cooling, and perhaps intertwined with mysterious undiscovered axion particles. He continues extraordinary pursuits. He is looking for white dwarfs on earth with the Z Machine. The Z Machine releases a powerful electrical discharge over a brief amount of time to create plasma, X-rays, shock waves, and an electromagnetic pulse. The Z Machine releases several times the combined energy output of all power plants on earth for a few brief nanoseconds with each shot. Usually it does nuclear weapons research, but this wonderful research aims to simulate aspects of white dwarf stars on earth and it is inspiring art.
Perseid meteor shower 2012
Discovering the Higgs Boson
Sobre el Futuro and the Lindau Nobel Laureate Conference
Next up I am traveling to Lindau Germany once again to cover the Lindau Nobel Laureate Conference. I will be writing with the Nature blog team. I am very excited to be returning to Lindau this year. I first covered the Lindau Nobel Laureate conference in 2010 and at the time I really didn't know what to expect. I found that Lindau is an amazing place where ideas are exchanged at a rapid pace and discussions of science and the future are pervasive. I love it. I will be attending the conference from the journalist perspective of course so I will be interviewing people, including Nobel Laureates, while at the same time learning and communicating what I discover to a larger audience. If you haven't heard of the Lindau conference before (or even if you have) I recommend checking out the Lindau Mediatheque where they have videos of the lectures given by the Laureates. I am already blogging over on the Lindau blog; the conference starts on July 1st and lasts an entire week. Please go check it out and I will talk to you again from Germany.
Future/Proof
Fusion for the Future: ITER
Fusion is what powers the Sun and all stars in our Universe. Fusion is the joining of two or more separate atomic nuclei into a larger nuclei. Fusion can create energy because the mass of the input and output nuclei are not necessarily equal in mass. An overview of what fusion is and why it is so important can be seen on my previous post on Fusion for the Future. Many scientists in the field acknowledge that a rapid development of fusion is unlikely, much less a commercial development, but there is hope. A reasonable time frame may be half a century before we see a world powered by the same process which drives the Sun. It will be an almost entirely clean, limitless, reliable, and safe source of power.
The key to releasing the energy of the Sun is forcing the nuclei of atoms close enough together for them to overcome their electrical repulsion and allow the strong force which binds nuclei to merge the nuclei together. Such favorable conditions for atoms to smash into each other can only occur under extreme temperatures and pressures, like say at the center of a star, but it is almost impossible to hold a star on earth. Anything which is hot enough to undergo fusion is also hot enough to burn through any container, thus we must contain something without quite touching it. Enter the magnetic doughnut known as the tokamak. A tokamak is a toroidal or doughnut shaped container that uses magnetic fields to confine plasma. Plasma is a state of matter where all the atoms are ionized (the electrons that normally orbit the protons in the nucleus have escaped)—and at these temperatures the atoms contained in the tokamak are definitely ionized. Magnetic fields apply a force on the charged particles of plasma such that the plasma can be corralled and kept away from the walls of the container. In an actual tokamak huge magnets encircle the enclosure as shown in the figure here where the magnetic coils and the ITER plasma surface is shown. The colors and contour lines indicate the magnetic field strength which is not quite perfect, the lines are wavy, due to deviations from perfect symmetry in the structure because the tordioal magnetic field is made of a finite number of magnetic coils. The ITER tokamak will be huge. Check out the tiny little person (bottom left) in the image below.
The complexity of this machine is astounding. One key challenge that must be overcome is the confinement of the plasma in a controlled manner. The Confinement Topical Group will determine exactly how to accomplish the confinement and avoid the performance degrading effects of Edge Localized Modes or (ELM modes). The hotter the plasma is the more internal plasma pressure is that must be balanced by stronger magnetic pressure fields; we could view this system in analogy to a balloon where that the plasma is the air under pressure and balloon's walls are the magnetic fields. The exact ratio of the plasma's internal current, the physical size of the tokamak, and the torodial magnetic field is a carefully tuned parameter to balance the gas temperature and magnetic pressures which does not yet have a known optimal configuration (the goal is I/aB < 2.5 where I is the plasma current, a is the minor radius, and B is the toroidal field on axis). It has been observed that the ELM modes periodically become unstable and have breakouts. This creates a large energy flux in a short time, like that of a solar flare on the Sun, where hot plasma breaks free of the magnetic fields. When this occurs the plasma may touch the side walls of the tokamak and overheat the internal surfaces to many thousands of degrees. The side wall surfaces will be evaporated and eroded inside the plasma chamber. In this way the ELM modes result in the introduction of plasma impurities which contribute to raising the effective atomic number (the number of free protons per particle) of the plasma which results in greatly reduced fusion efficiency or even the halting of the fusion reaction entirely; the target is to keep the effective atomic number below two. The aggregate erosion is large and the lining of the tokamak walls may need be replaced often. In order to operate the machine continuously and cost effectively the ELM modes must be controlled. The control of ELM is paramount for a successful fusion tokamak. In the video below Alberto Loarte tells us a little more about the control of ELM modes and clever ways that the ELMs are dealt with.
The plasma instabilities inside a fusion reactor are a serious engineering challenge, but they are not a safety concern at all. Unlike a fission reactor, when a fusion reactor is compromised it does not go critical in a dangerous explosion (like a fission reactor would), instead it just fizzles out harmlessly. This technology is not perfect though because while some may claim that a fusion reactor would create no dangerous radioactive material in fact it would produce some radioactive material that would need to be handled. It is the walls of the reactor which will become slightly radioactive (through neutron activation). Conveniently though the half life of such radioactive waste materials is less than 100 years and could be entirely handled on site.
We should all be hoping for fusion. I spoke with Michel Claessens, the head of communications for ITER, and one of the questions I asked him was, what should the public know about fusion and ITER?
As much as possible. More seriously, I would be happy if people understood the differences between fission and fusion.And he has a point I think. Most people simply don't understand what is at stake and what our options our. If you are reading this then you are already more informed than most. Tell people about the difference between fusion and fission and encourage your government (no matter what country you live in) to follow a wise energy policy. While I was writing this article the United States changed its funding proposition for ITER which was a welcome change because at one point the United States looked like it would falter on its commitment to fusion research and ITER completely. This is an investment in our future and the Earth. I asked Claessens a question about this topic too, how important is worldwide collaboration in achieving a successful ITER project?
Worldwide collaboration is useful and even necessary - to pool and ensure the best use of resources (human and financial). The ITER project is so complex that no single country has the scientific and technological skills to build the machine alone. In addition, the international collaboration was seen by ITER fathers (Gorbachev and Reagan) as a way out to cold war.The idea of harnessing the power of the Sun on the Earth is so much more than just a scientific endeavor. It is a very human dream to hold the Sun (what culture does not have some kind of original creation story or explanation for the sun?) and it is possible that realizing this dream may bring us together for all of the right reasons.
A Trip to the Moon
Outer Space
Disassociate Galaxy Clusters
- Clusters are made of aggregates of hundreds or thousands of galaxies and each galaxy is made of hundreds of billions of stars. The stars of the galaxy cluster are conspicuous in that they shine and are observable in pictures, but they account for only about 5% or less of the cluster's mass. The luminous stars of galaxies don't interact much during a collision with another cluster of galaxies and so they act like people in two crowds which are moving in opposite directions. Stars are part of the cosmic ghost train.
- The gas in galaxy clusters accounts for about 10% of the regular (or baryonic) mass in clusters. Gas does interact during a collision. The gas clouds in colliding galaxy clusters slams together like two waves of water meeting and stalls out, but not without undergoing a process known as shock heating first which raises the gas temperature to millions of degrees.Gas is part of the cosmic train wreck.
- The dark matter in galaxy clusters is the most dominant part of the cluster by mass making up about 90% the mass. Dark matter does not interact much. The dark matter halos travel right through each other like ghosts when two clusters collide. However, it is possible that the dark matter does interact slightly and dissociative collisions are a powerful tool in constraining this dark matter interaction. The dark matter halos of the colliding clusters should sail right past each other like two ghost trains, but if the trains slow down even in the slightest it may indicate something strange.
In practice many times it is easier to first identify galaxy clusters through their gas content because the gas content is more massive than the stellar component. Many new clusters are identified by observing the cluster gas's effect in the microwave regime or in the X-ray regime. In the image below taken by the the NASA Chandra X-ray observatory the hot intracluster gas is seen in pink. This image corresponds to exactly the same field of view on the sky as the optical image above.
It may dawn on you that by the very definition of dark matter there is no telescope which can observe it directly. The only in way in which dark matter interacts strongly is through gravity and thus that is how astronomers look for it. Through theoretical predictions and confirmed observations we know that gravity bends light and thus massive galaxy clusters will bend the light of even more distant galaxies. Thus through weak gravitational lensing the dark matter betrays its presence. A careful statistical analysis of galaxy shapes in the optical image above reveals that the galaxies which are confirmed not to be in the foreground cluster are slightly distorted in shape via the gravitational force of the dark matter which is in the foreground. A reconstruction of the total mass in the clusters is shown in the image below where the parts of the cluster which have the most mass are shown in blue. This image corresponds to exactly the same field of view on the sky as optical and X-ray images above.
Finally, a superposition of all the data allows us to glimpse at what a crisis this merging cluster is in. Note that the optical image remains in its original color, the gas is in pink, and the mass is in blue. The image below is known as the Musket Ball Cluster. The actual collision of galaxies occurred about 700 million years ago. We can rewind the collisions in our heads and envision that blue/optical cluster on the right of the image was once on the left and so the blue/optical cluster on the left of the image was once on the right; the clusters collided head on and the gas stopped dead at the center, but the galaxies and dark matter hardly stopped. There are several other images below of other dissociative cluster mergers with the same color scheme. Notice the different morphologies and distributions of mass, stars, and gas. The collisions are not always so straight forward.
Train Wreck Cluster. X-ray: NASA/CXC/UVic./A.Mahdavi et al. Optical/Lensing: CFHT/UVic./A.Mahdavi et al.
Bullet Cluster. Credit: X-ray: NASA/CXC/CfA/M.Markevitch et al.; Optical: NASA/STScI; Magellan/U.Arizona/D.Clowe et al.; Lensing Map: NASA/STScI; ESO WFI; Magellan/U.Arizona/D.Clowe et al.
Dawson, W., Wittman, D., Jee, M., Gee, P., Hughes, J., Tyson, J., Schmidt, S., Thorman, P., Bradač, M., Miyazaki, S., Lemaux, B., Utsumi, Y., & Margoniner, V. (2012). DISCOVERY OF A DISSOCIATIVE GALAXY CLUSTER MERGER WITH LARGE PHYSICAL SEPARATION The Astrophysical Journal, 747 (2) DOI: 10.1088/2041-8205/747/2/L42
Jee, M., Mahdavi, A., Hoekstra, H., Babul, A., Dalcanton, J., Carroll, P., & Capak, P. (2012). A STUDY OF THE DARK CORE IN A520: THE MYSTERY DEEPENS The Astrophysical Journal, 747 (2) DOI: 10.1088/0004-637X/747/2/96
Markevitch, M., Gonzalez, A., Clowe, D., Vikhlinin, A., Forman, W., Jones, C., Murray, S., & Tucker, W. (2004). Direct Constraints on the Dark Matter Self‐Interaction Cross Section from the Merging Galaxy Cluster 1E 0657−56 The Astrophysical Journal, 606 (2), 819-824 DOI: 10.1086/383178
Conservation in the Real World
The Most Astounding Fact
Humans are at least 60% water by mass (this is the most uncertain number here because after you drink a few beers this number quickly starts to change). Water is by mass is 11% hydrogen. Thus the mass of hydrogen in our body from water is at least 7% though of course there is lots of other hydrogen in our body from other molecules (lipids, amino acids, and so on). A better estimate is that we are 10% hydrogen by mass (if we do our accounting by number of atoms in the body we are 63% hydrogen atoms). Ultimately every atom in us is that is not hydrogen was forged in stars, and so 90% of the mass in our bodies is stardust.
The Story of Fixing Hubble
Large projects have social forces at play such as 'normalisation of deviance' wherein problems become okay logically when you step back from them. An entire mission can drift noticeably into situations where more than a simple technical argument can stop it. Pellerin took notice of research which shows that social context can be a larger determinate of performance rather than individual abilities. Pellerin asserts that Hubble nor Challenger was a product of invisible or unmanageable forces. While certain accidents may be unavoidable, others are avoidable and they may be the fault of leadership. Today Pellerin teaches management techniques founded concepts of mutual respect, authenticity, and efficient action incorporated into the leadership.
There's nothing unusual about having a bad day at the office. But some people have worse days than others, and in his time Charles (Charlie) Pellerin has had a few notable ones. Not many people find themselves having to explain why an organisation has invested a decade and half and in the vicinity of $3 billion on a project that has failed.
That's the position Pellerin found himself in as NASA's director of astrophysics in the wake of the 1990 launch of the Hubble Space Telescope, which had what appeared to be an unfixable flaw in its optical system.
It's difficult to overstate what a disaster this was and the humiliation faced by NASA; not just as an organisation but also the individuals who worked for the agency. A good friend of Pellerin who worked on the telescope fell ill in the wake of the launch and died. Two of Pellerin's senior staffers had to be removed from their offices by guards and taken to alcohol rehab facilities. "These are PhDs sitting at their desk getting drunk; this is how bad the stress was," says Pellerin.
Read on about how NASA's short-sightedness led to a flaw in Hubble's optics.
Science writing versus writing like a scientist
It as if scientists are bound to a certain kind of writing that is dry, concise (and it has to be when we have to pay per page published in most research journals), and standardized. I think many scientist would agree that our language doesn't have to be dry as long as it is standardized. Expository writing is different from other kinds of writing sure, but we have to ask ourselves how and why? Science writing for journalism is different than that of science writing for papers of grants even though they are both technically expository writing. I wonder if this is because they must be or because mediocre writing has become the style in science papers. Adam Ruben has written a wonderful opinion piece over at Science magazine mocking some of the quirks of scientific paper writing. The piece is worth a read and he includes a list of science paper tropes which are hilarious. Here is an excerpt:
1. Scientific papers must begin with an obligatory nod to their own relevance, usually by citing exaggerated figures about disease prevalence or other impending disasters. If your research does not actually address one of these issues, pretend it does, because hey, that didn’t stop you on the grant application. For example, you might write, “Twenty million children die of scabies every day. OMG we built a robot kangaroo!”
2. Using the first person in your writing humanizes your work. If possible, therefore, you should avoid using the first person in your writing. Science succeeds in spite of human beings, not because of us, so you want to make it look like your results magically discovered themselves.
3. Some journals, such as Science, officially eschew the passive voice. Others print only the passive voice. So find a healthy compromise by writing in semi-passive voice.
ACTIVE VOICE: We did this experiment.
PASSIVE VOICE: This experiment was done by us.
SEMI-PASSIVE VOICE: Done by us, this experiment was.
Yes, for the semi-passive voice, you’ll want to emulate Yoda. Yoda, you’ll want to emulate.
Read on you will want to, like a scientist you must write.
What entropy is or is not
C.P. Snow famously said that not knowing the second law of thermodynamics is like never having read Shakespeare. Whatever the particular merits of this comparison, it does speak to the centrality of the idea of entropy (and its increase) to the physical sciences. Entropy is one of the most important and fundamental physical concepts and, because of its generality, is frequently encountered outside physics. The pop conception of entropy is as a measure of the disorder in a system. This characterization is not so much false as misleading (especially if we think of order and information as being similar). What follows is a brief explanation of entropy, highlighting its origin in the particular ways we describe the world, and an explanation of why it tends to increase. We've made some simplifying assumptions, but they leave the spirit of things unchanged.Read on.
Perspectives on the Vertical
Powers of Ten was originally inspired by a 1957 book by the Dutch educator Kees Boeke titled Cosmic View. By 1963, the Eameses were experimenting with tracking shots that gave the effect of a camera pulling away with accelerating motion from an object, and in 1968 used these in a film called A Rough Sketch for a Proposed Film Dealing with the Powers of Ten and the Relative Size of Things in the Universe. Shot in black and white, it was followed by an extended color version—the one known as Powers of Ten—made in 1977. The basic set-up of the latter film is well-known. It opens with a picnic scene in a park in Chicago. From a ground level view, the camera then switches to a vertical, aerial position from which it looks down, the frame centered—as we later find out—on an atom in the man’s hand. At this point the narrator tells us that we are one meter away and looking at a square one meter by one meter. Now the camera pulls away vertically and begins to accelerate so that every ten seconds our distance from the initial scene is ten times greater. The camera continues its upward trajectory until just after 1024 meters (100 million light years) when it gradually slows and begins its descent, collapsing beyond its original position and now decelerating through the ever-smaller dimensions of cells, molecules, atoms, and beyond.
Read on.
A likely Supernova in M95
The Stars seen from the the International Space Station
ASTRONOMICAL - The Movie
A scale model of our solar system in twelve 500 page volumes printed-on-demand. On page 1 the Sun, on page 6,000 Pluto. The width of each page equals one million kilometres.
This film takes us through the first volume where we encounter the Sun, Mercury, Venus, Earth, Mars and the Asteroid Belt.
Yes, this is just a film of someone flipping through a book that is the solar system to scale. Highlights include the Earth at minute 4:00, Mars at 5:25, and the asteroid belt at 6:40 (actually this is interesting because while even the sun fits on just two pages the asteroid belt spans for several minutes). The entire 12 volume set is available for the discerning and precise sky aficionado. Strange. Cool. Want.
The Thorium Dream
Thorium may be the nuclear fuel of the future. It is clean, abundant, and safe. Check out this video made by the crafty folks at motherboard.tv documenting the grassroots movement to bring back thorium from the dustbin of history.
Sunset
What does the sunset look like on HD 189733 b? Amazingly, we know quite accurately. This is because the colour of the sunset is exactly what is measured when collecting the transmission spectrum of the atmosphere of a transiting planet. We have measured the transmission spectrum of ’189 with the STIS spectrograph on the Hubble Space Telescope. STIS covers visible wavelengths, and HD 189733 is bright enough that the precision of the spectrum is sufficient for a precise translation into colours perceived by the human eye.
What does the sunset look like on HD 209458 b?
Temporal Cloak
I’ve been saying for a few years that optical science has entered a truly remarkable new era: instead of asking the question, “What are the physical limitations on what light can do?”, we are now asking, “How can we make light do whatever we want it to do?” Among other things, we can make light travel “faster than light“, we can focus light through a highly scattering material, we can take high-resolution pictures with low-resolution sensors, and even make particles “fly” on a “wind” of light!Read on.
Inevitably, though, many of these discoveries get misinterpreted in popular news accounts to the point that their real significance is lost in a haze of science fictional, or even supernatural, hype. A good example of this is the “picosecond camera” that I described last week, which is an amazing achievement but also possesses a number of technical limitations that make it not quite a “camera” in the ordinary sense of the word.
This week, the experimental realization of a “space-time cloak” or “temporal cloak” by researchers at Cornell University has made national news.