Authors: A. Klassen, R. Gómez-Herrero, R. Müller-Mellin, B. Heber, R. F. Wimmer-Schweingruber, A. Opitz and J.-A. Sauvaud.<br />Astronomy & Astrophysics Vol. 528 , page A84<br />Published online: 04/03/2011<br />
Keywords:
interplanetary medium ; acceleration of particles ; shock waves.
The One We Love
One of the most beloved, well-known, and beautiful members of the solar system is its very heart; the Sun. You see it every day, you learn about it in school, and you know that life itself couldn’t exist on Earth without it. We now have the STEREO spacecrafts, and can see exactly what the Sun looks like right this minute. It’s fascinating. Of course, I think everything about the Sun is fascinating.
For one thing, just look at it:
NASA/STEREO
Gorgeous, isn’t it? We know a lot about our sun — as well we should. We’ve been thinking about it every since we had the brain capacity to “think” about anything. This near-perfect sphere accounts for over 99% of all the mass in the solar system, its spectral class is G2V (we went over that, remember?), and it generates energy through nuclear fusion. That’s the fusion of two atomic nuclei to form one “heavier” nucleus. It takes a lot of energy to force two nuclei close enough together for them to fuse, but the process releases more energy (in the form of “free” neutrons) than it uses (until you get to iron). The end result is this continuous outpouring of the energy which fuels all life on Earth.
Life cycle of the Sun, by Oliver Beatson - image released to public domain by author
Our understanding of the Sun hasn’t always been so neat and scientific, of course. The Sun was worshiped as a god by early civilized man; and probably back into prehistory. Solar eclipses were occasions of horror. When we gave up on the idea that the Earth was the center of the universe, the Sun was the next logical choice.
Ancient Chinese print - Chinese solar diety Tai Yang Xing Jun
Once it became clear that the Sun was a physical thing and not a deity, early man pondered the mystery of its energy source. After figuring out that it couldn’t be a huge fire burning off in the distance (hey, it makes sense if you know next to nothing about the universe around you), it wasn’t until the 20th century that the true nature of the Sun was known. The Pioneer spacecrafts gave us our first really good look, returning detailed information about the solar wind and magnetic field. Now we’ve had SolarMax, SOHO, and STEREO to give us a greater understanding, and appreciation, of our parent star.
Egyptian god Ra in his solar barge
Our Sun, at 4.6 billion years old, is still a relatively young star. It is about one-half way through its time as a main sequence star (the time it fuses hydrogen into helium). After about 5 billion more years, it will enter a red giant phase. Our star doesn’t have enough mass to supernova. It will end its life as a white dwarf, slowly releasing its remaining heat into space. The very end of its life is theorized to be as a “black dwarf”, a cold, burned-out cinder. Such a thing is purely theoretical since the universe isn’t old enough for one to have formed yet. Still, it makes sense.
NASA/STEREO Behind - the Sun today, March 3, 2011
The more we know about the Sun, the more fascinating and mysterious it becomes. We have always looked to the stars in awe, and lest we forget, the Sun is a star. In every sense of the word.
Hubble’s Look at NGC 2841
NASA's Hubble Space Telescope reveals a majestic disk of stars and dust lanes in this view of the spiral galaxy NGC 2841, which lies 46 million light-years away in the constellation of Ursa Major (The Great Bear). This image was taken in 2010 through four different filters on Hubble's Wide Field Camera 3. Wavelengths range from ultraviolet light through visible light to near-infrared light. Click for a larger version. Credit and image: NASA, ESA, and the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration
Ursa Major, aka: the Great Bear, Big Dipper or the Plough depending on your location, to our eye is a beautiful and very well known constellation. At first glance it appears to be devoid of structures other than the stars that create the pattern.
Nothing could be further from the truth, I’ve spent hours looking around with a telescope and it’s amazing what is really there.
Take this galaxy for example, NGC 2841, a wonderful example of a non-barred spiral galaxy – actually called a Flocculent Spiral Galaxy. You too can see this just point your telescopes at R.A. 9h 22m 02.64s Dec. +50° 58′ 35.47″, dark skies will be required as the magnitude of this galaxy is a little over 10. Well why not? It is 46 million light-years away.
While your view won’t match this amazing Hubble image, you will still get a sense of satisfaction by seeing it for yourself. That said, just look at this amazing image! Click it for a larger version, even better go to Hubblesite to see the full sized versions.
A Quick Glance Back
Conceived in the late 1960′s (before Apollo 11 landed on the moon), the Space Shuttle program was launched on January 5, 1972. Initially proposed to be completely reusable, the final design sacrificed the external tank. The external tank was originally larger, and was to be carried into orbit and used in a future space station.
NASA - Some of these look pretty cool.
The first orbiter, Enterprise, rolled out September 17, 1976. Of course, Enterprise was never intended to go into orbit. It was a glider; built without engines or heat shield. It performed test flights in the atmosphere. It is now the property of the Smithsonian Institution.
The first true space shuttle was the Columbia, delivered March 25, 1979. Columbia launched May12, 1981, the anniversary of Yuri Gagarin’s space flight. The Shuttle completed 27 missions, and was destroyed at the end of its 28th.
Next was Challenger, completed in July, 1982. It completed 9 missions, and was destroyed at the beginning of its 10th.
Discovery, November 1983, completed 38 missions, and is currently on its 39th.
Atlantis, April 1985, completed 32 missions.
Endeavor, May 1991, completed 24 missions.
NASA - Maiden launch of the Program
The Shuttle Program is now facing mandatory retirement, as you know. Originally, the program was to be followed by the Orion Spacecraft and the Project Constellation; however, all future plans for the US to participate in manned spaceflight are now shelved. This gap will supposedly be filled by the private sector.
No matter how many times I write that, I just cannot come up with anything nice to say following that statement. So-o-o-o-o-o-o-o….
Let’s look back with appreciation on all the Space Shuttle program has accomplished, including missions to SpaceLab, ISS, and MIR. It serviced Hubble, transported equipment and crews, became a lab for experiments, and was instrumental in the success of the Galileo spacecraft and the Ulysses and Magellan probes.
Goodbye. We’ll miss you.
NASA - Atlantis into orbit
Stuff!
Rhea, Dione and Saturn's rings by Cassini. Image Credit: NASA/JPL/Space Science Institute
Time for a stuff post or at least a mini stuff post.
Aurora – keep an eye on the K index as night falls. The K-index has hit 5 today and as you know that could mean there is a possibility of seeing an aurora if you live at sufficiently high latitudes. Remember last week I mentioned the possibility? It had clouded up so I wasn’t able to see anything BUT there was a nice video released by the Solar Dynamic Observatory of the flare causing the ruckus. See it here.
Out for a walk – The Discovery space-walkers spent six-hours and 34 minutes outside the spacecraft and ISS. Mission specialists Steve Bowen and Al Drew moved a failed ammonia pump module installed an extension cable, extended the rail track along the station’s main truss and installed a camera wedge among other things. There was a minor glitch caused by a problem with the robotic arm controls in the cupola. Things got back to normal with the operators of the Canadarm2, Mission Specialist Michael Barratt and station Commander Scott Kelly moved to a duplicate control center in the Destiny Laboratory.
Message in a Bottle – Before the spacewalk ended Bowen and Drew opened a metal canister. The goal was simple use the metal canister to capture a bit of the vacuum of space. The canister which was autographed by astronauts will be returned on Discover for display.
Dawn and Messenger – both spacecraft are getting closer to their targets but more on that later.
Cassini – Cassini is still out there and I really like the image above. The image is looking beneath the heavily cratered southern portion of Saturn’s moon Rhea from the opposite side of the moon facing Saturn and toward the wispy moon Dione which is facing Saturn. Dione appears to be sitting on Saturn’s rings, in reality the moon is beyond the rings.
And finally!!!!!
DON’T FORGET TO PARTICIPATE IN THE GLOBE AT NIGHT PROJECT – CLICK TO FIND OUT HOW, GO ON AND DO IT!
Robonaut -1
Click here to view the embedded video.
A view of the STS-133 vapor trail as seen from a balloon with student payload at 110,000 feet. Yes a student payload – very cool stuff!
From onorbit.com:
Last week a balloon with a student-oriented payload shot high resolution photos and video from an altitude of over 110,000 feet of Space Shuttle Discovery as it climbed into space.These images and video were released today as part of a mission report provided by Quest for Stars representative Bobby Russell at the Next-Generation Suborbital Researchers Conference (NSRC) at the University of Central Florida. More information on this conference can be found at http://nsrc.swri.org
Read the rest of the story at OnOrbit and be doubly-doubly sure to go to the link in the article (yeah it’s the very next paragraph) and I’ll include it here, watch the balloon pop video.
There is a Robonaut – 2 also, it’s onboard STS-133!
What a great project, wow, just wow. 
Discovery Launch As Seen From a Plane
Click here to view the embedded video.
I saw still of this but didn’t know there was a video. Check it out!
Thanks and hat tip to Rob
NCBI ROFL: Smelly Week: Smelling like rubber makes your face look uglier. | Discoblog
It’s smelly week on NCBI ROFL! All week long we’ll feature the funniest papers about the science of stink. Enjoy!
Olfactory cues modulate facial attractiveness.
“We report an experiment designed to investigate whether olfactory cues can influence people’s judgments of facial attractiveness. Sixteen female participants judged the attractiveness of a series of male faces presented briefly on a computer monitor using a 9-point visual rating scale. While viewing each face, the participants were simultaneously presented with either clean air or else with 1 of 4 odorants (the odor was varied on a trial-by-trial basis) from a custom-built olfactometer. We included 2 pleasant odors (geranium and a male fragrance) and 2 unpleasant odors (rubber and body odor) as confirmed by pilot testing. The results showed that the participants rated the male faces as being significantly less attractive in the presence of an unpleasant odor than when the faces were presented together with a pleasant odor or with clean air (these conditions did not differ significantly). These results demonstrate the cross-modal influence that unpleasant odors can have on people’s judgments of facial attractiveness. Interestingly, this pattern of results was unaffected by whether the ...
14 billion years in 7 minutes | Cosmic Variance
You’ve already heard about TEDx from Sean here and here. The main TED conference for 2011 has been going on this week, in Long Beach, and rumors have it that it’s been great. Physicist Janna Levin gave a talk, which is not yet posted. A few of the talks are, though — check out this inspiringly optimistic view of the current situation in the Arab world from Wadah Khanfar. More TED talks here, the ones from this week are starting to appear.
In any case, one of the first very large TEDx Events was organized as a part of Universal Children’s Day in November, with a whole bunch of simultaneous organized events called TEDxYouth. I had the opportunity to give a talk at one of the events TEDxYouth Castellija, to about 400 middle and high school students, about how the Universe works.
Because of the younger audience, they cut the standard ted talk time of 18 minutes to 6 minutes, which made it even harder — at least for those of us used to having a whole hour to say something! Anyways, I managed to try to explain dark matter, galaxies, and the last 14 billion years in this short time. You can take a look here:
The rest of the speaker lineup was really great, and very diverse, including a graffiti artist, the founder of guitar hero, the google chef, and a super compelling biochemist.
My favorite talk was by Garang Akau, one of the lost boys of Sudan, who has subsequently graduated from Stanford and started his own NGO called New Scholars, focused on incubating youth-led enterprise in Africa. His fearlessness and optimism in the face of incredible hardship was seriously inspiring. Check it out:
The best part of the whole thing was meeting and talking with some of the kids, who were truly engaged and curious. Lots more awesome talks are available from TEDxYouth Castelleja and from the rest of the TEDxYouth events. Looks like the day was a smashing success all around, and will be happening again next November.
Interview with Suicide Girls | Bad Astronomy
An interview I did with Keith Daniels of the counter-culture site Suicide Girls is now up on the SG website.
I’ll be clear: that page should be OK, but the site itself may be somewhat more than NSFW, in much the same way that standing a meter away from a supernova is somewhat more than Not Safe For Staying a Solid.
I’ve been a fan of SG for a while — it gives a strong, nerdy voice to decidedly non-mainstream thinking in a wide variety of topics, and the interview is like that. We covered a lot of ground: Hubble, NASA, skepticism, politics, life on other planets, the media, and of course Not Being a Dick (while still maintaining a motivating level of anger and passion).
Clearly, after ten years or more of doing interviews, I still haven’t learned how to make a succinct, pithy point. And while I do suffer a bit from verbal diarrhea, I’ll note that some topics deserve more subtlety and longer discussion. Sound bites tend to gloss over vital details, and not everything can be adequately covered by a bumper sticker.
To give you ...
Ride an SRB video into space | Bad Astronomy
NASA has posted video taken from cameras mounted on the solid rocket boosters of STS 133, the Shuttle mission currently underway. It’s pretty amazing to watch:
Most of the video is silent. However, at the 14:46 mark the video cuts to a camera equipped with sound, and although the Orbiter is well out of the part of Earth’s atmosphere where sound can carry, the metal in the booster itself — as you can hear — is more than enough to transmit sound!
After about a minute in you can see the shadow of the plume on the ocean, and at the 2:25 mark… well, it gets pretty exciting. You’ll see. If there’s some moment in particular you like, leave a comment below and let others know!
Credit: NASA. Tip o’ the nose cone to Barbara at Spasms of Accomodation for helping me find this video.
Chernobyl Plants & Temperate Caves Could Help Humans Colonize New Worlds | 80beats
Humankind’s experience visiting worlds beyond our own begins and ends with the dozen Apollo astronauts who skipped about on tiny swaths of the moon. But that doesn’t mean we can’t experiment with how and where we might visit (or live) on the extreme surfaces of other worlds. A few studies out recently are doing just that.
Radiation? Big deal
Our planet provides a protective shield from the most damaging radiation produced by the sun—a shield not available on the moon or Mars. It’s a hazard for any human leaving the planet, and it’s a hazard for plants, too.
However, a new study of the Chernobyl area in the Ukraine, site of the famous nuclear accident, is actually raising hopes for space farming.
Even 25 years after the catastrophic nuclear accident at Chernobyl, the area around the site harbors radioactive soil. But researchers working there have found that oil-rich flax plants can adapt and flourish in that fouled environment with few problems. Exactly how the flax adapted remains unclear, but what is clear is that two generations of flax plants have taken root and thrived there, and ...
Fractal Black Holes on Strings | Cosmic Variance
Here’s a fascinating new result about black holes in five dimensions — actually from last October, but I missed it when it came out. I just noticed it this week because of a write-up by Gary Horowitz in Matters of Gravity, the newsletter of the gravity group of the American Physical Society. (I obviously missed David Berenstein’s post as well.)
You might be thinking that black holes in five dimensions can’t be that interesting, since they are probably pretty similar to black holes in four dimensions, and after all we don’t live in five dimensions. But of course, there could be a fifth dimension of space that is compactified on a tiny circle. (Of course.) So then you have to consider two different regimes: the size of the circle is much larger than the size of the black hole — in which the fact that it’s compact doesn’t really matter, and you just have a regular black hole in five dimensions — or the size of the circle is smaller than the black hole — in which case, what?
The answer is that you get a black string — a cylindrical configuration that stretches across the extra dimension. This was figured out a long time ago by Ruth Gregory and Raymond LaFlamme. But they were also clever enough to ask — what if you had that kind of cylindrical black hole, but it stretched across a relatively large extra dimension? That sounds like a configuration you can make, but it might be unstable — wiggles in the string could grow, leading it to pinch off into a set of distinct black holes. One way of seeing that something like that is likely is to calculate the entropy of each configuration; for long enough black strings, the entropy is lower than a collection of black holes with the same mass, and entropy tends to grow. Indeed, Gregory and LaFlamme showed that long black strings are unstable. However, it wasn’t clear what exactly would ultimately happen to them.
The problem is this: there is a singularity at the center of the black string. If the string simply divides into multiple black holes, that singularity should (at least for a moment) become “naked” to the outside world, violating cosmic censorship. Cosmic censorship is a conjecture, not a theorem, so maybe it is violated, but that would certainly be interesting.
What Lehner and Pretorius have done is to numerically follow the decay of an unstable black string, much further than anyone had ever done before. They find that yes, it does decay into multiple black holes, and the strings connecting them seem to shrink to zero size in a finite time. The implication seems strongly to be that cosmic censorship is indeed violated, although the numerical simulations aren’t enough to establish that for sure.
The cool part is the way in which the strings decay into black holes. They form a self-similar pattern along the way — a fractal configuration of black holes of every size, from the largest on down. Here’s a result from their simulations.
Beautiful, isn’t it? As the string shrinks in radius, it keeps beading off smaller and smaller black holes. Eventually we would expect them all just to bump into each other and make one big black hole, but the intermediate configuration is complex and elegant. And cosmic censorship is apparently violated when the strings finally shrink to zero radius. So it goes.
Little chance we’ll be observing any of this in an experiment any time soon. But Nature has the capacity to surprise us even if we’re just solving equations that are many decades old.
A drug called “Charlie Sheen” | The Intersection
Everyone seems to be speculating about Charlie Sheen. The media paints things any way they want, and as a blogger, admittedly, with this post I add to the hullabaloo. But I’d like to contribute something to the conversation. I’ve seen Dr. Drew describing Sheen’s unusual behavior as possibly “drug induced,” bipolar, and/or manic. Meanwhile, he has reportedly tested negative for drugs and Neil DeGrasse Tyson recently tweeted:
Now I don’t know Charlie Sheen and cannot imagine what his lifestyle is really like. The media’s portrayal is assuredly not the full story.
That said, I suspect he may have more dopamine receptors dotting the tips of his nerve cells than the average man. Dopamine is a powerful chemical associated with craving, desire, and stimulation of pleasure-pathway nerves in the brain. As I explain in my book, research suggests that a high number may predispose us to sexual promiscuity or addictive behavior.
Should this be the case, then Sheen would be–as he describes–literally on a drug called “Charlie Sheen.”
Diluting Felicia | Bad Astronomy
It’s not hard to describe just how silly homeopathy is — after all, diluting a substance in water until nothing is left is clearly not a great way to base a medicinal practice. Unless you’re trying to cure dehydration. But if describing homeopathy’s silliness is easy, doing it well is another matter; most people don’t have a very good sense of scale when it comes to very big and very small numbers (I guess numbers that dwarf even a trillion weren’t necessary for our ancestors on the plains of Africa, so we never evolved a way to grasp them).
However, Steve DeGroof at MadArtLab (the same guy who does the skeptic web comic Tree Lobsters) has found a way to put homeopathy into perspective: use Felicia Day!
[You really must click through to see the whole thing.]
Well, pictures of her, anyway, and the concept of Felicia’s uniqueness. This is actually a pretty good analogy: you can put Felicia into various categories (like women named Felicia, redheads, guest stars on "House"*, and so on) and compare that number to how much homeopathy dilutes various solutions.
I think this ...
Is the Planet Warming? New research suggests the answer could depend on wording | The Intersection
Taeggan Goddard over at Political Wire sent over this interesting piece on research out of The University of Michigan. A new study found that the language used to describe our warming planet may influence listeners’ reactions.
According to research by Schuldt, Konrath, and Schwarz, Republicans are less likely to say that global climate change is real when it’s referred to as “global warming” (44.0%) instead of “climate change” (60.2%). Meanwhile, word choice does not seem to matter for Democrats. The investigators observed the partisan divide dropped from 42.9 percentage points when they used “global warming” to 26.2 percentage points when they used “climate change.”
In other words, language matters tremendously and the outcome of polls can be highly dependent upon it.
On Not Persuading the Unpersuadable | The Intersection
James Hrynyshyn has a new post up entitled “Why it’s hard to change a climate denier’s mind.” He uses it to channel the insights of Simon Donner, who argues that throughout the history of, like, all of humanity, people have considered themselves powerless to influence the climate. So why would that suddenly change?
I don’t doubt that this is a factor. However, it isn’t a partisan one; it suggests incredulity about human-induced climate change should be equally distributed across the populace.
Yet we know this isn’t the case. We know Republicans are much less accepting of climate science, and the idea that global warming is a problem, than Democrats and Independents.
We also know that those with “egalitarian” and “communitarian” value dispositions are much more concerned (and accepting of the science) than those with “individualist” or “hierarchical” value systems. For more on this, listen to my podcast with Dan Kahan.
So: I’m afraid I’m sticking with the view that partisanship and values, rather than anything hardwired about how we understand climate and weather, is the driver here. (At least in the U.S. context. I would guess that if you had a populace that wasn’t politically polarized, the factor Donner is highlighting might then come to the fore.)
P.S.: If you want to see some unpersuadables, check out this thread.
Science writing I’d pay to read | Not Exactly Rocket Science
“That’s brilliant. I’d pay good money for that.”
I’ve been saying this a lot recently. My RSS reader, Twitter stream and other sources of incoming goodies have been chock-full of stand-out pieces – posts that are long, thorough, beautifully written, and most of all, unpaid. Have a look at Greg Downey’s opus on the biology of holding your breath, or Delene Beeland’s piece on Ethiopia’s church forests, or Brian Switek’s post on human origins, or Bora Zivkovic’s tour de force on clock genes, or Steve Silberman’s… well pretty much everything by Steve Silberman.
I read these pieces in amazement that their writers should stick them up for free, when so many others pen far lesser works for a salary. Clearly, the writers are happy to provide free content and they get various advantages out of it. But I absolutely believe that good writers should be paid for good work. I read these pieces and think, “That took a lot of effort. It’s a shame they didn’t get paid for that. I’d pay good money for that.”
And then, last week, I thought, “Hey, why don’t I pay good money for that?”
So I’m going to. As of this month, I am putting my money where my mouth is and trying to set an example. The basic idea: every month, I’m going to choose ten pieces that I really enjoyed and donate £3 to the author as a token of my appreciation.
To clarify the rules further:
- This excludes pieces written for paying mainstream institutions. This is for rewarding people who give content freely. I include bloggers who belong to paying networks like Discover, Scienceblogs and Wired, on the grounds that their rewards are fairly small and are typically based on traffic not, say, word count. So a great, long post may get no views (and earn no money) because it doesn’t have Lady Gaga in the URL.
- There are no formal criteria about things like topic, length, style and so on. I naturally gravitate towards long-form journalistic pieces aimed at general audiences, but posts can make the list for all sorts of reasons not limited to making an important point, making me laugh, or being beautiful. Basically, whatever I enjoy with all the subjectivity that involves.
- The number of pieces and the donation per piece may change as we go along – maybe more pieces, and less money for each – but they seem like reasonable figures for now and not vastly different from what, say, the Times charges for its paywall.
Of course, at £3, the reward to the author is pretty trivial but this is more of an acknowledgement that I as a reader enjoyed the work and felt it was worth my money. People might not want it or feel weird about it. That’s fine and probably expected, (although I would hope that no one would actually take offence at the idea) and I’ll just redistribute among the other candidates. But I do feel that these personalised micropayments are a bit unexplored and I want to explore them.
Then, there are the not inconsiderable logistical problems. How do I actually get the money to people? For the moment, I’m going to do it primitively-as-you-like. I will contact people on the list myself about their Paypal accounts, if they have them. Londoners can claim a pint off me, if they prefer (yes, that’s what booze costs in London).
Ultimately, I’d love to have some way for readers to make similar donations if they so chose to – otherwise, this might just turn into a small group of people swapping money. Maybe a Paypal button on the side, where all the proceeds in a given month are split between the chosen writers for that month? Or a button for each writer? Or maybe one where donations are split between me and the others? I’m open to suggestions about how this could work and whether readers would be happy to contribute.
In an ideal world, every blogger would have a Paypal button or similar on their site that I could click on. Some people find that uncomfortable; some networked bloggers can’t actually install one (for technical or policy reasons). Alternatively, everyone could use something like Flattr – it’s a great model, but it runs into the same problems. There could be a third-party site where people could register their Paypal accounts? Again, I’m keen to hear any suggestions.
I know this might all sound a bit strange to a lot of people and I cannot stress enough that this is a giving initiative, not a collecting one. I’m not asking everyone to start demanding money for their work. I’m saying that good writers are finding it increasingly difficult to make a living because companies are increasingly unwilling to pay good money for good writing. And that would be to everyone’s detriment. To an extent, I think it falls to the consumer to support good writing financially and, as a consumer, I am willing to do my part.
And without further ado, my picks for February. I will be in touch with these fine people soon:
- Human (amphibious model): living in and on the water, by Greg Downey
- Circadian clock without DNA–History and the power of metaphor, by Bora Zivkovic
- Hidden Light: The Visual Language of an Autistic Photographer, by Steve Silberman
- Iron-deficiency is not something you get just for being a lady, by Kate Clancy
- Ancestor Worship, by Brian Switek
- Running out of antibiotics — and other drugs too, by Maryn McKenna
- How IBM’s Watson Computer Excels at Jeopardy!, by John Rennie
- Saving Ethiopia’s Church Forests, by Delene Beeland
- The Mere Existence of Whales, by Carl Zimmer
- Science education for all, by Alice Bell
The Genetic Gamesmanship of a Seven-Sexed Creature | Discoblog
What could be better than two types of sexes? For one organism, the answer isn’t three, but seven! And to top it off, these seven sexes aren’t evenly distributed in a population, although researchers have now developed a mathematical model that can accurately estimate the probabilities in this crap-shoot game of sexual determination.
Meet Tetrahymena thermophila, which in addition to its seven different sexes—conveniently named I, II, III, IV, V, VI, and VII—has such a complex sex life that it requires an extra nucleus. This fuzzy, single-celled critter has a larger macronucleus that takes care of most cellular functions and a smaller micronucleus dedicated to genetic conjugation.
The other odd thing about this one-celled wonder is that the population of the seven sexes are skewed, leading Unversity of Houston researcher Rebecca Zufall and her colleagues to ask: What gives?
To answer that question, they created mathematical models of T. thermophila populations, and discovered that different versions of the same gene, or alleles, gave advantages to different sexes. Unlike humans, in which an individual’s sex is fully determined by its genes, the genotypes of these creatures provide only probabilities of developing ...
IR M63. What RU? | Bad Astronomy
Y’know, I’ve posted a lot of really pretty and cool pictures of spiral galaxies lately, and I’ve given descriptions of how they have black holes in their cores, and how the spiral arms form, and where stars are being born, and and and.
So you know what?
Boom! There you go. [Click to galactinate it.] No fancy explanations, no expounding on the ethereal beauty of dust lanes in an infrared picture from Spitzer, no lectures on anything. Just a really, really pretty picture.
I mean, I could mention how this galaxy, M63, is nearby at only 37 million light years, and how I’ve seen it myself through my telescope. But no, I won’t do that. Nothing about the prevalent short, stubby arms — called spurs — or ring of dust circling the core. And certainly nothing on how the starlight has been subtracted from the image so all you see is warm dust.
Nope. Just the picture.
Pretty, isn’t it?
Image credit: NASA/JPL-Caltech
Related posts:
- Gallery: Spitzer’s greatest hits
- The Milky Way’s (almost) identical twin
- A galaxy that’s all hat and no head
