"The Earth's atmosphere is an imperfect window on the universe... atmospheric turbulence blurs the images of celestial objects, even when they are viewed through the most powerful ground-based telescopes." -John Bahcall
There's no doubt that the Hubble Space Telescope has given us some of the most spectacular, high resolution views of the Universe. From the most distant galaxies ever seen to stars here in our own galactic backyard, the Hubble Space Telescope has simply dwarfed anything we've been able to do from Earth's surface.
This is the globular cluster NGC 288, separated by just over 1 degree from the famed Sculptor Galaxy, as seen through a simple 3" telescope. Larger telescopes can, of course, do better, but from high above the Earth's atmosphere, Hubble's 2.4 meter primary mirror has given us this view of this remarkable object.
Absolutely amazing! For over 20 years, Hubble has been returning images like this, with a resolution of just a couple of hundred-thousandths of a degree!
The reason it can do this, of course, isn't its size. At 2.4 meters, Hubble is pretty large, but we have plenty of 8-meter and 10-meter telescopes here on Earth, which could get much better resolution than Hubble if they were in space. No, Hubble's advantage is its location.
While ground-based telescopes have the entire atmosphere to contend with, complete with turbulent air, a slew of different, moving layers, and intervening molecules, Hubble is literally above all that. Despite their extra size, ground based telescopes haven't been able to compete because of the atmosphere.
But a new technology -- adaptive optics -- is changing all of that. Here's how it works.
You start by shooting a powerful laser with very well-defined frequencies, like this sodium laser, creating a guide star that's in the direction you're taking your observational data. You're seeing light from all of the actual stars, galaxies, etc. -- you know, the real observing targets -- as well as your artificial guide star. The beauty of using a sodium laser is that, around 100 km up, there's a thin layer of sodium in Earth's atmosphere that will absorb and re-emit the light back towards your telescope.
All the light that comes in, both from your real targets and from your guide star, gets distorted by the atmosphere. But, since you know what your guide star is supposed to look like, you can take the blurred, incoming signal from the guide star, and compute what type of weird, fun house-style mirror you'd need to un-blur the image!
Just like a fun house mirror distorts normal images, the right fun house mirror can fix distorted images, if you create just the right mirror. But if you can create the proper mirror to fix the guide star (i.e., the light from the laser), you can also fix the light from your observing targets! Creating a system that continuously adapts its mirror to the changing atmosphere, giving you an undistorted image of your observing target at the end, is the end-all goal of adaptive optics.
(Video credit: 3 minute visualization of an AO system, by Gemini Observatory.)
And when this is put into practice, adaptive optics is capable of taking what looks like turbulent, nonsense noise and turning it into a crystal-clear, real-time image of what actually lies out there in the Universe.
Want to see it in action? Take a look at this 2006 video of adaptive optics taking on a binary star system; you seriously won't believe it.
Just a couple of months ago, Gemini South Observatory released their first light image from GeMS/GSAOI, the world's most advanced adaptive optics system, attached to the 8-meter Gemini Telescope. And wouldn't you know which object they happened to take a look at for their very first image?
Wouldn't you know: it's globular cluster NGC 288! As the GeMS Principal Investigator, François Rigaut was absolutely amazed at this image, and said,
We couldn't believe our eyes! The image of NGC 288 revealed thousands of pinpoint stars. Its resolution is Hubble-quality - and from the ground this is phenomenal. This is somewhat uncharted territory: no one has ever made images so large with such a high angular resolution.
Although all of that is true, I think University of Toronto Astronomer Roberto Abraham more encapsulated my reaction to this image, when he said,
This is fan-freaking-tastic!!!!!!!
And it is! If you horizontally flip and (slightly) rotate the raw image, you can actually overlay it atop the Hubble image back at the top of the page, and compare these two directly!
At this zoomed-out resolution, it doesn't look all that impressive, especially considering the monochrome nature of the ground-based image.
But let's take a look at a very small region -- those four bright horizontal stars towards the center of the above image -- with both the Hubble Space Telescope and the Gemini telescope with the new adaptive optics!
Even at first light -- with its very first image -- the GeMS/GSAOI adaptive optics were easily just as good as Hubble's resolution, the first time that a ground-based telescope has ever done that!
Of course, that was like, two months ago already, so Gemini has since gone on to take even higher resolution images than Hubble can, like this one of NGC 2362.
Sorry that there's no Hubble image of this to compare with, only a Spitzer image that really looks like a joke, particularly next to the full-resolution Gemini version. When you're looking at the image above, remember that each quadrant is less than one ten-thousandth of a square degree! Highest. Resolution. Image. Ever.
And that's how you defeat Hubble without ever leaving the ground!
"In science, "fact" can only mean "confirmed to such a degree that it would be perverse to withhold provisional assent." I suppose that apples might start to rise tomorrow, but the possibility does not merit equal time in physics classrooms." -Stephen Jay Gould
Imagine my disappointment when I read this, and realized that the "6 Scientific Discoveries that Laugh in the Face of Physics" turn out to all be things that physics understands and can explain! Looking at it today, you can see that well over 1,000,000 people have read this, so let's see if we can't get the correct information back out there to as many of them as possible. Without further ado, let's take a look at these six scientific discoveries, and do our best to get it right!
Above is the Sun's Corona, visible only during a total solar eclipse, as shown above. And while the surface of the Sun is very hot, at something around 5800 K, the Corona comes in at temperatures over one million Kelvin. Mysterious, mind-boggling and inexplicable by the laws of physics, right?
Except that temperature is not the same thing as heat! The Sun's surface is much, much denser than the incredibly rarified corona, so that even though the Sun's photosphere is less than 1% of the corona's temperature, it emits energy at a rate that's over 40,000 times the amount required to heat the corona up to it's high temperature. We even think we know why: the wave heating theory, where energy can be transferred over long distances from the solar interior to the corona.
Remember what temperature is: a measure of the mean speed of the particles. Similar to how two balls -- a tiny one and a very massive one -- dropped one-atop-the-other will lead the tiny ball to rocket upwards at an incredible speed, the problem isn't getting a few particles to have a very large speed. The problem also isn't unique to the Sun; if we take a look at Earth's upper atmosphere, where it gets really rarified (above 80 km), we find that it does the same thing in terms of temperature!
(Image credit: Earth's Atmosphere, from kowoma.de.)
The problem is that we associate temperature with heat in our minds, but the "very high temperature" corona contains almost no heat! But if we look in terms of heat, the Sun's photosphere contains much more than the corona; the corona merely reaches higher temperatures.
5.) When You Look Closely, Gravity Stops Making Sense.
The article laments that gravity is so mind-numbingly weak. How dare you, gravity! And it's true; weaker by something like 38 orders of magnitude than the electromagnetic force, even your puny comb can outdo the gravitational pull of the entire Earth when it comes to lifting certain objects. But this isn't a mystery, it's an empirical fact of nature!
The standard model of particles and interactions can do a whole lot, but one of the things it can't do is explain why the fundamental forces are the strength that they are. Neither can general relativity, our theory of gravity. As you can see, gravity is very, mind-numbingly weak, even compared to the weakest other force.
But whether you look close or far, at something as massive as a supermassive black hole or as tiny as a laboratory mass, general relativity still gives the correct answer to everything. The only argument that one could even make that "when you look very close, it stops making sense" would be to go down to the smallest scales we know of.
Only, with gravity, we can barely make it below the millimeter-scale before it becomes too difficult to measure. And we can measure the effects of gravitation down to these sub-millimeter scales: it obeys general relativity just fine, thank you. Perhaps someday, we'll reach down to quantum mechanical scales and find that our classical theory of gravity, general relativity, is insufficient. But in theory, general relativity is good all the way down to the quantum limit of the Universe, and we have yet to find an experiment or observation that contradicts it.
So, get this. In the 1970s, we launched two probes -- Pioneer 10 and 11 -- into the outer Solar System. As we tracked their positions over many decades, we knew exactly what to expect. After all, we know the laws of gravity, we know the masses and positions of the Sun and all the planets, and we should be able to predict the spacecrafts' motions flawlessly. Except we saw a small -- but definitely non-negligible -- acceleration back towards the Sun!
Immediately, a number of spectacular explanations arose. Gravity is wrong! The solar system is full of dark matter! Spaghetti! Except among most astrophysicists (like me), another explanation arose: maybe the asymmetric spacecraft is being heated (and is radiating) asymmetrically.
For decades, the debate raged, as much as anything where one side doesn't really give the other side much credibility can rage. And then last year, it was definitively measured that the "anomalous acceleration" is not constant, but decreasing, and hence in total agreement with the theory that it's due to the thermal effects that the astrophysicists pointed out. So yes, cracked, satellites speed up for no reason, but only if you ignore the actual reason.
3.) The Law of Conservation of Energy? More of a Suggestion, Really.
Looking at black holes, there are only a few types of hair they can have: mass, angular momentum, and electric charge. (And, if you believe in it, magnetic charge.) All of that stuff is conserved. But what about information? That's something that needs to be conserved. If I throw the Count of Monte Cristo into a black hole, it contains a different amount of information than an equal-mass book of all work and no play makes Jack a dull boy. But if energy must truly be conserved, mass, charge, and angular momentum won't take care of it! This conundrum was known as the black hole information paradox.
I said "was known" as that. Because the information isn't lost; we know exactly where it goes! When any object falls into a black hole, from its point of view, it simply passes through the event horizon and falls into the singularity, getting torn apart in spectacular fashion. But to an observer outside the event horizon? The object appears to get stretched out, fainter, and reddened, but you'll never see it cross over onto the inside. What we see, instead, is that information gets imprinted, forever and ever, onto the surface of that black hole's event horizon!
So even though you might have amazing difficulty reading it, that information from the Count of Monte Cristo is still there on the surface, even if its mass is the only thing you know from the black hole's insides.
Radioactive decay, the process that allows an unstable atomic nucleus to transmute into a different element, is one of the slowest physical processes known to man. Often taking billions of years, radioactivity is built on a foundation of quantum mechanics, where a metastable nucleus must quantum mechanically tunnel into a less energetic, more stable state.
(Image credit: retrieved from Aggeli K at BrightHub.com.)
It isn't easy, as you can imagine, because there's no good way to get up-and-over the proverbial hill; it isn't like those protons and neutrons just spontaneously align into that less energetic configuration! What you need to remember is that each of these particles that make up the nucleus are quantum mechanical in nature: they're not just particles, but they're waves, too. And waves spread out over time, where they can attempt to tunnel into that more stable (post-decay) state. Every once in a while, after enough time has passed, a nucleus will find its way into that state, and when that happens, you get a decay!
But it takes time to get there. If you're too impatient, and you can't wait, you might be tempted to look right away. Only, you know what happens in quantum mechanics when you make an observation: you collapse the wavefunction into one particular state! So if you can't help yourself from making observations, what you're basically doing is resetting the clock every time you look!
If you're cracked, you'll lament that this is like the watched teapot that never boils. While if you're a physicist, you know the teapot boils, but the nucleus won't decay unless you stop continually collapsing its wavefunction!
(Image credit: CERN neutrinos to Gran Sasso, retrieved from Universe Today.)
1.) Einstein's Theory: Relatively Full of Crap (Also? Time Travel!).
And finally, the faster-than-light neutrinos thing, again. For those of you who've been living under a rock, the OPERA experiment in a mine under Gran Sasso detected neutrinos sent from CERN, and they detected them 60 nanoseconds sooner than they would have had they moved "only" at the speed of light.
For one, we had a supernova in 1987, which raced photons and neutrinos for over 100,000 light years; were the neutrinos moving at the speed OPERA indicated, they'd have arrived four years earlier; instead, they arrived within hours. There are actually a host of other experiments that have constrained the speed of neutrinos, and if you look at all of them -- across a wide variety of energies -- you find that the new experiment, OPERA, is the one outlier, in conflict with everything else.
The OPERA results are bizarre enough that experiments in the United States and Japan are being set up right now to either verify or refute them. When it comes to this story, I've been doingmybesttoinformtheworld, and I'll stay on top of it and keep reporting all the latest developments that come up, too. But for right now, it's going to take some extraordinary evidence before I'm ready to chuck special relativity, even for something as mundane as the neutrino.
And there you have it: six scientific discoveries that might appear to laugh in the face of physics, but only until you learn the physics behind it! Isn't information beautiful?
"You cannot hope to build a better world without improving individuals. We all must work for our own improvement, and at the same time share a general responsibility for all humanity." -Marie Curie
Most of us remember the importance of being charitable on a few rare occasions throughout the year, most commonly around the year's end. But what about the rest of the year? Obviously, we don't have an unlimited amount of resources, so for most of us, it's not a viable option to do as Magnolia Electric Company suggests, and
But what if I told you there was a way to donate to charity, help advance science, and give yourself a chance to win a nice sum of money, at really no cost to you?
May I present to you The Charity Engine, the best supercomputing project I've ever heard of. You might have heard of individual projects like Einstein@Home, which has found 16 pulsars since its inception, or SETI@Home, which sifted through telescope data for signals of extraterrestrial intelligence. Both of these relied on sending unprocessed data to individual computers all across the internet, having users donate their spare processor time to doing these computations, and sending the finished work back to the server. This basic idea -- borne from the Berkeley Open Infrastructure for Network Computing -- is the core of the Charity Engine.
But the Charity Engine goes far beyond any of these projects. Let's say you've got an enormous computing job and not enough computing power to do it. I don't care whether you're a scientist, a University, or an independent company, where do you go? Enter the Charity Engine!
Charity Engine takes enormous, expensive computing jobs and chops them into 1000s of small pieces, each simple enough for a home PC to work on as a background task. Once each PC has finished its part of the puzzle, it sends back the correct answer and earns some money for charity - and for the prize fund. (It also earns more chances to win.)
Where does the money come from? Science and industry. The grid is rented like a giant supercomputer, then all the profits shared 50-50 between the charities and the lucky prize winners.
Charity Engine typically adds less than 10 cents per day to a PC's energy costs and can generate $10-$20 for charity - and the prize draws - for each $1 of electricity consumed.
It is the most efficient way to donate to charity ever invented.
You can follow them on facebook and twitter, and by joining, you can become part of what they're hoping will become the world's fastest supercomputer within a single year! For each additional dollar (or pound, or euro) you spend on electricity on this application, you generate about twenty times as much for the Charity Engine, which gets split, 50/50, between their charities and their users. (That's you!) And you never have to think about it; it only uses your CPU's idle time, and turns itself back off as soon as you try to use your machine again! (The worst thing it does is make itself your screensaver and require a restart after installation.)
Best of all, you've got a great reason to support them: they come certified by Starts With A Bang! Let's say you want to, I don't know, simulate the formation of a galaxy -- from scratch -- in the Universe?
You and hundreds of other people, right? Who decides whose project is worthy of the Charity Engine's power? They'd need some kind of expert to help them decide, right?
There's an entire science panel, and yours truly sits on it, to help decide which projects get the 5-10% of the grid permanently reserved for pure science! So you're not just supporting charity, you're supporting legitimate science, hand-picked by me and the rest of the science panel! (Plus, their CEO is a huge fan of this blog, so you know there's good taste involved here!)
Read more about them at crunchbase, Fast Company, and one of Charity Engine's charity partners, OxFam. This is a great opportunity for everyone to support science, help charity, and -- for those of you who feel lucky -- maybe win a small fortune while you're at it. How can you not feel good about this; get started and help make something wonderful happen today!
"The diversity of the phenomena of nature is so great, and the treasures hidden in the heavens so rich, precisely in order that the human mind shall never be lacking in fresh nourishment." -Johannes Kepler
So said the man who, in 1604, discovered the supernova that was the last to be seen, visually, within our own galaxy. Although it's likely that two others occurred subsequently, they were not visible to human eyes, and only with powerful telescopes were their remnants discovered.
But earlier this week, the first supernova of the year was discovered, in a galaxy 25 million light years away, NGC 3239. The supernova, indicated below, is now known as SN 2012a.
Remember, now, there are two ways we can have a supernova, but both ways involve a runaway nuclear fusion reaction, giving off a tremendous amount of light and energy. But most of the energy, perhaps surprisingly, isn't in the form of light! Let's take you inside a star that goes supernova during those critical few seconds.
Although there are shocks and heat that are produced, you'll see that the interior reactions produce neutrinos, nearly all of which do not interact with the outer layers of the star! A few of them do, as do all of the protons, neutrons and electrons produced, and the overall production isn't instantaneous. But while it takes some time -- a couple of hours -- for the shock to reach the outer surface of the dying star, the neutrinos make it out almost immediately!
What this means is that when we have a star go supernova, neutrinos get emitted from it before the light does! We actually discovered this, firsthand, back in 1987.
(Image credit: NASA, ESA, R. Kirshner and P. Challis.)
When supernova 1987a went off just 168,000 light years away, it was close enough -- and we had enough neutrino detectors operating -- that we detected 23 (anti)neutrinos over a timespan of about 13 seconds. The largest detector, Kamiokande-II, contained 3,000 tons of water and detected 11 antineutrinos.
Today, the detector that sits in the same spot, Super Kamiokande-III, contains 50,000 tons of water and contains over 11,000 photomultiplier tubes. (There are many other excellent neutrino detectors around the world, but I'm focusing on this one in particular as an example.)
(Image credit: Kamioka Observatory, ICRR, The University of Tokyo.)
This setup is so amazing because it can not only detect neutrinos, but it can reconstruct the direction, energy, and point-of-interaction of even a single neutrino fortunate enough to interact with any one particle in those 50,000 tons of water!
Depending on where a potential supernova goes off in our galaxy, we would expect Super Kamiokande-III to see anywhere from a few thousand antineutrinos (for something on the other side of the galaxy) to over ten million of them, all in the timespan of just 10-15 seconds!
Neutrino detectors from all over the world would see a flood of detections like this, all at the same time, all coming from the same direction. At that point, we'd have something on the order of two-to-three hours to identify the direction of origin of those neutrinos, and point our telescopes towards that direction to try and obtain an optical view of the supernova -- for the very first time -- from its very beginning!
Even so, we didn't get to first observe this one, SN 2002ap, until 3-4 hours after first ignition. If the supernova that eventually comes is a type Ia supernova -- which originates from a white dwarf -- we have no way of predicting where in the galaxy that will occur. White dwarfs are simply too abundant, and the locations of almost all of them are simply unknown, and thought to be distributed all over the galaxy.
But if this originates from a very massive star whose core collapses under its own gravity (i.e., a type II supernova), we have a number of really good candidates, and some outstanding places to look.
Most obvious is the galactic center, the location of the Milky Way's last known supernova, and also the location of the most massive stars ever discovered within our galaxy. We're certainly going to have many type II supernovae originating here over the next 100,000 years, but we have no way of knowing when we'll see the next one. As you look at the above picture, take a moment to appreciate that it's very likely already happened, and we're just waiting for the neutrinos (and then the light) to get here!
But there are closer candidates than the galactic center.
(Image credit: T. A. Rector & B. A. Wolpa, NOAO, AURA, retrieved here.)
Look inside one of the great, star forming nebulae in our galaxy, and you're going to find some of the hottest, youngest stars you're going to find anywhere in the Universe. This is where the ultra-massive stars live, and in particular, the Eagle Nebula, above, may be home to an extremely recent supernova. The Eagle Nebula, the Orion Nebula, and many other regions filled with new stars are all great places to anticipate the next supernova.
But what about known, individual stars? While there are many good candidates, we have two in particualr that we can't help but talk about.
Eta Carinae, in the very last stages of its life, could literally go supernova at any second. But it may also live hundreds, thousands, or even tens of thousands more years before it does so. Still, if we get a flood of antineutrinos originating from anywhere near its position in space, this will be the very first place we point our telescopes!
But unlike all of these candidates that are many thousands of light-years away, we have one good one that's much closer. In fact, it's the closest supernova candidate we have!
(Image credit: A. Dupree, NASA.)
Say hello to Betelgeuse, a red supergiant just 640 light-years distant. Betelgeuse is so gigantic that it literally is the diameter of Saturn's orbit around the Sun! If Betelgeuse went supernova, our neutrino detectors around the globe would detect -- all told -- somewhere in the vicinity of a hundred million (anti)neutrinos, which is more neutrinos of any type than have ever been detected in the history of the world, combined.
But unless it's one of these known candidates that goes supernova, how will we tell whether it's a type Ia or a type II supernova?
We can always wait, I suppose. Supernovae of different types have very distinct light-curves, and how the light dies off after it's reached its peak brightness will tell us what type of supernova we had.
But if something this exciting happens, I'm not going to have that kind of patience. Luckily, I won't need it, because a supernova within our galaxy would likely be the very first detectable observation for the newest type of astronomy: Gravitational-Wave Astronomy!
Undisturbed by the presence of, well, anything, gravitational waves from a supernova explosion should pass through the intervening star, any gas, dust, or matter completely undisturbed, arriving at the same time the front end of the (anti)neutrino pulse arrives! The wonderful thing is that -- according to our best simulations of general relativity -- type II (core-collapse) and type Ia (inspiraling white dwarfs) should give vast different signals for gravitational waves!
If we have a type Ia supernova, we expect to see three separate regions to our signal.
The inspiral phase should give a periodic pulse that increases in frequency and magnitude as the white dwarfs reach their final stage of their separation. As the ignition occurs, there should be a spike in the signal, followed by a "ringdown" phase as the ripples go away. Very distinctive.
But if we have a type II supernova, from a super-massive collapsing star, we're only going to see two interesting things.
Just a huge spike -- where the supernova itself occurs -- just a tenth of a second after the core collapses, followed by a very rapidly dying (within 0.02 seconds) ringdown. And so if we want to know what we saw, all we need to do is extract the telltale signal from gravitational waves!
And if the galaxy's next supernova were to happen today, this is what we'd see!
"Events are the ephemera of history; they pass across its stage like fireflies, hardly glimpsed before they settle back into darkness and as often as not into oblivion. Every event, however brief, has to be sure a contribution to make, lights up some dark corner or even some wide vista of history... illumined by the intermittent flare of the event." -Fernand Braudel
The spectacular event of the day, however, isn't something that started on Earth. Rather, 93 million miles away, it was our Sun, early yesterday morning (about 38 hours ago as I write this), that had a brief... shall we say... outburst. NASA's Solar Dynamics Observatory got the best view of this event as it happened, looking in extreme ultraviolet (13.1 nanometer) light, and collapsed the one-hour flare into a meager seven seconds.
Why's that? Because Solar Flares are often accompanied by Coronal Mass Ejections (CMEs), as shown above in this 2002 SOHO image.
So what's so special about yesterday's Solar Flare?
(Image credit: NASA/SDO and the AIA consortium. Edited by J. Major, retrieved here.)
This Solar Flare produced a CME directed towards Earth, and since it's moving at around a whopping 1,000 miles per second, that means it's arriving... right around... NOW!
That's right, the largest solar storm since 2005 is going to hit Earth today/tonight, particularly right at the edge of the Northern Hemisphere! Here are a bunch of time-lapse views of the flare from the Sun from a number of different satellites, courtesy of space.com.
As you can see from the blue video (NASA's SOHO Satellite), there was a coronal mass ejection, followed by intense speckling on the satellite. (Did you notice that?) It turns out that that is the reason we really care about this!
A coronal mass ejection is when this heated plasma stream of electrons, protons, and heavy ions gets launched out of the Sun in a random direction in space. This charged radiation can totally do some damage to electronics; that's what the speckling you saw was! (There's a nice explanation and video by Phil, here.) What about you, you may ask?
You are fine. Know why? Because of this.
(Image credit: NASA/Goddard Space Flight Center, retrieved from SWRI.)
The Earth's magnetosphere protects us from this radiation! The magnetosphere bends the charged particles that would strike most regions of the Earth away from the equatorial regions, and funnels them only around the polar areas. As the particles come down towards Earth, they interact with the atmosphere, which does an excellent job of stopping them before they ever make it to the surface. In fact, this particular CME will mostly miss the Earth (remember, Earth is tiny on the scale of the Solar System), flying over the North Pole. Still, our magnetic field will bend some of these charged particles into the Earth's atmosphere! Know what that produces?
The Aurora Borealis, or the Northern Lights! (If the flare had been below the South Pole, we'd have gotten the Southern Lights, or Aurora Australis, instead.) Anyone with clear skies in the Northern Hemisphere should go and look for them tonight; we don't know how far South they'll be visible, but even places that very rarely get aurorae might be in luck tonight!
Astronauts on board the International Space Station! You might be worried that the astronauts on board would not be shielded by the magnetosphere, and so would be in grave danger from a coronal mass ejection like this. After all, at 240 miles above the surface, there's no atmosphere to protect them by absorbing all the protons, ions and electrons!
So what does that mean; do the astronauts absorb this radiation directly?
No, the ISS has a hull designed to shield them from this type of radiation. As this Universe Today article details, everyone and everything on board the ISS will be totally safe. In fact, any well-designed satellite will have shielding against the radiation from CMEs; the only pitfall is that most of them -- including GPS satellites -- were built cheaply, and don't have this type of shielding. That's the only type of danger from a flare / CME like this.
Yes, it's true that tremendous solar storms can be problematic, particularly for large power lines, plants, and grids, but this is not that storm. But the coming aurorae?
"I want more muscles! I go to the gym three or four times a week with a personal trainer. I can afford that now. I can't put on weight though, no matter how much I eat." -Christopher Parker
Many of us struggle in all sorts of aspects of our lives: to balance work and leisure, friends and family, responsibility and fun. For nearly all of us, something eventually goes awry, and when it does, we suddenly can't meet all our commitments at once. Regardless of where you come from or what you like, this is a problem we all have to face at some time or another. For this week, I'd like to introduce you to Gangstagrass, a bluegrass-hip-hop band, which are honestly two genres I never thought I'd hear combined. Not only have they done so, they've done so phenomenally well, as you can hear by their song,
I've always been someone who's prioritized taking care of myself, physically, as those of you who've hung around here for some time have likely noticed. But this past April, I gave myself a nasty injury, and found that I needed to take some time off from intense physical activity to heal. (It happens.) And while I've come to adopt relatively healthy eating habits, I started noticing the inevitable... well, you know.
You start using the larger holes on your belts, you start asking yourself if you can have that dessert you've had your eye on, and you start trying to cut down on portion sizes, you avoid eating later in the day, and you even go back to counting calories.
And, if you're anything like me, you combine that reduced activity level with a calorie-restricted diet, you start feeling like crap. There are a whole bunch of different diets out there and a whole bunch of people and organizations -- including the USDA -- telling you what you should eat to be healthy. And, if you're anything like me, what you'd really want is the actual, scientific information as to how nutrition, your body, your diet, and fat gain/loss work.
And it just so happens that a couple of months ago, I got an email from Jonathan Bailor, asking me if I cared for an advance copy of his new book.
His book is called, "The Smarter Science of Slim," and it does what no other diet, weight-loss, or fitness book I've ever seen does: it explains the biological workings of your body's metabolism. The first three sections of the book -- and it has seven sections -- are the most valuable book on diet and health I've ever read for the clearly presented, well-articulated and comprehensive information provided inside. Along the way, a lot of myths about food are busted, including the most common one: that restricting your calories and upping your exercise is a solid plan for losing weight, particularly in the long term.
It turns out, unsurprisingly, that people like Christopher Parker, atop (you know, "I can eat whatever I want, my metabolism just burns it up"), are real. But it also turns out that, to a much greater degree than we normally think about, what we eat helps determine our metabolism. I'm going to give you the most basic redux of how your metabolism works:
You get hungry, and so you eat some food that contains some non-zero amount of calories.
Your body produces some amount of insulin, which helps deal with the sugars and starches in the food, and moves them into your cells where they're stored as fat.
When your cells get the signal that the nutrition they need is coming in, your body produces leptin (only discovered in 1994!), which is the hormone that tells your body that you're full, and gives you the feeling that your hunger is satiated.
So if you want to eat healthy, you want to eat foods that don't aggressively spike your insulin, that do stimulate that feeling of satiety, and, of course, that properly provide the nutrients your body needs. Through a very clear presentation (two sample pages are shown below), this book tells you exactly what types of foods you should base your diet around (and what foods you should avoid) if you want to eat healthy, according to your body's metabolism. He develops his own index for determining which foods you should and shouldn't eat, and while the acronym (SANE) isn't the easiest to remember, learning what is good for your body vs. what's not good becomes very clear very quickly.
You'll find aspects of a number of popular diets in here, including the Atkins diet, the Paleo diet, and the Sugarbusters diet. But -- for me, at least -- the takeaway message was this:
Eat meals that are high in fiber, high in protein, and low in both sugars and starches. (That means your good "friends," complex carbohydrates, are not your friends at all!)
Ideally, you'll get between 30% and 40% of your calories from protein. While this may sound like a "high-protein" diet to you, this is actually (according to your body) the amount you want for a balanced diet! (And no, you won't start seeing liver or kidney problems until that number gets up above something like 60%!)
As far as foods go, you should be eating vegetables as the base of your food pyramid (or as 50% of your plate). Lean proteins (like fish, chicken, lean red meat, egg whites, etc.) should be the next most common, followed by fruits, nuts, and legumes.
Eating too much fat is bad, but so is eating too much sugar or starch. Whole fruits are not bad, so long as you're eating the vegetables and lean proteins that you should be eating. Fiber-free juices and sodas are what you want to avoid!
Over the past couple of months, I've worked to incorporate these changes into my diet, to just make this part of the way I live. It's fortunate for me that I like cooking, and that I have access to some pretty amazing ingredients (and a couple of pretty amazing farmers who supply me with all sorts of vegetables year-round) at my disposal. My meals have gotten a lot healthier, I feel a lot better, and my clothes are fitting better, too. In fact, here's one of yesterday's pictures from the 2012 West Coast Beard & Mustache Championships:
(Image credit: Plutarco Calles. I took 2nd place in the Partial Beard category!)
Learning how your body deals with food and how the different types of calories and nutrients you put into it makes me strongly recommend The Smarter Science of Slim for anyone looking to improve their diet and learn how what you eat affects how your body reacts to it. The fourth and fifth sections -- about the US Government and Corporate influence -- are only okay, and the sixth and seventh sections read like a personal diet and exercise guide, which were a little bit of a turn-off to me. But the solid science of the first three sections, which were the meatiest part of this book, definitely are worth it for anyone who wants to adopt a positive, healthy-eating lifestyle for the rest of their lives!
Now, if you'll excuse me, I've got a delicious, healthy dinner to cook...
"When I had satisfied myself that no star of that kind had ever shone before, I was led into such perplexity by the unbelievability of the thing that I began to doubt the faith of my own eyes." -Tycho Brahe
When we look out at galaxies throughout the Universe, we find that every so often -- about once per century -- a bright star flares up so brightly that it can, for a brief amount of time, outshine the entire rest of the galaxy!
What's going on, of course, is not that a star is brightening, but that the very atoms composing a star are undergoing a runaway chain reaction of nuclear fusion, creating the infamous phenomenon known as a supernova!
In perhaps one of the worst strokes of luck, we haven't seen a supernova go off in our own galaxy since the invention of the telescope! The last one, in fact, went off in 1604, and has long since faded from view. But thankfully, it isn't just in visible light that we can learn about these objects: we can turn a myriad of telescopes sensitive to different wavelengths at the regions of sky where these supernovae were recorded, and see what they look like today!
The 1604 supernova was the last one visible from Earth with a human's naked eye, and is shown here in a composite of visible light, X-rays, and infrared. We know, from the lack of a strong X-ray source (neutron star or black hole) at the center, that this explosion was probably a Type Ia, where a white dwarf star either merges or accrues enough matter and goes supernova!
Visually unspectacular, the ultra-hot remnants of the exploded star have been blown off into space at breakneck speeds of thousands of kilometers per second, and are so hot that they emit X-rays! There's also dust, present throughout the galaxy, which gets heated by the supernova explosion; that's what glows in the infrared.
The last supernova before that? You have to go all the way back to 1181, and we still aren't sure we found the remnant from that. But we've definitely found the one observed prior to that: SN 1054.
This supernova remnant, as you will immediately notice, looks nothing like the prior two, and for a good reason: it's an entirely different type of supernova! The famed Crab Nebula, also known as Messier 1, wasn't formed by a white dwarf getting too massive, but rather by an ultra-massive star burning through all of its nuclear fuel and dying in a core collapse supernova, blowing off tens of solar masses worth of material!
The collapsed core of this star has created a pulsar, one of the most spectacular clocks in the Universe, and bested for timekeeping purposes only by our atomic clocks on Earth!
Prior to that, there was the brightest supernova ever recorded on Earth: the one of 1006.
(Image credit: Chandra, Hubble, and NRAO teams, retrieved here.)
By this point, you should be able to tell that this was once a white dwarf and not a supermassive star, and you'd be correct! After 1,000 years, the "bubble" produced by this explosion is actually light years in size, and if it were our star that exploded like this, the edge of the bubble would be halfway to Alpha Centauri by now!
Prior to 1006? There was one in 393 that we may have found, one claimed to have been found in 386 that probably wasn't, and the oldest supernova ever recorded (and verified): Supernova 185!
Again, just from looking at the X-ray image, 2000 years later, you can tell this was a white dwarf that exploded, and not an ultra-massive star.
But looking at these images got me curious: how much fun would it be to take a look at these supernova remnants in visible light only, like watching snapshots from a slow-motion cosmic fireworks show? Let's go to the pictures!
From nearly 2000 years ago, the supernova remnant RCW 86 (from the 185 supernova) still has a small section of the outer "bubble" visible in visible light, as shown in red, above. Like the very end stages of a fireworks display, this is the last bit that would be visible with unmodified human eyes. (The blue is shocked X-ray gas.)
But apparently, a thousand years doesn't necessarily change things all that much.
The 1006 supernova is nearly invisible in optical light, save for a thin ribbon and some very faint gas along the outer shell. (And, of course, all the stars visible in the image, too!) But the 1054 supernova, the only one we talked about as being a remnant from a supermassive star instead of from a degenerate white dwarf (that's not a snark; they really are degenerate), has an entirely different story to tell.
(Image credit: High Energy Focusing Telescope (HEFT), NASA, retrieved here.)
That gorgeous image of the Crab Nebula I showed you earlier? That was entirely a visible light image! The outer layers of gas, rich in some of the lighter heavy elements -- oxygen, carbon, nitrogen -- create some beautiful, contrasting colors in the nebula as they get superheated and strewn across interstellar space.
But there's a very rich story to be told in a myriad of wavelengths, as you can clearly see, from the bright X-ray source at the core to the warm dust traced out by the infrared telescopes. Visible light still tells a rich story for the Crab Nebula because of the sheer amount of gas and dust, as well as the energy that was released into it.
The 1572 supernova, with almost no gas and dust, tells a very different story.
Sure, they found the leftover, Sun-like star that got blasted by its companion which went supernova nearly 500 years ago, but visible fireworks? Not a trace.
So there's some variety here, and this is well-exemplified by the 1604 supernova.
Not a bubble or a ribbon, but just a small region of the remnant contains some visibly glowing gas.
It seems like the one thing that's missing -- that I'd want to know about, anyway -- is a supermassive explosion where that hot, visible dust were somehow stripped away. What would that look like?
Well, there weren't any naked-eye supernova that have occurred in our galaxy since 1604, unfortunately. But in the late 17th Century, there was a supernova that occurred, and while its remnant is very faint optically, it's the loudest radio source (right, Nicole?) in our galaxy: Cassiopeia A!)
(Image credit: as above, retrieved from a great Cas A database, here.)
Located an estimated 11,000 light years away, this supernova remnant is already over 10 light years across, making it larger than the Crab Nebula in just a third of the time! With the strongest radio source (other than the Sun) in our galaxy, there must be either a fantastic neutron star or black hole at the center.
But today, I wanted to show you the fireworks.
(Video credit: ESA/Hubble (M. Kornmesser & L. L. Christensen), retrieved from YouTube.)
Not from a simulation or visualization, though. The incomparable Hubble Space Telescope has an amazing, long-exposure photograph of the visible light left behind from this supernova explosion, which you have got to see, because it truly shows you why I call these explosions "cosmic fireworks."
This is fantastic! If you have all day, I suggest you play around with the full, amazing-resolution version. I did, and so I decided to make it a little more interesting for you, by zooming in, bit-by-bit, to one of the most interesting spindly regions inside this amazing stellar show.
Let's focus first on the bubble.
And now let's take a look at the triple-layered structure atop that bubble. Look for little "columns" or "pillars" where some regions of space have greater densities of gas and/or dust than others.
And finally, let's zoom in to focus on that green region you see.
As always, click on any of the images on this page to get the fullest-resolution version available, and I hope you enjoyed the fireworks show! It's been far too many centuries since the last visible supernova in our galaxy; will we get one in our lifetime? As the Count of Monte Cristo concludes:
all human wisdom in contained in these two words: wait and hope.
"We find them smaller and fainter, in constantly increasing numbers, and we know that we are reaching into space, farther and farther, until, with the faintest nebulae that can be detected with the greatest telescopes, we arrive at the frontier of the known Universe." -Edwin Hubble
While large parts of the internet are blacked out today, in protest of SOPA and PIPA, I could think of no better way to highlight the importance of free exchange of information on the internet than by showcasing one of the most interesting, varied and intricate objects in the entire galaxy: Messier 16, better known as the Eagle Nebula. It's been imaged by literally thousands of different telescopes and instruments, and it's only through the free, public exchange of that information that we've been able to learn as much about this beautiful object as we have. Let's get right to it!
A good-sized amateur telescope, looking up at the Eagle Nebula under excellent seeing condition, will see this vast, dusty expanse of glowing red gas amidst a field of hot, blue stars. The red color teaches us about the hydrogen atoms present, while the darker features within the nebula indicate very dense clouds of gas and dust. This is where new stars are suspected to be forming, but we can't know for sure simply by looking like this.
The very same visible light that allows us to see this intricate structure is the same set of wavelengths that the interstellar dust is very good at absorbing, even with the Hubble Space Telescope!
Very much like the region where our own Sun was born 4.5 billion years ago, these "Pillars of Creation" contain, at the very borders, a large number of evaporating gaseous globules. The light-absorbing dust here is not only where newborn stars are being creating, but these stars are actually in the final stages of growth, as soon the cold gas that can create new stars will be either used up or blasted away.
The false-color showcases the different gaseous compositions of different regions of the cloud (focusing on Oxygen, Hydrogen and Sulfur), but still cannot show us exactly where the vast majority of these ultra-hot, newly formed stars are. But if we can look with a different wavelength of light, sensitive to these stars but insensitive to the intervening dust, we could find out where those stars are.
The Chandra X-ray Observatory, a space-based X-ray telescope, is sensitive to such wavelengths! There are lots of things that emit X-rays: supernova, black holes and neutron stars, as well as hot, ultra-massive newborn stars! It turns out that the evaporating gaseous globules themselves do not contain X-ray emitting stars; in fact most of the X-ray sources are not even in the pillars themselves.
Interesting! But we can learn even more about what is present inside these pillars by looking at still different wavelengths of light. For example, the 8.2 meter Very Large Telescope has taken a look at these pillars in the near-Infrared. What did it find?
Most (but not all) of these evaporating gaseous globules do not contain stars at all, and of the ones that do, pretty much all of the stars in there are less massive (and cooler) than our Sun is!
But looking in the near-infrared can only reveal so much, and leads to even more questions. Are there even less massive stars in there than the VLT can detect? Do each of these globules contain a star (or multiple stars), or are some of them truly sterile? And what came first, these globules or the stars that are inside of them? We tried looking with the ESA's Infrared Space Observatory,
but it didn't have sufficient resolution to teach us anything beyond what we already knew. But just yesterday, the Herschel Space Observatory released an image of the Eagle Nebula that probed deep into the far Infrared, where the hottest (blue) regions represent a temperature of just 40 Kelvin, while the coldest (red) regions are merely 10 Kelvin above absolute zero. Take a look for yourself!
This wide-field image of the Eagle Nebula shows that there's plenty of cool gas still there to form stars even in the hottest regions, but it also shows that the pillars themselves are the hottest regions with the least amount of ultra-cold gas. Yes, the other regions of the nebula are far cooler, and you can clearly see that the interior region looks like a partially carved-out pumpkin, devoid of any cold gas. Know what we think would drive that cold gas away, by heating it up?
A recent supernova. And -- if you remember from earlier -- supernovae would leave a signature in the X-ray. Let's take a wide-field look with the best X-ray telescope in space today: XMM-Newton.
In this image, the red colors are the coldest and the blue are the hottest, with temperatures ranging from only a few million Kelvin up to, for the brightest, darkest blues, around 90 million Kelvin. Let's overlay the XMM-Newton and Herschel images atop one another and see how this stacks up.
Could there have been a recent supernova at the center? To be honest, they don't know, yet! What you'd look for is faint and diffuse X-ray emission, and you'd see how far it extends around the interior regions of the nebula. If XMM-Newton sees too much of it, it would invalidate this theory, but a small (but non-zero) amount would support it. The work is still being done, but this is the current working theory, and it's consistent with what Chandra (X-ray) and Spitzer (infrared) have seen in their previous observations.
Still wondering about the pillars themselves, and if there are stars forming at the edges there? Let's take a look deep inside the pillars themselves, to the maximum resolution that Herschel can achieve.
Those edge regions, where the evaporating gaseous globules are located, are definitely where the hottest portions of the cold gas are, further evidence that this is where the evaporation is occurring. But although there are some stars inside those globules, are they providing the heat that's causing the evaporation? Or are they simply being formed in regions that are evaporating for entirely unrelated reasons? I wish I had the answer!
It's clear that the pillars are evaporating, but whether there are necessarily stars, proto-stars or any other interior heat source heating up these globules, or if it was a recent cataclysmic release of energy (i.e., from a supernova) nearby is unclear. Where does that leave us? At the edge of our knowledge, where we're pushing the limits of what we currently understand; welcome! There's a wonderful composite image over at Universe Today showcasing all the different data sets, but I prefer this ESA video to illustrate just how remarkable the Eagle Nebula is, looked at with a myriad of different instruments and telescopes.
It's also important to realize that I, personally, have no claim to any of these images, telescopes, or missions. The only reason I can bring you these images, this video, this story and this information is because the entire community of astronomers, astrophysicists and physicists have decided to make all of this information public, and that it should be public. It's not only for the people who work on it, who discover it, or who pay for it; it's for everyone. So share this information -- and all the information about the Universe that we learn from here on out -- with everyone who wants to know it. It's your Universe, too, and we all have a right to it.
"This is to show the world that I can paint like Titian: [See drawing, above.] Only technical details are missing." -Wolfgang Pauli
First theorized by Pauli all the way back in 1930, neutrinos are some of the most mysterious and puzzling particles ever discovered in nature. For starters, they weren't even first detected until 1956 (by Reines and Cowan), 26 years after they were predicted to exist! Coming in three flavors -- electron, muon and tau -- and in both particle and anti-particle type, these neutrinos have the smallest but non-zero masses of any particle ever discovered.
The history of these elusive particles is literally a treasure trove of riches into the fundamental nature of our physical world. The picture above -- the very first of a neutrino in a hydrogen bubble chamber -- is a fantastic example. Over to the right of the image, you can see what looks like a bunch of tracks all originating at some vertex.
This image -- generated in 1970 -- is a surefire sign of a neutrino striking a proton, something we can definitively tell by the tracks of the particles coming off. (None of which, by the way, is a neutrino!)
(Image credit: Argonne again, retrieved from Universe Today, and corrected by me.)
Based on the curvature and radii of the tracks left by the particles that come out of this interaction, since they're all in a known magnetic field, we can determine their masses, charges, and velocities, and hence we can reconstruct that this was a muon neutrino that struck a proton, producing a negatively-charged muon (to conserve lepton and lepton family number), an oppositely-charged pion (to conserve electric charge) and kicking the proton off (to the upper right)! You can tell the charge of any particular particle by the direction it curves in the magnetic field: positive ones curve counterclockwise, negative ones curve clockwise!
Neutrinos are incredibly difficult to detect: we need to literally make quadrillions of them at the highest energies achievable just to have a reasonable chance at detecting one neutrino, and the lower in energy your neutrinos are, the more steeply their cross-section drops, as the graph below shows.
And, as you all know, recently a beam of very high-energy neutrinos was sent from CERN to Gran Sasso. Something remarkable like 1020 neutrinos were generated and launched towards the OPERA detector, hundreds of miles away beneath an Italian mountain, and a few thousand of them were detected. Oddly enough, on average, they were detected about 60 nanoseconds too early, resulting in rampant speculation that these neutrinos were traveling faster than the speed of light!
I wrote a largenumberofarticlesaboutthis, and even went on TV to talk about it. Most recently, I was invited to be a guest on the radio to talk about these fascinating particles (episode available here), and as is often the case, didn't get a chance to answer everyone's questions.
Well, the skeptics over at Skeptically Speaking were kind enough to send me the unanswered questions, and I'm pleased to take them all on here for you! Let's get to it...
(Image credit: Boeing, retrieved from Inside GNSS.)
1.) Early on there was an initial response that this result had been explained because of a measuring error involving special relativity and GPS. What was this criticism and do we know yet if the OPERA team had accounted for this during their initial experiments?
It's better to start by reminding you what a GPS satellite is: it's basically a satellite in space a known distance away from the surface of the Earth, with an atomic clock on board. You take an atomic clock at your location on Earth, and you can tell what the light-travel-time (and hence the distance) from your location to the satellite is. By taking a number of GPS satellites (usually four), you can precisely know your position and the amount of time that's elapsed from any particular event on Earth. But you need to be smart about it: both the effects of special relativity (how quickly the satellites and you, on Earth, are moving as the Earth rotates on its axis and revolves around the Sun) and general relativity (the gravitational effects of the Solar System) must be taken into account! If such effects weren't taken into account, a GPS satellite could botch your position by as much as 30 meters.
How long does it take light to travel 30 meters? 100 nanoseconds. So it's conceivable that this systematic, 60 nanosecond shift is entirely due to a GPS error. However, this is well-known physics, so it's pretty reasonable to assume that the OPERA scientists know how to account for this. (Quite honestly, it would be shocking if this were where the error lied.) But, as they didn't release this information publicly, the only way to check is to have a different team do the experiment over.
2.) Are the extra dimensions theorized as part of string theory a possible part of the explanation for these neutrinos?
Although this is one of people's favorite areas of speculation, the answer is "probably not." Sure, a journey through an extra-dimension could provide a short-cut through our Universe's spacetime, shaving off those 60 nanoseconds easily. But if those extra dimensions were accessible at these relatively low energies that the OPERA neutrinos have, we would have seen see lots of other telltale phenomena at both the LHC and at Fermilab. The fact that what we've seen at both places agrees so strongly with the simple Standard Model and nothing more -- no SUSY, no Extra Dimensions, etc. -- tell us that string theory is probably not playing a role in this experiment.
3.) When the paper was first announced, information about this neutrino experiment was everywhere, and now I have to search to find up to date information about the status of these experiments and the science community's reaction to it. Why isn't the media continuing to cover this story?
The science community is -- rightfully -- skeptical of these results. If they hold up to repeat, follow-up experiments at other locations, such as MINOS in Minnesota and K2K in Japan, this will be very big news. But we've learned all we can learn from OPERA. They see neutrinos arriving 60 nanoseconds early in their detectors, they've been unable to find an error, and other experiments find that OPERA's results, when combined with other predictions of the Standard Model, do not correctly predict what they see. So either OPERA's results are wrong or our current theories about how particles and fields work are wrong when applied to OPERA's neutrinos. If we want to learn more, we need to do something new to find it out, and that's why the media coverage has dropped off.
(Image credit: Origin unknown; retrieved from Paranormal Spy.)
4.) When the news first broke on the possibility of faster than light neutrinos there was also a lot of talk about the associated possibility of time travel. What do faster than light neutrinos have to do with the theories around time travel?
It's a simple matter of economics: it's cheaper to build the OPERA experiment than it is to perform the annual maintenance on a DeLorean DMC-12.
No, no, I'm kidding. Special relativity tells you that the laws of physics should be the same in all inertial (non-accelerating) reference frames. So if I send a signal from point A to point B, then all observers, no matter where they are, in what direction or how quickly they're moving, will see that the signal was sent from point A before they see the signal arrive at point B. And this is true, so long as the signal moves at or below the speed of light.
But if that signal moves faster than light -- i.e., if the neutrinos arrived at the OPERA detector before a photon moving at the speed-of-light-in-vacuum would have -- then some observers would see that signal arrive at point B before they see you send it from point A. Hence the joke,
We don't allow faster-than-light neutrinos in here, said the bartender. A neutrino walks into a bar.
5.) What was the result of the experiment's initial purpose, to test if one kind of neutrino could turn into another kind, and what are the implications of that result? Could these two different results be related in any way?
There are three types of neutrinos -- electron, muon, and tau -- but they all have, and this is very important, the same quantum numbers. Same charge, same lepton number, same baryon number, same spin, same isospin, and almost the same mass. (A little more background on neutrinos here and here.) The way it works in quantum mechanics is that if you have the same quantum numbers, you mix together. So there might be three distinct masses for the things that make neutrinos, and we'll give them some clever names, like m1, m2 and m3. (Technically, we call these mass eigenstates.)
What we see as an electron neutrino might be 70% m1, 20% m2 and 10% m3, while the muon and tau neutrinos would have different percentages. Mixing is something that's well known to happen for the weak interactions in both quarks and neutrinos, but it's been much more difficult to measure for neutrinos than it is for quarks. So that was the original goal of this experiment: the measurement of neutrino oscillations was designed to measure exactly how neutrinos (and anti-neutrinos) do their mixing with one another.
6.) How can neutrinos oscillate when they have different masses?
So this is actually really interesting: the way that they oscillate between electron, muon, and tau types allows us to determine what the mass differences are between the different types! (Technically, the mass-squared differences.) By measuring the way the different oscillations take place, we can also tell whether there are only three fundamental types of neutrino (there must be at least three) or more than three: a fourth type would mean there must be sterile neutrinos, or a neutrino beyond what the Standard Model predicts! In other words, we were looking for new physics in this arena when we (may have) found it in another.
7.) Where do the neutrinos that miss the detector end up?
First off, this is almost all of the neutrinos. A little math: we generated about 1020 neutrinos in the OPERA experiment, and about 16,000 of them were caught by the detector, which is 20 meters long on its longest side. So if we wanted to catch half of these neutrinos, we would need about 5 x 1019 of them to interact. Assuming we just stacked identical copies of OPERA, one-after-another, until half of the neutrinos interacted, know how many we'd need?
3,000,000,000,000,000 of them! Or, for those of you who'd rather have one giant detector, you'd need a version of OPERA that was right around seven light years long. Sooooo.... most of them don't miss the detector so much as they simply pass right through it, and they continue to pass through the mountain, through the atmosphere, and go off into space, where they pretty much continue to pass through every star, planet, gas cloud and galaxy they encounter.
For what it's worth, a single neutrino would have to pass through about forty million Suns before it had a 50% chance of having one interaction with any of the particles inside.
