Look out the window or walk down the street to nearly any river or stream in Minnesota right now and you are likely to observe two things about the river:
You can, of course, confirm these observations by investigating reports from gauging stations along these rivers, maintained by the U.S. Geological Survey. (See data for the gauging station serving downtown St. Paul.) But what is really happening?
Courtesy Liza Pryor
Until a river flows over its banks, it is considered to be in a “bankfull” state. In this state, the water flowing through the river is confined to a relatively fixed channel area. Simply put, floods occur because more water is being introduced into this channel from upstream, due to snowmelt, heavy rains, or a dam breach. As this added volume of water moves through a fixed area, it both increases in velocity and in depth until it overflows the banks, at which point some, but not necessarily a lot, of the volume and velocity moving through the channel are reduced.
Scientists call the rate of flow through a channel “discharge." Discharge is defined as the volume of water passing through a given cross-section of the river channel within a specified period of time.A simple equation for determining discharge is
Q = D x W x V
where Q = discharge, D = channel depth, W = channel width and V = velocity.
Looking at this equation, it is easy to see that if discharge becomes greater and channel width is fixed, then an increase in both volume and depth (or height relative to the banks) is likely to be the cause. Discharge can be measured in cubic feet per second or cubic meters per second, for example.
But is the river flowing at the same rate at the surface as it does along its banks and beds? Understanding this requires investigating some more detailed equations, as the banks and bed introduce friction, which affects the rate of flow.
To learn more about rivers and how they flow, you may want to check out the works of Luna Leopold, and M. Gordon Wolman. In particular:
Also, check out our full feature on the 2010 Mississippi River flooding.
As of 11:19am, the US Geological Survey is forecasting that the Mississippi River will crest here in downtown St. Paul at 18 feet.
That would put Water Street and the lower section of Lilydale Regional Park underwater (at 14'), require secondary flood walls at the St. Paul Downtown Airport (17'), submerge much of Harriet Island (17.5'), and make Warner Road impassable due to high water.
An 18-foot crest would also make this year's flood #9, historically speaking, bumping the flood of 1986 (16.10') off the top-10 list.
Also, check out our full feature on the 2010 Mississippi River flooding.
All day, up in the Mississippi River Gallery, people have been stopping to look out the window and watch the river.
Here's how the US Geological Survey sees it:
The river's rising, but not as fast as yesterday. And yesterday's rise outpaced predictions by almost a foot, but today the rise matches the predicted curve almost exactly.
So what are folks seeing out the window? Take a look.
Also check out our full feature on the 2010 Mississippi River flooding.
Courtesy Liza Pryor
Courtesy Liza Pryor
Courtesy Liza Pryor
Courtesy United States Geological SurveyWhen I read this story the other day, I thought to myself: why didn't I think of that? Or maybe I did think of it, but as usual no one was listening when I pitched the idea for an action-packed spy movie about climate change. Or were they?
The Central Intelligence Agency does have a bunch of high-powered satellites and other "classified" instruments, so it's possible they've been using them to eavesdrop on my conversations with friends about possible sci-fi movie plots.
What's more likely: they figured out on their own that intelligence-gathering instruments could be really helpful to scientists, who can read detailed pictures of melting sea ice, growing desserts and other phenomena to better understand how climate is changing the planet.
The C.I.A. recently confirmed that it had revived this controversial data-sharing program known as Madea, which stands for Measurements of Earth Data for Environmental Analysis. If you decode that C.I.A. code name, it means that government spies are working with climate scientists to gather images and data about environmental change, as well as its impact on human populations.
Not everyone is convinced that climate change is a real threat to national security, and so some complainers are complaining that this collaboration between scientists and the C.I.A. is a misuse of resources, but what do they know?
Really? What do they know? So much of what happens over at C.I.A. headquarters is top-secret.
Maybe the whole thing doesn't sound that action packed, but I'm telling you, if you had the right actors playing the scientists, it could be a blockbuster. And if you have the right scientists analyzing the data, it might provide really valuable insights into global environmental change.
Courtesy ESACan it be true? Yes, for a mere $5,544 dollars round-trip airfare to Greenland! In March 2009, the European Space Agency launched the Gravity field and steady-state Ocean Circulation Explorer (GOCE) into orbit around our planet, which is now transmitting detailed data about the Earth’s gravity. The GOCE satellite uses a gradiometer to map tiny variations in the Earth’s gravity caused by the planet’s rotation, mountains, ocean trenches, and interior density. New maps illustrating gravity gradients on the Earth are being produced from the information beamed back from GOCE. Preliminary data suggests that there is a negative shift in gravity in the northeastern region of Greenland where the Earth’s tug is a little less, which means you might weigh a fraction of a pound lighter there (a very small fraction, so it may not be worth the plane fare)!
In America, NASA and Stanford University are also working on the gravity issue. Gravity Probe B (GP-B) is a satellite orbiting 642 km (400 miles) above the Earth and uses four gyroscopes and a telescope to measure two physical effects of Einstein’s Theory of General Relativity on the Earth: the Geodetic Effect, which is the amount the earth warps its spacetime, and the Frame-Dragging Effect, the amount of spacetime the earth drags with it as it rotates. (Spacetime is the combination of the three dimensions of space with the one dimension of time into a mathematical model.)
Quick overview time. The Theory of General Relativity is simply defined as: matter telling spacetime how to curve, and curved spacetime telling matter how to move. Imagine that the Earth (matter) is a bowling ball and spacetime is a trampoline. If you place the bowling ball in the center of the trampoline it stretches the trampoline down. Matter (the bowling ball) curves or distorts the spacetime (trampoline). Now toss a smaller ball, like a marble, onto the trampoline. Naturally, it will roll towards the bowling ball, but the bowling ball isn’t ‘attracting’ the marble, the path or movement of the marble towards the center is affected by the deformed shape of the trampoline. The spacetime (trampoline) is telling the matter (marble) how to move. This is different than Newton’s theory of gravity, which implies that the earth is attracting or pulling objects towards it in a straight line. Of course, this is just a simplified explanation; the real physics can be more complicated because of other factors like acceleration.
Courtesy noneSo what is the point of all this high-tech gravity testing? First of all, our current understanding of the structure of the universe and the motion of matter is based on Albert Einstein’s Theory of General Relativity; elaborate concepts and mathematical equations conceived by a genius long before we had the technology to directly test them for accuracy. The Theory of General Relativity is the cornerstone of modern physics, used to describe the universe and everything in it, and yet it is the least tested of Einstein’s amazing theories. Testing the Frame-Dragging Effect is particularly exciting for physicists because they can use the data about the Earth’s influence on spacetime to measure the properties of black holes and quasars.
Second, the data from the GOCE satellite will help accurately measure the real acceleration due to gravity on the earth, which can vary from 9.78 to 9.83 meters per second squared around the planet. This will help scientists analyze ocean circulation and sea level changes, which are influenced by our climate and climate change. The information that the GOCE beams back will also assist researchers studying geological processes such as earthquakes and volcanoes.
So, as I gobble down another mouthful of leftover turkey and mashed potatoes, I can feel confident that my holiday weight gain and the structure of the universe are of grave importance to the physicists of the world!
Courtesy kevjblackThe Large Hadron Collider, the LHC, the World Destroyer, the Hula Hoop of God, the RC Matchbox Racetrack of Zeus, the Contraceptive Ring of Gaia herself… has been turned on.
You remember how concerned you were about this, right? You were worried that, based on what that friend said and what you read on that webpage, the activation of the LHC could be the end of the world, if not the universe.
Well, I know you’re nervous about what you might find, but I think there’s no avoiding it—it’s time for our regular self-check. I’ll walk you through it.
Stand up, and place your arms at your sides, palms in. Move your hands back and towards each other, keeping the palms facing in. When your hands have nearly met behind you, pull them forward and make a grabbing motion with your hands.
Did your hands go through thin air, or did they encounter something soft yet substantial? If the latter is true, we can all breath a sigh of relief—the LHC didn’t destroy life as we know it, and your butt is safe. For now.
The collider was actually turned on on Friday, although the first collisions from its accelerating beams of particles weren’t expected until early December. Much to the scientists’ surprise, collisions were detected as early as Monday. Check again if you need to, Buzzketeers.
If you’re looking for something to worry about, however, you might consider the following: the machine isn’t anywhere near full power yet. The protons involved in Monday’s collisions had been accelerated to the point where they had 450 billion electron volts. In the next few weeks, the LHC team will accelerate the particles up to 1.2 trillion electron volts, and, eventually, the facility should be accelerating protons to 7 trillion electron volts. When you’ve got protons heading each way, that means collisions will involve 14 trillion electron volts.
Yowza, right? I mean, the next most powerful particle accelerator, the Tevatron in Illinois, can only inject 900 billion electron volts into its accelerating particles—the LHC can do more than 15 times that!
But what does that mean? That sounds like a frightening amount of energy, so why doesn’t the Earth rumble and moan like a house in a storm whenever a large particle accelerator is turned on? It is a lot of energy, especially when you’re concentrating it into individual protons, which are, of course, very very small. But an electron volt is a very small unit of energy; it is defined as being “equal to the amount of kinetic energy gained by a single unbound electron when it accelerates through an electrostatic potential difference of one volt.” One trillion (that’s a million millions) electron volts—one fourteenth of the total energy of the LHC’s biggest possible collisions—is approximately equal to “the amount of energy of the motion of a flying mosquito.” That might be a deceptively small analogy—I’m sure it takes much much much more than a few bugs on treadmills to get the LHC powered up, and, again, that’s a lot of energy to be concentrated in a single subatomic particle racing at nearly the speed of light—but it’s an interesting comparison.
Strangelets and micro black wholes: 0; continued existence: 1.
Courtesy HillarieSo, I’m sure y’all have heard the news by now. The Large Hadron Collider, the largest and most elaborate scientific device ever built, has broken again. And it never even got the chance to end the world.
See, many people believe that the LHC’s attempts to catch a glimpse at the forbidden knowledge of the universe could, like a nerd’s efforts to peek into a locker room of large and aggressively athletic members of the opposite sex, go terribly wrong. Earth-endingly wrong. Sure, pretty much everyone who knows anything about it says that the LHC really isn’t dangerous in that way, and the odds that it would cause a chain reaction that would destroy the world are about the same as its chances of creating an army of teenage mutant ninja turtles. (There simply aren’t enough karate-practicing teenage turtles out there to mutate!) But that doesn’t seem to matter, because every time they try to turn that sucker on, something goes wrong, and we keep getting robbed of our first row seats at the end of the world (or, alternately, our seeding in the ninja reptile tournaments).
Do you know what killed the project most recently? I think you do, if you read this post’s headline. A bird. A little bird dropped its delicious toast on a piece of outdoor equipment (most of the LHC is deep underground). Presumably it was a bird, anyway. Whatever the case, a mystery slice of baguette found its way to some important equipment that was not baguette-proof, causing the machine to rise a few important degrees in temperature.
The damage caused to the machine wasn’t catastrophic. It shut down as the temperature in the circuit increased, which is a good thing, because if the LHC had been fully operational at the time, such an increase in temperature could have caused the superconducting magnets in the particle accelerator to become less-superconducting, and then all that energy from the near-light speed particles would… crash. Boom. But that didn’t happen, and the LHC should be up and running this winter.
A month ago, the internets were alive with discussion over the theory that the Large Hadron Collider was being sabotaged… by the future!
Naturally I ignored this news, because Science Buzz doesn’t credit nonsense like this with attention, and, what’s more, I’m familiar with the concept of someone at one point in time sabotaging his self at another point in time, and I know that it only goes the other way. Trying drinking something named after a cartoon at the end of an evening, and you’ll see what I mean.
I don’t totally get the idea behind this time travel sabotage theory, but the basic premise is that the universe, or “God,” or the fundamental forces of physics, or whathaveyou, aren’t into the possibility that the LHC could create a Higgs Boson. The Higgs is an important theoretical particle that sort of… ties the room together, if we’re calling the whole universe a room. Experiments at the LHC are trying to create conditions in which a Higgs might be observed. However, say a couple of respected scientist dudes, it could be that the Higgs is so “abhorrent to nature” that its creation would send ripples back in time to prevent it from being created.
Leaving aside the exact mechanics of time ripples, let’s consider what’s happening here. As we all know, while killing your own grandfather is often temptingly within reach, going back in time to kill your own grandfather is impossible. It could just be that no one is owning up to doing it, but the situation also describes a paradox: if you were to travel back in time to kill your grandfather, he couldn’t have created your mom or dad, who, in turn, couldn’t have created you, so you couldn’t go back in time to kill him, so… you get the idea. One might think that the universe attempting to undo the creation of a Higgs boson presents a similar paradox—if the creation of the boson is what causes it to destroy the equipment before it can be created, it would never be created, and therefore couldn’t destroy the equipment that creates it. Bleh. On the other hand, the scientists say, while you can’t kill your grandpa in the past (darn!) you can, say, push him out of the way of a speeding bus. Yay! (Unless the event of your grandpa’s bus-related death was the sole inspiration for your time traveling adventures.) The setbacks in the LHC’s operations, say the theorists, could be the universe trying to push us out of the way of a speeding bus, as it were. But what about the Higgs is so abominable? They aren’t sure about that.
It seems to me that there are still some brain-twisting complications in that theory. Cause and Effect, I think, are going to have difficult time sorting out whose clothes are whose in the morning. But… come on! A bird dropped some bread on the LHC! Since when do birds drop things on things? It has to be time-traveling mischief.
And, let’s face it, who hasn’t had the urge now and then? At the “Quantum to Cosmos” physics conference in Waterloo, Canada, seven physicists were asked, "What keeps you awake at night?" (Apparently, they meant “what issue in science” as opposed to love, money, or lack thereof.) The panel came up with some pretty heavy questions:
Why are the fundamental laws of nature the way that they are? There doesn’t seem to be any reason why they couldn’t be some other way. Are there, perhaps, other universes with other rules?
How does the Observer Effect work? This is a little deep for me, but apparently at the sub-atomic level, simply observing a particle over here can effect another particle thousands of miles away. How does nature do that?
What is the nature of matter, anyway? Especially the “dark matter” which is theorized to exist in outer space, messing up all our gravity calculations.
On a related note, will string theory ever be proven? String theory is the latest theory for how matter and energy interact at the sub-sub-sub-atomic level. And while it is very elegant and seems right on paper, no one has any idea how to conduct an experiment to prove or disprove it.
How do complex systems arise out of simple, basic particles and forces? You know, complex systems. Like life, the universe, and everything.
How did the universe begin, anyway? Physics can only take us back to a few fractions of a second after the Big Bang, a moment at which the universe was very small, very hot, and very dense. Before that, the laws of physics break down. No one knows how to describe the Bang itself, or how / why it happened.
Which brings us to, what are the limits of science? Science is based on observation and experiment. But, at some point, you run into ideas that can’t be tested. In theory, it’s entirely possible that there are other universes. But we’re stuck in this one—how would we ever know?
If anyone has answers to any of these questions, please send them to Canada ASAP. It sounds like there’s a bunch of scientists up there who could use a good night’s sleep.
Courtesy SiamEyeI don’t even know where to begin today! All I can think is “OMG!!!!” And each exclamation point I think is like a blood vessel bursting in my brain!
OMG pop pop pop
So why is this a day of excitement, instead of quiet family tragedy? Because the biggest explosions today aren’t happening in little tubes in my head, they’re happening in the world of science! (I don’t consider the physiology of my head to be science. More like magic. Or trial and error.) I just don’t know what to do with all this science.
See, unlike your average Friday Extravaganza, a Thursday Explosion has no focus; it’s just kind of all over the place. A mess! There are all these stories, but we really have to stretch to fit them into a single post… so the loose theme of this explosion will, fittingly, be “flying things.” Am I not helping? Just wait, you’ll see.
Normal mouse becomes flying mouse, doesn’t care!
Check it out: a baby mouse was put into a little chamber and subjected to an intense magnetic field. What happened? All the water in the mouse’s body was levitated. And because those squishy little mice are so full of water, the mouse itself levitated along with the water.
Unfortunately, the first mouse wasn’t quite ready for life as an aviator, and upon levitation, he began to, as scientists say, “flip his Schmidt.” Lil’ mousey started kicking, and spinning, and with minimal resistance in the chamber, he started spinning faster and faster. He was removed from the machine, and put wherever little mice go to relax. Subsequent floating mice were given a mild sedative before flying (pretty much the same thing my mom does), and they seemed cool with it. Now and again the floating mice would drift out of the region of the magnetic field, but upon falling back into it they’d float right back up. After remaining in a levitating state for several hours, the mice got used to it, and even ate and drank normally. Afterwards, the mice had no apparent ill-effects from the experiment (rats had previously been made to live in non-levitating magnetic fields for 10 weeks, and they seemed fine too.)
Aside from the excitement normally associated with floating mice, the experiment is promising in that it may be a useful way to study the effects of long term exposure to microgravity without bringing a subject to space.
pop pop pop
It’s true! Forget everything you thought you knew about great tits and get schooled once again, my friends, for great tits are killers!
I’m not talking about the senseless murder of bugs, either—everybody already knew that great tits are primarily insectivores. A population of great tits in Hungary have been observed hunting bats!
As fun as it is to keep writing “great tits” with no explanation, I suppose we should be clear that great tits are a type of song bird common in Europe and Asia. Little, bat-hunting songbirds.
Meat eating great tits had been reported in other parts of Europe, but it was thought that those individuals had only consumed already-dead animals. The tits of Hungary were actually observed flying into bat caves, where they would capture tiny, hibernating pipistrelle bats and drag them out of the cave to devour them alive. It even appeared that the birds had learned to listen for the bats’ disturbed squeaking (or, as I like to think of it, their horrified shrieking)—when the same noise (which is too high for humans to hear) was played back for captured tits, 80% of the birds became interested (read: bloodthirsty) at the sound.
If it really is just the Hungarian population that engages in this behavior, the situation also brings up the possibility of culture in the birds. That is, if this isn’t some sort of innate behavior, but something learned and taught, and passed through generations that way, it could be considered culture. Amazing! Great tits are cultured!
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Well, not so much flying as falling. But falling with purpose. (What was it Buzz Lightyear said? Oh yeah, “I’m so lonely all the time.”)
We all know about how awesome raptors are. I think it’s part of kindergarten curriculum now, just between how not to accidentally poison yourself, and why you shouldn’t swear and hit. Well, I remember reading a news item a couple years ago about how some paleontologists were thinking that raptors’ famous giant toe claws may not have been for disemboweling their prey. Instead, the scientists proposed, raptors would lodge the massive claw into the skin of their prey with a kick, and then use it to hang on to the unlucky animal while the raptor went bite-crazy. The researchers had made a simulation of a raptor claw, and found that it could easily puncture thick skin and flesh, it didn’t seem to be sharp enough to actually cut the skin. (Cutting is necessary for a good disemboweling.) One might argue over the strength and sharpness of raptor claws, considering that the fossilized bone claws we see in museums would have been covered with a tough, horny substance, which did not fossilize, but whatever—the new scenario was still pretty cool.
Now, the same group of paleontologists is proposing that raptor claws were also well suited to tree climbing. Raptors could have waited on overhanging limbs, and then pounced on their prey from above. Pretty neat! The researchers point out that the microraptor a tiny relative of the velociraptor, had feathered limbs to help it glide down from high places, so it’s not a stretch to think that its cousins were comfortable in trees too. “The leg and tail musculature,” one scientist says, “show that these animals are adapted for climbing rather than running.”
I’ll take his word for it, I guess, but I do have some questions on that point. There’s a dromaeosaur (it looks a lot like a velociraptor) skeleton here at the museum, and I seem to remember that its tale was supposed to be very stiff—it has these cartilage rods running the length of the tail to keep it rigid. I feel like a long, stiff tail would be a pain in the butt up in a tree. It’s not the sort of thing arboreal animals invest in these days. Also, I wonder what sort of vegetation was around in the areas raptors lived. Plenty of big trees with good, raptor-supporting limbs? (I’m not implying that there weren’t, I’m just curious.)
The researchers do acknowledge that tree climbing wouldn’t have been every raptor’s cup of tea, however. Species like the utahraptor, weighing many hundreds of pounds, and measuring about 20 feet in length would have been “hard put to find a tree they could climb.”
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Pretty neat stuff, huh? Explosions usually are. But you see now why I couldn’t wait for three posts to get it all out there.