You will be part of an exciting future, because technology works on an exponential curve. That math-y word might sound intimidating, but 'exponential' just means that instead of steadily increasing (called linear, because it's graph is a line), the amount that it increases increases - that's not a typo :)
The linear could even start a lot higher than the exponential and it would still be passed quickly
The idea of exponential technology is best displayed by Moore's Law, which is not a law at all but rather a guess, in 1965, that computer processing ability would double every 2 years for the foreseeable future. And Moore was right: roughly every 2 years since then, the capabilities of computers has doubled. iPhone 3's have more processing power than ALL OF NASA had when they put a man on the moon.
Here's some of the great technology that's come out just this year that will have a profound impact on our future: (the picture is very big, you can zoom out in the "View" toolbar at the top of your screen)
In that short little lap, the pack burned all of its fuel - lifting and keeping that much weight in the air is forceful work, and they did this one with compressed air instead of flames.
The trick to lifting something like this is to send molecules downward at incredible speed. Newton's 3rd Law says that for every action, there's an equal and opposite reaction - in this case, the molecules of fuel that are pushed down out of the pack create an equal force upward on the pack. But the molecules weigh much less than the person + pack combination, so they have to be sent down with FAR more speed.
If only everyone was this excited about MOMENTUM :)
It's a basic momentum problem, and it's relevant for any sort of jet pack or spaceship technology, but not airplanes or helicopters. Particles must be ejected in the opposite direction of where you want to go at a very high speed, and that means you need fuel - but you can only carry so much, or it starts to weigh you down, requiring more fuel to lift.
So jet packs may always be just a fringe technology - we can have replenishable energy (solar, geothermal, hydroelectric), but not replenishable particles.
Great white sharks might be the scariest killer for most people, but these orcas know how to immobilize them by flipping them over, and then they eat their livers. Lots of cool videos in that link :)
Not how you thought this interaction would go, eh?
And finally, climate change is affecting sea turtles in a very unusual way: scientists have found that if water temperatures are too warm, only female sea turtles will hatch, making the extinction of the species inevitable if the oceans continue to heat up.
The "2nd Law of Thermodynamics" sounds intimidating, but really all it says is that whenever energy is transferred, a little bit of it turns into heat. Most of the time, that means the energy is no longer stored in any useful way: when our bodies digest food, or an engine turns explosions into forward motion, or your laptop charges, some of the energy is lost to heat.
The scientific word is 'entropy,' which is the idea that the universe is becoming "less ordered" as time goes on. Eventually the universe will be nothing but heat energy!
Although not nearly this dramatically
Most of this heat is completed wasted without being recouped - your body gives off heat into the air and your laptop charger just burns your leg if it's stuck under a pillow or something. But scientists have started to turn ambient heat back into energy, albeit not directly. The battery will still need to be charged while it is warm, and then when it's cooled it ends up with more voltage than was put into it. This doesn't violate the law of conservation of energy because the extra energy came from the heat!
Also tomorrow night there will be a meteor shower around 10pm to midnight, be sure to get outside to look at the stars :)
Check out these rock stacks - there's a great video at the end, go to the 6 minute mark to see something really cool.
Like rock Tetris
Some of these angles look impossible! It seems like there's no way that odd-shaped rock could be balancing on just one point, but there it is - these photos have not been altered in any way. The trick is to find the center of gravity.
The basic rule about center of gravity is this: if the center of gravity is supported, the whole thing is supported and balanced.
Scary.
This is part of the reason you throw your arms out to balance yourself - because as you move your arms, you change where the overall center of your gravity is. Try this: stand with your heels and butt totally against a wall and try to touch your toes. No matter how flexible or strong you are, it's impossible - most of your weight is in your torso, so when you touch your toes without the wall you HAVE to push your butt back to keep your torso over your feet:
Two ways to look unbalanced while still having your center of mass over your support (feet). (Source)
Without the ability to shift some of your weight to the back side of your feet, the weight of your torso will pull you over. Have you ever started to fall but you were able to swing your arms and move another leg to catch yourself? It's the same idea.
As the arms move, the center of gravity stays over his little feet on the rope
Your body knows its own center of gravity - I like to say that our instincts know physics better than we do.
The fundamental reason is that gravity is affecting all parts of everything - the center is really just the average of all the gravitational points.
These objects have a center of gravity in mid-air - which is why boomerangs curve!
This is also why top-heavy cars like SUV's can tip over more easily:
Some top-heavy cars add weight to the bottom to bring the center of gravity lower - making it harder to topple
So be safe with your center of gravity!
One more cool thing, this guy can do push-ups without legs by having a long board that keeps his center of gravity over his hands:
Still requires strength, but no amount of strength would make this possible without the device
Our bodies give off smells we didn't even know we had! Dogs have more than 4 times the number of olfactory senses that we do, so they can detect what we didn't even know was possible.
Ever wonder what empty space would do your body without a space suit? Check it out - there's some good stories here, including a time that an astronaut's space suit tore and he didn't even notice! I'll probably expand on this link later :)
Find out more from the astronauts perspective in this long video - it took me awhile to load, but it's full of awesome images and real astronaut interviews.
The Aurora Borealis as viewed from space - want to know more? Ask in the comments!
You're probably sick of this refrain: that we are polluting the planet with our unsustainable energy use and plastics that will never biodegrade. But there is hope, I promise! We have to keep pushing, insisting that there's a problem so that the "higher-ups" will actually do something about it, but people are also working on it.
This company wants to pave all of our roads with solar panels - and they claim that they could power the entire country, including charging electric cars on the roads themselves through the process of induction.
Induction is when you charge something just by being close to it - it's possible already with those cool cell phone charging pads. Basically, any time you have a magnetic field and you move a wire through it, the magnetism moves the electrons and produces a current through the wire. Then you can use that wire to charge a battery:
Awkwardly, you have to read the steps in counter-clockwise order
Germany is already on a roll with energy-saving technology that is sustainable - last Sunday, 74% of their power was coming from renewable resources. Now, why would it only be for a day? Because wind, water, and solar power are inconsistent - and currently, almost all power is used as soon as it's produced, not stored for later.
Now what about the plastic? If only it was biodegradable, or even edible - yes, that's a link for a reason: edible water bottles exist. Make one yourself by following this video:
This is the last day to legally watch this awesome video from the International Space Station:
The copyright agreement runs out at the end of the day
Can you imagine being up there? So cool. Check out my previous post on orbit for why he's weightless, even though he's definitely being affected by gravity!
Here are some very cool gifs of high tide vs. low tide all around the world - what a change in water level! These alternating pictures were probably taken at a very certain time of the month though, when tides have the most extreme differences: during a new moon.
If this were a picture of the new moon, it would just be a black square
You might already know that the moon affects the tides, but maybe not exactly how. Also, these pictures were taken during the day - why would the moon matter then? Because the moon's gravity is always affecting water on earth; in terms of time, it's easier to think about the earth rotating underneath the moon rather than the moon revolving around the earth, because earth's rotation around itself takes 1 day and the moon's revolution takes 28.
The strongest tides are when the moon is "new" (invisible) because that's when the moon is on the same side of the earth as the sun. No light can bounce off its surface and hit us - the angle is impossible, so the moon is invisible, but its gravity is now being added to the sun's to pull on Earth's water. Check it out:
There's some fun extra stuff in this video too
The water bulges out on both sides because it can't take water all the way from the other side, it only lowers the water level at the "sides," leaving extra water on the other end. The water is also being pushed outward slightly because of the centrifugal force, like if you took a wet basketball and spun it, flecks of water would go everywhere.
NASA also wants to try to build a small greenhouse on Mars, to see if Earth plants can grow there - in a contained environment of course, because Mars does not have enough atmosphere. We have to be careful though - microbes from Earth could actually colonize the red planet. Scientists are trying to clean rovers before they go.
And finally, off-topic but awesome, here's a video of ants being TOTALLY FREAKING COOL:
Ants really are amazing, even if they freak you out :)
We talked yesterday about how a guitar string produces such nice, long notes that are pleasing to the ear - I want to expand on that today.
A visible sound wave in the air - did you know that air can ripple just like water?
Sounds are all caused and detected by vibrations - when you speak, your vocal cords are vibrating in a way that you fine tuned during your early years of life. Starting at 6 months, babies actually watch people's mouths instead of their eyeballs because they're learning how different sounds are formed.
This is just adorable - you can tell that he has no idea what those words are, but he knows the sounds!Also he's 3 years old haha
All sounds are vibrations in a material that vibrates the material next to them - even and especially air. The air carries the sound through a series of vibrations; when they hit your eardrum, it vibrates and your brain decodes those vibrations.
Not quite like this little rascal
Sound's reliance on vibrations is why those waves cannot travel through space: there's no air to vibrate. If you knocked on the outside of a spaceship, they could hear it inside because the metal would vibrate the air inside, but you wouldn't be able to hear it even if you were very close. So every sci-fi movie with pew-pew laser noises or explosions (I'm looking at you, Star Wars), is scientifically inaccurate.
So, for once, a gif has the correct sound it would make
If a moving object (NOT in space) is making a noise, the sound wave produced will be smooshed in the front and elongated in the back; you can replicate this effect by moving your finger through the surface of water.
Sound waves are pretty similar to wave waves :)
This is known as the Doppler Effect, and you can hear it any time a noisy object comes toward you and then passes you by:
Trains are a common example because they make a lot of noise while they're moving
The Doppler Effect is only the difference in frequency, which determines the pitch of the sound - you'll hear a high pitch if the sound is coming toward you, and a low sound if it's moving away from you. Listen to the train again with this in mind :)
This is seriously my favorite topic in all of science! "Resonance" means something fits perfectly, like when a song or an art piece resonates with you and you remember it because of its power. In physics, it's the same idea: resonant frequency is the right-sized wave that fits perfectly inside its medium, and when it occurs very strange things happen.
Although this is actually a trick of the shutter-speed of the camera vs. the vibration of the string
When you tune a guitar, you are changing the density and tightness of the string until the wave created when you pluck it fits perfectly between the two ends. When the wave doesn't fit, your ear can tell the difference: the sound is just off and doesn't last nearly as long. That's because when a wave fits, it forms a standing wave:
Notice that the wave is only obvious when he's perfectly lined up with the proper frequency
Resonant frequency once destroyed a bridge when the British soldiers crossing it accidentally hit the perfect frequency of the bridge itself, and it shook to pieces; British soldiers now have a policy to walk off-step on bridges instead of staying in sync! This also happened in Korea, a group exercise randomly hit the resonant frequency of an entire building, causing it to evacuate for fears of an earthquake.
The most famous case, though, is this, the Tacoma Narrows bridge in Washington that collapsed in 1940:
Might look lame by today's CGI standards, but this is very real
I just found out though that it was NOT destroyed by resonant frequency - apparently physics textbooks have been explaining this incorrectly ever since it happened. The actual explanation is too intense for this space, but it's still a very cool video - and resonant frequency contributed to this bridge's demise, which only shook like this when the wind was exactly 42 mph.
Plastic is the bane of environmentalists: it's non-biodegradable (lasts forever, basically), harmful to wildlife, and it's made with petroleum - 3 strikes!
Unfortunately, plastic is far from "out" - it's just too darn useful to restrict. So we'll have to improve its biodegradability - and Harvard has taken a good step in that direction. They've made plastic materials out of shrimp shells! Alternative construction techniques will be key in building a sustainable future, because recycling doesn't always work:
And only 7% of plastic is recycled at all
Scientists have also figured out a new way to make concrete that repels water and actually flexes a bit. "Hydrophobic" (literally meaning "scared of water") concrete could prevent water from seeping into the road, where it can freeze and expand to crack the pavement. The expansion of water when it freezes is a very odd characteristic; most materials get smaller when they freeze and expand when they are melted, but water freezing forms a crystalline structure that makes ice slightly bigger than the water that made it up - which is also why it floats!
Animation vs. Real life
It's also important that concrete is a bit elastic (which means it can bend and still return to its original shape) so that it can take some punishment without cracking or breaking, requiring expensive repairs.
We'll talk about this particular concrete bridge tomorrow - it's literally my favorite thing to teach
That might not be what you picture when you hear 'lava,' but it doesn't always explode violently - there are places where it just oozes out of the ground like this, especially in active regions like Hawaii. Hawaii is unique because the island chain is the result of the Pacific plate moving over a hotspot.
There are a number of tendencies in the picture above, most notably in the size of the different islands; they are the shortest at each end for different reasons. Lo'ihi on the far right side is an active volcano, still growing - as are Mauna Loa and Kilauea; the volcanoes to the left of those are all dormant now, being slowly eroded by the ocean.
After Ni'ihau, the rest of the former volcanoes have been eroded under the ocean's surface and are now called "seamounts" - underwater mountains that do not break the surface, where they would be islands. Here's what the islands look like from above:
So the plate must be moving from left to right (and slightly upwards) in this picture, with the hotspot currently under the biggest island, Hawai'i, which contains Mauna Loa, and oldervolcanoes to the left and above
It's Friday again, so here's some interesting science stuff to get you through the weekend:
The ten most bizarre theories about why the dinosaurs went extinct - the comet theory is the one you know, but these are a bit more complicated.
Are you afraid of the right animals?
Spider bites are missing for a reason: Nobody in the U.S. has died from a black widow bite in the last 10 years
There's been a lot of work recently on stem cell research, and for good reason! Stem Cells are the special cells that can change into whatever is needed, the first cells that are produced when a fetus is growing. For the first time, scientists have grown working cartilage from stem cells.
And finally, a very cool video about how the re-introduction of wolves into the Yellowstone National Park actually changed the flow of rivers in the area, in addition to revitalizing the entire ecosystem:
We talked about the mechanics of evolution yesterday, but I still didn't explain how life started in the first place. We're definitely entering theoretical territory today, because nobody knows for sure how the world went from lifeless to the first single-celled organisms.
You can click through this slide show for some of the predominant theories, but the main one is covered better here - basically, amino acids came first. You wouldn't call them life yet, but amino acids are the building blocks of proteins - when amino acids assembled themselves into proteins, the proteins started enacting relatively random processes. Chemical reactions don't require "life" as we would see it - but if a chemical reaction results in replication, now you're starting to look more like a living thing.
Random at first, but once they start connecting to each other the behavior changes
As I mentioned yesterday, this all would have happened over a VERY long period of time. Once cell start copying themselves, sometimes making mistakes that sometimes result in adaptations, then the evolutionary process has begun, and different species can begin to exist - all single-celled at first, but then another mutation causes cells to start working together and that cooperation has an advantage, so if that 'team' of cells replicates, now there's a multi-celled organism.
The first divisions would have been random, but the resulting cells have a higher chance of dividing again
Another theory is that metabolism came first - metabolism is a lot like a chemical reaction, where a substance is converted into energy. When people say that I have a fast metabolism, they mean that I convert food quickly into energy, so very little of it is stored as fat. Metabolism at these early stages could have begun near deep sea vents, from the heat energy and varied chemicals.
Lava coming out of the ground at the bottom of the Atlantic ocean, creating new land at the fantastic rate of 13 cm per year - and maybe creating some life, too
Both of these have been deemed 'plausible' by lab experiments, but nobody really knows for sure. They also could have happened on another planet and been brought here by asteroids!
