Antarctica Environment

Earth's southernmost continent is not a nice place to be.   There's ice over a kilometer thick at the surface of most of it.  At the hottest point in the summer, the temperature is as cold as it is in the middle of winter where I live, peeking at 15C in the hottest ice-less valleys.   During the winter, temperatures drop as low as -80C.   The gleaming white surface can give explorers and scientists that visit sunburn in a matter of minutes.  There's also altitude issues due to the ice -- Antarctica is high, and with it, thin of air.  And yet, it can save the entire world.
  An elaborate plan to use Antarctican conditions to suck CO₂ out of the air has been proposed, using the high winds to create wind power, which would power giant freezers.  In the freezers, pressurized air would press CO2 into a liquid that would then sublimate into snow when ejected.   The wind turbine's power wouldn't be very useful for other things, since maybe 200 scientists live in Antarctica.   As time went on, this freezer and compressor would suck the carbon from the air, and leave it locked forever in the snow.
  Of course, being who I am, I couldn't help but imagine a potential improvement in this plan.  Snow falls very slowly in Antarctica on account of it being technically a desert.   What little snow does fall remains as ice for a millennia, so I could use this to lower the ocean.   To our wind-freezer system, we add a desalinization plant.     Ocean water is pumped through huge pipes up from the ocean, using wind power.   Under intense pressure, fresh water accumulates on the other side of semipermeable membranes.   This fresh water is then sprayed towards the pole.  In the freezing conditions of Antarctica, even boiling water tossed into the air will quickly solidify into snow.   Thousands of years worth of snow will fall every single day, preferably on top of the dry ice snow that we were creating.   As this accumulates, the sea level slowly drops, saving countless low elevation communities around the globe.
Of course, Slashdot poster gman003 found a minor rub with the whole thing:

The only thing I see stopping it is politics. In particular, America and China. Europe seems to at least recognize the need for action, and they're willing to work together to try things. China is generally too selfish and shortsighted to worry about the environment, but you could probably convince them if you could make it somewhat-profitable for them (just have the wind turbines and such made in China, that should satisfy them).
But then it falls on to America. And you're going to need America at least not fighting this plan, because if the US decides to actively fight it, it's not happening. Period. You'd also need them to at least chip in a good chunk of the funding if you're going to do the full plan, make a serious dent in CO2. Problem is, denying the very existence global warming is a political requirement for half the country. They'll fight it just on principle, and I can't see the rest of the country fighting back for a project that doesn't have any immediate gains for the US specifically. While some sort of "compromise" could probably pull it off, or with luck it could be swept under the rug and never become a political issue, that's not guaranteed.
Still, it's the best plan I've seen so far.

 There's no need for it to necessarily be government funded though, and I could definitely see American green charities paying for it, European engineers designing it, and Chinese engineers physically assembling it in place.

3rd World Washing Machine

If you asked demographer Hans Rosling what invention the world's poorest people would like, that I could give from my house right now, he would answer in an instant one thing that personally changed his own family's life: The washing machine. Wait, what?

If for some reason you can't see the video, it's his lecture he gave to TED in which he describes how the washing machine changed his own family in surprising ways. Before, laundry was difficult work, thrust upon women against their will, that sucked up the better part of a day just to get clothing clean and dry. When this was mechanized, time was freed up for more important things, like education. The washing machine liberated women, and freed them up to improve things both for themselves and for the men in their life. Hans personally describes his rise to academia because his mother was freed up to tutor him.
Except, if I were to give the washing machine that I use to someone in the poorest part of the world, it would be a useless cube of steel from their perspective. They don't have running water. They don't have electrical connections, and when they do, those connections cannot be relied upon, as they often go out for weeks at a time. (Sometimes someone steals the copper, cutting the power, or the power gets cut for political reasons, or there's a strike at the power plant, which is then forced to shut down lest something get damaged while not maintained.) So...what to do?
Hack A Day reports that enterprising inventors have two designs for washing machines that can be operated with a bucket of water and hand-power, yet are far less laborous than the traditional fire-heated hand scrubbing. In one, the water, soap, and clothing is put into a barrel that resembles a water cooler. By repeatedly pushing a switch with one's foot, everything inside is spun around like a salad shooter, which causes all the soiled material to stick to the soap instead of the clothing:

The other option is a machine like a stationary bicycle connected to a barrel. The clothing, soap, and water goes into the barrel, the barrel is closed, then you pedal to agitate the clothing. And just like all the other machines, the frothing mixture makes the soiled material bind to the soap, which then comes out of the mixture:
Of the two options, I predict that the bicycle model will be more popular, as stationary bicycles are already a novelty in the poorest regions, where bicycles are an expensive but extremely useful form of transportation. A bicycle is like a walking multiplier -- The same effort makes you go farther and faster. No further investment is required after the bicycle, and what experience these people have shows them that bicycles can be fun.
In either case, an increase in the utility of human labor is surely a good thing.

Radiation Pigeons

When the Chernobyl nuclear plant near Pirpyat, in what is now the Ukraine, melted down in 1986, it was a worldwide disaster.   Radiation spread as far away as Kansas, and Pirpyat is now massively radioactive, and judged uninhabitable.  A few very stubborn people live there, and made an incredible discovery.  A type of yeast there developed the ability to eat gamma radiation.  As food.    This species of yeast is also universally found in pigeon feces.
Gamma radiation is the lowest-mass type of radiation produced from radioactive decay.   It takes several feet of lead to stop it due to its high energy,and it's absolutely hazardous to human health in the same way as touching a red hot stove would be.   Also, outer space is absolutely full of it, which is a hazard to would-be space travelers.  
These two facts can be combined to form two mad inventions, and I'm not sure which one is crazier.
One, we can clean up radioactive spills by spreading bread all over the affected area and then releasing some pigeons, which can easily be caught in most major cities in North America and Europe.   When these pigeons poop all over the place, the yeast will get right to work eating up all the radiation, making the area inhabitable years sooner than it would otherwise.
Two, we can keep a thin layer of pigeon poop in the outer hull of space going vehicles.   In the depths of space, the yeasts will absolutely feast on the radiation, and only very little would reach the astronauts.  Space travel would be lighter, cheaper, and safer.

Hybrid Home Power

Someday I want to have a solar powered home, and I've been gathering supplies for it.  I have about 710 Amp Hours worth of batteries, but I keep shying away from buying the panels, which tend to run in the hundreds of dollars.   Obviously, this dream will have to wait.

Or will it?   An electronics engineer has created a system to automatically switch between a solar-battery system and mains power.   Why?   The solar-battery system is free to you once paid for, but it can run down, especially if there's multiple cloudy days in a row or if your need for electricity is high (especially for air conditioning in hot summer months...my home city is technically a swamp.)

The system periodically takes a read of the battery capacity.  If it's full it swaps the entire house over to battery power.   If it's half full, it starts swapping circuits back to mains.   And if it's empty...mains for you while the system recharges.    Once set up, the user of this system could get the most economical power possible at all times.

One issue -- there is a brief cutoff while it swaps electrical systems.   Users of lamps and refrigerators probably won't notice.   Users of computers would have theirs inexplicably reboot.   A UPS (uninterruptable power supply) would be required for all computers in this house.   Preferably with the alarms turned off, as they by default sound an annoying alarm every time there's any issues with the power whatsoever.

Curing AIDS

Since it first appeared in America in 1985, there has been an intensive amount of interest in a treatment of some sort of the Auto ImmunoDeficiency Syndrome, or AIDS.   Other countries may have been interested when first exposed as well.  And according to Slashdot, we may now have it.   Supposedly, 3 people have been completely cured of the disease, which was previously minimally treatable and guaranteed fatal.
This is still tentative and prone to additional testing, since case #1 apparently has some radical differences with cases #2 and 3, covered in the article.   The theory relies upon bone-marrow transfer immunity.   When you receive a bone-marrow transplant, you inherit with it the donors immune system capabilities, including all vaccinations.   In this case, one of the rare people who was completely immune to AIDS (for genetic reasons mostly) donated bone marrow to these two patients, who inherited the immunity. 
If this can be confirmed, this will mean a radical new hope for the world's suffering.  Still no cure for the common cold or herpes, though.

Heart Jellyfish

Via Slashdot, I have learned of the world's first artificial animal -- a jellyfish made of plastic and rat heart cells.   The benefits are surprising and unexpected.
This jellyfish like thing starts to "swim" when exposed to electric currents, just as hearts beat in time to electric currents.   Put this thing in a tank of sugar water and attach a pacemaker, and you have the perfect environment for testing heart drugs.
Traditionally, heart drugs had to be tested by breeding rats with sick hearts, injecting some rats with the drug and some with a placebo (saline solution to make sure that results aren't just some weird side effect of injections in general), and noting their recovery or death.  Then human clinical trials were required because rats don't respond quite the same as humans.  (Doing the original testing with humans would be condemning some humans to die, which people won't put up with.) All of this was expensive and took a lot of time.
So instead, we could make a human heart cell jellyfish, put it in the tank, and expose it to drugs dissolved in the water.   The effects of the drug become apparently relatively quickly, suggesting which drugs, if any, are good candidates for a successful clinical trial.
The rat version?  Proof of concept.

Counterfan

As an IT expert, I am surrounded at all times by whirring fans, except when I am driving, in which case rumbling motors.   These fans are to keep the electronics cool enough to function.   While there are replacements, such as watercooled systems, that are significantly quieter, such systems are always significantly more expensive.
However, sound is ultimately a waveform, and interferes with itself destructively.   A +1 and a -1 waveform will, when put together, combine to form 0.   You can buy noise cancelling headphones that work using basically such a principle -- a microphone records the current sound, a microchip inverts the signal, and this is played into the headphones, cancelling the current sound.   This gave me an idea to make computers quieter.

Instead of one case fan whirring away, there would be two rotating in opposite directions.   The noise they produce would have opposite waveforms, cancelling each other and making the computer very quiet indeed.   A small bubble of space between them would have higher than normal pressure, and a vent would be requires to shove this air out of the way.   The case would then have negative pressure, and slowly suck air from the room.   Filters would be required in the case to prevent dust buildup on the electronics, which is somewhat of a pain in the neck to clean.  (Dust interferes with thermal transfer.)