Passive Window Cooling Idea

I may be a little obsessed with the Fan Group's research into radiative cooling.  (what can I say, I really hate excessive summer heat).

As the Greater Boston area is in the midst of a rather unpleasant summer heat wave, the mind turns to ways to help cool our human made environments.  (A big thanks to Willis Carrier for inventing modern AC)  While active heat pumping has the advantage of being incredibly fast, it does increase our civilization's energy demands, and until those energy sources are no longer adding greenhouse gasses, we are leaving ourselves in a nasty little feedback loop.  One potential means of increasing how efficiently we cool our homes, would be to create a window unit that passively provides radiative cooling while still allowing light through.  The design would have 3 major parts, the transparent cooling surface, heat pipes, and a small solar panel to power a fan.  After a user puts their cooling panels into place, the houses heat would be transported from the inside through the heat pipes.  To ensure that as much heat is being taken away from the house as possible, a small fan attached to a heat sink, similar to what you would see inside your computer, would blow air as necessary.  Sounds great in theory, but let's try to figure out how useful this idea would be.

Fig 1 On the left a flat panel trying to radiate heat away
on the right, the bumpy pattern points the heat towards space

 Each square meter of radiating material would provide roughly 850 watts of cooling or the equivalent to 2900 BTUs (about half the cooling of what a window unit made for a small room would provide.  This means that for a small room (about 125 square feet), you would need about 2 square meters of cooling surface (I am making a distinction for reasons I will go into later).  Without knowing how heavy all of the elements would be it would be pre-mature to comment on how unwieldy the mass of the system would be, that being said just that amount of area would be hard.  If this magical room had 4 decent sized windows, you would still need each panel to be at least 0.5 m by 1 m (or about 19.75 inches by 39.5 inches, unless this thing is folded up before you open it, not easy to safely place out of your window).  The reason the size of the panel needs to be at least half a meter by a meter, not exactly that size is a matter of how radiative cooling works.  Black body radiators need to be pointed at something colder than they are, in the case of this technology, the cold of space, if the surface of the panel is perfectly smooth, your cooling window is now most likely pointed at your neighbor's house, probably picking up the heat being reflected and or emitted by the neighbor.
 If the panel was to have a bunch of ridges creating a cool 3-D panel, probably a bunch of 45 degree slopes, you are only getting about 70% of the equivalent height of the array.  so now instead of being half a meter by a meter, the panel needs to be 0.5 m x 1.5 meters to get the same effect.  Now home owners have to spend the energy installing these far more massive panels, or putting in way more small panels to get a similar effect.

Fig 2:  Cooling panels to go outside big buildings

We are quickly running into a design that seems less and less appealing, which is what I came to realize, as excited as I am about passive window cooling units, they start seeming pretty silly as a primary means of cooling a home.  Small seasonal units might still find a niche market, for home owners who want to minimize the amount of work their actual AC system needs to work, but the real market for passive cooling technologies would most likely come from larger businesses that want seasonal cooling capacity.  Instead of designing a window unit that needs to be small and light enough for a home owner to put in, engineers should focus their efforts on creating two types of passive cooling installations, seasonal and permanent.  Designing a building to permanently have passive cooling systems on the outside, would make the most sense as to be customized for the building's use case (read too difficult to properly be analyzed in this blog), the seasonal solution is a bit easier (as I am looking at the problem from my perspective).  Imagine giant shutter looking structures. some intended to allow light in, others to maximize cooling.  Businesses and organizations who require massive amounts of air-conditioning could lease these panels and have them place around their building at the beginning of the summer, drastically offsetting how much energy the would need to devote to air-conditioning.  The challenge for this use case is the business atmosphere, realistically without either utility or government mandates to minimize peak energy consumption during the summer months, it could be difficult to inspire wide spread adoption of this kind of cooling technology.  If society had the will power to invest in more passive cooling technologies, there would be less demand for peaking power plants (the most expensive types of electrical generators), reducing the overall cost of energy, which is generally a good thing.

A quick note on the passive window unit.  While I don't think it makes sense for most American consumers, I do think the idea has merit in regions where power is less reliable or more expensive.

The idea behind this post is I generally only quickly outline an idea or act like I've seen the future and it must include my "brilliant" solution, I wanted to convey, at least in a small way, how I iterate through ideas and what problems I try to consider.  I hope this provides a small sense on how I try to create solutions to problems.

As always, questions, comments, feed back what-have-you always welcome.

Br(e)aking In Space

A common theme in the planning of deep-space missions(and this blog), is slowing a spaceship down enough to enter into orbit around a particular planet or moon.  As a general rule mission planners at NASA, ESA, and Roscomos need make sure the mission has enough fuel to get their ship going the right speed.  Generally speaking you can slow your ship down using two tools, rocket fuel and the gravity of other planets (I won't try to communicate gravity boosts/br(e)aking because I'm not familiar enough with the concept to do a reasonable highschool physics explanation(use the link if you want to know more)).  What I would like to suggest is a way to augment the rocket fuel option.

One of the many proposals that scientists and engineers have put forth for reducing the cost of launching ships into Earth orbit, is the use of micro-wave lasers (called masers) to help to heat up rocket fuel, the warmer the rocket fuel is, the more energy coming out of the engine's exhaust port.(this is like way over simplifying it).  This is awesome and hopefully sooner than later it will be another alternative way for research satellites to enter orbit (humans may not want lasers pointed at their rocket ship during the near term (personally it would depend on proven safety records of various technologies available), but how does it help us change velocity around other planets.  Short term, not at all.  Looking towards the future, it isn't unreasonable that there will be a relatively steady stream of space probes , and hopefully human explorers, trying to get around the inner solar system.  At that time governments and private bodies might begin to collaborate on creating a network of maser base stations on the larger rocks in the inner system of planets.  Initially the stations would only be placed on our Moon and one of Mars' moons.  Assisting astronauts on their missions to the Red planet and back, as time went on other large asteroids could add these laser arrays to increase mission flexibility.

While I am excited about this idea, that being said it wouldn't be perfect, getting the arrays at the target destinations would not be easy, so probably not a good idea for the first missions.

If engineers and budgets allowed for it, I would try to emphasize the energy beaming system to put out different kinds of power, from visible light to micro-waves.  The larger range of frequencies would allow for different missions to benefit, for space probes returning from the outer planets, the beams could focus additional power for the ion engines, either reducing the needed mass of the solar panels or just overall boosting thrust.  For missions not using ion engines, the focus would be on the use of the maser.

Additional ideas and comments are welcome, thanks for taking the time to read.

*7/26/2016 An edit I wrote break not brake, an observant reader had the decency to inform me of my mistake privately, Sorry 'bout that.

A Thought on Solar Sails

As several posts on this blog have already let on, I am very excited about Breakthrough Starshot.  (the collaboration between Steven Hawking and Yuri Milner into funding research into developing really small spacecraft, that by use of solar sails, would be launched towards Alpha Centauri)  

One of the questions that has been needling away in the back of my mind has been communication back to Earth.  (this question is also a focus for some of the Breakthrough Starshot team's research)  The problem is relatively straightforward, under this mission strategy to get probes to another solar system, you need to make really really low mass probes.  Less mass means less energy necessary to get to really high speeds.  Totally reasonable, the trade off is, the smaller you make the probe, the less space it has for things like, power generation and communication equipment.  The less energy you have to communicate, the harder it is to be heard.  Imagine trying to look for a lightning bug while looking at a massive spot light (this is not my analogy, I took it from a National Geographic story that I semi-recall on the search for exoplanets (alas I don't remember it enough to provide a source right now)).  The lightning bug in this story is our probe, the spot light, Alpha Centauri's stars.  Searching for this lightsource aka, the probes data transmission might just be too crazy, even for our future generation's technology.  

Let us not rely on the amount of signal a single gram of space probe can generate.  There is a beautiful alternative, and it is part of the probe's design, the solar sail.  The solar sail for even an incredibly small probe, would need to be huge, according to wikipedia, a solar sail 800 m by 800 m would produce just over 5 Newtons of force (imagine the amount of effort it takes to pick up a can of soda.  Now imagine you need enough material that when spread out the sail would cover 128 football fields.  That's a lot of area, potentially that is a lot of room for a potentially useful communications tool.  One potential means of using all of that area for a good secondary use, would be to create a material, that for some frequencies of light, it is incredibly reflective, preferably to the color of light that the lasers used to push the probe towards Alpha Centauri would use.  That part is easy, make a substance that is really reflective of one color, the challenge would be this, in addition to reflecting that one frequency of light, it would need the ability to change the frequency of light coming through one side to another on the other side.  Imagine for instance this special material when you shine blue light at it, on the other side yellow light would shine through.  Scientists are already doing work along those lines with materials called quantum dots.  If future researchers are very clever we could make special quantum dots that change one type of photon into another, but only if that quantum dot has been told to.  So now when we shine our blue light at this special material, normally blue light shines through, but when we specially alter that material (think apply a certain voltage, a chemical agent, what have you) now that light is yellow.  (I'm using actual colors for "ease" of communication).

2059 The first Breakthrough Starshot probe begins to fly through Alpha Centauri system, the incredibly small command module begins recording the data that scientists have waited over 25 years for, on its journey through this new solar system.  As the probe gets closer to Alpha Centuari A, systems unused since leaving the inner solar system over 20 years ago begin to activate.  On board controllers initiate a test sequence, confirming that the signalling quantum dots embedded in the solar sail can still convert the star's UV light down to one of A's emissions gaps.  After confirming that the system works, the probe begins to rapidly flicker, alternating between allowing light through unchanged, and emitting downshifted light that astronomers can detect trillions of miles away.

2063  Scientists confirm what had been suspected for years, clear indicators of potential microbial life changing the atmosphere of one of the moons of the Centauri system.

The core concept here doesn't necessarily require that the solar sails only manipulate one small band of the electro magnetic spectrum.  I honestly don't know what the limits would might be.  It could be that the system can alter several energy frequencies, but only be altered one time.  (this still leaves the potential for some simple yes/no messages being sent back)  for example Yes probe 1125 is working correctly and No it hasn't detected some type of organic molecule we associate with life.

Anyways I hope you enjoyed, feed back and questions are always welcome.

Augmented Reality and Getting Rid of Fences

Or How Technology Could Destroy the Cowboy

This idea is several years old, it lay dormant, until the joy of Pokemon Go brought it back.  Currently farmers who have live stock will often need to enclose their property with many miles of barbed wire or electric fencing to control where their animals are at a given time.  In an era with ever cheaper augmented reality technologies it could soon be possible to create smart goggles for animals.  Ok, I bet you're thinking, this is crazy, but bear with me.  If I have a large herd of cattle, I can equip them all with special goggles, that would allow ranchers to tell the cow should be at any time, all without herding the animal.
The goggles would provide a visual overlay onto a given animal's field of view, and at any time the cow, sheep, goat, etc... tries going into an area where a farmer doesn't want them, the goggles would provide a visual cue to make them want to go some other direction.  If the visual cue isn't enough, a system similar to a dog's shock collar would be activated to provide negative reinforcement.  The technology could go even further, scientists are developing bio-medical sensors to look for health indicators, the goggle system could actively report the health and location of all of a farmer's cattle, as time goes on the system would even include diet control, so when a cow goes up to its feed pen, the machine ensures that any nutritional gaps are filled.  Now the cost of this technology would need to be low, but in theory secondary cost savings could raise what that acceptable price would be.  First the reduced need for fence maintenance, probably a good thing, theft prevention, now the cows will only look for people that are authorized to do anything with the animal, if something isn't authorized, well it will look scary and the cow would go the other direction.  Harder to quantify now, but my gut says it might be useful, reducing ecological where wear and tear, as farmers no longer need to directly watch their herd, the computer can keep them grazing over a much more dynamic landscape, reducing the negative impacts of too many cows in too close an area over a given time.

(this article is now making me want to think more about smart farming, I'll try to keep coming up with additional ideas, and make a mega post later on)

As per usual, please feel free to comment share, feedback is always appreciated.

Edit July 14 2016
Another thought occurs, if this technology is affordable enough to equip the world's cattle with, we could start adding it to endangered mega-fauna (read elephants, rhinos, pandas)  There are stories of communities in Sub-Sahara Africa using lines of bee colonies to dissuade local elephants from entering into human farm land.  With augmented reality tech for wildlife, such needs could be reduced.  Secondary benefits could include the ability to monitor overall herd health, and serve as a way to provide evidence against poachers.  Another potential benefit for those in places like Alaska, young bears who haven't quite learned that entering human controlled spaces could be more actively convinced to not return to places with people, and when they see people in their territory, the human could look scarier.  (crap I should have been lazy and made this into a brand new post)

IoT and the 4th of July

Fireworks are awesome, but most of them are tubes of cardboard filled with things that go boom.  C'mon people, what's the problem, we live in an age where our cellphones have crazy features, a computer can beat a human being at Go, and some other awesome achievement like uhhh.. SpaceX (people like talking about them, for good reason reusable rockets are awesome).  Why aren't fireworks more sophisticated (there are probably good reasons but I'm being semi-rhetorical).  We live in an era of incredibly low cost computing.  $10 will now get you a computer capable of streaming video and handling 80% of the uses most people have for their computers (ok this doesn't include all of the required accessories, but the point remains).  What is to stop us from bringing these incredibly affordable platforms to making fireworks more awesome?  NOTHING!!! (aside from economics)
Imagine a small micro-controller that can be accessed via some kind of wireless network.  Possessing an internal timer, accelerometers providing up to 6 axis of pertinent information, and enough onboard power capacity to light the fire-work's fuse.  Now technicians for major events could go to an incredible degree of planning when it comes to the pyrotechnics.  During Boston's July 4th celebration, one of the cool fireworks, made a smiley face, totally awesome, unfortunately not all of the shells had the smiley face facing in the "correct" orientation, where the smile roughly occupied the bottom half of the explosion.  With accelerometers and orientation controls, the system could calculate at what time it could go off to look normal.  That's kid's stuff, let's go bigger.  One of the most dramatic parts of these displays is to have the grand finale follow allowing with a dramatic point in the local musical performance.  With a system that can be remote activated while in flight, now truly crazy displays could work with acoustic sensors near the musical performers and when the musical signal is given they go off.  Even crazier, you could set the activation code to start the detonation such that you would hear the blast of fireworks, right as the music is blasting.
Additional benefits could include safety in wiring.  Instead of having to manually wire to each individual cell, the technical crew could do much of their work in software.  Multiple redundancies in the activation mechanisms would help to minimize instances of the entire display going off all at once.  (For this to work, one approach would be to have the control chips to receive their power wirelessly and use that power to charge a capacitor, this would further help to reduce the potential for pre-mature activation)

Long term features, variable chemistry.  Some manufacturers might produce a limited range of smart fireworks.  The smart models would contain dynamically accessible chemistries, allowing for variation in the color and size of a given explosion.  Additionally moving to as bio-degradable a chip structure as possible, while it might be difficult to make the controller out of nothing but recyclable materials, the goal should be as close to 100% as possible.

More sci-fi.  3-D printing with the chips, hopefully, eliminating risks to the people responsible for making the explosive.

Starfleet Needs Better Androids

Sometimes you need to relax and zen out, for me that includes re-watching Star Trek.  During one of these viewings, I was reminded of something I wanted to comment on.  How smart is Commander Data?  In an episode titled "The Offspring"we are told that Soong type androids (read Cmdr Data and his "relatives") can perform over 60 trillion operations per second.  In the early 90's this number sounded insane, to perform a "mere" 1.9 billion operations per second you would need a Cray2 supercomputer, consuming more energy than 100 American homes (200 kW).  So now that we have a context for how powerful people thought a supercomputer needed to be to simulate a human being, let's look at today's state of the art computers, the fastest supercomputer is in China, the Sunway TaihuLight, it can perform 93 petaflops (thats 93 quadrillion operations per second), that make Data look downright dumb.  The PS4 and XBox One can both perform over one trillion operations per second (or 1/60th of Data's processing power).  If early 21st century engineers can produce this much processing power, what the hell is Star Fleet doing with all of their intellectual wealth?

Honestly, comparing numbers just comes off as silly, I get that, the writers were creating material for a particular time period, and within the context of the late 80's/early 90's the number they provided gave a sense of power and also gave nerds a number to geek out over.  This is a challenge for writers and futurists, coming up with ideas that are fantastical enough to inspire, but grounded enough to feel real.  Alternatively, the definition that citizens of the federation use for operation could be far more complicated than what we use.  For citizens of the federation, an operation could include thousands of sub-operations, one example, when processing an image there are many steps required to determine if there is a face on the screen a Star Trek level of operation might be the full action of find all potential shapes.  Honestly I am making things up.

Fun things that Data couldn't do, but our computers can.

Use contractions
beat people at chess

Edit 7/11
win at poker, according to this article, mathematicians have created computer programs that are incredibly difficult to beat by humans.  If Cmdr Data wanted to it would be possible for him to install said program into his own abilities.

there might be others but I can't remember