Snow Ski

Posted by PITHOCRATES - February 26th, 2014

Technology 101

Gravity and Speed keeps a Skier’s Skies in contact with the Mountain and Provides Control

The Winter Olympics have come and gone.  And if you are a big fan of the Winter Olympics you probably were somewhat disappointed.  Especially if you’re a fan of alpine skiing.  Because it was just too warm.  They have the Olympics in February for a reason.  Because February is a very cold month.  And the mountains have a couple of months of snow on them by February.  Allowing the snow groomers to do their magic.  And turn those mountains into hard sheets of ice.

Yes, ski racers ski on ice.  Not snow.  If you ever skied on a mountain where there was once an Olympic downhill racecourse you will see very steep slopes of ice.  If you ski slowly across the fall line of the slope at the top of the mountain you will slide further down hill than you ski across the slope.  With your ski edges sliding across the ice.  And about the only thing that will stop your ‘free-fall’ slide down that steep ice-covered slope is the loose snow on the sides of the slope.  But if you travel down this same slope at speeds around 70 mph your skies will carve into that ice.  Giving you great control.  If you have the skills of an Olympic downhill skier, that is.  If you’re not as skilled as a downhill racer then you shouldn’t try this.  Because if you fall at speed up there you can do some real damage to yourself.

Downhill skiers love that speed, though.  And will give themselves up completely to gravity.  And let it pull them down these steep, sheets of ice at breakneck speeds.  With nothing to keep them from flying off the mountain and breaking their necks but their skies.  As gravity and speed keeps their skies in contact with the mountain.  Giving them control to stay on their skies.  And carve their way down the mountain.  Literally.

When a Skier leans over on a Ski the Curved Edge of the Ski carves into the Snow or Ice and Turns the Skier

In alpine skiing there are 5 different races.  The downhill.  The super giant slalom (known as super G).  Giant slalom.  Slalom.  And combined.  Which is a combination of two ski races.  One downhill race and one slalom race.  The downhill is the straightest and fastest down the mountain.  The super G is a little more ‘turny’ and a little slower than downhill.   The giant slalom is more ‘turny’ and slower than Super G.  And the slalom is more ‘turny’ and slower than giant slalom.  The downhill is all about speed.  The turns aren’t that sharp.  While the slalom is all about the turns.  With speeds that aren’t that fast.

Each of these races requires different types of skies.  The downhill race needs long skies that will absorb the bumps of rough terrain without bouncing off.  And speed is more important than turning.  While slalom skies need shorter skies to make sharper turns.  And because they are shorter they may come off the snow as they bounce over rough terrain.  So they match the ski to the race.  And because of the requirements of downhill racing these skies are available only to professional skiers.  You will not find them in any sporting goods store.  As amateur and recreational skiers could not control them safely on steep sheets of ice at downhill speeds.

If you look at a ski lying on the ground you will see that it is narrower at the center where it attaches to the ski boot and wider at the tip and the tail.  And it goes from wide to narrow to wide in a continuous curve.  This curve is the side-cut radius.  This is what turns the ski.  When a skier leans over on the ski the curved edge of the ski carves into the snow or ice.  Turning the skier.  The more curved the side-cut radius the tighter turns it will allow.  So slalom skies are more curved in the side-cut radius than downhill skills.

The Winter Olympics are in February so Ski Racers can ski on Mountains that are Hard Sheets of Ice

Looking at a ski resting on a hard surface you will notice something else.  The center of the ski will be off that hard surface.  While the tip and the tail will be in contact with that surface.  This arch—or camber—of the ski helps to force the ski into contact with the snow when you place weight onto them.  Especially the steel edges when turning.  When a skier carves a turn he or she will literally carve that turn into the ice of the mountain.  In a clean turn the tail of the ski will follow the same groove carved by the tip.  With a minimum loss of speed.  If the tail slides out of this groove and carve its own groove it will slow the skier down.  And in downhill skiing where first and second place can be separated by one one-hundredth of a second one slight skid in a turn can be the difference between winning and coming in second.

As downhill skiers leave the starting gate they will take a couple of pushes with their ski poles to help gravity pull them down faster and then assume a tuck position.  To decrease their air drag.  As they approach a gate they will turn by leaning on their edges.  The sharper the turn the more they will lean onto to their edges to carve a tighter turn.  And the more speed they will lose.  Which is why racers will look for the best ‘line’ down the mountain.  One that minimizes sharp turns.  Once out of the turn they will release their edges and ski on the bottom of their skies.  Gaining speed.  They will absorb the rough terrain in their legs.  And fight the compression of the g-forces with their legs.  They lean into turns, release their edges, ride on the bottoms of their skis in the flats, lean on their edges, etc.  At speeds around 70 mph.  As they carve their way down a mountain of ice to cross the finish line in the shortest amount of time.

As spring approaches the ski resorts warm up.  Some people love this.  Spring skiing conditions.  Loose snow on the slopes but warming weather.  So warm that a lot of ski areas will have events like bikini races or lingerie races where girls will ski down the mountain half naked in the warming weather.  It can be a real party on the slopes.  But the skiing will be horrible.  The snow will be melting.  It will be wet.  Granular.  Pushed up into piles.  Making it easy to catch an edge and fall.  And difficult to build up any speed.  Which is why the Winter Olympics are in February.  In the coldest part of winter.  With a lot of snow frozen on the mountain.  And they typically don’t hold them in subtropical climates.  Where the average temperature in February is 50 degrees Fahrenheit.  Like in Sochi, Russia.  Where skiers had to deal with spring skiing conditions.  And varying conditions.  As the snow at the top of a run was different from the snow at the bottom of the run.  Despite the amount of chemicals they put on the snow to try and raise the melting temperature of the snow.  Making these Winter Games not as good as past Winter Games.  If you’re a fan of alpine skiing, that is.  Or prefer seeing cold winter vistas at the Winter Olympics.  And not people lying on the bare grass catching a suntan.


Tags: , , , , , , , , , , , , , , , , , , , , , , , , , , , ,

Pendulums, Springs and Timekeeping

Posted by PITHOCRATES - September 25th, 2013

Technology 101

A Swing is a Pendulum that loses Energy due to Air Resistance and Friction

Remember what it was like to swing on a swing?  You sat down on a seat supported by two chains that connected to a bar above you.  When you were real young your mom or dad may have pushed you to get you started swinging back and forth.  As we got older we didn’t need Mom or Dad anymore.  We just pushed back with our feet.  Picked up our feet.  Pulled back on the chains as we swung forward.  As our forward momentum petered out we swung backwards.  Until that backward momentum petered out.  As we swung forward again we’d pull back on those chains again.  Until we began to fly.

Well, not fly literally.  But we’d swing back and forth, getting pretty high before we started swinging back in the other direction.  Going pretty fast as we swung through the bottom.  We could do this for hours because it hardly took any effort.  Most of the work was done by gravity pulling our weight back down to the ground.  Gravity made us go faster as we swung towards the bottom.  And slowed us down after we passed through the bottom.  Which is why few kids, if any, were ever able to wrap the swing around the overhead bar like in the cartoons.  As they could never build up enough speed to escape the pull of gravity.

But we could maintain that back and forth motion almost forever.  The only thing stopping us was a bathroom break.  Stopping to eat.  Stopping to go to bed.  Or stopping because we got bored.  If we sat still on the swing the distance we swung back and forth would get smaller and smaller.  Coming to a full stop if we let it.  Why?  Because the swing loses a lot of energy.  Though kids are small they catch a lot of air.  This air resistance slows down their motion.  There is friction where the chains connect to the overhead bar.  And with two chains our pulling would be uneven and twist the swing from side to side.  Creating more friction in the chain as the links twist against each other.

A Constant Period at Small Amplitudes makes the Pendulum Ideal for Timekeeping

The pendulum is probably the closest we’ve come to achieving perpetual motion.  In ideal conditions where there was no friction or air resistance the back and forth motion (oscillation) of pendulum would go on forever.  Even in the ideal conditions it would still take an energy input to begin the oscillation.  But even though we can’t create the ideal conditions for a pendulum we can get close enough to make the pendulum do useful work for us.

The parts of a pendulum are a suspended weight (bob) and a pivot point.  The weight of the bob and the distance between the bob and the pivot determine the distance the pendulum travels (amplitude).  One swing back and forth is one period.  The greater the amplitude the greater the period and the slower the oscillation.  The smaller the amplitude the smaller the period and the faster the oscillation.  The greater the distance between the bob and the pivot the greater the period and the slower the oscillation.  The smaller the distance between the bob and the pivot the smaller the period and the faster the oscillation.

Pendulums with small swings have a very useful feature.  The period will remain the same even if the amplitude does not.  So the effects of friction and air resistance will be negligible for small swings.  Making the pendulum ideal for timekeeping.  Such as in a grandfather clock.  Where the bob is suspended on a long rod from the pivot.  That oscillates in small swings back and forth.  When this period is one second it can advance a minute hand one minute with 60 periods.  And with gears and cogs connecting the axle of the minute hand to the axle of the hour hand 60 revolutions of the minute hand will move the hour hand one hour.  Gears and cogs make the minute and hour hands move.  But it’s the pendulum that actually keeps time with its constant period.  With one other element.

Early Marine Chronometers replaced the Pendulum with a Wound Spiral Spring in the Escapement

So what actually makes the hour and minute hands move?  Gravity.  Wrapped around one of these axles is a cable.  At the end of this cable hanging down in the clock body is a weight.  Think of a fishing rod when a fish strikes.  The fish will pull the line out of the reel until you start reeling it in.  This is what gravity does.  It pulls that weight down pulling the cable off of the main drive axle causing it to spin.  But it doesn’t spin out of control.  In fact, it moves in very short, discrete steps.  Because of the escapement at the heart of a pendulum clock.

An escapement is a gear and a locking mechanism.  The locking mechanism attaches to the pendulum and looks a little like an inverted letter ‘V’.  As this rocks back and forth with the pendulum it moves two teeth (at each tip of the ‘V’) into and out of the gear.  As it rocks one way one tooth moves out of the gear.  Releasing it and allowing the gear to turn.  At the same time the other tooth moves into the gear.  Locking it and stopping the gear from turning.  When the pendulum swings the other way the locking tooth releases, allowing the gear to turn.  Until the other tooth moves into the gear and locks it again.  This happens with every swing of the pendulum, giving it that characteristic tick-tock sound.

Before the pendulum clock the existing mechanical clocks of the day were accurate to about 15 minutes a day.  The pendulum clocks, though, were accurate to within 15 seconds a day.  Making it the most accurate time piece for about 300 years until the advent of the quartz clock around 1930.  One of the drawbacks of the pendulum clock was that it needed to be stationary.  Which made it poorly suited for ships which could get tossed around in rough seas.  Which was a problem.  For telling time was crucial for navigation.  As ships traveled away from the coastline they needed to find their position on a chart.  They could use a sextant to find what line of latitude (north-south location) they were at.  But to determine what line of longitude (east-west location) they were at they needed an accurate time piece.

Early marine chronometers used an escapement.  But replaced the accurate pendulum and weight with a less-accurate wound spiral spring.  Which found their way into wristwatches.  Before there were batteries.  They weren’t as accurate as a pendulum clock.  And you had to wind them up every day whereas a grandfather clock will keep time for about a week.  But a spring allowed miniaturization.  And the ability to tell time when you didn’t have the ideal conditions a pendulum requires.  Such as on a ship navigating across rough seas.


Tags: , , , , , , , , , , , , , , , , , , , , , , , , ,

Vacuum Toilet

Posted by PITHOCRATES - April 24th, 2013

Technology 101

The Siphon in a Flush Toilet sucks the Waste out of the Toilet Bowl

The common flush toilet in our homes is located in a bathroom.  A dedicated room in our houses.  Often times tucked away off of a bedroom.  Private and secure.  Where we can take care of any of our business with comfort and dignity.  It’s nice.  Hiding that part of our life away from the rest of the world.  In fact, some people are such nervous pooers that they can’t go anywhere but at home.  Lucky for them they didn’t live in ancient Rome where communal toilets were long benches with holes in them.  And people sat next to each other while doing their business.  Elbow to elbow.  Literally.

What makes the flush toilet in our homes possible is basically one thing.  They don’t move.  They’re permanent installations that sit on terra firma.  And because of that they can use gravity.  When we flush a toilet water pours down from a tank into a bowl.  Forcing the contents of the bowl up and over the drain out of the bowl.  The siphon.  Filling this pipe completely with water.  So that when the water falls down into the sanitary sewer pipe it creates a siphon.  Pulling everything behind it down into the sanitary drain.  Where gravity pulls it down to pipes under our houses and into the sanitary sewer system under the street in front of our house.  Where these pipes slope downhill towards the wastewater treatment plant.

The flush toilet works in our house because they don’t move.  And we can dig pipes deep underground.  Two things we can’t do on boats, trains and planes.  So early boats and trains had a simple toilet.  If you looked down into the toilet seat on a boat you saw the water.  And if you looked down into the toilet seat on a train you saw the railroad track underneath.  Which could really chill a pair of butt cheeks on a crisp winter day.  Making a cold toilet seat in your bathroom in the morning seem toasty warm by comparison.  Early planes had a chemical toilet.  Basically a port-a-potty.  Filling the air with the aroma of a construction site toilet.

The Suction of a Vacuum Toilet is greater than the Siphon of a Flush Toilet

Today in most countries you can’t defecate into a river, lake or ocean.  Or onto railroad tracks.  It’s not sanitary.  And just plain disgusting.  But because boats, trains and planes move a flush toilet with a bowl full of water just isn’t an option.  Because water in a moving bowl tends to splash out of the bowl.  Which can splash corrosive waste in nooks and crannies around the toilet.  Making a mess in the lavatory.  Though chemical toilets were an option and we used them for some time they just didn’t smell good.  Especially on an airplane.  As you just couldn’t roll the window down for some fresh air.

A flush toilet on an airplane has another problem.  Water has mass.  To carry water for flush toilets increases the weight of the airplane.  Requiring more fuel.  As fuel is the greatest cost of flying airlines and aircraft manufacturers do everything within their power to reduce the weight of an airplane.  Which is why today’s aircraft use a vacuum toilet system.  Where instead of using water and gravity to create a siphon they use a vacuum pump to create a suction.  A vacuum toilet does not use water.  There is no water in the bowl.  When you ‘flush’ a drain opens in the bottom of the bowl and a powerful vacuum sucks it clean.

The suction of a vacuum toilet is greater than the siphon of a flush toilet.  Allowing smaller pipes as the powerful suction does not allow any clogging of pipes.  Smaller pipes (and no water like in a flush toilet) reduce weight.  Helping to cut the cost of flying.  That powerful suction also sucks out all of the stink with each flush.  Another benefit of the vacuum toilet.  Which is a good thing in a small room without a window you can open.

A Truck transfers the Sanitary Waste from an Aircraft Holding Tank into the Sanitary Sewer System

Planes pitch up, pitch down and bank left and right.  Which would be a problem for wastewater moving under the force of gravity.  Or for water in a bowl.  Which is another benefit of a vacuum toilet system.  Which doesn’t use gravity.  Or water.  So the pipes of a vacuum toilet system can run in any direction.  Up, down or flat and level.  The force of the suction will pull the waste to the holding tank no matter the path it takes to the holding tank.

As the flight progresses people use the toilets.  And the holding tanks fill up with waste.  When they land they are pretty full.  And the airlines need to empty them.  If you ever watched an airplane at a gate after it lands you will see a whirlwind of activity.  Baggage and freight comes off.  Then they load baggage and freight for the next flight.  Cleaning crews enter the aircraft.  Food service cleans out the galleys and loads food and beverages for the next flight.  Fuel trucks refuel the aircraft (either from a fuel truck or a fuel hydrant system in the apron).  And then there’s the poop truck.  Which will open a hatch on the belly of the aircraft.  Connect a large hose.  Open a valve.  And drain the holding tank into the truck.  Pump in some blue disinfectant.  And make the toilets ready for the next flight.

The poop truck then drives someplace where they can dump their load.  Larger airports may have a special building for this.  Where they drive in and stop over a grate in the floor.  Dump their load onto the grate.  Water sprays onto the floor to help wash everything into and through the grate.  Where it falls into a ‘chopper’ pump to break down the solids more.  And then it enters the sanitary sewer system at the airport.  Where it uses gravity to flow downhill towards a wastewater treatment plant.  Just like it does when we use the bathroom in the privacy and security of our home.


Tags: , , , , , , , , , , , , , , ,

Conservation of Energy, Potential Energy, Kinetic Energy, Waterwheels, Water Turbine, Niagara Falls, Dams, and Hydroelectric Power

Posted by PITHOCRATES - July 25th, 2012

Technology 101

Roller Coasters use Gravity to Convert Energy back and forth between Potential Energy and Kinetic Energy

We cannot destroy energy.  All we can do is convert it.  It’s a law of physics.  The law of conservation of energy.  A roller coaster shows this.  Where roller coasters move by converting potential energy into kinetic energy.  And then by converting kinetic energy back into potential energy.

The best roller coasters race down tall inclines gaining incredible speed.  The taller the coaster the faster the speed.  That’s because of potential energy (stated in units of joules).  Which is equal to the mass times the force of gravity times the height.  The last component is what makes tall roller coasters fast.  Height.  As the cars inch over the summit gravity begins pulling them down.  And the longer gravity can pull them down the more speed they can gain.  At the bottom of the hill the height is zero so the potential energy is zero.  All energy having been converted into kinetic energy (also stated in units of joules).

Roller coasters travel the fastest at the lowest points in the track.  Where potential energy equals zero.  While kinetic energy is at its highest.  Which is equal to one half times the mass times the velocity squared.  So the higher the track the more time gravity has to accelerate these cars.  At their fastest speed they start up the next incline.  Where the force of gravity begins to pull on them.  Slowing them down as they climb up the next hill.  Converting that kinetic energy back into potential energy.  When they crest the hill for a moment their speed is zero so their kinetic energy is zero.  All energy having been converted back into potential energy.  Where gravity tugs those cars down the next incline.  And so on up and down each successive hill.  Where at all times the sum of potential energy and kinetic energy equals the same amount of joules.  Maximum potential energy is at the top.  Maximum kinetic energy is at the bottom.  And somewhere in the middle they each equal half of their maximum amounts.

(This is a simplified explanation.  Additional forces are ignored for simplicity to illustrate the relation between potential energy and kinetic energy.)

We build Dams on Rivers  to do what Niagara Falls does Naturally

So once over the first hill roller coasters run only on gravity.  And the conversion of energy from potential to kinetic energy and back again.  Except for that first incline.  Where man-made power pulls the cars up.  Electric power.  Produced by generators.  Spun by kinetic energy.  Produced from the expanding gases of combustion in a natural gas-powered plant.  Or from high-pressure steam produced in a coal-fired power plant or nuclear power plant.  Or in another type of power plant that converts potential energy into kinetic energy.  In a hydroelectric dam.

Using water power dates back to our first civilizations.  Then we just used the kinetic energy of a moving stream to turn a waterwheel.  These waterwheels turned shafts and pulleys to transfer this power to work stations.  So they couldn’t spin too fast.  Which wasn’t a problem because people only used rivers and streams with moderate currents.  So these wheels didn’t spin fast.  But they could turn a mill stone.  Or run a sawmill.  With far more efficiency than people working with hand tools.  But there isn’t enough energy in a slow moving river or stream to produce electricity.  Which is why we built some of our first hydroelectric power plants at Niagara Falls.  Where there was a lot of water at a high elevation that fell to a lower elevation.  And if you stick a water turbine in the path of that water you can generate electricity.

Of course, there aren’t Niagara Falls all around the country.  Where nature made water fall from a high elevation to a low elevation.  So we had to step in to shape nature to do what Niagara Falls does naturally.  By building dams on rivers.  As we blocked the flow of water the water backed up behind the dam.  And the water level climbed up the river banks to from a large reservoir.  Or lake.  Raising the water level on one side of the dam much higher than the other side.  Creating a huge pool of potential energy (mass times gravity times height).  Just waiting to be converted into kinetic energy.  To drive a water turbine.  The higher the height of the water behind the dam (or the higher the head) the greater the potential energy.  And the greater the kinetic energy of the water flow.  When it flows.

Hydroelectric Power is the Cleanest and Most Reliable Source of Renewable Energy-Generated Power

Near the water level behind the dam are water inlets into channels through the dam or external penstocks (large pipes) that channels the water from the high elevation to the low elevation and into the vanes of the water turbine.  The water flows into these curved vanes which redirects this water flow down through the turbine.  Creating rotational motion that drives a generator.  After exiting the turbine the water discharges back into the river below the dam.

Our electricity is an alternating current at 60 hertz (or cycles per second).  These turbines, though, don’t spin at 60 revolutions per second.  So to create 60 hertz they have to use different generators than they use with steam turbines.  Steam turbines spin a generator with only one rotating magnetic field to induce a current in the stator (i.e., stationary) windings of the generator.  They can produce an alternating current at 60 hertz because the high pressure steam can spin these generators at 60 revolutions per second.  The water flowing through a turbine can’t.  So they add additional rotational magnetic fields in the generator.  Twelve rotational magnetic fields can produce 60 hertz of alternating current while the generator only spins at 5 revolutions per second.  Adjustable gates open and close to let more or less water to flow through the turbine to maintain a constant rotation.

The hydroelectric power plant is one of the simplest of power generating plants.  There is no fuel needed to generate heat to make steam.  No steam pressure to monitor closely to prevent explosions.  No fires to worry about in the mountains of coal stored at a plant.  No nuclear meltdown to worry about.  And no emissions.  All you need is water.  From snow in the winter that melts in the spring.  And rain.  Not to mention a good river to dam.  If the water comes the necessary head behind the dam will be there to spin those turbines.  But sometimes the water isn’t there.  And the dams have to shut down generators because there isn’t enough water.  But hydroelectric power is still the cleanest and most reliable source of electric power generated from renewable energy we have.  But it does have one serious drawback.  You need a river to dam.  And the best spots already have a dam on them.  Leaving little room for expansion of hydroelectric power.  Which is why we generate about half of our electric power from coal.  Because we can build a coal-fired power plant pretty much anywhere we want to.  And they will run whether or not we have snow or rain.  Because they are that reliable.


Tags: , , , , , , , , , , , , , , , , , , , , , , , , , ,

Corduroy Roads, Positive Buoyancy, Negative Buoyancy, Carbon Dioxide, Crush Depth, Pressurization, Rapid Decompression and Space

Posted by PITHOCRATES - May 9th, 2012

Technology 101

Early Submarines could not Stay Submerged for Long for the Carbon Dioxide the Crew Exhaled built up to Dangerous Levels

People can pretty much walk anywhere.  As long as the ground is fairly solid beneath our feet.  Ditto for horses.  Though they tend to sink a little deeper in the softer ground than people do.  Carts are another story.  And artillery trains.  For their narrow wheels and heavy weight distributed on them tend to sink when the earthen ground is wet.  Early armies needing to move cannon and wagons through swampy areas would first build roads through these areas.  Out of trees.  Called corduroy roads.  It was a bumpy ride.  But you could pull heavy loads with small footprints through otherwise impassable areas.  As armies mechanized trucks and jeeps with fatter rubber tires replaced the narrow wheels on wagons.  Then tracked vehicles came along.  Allowing the great weights of armored vehicles with large guns to move across open fields.  The long and wide footprints of these vehicles distributing that heavy weight over a larger area.  Still, nothing can beat the modern rubber tire on a paved road for a smooth ride.  And the lower resistance between tire and road increases gas mileage.  Which is why trucks like to use as few axles on their trailers as possible.  For the more tires on the road the more friction between truck and road.  And the higher fuel consumption to overcome that friction.  Which is why we have to weigh trucks for some try to cheat by pulling heavier loads with too few axles.  When they do the high weight distributed through too few wheels will cause great stresses on the roadway.  Causing them to break and crumble apart.   

Man and machine can move freely across pretty much anything.  If we don’t carry food and water with us we could even ‘live off the land’.  But one thing we can’t do is walk or drive on water.  We have to bridge streams and rivers.  Go around lakes.  Or move onto boats.  Which can drive on water.  If they are built right.  And are buoyant.  Because if a boat weighed less than the water it displaced it floated.  Much like a pair of light-weight, spongy flip-flops made out of foam rubber.  Throw a pair into the water and they will float.  Put them on your feet and step into the deep end of a pool and you’ll sink.  Because when worn on your feet the large weight of your body distributed to the light pair of flip-flops makes those flip-flops heavier than the water they displace.  And they, along with you, sink.  Unlike a boat.  Which is lighter than the water it displaces.  As long as it is not overloaded.  Even if it’s steel.  Or concrete.  You see, the weight of the boat includes all the air inside the hull.  So a large hull filled with cargo AND air will be lighter than the water it displaces.  Which is why boats float. 

Early sail ships had great range.  As long as the wind blew.  Their range only being limited by the amount of food and fresh water they carried.  Later steam engines and diesel-electric engines had greater freedom in navigation not having to depend on the prevailing winds.  But they had the same limitations of food and water.  And when we took boats under the water we had another limitation.  Fresh air.  Early submarines could not stay submerged for long.  For underwater they could not pull air into a diesel-electric engine.  So they had to run on batteries.  Which had a limited duration.  So early subs spent most of their time on the surface.  Where they could run their diesel engines to recharge their batteries.  And open their hatches to get fresh air into the boat.  For when submerged the carbon dioxide the crew exhaled built up.  If it built up too much you could become disoriented and pass out.  And die.  If a sub is under attack staying under water for too long and the levels of carbon dioxide build up to dangerous levels a captain has little choice but to surface and surrender.  So the crew can breathe again.

Rapid Decompression at Altitude can be Catastrophic and Violent

Being in a submarine has been historically one of the more dangerous places to be in any navy (second to being on the deck of an aircraft carrier).  Just breathing on a sub had been a challenge at times while trying to evade an enemy destroyer.  But there are other risks, too.  Some things float.  And some things sink.  A submarine is somewhere in between.  It will float on the surface when it has positive buoyancy.  And sink when it has negative buoyancy.  But submarines operate in the oceans.  Which are very deep.  And the deeper you go the greater the pressure of the water.  Because the deeper you go there is more ocean above you pressing down on you.  And oceans are heavy.  If a sub goes too deep this pressure will crush the steel hull like a beer can.  What we call crush depth.  Killing everyone on board.  So a sub cannot go too deep.  Which makes going below the surface a delicate and risky business.  To submerge they flood ballast tanks.  Replacing air within the hull with water.  Making it sink.  Other tanks fill with water as necessary to ‘trim’ the boat.  Make it level under water.  When under way they use forward propulsion to maintain depth and trim with control surfaces like on an airplane.  If everything goes well a submarine can sink.  Then stop at a depth below the surface.  And then resurface.  Modern nuclear submarines can make fresh water and clean air.  So they can stay submerged as long as they have food for the crew to eat.

An airplane has no such staying power like a sub.  For planes have nothing to keep them in air but forward propulsion.  So food and water are not as great an issue.  Fuel is.  And is the greatest limitation on a plane.  In the military they have special airplanes that fly on station to serve as gas stations in the air for fighters and bombers.  To extend their range.  And it is only fuel they take on.  For other than very long-range bombers a flight crew is rarely in the air for extended hours at a time.  Some bomber crews may be in the air for a day or more.  But there are few crew members.  So they can carry sufficient food and water for these longer missions.  As long as they can fly they are good.  And fairly comfortable.  Unlike the earlier bomber crews.  Who flew in unpressurized planes.  For it is very cold at high altitudes.  And there isn’t enough oxygen to breathe.  So these crew members had to wear Arctic gear to keep from freezing to death.  And breathe oxygen they carried with them in tanks.  Pressurizing aircraft removed these problems.  Which made being in a plane like being in a tall building on the ground.  Your ears may pop but that’s about all the discomfort you would feel.  If a plane lost its pressurization while flying, though, it got quite uncomfortable.  And dangerous. 

Rapid decompression at altitude can be catastrophic.  And violent.  The higher the altitude the lower the air pressure.  And the faster the air pressure inside the airplane equals the air pressure outside the airplane.  The air will get suck out so fast that it’ll take every last piece of dust with it.  And breathable air.  Oxygen masks will drop in the passenger compartment.  The flight attendants will scramble to make sure all passengers get on oxygen.  As does the flight crew.  Who call in an emergency.  And make an emergency descent to get below 10 thousand feet.  Almost free falling out of the sky while air traffic control clears all traffic from beneath them.  Once below 10 thousand feet they can level off and breathe normally.  But it will be very, very cold.

Man’s Desire is to Go where no Man has Gone before and where no Human Body should Be

Space flight shares some things in common with both submarines and airplanes.  Like airplanes they can’t fly without fuel.  The greatest distance we’ve ever flown in space was to the moon and back.  The Saturn V rocket of the Apollo program was mostly fuel.   The rocket was 354 feet tall.  And about 75% of it was a fuel tank.  In 3 stages.  The first stage burned for about 150 seconds.  The second stage burned for about 360 seconds.  The third stage burned for about 500 seconds (in two burns, the first to get into earth orbit and the second to escape earth orbit).  Add that up and it comes to approximately 16 minutes.  After that the astronauts were then coasting at about 25,000 miles per hour towards the moon.  Or where the moon would be when they get there.  The pull of earth’s gravity slowed it down until the pull of the moon’s gravity sped it back up.  So that’s a lot of fuel burned at one time to hurl the spacecraft towards the moon.  The remaining fuel on board used for minor course corrections.  And to escape lunar orbit.  For the coast back home.  There was no refueling available in space.  So if something went wrong there was a good chance that the spacecraft would just float forever through the universe with no way of returning home.  Much like a submarine that can’t keep from falling in the ocean.  If it falls too deep it, too, will be unable to return home.

Also like in a submarine food and fresh water are critical supplies.  They brought food with them.  And made their own water in space with fuel cells.  It had to last for the entire trip.  About 8 days.  For in space there were no ports or supply ships.  You were truly on your own.  And if something happened to your food and water supply you didn’t eat or drink.  If the failure was early in the mission you could abort and return home.  If you were already in lunar orbit it would make for a long trip home.  The lack of food and hydration placing greater stresses on the astronauts making the easiest of tasks difficult.  And the critical ones that got you through reentry nearly impossible.  Also like on a submarine fresh air to breathe is critical.  Even more so because of the smaller volume of the spacecraft.  Which can fill up with carbon dioxide very quickly.  And unlike a sub a spacecraft can’t open a hatch for fresh air.  All they can do is rely on a scrubber system to remove the carbon dioxide from their cramped quarters.

While a submarine has a thick hull to protect it from the crushing pressures of the ocean an airplane has a thin aluminum skin to keep a pressurized atmosphere inside the aircraft.  Just like a spacecraft.  But unlike an aircraft, a spacecraft can’t drop below 10,000 feet to a breathable atmosphere in the event of a catastrophic depressurization.  Worse, in the vacuum of space losing your breathable atmosphere is the least of your troubles.  The human body cannot function in a vacuum.  The gases in the lungs will expand in a vacuum and rupture the lungs.  Bubbles will enter the bloodstream.  Water will boil away (turn into a gas).  The mouth and eyes will dry out and lose their body heat through this evaporation.  The water in muscle and soft tissue will boil away, too.  Causing swelling.  And pain.  Dissolved nitrogen in the blood will reform into a gas.  Causing the bends.  And pain.  Anything exposed to the sun’s ultraviolet radiation will get a severe sunburn.  Causing pain.  You will be conscious at first.  Feeling all of this pain.  And you will know what is coming next.  Powerless to do anything about it.  Brain asphyxiation will then set in.  Hypoxia.  The body will be bloated, blue and unresponsive.  But the brain and heart would continue on.  Finally the blood boils.  And the heat stops.  In all about a minute and half to suffer and die.

Man is an adventurer.  From the first time we walked away from our home.  Rode the first horse.  Harnessed the power of steam.  Then conquered the third dimension in submarines, airplanes and spacecraft.  We are adventurers.  It’s why we crossed oceans and discovered the new world.  Why we climbed the highest mountains.  And descended to the oceans’ lowest depth.  Why we fly in airplanes.  And travelled to the moon and back.  When things worked well these were great adventures.  When they did not they were horrible nightmares.  While a few seek this adventure most of us are content to walk the surface of the earth.  To feel the sand through our toes.   Or walk to the poolside bar in our flip-flops.  To enjoy an adult beverage on a summer’s day.  While adventurers are still seeking out something new.  And waiting on technology to allow them to go where no man has gone before.  Especially if it’s a place no human body should be.


Tags: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,

Outhouse, City Water, Sanitary Sewer System, Flush Toilet, Water Trap, Soil Stack, Sanitary Lift Stations, Weir Dam and Overflow Spillways

Posted by PITHOCRATES - April 11th, 2012

Technology 101

Before Indoor Plumbing People had to Walk some 50 Feet in Rain, Snow or Shine to go to the Bathroom

On the American sitcom The Beverly Hillbillies, Jed Clampett wasn’t sure if he should move his family to Beverly Hills after they found oil on his land.  He asks his cousin Pearl for advice.  She says, “Jed, how can you even ask? Look around you. You live eight miles from your nearest neighbor. You’re overrun with skunks, possums, coyotes, and bobcats. You use kerosene lamps for light.  You cook on a wood stove, summer and winter. You’re drinkin’ homemade moonshine, and washin’ with homemade lye soap. And your bathroom is fifty feet from the house. And you ask should you move!?”  Jed thinks about all of this and replies, “Yeah, I reckon you’re right. Man’d be a dang fool to leave all this.”  (This exchange begins at 11:40 on The Beverly Hillbillies (Season 1 – Ep. 1) The Clampetts Str).

On the American sitcom I Love Lucy, Tennessee Ernie Ford comes to visits the Ricardos in New York City.  On the day of his arrival, as he prepares to go to bed, he walks out of the apartment through the kitchen door with his suitcase.  Lucy and Ricky look at each other perplexed.  After a few minutes he comes back in and walks out of the apartment through the living room door.  After a few minutes he returns and approaches Ricky.  And whispers in his ear.  Exasperated, Ricky points and says, “Through the bedroom.”  In stunned disbelief Ernie says, “You mean it’s in the house?”  Ricky nods.  Ernie walks towards the bathroom and says, “Wait till I tell Mama about this.”  (See I Love Lucy Tennessee Ernie Visits).

Once upon a time, before indoor plumbing, people headed out of their house some 50 feet to go to the bathroom.  In rain, snow or shine.  To an outhouse.  Away from the main house.  Because of the stink.  And to keep their waste from seeping into the water table.  So their waste didn’t contaminate their drinking water.  So when they ever felt the call of nature they took that long walk.  Pushed open the door and squatted.  (Interesting fact: all outhouse doors open in for safety.  For if you were inside when a strong wind tipped the outhouse over you could open the door and then stand up, lifting the outhouse upright).  Or if it was a deluxe outhouse you may have sat down on some wooden planks.  Living like this was all well and fine when your nearest neighbor was 8 miles away.  Or in a suburban community with deep backyards.  For you could put your outhouse at the back fence.  Like your neighbor across the fence.  You can.  And some have.  But it’ll put a stink in the air.  And provide little privacy to do those most personal of things.  For when your neighbor sees the lady of the house walking back there it’s no secret what she’s going to do.

Flush Toilets are Possible thanks to City Water, Sanitary Sewer Systems, Water Traps and Stack Vents

Moving the bathroom into the house gave us true privacy.  So a lady could have a bowel movement without her neighbors knowing about it.  Two things made this possible.  City water.  And a sanitary sewer system.  These two things gave us the flush toilet.  A true marvel of engineering.  A porcelain bowl that holds a small amount of water.  Sitting on top of a pipe that ties into the sanitary sewer system.  A thing that makes the stink of an outhouse seem like a bouquet of roses.  Yet that stink doesn’t enter our homes.  Why?  Because of a simple thing called a water trap.  They come in a couple of shapes but typically have a u-shape somewhere in them.  Water enters and leaves at higher elevations.  Leaving the lower part always filled with water.  Providing a water seal between us and the stink of the sewer.  Thus preventing gases from entering our homes.  We build this trap right into our toilets.  On some models you can actually see the curly path the bowl drains into on the side of the toilet.

On top of the toilet base is a water tank.  With a valve and a float.  City water (under a slight pressure from the water plant) enters the tank through this valve.  When the tank is empty the valve is open and the water flows into the tank.  When the tank fills the float rises and closes the valve, shutting off the water flow.  At the bottom of the tank is a flapper valve.  When the tank is full of water the weight of the water presses down on this valve, sealing it shut.  When we flush the toilet we lift this flapper valve via a chain connected to a lever we operate with the flush handle on the toilet.  When we lift the valve the water in the tank can flow into the toilet bowl, washing the contents of the bowl into the pipe the toilet sits on.  As the water empties from the tank the flapper valve falls and seals the tank.  And with no water in the tank the float falls, opening the valve so water can refill the tank.

While the toilet tank fills because of the slight pressure they keep our city water under, the sanitary sewer system works under gravity alone.  All sewer lines in a building slope downward.  When they join other pipes they join in a ‘Y’ connection to make sure the new water entering another pipe enters flowing in the same direction of the water already in the pipe.  So as not to create any agitations or backpressure to the gravitational pull on the water.  To keep this water flowing in the downward direction.  If you have a basement in your house you can see a lot of this.  Downward sloping.  Y-fittings.  And you’ll also see one or two vertical pipes.  Soil stacks.  That other horizontal pipes run into.  Your sanitary waste (from floor drains, showers, sinks and toilets) flows to these soil stacks and down to a pipe under the floor that runs out to the sanitary line under the street.  If you follow these soil stacks up you’ll notice that they run all the way through the basement ceiling.  They in fact run all the way up and out through your roof.  Those little pipes you see protruding from your roof are stack vents.  These stack vents are critical in helping gravity work in your sanitary plumbing system.  By keeping a neutral pressure inside the pipes.  Making air pressure inside the pipes equal to the air pressure inside the house.  By equaling the air pressure on either side of the water traps the water stays in these traps.  If the system wasn’t vented the water wouldn’t stay in these traps.  As the column of falling water would compress the air below it creating a high pressure.  While creating a low pressure or vacuum above it.  Which would suck the water from the traps into the system above the falling water column.  And blow out the traps below the column.  Which would be rather nasty in the bathroom.  For it would blow raw sewage out of your toilet.  And onto you should you be in the bathroom at the time.

Sanitary Lift Stations have Backup Power and Failsafe Designs like Weir Dams and Overflow Spillways

At the beginning of all sanitary sew systems the pipes are their smallest.  Like inside a house where they connect to a floor drain, shower, sink or toilet.  As they join other pipes the pipe size increases.  To accommodate the increase in water volume.  The biggest pipe in a house is the one running to the sanitary line under the street in front of the house.  Which is a much bigger pipe as a sanitary line from each house connects to this line.  So it has to be big enough to handle all of the flow if everyone flushed their toilets at the same time.  Like at halftime during the Super Bowl.  And the pipes these ‘street mains’ connect to have to be even bigger.  For multiple ‘street mains’ connect to them.  And as more pipes join together they connect to even larger pipes.  And every one of these pipes is sloped downward to maintain the flow of water.  Pulled along by gravitational forces alone.  Which causes a problem.  Because continuously sloping bigger and bigger pipes downward will drive these pipes deeper and deeper underground.  Which can’t go on indefinitely.  As the ultimate destination is a wastewater treatment plant.  Which we typically don’t build underground.

So along the way we have to raise this wastewater so it can start its downward course again at a level closer to the surface.  We call these points sanitary lift stations.   Where a big pipe enters a wet well inside the station at a low elevation.  And exits the station at a higher elevation.  As water enters the wet well the water level slowly rises.  When the level reaches a certain elevation an automatic control system turns on pumps.  But not just any kind of pumps.  Some pumps with teeth.  That can grind up any solid waste that enters the sanitary sewer system.  From human waste.  To used condoms.  To feminine hygiene products.  And the myriad of other things that we shouldn’t flush down our toilets but do.  These pumps can pretty much grind up anything and spit it out into the discharge pipe of the station at a higher elevation.  So this wastewater can continue its journey to the wastewater treatment plant.

Some cities have a combined storm water and sanitary sewer system.  Which can tax the system during heavy rains.  For the water flowing into these wet wells will keep that level rising to a point the pumps may run continuously.  And should there be some damaging winds that take down the electrical grid these lift stations will throw-over to an emergency backup generator.  To keep those pumps running when we need them most.  To keep the water from rising too high in the wet well.  And the pipes feeding it.  For if those pipes fill up completely there will be no place for new water entering the sewer system to go.  Water will rise in manholes.  And out onto our streets.  Even out of our floor drains and into our houses.  As this would be a grave public health concern they often build failsafe protection in the sewer system.  The feed to the lift station will be a Y-connection.  Just past this will be a weir dam in the pipe.  A dam that blocks only the lower portion of the sewer pipe.  The pipe past this will run to some spillway into a river, lake or ocean.  If the flow in the pipe is too great for the lift station’s capacity it will spill over the weir dam and flow untreated directly into a larger body of water.  While this is bad it doesn’t happen often.  As it typically takes a ‘once in a hundred years’ rain to overtax a system.  And when it does there is so much storm water in the system that it greatly dilutes the harmful pathogens in the wastewater.

Our Sanitary Sewage Systems allow us to Draw Clean Drinking Water in the Same Room we Poop In 

Sanitary systems are gravity systems upstream.  As they get further downstream they get an assist from pumps.  As well as other powered valve and gates to redirect the water flow as necessary.  The bigger our cities get and the denser our city populations grow these active components become ever more critical to the gravity systems upstream.  So we provide backup power systems and failsafe designs.  We do everything possible to keep that wastewater flowing downstream and out of our homes.

Some of the greatest public health crises happen when these active systems break down.  For the power of gravity may influence our world a lot.  But the power of water is something to fear.  Especially when we lose control of it.  From tsunamis that overwhelm sewage systems in our coastal areas.  To 100-year rains that overwhelm our sewage systems in our interior areas.  To lift stations that fail and reverses the flow of wastewater in our sewage systems.  Worse yet is the discharge of raw sewage into our freshwater supplies.  That contaminate our fresh drinking water.  It doesn’t happen often but when it does it’s a health crisis of the first order.

But most times these systems work so well that we never think about them.  And can’t even imagine what life was like when you had to bundle up in the middle of winter and wade through thigh-deep snow to get to your bathroom.  Sitting on wooden planks in an unheated structure with the wind blowing through the slats.  Today we’re spoiled.  Not only do we not have to bundle up our bathrooms are heated.  And only a few steps away from us.  Because they are in the house.  Thanks to our sanitary sewage systems.  That can keep up with the waste production in our largest cities.  And allow us to draw clean drinking water in the same room we poop in.  If you really think about that it’s hard not to be as amazed as cousin Ernie was in I Love Lucy.


Tags: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,

Looking for the Higgs Boson, the so-called ‘God Particle’, is Real Science unlike Man-Made Global Warming

Posted by PITHOCRATES - December 17th, 2011

Week in Review

Fascinating stuff.  Theoretical physics taking us back to God?  Perhaps (see The search for the God particle goes beyond mere physics by Michael Gerson posted 12/15/2011 on The Washington Post).

The God particle — really the Higgs boson — still resists confirmation, though scientists at the Large Hadron Collider recently reported “tantalizing hints” of its existence. They also reject the notion that their search has anything to do with God, which is only technically true.

Modern physics can explain just about everything, except why anything has mass. The Standard Model of physics, which emerged four decades ago, employs an elegant mathematical formula to account for most of the elemental forces in the universe. It correctly predicted the discovery of various leptons and quarks in the laboratory.

But the equation doesn’t explain gravity. So the Standard Model requires the existence of some other force that seized the massless particles produced by the Big Bang and sucked them into physicality. The detection of Higgs bosons would confirm this theory — which is why scientists are smashing protons into one another in a 17-mile round particle accelerator and picking through the subatomic wreckage.

The Standard Model of Physics emerged 4 decades ago.  That’s 40 years.  And still they’re testing it.  Trying to find something that should be there.  But may not.  The Higgs boson.  The so-called ‘God particle’.  Which would really tie everything together.  They haven’t found it yet.  But, the good scientists they are, these physicists are still trying.  After 40 years.  Using real scientific inquiry.  And always being skeptical.

This is tough science.  Science held to a much higher standard than man-made global warming ‘science’.  Where they simply skip the experimental.  And announce their theory as fact.  You have to admit it saves a lot of time.  And lets government get down to business.  Taxing and regulating industry based on scientifically unfounded man-made global warming to replenish empty state treasuries.

Interesting stuff.  Be sure to read full Washington post article.  And follow the link to the Standard Model of physics.  Just because it’s so fascinating.  And really makes you think of the bigger picture.  And the tinier one, too.


Tags: , , , , , , , , ,