Crick, Watson, Franklin and Szillard

James Watson died yesterday.  He was the last of the people responsible for discovering the Double Helix structure.  Watson and Francis Crick won the 1962 Nobel Prize in Physiology and Medicine for their discovery, which is one of the most important of all time.

There are two other people who deserve mention.  Most people are aware of the previous work done by Rosalind Franklin, who unfortunately died 1958 but would have certainly deserved a share of the prize. 

The other important contributor was Leo Szilard.  Szilard's most famous achievement was realizing that nuclear decay is caused by a neutron chain reaction, and that by manipulating the density of neutron emitters, you could control the rate of nuclear fission, right up to, and including a runaway explosion, which became known as the Atom Bomb.  Fermi's experiments a few years later led to the first Nuclear Pile in 1938, and in 1945, the first Atom Bomb.  Szilard intentionally kept his idea for the bomb secret because he was terrified of the Nazis getting the A-Bomb first, but he and his friend Einstein wrote a letter to Franklin Roosevelt, which motivated the creation of the Manhattan Project.  Szilard and Einstein were specifically kept out of it to try to keep the Nazis from pursuing the idea.  Turned out Hitler regarded this stuff as "Jewish Science" and had effectively blocked progress in his country (Szilard and Einstein, along with Openheimer, Fermi's wife, and many of the others involved were Jewish), but he had no way of knowing that, having fled to England in 1933 and America in 1938.

 Szilard's contribution to the discovery of DNA were severalfold.  He invented the electron microscope in 1928, which made it possible to see some detail in chromosomes for the first time.   And it was he that devised the XRay diffraction technique which Franklin and others would use to work out the physical structure of DNA.

I regard Szilard, who died of a heart attack in 1964 at age 66, as perhaps the greatest scientist of the 20th century, in a league with only Einstein, Tesla, and Louis Alvarez.  

Breakthroughs vs Debugging

When considering an engineering project, there are three potential barriers to succeeding:

Political/Economic.  These are things like funding and NIMBYism.  A store that wouldn't mind having your train station across the street may be upset if it's so close it requires them to find another location.  Such considerations need either to be bought off or taken by eminent domain. Enough such problems may make it impossible to implement your project with the funding you have, but are solvable problems, at least in theory.

Debugging.  It's rare that the first design of anything very complicated succeeds.  Some debugging or redesign is nearly always necessary.  Oversights, mistakes, shortcomings, misunderstandings, etc., always occur. The engineering or construction time to fix it costs money and if there's not enough available, the project may fail, but if the problem is one of debugging, it is a solvable problem.

Breakthrough required.   Some ideas are simply contradictions of the laws of physics.  For example, a nineteenth century scientist likely thought that traveling to the stars was just a matter of going faster and applying more energy.  But in the early 20th century it was discovered that the speed of light is an absolute limit and that the energy required to get even close to it was impractical.  To get to the nearest star will take more than a human lifetime.  Unless some breakthrough, like Star Trek's "Space Warp" technology is discovered.  It's conceivable but nobody has even the first idea of how to do it.

So, for example, Hyperloop (transit in an evacuated tube near the speed of sound) does not require any breakthroughs to succeed, although there may be some.  All the technology required is fully understood, in at least a general way.  There may be some friction from politics and engineering, but with enough determination, they are all solvable.

A space elevator (a cable anchored to a geosynchronous satellite) is mostly straightforward engineering, except for one thing: the cable needs to be strong and light enough that it doesn't break under 22,000 miles of its own weight.  No fiber presently known can do this.  There are some breakthroughs on the horizon that might succeed (e.g. carbon nanotubes), but this is impossible until there is an actual breakthrough.

Mass of the Solar System

The Sun is 99.8% of the mass of the solar system.  Jupiter is about 70% of all the mass in the solar system that is not the sun.  Ganymede, the Moon, and all the dwarf planets and moons are all less massive than Mercury, most by a lot. The total mass of the asteroid belt and all the comets is around 3e21...way less.   It's remotely possible that there's something big in the Oort cloud, but unlikely.

The lightest brown dwarfs are believed to mass abut 2.5e28 kg, roughly 13 times heavier than Jupiter.  The lightest actual stars are believed to mass about 1.5e29, about 75 times the mass of Jupiter. 

The solar system is the sun plus little stuff.  There will never be another sun in the solar system, unless it captures a passing star.


mass in kg, diameter and distance in km

Name	Mass	Diameter	Distance from Sun
Sun	1.9891e30	1.39e6	0
Mercury	3.3e23	4889	5.7e7
Venus	4.87e24	1.20e4	1.08e8
Earth	5.97e24	1.27e4	1.50e8
Mars	6.42e23	6779	2.28e8
Jupiter	1.90e27	1.40e5	7.80e8
Saturn	5.68e26	1.16e5	1.43e9
Uranus	8.68e25	5.01e4	2.87e9
Neptune	1.02e26	4.92e4	4.5e9
Planets	2.68e27

Technical Errors in "The Martian"

Andy Weir's The Martian is one of the most technically accurate science fiction stories of all time, although it's not perfect.  I just re-watched the excellent movie, which followed the book unusually well.  This critique is based on the movie:

Martian atmosphere is about 1/10th that of earth.  The wind would not carry all that much energy, even if it's blowing 200mph, and it's hard to imagine it knocking over the MAV or carrying enough sand that the sand might do it.  The pictures of dust devils taken by the rovers are scrawny little things.  It is plausible that it might cause flight in lightweight things that aren't fastened down properly, such as satellite dishes, so the incident that seems to have killed Watney is remotely possible, but the crew would have simply hunkered down and ridden it out.

The Aries 4 MAV is already on Mars, 4 years ahead of its use.  Mission planners expect it to still be standing when the Aries 4 mission arrives, despite frequent sandstorms that apparently can knock a MAV over?

It is inconceivable that a month long surface mission wouldn't have several redundant transceivers that could quickly reestablish communication between a marooned spaceman and earth, even if the primary went back into space with the rest of the crew.  For example, I'd think each rover would have had a high gain antenna analogous to the one on Pathfinder--about a foot in diameter: a phased array with relatively low bandwidth and only needs to be aimed in the right general direction to obtain maximum gain.  Not quite enough bandwidth for SDTV video, adequate for voice, and more than adequate for TTY and still photography.

It doesn't make much sense to have a specialist botanist on an early Mars exploration mission.  A different specialty scientist who happened to have a background in botany, perhaps, but not a specialist.   Had I been in Andy Weir's place, I'd have had Watney have been a farm boy who grew up to be a scientist (geologist perhaps?) and astronaut.  Growing potatoes in martian soil and human manure is pretty basic farm stuff.   I'm pretty sure I could do it and I'm not a farm boy or botanist at all.

Watney manages to keep his potato harvest healthy for over a year after the breach, in the same atmosphere he's living in.  It's probably impossible to keep bacteria and fungus from his own body from infecting them.   I can't keep potatoes for more than a few months, unless I freeze them.    The originals from earth probably survived this way too: vacuum packed and frozen.  He'd have protected his harvest exactly this way, and they would have survived the HAB breach, and he could have started up his garden again.

The HAB is soft skinned.  This is plausible as a covering for non-human stuff and even short term habitation, but unless there is some sort of magic radiation shielding developed between now and then, totally implausible for a month long habitation.  The astronauts might survive, but probably not for long enough to make it home.  I think the only real answer is to put the dwelling underground.

The same point holds for the Hermes interplanetary ship.  They got a lot right for the Hermes design, but there's no evident shielding, which should probably be ten feet thick or more around crew areas.

A great deal of space on the Hermes is given to human-occupied areas in microgravity.  I would doubt there would be many--airlocks and docking berths--but you wouldn't expect the astronauts to need to go through them very often.

The calculations Rich Purnell needs to solve to work out the maneuver are mathematical and demand high precision, but are not especially complex.  He wouldn't need a supercomputer to solve them.  The laptop on his desk would be ample.  (had he been doing it in 1966, he might have needed a supercomputer, but the PC I'm using to type this is about 300 times faster than a CDC 6600, the fastest machine of 1966).   Even if he did need a supercomputer for some reason, he wouldn't have needed to leave his office to do it.  (that said: I met an "Orbits" guy when I worked at Lockheed Missiles and Space.  The eccentric Rich Purnell character is totally plausible.)

The MAVs (both Aries 3 and 4) are entered through an airlock in the middle of the floor.  Underneath that floor is the second stage of the ascent rocket and underneath that is the first stage.   Wrong.  The astronauts would climb up the MAV on the outside and enter through a door in the side.

When Watney enters the MAV with his EVA suit on, he enters through this same airlock door, and closes and fastens it.  It is obviously a big heavy thing.   I'd think it'd have been among the first things to be tossed overboard.

The nose cone is shown sliding right past the MAVs attitude control jets.  Watney is going to need those.  He'd have figured out some way to guarantee not breaking them.

I don't understand why they needed to blow the airlock door.  They can override other safeties, why not that one?   It does make a fun plot element though.

We see personal laptop computers from Commander Lewis, Johansen and Watney, and we can be sure the others left theirs behind too.  Why is it that only Lewis has recorded music on hers?


addenda:
Water has recently been discovered on Mars, trapped in rocks, plentiful and reasonably easy to obtain.  This spoils one of the central plot elements, although Weir couldn't have known that when he wrote the book.

I read Weir's latest, Artemis.  It's almost as good as The Martian.  

Converting Heat to Rotary Motion

This is the flow of all energy used by the US in 2015, as calculated by Lawrence Livermore Labs.

There's a tremendous amount of useful information here.   For example, wind and solar are now a noticeable part of the grid, and electricity is contributing a useful amount to transportation.

But the biggest thing is the amount of rejected energy.  That's 60.6% of all energy that's being consumed by the US that's being lost due to inefficiency of some sort.  80% of this and maybe more is coming from two uses: electricity generation and transportation.   What they have in common is that they're using the burning of something to convert heat into rotary motion.

Here's an example: a conventional car contains an internal combustion engine, which works by spraying a mix of gasoline and air into a cylinder and setting it alight.  The resulting explosion pushes the cylinder against a crankshaft which connects to the wheels of the car to make it move.  This conversion is at best about 33% efficient--most of the energy--and with it the pollution, CO2 and other stuff, is lost to heat and noise, without producing forward motion.    The same thing is happening when burning coal or gas to produce electricity: it heats something (either boiling water or the natural gas exhaust itself) so that it can be used to power a turbine, which is connected to a generator.  The theoretical peak efficiency of such a process is about 60% and the reality is a lot worse: the very best electric plants operate at about 40% efficiency.  The rest is waste heat.

If, on the other hand, the heat is the ultimate product, for example burning stuff to make heat in a furnace, it is much more efficient.  Modern furnaces are over 90% efficient.  The blast furnaces used in steelmaking are similarly efficient.  

Wind and Solar suffer different inefficiencies, but the waste doesn't end up in the atmosphere as CO2 or smog, and it doesn't consume a resource that takes a hundred million years to replenish.  Electricity can be used to make rotary motion much more efficiently than the reverse, so it's useful for a large fraction of the needed activity in industry and transportation.   according to the chart, .03% of electricity is used for transportation.  This includes electric cars like a Tesla or Leaf, and Trolley Buses and Electric Trains like on the northeast corridor, but does not include hybrids like the Prius or a diesel-electric locomotive.

It seems to me this is fairly low hanging fruit.  60% of our energy production is lost to the inefficiency of using heat to make rotary motion.   The second law of thermodynamics says we're doomed to lose some, but to get half of this back seems relatively straightforward.  Converting half the cars on the road to electric will save around 10 Quads of rejected energy.  Converting half the gas and coal power plants to wind and solar will save  around the same.

Pseudoscience Ascendant

I just returned from 8 days in my hometown, Cupertino, California.  Cell phone and cellular data reception there continues to be terrible, and if I use my phone much, the battery dies in a fraction of the time it does in more sensible places.   The home of Apple, HP and countless other high tech innovators, has very few cell towers, and these companies have been forced to implement their own private cell networks.  Here's the reason.  They have it exactly backwards.

The WHO report cited is essentially a sop, admitting that it's remotely possible that this could be a problem, just to get these nincompoops off their back.   There is no credible evidence that low level gigahertz radio causes cancer.  None.  Very high power, tuned and focused radiation can cook things though.  Microwave ovens are tuned to the frequency of water. They're shielded, but by staying a few feet away, even if there's a breakdown, you can stay safe. Powerful radars have been known to kill bugs and birds that flew too close.  Not by cancer though, by boiling the water in them.

But let's pretend that there was a problem.  Digital cell phones adjust their power output based on how far they are from the cell tower.  If they're far, they increase power, if they're near, they reduce it.  This has a bunch of advantages.  First of all, it saves a lot of battery power if they don't have to use it.  More significantly, it increases network capacity.    Each logical channel is only used up for as big an area as the power being used can reach.  The same channel can be used by another tower/phone pair if they're out of range.

But the notowerinschoools folks have this exactly backwards.  By keeping the towers far from the students, they are FORCING all cell communications to occur at high power.  The transmitter that matters is not the one in the tower.  The inverse square law makes it of little consequence to anyone more than a few dozen feet away.  The transmitter that matters is the one the kid is holding up to their ear.  If the tower 5 miles away, it's transmitting at high power.  It's unlikely to cause cancer, but it might be boiling the kids brains a little bit.  From less than an inch away.   The closer the cell tower is, the less power the mobile phone needs to use to transmit.  Unless you ban the cell phones completely, you are achieving exactly the thing you were trying to prevent.  I wonder how a cell phone ban would go down in the schools of Cupertino...not.

Idiots.

Addenda 3 Jan 2017

 There's a new cell tower in Cupertino near city hall that went on line in the spring. Cellular is now /much/ better there.

Hydrogen Cars

Hydrogen fuel cells sound to some like a promising technology: it allows an electric car which can be refueled quickly and its only emissions are water.  But it's up against some laws of physics that make it tough to be practical.  The main one is that the energy density of hydrogen is very low.  Liquid hydrogen has an energy density 1/4th that of gasoline.  This means to get a car with the same range, you'd need a gas tank 4 times as large.  But liquid hydrogen is incredibly expensive and the tank would be impractical.  Carrying it at much higher than about 3000 PSI (roughly what is used in a SCUBA airtank) is probably impractical, but at that pressure, the energy density is about 1/20th that of gasoline.  To replace the the 11.9 gallon fuel tank and internal combustion engine in a Prius with fuel cell and a 3000 PSI hydrogen tank and get the same range would take a tank of around 250 gallons.  This is a volume of about 33 cubic feet.  This is roughly the entire interior volume of the Prius....if you take out all the seats!

The bottom line here is that without some significant technological breakthrough (for example extremely high pressure tanks, or some scheme that where the hydrogen is dissolved in some other material at much higher than 3000 PSI equivalent), a hydrogen car isn't likely to have much range.   A bus or truck is a different story: it has a lot more places to put the tank(s).   Hydrogen does have one big advantage over gasoline or battery electric: the mechanism, tank, fuel (even 250 gallons), fuel cell and electric motor, is a lot lighter.  This may help with mileage to some extent but nothing like enough to give it the range we've come to expect.

Nevertheless, Toyota has just announced the Toyota FCV, a Camry-sized Hydrogen fuel cell car to be put on the market in 2015, which they claim has a 300 mile range and can be refueled in 3 minutes.   I'm skeptical.   None of the pictures show the interior or even say how many passengers it carries.  It pretty much has to be a bunch of hydrogen tanks on wheels, with very little room for the occupants.


In most places the cheapest way to make hydrogen involves heating natural gas with steam to split the hydrogen from the CO2.  This produces as much CO2 as burning it (even more if you burned something to produce the steam) and is at least as bad for the CO2 levels in the air as other fossil fuels.  It is NOT a green fuel, it is a fossil fuel, with all the problems that come from it.  The CO2 isn't coming out of the tailpipe of the car, but just as much (more actually) is coming out of the plant.

In some places, where you have extremely cheap electricity, you can make hydrogen with electrolysis of water. It takes more energy to do this than you will get out of it, so it makes the hydrogen a sort of storage battery, but because of the ease of refueling and the light weight may give it an advantage.  Iceland, with abundant geothermal electricity, is such a place, and as the whole island is only 250 miles across, a low range car is pretty practical.

Hydrogen is no more flammable than gasoline, although if punctured, a high pressure tank would spray a stream of hydrogen until it's exhausted.  If it ignites, that's potentially a very hot, very focused flame. 

Centrifugal Spaceships

Back when we still thought we were going to spend the next 50 years exploring space, one of the popular ideas was to implement artificial gravity by putting passengers and crew into a big centrifuge.  Wernher von Braun, Chesley Bonestell, Arthur C Clarke and many others included giant, rotating space stations as part of their imagery.   These guys understood that lack of gravity was a real problem and thought dealing with that was critically important.  As real experience with humans in space as been accumulated, the consequences of "microgravity" have been recognized to be even more serious than they'd feared, leading to bone loss and other problems.  So why is it that we haven't built spinning space stations?

The reason is that there turned out to be lots of other problems that were equally, or maybe even more serious.  Simply getting stuff up there has proven incredibly challenging, and the economics have worked out that many, small, unmanned satellites provide a much better return than putting humans up there.  Secondly, the reality turned out to be that the political advantage gained by the space race was fairly limited to "beating the Russians".  Once that was accomplished, there was really very little popular support for the space race.  So there was little support for big ideas like the space station in the image above (by Bonestell), which inspired Arthur C Clarke and Stanley Kubrick in their movie 2001: a Space Odyssey.  The space station we've actually got, 12 years after 2001, has a pressurized volume of 29,600 cubic feet--about what 3700 square feet of building have.  Much of this is filled with equipment, so the living space is really no more than that of a moderate family house.

If all that space were organized into a ring like the one above-12 feet wide by 8 feet high, the ring would be a mere 64 feet in diameter.  To spin it fast enough to make a 1/6th G (lunar gravity) would take 7RPM, or fast enough to make 1 G, it would take 17RPMs.  Ridiculously fast, and not really practical if you're trying to take a look outside or dock a spaceship.  To get it down to the stately speeds we saw in "2001", it would have to be a half mile or more in diameter.  At that size, lunar gravity can be simulated with just one RPM.  The centrifuge inside the "Discovery" spaceship, where we first met movie astronaut Frank Poole jogging, was about 50 feet in diameter, so it would have to spin even faster.  I'm sure for really long trips, like the one they're on in the movie, space ships would have to contain such centrifuges.   I think that's about the smallest practical human centrifuge though.    Eventually, we'll have big, kilometer diameter or bigger space stations, and I have great hope for O'Neill Cylinders some day in the future.  But not for a while yet.

Cell Phones on Airplanes

It's against FCC regulations to use a cell phone on an airplane.   Most people seem to think the reason is that they're afraid it'll interfere with the navigation of the airplane.   Here's the FCC's policy statement on the subject.  Note in particular the second statement: they're worried about interference with the ground.

To understand this, it's important to understand how a cell phone works.  Each phone has a radio transmitter/receiver, aka transceiver. It's capable of being tuned to any one of (depending on protocol) dozens or hundreds of channels.  Whether it's digital or analog, 3G, 4G, TDM, packet, etc., what exactly constitutes a channel is immaterial to the issue.  What's important is that there are a limited number of them.

The ground part of this consists of a network of transceivers mounted on poles or other high places, called cell towers,  which can tune to the same channels.  They are organized into cells, which is a region on the ground using wires or microwave links to connect to each other and the rest of the phone system.  Each cell tower can use, at most, the number of channels in the protocol.  Phones are low power radios and they actually reduce power so that they can't be heard by more than one or two cell towers at once. Because any bandwidth a phone uses must be reserved by every cell tower that can receive the signal.  (this is not strictly true--there's some collision recovery in several of the digital protocols--but collisions reduce bandwidth, so the essential problem remains.  for simplicity, let's pretend it's all channels and ignore packets and collisions and such)

Most of the time, most phones are not in use--they have a handshake with their local tower so the system knows which phone to ring, but this doesn't take much bandwidth.  Phones that are in use use a lot of bandwidth.  If an area has a lot of phone traffic--a big building for example, they'll put extra towers in to adapt.

But it's important to recognize the two dimensional design of the network.  Most of the time you're fairly close to the center of a cell.  you use two cells only when you're near the border of both.  But if you're up in the sky, you're a lot farther from the closest cell, and the second closest might be only a little farther yet.  Worse, there might be several others that are still close enough that any bandwidth you use on your phone must be reserved for all the cells.  In a dense city and a plane at 10,000 feet, this could be a hundred cells or more.

Now imagine that a plane is flying over our group of cells, carrying 100 passengers who simultaneously want to call their spouse or client or whatever, telling them the plane is about to land, time to come pick me up at the airport.  They've used 100 channels in every cell within range--which could be a band 10 or 15 miles wide and 50 miles long, under the landing pattern, which is usually in a big city.  Not only that, there's another plane coming along a minute or two later doing the same thing, with an effect that's overlapping the first plane.  Two or three such planes could exceed the entire capacity of the entire group of cells.

So they ban it.  If one or two people call, it's no big deal; it's stealing those two channels from all those cells, but they have enough capacity they can handle it.  If half of them leave their phones in ground mode by mistake, there's so little bandwidth used it hardly matters.  It's only if a lot of them are using a lot of bandwidth simultaneously that it's a problem.  Adding more cell towers doesn't solve it: they'd be in range too. what does solve it is a cell repeater on the airplane, which uses a different protocol to talk to the ground.  FCC is happy to have people think it'll cause interference with the airplane they're on, because that'll keep them from cheating.

Similarly, the flight attendants don't have the time to figure out which electronic device might cause ground interference and which is harmless.    The fact is that most are harmless, although there is a tiny chance that one of them might cause a bunch of RFI, and a real problem, either because it's non FCC compliant or because it's malfunctioning.  The one they don't recognize might be the one that causes the problem.  Simpler and safer to have a single rule and ban them all.

Rainbows and Green Flashes

I've seen the "green flash" three times--all at sunset, from west coast beaches:  Once from Cannon Beach, in Oregon, Twice from Pajaro Dunes, in California, all in the winter.  There's a reason for this, as I'll get into later.  Many people are skeptical that it's a real thing.  It is, but things have to line up just exactly right to be able to see it:

You need to have clear viewing all the way to the horizon and past it--no clouds, no haze, especially no mountains.  Typically these conditions happen only when it's been raining and it's cleared up just an hour or two before sunset.  it helps if there's a little bit of haze right at the horizon, but not much.

The water needs to be warmer than the air.  This is why it tends to be a winter phenomenon.  The green flash is a member of the broad class of optical phenomena called "mirage", which results from layers of air being heated differently, resulting in them refracting different colors differently.  The bottom level of air needs to be quite a bit warmer than the air at eye level, which really can only happen if it's being heated by water.  Because blue and green are scattered more than red, sunsets tend to look red.  But there's a moment that the red light is all passing above your eye while green is coming your way.

The reason I think rainbows are similar is because they take a combination of several things to make them happen:  it needs to be clear enough that the water vapor is well lit.  But rainbows aren't very bright and it's hard to see them against a clear blue sky: there needs to be something behind.  it's usually in front of clouds or something else that's darker than the sky.  The primary rainbow is about 2 degrees thick and it's about 80 to 84 degrees wide.  Rainbows are the result different colors of light being refracted differently by water, but all being reflected together inside drops of water.   (To see all of it with a 35mm camera, you need a 19mm lens.  usually you can't see all of it.  to see all of a double rainbow, you need a 13mm lens.)

My favorite rainbow was when I was driving almost due north late on a winter afternoon.  I was at the southern edge of a storm--behind me was well lit, but the hood of my car was in light rain.  the rainbow appeared to be around the hood of my car.  Todd Newman was with me and we both saw it, but we didn't have a camera convenient and it didn't last long.

Steam Engines in Space

Much current power generation is done with steam.  Water is confined in a "boiler" and exposed to some heat source (burning coal, nuclear fission, concentrated solar energy, etc.) and boiled.  This produces steam, which is passed through a pipe to a turbine or reciprocating piston(s) to produce rotary motion.  Usually this is used to power a generator, but sometimes the rotary motion is used directly--a steam locomotive for example.

An important but subtle component of a steam locomotive is what's called the "steam dome".  This is a dome on top of the boiler, where the steam collects.  It relies on gravity--water stays in the boiler, while the "dry" steam floats on top and in the dome.  It's important to keep water out of the steam tubes and pistons: it cools the steam, reducing pressure, and if there's enough of it, can prevent the piston from moving and break something.

As far as I can tell, conventional steam locomotives need gravity or something like it (e.g. centrifugal force) to operate.  There are heat engines which do not require this separation of dry steam, such as the Stirling Cycle, so it's still possible to produce rotary power in space.  It's also possible to make a direct ejection steam rocket which could operate in zero-g.

Entropy

Entropy is a measure of the inefficiency of thermodynamic actions.  You cannot convert all the energy of a thermodynamic process.  It's lost somewhere--heat, friction, noise, radiation, useless motion, etc.  That loss goes under the general term "entropy".  Not only is there entropy in every process, but it's impossible to even measure it directly.  You can only infer that it's there by measuring what you do get back. The laws of thermodynamics, roughly speaking are:
1: Heat can only move from a warm body to a cold one, not the other way.
2: Every thermodynamic process has positive entropy.

Or as my friend Pete Darnell puts it:
You can't get ahead
You can't break even, and
You can't quit the game.
I suspect it's not original to Pete but that's where I first heard it.

One of the consequences of this is that perpetual motion machines are impossible.  If you think you're seeing one, it's because there's something you're missing.  It might be a hidden source of input energy, or it might be that the process is so efficient that it takes longer than your patience to use up the energy it has stored, like a top that can spin for an hour.

I first learned about entropy when at about age 12, I read Isaac Asimov's story "The Last Question", which is about the end of the universe. Entropy is sometimes called "Heat Death" because the losses from things like engines are often manifest as waste heat, but it's really more accurately called "Chaos Death".  It's possible to recover a lot of the heat from various processes and use it for something else--this is sometimes called co-generation.  For example, a blast furnace used in making steel might also power a turbine with its considerable waste heat.   But it's impossible to get it all.   Presuming that the matter and energy in the universe are finite (that's not completely certain), it will eventually all be lost to entropy.  It may take a trillion years, but it will happen.

When I was in my early 20s, I had a very powerful realization, that chaos, including entropy, is a major part of everything that goes on.   This is a good thing, because among things, it gives us a lot of freedom and flexibility, and frankly, fun.  Very little in the world is black and white, not even black and white.  Without chaos, we'd be committed to a predetermined path through life.

<I think this is unfinished but that'll do for now>