What is Critical about Mass: having enough to sustain a process

    There is a phrase used from time to time -- "critical mass". This phrase was initially used in regards to the manufacture of nuclear weapons. In order for a nuclear device to be able to start a fission (splitting atoms) reaction, there must be enough material that each splitting of an atom creates enough energy to allow for the splitting of additional (at least one more) atoms. So, the critical mass is enough radioactive material to allow for the process to continue once it is started.

   This concept is central to the creation of weapons because a bomb is created such that two, or more, amounts that are less than critical mass are kept close together -- when it is desired to detonate, the smaller amounts are pushed together to create the critical mass and the reaction can take place. A bomb is "clean" if it has the opportunity to split most of its radioactive material before spreading apart and "dirty" if it ends up spreading the radioactive material (not fissioned) into the surrounding area.

   This concept is also important with the design of nuclear power plants -- rather what NOT to do when designing a plant. A properly designed plant will maintain control of how much radioactive material is allowed to be near each other (with the addition of materials called "damping" rods which absorb excess energy). This is important not only for safety but also for the economic operation of the plant. If a plant is not designed this way then it is just a one-time-use bomb. Thus, nuclear power plants (though there may be other dangers) are almost impossible to cause nuclear explosions.

   One more term that is very important to this topic is the "tipping point". This is the very small range that exists between NOT having a critical mass and the amount reaching a critical mass. Just a bit more and it becomes critical. Remove just a bit and it becomes inoperative. Before the tipping point is reached, the process requires continued external energy to maintain progress towards the critical mass.

   All that is just a preamble to this blog [smile]. The concept of critical mass enters into many areas of our society -- political, economic, sociological, and so forth.

   One area of present interest and, which is entering the region of the tipping point, is that of electric cars. Electric cars have been around for quite a while (according to the Net, 1834). However, we do not see electric cars everywhere -- it is mostly internal combustion (gas or diesel) engine cars. Cars, by definition, are used for movement. This means that the source of their energy must be carried along with them. In the case of gasoline engine cars, this means tanks of gas. In the case of electric cars (actually, electric engine powered cars), this means batteries (or an awfully long electrical cord [smile]).

   Batteries have traditionally not been very powerful or very efficient. This continues to change and, although not specifically a critical mass, they are now reaching the point of efficiency to be able to be used more practically. (Note that the same idea is involved with the efficiency of solar cells for solar power.)

   Even with more efficient batteries, they still must be charged on a regular basis and the means to charge them must be close enough together (driving range) such that an electric car can go from one charging station to another. Additionally, the time needed to charge the battery must be relatively short or timed such that the charging can reliably be done at "non-use" times (such as night).

   So, the technology needed to have practical electrical cars on the roads requires three things: sufficiently efficient batteries to provide workable range, charging stations within that range, and technology sufficient to compete with other alternatives. This is now beginning to happen. We are close to the tipping point. The external energy causing us to reach this point has come from the dedication of various people who want the end result. Note that the same process happened to make the internal combustion car practical in the early 1900s.

   Another area of critical mass is concerned with political, or social, matters. Let us take the matter of the ability to vote, within the United States, for women. Within the democratic process, one group cannot grant themselves additional authority, privileges, or rights. They must be granted such by the people who already have that power. This means a process of change of thoughts and attitudes. The energy to achieve that came from dedicated people who worked towards that goal. They achieved critical mass when enough of the existing authorized voters were convinced that women should be granted the right to vote.

   There are many areas where the ideas of a tipping point, and critical mass, are important. They are both involved in areas of change. The change may be a chemical, or physical, process. The change may be a social process. The change may be a political process. But they each have stages and move from one to another by approaching the tipping point, reaching critical mass, and effecting the change.

    What areas of critical mass do you see approaching and which ones do you see from the past?

The Interconnectivity of Things : work

    A popular topic nowadays is the Internet of Things (IoT). This talks about tangible devices that are interconnected via the Internet. I might discuss that someday. However, IoT is really a subset of the interconnectivity of Things (InOT). And that interconnectivity applies at many levels. Today, in continuation of my recent blogs on economics, I thought I would talk about how work/jobs interconnect.

    One way to examine this is to put forth a possible change to the economy -- a shift from private transportation to public transportation (to save space later, let's call this "the Shift"). How would this affect the economy and how would it affect jobs and work?

    The first thing that can be done is to list the things that are associated with private transportation.

1. Roads
2. Parking Lots (including driveways and garages)
3. Gasoline (assume have not migrated to electric cars)
4. Consumable parts (tires, windshield fluid, batteries, etc.)
5. Car distribution (including sales and transport)
6. Car manufacturing
7. Car repair
8. Car maintenance (including washing, upgrades, and so forth)
9. Car disposal

    I am certain that this is not an exhaustive list and, as we will see, each item can be broken down into many sub-items. The Shift is also not a truly radical shift as most things associated with private transportation also exist associated with public transportation. Thus, it is a shift for reduction rather than elimination and creation.

    Let's look at the first item on the list -- roads. First thing is that roads occupy space -- lots and lots of space. The Shift would not eliminate the need for roads but probably no roads would need to be more than 2 lanes (one each direction). In fact, many low usage roads could probably be a single lane with pull-over areas (similar to low-traffic roads in Europe). As a conservative estimate, let's say that, with the Shift, we could reclaim 80% of the land currently used for roads. (Skipping to item two, we can also probably reclaim 95% of the space needed for driveways and garages.) It also reduces the size needed for bridges and tunnels. What can this space be used for? Parks, farmland, recreation, pasture -- whatever space is presently used for.

    One website indicates about 18,000 square miles (about 0.6% of the land area) are used for roads in the US. That site argues that that isn't very much but I would note that there are 9 states in the US that are each less than 18,000 square miles and it would be the same square miles as Rhode Island, Delaware, Connecticut, and New Jersey combined. The Shift would reclaim about 15,000 square miles or a little more than the size of Maryland.

    Space was the first part of the first item. Roads also includes heavy construction equipment, labor (about 140,000 workers in the U.S.), concrete and asphalt manufacture and transportation, bridge and tunnel design, and so forth. Let's say that there are 200,000 jobs associated with roads and the Shift would eliminate the need for 50,000 of them. This means that 150,000 people in the US would need to find different jobs.

    And this is just the very first item associated with the Shift. Every item above involves jobs, land use, energy use, and so forth. As a conservative guess, the Shift would cause the need for a million people to find new jobs.

    So, yes -- many reasonable people would like to see the Shift, but resistance to the Shift is not just an automatic resistance to change. It is also based on the economic turmoil to families and economic infrastructure.

    Once upon a time, I suggested a tool that would make analysis of such changes as listed above much easier. In my next blog, I will go into more detail of the design of such.

    In the meantime, what effects do you see would come out of the Shift and would it be worth it?