How Predictable is the Future of Solar Energy?

Reference: JD Farmer and F Lafond, How predictable is technological progress? Research Policy, 45(2016):647-665, www.sciencedirect.com/science/article/pii/S0048733315001699

                       Farmer and Lafond's Figure 1. 

Is solar exponential? Nuclear? Coal?

Problem: Why Moore's law?

Answer (partial at least):

Next year's value is often this year's value + a percentage

Why?

Analogy: what is the rate of water evaporation?

But the percentage increase is very noisy

• Dr. S invents a new advance

• Recession holds back progress

• Companies merge/go out of business

• Government policies do whatever

• Etc.

How to model that along with %/year increases?

• Geometric random walk

• This captures:

• The trend (geometric - discretely exponential)

• The noise (random walk)

• Add in autocorrelation

• Models that the noise changes slowly

We can now figure:

      the distribution of possibilities at a given future time

• See Farmer and Lafond, equations (1) through (16)! ☺️

                   Farmer and Lafond's Fig. 10. 

What is the probability of being below the dashed line?

What is the probability of prices stalling until at least 2028?

Image source: https://en.wikipedia.org/wiki/Standard_deviation

Remember the Cone of Uncertainty concept?

Farmer and Lafond's Fig. 11: 

"Probability that solar photovoltaic modules become less expensive than a hypothetical competing technology C whose initial cost is one third that of solar but is on average not improving..."

Cognitive Enhancement

Drugs that enhance normal mental functioning are possible

Stimulants often improve performance

You can call it "doping"

Just like in sports

Maybe we wish it weren't so!

Substance, etc.	Main action	Mediating mechanism
Nicotine	Increase concentration (etc.)	Increase acetylcholine (etc.)
Strychnine	Stimulant	Block glycine receptors
Caffeine	Stimulant	Decrease tiredness
Hydromel (unfermented)*	Increase available energy	Raise blood sugar
Sage	Improve memory	Inhibit cholinesterases
Chewing gum	Improve memory	Uncertain
Modafinil (Alertec, Provigil)	Maintain alertness	Anti-sleepiness
Alcohol	Enhance creativity	Improve incubation phase
Methylphenidate (Ritalin)	Improve focus	Stimulate central nervous system
Amphetamines (Adderall)	Improve focus	Stimulate central nervous system
Piracetam	Enhance cognition	Increase brain metabolism
Hydergine (ergoloid mesylates)	Enhance cognition	Increase brain metabolism
Donepizil (Aricept)	Improve memory	Inhibit cholinesterases
Cortactin	Enable neural plasticity	Circumvent calcain biomolecules
Magnesium threonate	Enhance learning & memory	Increase synapse plasticity
Insulin-like growth factor 2	Improve memory	Enhance memory consolidation
Metformin	Improve learning	Stimulate neurogenesis
Exercise	Enhance cognition	Stimulate neurogenesis
Afternoon napping	Improve learning	Clear hippocampal input queue
NgR1 antagonist	Enhance neural plasticity	Reduce demyelination; increase synapse turnover
Fish, except fried	Uncertain	Increase brain tissue volume
Klotho	Enhance cognition	Side effect of life extension
GLYX-13	Improve memory	Acts on brain’s hippocampus

Table 1. Some cognitive enhancement substances and activities. (Not recommended for use nonmedical use)

There are basically only a few strategies for cognitive enhancement

• Stimulation. 
• Coffee or any other stimulant makes the brain, or parts of the brain, work harder.
• Neuroplasticity. 
• Learning requires updating the neural connections, so ways of making these connections change faster can speed learning.
• Augmentation. 
• Brain augmentations could work via anything from chips inserted in the brain to hats with embedded electrodes.
• Bootstrapping. 
• If you learn something, then you are smarter. Called “education,” this is not the “easy way” to enhanced cognition — but in the long run may be the most effective.
• Health care. 
• Innumerable health related issues, mental and physical, can reduce cognitive performance. Fixing them will thus improve cognition.

Let’s look at some examples next.

Transcranial Electrical Stimulation (TES)

• Pills take at least a few minutes

• Raw electricity...

• Fast. The call it "juice" for a reason

• Electricity applied directly to the head! 

• Typically 1-2 mA

• Electroshock therapy: around 800 mA

• In 1883,⁵ Sylvanus Thompson described connecting a battery to the forehead to cause a “wild rush of colour” 

• He did not claim to have tried it himself
• but he didn't say he didn't

Numerous studies have shown TES to be able to improve performance in normal people on a wide variety of cognitive tasks related to language, arithmetic, learning, skill acquisition, and planning. 

You can get TES devices commercially with a doctor’s prescription. 

You can even build your own TES machine on the cheap from do-it-yourself plans.

DBS:

For more focused application, insert electrodes into brain

Promising results for:

Depression

Parkinson's disease

Obsessive-compulsive disorder

Using it instead for brain enhancement: a no-brainer?

2011: found to make mice smarter

So why not rats?

So why not humans in the rat race of life?

TMS

transcranial magnetic stimulation

No need for pesky wires in the skull!

An approved treatment for depression

Can lead to hypomania

Is that a problem?

People with hypomania are energetic and elated, which can be a kind of cognitive enhancement.

Ultrasound

Another method uses ultrasound, or sound waves above the audible range of frequencies.

Visual hemispheric invocation (VHI)

To invoke the right hemisphere, simply focus your eyes on a point, while focusing your attention on something to the right of that point in the peripheral visual field. 

           

A better method?

A tried-and-true method for cognitive enhancement is to associate with others with whom you have similar goals and interests. Sometimes called the “critical mass” effect, anyone who has been in such a group can vouch for its effectiveness.²³