Physics

The greatest source of detail on physics is available on Wikipedia, a site that does not in any way relate to me. It is free to use and needs your donations to continue. Please use Wikipedia to conduct your own research and receive from them tremendous detail. If you can, please give them a small donation. What follows is a distillation of what you might want from physics to help you write better sci-fi.

Quite possibly, the greatest philosophy ever devised, is the scientific method. The oldest recorded practiser and possibly codifier of the scientific method was Ibn al-Haytham Latinised to Alhazen, he was a Muslim scientist circa 965 – 1040 AD. He was also much later in time, given many honourable names, notably being called ‘The Physicist’. He was, in retrospect, part of the Islamic scientific revolution, who’s collective work when translated, passed on great advancements such as al-jebr meaning "reunion of broken parts”, to become algebra. These works in translation led to greater scientific understanding in the European ‘Renaissance’ (14th – 17th century).

Sir Isaac Newton took the scientific method further and developed descriptions on the laws of physics we now call Newtonian physics (25th Dec 1642 – 20th Mar 1726). Shortly after in Britain was the Industrial Revolution (circa 1760 – 1840) and from the USA in 1969 NASA put people on the moon. Having left almost everything out to make it this brief, the history of development can to be shown to come from the application of the scientific method.

So, in relative terms, we have a new explanation for the universe, called physics, and it explains all physical interactions, hence its name. Looking at the atom we have particle physics and nuclear physics. From understanding the electrons acting in shells around the nucleus we get to understand covalent bonds, and from that we get chemistry. Had it been known before it was studied, chemistry might have been called molecular physics, as it is a branch of physics. It's origin is actually ancient, both with the Greeks and later with the Romans inventing concrete 2000 years before everyone else but not really understanding it. Chemistry was advanced a long way again by the Muslim scholars leaving it primed to be picked up the Europeans who as with Physics, first learned it from the Muslim scholars texts. To give it a European name they took the words al-kimiya (already Latinised), meaning 'philosopher's stone', and made the word Alchemy. In studying alchemy, comparing similarities and differences, alchemists concluded that if you could find the right reaction, then you could turn lead into gold. They were half right. In refining alchemy, we get chemistry, with that the Periodic Table, which is the bridge between physics and chemistry. Chemistry is effectively just the entropic decay of electrons so it can't turn lead into gold, as the charge that defines an element is in the core, not the shell. However nuclear physics can and has turned lead into gold. Biology is half explained by chemistry and half by a macro logic effect (evolution) and so in my head it is half physics and half economics.

As physics explains the truth of matter, its understanding provides accuracy and in skirting the limits of physics, it provides us with the boundaries that make for good stories. Applying and breaking physics through our humanity makes science fiction. Magic is myth and fantasy, although fiction and fantasy are nearly the same words. I choose to define them with a subtle difference where a fiction is a probable untruth, where as a fantasy is an improbable truth. I would happily jump on a fictional hover board, but I don’t have any fantasy to suddenly grow wings and fly like an actual bird.

To me, fiction has more meaning. I know that in being presented with two bookshelves, I will look at the science fiction before the fantasy so I do like to make the distinction. Unfortunately science fiction and fantasy often share the same bookshelf, due to the lack of interest and or good writing. Robilliverse aims assist in freeing up authors. I do of course still enjoy fantasy, the Harry Potter books are phenomenal and even got me into reading, starting of course with, 'The Philosophers Stone'. Over all though, I seek to be near the physical reality so I aim to provide the basics of physics, to show you which rules I break to get back to our humanity, the Fi-sics. Each of these will have a purpose, for example FTL (faster than light) is a good way to skip the vast distances in space. We have no evolutionary history that operates on this scale of distance so it is ‘inhuman’ to traverse it at any real achievable speed. If that was one option of two options, we’d all happily choose the second one to get on the FTL travellator that could take us to a planet similar to our own as opposed to being stuck in space.

SI Units

To allow scientists to relate their findings, the Système International d’Unités (SI) was created to establish standard base units of measurement. These are:

Length (distance) – measured in Metres
Mass – measured in kilograms (not grams)
Time – measured in seconds
Electrical Current – measured in amperes (amps for short)
Temperature – measured in kelvin
Luminosity (brightness) – candela
Amount of mass per substance – measured in mole.

Length

The length of something is an incredibly key aspect to a story. Things are always a distance apart from something and it needs to be respected. To get a better handle on it, I’ve created a kilopower scale that can be applied to distance, which also deals with the constant switching between metres and kilometres.

Blue Whale 25m or 25:0
Earth’s crust thikness 40km or 40:1
Earth’s radius 6,371km or 7:2 (Planetary scale)
Earth to Moon 384,400km or 384:2
Sun to Mercury 58m km or 58:3
Sun to Earth aka 1 Astronomical Unit (AU) 149,597,871km or 150:3
Sun to Mars 228m km or 228:3
Sun to Asteroid Belt 420m km or 420:3
Sun to Jupiter 779m km or 779:3 (Scale starts ramping up beyond here)
Sun to Saturn 1.4b km or 1.4:4
Sun to Uranus 2.9b km or 2.9:4
Sun to Neptune 4.5b km or 4.5:4 (note that the entire previous solar system could fit between Uranus and Neptune)
Sun to Pluto 5.9b km or 5.9:4
Sun to Heliopause 100AU or 15:4 (we’re all still learning about this one so actual distance might be different from currently thought)
Sun to Oort Cloud 50k AU or 8:5
1 light year 9.4605284*10^15m or 9:5
1 parsec 3.08567758*10^16m or 31:5
Sun to Proxima Centauri 40:5 (nearest star)
Sun to Bernard’s Star 56:5
Sun to Tau Ceti (star) 112:5
Diameter of Milky Way (our galaxy) 946:6 or 1:7
Distance to Andromeda (nearest galaxy) 24:7

Beyond the inner planets, the scale starts shifting upwards where a trip to Mars, Neptune or Proxima Centauri all operate on different scales. For this I invented the Merlin Engine as an upgrade to rockets, the Impossibility Engine for an in system speed increase and portals as a method of travelling between stars.

Mass

Initially, it doesn’t seem that exciting but then I realise it IS the physical.

Sir Isaac Newton’s famous second law of motion telling you how much something will accelerate while you apply force to it.
F=MA
Force = Mass * Acceleration
Momentum taken from a F=MA
p=mv
Momentum = Mass * Velocity
Special Relativity. An objects mass increases as you approach the speed of light. It’s why light speed cannot be passed as nothing can push a mass faster if it gets more massive when you push it. Time also dilates so your push gets slower (as observed from another point), but enough about special relativity.
General Relativity. Mass effects the curvature of spacetime.
Also you can work out the energy of mass using Albert Einstein’s famous energy-mass equivalence formula:
E=MC²
Energy = Mass * The speed of light * The speed of light
It tells you how much energy you get out from nuclear fission and nuclear fusion.

Time

Time is a dimension measured in seconds. In physics there is spacetime and in economics (which I hold to be a branch of physics, ok I’m a little obsessed with physics) there is moneytime (which I might have just invented). Net Present Value or NPV is an expression of moneytime where the value is set to now. Money as a concept holds no meaning without time so time is always factored in, even if it’s mostly implicit and the time is now.

Special relativity means that if you are on a ship accelerating out of the solar system and traveling near the speed of light, then you will appear to slow down from an Earth observer; such is the fate of HASS Svarga

Electrical Current – measured in amperes (amps for short)

These can kill you quite happily, but its sister, volts generally won’t, except the amount of volts is related to amps. One ampere is the measure of the amount of electrical charge passing a point per unit time, with an equivalent charge one coulomb (6.24150934*10^18 charge carriers per second, which is a lot of electrons in a typical circuit).

Electricity is effectively a flow of electrons, so in order to have an amp flow from one side to the other, you need to have an electrical potential between two parts of an electrical circuit. This is voltage and there is one across a charged battery, and not one across a flat batter. As it is acting as force it relates in the following equation.
Voltage = (mass x area) / (electrical current x time cubed)
V = (kg*m²) / (A*s³)

What’s really interesting is the watt. It is a unit of power, that is to say energy per second. The best way to think of it is to lie on your back and hold a heavy book above your head. As you hold it steady, nothing is moving but you are nonetheless fighting Earth’s gravity. You are maintaining a constant power and because of this your arms eventually get tired. What makes it so interesting is the following relationships:
Speed = distance over time.
v = m/s
Acceleration = the increase in meters per second every (per) second.
a = m/s²
Force (newtons) = Mass x Acceleration
N = kg * m/s²
A joule is a unit of work.
1 Joule of energy is transferred when the force of 1 newton is applied for 1 meter.
J = Nm
Watt is a unit of power, the rate of work per second.
W = J/s
So:
W = J/s = (N*m)/s = (kg*m²) / (s³) = (kg*m*m)/(s*s*s)

From this I took the power output of a fusion tokomak, directed the energy via magnets into accelerating the waste charge electrons out the tokomak creating thrust and invented the fusion engine (at least theoretically). Mine for Robilliverse is called the Merlin Engine.

Temperature – measured in kelvin

Temperature is actually a measure of energy. When people say the world is getting warmer, they actually are saying the world is getting more energetic. So, if the world is getting more energetic, it might be expressed as wind speed rather than hotter air. Of course you need to remember the law of the conservation of energy, so any speed energy might get transferred back into heat.

When we talk about temperature, we are generally talking about the specific energy in atoms of a specific mass. I won’t dwell on this too much, as it is commonly understood. In essence, what we’re talking about is the change across the five states of matter:

Bose-Einstein Condensate (check out superviscosity)
Solid
Liquid
Gas
Plasma (electrons not orbiting the nucleus)

The official measure of temperature is kelvin (where you don’t have to say degrees first). It was created as an absolute scale with the theoretical thermodynamic zero kelvin being the point where matter doesn’t have energy. With kelvin, maths doesn’t get awkward crossing through a zero point and by its definition, you also can’t have negative kelvin. As the zero point was the important bit, Lord Kelvin (William Thomson) cleverly chose to adopt the scale devised by the Swedish astronomer Anders Celsius, also known as centigrade due to the 100 degrees between freezing and boiling.
Degrees Celsius = Kelvin -273.15
Degrees Fahrenheit = Kelvin * (9/5) -459.67

The problem with making thermometers is in their calibration. At school I learned that the freezing point of water, or zero degrees Celsius is used where the water is pure, and at 1 bar of pressure, noting that pressure is a very important factor as water can be seen to boil at around 90 C at around 3km up a mountain as the air pressure is lower. I then later learn that it takes energy to transition a phase of matter and while in the transition, the matter is said to be in both phases, i.e. a double point. Also ice water is a crystal that cannot form unless part of it randomly happens to turn into an ice seed. Pure water tends not to do this so it can be cooled below freezing. Most ice actually forms around an impurity at 0C, but that means you’re not just measuring water. So calibrating thermometers to all be the same based on the freezing point of water is actually hugely inaccurate. Water does have a fairly unique property though… it actually has a very precise triple point where only at an exact temperature, it can exist as a solid, liquid or gas, and that is how we define 0C.

Another interesting aspect to temperature, is that for things made hot, after a certain point, they will start to have their electrons jump to outer shells where they are inherently unstable. The electrons will then fall down a shell again and release the energy as a photon of light. In other words, really hot things emit light, which is how an incandescent light bulb works. It also makes volcanoes look amazing at night. The incandescent bulb however has a really interesting history you might not expect, as detailed on Wikipedia.

On a side note, chemicals in plants such as menthol in mint, fool the brain into thinking the mouth is colder than it is. Equally effective but the opposite way, chilli peppers produce capsaicin which fools the brain into thinking your skin is on fire. It’s definitely not an SI unit as the temperatures are perceived, and not real, but everyone needs to know about the Scoville scale, the measure for spicy heat in food.

Luminosity (brightness) – candela

Lightbulbs used to be sold under the measurement of Watts, as that was the amount of electrical power used to create brightness. It was logical from one perspective, as everyone used the same design and so the efficiency could be a constant. Also the human brain adapts with the eye, to the light in the room, which is what makes photography so awkward at after-dark parties. Watts as luminosity was ok initially, even though the energy to light efficiency actually wasn’t constant. Later however, the invention of the incandescent lightbulb was joined by the subsequent fluorescent, halogen and LED lightbulbs. Now we need to measure the actual light output for a comparison, so we measure the luminosity in, ironically, candle power. As it’s helpful, here is a comparison table:

Old lightbulb W = luminosity lm = effect
40W = 430lm = background lamp. Not enough to light a room
60W = 740lm = lights a corridor effectively, but not enough to sit in. A good bedside lamp brightness.
100W = 1400lm = An effectively lit room. Good for any activity.
150W = 2250lm = At night time, to the human brain, this feels like daylight. It's actually not even close.

Note that illuminance is measured in Lux and is the apparent light on a square metre.
1lx = 1lm/m². Real daylight is about 120,000 lux.

Amount of Mass per Substance – measured in mole

Mass is great to use when talking about big lumps, but when we are talking about atomic interactions, or even only chemical reactions, we need to think about numbers of atoms not the total mass. After all, helium is half the mass of hydrogen and if you look on the periodic table you’ll see that a typical oxygen atom has an atomic mass of 16*. So if you have a recipe to make H2O you want to ask for a mass ratio of 2 mol Hydrogen and 1 mol Oxygen and not 2kg Hydrogen and 32kg Oxygen. This gets especially complicated when you start to use molecules such as water, to mix with other things, so you use the mole quantities. If you want to know how many particles you have in the mass you use the Avogadro Constant.
1 gram / atomic mass = 6.0221412927*10^23 molecules
1 gram of hydrogen has 6.022*10^23 molecules
12 grams of carbon-12 has 6.022*10^23 molecules

*Oxygen has 8 protons separated by 8 neutrons. It’s the electrons held in the shells that give an atom its properties and 1 electron is held by 1 proton so it can be said that an element is defined by the number of protons in its shell. Note that carbon is defined by having 6 protons and typically is balanced out (stable) with 6 neutrons, however it is capable of holding up to 8 neutrons. Any more than 6 though is unstable and decays down to carbon 12 over a few thousand years. The sunlight constantly makes carbon 14 in the upper atmosphere and plants take on fresh quantities when they grow. The food chain starts with plants so anything alive takes in fresh carbon 14. When things die, the amount of carbon 14 begins to reduce through nuclear decay at a predictable rate. As the decay curve was cross checked with dendrochronology, tree rings, radiocarbon dating has become a very effective dating tool to anything that once lived.

Writers Notes

The purpose of all this physics is to provide you with the tools to apply real world physics to your science fiction. The restrictions to reality will fuel your stories so do not try to work them out with vagueness. Let them build a wall so you strive to go around it, cleverly dig under it, skilfully jump over it or simply smash through it!