The goal of this blog is to create a long list of facts that are important, not trivia, and that are known to be true yet are either disputed by large segments of the public or highly surprising or misunderstood by many.
Superfact 6 : Radon Represents our Largest Exposure to Ionizing Radiation
Radon represents our largest exposure to ionizing radiation.It is responsible for the majority of public exposure to harmful radiation. It is not the sun, the sky, nuclear weapons or nuclear power, or medical treatment, other terrestrial sources, it’s radon. Since we don’t talk much about the very deadly radiation emitted by the radon in our basements that may come as a surprise.
If a radioactive isotope has a long half-life, is that bad? I mean it will be around for a long time. Well, it is complicated. It is important to understand that if the decay rate for an isotope is very slow, in other words, it has a long half-life then it will be less radioactive. If the half-life is 1,000,000 shorter for an isotope X compared to an isotope Y (with a slower decay rate) than it is 1,000,000 more radioactive than isotope Y assuming their decay is of the same type. Short half life means more radioactivity. Long half-life means less radioactivity. The negative aspect of an isotope with a long half-life is that it will be around long, but the positive aspect is that it is less radioactive.
Radioactive decay is the emission of energy in the form of ionizing radiation. There are different types of decay and the decay-rate for different isotopes vary a lot. Stock Vector ID: 2417370135 by grayjay.
I should explain that isotopes mean that an atom can have a different number of neutrons. For example, carbon (coal) has a few common isotopes. C-12 has 6 protons and 6 neutrons, C-13 has 6 protons and 7 neutrons, C-14 has 6 protons and 8 neutrons. The isotope we are talking about when we talk about Radon is Radon-222. That is a really bad one. Radon-222 has a half life of 3.8 days which is 432 billion times shorter than Uranium-238, which has a half life of 4.5 billion years. So, if Radon-222 and Uranium-238 had the same type of decay (they don’t) Radon-222 would be 432 billion times more radioactive than Uranium-238.
Admittedly Uranium-238 isn’t very radioactive, you can safely hold it, but let’s take Plutonium-238, a famously radioactive isotope with a half-life of 87.7 years. Radon-222 has a half-life that is 8,424 times shorter yielding a decay rate and radiation intensity 8,424 times larger than Plutonium-238.
Radon
Radon-222 isotope has 86 electrons, 86 protons and 136 neutrons. Stock Vector ID: 1919418095 by saran insawat
So, Radon-222 is indeed extremely radioactive. But that means it should disappear quickly. Unfortunately, the inside of the earth is constantly supplying more Radon-222 from the radioactive decay and fission occurring there. Nuclear fission (nuclear reactions) is happening inside the earth providing about half of earth’s heat and powering the movement of Earth’s continents and crust. Since Radon-222 is extremely radioactive and is being resupplied by our own planet it is a very big source of the radiation we are exposed to.
Among all the different kinds of sources it is the biggest one. Since Radon-222 is a natural phenomenon, and we focus on so many other types of other natural and unnatural radiation sources we tend to underestimate the problem. At least I did when we bought our first house. I was asking Radon, what Radon? I think it is a surprising and important fact and therefore a super fact.
Radon Exposure
Illustration of how radon-222 enters a house. Stock Vector ID: 2128365599 by VectorMine.
The WHO estimates that radon exposure alone was estimated to have caused 84,000 deaths by lung cancer in one year. In 50 years, this would be 4.2 million deaths. The WHO predicted that the eventual total death toll from cancer related deaths from the worst nuclear disaster in history, Chernobyl, was 9,000, which is a lot less than 4.2 million. The numbers given by Greenpeace (which WHO does not accept) are up to a million and the Union of Concerned Scientists estimated 27,000.
Those numbers are all still smaller than the estimated deaths from Radon. Keep in mind that the Chernobyl reactor was a very dangerous reactor (RBMK) that lacked a containment shield, a reactor that could never be built in a western country. I can add that according to WHO the predicted future cancer deaths due to accumulated radiation exposures in the population living near Fukushima was between zero and a 100.
According to the United Nations Scientific Committee on the Effects of Atomic Radiation, more than 40% of the average annual human exposure to ionizing radiation is radon in the air. The other sources (all smaller) are cosmic background radiation, terrestrial radiation from the ground, radiation in food and water, exposure to radiation by medical treatment/exams, nuclear testing, Chernobyl, etc. According to former U.S. Surgeon General Richard H. Carmona, Radon is responsible for the majority of public exposure to ionizing radiation. Radon in our basements is indeed a very big deal compared to other radiation sources.
Superfact 4 : The Speed of Light In Vacuum Is a Universal Constant
The speed of light in vacuum isa universal constant. The speed of light in vacuum is the same for all observers regardless of their speed and the direction in which they are going. It is always c = 299,792,458 meters per second. If you try to catch up to a light beam and try to travel close to the speed of the light beam, you will not be able to catch up. The speed of the light beam will still be c = 299,792,458 meters per second compared to you no matter how fast you go. This is possible because time and space don’t behave like we expect.
Superfacts
This is the fifth post of my super-factful blog and my fourth super-fact. As I mentioned previously, the goal of this blog is to create a long list of facts that are important and known to be true and yet are either disputed by large segments of the public or highly surprising or misunderstood by many.
These facts are not trivia, they are accepted as true by the experts in the relevant fields, the evidence that the fact is true is impressive, and they are important to the way we view the world and to what we believe, and despite being known to be true they are hard pills to swallow for many. They are not scientific theories or complicated insights but facts that can be stated simply. In a paragraph or less. They may need more explanation than you can fit in one paragraph, but they can be stated, with a brief explanation in just one paragraph.
The Fourth Superfact
My fourth super-fact is that the speed of light in vacuum compared to yourself is the same regardless of your motion. A beam from a flashlight you are pointing forward is traveling at a specific speed c = 299,792,458 meters per second forward, no matter what you are comparing to. It is important to understand that speed is relative. If you drive 95 miles per hour on a Texas highway you are driving 95 miles per hour compared to the pavement, but you are traveling more than 2,000 miles per hour compared to the moon.
However, a light beam will be traveling at the speed of c = 299,792,458 meters per second (186,000 miles per second) compared to the pavement and also compared to the moon, the sun, the galaxy, the fastest spaceship possible and another light beam. The speed of light in vacuum is not relative. For light in vacuum there is only one speed compared to everything.
Someone passing you at the speed of 99.99% of the speed of light in vacuum will measure his flashlight beam to have the speed c = 299,792,458 meters per second and he will measure your flashlight beam to have the speed c = 299,792,458 meters per second and so will you. It is as if c + c = c. 1 + 1 = 1 not 2, didn’t you know? This is logically possible because time and space is different for different observers.
This is quite shocking if you haven’t come across it before and there are a lot of people (not professional physicists) who refuse to believe it. So, in my opinion it is a super fact. In summary:
No matter how fast you travel, or in what direction, or where you are, you will measure the speed of light in vacuum compared to yourself to be c = 299,792,458 meters per second or approximately 186,000 miles per second or 671 million miles per hour. That goes for all light beams passing by you regardless of origin.
In this picture Amy is traveling past Alan in a rocket. Both have a laser. Both measure the speed of both laser beams to be c = 299,792,458 meters per second.
In the picture above let’s say Amy is flying past Alan at half the speed of light. If you believe Alan when he says that both laser beams are traveling at the speed of c = 186,000 miles per second, then you would expect Amy to measure her laser beam to travel at a speed that is half of that c/2 = 93,000 miles per hour, but she doesn’t. She measures her laser light beam to travel at the speed of c = 186,000 miles per second just like Alan. This seems contradictory.
The solution that the special theory of relativity offers for this paradox is that time and space are relative and Amy and Alan measure time and space differently (more on that in another post).
Time is going to be different for me than for you. From shutterstock Illustration ID: 1055076638 by andrey_l
I should add that the realization that the speed of light in vacuum is a constant regardless of the speed or direction of the observer or the light source was a result of many experiments, which began with the Michelson-Morley experiments at Case Western Reserve University, Cleveland, Ohio in the years 1881-1887.
At first scientists thought that there was an ether, which acted as a medium for light. They assumed that earth would be moving through this ether. What they tried to establish was earth’s velocity through the ether, but all measurements resulted in light always having the same speed, in all directions, all the time, in summer and in winter, no matter in which direction earth was going. At first, they tried to explain this by saying that the ether compressed the experimental equipment and distorted clocks exactly so that it seemed like the speed of light in vacuum always came out the same.
Others said that earth was dragging the ether with it, but that explanation turned out not to hold water. With the special theory of relativity in 1905 those speculations were laid to rest. It was the way time and space were constructed and connected.
The first Michelson-Interferometer from 1881. It was used to measure the speed difference of two light beams (well a split light beam) with a very high accuracy (for the time). The light traveled with the same speed in all directions and no matter what earth’s position and speed was in its orbit around the sun. This picture is taken from Wikipedia and is in the public domain of the United States.
The speed c = 299,792,458 meters per second is a universal speed limit created by time and space
I should point out that there is nothing magical about the speed of light in a vacuum. Light traveling through matter, like glass or water, does not travel at this speed c, but slower. That is why I keep saying the “speed of light in vacuum” instead of “the speed of light”.
It is also not entirely correct to say that the speed of light in vacuum is a universal constant, because it isn’t only about the speed light. It is just that light that travels unimpeded through vacuum reaches the universal speed limit created by time and space, or the space-time continuum (that’s another post). The light is prevented from traveling infinitely fast by this speed limit, and light is not the only thing behaving this way. All massless particles / radiation is prevented from reaching infinite speed by this universal speed limit and they will also travel with exactly the same speed c = 299,792,458 meters per second compared to all observers, just like light in vacuum.
So how is time and space arranged to cause this universal speed limit? Well, that is a surprising super fact post for another day (I will link to it once I have made the post). I can add that the discovery that light in vacuum is a universal constant changed basically everything in physics. We had to change the equations and the physics regarding not just time and space but energy, momentum, mass, force, electromagnetics, space geometry, particle physics, and much more. The energy and mass equivalency is a direct result of this E = mc2.
Examples:
Below are some examples of what this discovery led to. Again, don’t worry about the details or how it works. I might explain these effects in future super fact posts and link to them.
Time for travelers moving fast compared to you is running slower.
Length intervals for travelers moving fast compared to you are contracted.
Simultaneous events may not be simultaneous for another observer.
The order of events may be reversed for different observers.
If you accelerate to a speed that is 99.999% of the speed of light you still haven’t gotten any closer to the speed of light from your perspective. Light in vacuum will still speed off from you at c = 186,000 miles per second. You think you’ll keep accelerating but that the light keeps accelerating just as much ahead of you. You cannot catch up. What other observers see is you accelerating less and less and never catch up even though you get closer.
Forces, the mass of objects, momentum, energy and many other physical quantities will reach infinity as you approach the speed of light in vacuum assuming you are not a massless particle.
Mass is energy and vice versa E = mc2
Magnetic fields pop out as a relativistic side-effect of moving charges.
Mass is energy and vice versa, a direct result of the way time and space are related. Stock Photo ID: 2163111377 by Aree_S
Can We Travel Faster Than The Speed Of Light?
So, it seems like we cannot travel faster than the speed of light in vacuum. It seems like the universal speed limit is a hard limit, unlike the speed limits on Texas highways. That is maybe true, at least locally where we are.
However, you could get around it, by what is kind of cheating, by stretching and bending space to the extreme by using, for example, enormous amounts of negative energy. That’s happening to our Universe over a scale of tens of billions of lightyears. I should add that a lightyear is the distance light in vacuum travel in one year. Stretching and bending space is not part of the special theory of relativity. That is Einstein’s General Theory of Relativity.
Superfact 3 : Economic Externalities Are Spoilers of Free Markets
Economic externalities are spoilers of free markets. So called externalities result in unfettered free markets being non-optimal and can render the correct government intervention more effective even from a purely economic perspective. This comes as a big surprise to the market fundamentalists who believe that an unfettered free market is always the best approach for the economy.
An economic externality or external cost is an indirect cost or benefit to an uninvolved third party that arises as an effect of economic activities. They are unpriced components of market transactions.
An example is the gasoline you buy. Burning the gasoline causes pollution that harms other people including those who do not own cars, future generations, and it harms the environment including animals. Society incurs a cost from that pollution that you don’t pay for at the pump. The gasoline producers and vendors do not pay for it either. Unless you add a tax or make other adjustments the act of polluting is free of charge, even though there is a real cost associated with it. It is a cost that is invisible to unfettered “free markets”. It is a market failure.
Note I am putting “free markets” in quotes because the free market does not exist all by itself. It exists within a framework of laws, a banking system, and entities such as limited liability corporations, etc.
Pollution is an example of a negative externality. Photo by Chris LeBoutillier on Pexels.com
Economic Externalities
The existence of economic externalities is entirely uncontroversial among economists, including laissez-faire (libertarian) economists such as Milton Friedman, Friedrich Hayek, and Ludwig von Mises, even though Ludwig von Mises said that they arise from lack of “clear personal property definition.” In fact, Milton Friedman, Nobel prize winner in economics, and a leading anti-tax champion, stated that pollution met the test for when government should act, but that when it did so, it should use market principles to the greatest extent possible — as with a pollution tax. The unfettered free market is not optimal.
This simplified supply and demand graph shows two different graphs in blue. One for the private/production cost per unit of a goods and a second that also includes the cost of the externality.
However, in my experience the existence of economic externalities is unwelcome news to less educated market fundamentalists, including many libertarian leaning politicians. I don’t have a Gallup poll to back this up, but I believe it is correct to say that economic externalities are controversial among a significant portion of the public despite being a universally accepted and a fundamental concept of economic science. Externalities are known to exist and that is not an easy pill to swallow for some.
The existence of externalities is sometimes a hard pill to swallow. Photo by Artem Podrez on Pexels.comThis simplified supply and demand graph also shows two different graphs in blue. Again, one for the private/production cost per unit of a goods and a second that also includes the cost of the externality. In this case the cost for production goes down as quantity increases but the cost of the externality goes up per unit perhaps because increasingly damaging production methods are used as the quantity increases.
In the simple supply-demand graphs above we see how the price of a product per unit (private cost / or production cost) varies with the increased quantities produced. In the first graph, as the production quantity increases the production cost per unit goes up perhaps because labor and other resources get increasingly rare. In the second graph, as the production quantity increases the production cost per unit goes down perhaps because production becomes more efficient with increased quantities.
In both cases demand goes down with quantity (the red demand curve/line) because fewer people want to buy more of the product as the quantity increases. In both cases the externality adds a cost. In this case the externality cost per unit goes up because increasingly damaging production methods are used as the quantity increases. There are many possible examples of these graphs, but the point is that the externality adds a cost that reduces quantity sold in a free market, assuming the cost of the externality is accounted for.
Economic Externalities In The Real Word
Unfortunately, in the real world, externalities are often not accounted for, and figuring out the real cost of an externality is a thorny issue. However, if we know the cost of the externality and have a way of accounting for it, perhaps via tax or a fee, then we would reach a new equilibrium, a new optimal price for the product that will include the social cost. I can add that in the 1920’s an economist Arthur Pigou argued that a tax, equal to the marginal damage or marginal external cost on negative externalities could be used to reduce their incidence to an efficient level.
Notice this tax is not for redistributing wealth or bringing revenue for the government but to reduce economic harm to society. There are other ways to address the problem, but this type of tax is called a Pigouvian tax.
How a Pigouvian tax can reduce economic harm to society. Photo by Pixabay on Pexels.com
Finally, I would like to give a few examples of negative and positive externalities. Negative externalities could be :
Pollution
Climate Change
Depletion of fish due to overfishing
Depletion of other resources
Overuse of antibiotics
Spam email
Some positive externalities are :
A beekeeper keeps the bees for their honey, but a side effect or externality is the pollination of surrounding crops by the bees.
Education (societal benefits beyond the individual).
Research and development.
Innovations
Scientific discoveries
Vaccination
When a beekeeper keeps bees for their honey, a side effect is the pollination of surrounding crops by the bees. This is an example of a positive externality. Photo by Pixabay on Pexels.com
Some things cannot be known. There are things in mathematics and about our physical world that we know can never be known. For example, we can’t simultaneously know both the exact speed and the exact position of small particles (Heisenberg uncertainty principle). This is not because of a limitation of our instruments. It is a fundamental property of the Universe. But there are more examples of unattainable knowledge. In mathematics there are true statements that can never be proven.
“This”Some Things Cannot be Known” is the third post on my super-factful blog. As mentioned, the goal of this blog is to create a long list of facts that are important and known to be true, yet either disputed by large segments of the public or highly surprising or misunderstood by many. They are facts that are so unnecessarily controversial or astounding that I refer to them as super-facts.
This post is about a fact that may be highly surprising to many. Science knows a lot. People without a solid education in science are often surprised when they find out about some of the amazing things we actually do know.
For example, just by studying the light from a distant star, we can determine what elements it is composed of. The star may be composed of 71% hydrogen, 27% helium, 1% Lithium, and 1% other elements, and we can know that just from its light. We can also determine its temperature, the distance to the star, how it is moving compared to us, where it will be 2.5 million years from now, roughly its age and longevity, and more. 150 years ago, we could not have dreamed of this capability.
We can know so much about a star from its light. Shutter Stock Illustration ID: 566774353 by Nostalgia for Infinity.
However, there are also many things we don’t know, and what may come as a big surprise, we know that there are things we can never know, no matter how advanced science becomes. Infinite experimentation, super intelligence, a quintillion super geniuses, infinite time, we simply cannot acquire some knowledge. The universe itself forbids some knowledge. It also means that the statement “nothing is impossible” is false.
At least my natural reaction to such a claim is, “come on you can’t say that with certainty”, and I expect many others will feel the same. However, the reason some knowledge will never be attainable is that physical laws as well as mathematics and logic forbid some knowledge. Some things are not meant to be known. I will give four examples in the four sections below: the event horizon, the Heisenberg uncertainty principle, beyond the observable Universe, and Gödels incompleteness theorem.
The Event Horizon of a Black Hole
A black hole is a region of spacetime where gravity is so strong that nothing, including light, can escape it. The boundary of no escape is called the event horizon. If you pass the event horizon you cannot come back out no matter how much energy, you expand. Nothing can escape, no matter, no radiation, not light or other electromagnetic radiation, and no information. Nothing at all can escape. The curvature of time and space itself forbids it.
I should add that right at the event horizon, there is so called Hawking radiation, but without complicating things it is not the same thing as escaping a black hole. You can guess from physical laws what might be inside, but you can never observe and report what is inside to planet Earth.
Black Hole Stock Photo ID: 2024419973 by Elena11
I would also like to add some basic information about black holes. Some black holes are formed when large stars die and collapse. These black holes are estimated to have a mass of five to several tens of solar masses. However, there are also super massive black holes that reside in the center of galaxies.
The super massive black hole at the center of our galaxy, the Milky Way, is called Sagittarius A* and is estimated to have a mass of four million times the mass of our sun. The largest known supermassive black hole TON 618 is 66 billion times more massive than our sun. There are an estimated 100 million black holes in our own galaxy, the Milky Way. One interesting fact is that celestial objects can orbit a black hole, just like planets orbit the sun, but as you get too close you will rush, at the speed of light, into the depths of the black hole.
The Heisenberg uncertainty principle
The Heisenberg uncertainty principle states that it’s not possible to know the position and momentum of an object with perfect accuracy at the same time. Another way of saying that is that we cannot know both the position and speed of a particle, such as a photon or electron, with perfect accuracy. The formula is: dX * dP >= h/4pi , or uncertainty in position (dX) times uncertainty in momentum (dP) is larger than half of Planck’s constant. There is also an energy and time precision limit : dT * dE >= h/4pi.
These equations basically means that there are no perfectly exact measurements or knowledge. Everything is a bit fuzzy. Planck’s constant is very small, so Heisenberg uncertainty principle does not matter for everyday objects, but it matters when sizes are very small (positions, energies, etc.) Note, Heisenberg uncertainty principle is not because of a limitation of our equipment, but a limit set by a law of physics. It is a limitation set by the Universe if you will.
Heisenberg uncertainty principle Shutter Stock Vector ID: 2380436193 by Sasha701
Beyond the observable Universe
The observable universe is a ball-shaped region of the universe consisting of all matter that currently can be observed from Earth or its space-based telescopes. The radius of the observable universe is 46.6 billion light-years. The size of the observable universe is growing. Unfortunately, at those distances, space itself is stretching/expanding faster than the speed of light. Since no signal or information can travel faster than the speed of light we are losing, not gaining, celestial objects from the observable universe.
In the past we’ve lost many galaxies this way. Since the expansion is accelerating, we will keep losing more galaxies beyond the boundary of the universe and some galaxies were always lost (with respect to observation). I can add that the universe may be infinite.
A view of a galaxy full of stars. Photo by Pixabay on Pexels.com
If we are wrong about the fact that the expansion of the universe is accelerating, then perhaps we can observe more galaxies in the future. But if not, then there are galaxies that we have never observed, galaxies that we can never observe, and there are galaxies that will become unobservable in the future. Depending on the size of the universe we may never be able to observe more than an infinitesimally small portion of the universe. Again, the universe is stopping us from knowing something.
Gödels incompleteness theorem(s)
The theorem states that in any reasonable mathematical system there will always be true statements that cannot be proved. In other words, to find a complete and consistent set of axioms for all mathematics is impossible. There are forever hidden truths in mathematics. For the case of natural numbers this means that there will always be statements about natural numbers that are true, but that are unprovable. I can add that there is also a second incompleteness theorem that states that a formal system cannot prove that the system itself is consistent. Basically, there are limits to mathematics set by logic. And some things cannot be known.
I have a book on Gödels incompleteness theorem, which I have not read, but I will read it before I make a post about it. Photo by Andrea Piacquadio on Pexels.com
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