Archive for the ‘Physics’ Category

How Much Oxygen Can You Pull Out of Martian Perchlorates?

June 2, 2019

(or, how my grandaddy fast-terraformed Mars in 2055)

So, maybe you’ve heard. Martian soil is about 0.5-1.0% perchlorates, that is, ClO4ions, which are supposed to be really bad for human thyroids. Being that it’s an ion, you usually find it paired up with something like sodium or potassium, so really, it’s a salt, but it’ll still kill you.

There are articles online about soil remediation using a variety of methods, because perchlorates are a problem here on Earth, too, residue from such things as fireworks and rocket propellant, and sometimes when the EPA isn’t run by idiots, we try to fix that problem. So there are ways to deal with it, including bioremediation using bacteria.

The question I pose here is; if you have the tools for bioremediation on Mars, how much oxygen could you produce in that process, and would it be a greater volume than the CO2 that’s already there? Could you fast-terraform Mars with the available oxygen?

Let’s figure it out. If you want to skip the “figuring out” part, just skip to THE BOTTOM.

I make a few assumptions that may or may not be reasonable, but let’s start with the idea that we can convert all the ClO4ions into a Cl– atom and two O2 molecules. If you wonder how we’re going to discard the Chlorine atoms, don’t forget that we started with a salt, like NaClO4, or KClO4, and can recombine with the positive ion to make NaCl or KCl, both of which are relatively harmless to humans.

Second assumption is that the 0.5% (by weight) soil contamination only goes down one meter on Mars. Martian soil, as everyone knows, weighs about 1520 kg/m(okay, I looked it up. I’m sure this varies a lot, but it’s the number I used). If 0.5% of that is perchlorate salt, that’s 7.6 kg per cubic meter of Martian surface (or square meter by area, since I speculated on a 1 meter depth).

Mars is 144.8 x 1012 square meters in area, so we get a total of 1.1 x 1015 kg of perchlorate salt. Of that mass, roughly half is oxygen. You can look up molecular weights if you like. I’ll wait.

So, roughly 5.5 x 1014 kg of oxygen! Woo-hoo! That’s a lot of oxygen. Let’s compare that to the CO2that’s on the surface (Googling it now…) Ah, dang, the COis 2.5 x1016 kg. Even at .01 atm, it outweighs the available oxygen from perchlorate remediation by 50 times.

THE BOTTOM; The existing COon Mars is about 50 times heavier than the Oyou could get out of the perchlorates in the soil, assuming my assumptions, which are many. Don’t get me wrong, 5.5 x 1014 kg of oxygen is still a hell of a lot of oxygen and you get to clean up the soil so it doesn’t kill you as you track it into your hab.

But if it isn’t enough to bulk up the atmosphere, is it worth the bother? Well, sure. I’ve been working on an SF story where humans start covering Mars (and the Moon) with tents, tall poles with clear plastic sheets on top, basically, so they’re creating an atmosphere that’s only 3 meters high. It’s well designed science-fiction plastic, so it keeps out gamma rays, the solar wind, and holds 0.5 atm pressure with ease. It’s the future!

If I’ve done my math right, we have 1.7E16 moles of oxygen, so if we’re shooting for room temperature at 0.5 atm, and using PV=nRT, we should have about 7.6E14 cubic meters of gas.  Based on the known square meters of Mars, this should give us a potential tent height of 5 meters over the whole damn surface, full of oxygen at ½ Earth pressure, assuming we can heat it to room temperature (thank goodness for all those orbiting reflectors).

Wow! Plenty of space for those 2-meter tall Earthlings to evolve into 4-meter tall Martians in the low gravity. Maybe even enough for a few giant dome-cities if you add in some nitrogen and water vapor and some carbon dioxide for the plants.

Feel free to check my math, I only ran through it once. Sometimes I make mistakes. But to all the nay-sayers telling us we can’t Terraform Mars, I say; it’s just engineering. You just need to make the top of the atmosphere much lower.

If you enjoy hard SF, consider subscribing to Analog SF, where many of my stories appear, and check out http://www.silcom.com/~tomjolly/tomjolly2.htm to find more of my stories in other places.

Running a Stirling Engine Using the Night Sky

November 28, 2018

I’m a failed inventor. I get strange ideas, try them out, and usually discover that I either got my physics wrong or built my prototype poorly, or that someone beat me to the punch thirty or three hundred years ago. I created what I thought was a great factoring algorithm for huge numbers and found out that Fermat developed it first. That’s the way it goes.

So here’s the latest invention. It’s not really an invention so much as an interesting application of an existing device.

Is it possible to make a heat engine that runs off the thermal differential between the night sky and the heat radiating from the ground? Stirling engines can run using fairly small temperature differences, such as the ambient air and the heat in the palm of your hand. You can get one of these hand-driven Stirling heat engines from ebay for under $50.  The real question isn’t so much whether you can make a device that runs off the heat sink of the night sky, but how much of a thermal delta you could provide to that engine.

How cold is the night sky? I’ve read that on a clear night, it can provide a radiative heat sink of -70˚C. Yeah, that’s negative 70 degrees centigrade. Pretty cold. Those with a background in heat transfer physics know that the other two forms of thermal transfer are conductive and convective, and with the right glass or plastic covered chamber, you can minimize those thermal paths so that your heat source/sink sees only the -70˚C of the night sky. This is why some telescopes have a problem with their optics freezing up. Really. It also explains why some windshields frost up even though it doesn’t reach freezing temperatures outside, and other related phenomena.

The other side of your Stirling heat engine could be getting its energy from the radiation from the ground, say, about 15˚C. Or if you heated up a tank of water during the day, maybe 40 or 50˚C. You could run your engine easily with a delta of 100 degrees, though as you thermal guys know, the engine would be a lot more efficient at higher temperatures during the day shift.

But, the hypothetical question is if you could run an engine off the night sky. My speculative answer is “yes”. What’s nifty about the ability to do this? Well, instead of dumping HEAT into the atmosphere to generate energy, which every power source on Earth currently does, you are actually dumping COLD (a.k.a, removing heat) into the atmosphere to run your engine. The net heat loss of your engine is NEGATIVE.

So yeah, we could cool down the Earth and generate energy at the same time. Crazy, huh? The biggest problem with the idea is that you could generate a lot more energy a lot more efficiently using a hot solar Stirling engine during the day at the same cost, while dumping more heat into the atmosphere.

And cost seems to drive everything except our self-preservation instinct.

Does the Sun have a Positive Charge?

September 23, 2018

While I was reading about Venus’ atmosphere, and how the tremendous heat had split apart the hydrogen from water molecules and sent them off into space at escape velocity, I started thinking about the Sun’s plasma.

Hot gases are interesting, in relationship to how fast each molecule is moving. Small, light molecules move very quickly, while heavier molecules slog along at a slower pace in the same gas. So, in the formula  KEAVG=½ mv2=3/2*k*T, where k is Boltzmann’s constant and KEAVG is the average molecular kinetic energy, you can see right away that for a given temperature, the smaller the mass of the particle, the higher the velocity. So, if a particle in a gas is 100 times larger than another particle, you’d expect the smaller particle to be moving √100 = 10 times as fast.

So, back to the Sun. The Sun has a plasma atmosphere, that is, it’s mostly dissociated electrons and protons and other stripped atomic nuclei. Electrons are about 1/2000 the mass of a proton, so we expect that their average velocity in the atmosphere of the Sun is going to be √2000 faster that the average proton, or roughly 45 times as fast.

What this suggests to me is that, in the solar wind, most of the particles that actually reach escape velocity from the Sun (all suns) are going to be the electrons by a large margin. This also tells me that most of the particles that reach escape velocity from our galaxy are also going to be electrons.

So, some general figures to keep in mind; the escape velocity from our general region of the galaxy is about 537 km/s. Our Sun happens to be moving about 220 km/s around the perimeter, so particles would only have to be leaving our Sun’s heliosphere at about 317 km/s to escape the galaxy. The escape velocity from the Sun’s surface is around 618 km/s, and the solar wind (protons and electrons) supposedly passes by the Earth at about 400 km/s, though as we may discover, this isn’t exactly true. The escape velocity from the Solar System, if you start from Earth orbit, is only 42 km/s, much lower than the 400 km/s stream of particles flying by our planet.

I’m speculating that the solar wind consists of very fast electrons and much slower protons; if they were moving at the same speed, they would recombine into hydrogen. And since the electrons are moving much, much faster than the protons, I’m also speculating that a lot more electrons escape from the Sun than protons.

Over a long period of time, the Sun should become positively charged as more electrons than protons escape into interstellar space and intergalactic space.

One might look at the velocities, and think, well, hey, if the protons are moving at 400 km/s, they’re all going to escape the Sun’s gravity, too, and the balance of charge will be maintained! But they aren’t all traveling at this high speed; there’s something called the Boltzmann velocity distribution curve for particles in a gas, and some fraction of those protons aren’t going to make the necessary 42 km/s as they pass by Earth; they’re going to fall back into the sun. The electrons, as we noted, are probably moving 42 times as fast, on average, as the protons, so a much smaller number of them are going to be trapped by the Sun’s gravity. Likewise, a lot more electrons will escape our galaxy than protons.

Wow, the number 42 sure does pop up a lot. I wonder if that means anything?

Anyway, we speculate that a lot more electrons will escape from the Sun than protons. This would have some interesting side-effects.

The Sun, being positively charged, is going to be pushing and accelerating protons in the solar wind. The surplus interstellar electrons will be pulling on these same protons. Likewise, the motion of the electrons in the solar wind will be retarded due to the positive charge of the Sun. Eventually, I would expect some sort of balance, while still maintaining a net positive charge on the Sun. Somewhere out there in the heliosphere, the proton and electron velocities would finally match up, allowing them to merge into hydrogen.

I read recently that there is a yet-unexplained acceleration of the solar wind away from the Sun. Perhaps this charge imbalance is related to that.

So, we have a cloud of surplus electrons in between the galaxies. We have another cloud, probably denser, of interstellar electrons within our galaxy, between the suns. And we have positively charges suns stuck in this rotating cloud like a plum pudding. Over billions of years, I’d expect the intergalactic cloud to get denser, pushing the galaxies apart as one high-velocity electron wind smashed into others, and the field pushed the galaxies apart. Could this be interpreted as the acceleration of the separation of galaxies in the universe that we see and attribute to dark energy? I have no idea. Could the plum-pudding of positive charges (stars) imbedded in a rotating negatively-charged galactic cloud appear to be more massive than it really is, as it rotates within the universe’s own electron field? I also have no idea. I’m not an astrophysicist, or a plasma physicist, or any of the other useful fields that could actually answer these questions.

ADDENDA: I tried to look up velocity distributions for electrons and protons in a solar wind. The new Parker Probe, just launched, will probably be measuring this, and the GOES satellite and ACE measured this. Looking at the ACE SWEPAM experiment live data, it looks like electrons and protons have, on average, roughly the same electron-volt values, which, as I suggested earlier, would mean that electrons are moving a lot faster than the protons, which would give us results as described. But I don’t know how good the data is, or if I interpreted it correctly.

If you like this speculation, be sure to check out my SF short stories listed at my website.

Black Hole Evaporation versus CMBR

May 5, 2018

Black holes evaporate. At least, that’s what most physicists tell us.

What I stumbled into recently was a conjecture that they can’t evaporate beyond a certain point if the input is greater or equal to their output. This was mentioned on Quora by some physicist as a response to a related question. I thought it was interesting enough to mention it here.

Really large black holes are colder than the cosmic microwave background radiation (CMBR), which is about 2.73 degrees. The radiation going into a black hole is actually greater than the radiation leaving the black hole. The only way a black hole could radiate is if it’s very small and already radiating hotter than the CMBR (plus whatever particles fall into it, adding to its mass).

The limit where the size/mass of the black hole is equal to CMBR input is about 1% Earth mass, about 4×10^22 kilograms, based on Susskind’s formula and Hawking’s formula. This would create a black hole smaller than a millimeter. But black holes can’t even form without at least three or more Solar masses to begin with.

So, any black hole larger than a millimeter is going to keep growing. Presumably, primordial black holes smaller than 10^11 kg, created during the Big Bang, would have evaporated by now. This leaves a range of possible primordial black holes from 10^11 to 10^22 kg as possible existing evaporators, since they would be hotter than the background radiation.


Primordial black holes would form because of high density and radiation. It would be crazy to think that their mass wouldn’t quickly grow far beyond Earth mass when surrounded by a buffet of dense gas and radiation. Just the nature of the formative process suggests that they will never radiate faster than mass/energy is added to them from their environment, and will always grow larger in size.

I really WANT them to exist, however. My next SF story kind of depends on it.

The Spacetime Diet: Redistributing the Fat of the Universe

October 29, 2017










Black Holes and Those Pesky Event Horizons

October 8, 2017









A Fool’s Physics

September 18, 2017



Causality Paradox? What causality paradox?

September 11, 2017

I can’t call this real physics, this is just pure and wild speculation. I had a funny idea today about whether or not you can go back in time and shoot your grandfather, thus keeping yourself from ever being born. Ethical questions aside, I thought of a possible solution to the whole “paradox” issue.

First, if you aren’t familiar with the Grandfather Paradox, you can read up on the subject at Wikipedia at https://en.wikipedia.org/wiki/Grandfather_paradox.

Start with the idea that we are always travelling at the speed of light. You, the Sun, the Earth, your brother Bob, everything is travelling at the speed of light through the time dimension, all going the same direction so your relative speed is zero. This is a pretty common concept in modern physics, so I’m not going to expand on that here. Just more physics weirdness.

So, let’s say I get the dubious urge to go murder my grandfather at some time in the past, before I was born. Using some fantastic time machine, I go back in time to when Grandpa was just a young fella and shoot him. What happens then?

Well, imagine that space and time are a 4-dimensional matrix, but that changes made in the matrix can only propagate forward at the speed of light. Remember, that’s how fast we move through time. Eventually, the change (where I no longer exist) reaches the point where I would have gone back in time, but the particles that would have made up my body go shooting forward past that point and never go back. Well, they aren’t “shooting forward” so much as redirecting the world line of their old path at the speed of light. Now, instead of making a U-turn and heading toward their fate with my grandfather, the bullet-magnet, they continue forward in time. The old worldline going backwards collapses/disappears at the speed of light and eventually catches up to where Granddad is, and lets him live. I’m born again! And I foolishly decide, again, to go back in time and kill my granddad.

What does this result in? An oscillation. The world line shifts back and forth between the two realities, carrying the data from both possible realities, like a sine wave on a current. Just as a single electrical sine-wave can contain positive and negative values as it propagates through a wire, so can events toggle on a worldline as that worldline propagates through time. Even past the point where I made my fateful decision, the world line is toggling back and forth; both realities are true, taking their turn as the decision I made causes both of them to be real. The duration of this toggling or oscillation would be twice the duration of the time from when I went back in time to when I snuffed Gramps; the duration of the whole loop.

It’s my belief (not necessarily shared by many others) that we live in a four-dimensional space time that exists perpetually as a 4D matrix, and that what we perceive as our consciousness exists at each point along that worldline. There is the version of you that you perceive now, and the version that existed when you kissed your wife for the first time, savoring the moment you’ve forgotten. Kind of a repetitive immortality.

But what I’m suggesting above is that multiple realities can exist on a single worldline; you don’t need multiple universes dividing every time a critical decision is made or a quantum observation collapses a wave function, or a bit of antimatter goes back in time and changes an existing chemical configuration. Both events occur and exist on a changing, fluctuating, dynamic 4D worldline. There’s the version of you that remembers killing your Grandfather, and the version that never existed, propagating through time, one behind the other forever on the oscillating world line.

The normal view of a 4D worldline is of a static deterministic universe, bound by the future and past configuration of an unchanging worldline. Another view is that every decision, human or quantum, splits the universe into a multiverse, a crowded infinity of infinities. This version allows us to stick with one universe, but to modulate our worldline to allow multiple realities to exist along a single timeline.

Possibly, an outside observer could interface with either version of your reality, based on where he encounters your worldline from his own worldline. Could that be the “collapse of the wavefunction” we talk about? Good grief, that would make the Schroedinger’s Cat conundrum actually possible. Dead and alive! I always thought of it as complete nonsense.

One issue with this model is that each worldline, as it moves from one reality to another, may have to move instantaneously from the collapsed worldline to the new worldline. I think. No real way to test it, that I can imagine. Mmm…maybe pick a subatomic decay process that can have multiple durations, then have someone record the decay time data, then take off (with that data) somewhere at high-speed so your worldline is no longer in sync with the experiment’s original timeline, fast enough that the time separation is greater than the decay time variance. Then, come back and see if the recorded time is the same as it was before; you’ll have two sets of readings of the duration of a single decay, and they might not agree. Wouldn’t that be something?


Background Gravity – Time Dilation in a Flat Field

August 11, 2017




So, here is my side of it.











Particle Pair Production in Deep Space

August 6, 2017



