What if explorers found life inside Jupiter, Saturn or Neptune? Or what if those gigantic exoplanets recently discovered by the Hubble Space Telescope or the James Webb Space Telescope turn out to host life?
“Impossible,” you may say.
“Not so fast,” another may say.
But not Life as We Know It
Conventional wisdom assumes life would most likely occur on an Earth-like planet. Such a planet must have temperatures similar to Earth’s and most importantly host liquid water. But would life have to be similar to Earth’s?
On a gas giant planet, such as Jupiter, there is no liquid water or soil. Sunlight would be too weak for the photosynthesis which dominates on our planet.
What did Steven Hawking and Carl Sagan, famous scientists, have to say about life existing within a gas giant? Spoiler alert: They didn’t reject the possibility.
But Why Haven’t We Detected Life on Jupiter?
Indeed, if creatures do exist in Jupiter, how would we see them inhabiting the depths of Jupiter’s atmosphere? Could we ultimately detect them in the far future, with advancements in space craft technology?
Yet, one of Sagan’s speculations involved whale like creatures inhabiting closer to the surface. Surely we might have seen them by now?
Maybe if the whales are over 1300 kilometers in diameter, we might see one if we’re lucky!
What about Carbon?
Life as we know it uses carbon as a key component. Is there a source of carbon in Jupiter?
There are traces of methane and ammonia in Jupiter’s atmosphere . Both of these molecules contain carbon.
Could Jupiter Sinker Creatures Exist?
Other than whale-like creatures, Sagan also mentioned sinkers could exist. Sinkers fall to their doom in the dense and hot lower atmosphere, but produce tiny offspring that would be pushed into the relative safety of the upper atmosphere by swirling currents.
However Sagan stated could. This doesn’t mean sinker type creatures do exist. Nevertheless, science fiction writers could employ sinker-type creatures in their stories about Jupiter. Right?
And there are other gas giants in our solar system. These are Saturn, Neptune and Uranus. Perhaps life could exist there for the similar reasons as for Jupiter?
What if We Never Find Gas-Planet Life in our Solar System?
In the future, assuming space exploration proceeds, we could explore all the planets of our solar system in depth. Only then, can we know whether life exists in any of the other solar-system planets—besides Earth.
And if we don’t find this life, this does not rule out the possibility of life in gas giants beyond our solar system. Consider planet PSR J2322−2650 b located about 750 light years from Earth. This planet has a mass of nearly 80% of Jupiter’s, but otherwise is a particularly weird planet.
Or life could exist on HD 209458 b, a planet some 157 light years away? Studies undertaken by using the Hubble Space Telescope have revealed the planet to be similar to Jupiter.
Remember these are speculations, albeit scientifically plausible. Until science finds evidence about such life being impossible, science fiction writers may employ such life in their stories.
Peter Spasov. Last updated Friday January 16, 2026
What if we haven’t yet encountered any extraterrestrials because they wear invisibility cloaks?
This question sort of answers: What is the Fermi paradox?
Once upon a time some physicists met around the table. Maybe they reminisced about developing the world’s first atomic bombs. According to some Enrico Fermi asked, “Where is everybody?”
They knew Fermi referred to extraterrestrials.
What makes this a Paradox?
We know life exists on Earth. Science explains why. Many scientists have suggested extraterrestrials could exist elsewhere in our galaxy. Why not? Estimates suggest our Milk Way has anywhere from one hundred billion to four hundred billion stars. According to NASA, our galaxy contains at least one hundred billion planets.
Recent discoveries suggest our Milky Way has at least three-hundred million Earth-like planets. If life only evolved on one out of a million of these planets, three hundred planets in the Milky Way would bear life.
Could some of this life have developed into a technological civilization? If so, then why haven’t we yet seen signs of them? This is the essence of the Fermi paradox.
But haven’t we already found Signs of Aliens?
Do some ancient structures, such as the Egyptian pyramids, prove that advanced extraterrestrials must have assisted our ancestors to build them? In brief, ancient structures don’t ‘prove’ extraterrestrial visitors were responsible. However, these speculative theories do make a good story. And writers should be free to speculate.
Maybe I’ll explore related topics in a future post, such as what is scientific proof and so on.
Has Earth already received Alien Visitors?
Aside from the preceding section, there are stories about UFOs and other suggestions such as ancient stories. I’ll repeat my mantra. Perhaps this will be a future topic.
Yet I’ll say this. A good writer could invent a good story from the possibilities.
Does Life have to be Earth-like?
We don’t know for sure. Some scientists have speculated on possibilities. For now I won’t delve further into this question. Perhaps a future post will cover the question.
If Earth-like conditions weren’t required, this would increase the likelihood of other life in the Milky Way. For instance, there could be alternate biochemistries. Again, if this life could evolve into a technological civilization, why haven’t we yet detected signs of them?
How likely is it for Life to Evolve into a Technological Civilization?
This is a good question. Perhaps I will explore this in a future post. For a hint, consider the Drake Equation. So far, the numerical values of its factors are speculative.
Other Questions
How could we detect extraterrestrial life beyond our solar system? How could we detect non-terrestrial technological civilizations? For example, spectroscopic measurements of an exoplanet may show gases which could only be produced by industrialization. Or we detect radio signals with complex patterns which repeat occasionally, as would be the case with our own radio transmissions.
If found, decoding the signals could be challenging. Extraterrestrial radio would use different broadcast standards and the extraterrestrials would use different languages. Perhaps they write by tying knots. Such a technique could be akin to Inca quipu.
There are other possibilities which could be the subject of future postings.
Answers to the Fermi Paradox
The simplest answer is: Only Earth bears life, or only Earth hosts technological civilizations. But this answer wouldn’t be any fun, would it?
Speculative fiction demands a better answer. Let’s check out alternate explanations. These include:
A. The civilizations have yet to develop a technology which people could detect from Earth. Civilizations wouldn’t all develop at the same time. What if Earth happened to be the first civilization in the Milky Way to have sufficiently advanced technologically?
B. All civilizations eventually collapse, meaning they no longer use a technology which humans could detect from Earth. Reasons for collapse could social upheaval, a massive nuclear war, environmental disaster and other reasons.
C. Extraterrestrial civilizations don’t use a technology which we could currently detect. For instance, the extraterrestrials may communicate solely by thoughts and/or travel virtually by using ghost-like proxies. They may bioengineer other life forms to produce all the material goods they need. Perhaps the civilization is solely monastic. The citizens favor intellectual activities such as developing mathematical theorems which they choreograph with elaborate dances. They have no interest in the activities many humans enjoy doing. Let your imagination soar about how other civilizations may behave.
D. Advanced cultures shirk technology entirely. The citizens have highly advanced minds which is sufficient for stimulating their psychological needs. They may consciously dream realistic worlds as a form of entertainment. Perhaps they have discovered how technology may complicate their lives unnecessarily. They have found happiness without requiring extra material goods beyond those required for survival. Physical travel doesn’t interest them.
E. Extraterrestrial civilizations mistrust outsiders. Some humans also suggest we shouldn’t be advertising our presence to potential extraterrestrials. What if any extraterrestrial society more advanced than us would inevitably eliminate or colonize us. Don’t think that could happen? Our history of genocide and colonialism has shown otherwise.
Granted, the last possibility is a downer. The opposite could be true. Here goes.
F. Extraterrestrials, being smarter than us, tend to respect all other life forms. Such a civilization might prefer to quietly study others so as to not interfere with the society. This could be a more extreme form of Star Trek’s prime directive where any contact is forbidden.
Would Extraterrestrial Civilizations Tend to Hide from Others?
This is possible. See the preceding points E and F. Extraterrestrials of either type E or F would wish to remain invisible when visiting us. For this purpose they could wear invisibility cloaks.
But wait, aren’t invisibility cloaks just fantasy?
Well … no. Invisibility cloaks could become real. Perhaps sooner than you think.
About Transparency
Generally, only transparent objects are invisible. The question becomes: How do we make a non-transparent object, invisible?
In principle, one could use cameras to record and project images of what’s behind an object onto the object’s surface, making it appear like it’s not even there. This technique generally wouldn’t be practical.
Becoming Invisible
The key to creating a true invisibility cloak may center around metamaterials. These are metal-dielectric composites engineered on the nanoscale. The composite structure acts as an array of artificial atoms, enabling electromagnetic radiation to pass freely around an object. The metamaterial guides light around the object it is coating to create the illusion that the object isn’t there at all.
One challenge up to the present date has been the inability of metamaterial-based cloaking to interact at frequencies, or wavelengths, within the visible light spectrum.
Could this challenge be overcome in the near future? Another issue is whether cloaking could be achieved over a broad spectrum of electromagnetic wavelengths. This may be possible, as this article suggests, albeit requiring heavy reading.
Even if cloaking can hide an object from human sight, sophisticated instruments might detect other effects which could reveal cloaking being used. Perfect cloaking appears impossible. But would it be good enough for concealment from a less advanced society?
In summary, could an advanced extraterrestrial civilization observe us invisibly? Perhaps.
Peter Spasov. Last updated Saturday November 08, 2025
Imagine living in a space station and standing on a tennis court. Your feet remain firmly planted on the ground due to gravity. The court curves slightly upward on the left and right instead of being flat. It’s your serve and you strike the ball, visualizing its trajectory. May your ball land in the service box; otherwise you’ve committed a fault. The ball flies from your racket yet veers from the direction of your strike. What happened?
Welcome to the world of centrifugal gravity.
Becoming a Space Faring Civilization
In the future, humans may venture beyond planet Earth. Several reasons could drive us to do this. Reasons range from an expanding population requiring additional resources to escaping repression on Earth. Otherwise, why leave a ‘paradise’ home to which we had evolved to thrive within? This assumes we won’t ultimately destroy our paradise to become inhabitable. An unfortunate consequence of our technological capabilities is that we could make our world uninhabitable.
Existential risks abound. And let us hope none of these happen. We’d rather not destroy our Earth or society. Otherwise, we couldn’t enjoy playing sports such as tennis.
If a risk became reality, we would be forced to settle elsewhere. Alas, outer space is a deadly environment where we could not live without significant technological assistance. Other planets are also unsuitable for multitudes of reasons. Mars is the closest to being Earth-like—that we know of. Even there, we would need to build pressurized shelters with advanced life support systems. The costs to build a suitable infrastructure are extremely high, especially when considering the costs to deliver materials from Earth.
Alternatively, we could try a ‘live off the land’ approach as proposed by the Mars Society (Or also known as In Situ Resource Utilization.) Essentially, settlers could use local Martian resources and if required, one could mine additional resources from ‘nearby’ asteroids and our moon, where escaping Earth’s gravity wouldn’t be a factor.
Can we do this? Eventually yes but certainly not now. It could take a century or centuries to build up the outer-space mining and manufacturing capability. Opinions vary, ranging from optimism by the Mars Society and the NSS to the less optimistic. For a sobering viewpoint, check out “A City on Mars.”
The Challenge of Non-Earth-Like Gravity
A big unknown for Mars settlement is to live in a lower gravity of one third of Earth’s. Experience with astronauts has shown that zero gravity can cause bone loss among other effects. And we do not yet know the impact of non Earth-like gravity. In particular, we do not know whether human procreation in partial or heavier gravity is possible. And without procreation, what future is there for tennis?
One prudent approach is to settle where gravity is similar to Earth’s. But few other planetary alternatives potentially exist. Being light years away, we do not know yet if other factors may rule out these alternatives. Besides, all of them have gravity differing considerably from Earth’s.
Why Would We Live in a Space Station?
If one rules out planetary possibilities, this leaves us with artificial possibilities. Since the early 20th century, some theorists have suggested space stations. The type we will focus on here is the O’Neill cylinder,
Welcome to the O’Neill Cylinder
This animation will give you an idea of the interior of an O-Neill cylinder. Certainly looks like one can build a tennis court in it.
A pair of O’Neill cylinder consists of two counter-rotating cylinders. The cylinders would rotate in opposite directions. Without the counter rotation, it would be difficult to obtain the sunlight required for power. And without power we cannot sustain a tennis-playing culture. For now, we’ll ignore alternative power sources, such as nuclear reactors. Besides, we need a sufficiently large population of people for sustaining a long-term society.
Generally each cylinder would be 6.4 kilometers (4 mi) or 8.0 kilometers (5 mi) in diameter and 32 kilometers (20 mi) long, connected at each end by a rod via a bearing system. Their rotation would provide artificial gravity.
Among other things, the large dimensions are necessary for reasonable gravity generation. To understand how gravity is generated, we’ll need to consider some physics. Sorry about that.
Remember Newton? He told us that force causes mass to accelerate. More precisely, the amount of force on an object equals an object’s mass multiplied by its acceleration. Acceleration is not just speeding up or slowing down. An acceleration can also be a change in the direction of motion.
About Space Station Rotation
Guess what? Rotation is a change in direction. This means rotation is also acceleration. It turns out that acceleration causes one to experience a fictitious force, where the term fictitious force is a physics term referring to a force resulting from acceleration, instead of a force which causes acceleration.
If you’ve ridden a Graviton at a carnival, you’ve certainly felt pushed against the inside wall of the ride. Nothing fictitious about that feeling! That force is centrifugal force. Similarly when an O’Neill cylinder spins, a centrifugal force pushes you against its inner wall. The force feels like and sort-of acts like gravity pulling you to the ground.
The strength of centrifugal force increases with the radial distance from the axis of spin and with the square of angular velocity. You probably know from experience that spinning at high speeds can make you throw up. So how fast can people spin comfortably? (See answer #13)
According to some research, a revolving speed of one revolution per minute (RPM) can be sustained comfortably. This means that in order to achieve a force sufficient for Earth-like gravity, one needs a larger radial distance. Hence the size of the station must increase, for example a cylinder diameter of 6.4 km.
Although living in an O’Neill cyclinder would be like living in gravity, there are some differences.
The Weird World of Spinning
When you walk on the Earth, you don’t notice a force pushing you sideways. It exists though, but it is too small to notice. Whenever something moves on a rotating surface the object experiences a coriolis force. Because the Earth rotates, this force affects ocean currents and cyclones. The preceding link shows the coriolis force as acting sideways when one is standing on a spinning disk. When standing on the inner surface the coriolis force direction will depend on spin direction and on which direction the object moves within the cylinder.
This means a sufficiently fast tennis ball will experience a coriolis force, unless the ball moves parallel to the spin axis. As the ball’s angle of direction (away from parallel) increases, the coriolis force increases for any given ball speed. When the ball moves perpendicular to the spin axis, it will experience the maximum possible coriolis force for any given ball speed.
If the velocity is parallel to the rotation axis, the Coriolis force is zero. For example, on Earth, this situation occurs for a body at the equator moving north or south relative to the Earth’s surface. Within an O’Neill cylinder, the spin axis runs along the centre of the cylinder. If one places the tennis court to run along the side, to make longer sides parallel to the spin axis, the coriolis force becomes zero if the ball travels purely parallel along the side of the cylinder. Making the ball fly at an angle however causes a non-zero coriolis force.
Simulation
Here is a simulation of a ball sent flying from within a spinning cylinder. Left click to shoot the ball. Press escape to stop the simulation. To shift the position of start location use one of W, S,A or D keys. Try to shoot the ball. Notice how the ball deflects.
You can also use the Tom Lechner simulation to see some of the effects of throwing a ball along the wall. A tennis court should be meshed in completely during play. Otherwise some balls may escape to inward within the cylinder, or otherwise bounce within the cylinder.
For a more detailed look at coriolis force, including direction, refer to a UBC physics note which also describes the right hand rule. In summary, use your right-hand thumb to point along the axis of rotation. By physics convention, the positive rotation axis would be spinning counter clockwise. The index finger points in the direction of the object (ball in this case) velocity. The middle finger would point in the direction opposite of the coriolis force (due to a negative sign in the mathematical derivation).
For a spinning cylinder spinning counter clockwise, hitting the ball towards the end results in a coriolis force pointing left, resulting in a leftwards deflection.
Would the Coriolis Force be Noticeable?
When we walk on Earth, we don’t notice the coriolis force due to our slow speed relative to the large size and spin rate of the Earth. Would the effects be noticeable while playing tennis in a ‘typical’ O’Neill space station?
I did a crude calculation to ascertain this. I used a cylinder spinning at 0.6 revolutions per minute and with a diameter of 6 kilometers. I considered a player hitting the ball from corner to corner in a standard doubles court. Furthermore this person sent the ball flying at 225 kilometers per hour.
The resulting acceleration from the coriolis force would be about 0.14 g (g being acceleration due to gravity on Earth). After one second the ball would have diverted from a straight line of travel by about 70 centimeters. This would be noticeable.
I imagine a player would also notice the force pushing sidewise upon them while running about on the court, but I haven’t done any calculations in order to assess this.
Peter Spasov. Last updated Saturday October 04, 2025
Philosopher’s stone as pictured in Atalanta Fugiens Emblem 21
Oldest golden artifacts in the world (4600–4200 BC) from Varna necropolis, Bulgaria — grave offerings on exposition in Varna Museum.
The Ultimate Transmutation Machine
For centuries, people have valued gold. The oldest gold artifacts date back to the 5th millennium BC. People have long sought the magic of making this precious element.
What if one could convert lead into gold? The short answer is yes. Alas, the answer comes with a lot of gotchas. A second question follows: Would one want to?
More universally, what if one could transform any element into another element? Imagine turning nitrogen into platinum. Could future people make an ultimate transmutation machine? Would it be desirable? Let’s find out.
The Lure of the Philosopher’s Stone
Early chemists, also known as alchemists, tried to turn cheaper metals into gold, a process known as Chrysopoeia. These chemists were in search of ‘the philosopher’s stone,’ a magic substance for the purpose of converting something else into gold. Surprise, they never found it.
However, recent scientists have managed to make gold, but by spending much more than gold is worth. But, could a future society produce gold economically? And if it did so, what would this do to the value of gold?
Before answering these questions, we should consider how gold ended up in our universe in the first place.
Back to Basics, the Elements
Elements compose all matter in universe. They range from the hydrogen atoms produced shortly after the big bang, all the way to the most complex moleculeever made (so far). All molecules are made from the elements, and the elements are hydrogen (the lightest), helium, lithium, and so on … all the way up to oganesson, which is so far the heaviest element.
What? You’ve never heard of oganessson? Now you have.
Remember the periodic table? Of course you do. Reminds you of school, I bet.
In short, all elements are made from the stars. Remember the line from the Woodstock song, We are Stardust? Joni knew where we all came from. Hear the song here.
If nature already produces gold, why bother making it? Good question. If the universe has gold, space venturists could go out there and mine it. Right?
Billions of years later, gold from the stars ended up as deposits on Earth. For instance, an ancient asteroid (or asteroids) may have seeded the Witwatersrand basin in South Africa to become the richest gold deposits on Earth. For more refer to the Origin section on Wikipedia’s page about gold.
Perhaps one might find more gold deeper into the Earth’s interior. An enterprising futurist could drill deep into the Earth’s mantle to extract it. Or look for gold-bearing asteroids. In a space epic, the hero could visit the remains of merging neutron stars. Somewhere in that neighborhood, one might find gold-bearing asteroids. Perhaps.
Given the daunting task of making a go at interstellar mining, let’s consider the gold fabrication option.
Making Gold from other Atoms
So far, two laboratories have produced non-radioactive gold. Seaborg’s laboratory blasted the bismuth inside a particle accelerator. It did so by using carbon and neon nuclei to remove protons and neutrons from bismuth atoms.
A bismuth atom has 83 protons and the bismuth-209 isotope has 126 neutrons. The nucleus of the common stable gold-197 isotope has 79 protons and 118 neutrons.
CERN, the largest particle accelerator facility in the world, produced gold from lead. In an ALICE experiment, near-miss collisions between high-energy lead nuclei produced small amounts of gold nuclei.
Both of these methods utlized high energies and expensive facilities, and both only produced only miniscule amounts at very high expense. So, how is a sci-fi writer going to world-build an economic method of making gold?
A Universal Machine
One could conceive of a universal element maker, banging protons and neutrons together to form any element, including gold. The machine would also need to supply electrons for each atom in order to match the number of protons. But wait, there’s another possibility.
Use neutron capture followed by beta decay. In neutron capture, the electrically-neutral neutrons collide and bind with an atom’s nucleus to make the atom heavier. Eventually beta decay occurs, during which the atom emits beta radiation – and – a neutron transforms into a proton by switching a ‘down’ quark into an ‘up’ quark. Quarks are the basic constituents of matter, forming sub-atomic entities such as protons and neutrons.
Perhaps some exotic new technology would manipulate quarks more directly? I’ll let a physics guru answer. If this were possible, a machine could transform a neutron into a proton, or vice versa, by switching the appropriate quark.
Perhaps this machine would use photons to ‘manipulate’ the subject quark, such as by using gamma rays. It is hard to manipulate something smaller than an atom by using a component made of atoms. That would be harder than fixing a precision watch while wearing heavy gloves. Regardless, if some future means is found, the process will be highly energy intensive.
In theory, this all sounds good. Alas, any process would be highly radioactive and energy costly. Will any culture be capable of economically running such processes? Enter the highly-advanced civilization. Specifically, meet the Kardashev super civilization.
A Kardashev Super Civilization?
The Kardashev classification system labels civilizations in terms of how much energy a society utilizes. Within a few centuries, humanity might achieve a Type I level, whereby a societ harnesses all available energy on the home planet. But to achieve economic transmutation of elements, the civilization may need to achieve Type II at minimum. At Type II, the society utilizes the entire energy of its host star. In our case, use our Sun.
For Type III, the civilization utilizes the entire galaxy. Mind boggling.
Assuming such civilizations could exist, a future society may produce gold by utilizing the virtually-unlimited energy at its disposal. However, what would happen to the value of gold? It appears the real value for advanced civilizations should be based on energy, not gold.
Let’s look at why gold is valuable now, and why it might not be valuable in a future society.
The Future Value of Gold
Generally, gold is valuable because it is sufficiently rare while also being durable, beautiful and easily recognizable. Hence society has used gold as a basis for currency although changes have occurred.
Rareness is important for making something valuable. When was the last time you spent a fortune to purchase pepper to go along with your salt? If you have the resources to read this website, you probably don’t spend a lot of money on pepper. However, there was a time when pepper cost a fortune. Long ago, due to the difficulty of pepper cultivation plus its high demand, pepper had been a basis for currency.
How should currency be set? This is a loaded question leading to debate. Seeing how energy defines the advancement level for future civilizations, should there be an energy-based currency? As valued commodity, will gold become passé?
Afterword
King Midas suffered because turning everything into gold made it worse than worthless, making this material literally toxic. Consider the lesson.
Milky way as seen from Earth. Our Milky Way is about 87,000 light years in diameter. Image By Steve Jurvetson – Flickr, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=23906915
First novel to use an ansible, a fictitious device to communicate over light years within a ‘reasonable’ time. Image by http://www.fantasticfiction.co.uk/images/n5/n29016.jpg, Fair use, https://en.wikipedia.org/w/index.php?curid=8376317
Running your Interstellar Empire
What if future technology permitted blasting at Faster than Light (FTL) were possible? It has to be. Otherwise how could we suspend our disbelief when it comes to epics of galactic empires? Such as Asimov’s Foundation series, where a psychohistorian predicts a long dark period of about 30,000 years after the inevitable fall of an empire encompassing the entire milky way.
Or you enjoy the Star Trek series or maybe you are more of a Star Wars person. In all of these, one can communicate nearly instantly with settlements in distant star systems. One can physically travel amongst them multiple times within a person’s lifetime.
Perhaps you wish to create a story set in a similar scenario. Alas, science says no communication or physical travel can exceed the speed of light. Is this a problem? Well, let’s see. Light travels at 300,000 kilometers per second. Mighty fast, right?
Depends. Light from our closest neighbor star takes over four years to reach us. Our galaxy, the Milky Way, has 100-400 billion stars contained within a spiral cluster of 87,000 light years in diameter. Sending a message from one end to the opposite end takes 87,000 years. Physically travelling, according to science, must take longer. Only massless particles, such as photons, can travel at light speed.
Alas, the quartz mountain link misspeaks regarding massless particles having zero energy. The article should have stated zero ‘kinetic’ energy. Photons have ‘photon energy’ according to electromagnetic frequency (or wavelength).
Enough said about science. Seems light speed isn’t so fast. Does it?
What are the implications? If your hero must fight at the opposite end of our galaxy, she couldn’t. When your hero first hears about the fight, the fight began 87,000 years ago. The fight had probably ended by the time your hero first hears about it. But if FTL communications and travel were possible, your hero could join the fight.
What’s the answer to creating a story spanning a galaxy? Simple, permit FTL communications and travel. Many authors do.
“But hold on there, Mister Spoiler,” you might say, “I want to stick to the plausible.”
Could you?
Depends. Let’s find out.
Is FTL Possible?
Conventional science states the universe must have a speed limit and this happens to be the speed of light. Most accepted physics says so. To quote Why Is There a Maximum Speed Limit in the Universe?, “And so it is for the cosmic speed limit; we cannot make it speedier.”
But, wait. What about the expansion of space? Objects located 14 billion light-years away from us, recede from us at a speed of 300,000 km/s, or just about the speed of light. An object 33 billion light-years away recedes at a speed of 708,000 km/s, or more than double the speed of light. Wouldn’t this contradict the claim of light speed being the maximum possible?
The situation of our expanding universe is more subtle. The Big Think article states: “In reality, these objects aren’t moving through the Universe at that speed at all, but rather the space between bound objects is expanding. The effect on the light is equivalent — it gets stretched and redshifted by identical amounts — but the physical phenomenon causing the redshift is due to the expanding Universe, not from the object speeding away through space.”
We could interpret this to mean the speed limit only applies to moving relative to space. There is more however.
Sabine Hossenfelder, a popular science communicator and YouTuber argues extensively why FTL is possible. Warning, the argument is quite extensive. I summarized the essence of her argument below.
According to Sabine Hossenfelder, Einstein’s theories do not imply that faster than light travel is forbidden. The problem is that one cannot accelerate from below the speed of light to above the speed of light. A second issue, she claims, is that mathematical infinity for something doesn’t imply an physical impossibity. This apparently applies for mathematics regarding black holes, which most scientists say do exist. Her third point is that there is a counterexample for an object with any mass requiring an infinite amount of energy to reach the speed of light.
Her third point concerns the nature of matter and the nuclear forces holding an atomic nucleus together. People, technically, are almost entirely made of pure energy. Particles have matter only if they get dragged while moving through the Higgs field. In the early universe none of the particles had mass and could move at the speed of light. Later, they could not. Perhaps something can be done about this Higgs field? Which Sabine does not recommend.
She also discusses time paradoxes, in which she argues there’s nothing weird about you being able to deliver a message to your younger self. She states Einstein’s special relativity (where time paradoxes apply) doesn’t apply to reality because special relativity doesn’t contain gravity. Einstein’s general relativity includes gravity, however. Sabine goes on to argue why time-travel paradoxes do not apply to our universe, yet is consistent with general relativity.
Finally she argues that general relativity is incomplete because a theory of quantum gravity is yet to be developed. Sabine isn’t alone in her assertions. Astrophysicist Erik Lentz argues FTL is possible for different reasons.
Although massed particles cannot travel at FTL, space-time can. He suggests the possibility of bending space-time into a bubble of negative energy. There are too certain theoretical ways to employ negative energy for FTL. Lentz also mentions a new class of hyper-fast solitons – a kind of wave that maintains its shape and energy while moving at a constant velocity (and in this case, a velocity faster than light).
Hypothetical Methods for FTL
Here, I will quote from a Wikipedia article about FTL to list possible methods. “Speculative faster-than-light concepts include the Alcubierre drive, Krasnikov tubes, traversable wormholes, and quantum tunneling. Some of these proposals find loopholes around general relativity, such as by expanding or contracting space to make the object appear to be travelling greater than c (symbol c means speed of light). Such proposals are still widely believed to be impossible as they still violate current understandings of causality, and they all require fanciful mechanisms to work (such as requiring exotic matter)” Italics are mine.
Because many have already offered much on the topic, I list some other links I’ve found informative because they are more recent.
Given that some scientists have offered the plausibility of FTL, writers, can justify using it. In my opinion, a serious writer, when choosing a particular method, must work out the implications in their particular world setting.
For instance, some paranoid cultures on Earth have been ramping up their defenses against possible alien invasion. They’ve even built in a pre-emptive strike capability. Hooray, feel safer already?
Our hero notices that a star system located 500 light years from us shows signs of civilization. “Aha,” he says, “we should launch a strike.” The fleet launches with its FTL capability and arrives at the exoplanet within a month.
When they arrive, a big surprise awaits them. No civilization exists but there are ruins of a technological civilization that must have collapsed, maybe 400 years ago. Because of the 500 light-year distance, Earth had been observing that exoplanet 500 years in the past–when the civilization used to exist.
But what if that civilization hadn’t collapsed? What if they too had already launched an invading fleet with similar FTL capability? Perhaps that fleet had already arrived? Or maybe they arrive before Earth manages to launch its fleet. In these scenarios, each party doesn’t know whether the other will attack but assumes they will. This doesn’t help with peaceful coexistence.
With FTL, one will always arrive at the destination’s past. If FTL communications became possible, there would be an odd disconnect with communicating near-present information while observing the other party’s past through astronomical observation. Strange scenarios indeed.
Olympus Mons photo taken at unknown altitude above Mars. Mountain width of about 624 km, the size of Arizona or France. Image source Wikipedia
Mount Everest on Earth. Mountain width is about 40 km. Image source Wikipedia
The Call to Adventure
What if you could ride a mountain bike on Mars? Why would you?
“For adventure,” I’d say. “Imagine riding to the top of the largest mountain in the solar system?”
“I know,” you might say. “That would be Olympus Mons.”
Let’s get started, a high and mighty adventure. You imagine craggy rocks stretching high to the sky, adrenaline pumping while peddling your Salsa Horsethief Deore over shear granite. You’d push your way beyond the snow line. Except Martian mountains have no snow line or granite.
“Well, isn’t that swell,” you say, “but riding it could still be thrilling.”
For now, we’ll consider a near future scenario when people are exploring Mars in a manner similar to contemporary Antarctica. What if riding the mountain wouldn’t quite be the thrill you might expect?
To Peddle or not to Peddle
You say. “But isn’t Mars a cold and oxygen-less hell? Wouldn’t riding while wearing a bulky spacesuit make peddling overly exerting? Wouldn’t I quickly run out of air?”
I reply. “Yes.”
“Then why peddle?”
“You’ve got a point. I’d suggest an e-bike.”
You ponder. “Wouldn’t that be cheating?”
I grin. “Consider cheating as a necessary Martian survival trait.”
Geography of Climbing Olympus Mons
Recently I wrote a story about astronauts climbing Olympus Mons. Leaving aside story merit, let’s look at how near-future technology might be employed for this venture. First, we need to look at the setting. One can virtually explore Olympus Mons by downloading the free Google Earth desktop program or app. In addition to exploring Earth the program allows one to explore parts of outer space including planet Mars. With the program, I could trace various paths and see cross-sectional elevation changes. The data used for modeling is taken mostly from NASA sources.
Olympus Mons rises to an altitude above 21 km (13 miles or 69,000 feet). Its highest point is at 21,287.4 meters, as measured by the MGS laser to a precision of 10 centimeters. Mount Everest, by comparison, peaks at an elevation of 8,848.86 meters.
With a summit the size of France, riding at the top would be boringly flat, unlike the daunting slopes of Mount Everest. The easy path is to follow the flatter path shown starting at Archive Cache and ending at the summit. Along that path, the steepest slope is eleven degrees. This is comparable to a two over twelve roof pitch.
For a more challenging path let’s try riding up the daunting cliff, beginning at Olympus Mons Cache. Crazy eh? Let’s zoom in and take a closer look.
Google Earth view of Olympus Mons at an altitude of 1302.71 km
Google Earth view of cliff face of Olympus Mons at an elevation of 179.47 km. Image source is a screen snip of the Google Earth program taken by the author.
Mount Everest as shown by Google Earth at an altitude of 179 km. Mountain width is about 40 km. Image source is a screen snip of the Google Earth program taken by the author.
When we zoom in to the cliff face, we can see the view as illustrated to the right, showing a portion of the cliff if we were looking from an altitude of 15.25 km. The red lines are ‘paths’ which one can create with Google Earth program (but remember we’ve set Google Earth to show Mars!).
We’ll use the second line from the right to represent our adventure climb. Appropriately, I labeled this path as SteepClimb.
What would be its elevation profile?
Shall we take a look?
Here, I’ve use the Google Earth elevation profile feature. I’ve marked a steep point with a grade of 45.6%, meaning the slope of climbing 45.6 vertical meters over 100 meters of horizontal travel. As an angle this would be 24.5 degrees. (For the math, take the inverse tangent of the fraction of 0.456). Doesn’t look like 24.5 degrees, does it? That’s because maps and globes generally exaggerate the vertical dimensions. If one shrunk Earth to the size of a billiard ball, it would be very smooth, but would still make a poor billiard ball.
This is Google Earth’s elevation profile for the ‘steep climb.’ Doesn’t look quite as steep does it? Still, this would be tough slog with a mountain bike or an e bike. For comparison, below is a cross cut for a section of the Grand Canyon on Earth. The steepest grade here is about 90% or 42 degrees. By zooming in and exploring more, one could probably find steeper sections in the Grand Canyon. Notice the Grand Canyon profile shows a horizontal length of 718 m compared to the horizontal 14 km for the steep climb for Olympus Mons.
In summary: Whereas the central part of the Olympus Mons exhibits slope angles of less than 1 to 5°, the periphery of the edifice terminates with steep cliffs sloping 12–15° up to 28°.
There is another factor making the climb on Mars easier than on Earth. Mars gravity is one third of Earth’s and the air is very thin. The atmospheric pressure on Mars is one hundredth that of Earth’s. This means lower weight and less air drag for the e bike to handle.
By further zooming in, I found a steeper section on the Olympus Mons steep climb path to be 27 degrees. Hence I used this as my steepest slope for my story.
About the Mars-Climbing E Bike
Confession. When I cycle, I generally cycle on flatter terrain. Hence I examined some specifications for commercially available mountain bikes or e bikes. I would use these as a baseline to define some possible specifications for a Martian bike that could exist in the near future. Perchance I could world-build an e-bike with improved capabilities.
One electric motorcycle caught my attention, the Sanya UF-X(SY4000D). This electric bike’s general specifications are 4000 W brushless motor, 72V52V lithium battery, Max speed: 92km/h, Max range:120 km based on 45km/h speed. Its climbing ability on Earth is claimed to be 17 degrees. Could it handle 27 degrees on Mars? Anyone want to give this a try?
I visualized what the bike might look like and gave it a (backstory) product name of Roughneck Mangala, where Mangala is Sanskrit for Mars. During my research, the most suitable role models appeared to be bikes used by hunters. I don’t hunt for sport but I do admire the bush-suitable technology which hunters use for dragging out the big game they may have downed. Here is a one commercial photo. I would extrapolate the bike appearance for a Mars scenario, one where the rider would be wearing a space suit. As for the archery equipment, I didn’t use arrows for my story.
The Mangala bike would use a motor for each wheel for improved traction and control. The cargo trailer would be essential for carrying required supplies.
Here are the bike characteristics I chose. I believe these would be feasible for a Mars capable bike in the near future. The cruise speed and range would apply for flat ground.
Bike Cruise
50
km/hr
Range
150
km
Bike+trailer+battery
75
kg
Mass loaded w rider
295
kg
And its battery. A rider would need to swap or recharge batteries as required.
Battery
72
V
75
Ah
Energy
5200
Whr
Mass
15
kg
The specifications would set restraints for the trip to the summit and back.
Tires
Pneumatic tires provide more comfort, more stability, better suspension, better climbing, faster speeds, more traction, and better control. The only advantages of solid tires are not getting flat tires and less maintenance. Only choose solid tires if you live in a place with poor roads, where you may get a lot of flats.
Yet I chose solid, surmising high-tech material to give traction and pliability. Check out Bridgestone’s and Michelin’s concepts for solid tires.
The Journey
I selected a mass of 295 kg for each suited astronaut riding a bike with 50 kg of cargo. In my story, two astronauts with cargo undertake the trip from a cache location near the cliff face of Olympus Mons. Here are some packing requirements and trip logistics as pasted from my spreadsheet. I used the spreadsheet for calculating time durations and battery swapping events.
Astronaut daily water
4
L or kg
Astronaut daily food
1
kg
Design expedition length
5
days
An EVA suit is good for 1.5 days.
Normal ops is that each overnight stay is at a cache, where air tank replaced next morning
But only one overnight req’d
During outbound, each person brings 3 additional batteries to swap along the way
Leave at all used batteries at summit along with solar charger (that was air dropped)
A third astronaut flew a shuttle vehicle to air drop supplies to a cache point near the mountain summit. In the story, the trip required only one and a half days, including a side trip to the caldera of Olympus Mons. The calculations involved energy consumption of the batteries, taking into account the average slope of various segments of the trip. Generally I used grade 12 high-school level physics. Similarly I worked out oxygen consumption needs as required for the trip. The space suits are designed to provide up to one and half days worth of oxygen. For a design expedition, one need additional oxygen tanks for the EVA suits (EVA is a fancy way of saying spacesuit, an acronym for Extra Vehicular Activity)
After this trip other travelers could reuse the batteries left at the summit. They could recharge them by using the solar charger.
The trip required one overnight stay close at the summit. The summit (highest point) of Olympus Mons is about 29 km distant from the caldera. Because the top part of Olympus Mons has a very shallow slope, the peak would appear to the astronauts as a flat expanse. They would see a desert of rock resembling the flat of a prairie in the Canadian or American mid west. With the top part of Olympus Mons as large as France, they would see only flat (and maybe some boulders) to as far as the horizon. The mountain’s edge would lie far beyond the horizon. Compared to Everest, riding the top portion of Olympus Mons could be boring.
For an exciting story, one needs other dramatic elements.
A Word about Martian Camping
With one overnight stay, I imagined an inflatable tent. One issue for Martian exploration is perchlorates on the surface. Perchlorates can be highly toxic, hence one wouldn’t want to bring perchlorates inside a tent.
One key difference for Martian exploration is to pressurize the tent for air and to keep out the damn perchlorates. A compressor, regulators and air tank can handle the former. As for keeping out the perchlorates, keep the spacesuit outside and use the suit as an airlock. The basic idea is the suitport concept. Getting such a concept to work for a tent is more challenging than I could envision for the more solid structures as shown in the Wikipedia article, which apparently involved an airlock chamber.
EVA Access procedures using the Suitport, as pasted from ‘The Suitports_Progress.pdf’
Instead, I envisioned a spacesuit that is vertically stretchable such as a bellows at the waist and connector at the chest. Generally the astronaut connects their suit’s chest connector to the tent’s connector. By knee bending and other contortions an astronaut crawls out of their suit to enter the tent. To exit the tent and re-enter the spacesuit, the astronaut needs to enter feet first, an athletic feat indeed. That said; should faint-hearted non-athletic people go camping on Mars?
There are other bodily needs for eating, drinking, and waste disposal which need addressing for the trip and are part of the back story, if not addressed directly in the story.
More about the Camping Suitport
This section is part of my notes, and reading it would be a long slog. The notes are a result of pure imagination. Of course, one would need to fine tune it or dramatically modify to get the system to work. Don’t say I didn’t warn you. Disclaimer: I cannot draw very well.
Entry Procedure
The tent has two access points at chest height. Each suited astronaut approaches their access point facing forward. The spacesuit has a mating ring located below the chest and above the waist that protrudes out. The astronaut positions ring to align with the tent’s access port and locks both together using suit gloves. Open access door. Such as; by pressing external button with gloved hand, permitting free airway passage between suit and tent interior. For the suit, tongue-in-groove matched surfaces slide apart to protrude beyond the sides. The tent’s access port door operates similarly. Air pressure inside tent would equalize with air inside suit.
Astronaut stretches hands and arms straight up vertical as shown in figure 1.
[ Fig. 1 ]
Astronaut bends knees akin to a squat or a Tai Chi Danyu, to extend bellows in order to drop upper body while suit’s top portion held in position by the access port. Squats downwards until head level with the access port as shown in figure 2. Also, astronaut can clear arms and hands from the sleeves and squeeze them into position to grab within the access port.
(With bent knees and bellows extension, drop in head height likely to be 30 inches or more.)
[ Fig. 2 ] PLSS = Portable Life Support System
(Hu is my invented gender-free pronoun to replace she/her or he/his)
Hu bends to begin crawling through tube with hands and arms first followed by head. There may be handholds to assist. While crawling into tube, Hu raises self up with knees. As knees straighten, Hu’s upper body will have stretched out past the tent wall. Hu bends down towards floor, stretches out the hands towards the floor and proceeds such that hands contact the floor. With knees again straightened, walk the hands forward to pull feet and legs upwards to clear the suit and into the tube. Proceed until feet clear the tube and drop them onto the floor. Suit exoskeleton controls may lock joints into a parked position (or not) so as to resemble figure 1.
The mechanisms will have sufficient flex to facilitate entry into the tube (and vice versa for exit). The diagrams are only illustrative. The bellows portion would probably be at an outward lean. There might also be swivel ability with the mated ports to permit leaning upper portion of suit as required.
To re-enter Suit from inside Tent: (one astronaut at a time)
Tent has a pre-packed collapsible tripod which is multifunctional to hold stove etc. Position assistive tripod and face away from access point. Place hands on tripod and kick feet up to land within access point. Alternatively, walk feet upwards along a ‘fabric’ ladder while holding onto tripod. While holding onto tripod, walk/hop tripod towards access-point wall while shimmying feet and legs further into access point and work feet and legs down into spacesuit waist and legs until it will be necessary to let go of the tripod. (At this point the last astronaut to exit would collapse the tripod prior to letting go and leaving it on the floor.)
Alternatively, have a scaffold system to lie upon. But this would require a self-collapsing mechanism for the final exiting astronaut to trigger.
Proceed to shimmy feet further into suit with assistance of pushing with hands when possible. Exoskeleton controls might assist to orient lower suit torso and operate bellows as required. Shimmy until feed have landed inside the boots so as to be in position with bent knees as per figure 2. Astronaut positions hands to enter sleeves and straightens knees to place hands through suit arms and into gloves to be position as per figure 1.
Astronaut can drop arms to press external button to seal the doors again and then unlock the mated connections.
Other Notes
Note the tent has already pre-packed with items such as sleeping gear, compost bag, electric heater-stove combo, pre-filled ice containers (to melt into liquid water and boil for cooking), lighting, sanitary wipes, multipurpose tool (akin to Swiss Army knife), radio remote and other stuff. There is an electrical connection to batteries (or other power source) located external to the tent. Similarly there is a connection to an external air supply system compressor/deflator combo. The unit circulates the air so as to scrub CO2. The radio remote is used for remote manual control of external items including a longer-range radio sufficient for Mars-wide communication including near-Mars orbit.
