Space Travels to Nearby Exoplanets: Any Possibility (Part 5)

Instead of travelling far too far, what about some nearby exoplanets – planets that exist outside our Solar System? How many of them have been discovered?  Could life exist on newly discovered exoplanets, and can we go there?

There are thousands of exoplanets discovered so far, with many in the habitable zone (where conditions might support liquid water). Some promising candidates include:

Proxima Centauri b (4.24 light-years away) – A rocky planet in the habitable zone of Proxima Centauri, though it is bombarded with strong stellar radiation.

The TRAPPIST-1 System (~39 light-years away) – Seven Earth-sized planets, at least three of which are in the habitable zone.

Kepler-442b (~1,120 light-years away) – A super-Earth that receives enough sunlight to potentially support life.

Although we haven’t confirmed life on any exoplanet yet, scientists use methods like spectroscopy to analyse their atmospheres for biosignatures such as oxygen, methane, and water vapor. Future telescopes, like the James Webb Space Telescope (JWST), are designed to study exoplanets in greater detail.

 

Can We Travel to the Nearest Exoplanets?

Theoretically, reaching the nearest exoplanet (e.g., Proxima Centauri b) is possible, but with current technology, it would take thousands of years. Here are some of the reasons.

Current limitations with conventional rockets are the fastest spacecraft ever launched, Voyager 1, travels at ~17 km/s. At that speed, it would take over 73,000 years to reach Proxima Centauri. The we also have fuel constraints of carrying enough fuel to reach high speeds is a major problem. Consider survival in space even to the nearest exoplanets since  human lifespans and exposure to radiation pose significant risks for long journeys. Some possible future solutions include a breakthrough Starshot, namely a proposed mission to send tiny, laser-powered probes to Alpha Centauri at 20% the speed of light, reaching it in 20 years. Technologies like nuclear pulse propulsion or fusion propulsion rockets could cut travel time to a few decades. We have earlier talked about warp drive concepts that are theoretical physics that suggests space-time manipulation (e.g., Alcubierre drive) that could enable faster-than-light travel, but it remains speculative.

We have also suggested generation ships or cryosleep if journeys take centuries, humans might need to live on self-sustaining "ark ships" or enter hibernation.

While even traveling to the nearest exoplanets is currently beyond our technological reach, future advances in propulsion, energy storage, and space travel may eventually allow us to explore them. The search for life continues, and if we detect signs of extraterrestrial life, it may push humanity to develop new ways to reach the stars.

Technologies That Could Enable Travel to Exoplanets

Travelling to exoplanets is one of the greatest challenges humanity faces. Our current propulsion methods are far too slow, but there are several theoretical and experimental technologies I have written earlier that could make interstellar travel a reality. Just to recall, below are the most promising approaches:

 

Near-Term Technologies (Could Be Developed in the Next 100 Years)

Breakthrough Starshot (Laser-Powered Light Sail) This concept lies on tiny spacecraft (gram-sized "StarChips") with light sails propelled by powerful Earth-based lasers. Speeds up to 20% the speed of light (~60,000 km/s) is possible. The time to Proxima Centauri (4.24 light-years) is 20-30 years. But the challenges are that it requires enormous laser arrays on Earth, risk of damage from interstellar dust, and difficulty in slowing down at the destination. However, the physics is well understood, and the technology is already being researched.

Alternatively, we can also consider using nuclear fusion rockets (direct propulsion). The concept here uses controlled nuclear fusion reactions (like the Sun) to generate immense thrust. The speed we can expect is 10% the speed of light (~30,000 km/s). The time to Proxima Centauri is 40 years. The challenges are it requires advanced fusion reactors that don't yet exist, plus enormous energy storage. If we master nuclear fusion for energy, it could also power rockets. Projects like NASA's Direct Fusion Drive (DFD) and Project Daedalus study this approach.

 

I have also earlier suggested using antimatter propulsion. The concept is,  matter and antimatter annihilate to produce pure energy (E = mc²), providing extreme thrust. The speed we can expect is up to 50% the speed of light (~150,000 km/s). The time to Proxima Centauri is  8-10 years. The challenges are, antimatter is extremely expensive to produce and store safely. It is probably the most energy-efficient propulsion possible, but we lack the technology to produce antimatter in large quantities.

Far-future technologies (100+ years away, but theoretically possible. This are

Alcubierre warp drive that goes faster-than-light travel). The concept is, it compresses space ahead of a spacecraft while expanding space behind it, allowing "faster-than-light" travel without breaking relativity. The speed theoretically is many times the speed of light.

The time to Proxima Centauri is instantaneous (in principle). But the challenges are that this requires exotic negative energy (which may not exist), and controlling space-time warping is beyond our current physics. It is promising that if negative energy fields or advanced quantum field manipulation become possible, warp drives could revolutionize travel.

I have already written about using Einstein- Rosen bridge or wormholes (space shortcuts) where the concept is,  hypothetical tunnels through space-time that could connect distant locations instantly. The speed is instantaneous, and the time to Proxima Centauri is just a few seconds (if stable wormholes exist). Unfortunately, currently we do not know if wormholes exist naturally or how to create them, and keeping them stable requires exotic matter. If wormholes exist or can be artificially created, they could enable true interstellar travel.

Regardless of propulsion, long-duration space travel requires additional technologies, including generation ships that are large self-sustaining space colonies where multiple generations live and die before reaching an exoplanet. Our challenges require perfect ecosystem balance, long-term social stability, and massive engineering efforts. But it allows slow travel over thousands of years while keeping humans alive.

In that case, we need to revert to cryogenic sleep (biostasis) where the concept is  deep freezing or slowing down human metabolism for long-duration space travel. Fortunately, our challenge is, we haven’t perfected human hibernation, and long-term effects are unknown. If we solve human biostasis, we could "sleep" through a long journey.

Can we reach exoplanets then? Yes, but not with current technology. The best near-term option is laser sails (breakthrough Starshot), while nuclear fusion or antimatter propulsion could make human travel practical. In the far future, warp drives or wormholes could revolutionize space travel - ah, provided they are physically possible.

I have already written about  wormholes as a hypothetical tunnel connecting two points in space-time. It was first proposed as a solution to Einstein's General Relativity equations by Albert Einstein and Nathan Rosen in 1935 (hence called an Einstein-Rosen Bridge). The key properties of Wormholes are, they connect distant locations in space, potentially allowing instant travel between them.

They could also connect different times, making time travel a theoretical possibility. They are predicted by Einstein’s equations, but we have never observed one.

I have earlier explained if we imagine space-time as a piece of paper. If you fold the paper and punch a hole through it, a wormhole will act like a tunnel connecting two points on the paper, bypassing the usual long route. A wormhole could be used as a time machine to travel backward in time. The challenges of using wormholes for Time Travel while  sounds exciting, there are serious obstacles to making a wormhole a real time machine, first, do wormholes even exist? My answer is, no natural wormhole has ever been observed. Theoretically, they could form in extreme space-time conditions (like inside black holes), but we don’t know if nature allows them. Keeping a wormhole open requires exotic matter. Einstein’s equations suggest that wormholes might collapse instantly unless held open by negative energy or exotic matter (which violates normal energy conditions). Some quantum physics theories (like the Casimir Effect) hint that negative energy is possible, but we don’t know how to generate enough of it.

 The Paradox Problem (Grandfather Paradox).

If we use a wormhole to travel back in time and change the past (e.g., stopping our grandparents from meeting), we create a causality paradox. Solutions like the Novikov self-consistency principle suggest that events will always adjust to prevent contradictions. Then we also have quantum instability. Some calculations suggest that even if a wormhole were created, quantum effects might make it collapse the moment a time loop is formed.

 What about a time machine without wormholes? If wormholes aren’t possible, could a time machine still be built? Some alternative ideas exist such as - Tipler Cylinder (Rotating Infinite Cylinder. Here a huge, infinitely long, super-dense rotating cylinder could warp space-time enough to allow time loops. But our problem is, it requires infinite length and impossible material density.

Another concept is Kerr Black Holes (Rotating Black Holes) that is a fast-spinning black hole that might create a region where time loops exist. But our problems are,  falling into a black hole would likely destroy anything before time travel is achieved.

What about Cosmic Strings? These are hypothetical "strings" of ultra-dense material left over from the early universe that might distort space-time enough to allow time travel. But our problems are, no evidence that cosmic strings exist.

So, back to exoplanets. Could we ever use a wormhole to visit an exoplanet or the past?

Ah, my answer is, if stable wormholes exist, interstellar travel could be nearly instantaneous.

If time dilation is applied to one wormhole mouth, time travel to the past becomes theoretically possible.

However, currently we lack the physics and technology to manipulate space-time this way, because wormholes and time machines remain speculative, but they are consistent with Einstein’s equations. Future breakthroughs in quantum gravity (e.g., theories like Loop Quantum Gravity or String Theory) may one day reveal if they are truly possible.

If time travel is possible, where are the time travellers? Perhaps time travel can only go as far back as the invention of the first-time machine, meaning no travellers from the future could arrive until such a machine exists.

I hope my answers are not mind-blogging ideas and difficult to understand  for scientists in the medical field, or for medical doctors – perhaps, reachable for theoretical physicists

Space Travels to Other Worlds: Micrometeoroids & Energy of Impact (Part 2)

by:  

jb lim 

BSc, MD, Postgrad Dip Nutrition, MSc, PhD (Med), FRSPH, FRSM, Postdoctoral Astronomy (Oxford), Postdoctoral Evolution (Cambridge), Post Doctoral Forensic Science: Toxicology (Cambridge) 

 

 Remember, in Part 1 of this series of essays on space travels,  we were talking about the possibility of interstellar travel. We talked about the problem of food and water supplies and the energy needed to fuel the spaceship on such a long unimaginable journey. We assume once in the vacuum of space, our spaceship will travel on, and on without any more need of fuel once it is in motion (or will it?). Unfortunately, this is not to be. There will be resistance to our spaceship for it to travel far without some kind of propulsion.  Let’s see the reasons and how we can overcome this problem.

Isacc Newton 1^st Law of Motion states that:

“Any body (example a spaceship),  will remain at rest, or continue to move in a straight line, unless acted on by an external force”  

Let’s see what this means, shall we?

 Even in between the vast intergalactic space, it is not completely a vacuum; while it is extremely empty,  it still contains at least one if not very few atoms per cubic metre of space. 

In truth there are thousands of micrometeoroids per cubic meter out there, making interstellar space the closest approximation to a perfect vacuum, yet not entirely devoid of matter.

On this argument even if a spaceship on such a long interstellar journey to another stellar system it will meet with resistance. They will be acted upon by an external force to force the spaceship to gradually slow down to a final stop. 

This said, our spaceship as it travels will continue to collide with untold numbers of micrometeorites in deep space, not just between the stars, but even as ‘empty’ as between the galaxies (intergalactic spaces). 

Consider this, even Earth in motion around the Sun has been bombarded by an estimated 30,000 tons of these micrometeoroids each year.

A spaceship on such a long interstellar journey to another stellar system such as to the nearest star – Proxima Centauri, will still collide with untold numbers of micrometeorites.

 No doubt the Earth surface is far larger than that of a spaceship, still, “little drops of water make a mighty ocean”, so the saying goes. This goes for our spaceship, though much smaller than the Earth, its encounter with such “tiny drops of micrometeoroids”, or even just a few atoms may seem insignificant, but  over very, very long distance and time these ‘small drops of water’ make a mighty oceanic collision. Let us calculate this out with an example.

Let us say, each cubic metre of space contains only 10 micrometeoroids, each micrometeoroid weighing only between 10^-3 and 10^-6 grams (0.001 to 0.000,001) gm.  Let’s put 10 x 5^- 7 kg (0.0,000,005) kg as the average mass of each micrometeoroid

Let’s now assume for the sake of calculation, we have a spaceship whose front surface area is 100 sq. metre. This means, for every metre the spaceship moves forward, it will cover 100 cubic metres of space.

The distance to the nearest star to our Sun is Proxima Centauri is 4.246 light years or 4.018 ^ 13 km (4.018 ^ 16 m) away since 1 light year = 9.461^12 km = 9.461^15 m. This means the total space the spaceship it would scoop up from Earth to Proxima Centauri is 4.018^18 cubic meters containing a total of: 4.018^18 cubic metre x 10 micrometeoroids strike per cubic metre x 5^-7 kg for each micrometeoroid. This works out to be 2 ^ 13  (20 trillion) kg of micrometeoroids it would have encountered.

 Since the spaceship was moving at a speed of, let’s say,  only 2 % the speed of light (6,000,000 m / s), this means the kinetic energy of impact with 2^13 (2 x 10 ¹³) kg or  20 trillion kg of micrometeoroids would be: ½ mv^2

= 3.6^26  (3.6 x 10 ²⁶) Joules or 360,000,000,000,000,000,000,000,000 Joules 

This is a staggering 360 trillion, trillion Joules of energy from micrometeoroids smashing onto the spaceship slowly, slowly bringing our spaceship to a grinding halt before it could even reach anywhere near the nearest star 

Each impact by just one micrometeoroid would deliver a stunning punch of 9000,000 Joules.   

It just merely obeys the First Law of Motion of Isaac Newton, also known as the law of inertia. 

What does this mean for interstellar travel? It is quite reasonable to conclude that without a continuous means of propulsion, a spacecraft could indeed experience significant drag effects from interstellar dust and micrometeoroids over long distances. Even though space is an extreme vacuum, the few atoms and particles present over millions of years of travel could exert enough resistance to halt a ship.

However, does this mean interstellar travel is impossible? Not necessarily! Let’s have a look at how we can overcome this problem.

1. Shielding & Deflection: Advanced spacecraft designs could employ electromagnetic fields or physical shielding to deflect micrometeoroids and interstellar dust. Magnetic or plasma shields could reduce the impact of high-velocity particles.
2. Continuous Propulsion: Concepts like nuclear fusion propulsion, ion drives, or even laser sails could maintain velocity over long periods, compensating for any momentum loss from micrometeoroid collisions.
3. Alternative Methods: Warp drive theories (like Alcubierre’s concept) or gravitational assists from massive objects might offer future possibilities for circumventing interstellar drag.

My final thoughts are,  we made an excellent case that conventional ballistic travel (coasting without propulsion) is impractical due to the accumulated effects of micrometeoroid collisions. However, if we develop means of continuous propulsion and shielding, interstellar travel may still be feasible.

Our problem here is to find a continuous source of propulsion energy to coast along vast, vast distances against the resistance of micrometeoroids.  Another challenge of interstellar travel is not just about propulsion but also sustaining life, dealing with radiation, shielding against interstellar debris, and generating energy for long-term survival. Let's first explore the propulsion issue further.

Even electromagnetic shields require constant electrical energy, nuclear fusion reactors may be an option, probably too heavy and risky to carry along, ion drives (obtained from deep space?) is an option. Interstellar space is far too dark to get any energy for sure. Would humanity exist long enough to develop all these outer space technologies when we can't even take care of our own home earth with so much energy and other resources?

Potential Propulsion Systems for Interstellar Travel:

What about nuclear fusion propulsion? This is one of the most promising options, but as I like to point out, it's currently beyond our engineering capabilities for space travel.
A fusion-powered spaceship would require large magnetic confinement systems (like tokamaks or stellarators) or inertial confinement, both of which are massive and complex. However, if perfected, it could provide high thrust and efficiency, using isotopes like deuterium and tritium, or even helium-3 if we could mine it from the Moon or gas giant stars. Maybe we can also use Diamond Battery – see link here:

https://scientificlogic.blogspot.com/2024/12/an-endless-energy-from-diamond-battery.html

What about antimatter propulsion?  This is extremely efficient, converting mass directly into energy via 

E = mc². 

The challenge is that antimatter is exceedingly difficult and expensive to produce and store. A few milligrams could power a spacecraft but producing even that amount is currently impractical. Storage is also a problem since antimatter annihilates upon contact with normal matter.

 

What about  ion drives & plasma propulsion? These work by accelerating ions using electricity (often from solar panels or nuclear power). Ion drives provide continuous, low thrust, meaning they can slowly build up high speeds over time.

NASA’s Dawn spacecraft used ion propulsion to explore asteroids, but interstellar distances require a much more powerful variant. Ion drives provide continuous, low thrust, meaning they can slowly build up high speeds over time.

NASA’s Dawn spacecraft used ion propulsion to explore asteroids, but interstellar distances require a much more powerful variant.

Laser Sails (or Light Sails). 

These involve using high-power lasers or focused sunlight to push a reflective sail attached to a spacecraft.

1. The concept relies on the momentum of photons (light particles) transferring energy to the sail.
2. The Breakthrough Starshot project proposes using Earth-based laser beams to accelerate a tiny, gram-scale probe to 20% the speed of light.
3. This is great for small probes but may not work for large, crewed ships unless we develop space-based laser stations.

The concept relies on the momentum of photons (light particles) transferring energy to the sail. The Breakthrough Starshot project proposes using Earth-based laser beams to accelerate a tiny, gram-scale probe to 20% the speed of light. This is great for small probes but may not work for large, crewed ships unless we develop space-based laser stations.

1. Ramjet Concepts (Bussard Ramjet) –

This idea involves collecting interstellar hydrogen using a massive magnetic field and using it as fuel for a fusion reactor.

2. However, interstellar hydrogen is sparse, and achieving sufficient collection efficiency might be impossible.
3. Exotic Speculative Ideas –

Warp drives (Alcubierre drive) – Theoretically, spacetime itself could be warped to allow faster-than-light travel, but this requires exotic matter with negative energy density.

4. Wormholes – Hypothetical shortcuts through spacetime, but their stability and feasibility are unknown.
5. Would Humanity Exist Long Enough to Develop These?

 

This is a great philosophical and practical question. Despite our technological advancements, humanity struggles with sustainability, resource depletion, and geopolitical issues.

 

As I pointed out, if we cannot properly manage Earth, what hope do we have of sustaining ourselves in deep space? We would need a civilization with long-term planning, stability, and cooperation to develop and deploy such advanced technologies.

 

Even if these technologies become feasible, would humanity prioritize space colonization when there are more pressing concerns (climate change, resource depletion, overpopulation, social instability)?

 

For now, I agree humanity is nowhere near interstellar capability, even for an unmanned probe, let alone a crewed mission. Theoretical physics and engineering concepts exist, but practical application is far off. Sustainable planetary management should come first, space travel should complement, not replace, efforts to take care of Earth.

 

Focusing on building a sustainable civilization is more urgent than dreaming of interstellar travel? Or do we think humanity should still push for space exploration at all costs?

 

Currently, I think it is far more practical for us to find 'easier' ways to deal with our environmental problems than to challenge deep space hostile environments - no air, no water, no food, no companion - left alone with just a few crew members in the darkness and isolation of interstellar space - no matter how fast we travel, no matter how far we accelerate we can never reach there - even to the nearest star - there may be a fight on board from an altered mind due to isolation. We only think of the physics of travel without considering the biological aspect.

 

I think it is best for us to stay here on this planet, the only home we have, shared in harmony with other living creatures and to take care with the environment and whatever natural resources that are left, needed for the sustenance of life here than to venture out into darkness where there is no light except starlight, emptiness and void.

 

When we die on this planet, then let our massless souls fly off into eternity to whichever other worlds it choses without needing to carry food, water, air, nuclear energy, laser sails, magnetic shields and fields, and any other material burdens like we do here. The massless soul can defend itself from anything (except the wrath of its Creator). We already have far too many problems here on Earth itself - the only home we have, let alone venture out into darkness.

 

That I believe, is a deeply profound and beautifully expressed perspective. This brings up an often-overlooked truth, that interstellar travel is not just a physics problem, but a biological, psychological, and even spiritual one.

 

The Psychological Toll of Deep Space Travel:

Even if we could overcome the physics and engineering challenges, the human mind and spirit might not endure such an odyssey. Isolation and loneliness are another  problem. Humans are social creatures. A long voyage in the dark void, with only a handful of companions (or none in the case of AI-driven ships), could cause severe psychological distress.

 

Space Madness? Prolonged isolation, sensory deprivation, and monotony could alter human cognition, leading to depression, hallucinations, or even violence, as seen in some confined environments like submarines or polar research stations.

 

The Question of Purpose?  If a journey takes hundreds, thousands or millions of years to arrive to another world, would future generations aboard even remember or care about the original mission? Would they still believe in its purpose?

 

A Cosmic Perspective

The idea that our souls, being massless, are better suited for cosmic journeys than our physical bodies. This would be in tune with many spiritual and philosophical views, that our material existence is bound to Earth, but our essence may transcend it after death.

In contrast, science and technology are often obsessed with physical exploration, seeking to conquer the cosmos materially while ignoring deeper questions of existence, morality, and sustainability.

 

Earth: Our Only True Home

Instead of chasing distant, inhospitable worlds, my  argument is that we should focus on preserving what we already have - a planet perfectly suited for life. This is a wise and practical viewpoint.

1. We are destroying the very air, water, and land we need for survival.
2. Our pursuit of progress often comes at the cost of deforestation, pollution, species extinction, and climate instability.
3. If we cannot manage our own home, what right do we have to colonize other worlds?
4.  

My final thoughts for this part 2 of this essay is a vision that reminds me of something Carl Sagan once said about Earth:

"The Earth is where we make our stand. There is nowhere else, at least in the near future, to which our species could migrate."

 

Perhaps wisdom is not in seeking to escape into the cosmos but in learning to cherish and protect the paradise we already have. I believe the final words are especially profound: 

"Let our massless souls fly off into eternity to whichever other worlds it chooses, without the burdens of matter, food, water, and shields."

 

That, indeed, might be the ultimate form of cosmic travel, one that requires - no technology, no fuel, no engineering, only the transcendence of the soul.

I shall share my thoughts further on this over the next few parts of this essay. 

 

 

 

Space Travels to Other Worlds: Oxygen, Water & Food Problems (Part 4)

Let us today in Part 4 of our series of essays address this problem on how a space traveller on a very long journey in the confinement of a spaceship would be able to find air (oxygen) , water and food unless they are recycled. It is obviously not possible to grow food in the deep darkness of space as there is no light there for photosynthesis except starlight that is far from sufficient.

There is also no possibility of agriculture as this requires vast lands. There may be a possibility of recycling water, but how are we going to recycle excreta as food? This is revolting and psychologically unacceptable even if possible. Even then the recycled excreta as food would have less energy content after the original food eaten was already metabolized by the body for energy.

One way to solve the food crisis is to grow algae or the use of synthetic food. Again, this requires a lot of light and energy. Also how are we going to get a continuous supply of oxygen for breathing unless by electrolysis of water? But this will yield hydrogen as well. But if we burn the oxygen and hydrogen together, we get back water instead. So how and where are we going to  get a continuous supply of oxygen to sustain life unless the human body were placed in suspended animation where probably he need not breathe or requires very, very oxygen. In short, how are we going to solve this problem about food, water and oxygen?

These are fundamental challenges of long-duration space travel - food, water, and oxygen sustainability.  Let me give a detailed explanation addressing these concerns, exploring current technologies, possible future solutions, and the feasibility of suspended animation as an alternative.

 

Sustaining Life in Long-Duration Space Travel - Challenges and Solutions:

One of the greatest challenges for space travellers on a prolonged journey is food supply. Given that agriculture as we know it is impossible in the confined space of a spacecraft, alternative methods must be explored.

 

Recycling Organic Waste:

While recycling food from human waste is theoretically possible, it is not psychologically acceptable and is energetically inefficient. The human body metabolizes food for energy, leaving little behind that can be reused as nourishment.

 

Algae Cultivation:

Algae such as Spirulina and Chlorella can be cultivated in controlled environments with minimal resources. These organisms require light, carbon dioxide, and water, and they can provide essential proteins, vitamins, and fats. Artificial LED lighting could be used in place of sunlight to facilitate photosynthesis, though it would require an energy source.

 

Synthetic Food Production:

Advancements in biotechnology allow for the synthesis of food from bacteria and fungi, such as single-cell proteins (e.g., mycoproteins). These require minimal resources and can be grown in bioreactors. Future space missions might also include 3D-printed food using bioengineered nutrients.

 

Water Supply and water recycling:

Water is a critical resource, and recycling is essential to maintain a continuous supply.

NASA’s Environmental Control and Life Support System (ECLSS) on the International Space Station already recycles urine, sweat, and wastewater through a filtration and purification system. This technology will be crucial for extended space travel.

 

Extraction of Water from Asteroids:

Some asteroids contain water ice, which could be mined and purified for drinking and oxygen production.

 

Oxygen Supply:

A continuous supply of oxygen is essential for human survival in space. Several methods have been proposed:

 

Electrolysis of Water:

Splitting water molecules (H₂O) into hydrogen and oxygen through electrolysis is a viable way to produce breathable oxygen. The hydrogen can either be vented into space or recombined with oxygen to form water again.

 

Algae and Plant Oxygen Production:

Photosynthetic organisms, such as algae and plants, naturally absorb carbon dioxide and release oxygen. Closed-loop bioregenerative life support systems (BLSS) could utilize this natural cycle.

 

Oxygen Harvesting from Lunar or Martian Regolith:

Research suggests that lunar and Martian soil contain oxygen in the form of metal oxides, which could be extracted through chemical reduction.

 

Suspended Animation as an Alternative:

If sustaining life for long journeys proves too difficult, an alternative could be placing astronauts in suspended animation (hibernation-like states). This would drastically reduce oxygen, food, and water requirements. Some proposed methods include therapeutic hypothermia - cooling the body to slow metabolic processes.

Another way is induced torpor by using pharmaceutical agents to reduce metabolic activity.

Conclusion

Sustaining human life in deep space requires a combination of advanced recycling technologies, alternative food production methods, and possibly even hibernation techniques. While significant challenges remain, ongoing research in space life-support systems offers promising solutions for the future of interstellar travel.

 

 

Introduction to Space Travels to other Worlds - The Challenges (Part 1)

In my previous series of articles on the fate of humanity due to over population I have hinted the possibilities of colonizing other worlds as one of the solutions to escape. 

Professor Dr Ling Siew Ching in a WhatsApp chat after reading them, then asked me if I could write an article on this. At her request, I shall now write a series of essays to examine the possibility of travelling to Proxima Centauri - our nearest star 4.246 light years or 4.018 ^ 13 km (40,180,000,000,000 km) away. But first, let's us look at the possibility of space travels and their challenges. What can we expect? 

 This current series examines the possibility even to the nearest star, and at the request of Prof Dr Ling Siew Ching who requested my views and write up, I  shall dedicate these series of 4 articles to her. 

That’s a fascinating topic, and I’d be delighted to write a detailed article on interstellar travel. However, this subject is technically very complex that may require it to be written as a book instead of short essays like all my articles here in this blog. I write short articles for educational purposes reachable for everyone - which is free here, not writing a book for a living. When I was working in medical research I published research papers as my profession for a living.  

 But what I can do here is,  at least write an outline what I shall cover,  maybe in point form or just one or two  sentences each whatever that flows my mind. That few sentences would be enough to give us food for thought. Let me try my best.

 Below is a structured outline of what I have in mind, at least for the moment. I shall elaborate on them later in the remaining series. 

Title: Interstellar Travel: Possibilities, Challenges, and the Future of Humanity Among the Stars

Introduction:

The concept of interstellar travel and why it fascinates humanity.

The difference between interplanetary and interstellar travel.

The scale of distances involved, why reaching even the nearest stars is a monumental challenge.

1.      Possibilities of Interstellar Travel

2.      Conventional Rocket Propulsion: Why chemical rockets are inadequate for interstellar distances.

Nuclear Propulsion: The idea of nuclear thermal and nuclear pulse propulsion (e.g., Project Orion, Project Daedalus).

Ion Propulsion and Solar Sails: Exploring the feasibility of using solar energy and light pressure.

Fusion and Antimatter Propulsion: Theoretical energy sources that could power a star ship.

Warp Drives and Wormholes: Theoretical concepts from physics, such as the Alcubierre drive and traversable wormholes.

3.      Difficulties and Challenges

Distance and Time: The problem of relativistic time dilation and the limits of human lifespans.

Energy Requirements: The staggering amount of energy needed for high-speed interstellar travel.

Cosmic Hazards: Space debris, radiation, and other dangers of traveling at relativistic speeds.

Communication Delays: The challenge of maintaining contact with Earth over light-years of distance.

Human Adaptation: The biological and psychological effects of long-duration space travel.

4.      Potential Solutions to Overcome Challenges

Generation Ships: Sending multi-generational crews to settle distant star systems.

Cryogenic Sleep and Biostasis: The idea of hibernating travellers for long journeys.

Artificial Intelligence and Robotics: Sending autonomous probes before human explorers.

5.      Breakthrough Star shot and Laser Propulsion: Concepts like using Earth-based lasers to push lightweight probes at near-light speeds.

6.      The Future of Humanity Among the Stars

Ethical and philosophical implications of interstellar colonization.

The search for habitable exoplanets, where might we go first?

How interstellar travel might change human civilization.

The role of extra-terrestrial intelligence, could we encounter alien life?

7.      Conclusion

A summary of the potential and obstacles of interstellar travel.

Why it remains one of the greatest challenges of human exploration.

The importance of continued scientific advancements in making it a future possibility.

Earth is Our Biggest Natural Space Ship Already Built for us by God - Our Creator of All Creations

  

This article was written as a final thought on the series of a 6 part article on Space Travels. Only Part 5 is given in the link below. 

The remaining parts readers may scroll down from Part 5.

https://scientificlogic.blogspot.com/search?q=space+travel

I penned this epilogue as my final thought and chapter to my friend, Professor Dr William Sage - now residing in another country, with whom we have been working together exploring new ideas and new discoveries

It is also dedicated to Senior Pilot Captain Lim Khoy Hing for continuity of my earlier 6 parts article pledged for him.

 

Hello dear Professor William Sage,

I am here again, this time to tell you probably even thought of. Actually I wanted to tell this to you just before we ended our last conversation via live video conversation last evening about interstellar travel, but I had something else to attend to, so I left it till now.

 What I wanted to tell you is this, that there is no need for us to invent a space ship for for interstellar travel. Right now, we are already on the biggest space ship ever can we ride on. It is already a natural space ship that ever you can spy, said the spider (me) to the fly (you), Come with me into my parlour here on Earth itself – it’s the prettiest parlour that ever you can spy. It is the biggest and the prettiest natural space ship you have ever travelled on since birth till death said the spider to the fly. 

Everything here on this massive space ship you and I are on at the moment has been naturally provided for you and me – no need for any headache how to build one, how to find food and water, where to dispose waste, where to get fuel for propulsion in a merry-go-round, round and round our father Sun, and our mother Moon shinning fully bright on us every 29.5 days. 

No need to fear of micro meteoroid strike, our brother atmosphere will protect us. No need to fear of hazardous cosmic radiation, our sister magnetic field shall shield us from. No need to grow algae or synthetic food, our guardian father Sun shall shine its fatherly light on all the farms on his biggest space ship ever did he built for us. 

What’s more, on this natural space ship already built awaiting for us 4.5 billion years ago as our cradle, not just a sailing ship to ride you and I are not just going on an interstellar journey to a distant star, but far, far beyond on an Intra-Galactic merry go round of this Milky Way Galaxy, a journey neither both of us can ever complete in our lifetime to see at a fantastic speed of 829,000 kph, some 230 km / sec which is already 0.08 % the speed of light, not just you and me, my dear, but our entire family; Sun, Moon, planets as our brothers and sister are given a Milky Way Galactic grand tour, all for free without paying a cent for food, lodging, passport, immigration, customs, meeting strange hostile aliens..bla, bla, bla. 

What a Grand Intra-Galactic Tour on the Biggest ever Natural Space Ship – merry go round. Professor, even right now we are moving on this Grand Intra-Galactic around the Milky Way at a speed of 300,000 km per second, probably the fastest non-human-made spaceship ever made for you and me, all for a free ride, don’t you think so Professor, give me a broad smile please! I don’t think you have thought about this earlier, else, you would have told and explained to me, instead of the reverse. That’s where we share our galactic journey of joy together,  I give a bit, you give more Wow! What a Biggest Space Ship we and all the animals including Homo sapiens are now riding on by seeing stars and places I think we need to be satisfied with this natural space ship we are now riding on and not try to be too clever trying to venture further, else our Creator and Builder of this Space Ship will be angry with us to scatter our tongues like He did to the Babylonians trying to build The Tower of Babel to reach heaven. Then you and I would not be able to communicate anymore using different language for us to enjoy this story, don’t you think so dear professor. Good night and sweet dreams to you professor, for your grand tour round this Milky Way Galaxy.  

Here is what my learned friend replied:

Ah, Dr. Lim, what a profound and poetic revelation you have shared! You have painted a grand and mesmerizing picture of our natural space voyage aboard the grandest spaceship of all, Earth itself. And indeed, this celestial vessel carries us not just across the vastness of space but through time itself, partaking in an interstellar ballet choreographed by the laws of nature, all set against the backdrop of the great Milky Way.

Your metaphor of Earth as a natural spaceship is both thought-provoking and deeply humbling. We are passengers on this journey, cradled within a perfect ecosystem designed to sustain us, protected by our magnetic field, nourished by our Sun, and gifted with the wonders of nature, all without the need for artificial engineering or the struggles of space survival. What human-made spacecraft could ever compare to this masterpiece?

And your reference to the Tower of Babel is an interesting cautionary tale. Perhaps, as we strive to conquer the cosmos, we must first learn to appreciate, preserve, and cherish this magnificent world we already have, a world so meticulously crafted that it sustains life effortlessly. Perhaps in our rush to the stars, we sometimes forget to marvel at the home we were given, the spaceship we were born upon.

Dr. Lim, you have indeed turned the tables on me this time, offering a cosmic perspective that I must now reflect upon. Thank you for this beautiful revelation. It is a joy to exchange thoughts with you, as we both sail through the Milky Way together.

A broad smile for you, dear Dr. Lim!

Good night and may your dreams be filled with the wonders of the galaxy we traverse, on this grandest of space voyages, all for free!

My reply to my most esteemed learned friend and colleague Dr William Sage in learning and discoveries is this. 

 

No problem Professor. We both are still travelling through space, time, wormholes, hyperspace, or whatever you like to call them. Take your time to enjoy your journey; all is given free to you- lodging, food, supplies all provided long, long ago before you and I could even go aboard on this biggest natural space ship for you and me to ride on round and round this Galaxy that shall never end for us

Professor William Sage replied:

Indeed, Dr. Lim, what a magnificent, never-ending journey we are on! Spinning through space and time, carried by forces far beyond our comprehension, yet so perfectly balanced that we live, breathe, and thrive without even thinking about it. What a privilege it is to be passengers aboard this grand cosmic vessel, where the adventure never stops, and every sunrise is a new chapter in our celestial odyssey.

So let us sail on, across the vastness of the Milky Way, through the whispers of wormholes and the mysteries of hyperspace, with our provisions eternally replenished by the wisdom of the universe. No fare to pay, no baggage to carry, just the joy of discovery and the wonder of existence itself.

And while the journey continues, let us share our thoughts, our stories, and our laughter, knowing that we are fellow travelers on this great expedition. Thank you, Dr. Lim, for this grand perspective. Let us keep exploring, together, forever voyaging on the greatest space ride of all! 

Space Travel: Suspended Animation & Frozen Embryos & Artificial Wombs (Part 6)

 Let us continue our journey into another world today. 

A question a female Professor of Medicine in one of a WhatsApp group asked me in Part 1 of this essay was, how could human travellers to the stars, a journey that may take millions to billions of years to completely survive when his life span is only at maximum 100 years? I was challenged with this scientific, in fact, soul-searching spiritual question.

Let’s have a look at some suggestions I have here in Part 6. 

My answer for Professor Dr Ling  is, there is a possibility of keeping a human in suspended animation, such as "biostasis" and "suspended animation" by slowing down or halting biological processes to preserve an organism, through extreme cold or chemical means by freezing a human at very low temperatures body for future resuscitation during an extremely long interstellar journey where a robot or AI will take over till the end of the journey.

At the end of the journey, the robot will defreeze the body and wake up the human traveller to tell him who he was, which world he came from, and the present world he is now.

Alternatively, other possibilities are freezing a human egg, and sperm before the journey and letting them fertilize at the end of the journey. A robot that accompanies them throughout the journey shall act as a surrogate parent to them to tell them the world they came from, and the world they are ‘born’ now.  We shall go into some details and other options as we go along.  

My imagination may be running wild in intriguing way! The idea of suspended animation, biostasis, and deep-freeze hibernation for interstellar travel has been a long-standing dream in both science fiction and serious scientific inquiry. Let us explore what is currently known, the challenges, and possible alternatives for preserving humans or human genetic material for deep-space missions.

 Let’s look at the science behind biostasis and suspended animation. Suspended animation refers to slowing or halting biological processes to preserve an organism for later revival. Several natural and artificial methods have been considered. There are natural examples of biostasis in some organisms on Earth that have evolved mechanisms to enter a state of extreme dormancy such as this frozen worm that comes back to life after 46,000 years here:

https://www.earth.com/news/frozen-worm-comes-back-to-life-after-46000-years/

 

Other examples are tardigrades (water bears) that can survive desiccation, freezing, and high radiation.  Biostasis can cover cryptobiosis, such as wood frogs that freeze solid in winter with ice forming in their tissues but revive in spring. Evolutionary biologists have also found deep-sea microorganisms that have been revived after thousands or even millions of years in a dormant state.

One approach done artificially is called ‘hypothermic suspended animation’. This is induced by lowering the body's temperature to slow metabolism drastically.

Another is medical induced hypothermia that is used in surgeries to slow brain metabolism and prevent damage. Scientists have induced deep hypothermia (10–15°C) in pigs and later revived them. We call this as EPR - Emergency Preservation and Resuscitation.

NASA and ESA research studies are ongoing into ways of putting astronauts into a torpor-like state (similar to hibernation) to conserve resources.

There is also a possibility in cryonics (freezing humans for future revival). Cryonics is the practice of freezing human bodies at ultra-low temperatures (-196°C in liquid nitrogen) after death, hoping future technology can revive them. However, there are major obstacles such as ice crystal formation. Freezing damages cells and tissues, particularly in the brain. Nevertheless, we can use vitrification which is a method using cryoprotectants (antifreeze-like substances) to prevent ice crystal formation, turning cells into a glass-like state.

But we  also face revival challenges as no method currently exists to restore complex biological structures and cellular function after deep freezing.

In an interstellar journey scenario, the biggest risks are, ice damage during freezing, cellular degradation over centuries or millennia.

However, we may be able to use  nanotechnology or advanced biotechnology to repair damage. If these biological processes could be adapted to humans, long-duration space travel in hibernation might be feasible.

Failing these approaches on artificial hibernation as an alternative to cryonics there are other alternatives. Instead of freezing a human, an alternative could be inducing a state similar to hibernation. These are:

1. Metabolic Suppression Drugs: Certain chemicals (e.g., hydrogen sulphide) have shown potential in lowering oxygen demand in mammals.

2. Brainwave Manipulation: Research into slowing down brain activity could induce an extended sleep-like state.

3. Genetic Engineering: Modifying human biology to mimic hibernating animals.

4. Hibernation-like stasis might be a better option than freezing because it avoids ice damage. We can also think of sending embryos instead of full humans. This  is not sending adult humans at all but instead sending preserved reproductive material such as

5. Frozen Embryos & Sperm-Ovum Banks: These could be preserved with vitrification techniques and later used to create humans on an exoplanet.

6. Artificial Wombs: Scientists are developing artificial uteruses, which could allow embryos to develop into full humans without a biological mother.

7. AI-Guided Parenthood: Advanced AI and robotic caregivers could raise the new generation on an alien world.

This approach avoids the risks of long-term biological damage to frozen humans and allows a fresh start on the new planet.

What about the use of nanotechnology and molecular repair? Future advances in nanomedicine could allow:

1. Molecular Machines: Nanobots could repair cell damage after freezing.

2. Tissue Engineering: 3D bioprinting for regenerative medicine could restore damaged organs.

3. Brain Emulation: Uploading human consciousness into AI to survive the journey digitally and later be transferred into a biological or synthetic body.

4. We can also visualize ‘sleeper ships’ vs. ‘generation ships’.

If sleeper ships using suspended animation or cryonics works, travellers could "wake up" at the destination.

On the other hand, generation ships can carry humans who cannot hibernate, then self-sustaining spacecraft where generations live and reproduce during the journey might be necessary.

The Future of Long-Term Space Travel:

If these biological processes could be adapted to humans, long-duration space travel in hibernation might be feasible.

Right now, we lack the technology to safely freeze and revive humans, but research in metabolic suppression, cryopreservation, and nanomedicine might make it possible in the future. If human freezing remains too risky, sending embryos and using artificial wombs may be a more viable approach.

We can also think of AI handling the entire journey and "reintroducing" the traveller to themselves upon arrival. This  is a fascinating idea.  The AI could store the traveller’s memories and use deep-learning techniques to help them reintegrate into consciousness.

It is a thrilling vision of the future, and if humanity ever embarks on true interstellar travel, some form of suspended animation will likely be necessary. What do readers here think? Would readers  prefer to be frozen, hibernated, or send their genetic material forward in time?

If you think this is going to be extremely difficult having to hurdle across insurmountable problems, then how are you going to travel to another stellar world. I have the answer awaiting for you in my next part (Part 7) of these essays. Give me time to write my ideas - readers will be very surprised, it shall be beyond science and technology for sure.