February 21, 2021

The Limits of Science

The Limits of Science

By Darren Arndt, BSc

Copyright 2021

 

Introduction

Science is increasingly viewed by many people as being able to 
answer any and all questions about our world. It certainly has a 
strong track record of solving many mysteries of life and the 
universe over the past few centuries. However, science has 
always had its limits and that remains true of modern science 
today. 
 
Some materialist writers claim that science has explained every-
thing, or will soon explain it. “There is nothing that the scientific 
method cannot illuminate and elucidate,” said Peter Atkins in his 
book On Being.  Unfortunately, publishing something in a book 
(or on a blog!) does not make it true.

Science has always had boundaries. Some boundaries are 
temporary but others are stubbornly persistent. These limits of 
science were never discussed by any of my university professors 
but they should have been. In order to have a correct understanding 
of what science is, one must know where science ends. That is the 
purpose of this article.

I propose the limits of science can be grouped into four categories: 
technological, physical, theoretical and those of scope. I will explore 
each of these below. This is not an exhaustive list but hopefully it is 
sufficient to support my premise.

 

 1  Technological Limits of Science

 

As science has advanced over the centuries, it has become more 

and more dependent on technology. While some observations are 

possible with the naked eye, such as reading a thermometer or a 

stopwatch or the colour of a chemical byproduct, most areas of 

scientific investigation now require advanced technology to provide 

greater levels of observational precision.

 

For example, astronomy is limited by the capabilities of telescopes. 

Galileo’s primitive telescope allowed him to see the moons of Jupiter 

and the rings of Saturn. The Hubble Space Telescope can see 

galaxies 10 billion light years away or more. The next generation of 

space telescopes will exceed Hubble’s capabilities significantly.


Similarly Van Leeuwenhoek’s simple microscope progressed to 

modern scanning electron microscopes able to produce over a 

million times magnification.


Technological limits are relatively temporary. As technological 

improvements are made, the limits of science are pushed back and 

new discoveries become possible. When scientists speak about 

science explaining everything eventually, they are usually referring 

to the progress of technology to push back the boundaries of 

discovery. However, technological progress never removes those 

boundaries -- it just moves the boundaries to new positions.


Technological limits are real and are always present in science. 

They prevent scientists from answering certain questions today 

until the technology progresses. The Higgs boson was proposed in 

1964 but it could not be detected until 2012 using the latest tech-
nology at the CERN Large Hadron Collider. X-ray astronomy could 

not progress until the advent of satellites because the atmosphere 

blocks x-rays from reaching the Earth’s surface. Current technology 

always forms one very real boundary of scientific knowledge.

 

 2 Physical Limits of Science

 
Since science is the study of the physical universe, it may be 
obvious that any limits inherent in the physical universe are also 
limits of science. Technology may progress a long way but its 
progress is eventually impeded by these physical constraints.

 

For example, nothing can be cooled below absolute zero. Once all 

heat is removed so every substance becomes a solid, there is no 

more heat that can be removed. No scientific technology can break 

that physical limit. This may seem trivial as who would ever want 

something to be colder than absolute zero anyway?  


Other physical limits are not as trivial however. Spaceships can be 

designed to travel faster and faster but never faster than the speed 

of light. That limit would be very helpful to overcome for interstellar 

travel but it cannot.


In the computer world, reducing the size of electronic circuitry is 

limited by quantum tunneling. When the conducting path is about 

1 nanometer (or one billionth of a meter), the electrons can oc-

casionally move across the insulating barrier into the neighbouring 

conductor and confound the functioning of the circuit.  Circuit boards 

must stay at a large enough scale to prevent electron tunneling from 

occurring even if the technology is available to make the circuitry 

smaller.


The medical sciences are limited by death. Despite incredible 

advances in disease treatments and amazing resuscitations that can 

occur minutes after a heart stops beating, once death occurs it is 

stubbornly permanent. There is no treatment for corpses that can 

return them back to life. Two hundred years after Mary Shelley 

wrote her book Frankenstein, it remains firmly on the fiction shelf of 

the library.


The physical universe also limits us in the dimension of time. Time is 

a one way street. We cannot go back in time and undo our regrets. 

We cannot unbreak a broken egg and have it reassemble in front of 

our eyes. As Richard Feynman taught in his 1960’s lecture

The Distinction of Past and Future, “In all the laws of physics that we 

have found so far, there doesn’t seem to be any distinction between 

the past and the future.” No scientific law requires time to move 

forward and no law forbids time from moving backwards. Our 

experience however tells us time only ever moves in one direction. It 

appears to be a physical trait of our universe that science has not 

explained and cannot change.


Time is also relevant in terms of predicting the future. Some scientific 

laws are excellent at predicting the future or even going back in the 

past. Newton’s laws of gravity work very well going forward or going 

backward, as long as it is not near a massive star where the rules of 

general relativity kick in. We know the conjunction of Jupiter and 

Saturn in December 2020 was the closest those planets have been 

in our sky since 1623 because Newton’s laws can be modeled back-

wards quite accurately. We also know they won’t be that close again 

until the year 2080 because Newton’s laws can be modeled forward 

as well. It was this deterministic success of Newton’s laws that led 

French scientist Laplace to declare in 1814 that all branches of 

science would one day have this level of predictive success. 


Unfortunately it turned out Laplace was wrong. Most areas of sci-

ence have nowhere near that level of predictive ability. Weather 

forecasting is an excellent example. Meteorologists can predict the 

weather 1 or maybe 2 weeks in advance, but not much further than 

that. No one would believe a weather forecast 3 months in advance 

and certainly not a year in advance. It would be laughable to ask for 

the weather forecast for your city during the next close conjunction 

of Jupiter and Saturn in 2080!


Why are meteorological models less accurate predictors than planet-

ary orbit models? Is it because meteorologists are lacking sufficient 

technology to predict the weather?  No, there are lots of weather 

satellites, Doppler radar transmitters, automated weather stations 

and complex computer models employed to this end. Is it because 

the current theories of meteorology are lacking? No, weather pro-

cesses are quite well understood. It is simply because weather 

systems are far more complex than planetary orbits.


Meteorology is an example of a complex non-linear system. It is a 

case study for chaos theory and the Butterfly Effect. Weather is 

difficult to predict because very small perturbations in the initial 

conditions have huge effects on the outcomes in the future, such 

as a butterfly flapping its wings affecting the behaviour of a tornado 

weeks later. This is a physical characteristic of this system and it 

limits the predictive accuracy that science can achieve.


There are many other complex systems. COVID-19 has demon-

strated this clearly in 2020 as numerous infectious disease models 

have failed to accurately predict COVID-19 infection or death rates, 

nor have they accurately predicted the effects of policy mandates 

such as social distancing or face masks. Infectious diseases and 

their interactions with a population of human immune systems are 

very complex indeed. 


An example of a mechanical chaotic system is the motion of a 

double pendulum, or a pendulum with another pendulum attached to 

its end. This video shows six examples of an identical starting 

pendulum position that quickly leads to six very different behaviours. 

Predicting double pendulum motion is nearly impossible beyond a 

few seconds in the future. It is not because we lack a theory of 

pendulum motion and it’s not because we lack sufficient pendulum 

technology. It is entirely due to the complex nature of this system.


Physical limits of the universe therefore limit science’s technological 

capabilities and its predictive precision. While medical treatments, 

meteorological models and disease models are likely to improve in 

the future, they will never remove these physical limits. There is 

nothing science can do to make this complexity go away.

 

3  Theoretical Limits of Science 

Another category of scientific limitations comes from within certain 
scientific theories themselves. One of the best examples involves 
black holes from Einstein’s General Theory of Relativity. The bound-
ary where material and light cannot escape from a black hole is 
called the Schwarzschild Radius. It is tempting to consider this the 
boundary of the black hole, but it is not anything physical.  It is not 
like the surface of a planet or a star, but rather a mathematical 
boundary where the escape velocity of the black hole equals the 
speed of light. As matter outside this radius is pulled towards the 
black hole, physics can explain what is happening up until the matter 
reaches the Schwarzschild Radius. At that point, the mathematical 
formulas produce a divide-by-zero error and physics breaks down. 
We know the matter physically continues to fall into the black hole 
across this theoretical boundary but physics can no longer explain 
what is happening to it. This is a purely theoretical limit of science. 
It is not a failure of the theory nor some kind of incompleteness of 
the theory. It is simply an explanatory limitation of the theory.

 

The Big Bang Theory begins with a singularity when all the energy 

and matter of the universe is contained in a tiny region where space-

time curvature becomes infinite. It is infinitely small, infinitely dense 

and infinitely hot. In other words, the mathematical formulas meet 

another divide-by-zero barrier. Physics can explain what happens 

a tiny fraction of a second after singularity, but it cannot explain what 

happens at the Big Bang’s singularity nor can it explain what 

happened before it. This is the single biggest limitation of any branch 

of science. Despite all of its incredible successes, science cannot 

explain what happened at the absolute beginning of the universe. 

It is an impenetrable wall impeding any attempt at scientific 

investigation.


There are a couple other limitations of science that could fit in either 

the physical category or the theoretical category. Regardless of your 

preferred categorization, they are limits nonetheless.


A significant limit from quantum mechanical theory is Werner Heisen-

berg’s Uncertainty Principle. This states that there is a limit to the 

accuracy one can measure a particle’s position or momentum. The 

more accurate the measure of position is, the less accurate the 

measure of momentum must be, and vice-versa. This is often ex-

plained as an observer effect, in that by shining a photon on a small 

particle, the photon will convey energy to that particle and change its 

position and momentum in the act of measuring it. However the 

uncertainty principle is fundamentally a derivation from the wave-

particle duality of the quantum mechanical world. Because particles 

are also waves, the edges of the particles get a bit blurry and the 

motion of the particles becomes wave-like, making the specific loc-

ation and motion of the particle difficult to measure with precision. 

Regardless of which explanation one prefers, this is a very real 

limitation of our ability to measure the quantum world.


Another limit from the Big Bang Theory is the edge of the universe 

and the beginning of time. Because light travels at a fixed speed, 

when we look at objects in the sky we are seeing them as they 

appeared when the light left them. We see the moon as it was 1.2 

seconds ago, the sun as it was 8.3 minutes ago, the nearest star 

Proxima Centauri as it was 4.2 years ago, and the nearest spiral 

galaxy Andromeda as it was 2.5 million years ago. Therefore tele-

scopes should not be able to see anything further back than the Big 

Bang, about 13.8 billion years ago. Our current telescope technology 

is getting close to that limit and the next generation of space tele-

scopes should provide the ability to conclusively confirm or disprove 

this time and distance limit. It is interesting to note that the Steady 

State Theory which was more popular among cosmologists until the 

mid-20th century provides for no such beginning or edge of the 

universe. Therefore this is a theoretical limit which may also be a 

physical limit as long as the Big Bang theory continues to prove 

correct.


Lastly, theoretical limits exist when observations cannot be explained 

by any existing laws of science. Dark matter and dark energy are the 

best current examples of this.


Dark matter was first postulated to explain the observed rotation of 

galaxies. There must be more mass in the galaxies than what is 

visible in order to match the predictions of the current law of gravity, 

which is Einstein’s General Theory of Relativity. This extra matter 

must be both massive and invisible to us, meaning it does not react 

to light. There is no such substance currently known to science. It 

may be explained in the future by the discovery of a new subatomic 

particle or a change to the theory of gravity such as Modified 

Newtonian Dynamics, but the answer is currently unknown.


Similarly, dark energy was postulated to explain the observations 

that galaxies are accelerating away from us. There is no known 

repulsive force that could act at such large distances. It is effectively 

behaving like anti-gravity but anti-gravity only exists in science 

fiction stories. It resembles Einstein’s cosmological constant which 

he later discarded. Dark energy could mean our understanding of 

gravity is incomplete or the Big Bang theory is incomplete or there 

is another undiscovered subatomic particle out there. It is currently 

a scientific mystery. 

 4 Limits of Scope

Despite Peter Atkins’ belief that “there is nothing that the scientific 

method cannot illuminate and elucidate,” the scientific method 

contradicts him quite clearly. Science is limited to observable 

physical events. Anything that is not physical and not observable is 

not within scope of the scientific method. The early scientists 

understood that science had clear limits in scope, unlike modern 

scientific materialists.


One area outside of the scope of science is ethics. What branch of 

science defines which human behaviours are good or bad? Which 

natural law requires scientists to be honest when reporting their 

findings in scientific journals? Biological natural selection seems to 

care only about passing one’s genes to the next generation, so if 

lying to your date results in having sex then lying must be good. 

Survival of the fittest implies the stronger can eliminate the weaker 

members of a population, a scientific principle that Hilter’s Nazis 

took to the extreme in their death camps. Great evils have been 

committed when science alone becomes the basis for morality. 

Ethics are not physical nor observable and yet they are essential 

to society, including for a well-functioning scientific community.


Another example of something non-physical is God. Since most 

concepts of God are that of a spiritual and supernatural being, then 

God must be outside the scope of science. Isaac Newton realized 

this and in his Principia Mathematica wrote, “The most beautiful 

system of the sun, planet and comets could only proceed from the 

counsel and domination of an intelligent and powerful Being.” 

Newton felt his discoveries regarding the laws of motion and gravity 

did not disprove the existence of God, but rather supported his 

existence. Newton realized that God existed outside of these 

physical laws. Similarly, Descartes felt that the natural laws of 

physics could be deduced from the characteristics of the God who 

created those laws. He saw the law of conservation of momentum as 

being consistent with God’s unchanging nature. Scientific discovery 

has a clear boundary that limits it to the study of the physical world. 

Anything metaphysical is out of scope. One can choose to believe or 

not believe in God, but science cannot directly inform those beliefs.


There are many other things outside the scope of science such as 

beauty, hope, purpose in life, the afterlife, and on and on. Because 

these things are outside the scope of science does not make them 

unimportant. In fact they may be more important than many of the 

topics science can address. As Einstein famously said, “Not every-

thing that counts can be counted, and not everything that can be 

counted counts.”

Conclusion

Science has always had boundaries and will always have them. Two 

types of boundaries are relatively temporary: technological and 

theoretical boundaries will eventually be pushed back. Two types of 

boundaries are permanent: physical and scope boundaries are not 

going anywhere.


The temporary boundaries are called the frontiers of science. It is 

those areas of science where unanswered questions are being 

actively investigated and new technologies and theories are being

developed. It is where scientific knowledge is constantly changing, 

improving and expanding. These boundaries however never 

disappear. Their positions will change but their presence remains.


Returning to Peter Atkins’ statement that “there is nothing that the 

scientific method cannot illuminate and elucidate,” let’s test it out. 

How can the scientific method illuminate the following questions?


What will the weather be like 5 years from today?

What career path will I find most fulfilling?

Should I steal my neighbour’s sports car and take it for a spin?

Will I go to heaven after I die? If so, what is heaven like?

Should I get high with my buddies this weekend?

What is the most beautiful symphony ever composed?

What is the purpose of my life?

Should I kill myself?


These questions range from trivial to profound to tragic. Science 

can answer none of them. 


Many scientists will offer loud and bold answers to many of these 

questions but those answers only reflect their personal beliefs, and 

personal beliefs of scientists do not equate to science.


Erwin Schroedinger, one of the fathers of quantum mechanics, 

summarized it like this:

I am very astonished that the scientific picture of the real 

world around me is deficient. It gives a lot of factual infor-

mation, puts all our experience in a magnificently 

consistent order, but it is ghastly silent about all and sundry 

that is really near to our heart, that really matters to us. It 

cannot tell us a word about red and blue, bitter and sweet, 

physical pain and physical delight; it knows nothing of 

beautiful and ugly, good or bad, God and eternity. Science 

sometimes pretends to answer questions in these domains, 

but the answers are very often so silly that we are not 

inclined to take them seriously.


Anyone who believes science can answer all of life’s questions is not 

only being naive and wishful, but to borrow Richard Dawkins’ term, 

they are the ones who are being delusional.