This is a long post, but I think it is worth it. I think I’ve untangled a lot of concepts that have become tangled in the popular science imagination and if you enjoy having your mind stretched and sorted, this post is for you. I’ll start this disentanglement process with a simple problem:
Problem: It appears that there are objects moving apart faster than the speed of light. This contradicts the idea that light travels at a maximum possible speed.
- Solution A: If space itself expands, then when we see objects moving apart at faster than the speed of light, we can call this an illusion caused by expanding space. We describe all physics with a curved, Riemannian coordinate system which changes when matter moves.
- Solution B: If space is defined by a flat, Cartesian, absolute coordinate system which does not change when matter moves, when it appears that objects exceed the speed of light, we must conclude that this is an illusion caused by light losing energy as it travels across vast distances.
Solution A is consistent with big bang, standard model cosmology in which dark matter holds galaxies together and dark energy blows everything apart.
Solution B is consistent with tired light cosmology in which dark matter and dark energy are illusions caused by wakes created behind matter that moves relative to an absolute frame of reference.
This is the simplest way to state the problem, but because so many redundant, overlapping languages and definitions have sprung up over the years, a statement of the problem that draws in all of these terms is as follows:
Does light travel to us in straight lines through the expanding, curved, Riemannian, Minkowski, de Sitter space of a big-bang, flat universe or does it travel to us along meandering rivers in the flat, jiggling space of a gravitoelectromagnetism, steady-state, Cartesian, tired-light, electric, plasma, round universe?
The answer to this question will determine whether
- galaxies never move faster than the speed of light relative to one another because once they hit the speed of light, they disappear from the perspective of the other galaxy… and when you can’t see something, it doesn’t exist.
Or
- galaxies actually move faster than the speed of light relative to one another and just because we can’t see things that are moving away from us at faster than the speed of light doesn’t mean that those things don’t exist.
Your personal preference for one of these options may depend on whether or not your mommy played peekaboo with you when you were a baby and you absolutely must choose between these languages because if you try to mix them, you will get very confused.
Either
- relative to a single point, nothing travels faster than light.
Or
- relative to two points, velocities can appear to exceed that of light.
The choice is between a relative reference frame (big bang) and an absolute reference frame (tired-light).
According to fans of Einstein and the big-bang, there is no such thing as an absolute reference frame and, if you didn’t know better, you might think that Einstein’s language is an experimentally proven fact because of Eddington’s experiment with starlight and Michelson and Morely’s experiment with an interferometer, but it is not. The language is something that Einstein postulated a priori. That is the fancy way of saying that it was an assumption. There are other ways to describe the same system with different a priori assumptions.
If instead, you ignore Einstein and insist on sticking with your intuition by talking about an absolute reference frame, you have to derive everything in a language which is inconsistent with Einstein’s. So, to avoid being a pariah, most physicists speak Einstein’s language, even though it sounds really weird from a regular person’s perspective because regular people don’t look up at the sky with tunnel vision.
Ironically, Einstein’s counterintuitive language tends to make regular people think that they aren’t smart enough to understand physics and that seems to be the language’s primary function – bedazzlement and mystification of the cosmos. To me, it looks like a BS marketing trick designed to make people think that physicists are smarter than everyone else.
Some believe that the choice between these languages is based on philosophy and aesthetics, but what does experiment tell us?
A big-bang person would tell you that tired-light is ruled out because starlight is not diffuse — it is pointlike and it would’ve been diffuse if the light’s energy had been lost through quantum scattering processes with atoms or molecules spread throughout the cosmos. This is a straw man argument because there are other mechanisms through which light could lose energy without relying on atomic scattering processes.
Michelson-Morely told us that light does not lose energy when it travels in straight lines, but the Sagnac loop told us that light does lose energy when it travels in circles. Since Eddington’s experiment tells us that gravity bends light, it seems quite clear to me that the Sagnac loop experiment implies that light should lose energy as it travels through the cosmos, yet in the big bang framework, this does not happen because in the wierd coordinate system they use, curved paths are defined to be straight because it is easier to integrate (add things up) along a straight path than along a curved one. Tricky, eh? Uneccessarily so? Definitely.
I believe that the loss of starlight’s energy as it travels along a winding, cosmic path can also be connected to the quantum uncertainty principle in which a minimum momentum change is allowed over a certain, minimum distance. Each little step corresponds to a little bit of lost energy. From this perspective, the big-bang interpretation of astronomical data is incorrect because it does not fit with what we understand about the uncertainty principle whereas a tired-light interpretation does.
I don’t understand why astronomers forgot that the weird coordinate system they were using for general relativity was just a static approximation of a dynamic system. The map is not the territory. I don’t understand why they forgot that Sagnac’s and Eddington’s experimental results suggest that starlight loses energy and follows curved paths as it travels towards us. The wavelength is not stretching out as space itself expands in a big bang universe.
Then again, scientists often underestimate the role that religion plays in their preference for a theory. Just ask Galileo if religion influences theory preference. Who could resist a poetic, big-bang narrative with a dramatic, ‘let there be light moment’? Tired light from stars that may have been burning forever sounds so… tired in comparison. Maybe tired-light just needed some more clever marketing.
This issue is quite muddled in popular discourse because the examples taught in school or in pop-science media knock tired-light down like a straw man while leaving big bang LCDM cosmology standing tall.
The story told is that steady-state or tired-light theory posits that the number of photons-per-second from each object drops in proportion to the square of the distance, while the number of objects increases with the square of the distance and since this isn’t what we see, tired-light theory must be wrong.
This is a straw man argument because, unlike big-bang theory, the beginning of time is outside of tired-light’s purview and, in any case, just because you can’t see a certain star doesn’t mean that it doesn’t exist. I can imagine a scenario in which a star is invisible because it is vibrating in a mode which is out of sync with our own.
A gradeschool teacher would explain the concept in terms of a child being pushed on a swing. If you are pushing at exactly the wrong time during every swing, there will be no energy transfer. When there is no energy transfer, you are blind to each other and it is possible for us to be blind to distant stars in this way.
A physicist who thinks in the spatial domain would explain that if the atoms in the distant star are moving back and forth at faster than the speed of light relative to us, then they will be invisible to us.
A physicist who thinks in the time domain would explain that if the atoms in the distant star are emitting light which is out of synch with the light which we emit, then our light will interfere destructively and we will be invisible to one another.
These two explanations are geometrically equivalent and they are consistent with the worldview of people like Maxwell, Bjerknes, and Hertz. They looked up at the sky and saw stars in jiggling jello. It isn’t a bad heuristic. It just went out of fashion. They wouldn’t have found the eclipticity of the cosmic microwave background strange or mysterious at all.
So far, I’ve conflated steady-state and tired light theories while contrasting them with the big bang theories. Since physics must be rigorous, it is time that I define these terms more precisely. (a) The big bang universe expands at an accelerated rate while the speed of light is constant. (b) The tired light universe expands at a constant rate while light’s speed decreases with distance between the source and the observer. (c) The steady-state universe is static while light’s speed decreases with increasing distance from us.
(a) How do we know that the universe is expanding at an accelerated rate while the speed of light is constant?
These are the assumptions behind the big-bang paradigm in which gravity is explained by the accelerated expansion of space itself. This heuristic involves masses sinking into space that grows progressively more spread out over time and it is supported by prominent pop-scientists.
The position of this LCDM cosmology paradigm in the firmament was reinforced by the 2011 Nobel prize given to American physicists Reis, Perlmutter, and Schmidt, a prize which has since been called into question by a re-analysis of the data in 2016. It appears that the Nobel Prize winners failed to take the motion of the Earth into account.
In 2017, I drew attention to this work by Sarkar and pop-scientist Sabine Hossenfelder recently made a video about the importance of Sarkar’s work.
Basically, it seems that Reis, Perlmutter, and Schmidt confused the motion of the Earth with the motion of more distant stars. When you look at more of the stars, this error becomes clear. What isn’t clear is why the community doubled down on this mistake by granting the 2019 Nobel Prize to James Peebles, a man who built his career around Big Bang cosmology.
(b) How do we know that the universe expands at a constant rate while light’s speed decreases with distance between the source and the observer?
These are the assumptions behind the tired light paradigm and the gist of the idea is that the expansion of flat space is described by gravitoelectromagnetism, Heaviside’s 1879 theory of absolute space and time which somehow got replaced by Minkowski’s curved space general relativity in 1921 when world war politics coupled with Eddington’s experiment with starlight during a solar eclipse turned Albert Einstein into the poster boy for physics.
People got all excited about the idea of bent space without understanding that just because a few effects can be described with a bent coordinate system, that doesn’t mean the coordinate system depicts reality.
This is analogous to the confusion of flat earthers who look at a picture of a round earth and say that it only looks round because of an optical illusion.
Most events are better represented by a flat coordinate system and it makes more sense to say that space is flat and bending or slowing of light is caused by how mass or charge alter the properties of space though, for example, turbulence which slows the propagation of light. In this way, the cosmos can be described with the same language that we use to describe optical systems. Mystery solved! No need for more funding. Go do something more useful.
I am fond of the tired light paradigm because it is so easy to marry it to quantum mechanics with localized vibrations of space that make things heavy in the same way that causing a pan of sand to vibrate will make the objects in the sand act heavier.
Similarly, mysterious dark energy and dark matter don’t exist in this universe because
- Dark energy is the positive deviation from what general relativity predicts for masses which are not moving.
- Dark matter is the negative deviation from what general relativity predicts for masses which are not moving.
When masses are moving relative to one another, general relativity delivers erroneous predictions of matter that doesn’t actually exist.
- Dark energy is the apparent result when masses are moving in the same direction relative to each other. (Picture the wakes of boats pushing the boats apart.)
- Dark matter is the apparent result when masses are moving in opposite directions relative to each other (as in the spiral arms of a galaxy).
(c) How do we know that the universe is static while light’s speed decreases with increasing distance from us?
These are the assumptions behind the steady-state paradigm favored by Fred Hoyle and it seems that some people have tried to rebrand his theory in the language of massive gravity. Whereas the tired light paradigm is consistent with how we describe optical systems, the steady-state paradigm is consistent with how we describe solid-state systems in equilibrium – like a room-temperature superconductor. This is sort of like tired light with more optimistic assumptions about entropy than Newton’s 2nd law suggests. The idea is that entropy is positive on some length scales and negative on other, more lively length scales. In accordance with Newton’s 1st law, energy is transferred back and forth between the two states without ever being created or destroyed. Whenever light loses energy inits direction of travel, a wave propagating in the opposite direction gains energy. An old way to express this concept is in terms of energy and exergy, but when words are lost from the lexicon, intuition may disappear as well.
(d) How do we know that all of the above are valid ways of describing the system?
You can describe a system in multiple languages and not be wrong about any of them. You choose your favorite language based on how precisely it describes a given effect.
(e) How do we know that none of the above are valid ways of describing the system?
All of the languages of physics are and will always be approximations of a system about which we will never be able to know the initial conditions and will, therefore, never be able to fully predict.
This all boils down to: is the star moving away or does it just look like it is moving away? How can you tell? Since astronomy is a descriptive science, not an experimental one, we can’t decide this based on which theory has superior predictive power. Instead, one might make this choice based on the degree of self-consistency an individual theory possesses, but I believe that the choice should be made based on how well the theory fits with other theories – a more holistic, meta measure of self-consistency.
………
People who’ve been conditioned to imagine a big bang bubble that expanded at greater than the speed of light and then popped often find it difficult to imagine anything else. Those who believe in the big bang say that there was an inflationary epoch during which particles traveled faster than light – just like the Standard Model virtual particles within collider experiments which temporarily violate conservation of energy. Then, all of a sudden, for no discernible reason, we are supposed to believe that the laws of physics suddenly changed and everything that happened since must travel at less than the speed of light. Wild story. I saw Andre Linde tell it in a SLAC conference room when I was just a child. I’ve since been amazed by how much sand castle empire building resulted from this lark. Some of those who founded the theory have since abandoned it while the man who stood by it won the 2019 Nobel Prize (James Peebles). Loyalty to the group pays off.
Perhaps big-bang believers are being such sticks in the mud because they want to protect their friends in particle physics. All it takes for tired-light theory to match experimental evidence is for the energy of light to be lost in unmeasureably tiny steps when it interacts with gravity over long distances and all it takes for that to be true is for light to have a tiny bit of mass, but most physicists wouldn’t like this because it would pull the rug out from underneath their reverse-engineered, standard model particle zoo and out from underneath all of neutrino science.
The discrepancy between big-bang and tired-light universes gives you an estimate of light’s mass, but people don’t try very hard to figure these things out when astronomers frame tired-light as a straw man and insist on mis-applying relativity.
Does the math work out if we just start calling neutrinos light? I genuinely don’t know, but the amount of nonsense I’ve seen in physics has caused me to take even crazy sounding questions seriously.
Meanwhile the questions that are taken seriously within cosmology involve an incomprehensible incompatibility of big-bang general relativity with quantum mechanics and this ‘mystery’ has been used to ask politicians for more money for the past sixty years.
What I notice in typical pop-sci writing is how tired-light, steady-state, gravitoelectromagnetism, and plasma cosmology are each individually knocked down as straw men and that this is a divide and conquer technique because those four theories are very much the same when combined in one, unified framework. It is only when they are separated and given their weakest interpretations that they fall down in comparison to the state-subsidized big-bang theory.
What is really bothersome about this style of thinking and marketing is that the issue is painted in either/or terms when a recursive, self-similar, fractal definition of the system may be more appropriate. We clearly have flat space over some length scales and curved space over others, just as the Earth is flat when you are standing on it and curved when you are high above it. I suspect that the universe works the same way and when we approximate curved things as flat and flat things as curved, there is something deeper going on regarding a self-similar, fractal structure in which light acts more and less tired depending on how curved or turbulent the space is. (Recall that curve and turbulence are two ways to say the same thing in the post tower-of-Babel world of physics.)
……….
It may not seem that silly questions of language and theory matter, but how people view the cosmos has profound psychological impacts and when a community congeals around one, narrow viewpoint, it can bury experimental work that broaden’s people’s perspective.
One person’s work what has been buried is that of Halton Arp.
Halton Arp studied quasars and noticed that they often seemed to be in the vicinity of strangely shaped galaxies. He suggested that quasars’ extremely large redshifts might be interpreted in two very different ways:
- quasars are extremely far-away, baby galaxies and their redshift is caused by the accelerating expansion of the universe.
OR
- quasars are not so far-away and their redshift might be caused by their ejection from the center of a nearby galaxy.
How might one decide between these two options? Take data, of course. But what happens when the only people who are given money to take data are the people who believe that quasars are baby galaxies? Hmmm. Something very non-scientific happens. The people who want to study the idea that quasars have been ejected by nearby galaxies get marginalized and excluded from conferences. They are not given access to telescopes or students.
Ignoring the politics, I look for counterexamples to disprove a theory. In the case of the baby galaxy quasar theory, one might look no further than quasar 3C279 observed in 1971.
Quasar 3C279 appeared to be ejecting something that was moving away from the quasar core at ten times the speed of light and, over the following years, several more examples of quasars with this strange feature were found.
In more detail, the jet of quasar 3C279 moves away from the quasar core at a rate of about three-quarters of a milliarcsecond per year but the redshift of the quasar indicated a distance of about 2.6 billion light years. A path at this distance that extends over three-quarters of a milliarcsecond in the sky, is more than nine light years long. Thus, the component appears to traverse 9 light years in the course of a single year. This would make it nine times as fast as light. In addition, the motion that we observe is only the transverse part.
Motion near the cosmic speed limit
How did big-bang cosmologists explain away this physically impossible result? They invented another, physically impossible result to counteract it, of course. If the jet just happens to be shooting towards us at the speed of light, for whatever reason, this would explain the apparent faster-than-light motion of the transverse components. In other words:
There could be an additional (unobserved) velocity component of unknown size in the direction of the line of sight. If the unknown velocity component in the direction of the line of sight is nearly equal to the speed of light, then the light travel times come into play as described above. The velocity is overestimated and even the (smaller) transverse component may appear to exceed the speed of light. The observed superluminal motion in the jet of 3C273 can be explained by a jet that moves at more than 99 percent of the speed of light and approaches us almost along our line of sight.
Motion near the cosmic speed limit
I don’t buy that reasoning and it seems like a pretty weak leg on which to balance all of big-bang cosmology.
What happened? Were idiots directing the research dollars or were they directing the research dollars based on goals that had absolutely nothing to do with figuring out what is true? My guess is that the latter was the case. The people controlling the purse strings would choose research programs which would strengthen their control over a larger portion of the research pie. When big-bang cosmologists and quarky collider physicists teamed up to create a single narrative, they ate the whole pie.
For more mysterious quasar behavior, try: Does the recent discovery of a Large Quasar Group (LQG) at a redshift (z = about 1.3) linked to another LQG at the same redshift deal a death-blow to standard cosmology?
……..
Changing a majority opinion is difficult when true believers say that the big-bang theory should be chosen based on the depth of the body of work which has already been produced. I don’t think that is logically sound. You can have a deep yet wrong theory and a shallow yet right theory. As in the case of Halton Arp’s work on quasars, the depth just hasn’t been achieved because efforts have been invested elsewhere.
I’ll wrap this up with a series of questions posed by a big bang physicist to a tired light physicist:
“What is the theoretical basis for tired light?”
The idea is that there is a fluid-like aether which slowly takes energy away from a light wave which is propagating through it along curved trajectories. This makes the light coming from more distant galaxies appear to have a longer wavelength (red-shift). In order to match the point-like appearance of light in the night sky, this energy loss must be non-discrete on the atomic scale, i.e. not corresponding to quantum scattering processes. If there is such a thing as a graviton, it might, however, be discrete on the scale of planetary bodies.
“Why do high redshift galaxies have different chemical composition? Why do they look less mature? ”
The light from the stars took a long time to get to us, so what we see was generated a long time ago, and if all of the stars started to burn at around the same time, that is why the night sky is not uniformly filled with light. That age old, Olbers’ paradox explanation fits with either a big-bang or with tired-light, but if you want to describe a steady-state universe instead, you need a model of the universe as a fractal circuit in which light is continuously exchanged between stars. It is harder to wrap your mind around that picture, but it is possible.
Why does the large scale distribution of matter obey certain statistical laws?
Fractal structures obey certain statistical laws and our universe is certainly self-similar over many key length scales. On this point, the main difference between a big bang perspective and a tired light perspective is in how they each define space. The big banger says that the space between things changes depending on relative motion while the tired light theorist might say that the space (distance) only appears to change depending on relative motion. For example, if you and someone behind you are both accelerating through some substance, the more you accelerate, the more the space between you will act like it is larger, even if the distance between you didn’t actually change. How you interpret the situation is just a matter of convention. Some conventions are easier to understand than others and I would argue that the least counterintuitive description should win the game, i.e., when you explain it to your grandma, she shouldn’t think that you are nuts – as is often the case with the exploding bubble big-bang story. Concerning the big-bang, my inner grandma still asks, ‘How can two galaxies be moving apart at faster than the speed of light if nothing can travel at faster than the speed of light?’ My inner physicist answers, “Blah, blah, de Sitter space,” but this never fully satisfies my inner grandma. I have to remind her that it is impossible to think in Riemannian, Minkowski, de Sitter space – it is just a trick used to make certain calculations easier, but many physicists forgot and started confusing the map and the territory.
“Why is there a cosmic microwave background?”
Empty space is warmed up by the light of the stars. If space were truly empty, then the light wouldn’t lose energy as it traveled through it. Big-bang theorists mystification of the cosmic microwave background resulted from the assumption that space is empty.
“Why is its angular power spectrum what it is?”
The power spectrum of temperature fluctuations in the Cosmic Microwave Background – animation When energy flows through an inhomogeneous medium as in rivers of light produced by stars, it concentrates in bottlenecks and is relatively homogeneous at a distance from the bottlenecks. The peaks in the spectrum correspond to various length scales (correlation lengths) over which there is homogeneity and connectivity. Where energy concentrates, you get negative entropy (order) and time travels forwards. In a Riemanian/Minkowski/de Sitter/general relativity metric, the light travels straight ahead, but the space curves. In a Cartesian metric, the light travels along curved rivers, but the space is flat. In order to understand how this works, you need to return to Cartesian thinking and learn about renormalization.
“Why do primordial hydrogen, deuterium and helium have the observed ratios?”
Hoyle, the inventor of nucleosynthesis, believed in a steady-state, tired-light universe and he didn’t believe in a big-bang. The big-bang believers labeled him as a fringe thinker at the same time that they were adapting his nucleosynthesis ideas to their own framework. I think that tired-light and steady-state universes are only ‘debunked’ or ‘fringe’ in the minds of people who set them up as straw men in order to support the image of the big-physics industry as powerful, single-minded, and all-knowing when, upon closer inspection, it is anything but.
It is instructive to compare this narrative to the most recent annoucement of the Nobel Prize in Physics.
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I first posted this material on quora.com and I’m compiling my science writing into a two book set, but instead of editing that work, I am procrastinating by blogging. Maybe I’ll be able to publish the first book by Christmas. Until then, the only long-form work I have published is in the form of fiction that is safe for kids while being interesting for adults.
I’ve been trying to learn to write in an accessible manner about topics that are widely believed to be too complicated to understand. Any feedback you can offer is welcome.
Kirsten Hacker 