Question Question about the scale of the universe

Nov 27, 2020
Visit site
How far can we go in our ambition to finding the smallest particle in the universe? And how far can we go in our ambition to know how big universe is

What are your opinions?
Last edited by a moderator:
A smallest thing might not exist in the universe.
Things could just keep getting smaller forever.

If a smallest thing does exist it opens a can of worms about (nothing) being between the smallest things.
Nothing properties= no space, no time and no ruler to the next thing.
Our understanding of reality will be totally wrong.

  • Like
Reactions: Catastrophe
Jul 27, 2021
Visit site
As far as we are capable of trying more and better, refining the theories and experiments. As long as we are alive.

With conditions:

  1. There is the same interest: (scientific, economical, etc.) and the same trend of working on fundamental sustainability with genius/hard workers leaps.
  2. Generation Z inherited or neglected ambitions.

'We'll keep on trying till the end of times..'
  • Like
Reactions: Catastrophe
Jan 13, 2020
Visit site
Our universe is all we could ever know. It grows every day. We know about how big it is. That doesn't mean that is all there is, though. So, can we ever know how "big" all there is... is?

I don't think so. I think that's a hard no for us. Higher dimensional beings could discover it and conveys it to us, maybe?
Sep 15, 2021
Visit site
According to the Theosophical Society, matter is nothing at all, merely whirls, holes, disturbances in the ether that are the ultimate "atom". Before science gets there, it has to realize that there is this matrix or ether underlying everything. In the beginning there was the Chaos, whatever that means, then there were those tiniest of all whatevers, then who knows what went next, maybe a Big Bang or maybe not. Coming back to Earth, not everybody thinks that the Michelson-Morley experiment proved that there was no ether that Earth was moving through. Maybe none of the above makes any sense, or maybe it does, but the space aliens refuse to explain. All they do is keep repeating that we're all just a bunch 'a radicals, worthless rough element, one step away from some sort of really nasty Armageddon, which is all we deserve.
We can only go as far as our lifespan will allow.
Threescore years and ten and if by strength, fourscore and a bit more.
Mortality is something we have to accept as far as our natural lives.
Did you ever ponder as a child what lies at the end of the universe, and then what is beyond that? I did.
There is probably no limit to how far or how small.
Mankind likes to pigeonhole everything and use science and math to explain what he observes but he struggles with important questions such as what was there before the beginning, before t = 0? where did we come from? What is infinity? because infinity cannot be contained.
So perhaps infinity is the only true reality. World without end. Only man is bound by time!
  • Like
Reactions: Catastrophe
Sep 15, 2021
Visit site
"There is probably no limit to how far or how small. " (Terra Austr.)

Others say there's a limit on the latter, the near end, which would be the Larssonian Theory.

That first comment of mine here was hasty, careless & regrettable. I was out in the streets, standing with the tablet next to the windows of a supermarket that has a strong Wi-Fi signal, far away from my piles of notebooks. Now I'm there again, but with the pertinent data.

Some physicists think that the true, ultimate, structureless, & thus indivisible, atom is inaccessible, & that we will keep finding ever smaller subatomic particles, beyond the quark, others deny that & believe what Thorbjorn Larsson replied at the UniverseToday website 10 yrs. ago when I said that at a lecture a physicist told us that there could be an infinite sequence of subatomic building blocks, so that we would never reach the end.

"No, for whatever reason, likely to keep physics regulated from a UV-catastrophe, particles hit the Planck energy limit. That gives, observably, a discrete measure to entropy, and if you go through the numbers there are only so many particles and so many interactions (fields)."

That was in a discussion following a report titled "Do galaxies recycle their material?"

The UV catastrophe was a theoretical difficulty that physics ran into & forced it to find a way out.

Larsson's scholarly comments were always on a professional level & hard to follow, & making things even worse was that, as he told us, he had never learned English on a formal basis & was learning it right there, as he read our comments, so what we need here is the presence of resident physicist Hanneke Weitering, who will please be so kind as to decodify for us that piece of Larssonian gibberish.

I'm using my real name so that if mein lieber Herr Professor Doktor Larsson ever comes around he'll remember the few discussions we had when we were somewhat younger & nattier.

That's not anything like how asteroids are bein
Last edited:
  • Like
Reactions: Terra Australis
Sep 15, 2021
Visit site
... asteroids are being treated. An asteroid was given the name of the creator of the said website, a Mr. Fraser Cain. Several of them have the names of people on astronomy magazine staffs, but it's nice to have one named after Anne Frank, if you've read her diary.

This matter of naming space rocks after people who are still alive is outrageously self-serving. In the U.S. no one who has not already gone back to dust & ashes can appear on a stamp, & a similar rule should be applied to all celestial bodies. Will please do something about this? It would have to be a worldwide Campaign To Get Rid of Living People's Names On Asteroids.
Sep 15, 2021
Visit site
Planck units define the minimal sizes for time, length, etc. These units are the least one can get that is applicable within science. There is no evidence that something smaller might not exist but this seems to be an area of supposition, not science.

Nice having someone around with the know-how. If that matter is not proven knowledge yet then maybe there are other schools of thought, besides the no-more-particles & the more-&-more-particles crowds. We must find out where Hanneke stands concerning this puzzle.
Nov 10, 2020
Visit site
In Quantum Field Theory what we call particles are really the smallest quanta of energy carried within a particular quantum field hence the definition of size becomes murky in fact there is evidence to support that the very notion of space (or alternatively time though the latter seems less likely)will likely break down at some scale. There are two major experimental results the Bell's inequality test and the quantum eraser delayed choice experiments which effectively show that either space or time is an emergent phenomenon that is not fundamental.

While we lack a final answer on this there is relevant work studying a type of quantum superconductor system that has been called "artificial atoms" due to the systems having well defined energy states has shown that at least in complex many particle quantum systems described by a single wavefunction the change in state of a quantum system is continuous which lends weight towards time being more fundamental than space. (In which case the construct of spacetime in GR emerges as a consequence of time acting as a generator of space through some mechanism)

What needs to be recognized is that at the quantum scale the notion of size at best becomes a matter of the wavelength of the local quantum wavefunction rather than any sort of physical object thus the question you ask regarding finding the "smallest" particle becomes poorly defined In particular the Heisenberg uncertainty principal places upper limits on our ability to probe space at least without paying in an uncertainty of momentum. The high uncertainty has the consequence that probing smaller and smaller length scales requires proportionally larger amounts of energy and thus according to our current theories which we know are incomplete at some point the gravity of the system becomes important and in the conventional picture drives the formation of a micro black hole. This is probably incomplete but without a theory of quantum gravity we can not say what happens below the plank length threshold or even if anything exists below that unit of length.

To go smaller we need a framework for quantum gravity there are a few prospective candidates but all of them have problems unifying General Relativity(GR) and Quantum Field Theory(QFT) particularly in the form of renormalization terms which blow up to infinity.

String Theory is one such candidate though it rests on another model called Supersymmetry which is on increasingly shaky ground having failed in virtually all of its theoretical predictions with remaining model variations having to make increasingly convoluted "corrections" that shift these predicted particles to higher and higher energies. Then there is also the issue string theory has with requiring additional spatial dimensions that hasn't been resolved. Were it to be validated as a framework it predicts the existence of oscillating "strings" which exist below the plank scale and generate familiar matter as various wave oscillations of these strings. In this model these strings thus would be the smallest unit.

Its main competitor Quantum Loop Gravity has similar issues having failed on a few potential predictions that required gravitational waves to travel slightly slower than light I don't know for sure if that flaw has been worked around entirely but it doesn't seem to be completely dead as a concept.

There is an interesting prospective with Wolfram's physics project and their underlying rules for which a Turing machine must obey when operating on some existing network Notably it reproduces a generalized for of the Einstein field equations where space is a type of emergent property that arises from network connectivity and the ability for updates to propagate through the network. It also introduces a few other types of space that arise points towards other types of space based properties such as the ordering of updates driving entanglement and branchial space which forms the framework for quantum mechanics when viewed as a projection. The last of these "spaces" is rulial space the space where the algorithm gets to vary. Point is again this predicts sub plank length structure though its hard to say what and how those precise model rule dependent features would look.

In summary we don't know and future progress depends on the active theoretical development of quantum gravity.
In a likely vain attempt to convert some points within your nice post into Helioeeze, I'll at least give it a try.

There are two major experimental results the Bell's inequality test and the quantum eraser delayed choice experiments which effectively show that either space or time is an emergent phenomenon that is not fundamental.
Is this "emergence" what I read about where the sum of the parts may not equal the whole?

... which lends weight towards time being more fundamental than space. (In which case the construct of spacetime in GR emerges as a consequence of time acting as a generator of space through some mechanism).
That's interesting. Is GR applicable only when the sum of the parts do equal the whole? [Assumes my prior statement is correct.]

...To go smaller [than the Plank scale] we need a framework for quantum gravity there are a few prospective candidates but all of them have problems unifying General Relativity(GR) and Quantum Field Theory(QFT) particularly in the form of renormalization terms which blow up to infinity.
Is there a chance any such model could be experimentally tested directly, or just highly unlikely?
  • Like
Reactions: Catastrophe
Small and large are as much a matter of distance as here and there in space and time. Toss out a fishing line. Toss it farther with more line. Farther and more line. Ever farther and ever more line. What weight was the fishing line itself? What weight is the gain in fishing line itself now? It gains weight speedily the more fishing line is required to toss farther out. Eventually you reach a point where the fishing line's weight -- you are trying to toss -- is infinity. You've reached a weighty horizon of collapse, to zero, in distance you can toss that totality of fishing line. At your end the mass of the fishing line is almost indistinguishable from infinitesimal. At the other end the total mass of the fishing line in its total length is almost indistinguishable from infinite. At that (closed systemic -- the fishing line) end, 'c' and the Planck Big Bang horizon.

You would have to move toward the distant to gain some room for your limited and limiting capability. It wouldn't help, not even if you moved an infinite distance. The collapsed horizon of farthest possibility would remain exactly the same; would remain constant to you.... the same weight of infinity in the end and totality of fishing line, the same zeroing, then, to any attempt -- and all capability -- to toss the hook beyond the horizon. A horizon then relatively constant to you. Real it may not be the Universe (U) you travel, but real it will always be to your reel of fishing line... to your finite, local, relative, universe (u).

It would only be in movement, in travel (could only be in movement, in travel), that you would realize there to be more: For you to realize the possibility -- even the possibility -- of boundarylessness.
Last edited:
IMO there isn't something smaller than quarks (strings aside if that theory is correct). Anyway, even if something smaller existed, we can't discover a particle smaller than the plank lenght, as already said in post #9.
Talking about the extremely high, I only know that the radius of the observable Universe is about 45 light years...
  • Like
Reactions: Catastrophe
vincenzosassone: I've made mistakes in posts at times on other sites, and I certainly got corrected and even ridiculed for it.

This was the reason I joined

I like this forum because people aren't so ready to jump on you if you make a mistake.

Something I discovered is how much the observable universe has increased over time as instrumentation and technology improve.

Amazing thing isn't it that we are peeking so far back in time?
Last edited:


"Science begets knowledge, opinion ignorance.
How far can we go in our ambition to finding the smallest particle in the universe? And how far can we go in our ambition to know how big universe is?

Smallest: You not only have to think about the smallest entities, but those which can be used to measure something very small. Of course, it is not some very small entity which must be use in measurement. For example, you might use the wavelength of light. Thus, to follow this idea, you could use the smallest wavelength of the electromagnetic spectrum.

Universe. We are limited by what defines the observable Universe. Thus the expansion of the Universe and the speed of light are, together, the limiting factor(s).

Cat :)
  • Like
Reactions: Terra Australis
Science is only a tool. I wish people would stop worshipping it as a divinity. I've read again and again historians like Will Durant being amazed how much people of 1000 CE and 2000 CE (approaching (Will Durant) at the time) mirror each other regarding their religious zealotry. Only in 2000 CE the religion is "Science" and scientists are the priests.... man-gods to some.

Quanta Magazine has a lead article out today on the strong force. I enjoyed it very much. Particularly such words from the professional scientists as, "We don't know," and similar words to the same effect. Such scientists attempt to map territories, they use science as tools like anyone else uses tools to work with in their profession, even their hobby and/or art, whatever. They do not claim divinity for themselves or their profession, or their views of the Universe at large / small. Like the philosopher-physicist who would not deny the old lady's belief that the universe rested on the back of a turtle, and that it was turtles all the way up and down (a really amazing similarity to 'planes' in chaos theory), they admit -- like Stephen Hawking -- there are things even in their own fields they have their opinions on but really do not know for facts. They, these particular scientists at least, do not savage opinions... they had only opinions going in. Knowledge begins as opinion, even fiction and fantasy. What was fiction and fantasy long ago (Jules Verne, for one opinionated writer), quite often is material fact today.

Discovery and/or invention all too often does not come from any professional scientist, but from an everyday common tool using nobody who simply had an idea... and an opinion.

Some professional scientists went in the other direction, the wrong direction, with their supposed great knowledge... attached to their opinions. Lord Kelvin's opinion that heavier than air ships could never fly. Von Neumann's opinion that computers would eventually have to occupy block size warehouse-like buildings and more, and only the largest, richest, nations and corporations would ever be able to afford one.

Science, and scientific method, is strictly a tool and should never be made into, and worshipped for, a religion. Again I wish people would stop pushing it for a religion; an elitist religion at that. They really do nothing more than stiff it.
Sept 27, 2021
The measurables (Matter-Energy, ME) are related to E=mc2 (and QED), QCD, Planck limits (h), Gravitation (speed), Action at a distance (Quantum pairing), some in Standard Model and some Beyond SM, etc. Smallest particles are commonly measured using these (including radiation probes).

What I believe is that these are all being explored very hard through research and experimentation (Cosmology observations, LHC, etc.) to arrive at the physical limits of Dark Matter. DM is what creates spacetime-structure [Universal Geometry for free particles and radiation space and Affine Geometry where bound structures (nucleus and electron orbits) are found]. DM is where matter-energy are created from and where these disappear.

I am still not clear about whether Dark Energy - DE is an equivalence to known phenomena or those not yet known hence I defer it from comment.

This puts limits on the smallest particle and DM creates non-ME particles in multidimensional space that eventually manifest as ME particles like those in SM.
Dr Ravi Sharma

Latest posts