8 ms·

I think this says less about cosmology and more about the incredibly effectiveness of the standard model in the regime we can test directly on earth. If we com

I think this says less about cosmology and more about the incredibly effectiveness of the standard model in the regime we can test directly on earth. If we compare ΛCDM to most other scientific theories it doesn't look so bad in terms of discrepancies. Certainly there are many unexplained effects in solid state physics, there isn't even an accepted explanation for why rubbing a balloon on your head makes it stick to a wall and that's an experiment you probably did as a child.

Eduard 4y ago
> there isn't even an accepted explanation for why rubbing a balloon on your head makes it stick to a wall But the accepted explanation is "static electricity", no? Or do you mean we don't "really" know when asking a couple of follow-up "why?" questions further?
- beambot 4y ago
  This is the triboelectric effect, and the low-lying mechanisms are poorly understood & poorly characterized.
  - Eduard 4y ago
    Reading https://en.m.wikipedia.org/wiki/Triboelectric_effect https://en.m.wikipedia.org/wiki/Triboelectric_effect , I have the impression the mechanisms are not _that_ poorly understood, at least from my layman's perspective.
    - JimBlackwood 4y ago
      It's in the lines: > The triboelectric effect is very unpredictable, and only broad generalizations can be made. > The mechanisms of triboelectrification (or contact-electrification) have been debated for many years, with possible mechanisms including electron transfer, ion transfer or the material's species transfer. > Recent studies in 2018 using Kelvin probe microscopy and triboelectric nanogenerators revealed that electron transfer is the dominant mechanism for triboelectrification between solid and solid. > For a general case, since triboelectrification occurs for any material, a generic model has been proposed by Wang, in which the electron transfer is caused by a strong electron cloud overlap between two atoms for the lowered interatomic potential barrier by shortening the bonding length. So, still very much misunderstood. There is an experiment showing the dominant mechanism (so still only explaining a part!) between solid-solid and a generic model proposed that can be used to explain other interactions (solid-liquid, liquid-liquid, etc). Unless there's a tested model with predictable results, I'd say we're not really understanding it properly.
      - bardworx 4y ago
        > So, still very much misunderstood. There is an experiment showing the dominant mechanism (so still only explaining a part!) between solid-solid and a generic model proposed that can be used to explain other interactions (solid-liquid, liquid-liquid, etc). This seems like a very large part, no? I mean, we know it works, we get the majority of it, and it doesn’t seem super necessary to spend a lot of dollars and brain power to satisfy an internet debate on a theory of rubbing a balloon on one’s head.
        JimBlackwood 4y ago
        Sorry for my late response. Anyway: I get your point. However, this is worked on by researchers who get paid to work on unsolved problems. This is one of them. It's a surprising one, since it looks like such a simple and obvious effect governed by physics we've (seemingly) understood for centuries. Gauss's Laws are from 1773 and much of the work on static electricity is from that era. So, it's not just an internet debate. Knowing how things work _exactly_ is what scientists do. Getting the majority is not good enough. And yes, that will often surpass the scale of "Is what we're doing useful?". However, won't know until we find out. Most likely understanding this effect will not bring any revolutionary insight but we should understand it nonetheless. Maybe our understanding will help someone else solve a problem, that solves another problem, that solved another problem, that gives someone a brilliant idea.
        bardworx 4y ago
        Maybe there are researchers who want to study the discrepancies of static electricity but if they don’t get funding, then they won’t be paid and have to take other priorities. Seeming to demand these problems are resolved is a road to cynicism, in my opinion.
    - deleted 4y ago
      [deleted]
- jpttsn 4y ago
  At that point why not call it “witchcraft;” a sciencey word for something is not an explanation.
  - moffkalast 4y ago
    Clearly you've never recalibrated the thermal interferometery scanner so you can reverse the polarity of the neutron flow in the isoneutronic pulse wave carrier.
    - TeMPOraL 4y ago
      That's technobabble - a pejorative term for a technical word salad that usually is an explanation, just not a very good one.
    - voldacar 4y ago
      A good retroencabulator helps a lot here.
    - alfor 4y ago
      You need a plumbus for that. Everyone need one.
  - vaidhy 4y ago
    We do not call it witchcraft, because that is the end of the discussion and the answer. We call it unknown because it is knowable and is the beginning of the experiments.
    - dylan604 4y ago
      >We do not call it witchcraft, because that is the end of the discussion and the answer. Also, we'd have to eliminate the practitioners for clearly being witches. We've had that period and history, but it seems some modern day people are content to bring that very time period back.
  - dmitriid 4y ago
    Hail science https://youtu.be/tl55gVXsBZE https://youtu.be/tl55gVXsBZE
- Sharlin 4y ago
  "Static electricity" as an explanation without follow-up "why?" questions is just a curiosity-stopper [1] or guessing the teacher's password [2]. [1] https://www.lesswrong.com/posts/L22jhyY9ocXQNLqyE/science-as-curiosity-stopper https://www.lesswrong.com/posts/L22jhyY9ocXQNLqyE/science-as... [2] https://www.lesswrong.com/posts/NMoLJuDJEms7Ku9XS/guessing-the-teacher-s-password https://www.lesswrong.com/posts/NMoLJuDJEms7Ku9XS/guessing-t...
- deleted 4y ago
  [deleted]
foxyv 4y ago
> there isn't even an accepted explanation for why rubbing a balloon on your head makes it stick to a wall You mean dielectric moments and static electricity? Electromagnetism is the one thing we know the most about. It's that spooky gravity junk that makes us scratch our heads. It never seems to behave quite right and doesn't mesh with all the other forces.
- gwd 4y ago
  > You mean dielectric moments and static electricity? You're confusing what with why. My understanding is that everyone knows it has something to do with electrons collecting on the balloon; but nobody quite knows why rubbing rubber against hair causes the electrons to do that.
  - throwaway09223 4y ago
    Exactly. Often the gap between what and why is enormous. Humanity began curing meats to protect against microorganisms around 3000BC. The effect of what was going on was immediately observable, but it wasn't until 4500 years or so later that we discovered the why of microorganisms.
  - foxyv 4y ago
    I think I got confused because I was thinking about why it stuck to the wall, rather than why it accumulated charge. I know why electrically charged objects stick to things. The why of how they got like that is a bit different as you mentioned. Triboelectric effect is spooky, but there are some theories. It's one of those non-linear messy quantum things that's a pain in the neck to solve.
    - moloch-hai 4y ago
      > It's one of those non-linear messy quantum things that's a pain in the neck to solve. That is exactly equivalent to "dunno, maybe something".
      - 4y ago
tim-fan 4y ago
Relevant xkcd: https://m.xkcd.com/2682/ https://m.xkcd.com/2682/ And from the alt-text: "Friction-driven static electrification is familiar and fundamental in daily life, industry, and technology, but its basics have long been unknown and have continually perplexed scientists from ancient Greece to the high-tech era. [...] To date, no single theory can satisfactorily explain this mysterious but fundamental phenomenon." --Eui-Cheol Shin et. al. (2022)
- moffkalast 4y ago
  Reminds me of this one https://xkcd.com/1489 https://xkcd.com/1489 "Of these four forces, there's one we don't really understand." "Is it the weak force or the strong--" "It's gravity."
AnIdiotOnTheNet 4y ago
Also there's that whole "worst prediction in the history of physics" thing with the Vacuum Catastrophe.
vl 4y ago
>Certainly there are many unexplained effects in solid state physics Wait for it… Why ice is slippery? Usual explanation is completely incorrect. Actual semi-conclusive research just recently happened.
- hutzlibu 4y ago
  It is not, because ice has a smooth surface and that probably the surface layer melts a bit because your shoes are warm? That would be my reasoning, but it likely seems to be wrong, well why?
  - Sharlin 4y ago
    The usual hypothesis is that a microscopic layer of the surface melts, not because your shoes are warm, but because of the pressure. But the pressure is not enough to do that. That said, as anyone who has been in icy conditions can attest, it is clear that ice at ~0° C is vastly more slippery than at, say, -20°C.
    - darkerside 4y ago
      My understanding is that, at the borders, master is constantly changing between its states. A boiling pot has water molecules turning to steam, as well as vice versa. It just has more of the first probabilistically. Maybe the same happens with ice and water.
      - kortex 4y ago
        That's more or less it, as far as I understand. There's the hexagonal lattice of solid water ice, where hydrogen bonds form a 3D tetrahedral structure which is very stable. At the boundary, there are no molecules "above" the solid latice, so those water molecules are held less tightly. The exact dynamics are challenging to predict because we can't exactly see what's going on (most simulation based).
    - usrusr 4y ago
      The pressure from well distributed static load divided by area is not, but on the tiny scale where the difference between grippy and less grippy surfaces happens there isn't so much "well distributed" going on. And once you add lateral force to the mix all bets are off: there will always be a point getting better grip (is surface interference the correct term?) than others, see a local force concentration and when that causes a tiny spot of phase transition there will very soon be a new point of least local slippyness getting all the attention of lateral force.
azalemeth 4y ago
My favourite example of the intractabilities of some theories is that magnetohydronamics apparently can't predict the formation of streamer jets when you put your finger on a kid's plasma ball – i.e. the main point of the toy is beyond the most advanced theory that lies behind NIF, JET, ITER, etc...
- Buttons840 4y ago
  At this point in the thread, I'm wondering if we do a disservice to physics students by making it appear we have it all figured out.
  - treeman79 4y ago
    If it was all figured out why get into the field? Sure some do it just to know. But the hunt is what drives most.
  - maegul 4y ago
    So much this! There’s surely a huge argument that all of scientific education is a massive disservice. The point should be to learn and appreciate the method or process of scientific investigation of uncertain and mysterious or hard to understand phenomena. Instead we get dogma as a proxy of measuring intelligence with little regard for what the fundamental tools are of being a scientist. I’ve gone all the way through to Grad School and came out astounded at just how little commitment to or a sense of the essence of scientific investigation and what’s expected of the investigator there is in the system. They don’t prepare you for it because they themselves weren’t prepared. You can try to leverage some meta understanding of the “process” in conversation or debate, but so often the conversation falls flat because few are prepared or accustomed to it. Research is often done, IMO, in philosophical poverty by people eking out a living in the gutters of novelty and paradigmatic safety, averting their gazes from the sky (flourishes aside, you get my point). Putting aside the health of actual research. If the general public is to benefit from education and pass that benefit into their society (that’s the point right), it needs to be more than soon to be forgotten and often useless fallacies.
    - 4y ago
comicjk 4y ago
My understanding is that the standard model likely does predict static electricity, but since it's a phenomenon bigger than a few molecules, we have no way to actually run the simulation. The physics is willing but the computers are weak.
- bardworx 4y ago
  This seems incorrect as it’s just an imbalance of charge and isn’t a strange phenomena. Can you provide a reference, please?
TillE 4y ago
My favorite poorly understood phenomenon in basic physics is the Mpemba effect, where hot water can freeze faster than cold water under certain circumstances. It's just phase changes of water in a simple experiment you can do at home, and I think there's still no widely accepted explanation.
- thaumasiotes 4y ago
  You might want to find a phenomenon that everyone can agree exists. Failing to explain something that doesn't happen isn't very mysterious. https://en.wikipedia.org/wiki/Mpemba_effect https://en.wikipedia.org/wiki/Mpemba_effect > the actual occurrence of the Mpemba effect is a matter of controversy > In 2016, Burridge and Linden defined the criterion as the time to reach 0 °C (32 °F; 273 K), carried out experiments, and reviewed published work to date. They noted that the large difference originally claimed had not been replicated, and that studies showing a small effect could be influenced by variations in the positioning of thermometers: "We conclude, somewhat sadly, that there is no evidence to support meaningful observations of the Mpemba effect." > In controlled experiments the effect can entirely be explained by undercooling [water may cool below the freezing point without actually solidifying] and the time of freezing was determined by what container was used.
- NavinF 4y ago
  That's because nobody's replicated that effect in a real lab. People who claimed to observe effect didn't even bother to bypass the freezer thermostat and force the compressor to stay on, nor did they measure power consumption. It's just shoddy science.
WalterBright 4y ago
> there are many unexplained effects in solid state physics Looks like there is plenty of opportunity for newly minted physicists to make their names and careers!
simonebrunozzi 4y ago
> ΛCDM Lambda-CDM Model [0], for the ones like me who haven't heard it before. [0]: https://en.wikipedia.org/wiki/Lambda-CDM_model https://en.wikipedia.org/wiki/Lambda-CDM_model
gmadsen 4y ago
which part. how is that not electostatics and van der walls forces?
WithinReason 4y ago
The relevant XKCDs: https://xkcd.com/1867/ https://xkcd.com/1867/ https://xkcd.com/2682/ https://xkcd.com/2682/

Eduard 4y ago

> there isn't even an accepted explanation for why rubbing a balloon on your head makes it stick to a wall But the accepted explanation is "static electricity", no? Or do you mean we don't "really" know when asking a couple of follow-up "why?" questions further?

beambot 4y ago
This is the triboelectric effect, and the low-lying mechanisms are poorly understood & poorly characterized.
- Eduard 4y ago
  Reading https://en.m.wikipedia.org/wiki/Triboelectric_effect https://en.m.wikipedia.org/wiki/Triboelectric_effect , I have the impression the mechanisms are not _that_ poorly understood, at least from my layman's perspective.
  - JimBlackwood 4y ago
    It's in the lines: > The triboelectric effect is very unpredictable, and only broad generalizations can be made. > The mechanisms of triboelectrification (or contact-electrification) have been debated for many years, with possible mechanisms including electron transfer, ion transfer or the material's species transfer. > Recent studies in 2018 using Kelvin probe microscopy and triboelectric nanogenerators revealed that electron transfer is the dominant mechanism for triboelectrification between solid and solid. > For a general case, since triboelectrification occurs for any material, a generic model has been proposed by Wang, in which the electron transfer is caused by a strong electron cloud overlap between two atoms for the lowered interatomic potential barrier by shortening the bonding length. So, still very much misunderstood. There is an experiment showing the dominant mechanism (so still only explaining a part!) between solid-solid and a generic model proposed that can be used to explain other interactions (solid-liquid, liquid-liquid, etc). Unless there's a tested model with predictable results, I'd say we're not really understanding it properly.
    - bardworx 4y ago
      > So, still very much misunderstood. There is an experiment showing the dominant mechanism (so still only explaining a part!) between solid-solid and a generic model proposed that can be used to explain other interactions (solid-liquid, liquid-liquid, etc). This seems like a very large part, no? I mean, we know it works, we get the majority of it, and it doesn’t seem super necessary to spend a lot of dollars and brain power to satisfy an internet debate on a theory of rubbing a balloon on one’s head.
      - JimBlackwood 4y ago
        Sorry for my late response. Anyway: I get your point. However, this is worked on by researchers who get paid to work on unsolved problems. This is one of them. It's a surprising one, since it looks like such a simple and obvious effect governed by physics we've (seemingly) understood for centuries. Gauss's Laws are from 1773 and much of the work on static electricity is from that era. So, it's not just an internet debate. Knowing how things work _exactly_ is what scientists do. Getting the majority is not good enough. And yes, that will often surpass the scale of "Is what we're doing useful?". However, won't know until we find out. Most likely understanding this effect will not bring any revolutionary insight but we should understand it nonetheless. Maybe our understanding will help someone else solve a problem, that solves another problem, that solved another problem, that gives someone a brilliant idea.
        bardworx 4y ago
        Maybe there are researchers who want to study the discrepancies of static electricity but if they don’t get funding, then they won’t be paid and have to take other priorities. Seeming to demand these problems are resolved is a road to cynicism, in my opinion.
  - deleted 4y ago
    [deleted]
jpttsn 4y ago
At that point why not call it “witchcraft;” a sciencey word for something is not an explanation.
- moffkalast 4y ago
  Clearly you've never recalibrated the thermal interferometery scanner so you can reverse the polarity of the neutron flow in the isoneutronic pulse wave carrier.
  - TeMPOraL 4y ago
    That's technobabble - a pejorative term for a technical word salad that usually is an explanation, just not a very good one.
  - voldacar 4y ago
    A good retroencabulator helps a lot here.
  - alfor 4y ago
    You need a plumbus for that. Everyone need one.
- vaidhy 4y ago
  We do not call it witchcraft, because that is the end of the discussion and the answer. We call it unknown because it is knowable and is the beginning of the experiments.
  - dylan604 4y ago
    >We do not call it witchcraft, because that is the end of the discussion and the answer. Also, we'd have to eliminate the practitioners for clearly being witches. We've had that period and history, but it seems some modern day people are content to bring that very time period back.
- dmitriid 4y ago
  Hail science https://youtu.be/tl55gVXsBZE https://youtu.be/tl55gVXsBZE
Sharlin 4y ago
"Static electricity" as an explanation without follow-up "why?" questions is just a curiosity-stopper [1] or guessing the teacher's password [2]. [1] https://www.lesswrong.com/posts/L22jhyY9ocXQNLqyE/science-as-curiosity-stopper https://www.lesswrong.com/posts/L22jhyY9ocXQNLqyE/science-as... [2] https://www.lesswrong.com/posts/NMoLJuDJEms7Ku9XS/guessing-the-teacher-s-password https://www.lesswrong.com/posts/NMoLJuDJEms7Ku9XS/guessing-t...
deleted 4y ago
[deleted]

foxyv 4y ago

> there isn't even an accepted explanation for why rubbing a balloon on your head makes it stick to a wall You mean dielectric moments and static electricity? Electromagnetism is the one thing we know the most about. It's that spooky gravity junk that makes us scratch our heads. It never seems to behave quite right and doesn't mesh with all the other forces.

gwd 4y ago
> You mean dielectric moments and static electricity? You're confusing what with why. My understanding is that everyone knows it has something to do with electrons collecting on the balloon; but nobody quite knows why rubbing rubber against hair causes the electrons to do that.
- throwaway09223 4y ago
  Exactly. Often the gap between what and why is enormous. Humanity began curing meats to protect against microorganisms around 3000BC. The effect of what was going on was immediately observable, but it wasn't until 4500 years or so later that we discovered the why of microorganisms.
- foxyv 4y ago
  I think I got confused because I was thinking about why it stuck to the wall, rather than why it accumulated charge. I know why electrically charged objects stick to things. The why of how they got like that is a bit different as you mentioned. Triboelectric effect is spooky, but there are some theories. It's one of those non-linear messy quantum things that's a pain in the neck to solve.
  - moloch-hai 4y ago
    > It's one of those non-linear messy quantum things that's a pain in the neck to solve. That is exactly equivalent to "dunno, maybe something".
    - 4y ago

tim-fan 4y ago

Relevant xkcd: https://m.xkcd.com/2682/ https://m.xkcd.com/2682/ And from the alt-text: "Friction-driven static electrification is familiar and fundamental in daily life, industry, and technology, but its basics have long been unknown and have continually perplexed scientists from ancient Greece to the high-tech era. [...] To date, no single theory can satisfactorily explain this mysterious but fundamental phenomenon." --Eui-Cheol Shin et. al. (2022)

moffkalast 4y ago
Reminds me of this one https://xkcd.com/1489 https://xkcd.com/1489 "Of these four forces, there's one we don't really understand." "Is it the weak force or the strong--" "It's gravity."

AnIdiotOnTheNet 4y ago

Also there's that whole "worst prediction in the history of physics" thing with the Vacuum Catastrophe.

vl 4y ago

>Certainly there are many unexplained effects in solid state physics Wait for it… Why ice is slippery? Usual explanation is completely incorrect. Actual semi-conclusive research just recently happened.

hutzlibu 4y ago
It is not, because ice has a smooth surface and that probably the surface layer melts a bit because your shoes are warm? That would be my reasoning, but it likely seems to be wrong, well why?
- Sharlin 4y ago
  The usual hypothesis is that a microscopic layer of the surface melts, not because your shoes are warm, but because of the pressure. But the pressure is not enough to do that. That said, as anyone who has been in icy conditions can attest, it is clear that ice at ~0° C is vastly more slippery than at, say, -20°C.
  - darkerside 4y ago
    My understanding is that, at the borders, master is constantly changing between its states. A boiling pot has water molecules turning to steam, as well as vice versa. It just has more of the first probabilistically. Maybe the same happens with ice and water.
    - kortex 4y ago
      That's more or less it, as far as I understand. There's the hexagonal lattice of solid water ice, where hydrogen bonds form a 3D tetrahedral structure which is very stable. At the boundary, there are no molecules "above" the solid latice, so those water molecules are held less tightly. The exact dynamics are challenging to predict because we can't exactly see what's going on (most simulation based).
  - usrusr 4y ago
    The pressure from well distributed static load divided by area is not, but on the tiny scale where the difference between grippy and less grippy surfaces happens there isn't so much "well distributed" going on. And once you add lateral force to the mix all bets are off: there will always be a point getting better grip (is surface interference the correct term?) than others, see a local force concentration and when that causes a tiny spot of phase transition there will very soon be a new point of least local slippyness getting all the attention of lateral force.

azalemeth 4y ago

My favourite example of the intractabilities of some theories is that magnetohydronamics apparently can't predict the formation of streamer jets when you put your finger on a kid's plasma ball – i.e. the main point of the toy is beyond the most advanced theory that lies behind NIF, JET, ITER, etc...

Buttons840 4y ago
At this point in the thread, I'm wondering if we do a disservice to physics students by making it appear we have it all figured out.
- treeman79 4y ago
  If it was all figured out why get into the field? Sure some do it just to know. But the hunt is what drives most.
- maegul 4y ago
  So much this! There’s surely a huge argument that all of scientific education is a massive disservice. The point should be to learn and appreciate the method or process of scientific investigation of uncertain and mysterious or hard to understand phenomena. Instead we get dogma as a proxy of measuring intelligence with little regard for what the fundamental tools are of being a scientist. I’ve gone all the way through to Grad School and came out astounded at just how little commitment to or a sense of the essence of scientific investigation and what’s expected of the investigator there is in the system. They don’t prepare you for it because they themselves weren’t prepared. You can try to leverage some meta understanding of the “process” in conversation or debate, but so often the conversation falls flat because few are prepared or accustomed to it. Research is often done, IMO, in philosophical poverty by people eking out a living in the gutters of novelty and paradigmatic safety, averting their gazes from the sky (flourishes aside, you get my point). Putting aside the health of actual research. If the general public is to benefit from education and pass that benefit into their society (that’s the point right), it needs to be more than soon to be forgotten and often useless fallacies.
  - 4y ago

comicjk 4y ago

My understanding is that the standard model likely does predict static electricity, but since it's a phenomenon bigger than a few molecules, we have no way to actually run the simulation. The physics is willing but the computers are weak.

bardworx 4y ago
This seems incorrect as it’s just an imbalance of charge and isn’t a strange phenomena. Can you provide a reference, please?

TillE 4y ago

My favorite poorly understood phenomenon in basic physics is the Mpemba effect, where hot water can freeze faster than cold water under certain circumstances. It's just phase changes of water in a simple experiment you can do at home, and I think there's still no widely accepted explanation.

thaumasiotes 4y ago
You might want to find a phenomenon that everyone can agree exists. Failing to explain something that doesn't happen isn't very mysterious. https://en.wikipedia.org/wiki/Mpemba_effect https://en.wikipedia.org/wiki/Mpemba_effect > the actual occurrence of the Mpemba effect is a matter of controversy > In 2016, Burridge and Linden defined the criterion as the time to reach 0 °C (32 °F; 273 K), carried out experiments, and reviewed published work to date. They noted that the large difference originally claimed had not been replicated, and that studies showing a small effect could be influenced by variations in the positioning of thermometers: "We conclude, somewhat sadly, that there is no evidence to support meaningful observations of the Mpemba effect." > In controlled experiments the effect can entirely be explained by undercooling [water may cool below the freezing point without actually solidifying] and the time of freezing was determined by what container was used.
NavinF 4y ago
That's because nobody's replicated that effect in a real lab. People who claimed to observe effect didn't even bother to bypass the freezer thermostat and force the compressor to stay on, nor did they measure power consumption. It's just shoddy science.

WalterBright 4y ago

> there are many unexplained effects in solid state physics Looks like there is plenty of opportunity for newly minted physicists to make their names and careers!

simonebrunozzi 4y ago

> ΛCDM Lambda-CDM Model [0], for the ones like me who haven't heard it before. [0]: https://en.wikipedia.org/wiki/Lambda-CDM_model https://en.wikipedia.org/wiki/Lambda-CDM_model

gmadsen 4y ago

which part. how is that not electostatics and van der walls forces?

WithinReason 4y ago

The relevant XKCDs: https://xkcd.com/1867/ https://xkcd.com/1867/ https://xkcd.com/2682/ https://xkcd.com/2682/