Five things we still don’t know about water • Hacker News Board

Re: Five things we still don’t know about water

#101

Post by fouric » Thu, Oct 21, 2021, 1:47 AM UTC

betenoire wrote: post #99

fouric wrote: post #95

Earlier quoted context omitted.

"Conspiracy theory" is usually used in the non-technical sense of the word to be derogatory, or imply that the theory is false; conspiracy theories that the writer doesn't want to imply as false (e.g. Epstein didn't kill himself, members of Congress engaging in insider trading) seem to not usually be described using the specific phrase "conspiracy theory" - even when that's what they are.

I get the derogatory nature of the term, but both of your examples include groups of people keeping information from the rest of us. I'm curious if you have an example of a derogatory conspiracy theory that doesn't have a literal conspiracy in it.

My point was that the above example was called a conspiracy theory because it was against the norm, not merely because it was a conspiracy, because there are conspiracies that aren't called that because of the connotations of the term. I'm not saying that the term describes non-conspiracies.

Re: Five things we still don’t know about water

#102

Post by nawgz » Thu, Oct 21, 2021, 2:04 AM UTC

beecafe wrote: post #98

nawgz wrote: post #58

Earlier quoted context omitted.

Thanks for the comment. Thinking out loud, for prions is not the requirement that they "[act] as a catalyst, lowering the potential energy barrier ... to the point where e.g thermal fluctuations allow it to cross that barrier" also a guarantee against this type of ice-9 "infection" scenario, because the equilibrium of the environment itself would be so impacted and be absorbing that energy and then causing unfavorabl…

It depends. Tin pest is an autocalaytic reaction that doesn't produce enough energy to destabilize its own progression. One could say the same for rust, as it flakes and is porous allowing further rusting. Or the chain reaction could proceed faster than the environmental changes destabilize it - like a nuclear chain reaction, or metastable vacuum collapse. Or it could self regulate into a steady state, like a nuclear…

All very interesting points. Appreciate the insights.

Re: Five things we still don’t know about water

#103

Post by chaps » Thu, Oct 21, 2021, 2:21 AM UTC

XorNot wrote: post #91

chaps wrote: post #44

Earlier quoted context omitted.

You're also making a pretty big claim about whether a universe makes noise if no dimension is around to articulate it.

My claim is current provable cosmology. What's yours based on?

I didn't make any claim.

Re: Five things we still don’t know about water

#104

Post by knodi123 » Thu, Oct 21, 2021, 2:38 AM UTC

XorNot wrote: post #41

knodi123 wrote: post #36

Earlier quoted context omitted.

> Time itself is supposed to have been created at that point Our space-time began at the big bang. Even decades ago, Stephen Hawking was talking about it like "Since events before the big bang can have no observational consequences, we might as well leave them out of our discussion and simply say that time began at the big bang."

No observational consequences means t=0 is zero though - if no events from before then can have carried through consequences, then they might as well have not happened - certainly no information about them can ever be recovered. You are making a very strong assertion that something did carry through - what are you basing that on?

> then they might as well have not happened

"Might as well not" is different from "Did not". That's all I, and Mr Hawking, are saying. In fact, your first sentence is literally just a paraphrase of my quote from Hawking.

> You are making a very strong assertion that something did carry through

No, I most certainly did not.

All I said is, there could have been something, or could have not been. I did not say something did happen prior to the big bang, just that it is wrong to say that it could not have.

Re: Five things we still don’t know about water

#105

Post by andreareina » Thu, Oct 21, 2021, 4:20 AM UTC

AnimalMuppet wrote: post #93

andreareina wrote: post #65

Earlier quoted context omitted.

Inflationary cosmology[1] is mostly accepted in its basic form [1] https://en.wikipedia.org/wiki/Inflation_(cosmology)

Right; that has inflation beginning after the big bang.

I think "the big bang" has a problem of changing meaning. Here's my understanding:

- Naïve extrapolation of GR backwards in time results in a singularity at a finite point in time. Call that the big bang singularity (at t = 0)

- Using current accepted theory, we're able to simulate what was going on at t > 10^-32 or so. Before this, the implied densities and temperature are beyond what our theories can handle and we're less confident about how we got to that point (with an excess of baryons, smooth distribution of energy and matter, and the other parameters that obtain in our current universe).

- Inflation is one of the favored explanations for what happened before, but it doesn't address its own cause ("what happened before inflation?"). There's a theory of "eternal inflation" (local regions that have stopped inflating surrounded by regions that are still inflating), which explains the fine-tuning problem (each region that has stopped inflating can have its own fine structure etc). This is less accepted, maybe this is what you're thinking of?

- There's a push to redefine "the big bang" as all the stuff we can explain with current physics, i.e. as starting after inflation (but still using t=0 at the big bang singularity everyone's pretty sure doesn't actually exist). Or maybe it's been like that for a while and it's just pop science that perpetuates the big bang = singularity idea. Like how relativistic mass has fallen out of favor as a concept.

Re: Five things we still don’t know about water

#106

Post by heurisko » Thu, Oct 21, 2021, 5:35 AM UTC

betenoire wrote: post #100

heurisko wrote: post #82

Earlier quoted context omitted.

> If it is man-made, and they are keeping that from us, then it is a conspiracy. Therefore, conspiracy theory. No, it's the theory that it is a conspiracy, or more likely, a cover-up. (As I doubt there was a conspiracy to release the virus). "Conspiracy theory" has a specific negative connotation, and has "specific characteristics ... such as an opposition [to those] who are qualified to evaluate its accuracy." [1] […

Literally the first line from wikipedia is: > A conspiracy theory is an explanation for an event or situation that invokes a conspiracy

You've missed the rest of the sentence.

> A conspiracy theory is an explanation for an event or situation that invokes a conspiracy by sinister and powerful groups, often political in motivation,[3][4] when other explanations are more probable.[5][6]

And the distinction is clearly drawn.

> A conspiracy theory is not the same as a conspiracy

Re: Five things we still don’t know about water

#107

Post by vurpo » Thu, Oct 21, 2021, 8:32 AM UTC

feoren wrote: post #31

ncmncm wrote: post #22

Earlier quoted context omitted.

I love articles like this. Different branches of science have different relationships with their unknowns. Cosmologists will forever revile anybody who mentions something they don't know, if it conflicts with something they like to think they do know. But biologists are always eager to talk about things nobody knows about biology. The public would be much better served by carefully curated lists of what doesn't fit,…

> inflation necessarily predates big bang A tangent, but how can anything pre -date the big bang? Time itself is supposed to have been created at that point. Did you mean inflation necessarily follows a big bang?

It's not known that there was a single point in time that was the start of our universe. Our current models can pretty reliably calculate the history of the universe back to a specific point, which would be 10^-32 seconds after this big bang point in time, but those models don't work earlier than that.

You could do some extrapolation on the expansion of the universe and just say that yes, there was a point zero, 10^-32 seconds before the earliest point in time that our models can understand, and that's where everything started from a singularity. But then we are still left with a short period of time at the start, where some physics happened that we don't have a working model for.

So since an extrapolated expansion of the universe from a singularity doesn't work in our currently understood models (at least not in the very earliest part of that timeline), is it not then plausible that something other than that expansion from a singularity could have happened during this early unknown period of time?

Re: Five things we still don’t know about water

#108

Post by ghostbrainalpha » Thu, Oct 21, 2021, 2:50 PM UTC

dluan wrote: post #27

Most biological perspectives think that water behaves a certain way, which is like bulk water, when in fact at certain scales it behaves very differently, especially at interfaces and surfaces. For example, it's possible to draw flow across a charged surface where you can use it to effectively purify or separate water from things floating in it. This is useful when trying to filter out baddies like viruses and bacter…

I bet when you told people about your work, you had some actual loonies get reaaal excited to.

There is something about water that tickles the imagination in a way conductive to spiritual/magical thinking. When I read in an Ian Banks novel that Water would form ice under sufficient pressure from gravity regardless of temperature, making hot ice possible....