2113: "Physics Suppression"

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Eebster the Great
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2113: "Physics Suppression"

Postby Eebster the Great » Tue Feb 19, 2019 12:15 am UTC

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Title text: "If physics had a mafia, I'm pretty sure the BICEP2 mess would have ended in bloodshed."

I see this attitude all over the place, that physics is monolithic and the only reason whatever crackpot theory isn't mainstream is the risk-averse bias of physicists unwilling to admit any problem with the standard model. It's super weird, because the physics literature is absolutely chock-full of fringe, speculative ideas and modifications to basic laws. It is almost the best example in science of the exact opposite of the accusation. But I guess if you aren't aware of any of that and get all your information about physics from half-remembered high school lessons, YouTube videos, blogs, and random clips of Michio Kaku interviews out of context, it could seem that way.

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Re: 2113: "Physics Suppression"

Postby qvxb » Tue Feb 19, 2019 12:46 am UTC

Don't ask me about my theory. It did not fall off the back of a truck. I"ll only tell it to the biologists. They don't have souls.

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Re: 2113: "Physics Suppression"

Postby Pfhorrest » Tue Feb 19, 2019 1:07 am UTC

I've always had the exact opposite of this guy's experience. All my life I come up with some kind of hair-brained crackpot half-baked idea I know I could never do proper scientific justice to and so I let it sit as just some crazy idea I have that's at best a neat thing for idle conversation... and then a few years later some professional academic paper comes along proposing "exactly that" (to the best of my ability to ascertain, but properly fleshed out with, you know, actual science work). Entropic gravity is one example that comes to mind.

I joke sometimes that I have a very subtle super power: if I say "someone should really invent..." or "maybe it really works like...", fairly soon someone invents that or researchers find that things really do work like that.
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Re: 2113: "Physics Suppression"

Postby rmsgrey » Tue Feb 19, 2019 1:49 am UTC

Yes, physicists are suppressing the theory, just like mathematicians suppress the theory that the alphabet only actually has 24 letters...

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Re: 2113: "Physics Suppression"

Postby cellocgw » Tue Feb 19, 2019 12:19 pm UTC

rmsgrey wrote:Yes, physicists are suppressing the theory, just like mathematicians suppress the theory that the alphabet only actually has 24 letters...


Actually (I know, I know) the mathematicians don't care how many letters; they're just suppressing the theory that the alphabet is a noncommutative ring.

Physicists suppress theories by tying them up with multidmensional String
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Re: 2113: "Physics Suppression"

Postby solune » Tue Feb 19, 2019 5:12 pm UTC

I want to register my agreement with Randall re: the dark energy people. I was pretty happy about the Big Crunch, and the Big Rip was cool too, but the Big Freeze is really an annoying result. I want the universe to just keep going, you know ?

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Re: 2113: "Physics Suppression"

Postby Jorpho » Tue Feb 19, 2019 5:24 pm UTC

Some of the popular science sites seem to suggest the only thing you need for a physics theory to gain traction is a catchy tagline. "Physicists learn that spacetime is gluten-free!" or something.

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Re: 2113: "Physics Suppression"

Postby ijuin » Tue Feb 19, 2019 6:38 pm UTC

solune wrote:I want to register my agreement with Randall re: the dark energy people. I was pretty happy about the Big Crunch, and the Big Rip was cool too, but the Big Freeze is really an annoying result. I want the universe to just keep going, you know ?


The funny thing is that the Big Freeze is the scenario that lets life continue to exist the longest—a technological civilization can last until the very protons decay a trillion trillion years hence, whereas a Big Crunch or Big Rip scenario tends to have the universe end long before then.

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Re: 2113: "Physics Suppression"

Postby SDK » Tue Feb 19, 2019 7:03 pm UTC

ijuin wrote:The funny thing is that the Big Freeze is the scenario that lets life continue to exist the longest—a technological civilization can last until the very protons decay a trillion trillion years hence, whereas a Big Crunch or Big Rip scenario tends to have the universe end long before then.

But then people can't fool themselves into thinking of the universe as a cycle of creation and destruction, as if somehow that might give life more meaning.
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Re: 2113: "Physics Suppression"

Postby Eebster the Great » Wed Feb 20, 2019 2:15 am UTC

It's a nice fact to be true if you believe in eternal recurrence, I guess, though you can always find other ways for that hypothesis to be true if you really want.

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Re: 2113: "Physics Suppression"

Postby Soupspoon » Wed Feb 20, 2019 3:47 am UTC

Back in the '80s I was in a lecture on astronomical matters and the straw poll by the person taking it found the attendees to be largely 'in favour of' the Big Bounce model (or whichever name and version of cyclic Bang-Crunch-Bang-… was presented at the time). Apparently to the surprise of the lecturer, as usually the audiences would favour eternal expansion and heat-death (this was before much talk of things that lead to a Big Rip, so wasn't an option I recall being offered) as their instinctive prediction on this matter.

(That was my idea at the time, with a feeling that the mass/energy could be balanced exactly on the boundary between enough to expand forever and not enough to stop re-collapse. Knowing that this was mathematically troublesome without some 'friction' analogue, but feeling that the aesthetics of a Big Bang banging just the right proportion of mass and momentum had something to go for it. These days there's all kinds of other things, like Dark Energy, to factor in. But actually I've got another idea by now, that's at least as practically untestable as far as I know, from outside the relevent parts of the field.)

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Re: 2113: "Physics Suppression"

Postby Pfhorrest » Wed Feb 20, 2019 4:04 am UTC

Do I recall correctly that a universe expanding right along that balance point corresponds to a universe with cosmologically flat spacetime (the big crunch and big rip scenarios corresponding to positive and negative curvature respectively)? If so, that alone seems like a good reason to have supposed that it might be the case, with a flat universe seeming kind of a sensible default to suppose in absence of any evidence to the contrary (which I'm pretty sure we have now). IIRC until 1997(?) when the accelerating expansion of the universe was discovered, all evidence otherwise had suggested that the universe really was just about flat. It does seem something of a suspicious coincidence to me that we (as a species) should be so lucky to exist at just that moment in time (cosmologically speaking, e.g. the holocene, not the 20th/21st century) when the negative curvature / accelerating expansion should happen to just barely become noticeable, though I'm not sure what exactly we should suspect from that coincidence.
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Re: 2113: "Physics Suppression"

Postby ijuin » Wed Feb 20, 2019 5:33 am UTC

Well, there are some constraints on when humanity could have arisen in the cosmic timeline. The Solar System formed when the universe was about nine billion years old, and it probably could not have produced an Earth-like planet if it had formed billions of years earlier, since there would not be sufficient heavy elements available.

Meanwhile, the time when the universe’s accelerated expansion started to diverge significantly from a no-dark-energy model was also about five billion years ago. This implies that humans probably could not have arisen a significant amount of time before dark energy became noticeable.

Personally, the thing that I find most fascinating about the Big Rip model is that its end state looks extremely similar to the cosmic inflationary state in the Big Bang. Perhaps, then, the start of our Big Bang is the Big Rip of the previous universe?

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Re: 2113: "Physics Suppression"

Postby Pfhorrest » Wed Feb 20, 2019 7:44 am UTC

That is the basic idea behind eternal inflation. Inflation wasn't just a weird thing that happened in the early universe, it's a thing that's always happening, to various degrees, across the "multiverse", if we count areas separated by inflation from ever communicating with each other as "separate universes".

I feel like either I'm missing something (some violation of the 1st law of thermodynamics maybe? which I recall hearing does not hold on cosmological scales anyway) or that wouldn't really be eternal though, as each wave of sub-universes inflated apart from each other out of a previous universe would get smaller and smaller and eventually you'd just have universes of isolated protons until those get ripped apart too and then you're done forever.
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Re: 2113: "Physics Suppression"

Postby solune » Wed Feb 20, 2019 9:47 am UTC

Pfhorrest wrote:...each wave of sub-universes inflated apart from each other out of a previous universe would get smaller and smaller and eventually you'd just have universes of isolated protons until those get ripped apart too and then you're done forever.


My understanding of the virtual particle pairs mechanism is that you never have universes with a single particle in them. Whenever you have a piece of space-time, some pairs of particles will develop in it, and if the space inflates fast enough the particles can get away from each other before they can recombine.

The preceding is a bad regurgitation of Lawrence Krauss' theory

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Re: 2113: "Physics Suppression"

Postby jonhaug » Wed Feb 20, 2019 10:26 am UTC

Pfhorrest wrote:I've always had the exact opposite of this guy's experience. All my life I come up with some kind of hair-brained crackpot half-baked idea I know I could never do proper scientific justice to and so I let it sit as just some crazy idea I have that's at best a neat thing for idle conversation... and then a few years later some professional academic paper comes along proposing "exactly that" (to the best of my ability to ascertain, but properly fleshed out with, you know, actual science work). Entropic gravity is one example that comes to mind.

I joke sometimes that I have a very subtle super power: if I say "someone should really invent..." or "maybe it really works like...", fairly soon someone invents that or researchers find that things really do work like that.


I am impressed! Can you explain your thinking on the subject of entropic gravity? I mean, 100 years ago, looking at a world map, it is understandable that someone said "South America's east coast seems to fit with Africa's west coast. Maybe they were connected some time in the past?", but entropic gravity? Did you look at the sky and said, "Those distant galaxies moves a bit too fast from us, don't they?"

/Jon

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Re: 2113: "Physics Suppression"

Postby sonar1313 » Wed Feb 20, 2019 2:43 pm UTC

Pfhorrest wrote:I've always had the exact opposite of this guy's experience. All my life I come up with some kind of hair-brained crackpot half-baked idea I know I could never do proper scientific justice to and so I let it sit as just some crazy idea I have that's at best a neat thing for idle conversation... and then a few years later some professional academic paper comes along proposing "exactly that" (to the best of my ability to ascertain, but properly fleshed out with, you know, actual science work). Entropic gravity is one example that comes to mind.

I joke sometimes that I have a very subtle super power: if I say "someone should really invent..." or "maybe it really works like...", fairly soon someone invents that or researchers find that things really do work like that.

Sooooo......what's your opinion on cold fusion? Shouldn't someone invent that? Someone should really invent that, right?

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Re: 2113: "Physics Suppression"

Postby Pfhorrest » Wed Feb 20, 2019 6:29 pm UTC

jonhaug wrote:I am impressed! Can you explain your thinking on the subject of entropic gravity? I mean, 100 years ago, looking at a world map, it is understandable that someone said "South America's east coast seems to fit with Africa's west coast. Maybe they were connected some time in the past?", but entropic gravity? Did you look at the sky and said, "Those distant galaxies moves a bit too fast from us, don't they?"

It was about ten years ago, and my own original ideas have probably been hopelessly muddled up with things I've read about the actual research in relation to that by now, so it's hard to remember what exactly was going on in my head back then.

I'm pretty sure my line of thought started with thinking about the nature of time as an anisometry in the phase-space of the universe, basically a gradient of possible configurations of energy from less-entropic "hilltops" to more-entropic "plains", with "downhill" in that metaphor corresponding to "toward the future" and the Big Bang corresponding to the nearest "hilltop". A step from one place in configuration space to the nearest other place in configuration space is the smallest moment of time, and the smallest possible change. From there I think I was thinking about the idea that basically everything that happens, happens precisely because it increases entropy: all changes are essentially random, but changes to more-likely states, states that are more bountiful in the configuration space, are the kinds that tend to happen more often, so after many steps in random directions in the configuration space, you're going to find yourself moving on average in a "downhill"/more-entropic/future-ward direction, and that's precisely where our concept of "future" comes from: the kinds of states that things tend to evolve toward.

I think from there I was thinking about how something like gravity could be explained by this, and I think that that went something along the lines of thinking that there were fewer degrees of freedom for a system with less space to move around in, so it would be entropically favorable for things to be closer together... this is the area where my memory of my old thoughts get fuzzy. I think there might have also been some thoughts in there along the lines of gravity being basically a side-effect of time dilation, things curving towards areas with slower time the way rolling objects will curve onto a surface with higher friction (or light will bend into a medium with a higher index of refraction) and that since in the above model of time a single change of state corresponds to a moment of time, whenever two particles interact they have to spend time that they might otherwise have spent moving on that interaction instead, and since interactions increase in strength as distance decreases, two objects will have to move through space more slowly the closer they get to each other, creating an apparent time dilation, that then creates a curve in the direction of motion, that is gravity.

Like I said though it was a long time ago, and I'm just trying to dredge up whatever scraps of old thoughts I can remember through my present-day stress-addled brain that isn't sharp enough to properly vet how much sense any of this probably doesn't make. But one way or another I had recently been thinking "maybe gravity is caused by entropy" right before Verlinde published his paper on the topic.
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Re: 2113: "Physics Suppression"

Postby rmsgrey » Thu Feb 21, 2019 1:52 am UTC

Pfhorrest wrote:That is the basic idea behind eternal inflation. Inflation wasn't just a weird thing that happened in the early universe, it's a thing that's always happening, to various degrees, across the "multiverse", if we count areas separated by inflation from ever communicating with each other as "separate universes".

I feel like either I'm missing something (some violation of the 1st law of thermodynamics maybe? which I recall hearing does not hold on cosmological scales anyway) or that wouldn't really be eternal though, as each wave of sub-universes inflated apart from each other out of a previous universe would get smaller and smaller and eventually you'd just have universes of isolated protons until those get ripped apart too and then you're done forever.


If you have the right density of matter in an isolated region, then the mass cancels exactly with the gravitational potential energy, and you end up with a region with no net energy, so there's not necessarily a violation of conservation of energy.

It does seem to be a case of constantly getting something from nothing, but it could just be constantly splitting nothing, and then adding more nothing to be split in turn...

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Re: 2113: "Physics Suppression"

Postby Pfhorrest » Thu Feb 21, 2019 2:27 am UTC

I'm not sure I follow there. Say for a toy example you have a universe of 16 hydrogen atoms, arranged in such a fashion as you describe. Inflation separates them into two "universes" of 8 hydrogen atoms each, and then separates those into four "universes" of 4 hydrogen atoms each, and then eight of 2 and sixteen of 1 each and then I guess the atoms get ripped apart and so do the nucleons? Is there some process I'm missing where the inflation adds another 8 hydrogen atoms (or an equivalent amount of energy that can get turned into matter later) to each of the two halves of the original 16-atom universe that it separated, so you keep on having 16-atom "universes" being inflated apart from each other instead of smaller and smaller "universes" until there's nothing left to separate?

The prospect of that reminds me of why you can't separate quarks, and now I'm wondering if the process of inflating-apart nucleons wouldn't just boil down to precisely that? To inflate a proton apart you have to add enough energy that it spontaneously generates new quarks to pair off with the ones you split the proton into. So the energy inflation imparts to pry apart one universe into two adds enough energy to each that each ends up as energetic (and hence massive) as the original one?
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Re: 2113: "Physics Suppression"

Postby Tub » Thu Feb 21, 2019 12:03 pm UTC

Ignore hydrogen for a moment, because nucleosynthesis didn't happen until after inflation ended.

What's important is that you can take one empty volume of space and stretch it into two empty volumes of space. As space is never "empty", you've now created both new space and new energy, for free.
Some people will tell you that it's possible because the created energy cancels out with negative gravitational potential energy or something, others will insist that the metric expansion of space simply does not conserve energy.

The rate of expansion of empty space depends on the vacuum energy. The theory of Inflation says that there's a second vacuum state with much higher energy, causing really fast expansion. Regions of space will eventually decay into the low energy vacuum state we know, producing a lot of nice things (including hydrogen) from the excess energy.

What I think you (and ijuin) are misunderstanding is that eternal inflation does not mean that the part of the universe we currently live in will re-join with the inflating part, or start inflating again, or anything. It keeps expanding at an accelerated rate due to the vacuum energy we have, but I don't see how it would get back to the higher vacuum state of inflation. Unless there's an infinite staircase of false vacuums (and I haven't heard anyone seriously suggesting so), our universe will just cool off. As we can't produce new hydrogen at current energies, hydrogen density diminishes. Energy density is asymptotically constant.

Eternal inflation just means that the parts of the universe that are currently inflating will create new inflating volumes of space at a quicker rate than they lose inflating volumes due to decay, so the volume of space that is inflating at any given time does not decrease. Hence, inflation never stops.

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Re: 2113: "Physics Suppression"

Postby Eebster the Great » Thu Feb 21, 2019 8:26 pm UTC

Incidentally, there is a scenario of increasing cosmological "constant" in which all particles really do get ripped away from each other into their own isolated observable universes. It's called the Big Rip. It's not a super plausible end to the universe at this point, but it's difficult to rule out with experiment.

I don't know what happens in the Big Rip scenario when the observable universe becomes smaller than a proton. My guess is you just get isolated quarks with some complicated dressing.

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Re: 2113: "Physics Suppression"

Postby da Doctah » Fri Feb 22, 2019 9:58 am UTC

Pfhorrest wrote:I've always had the exact opposite of this guy's experience. All my life I come up with some kind of hair-brained crackpot half-baked idea I know I could never do proper scientific justice to and so I let it sit as just some crazy idea I have that's at best a neat thing for idle conversation... and then a few years later some professional academic paper comes along proposing "exactly that" (to the best of my ability to ascertain, but properly fleshed out with, you know, actual science work). Entropic gravity is one example that comes to mind.

I joke sometimes that I have a very subtle super power: if I say "someone should really invent..." or "maybe it really works like...", fairly soon someone invents that or researchers find that things really do work like that.


That's how I came up with Facebook, years before Zuckerberg or the Winklevosses or whoever gets the credit these days. It was after observing that every time a bunch of my older female relatives got together, the first thing that happened was they hauled out this massive address books full of strikeouts and post-it notes and proceeded to synchronize: "I still have Betty living in Salt Lake City", "Oh, she's in El Paso now", "Do you know Eugene's current phone number?", "No, but Darlene's kids have moved out on their own now", etc....

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Re: 2113: "Physics Suppression"

Postby Soupspoon » Fri Feb 22, 2019 11:21 am UTC

(I had an idea very very similar to Minecraft, except with varied polyhedra rather than voxels* about 30 years ago. Looks like I missed out on that market.)

* Makes all the difference. It makes what was a hard rendering problem much harder, and these days it would make it awkward rather than simplicity itself.


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