Physicists Hunt for the Big Bang’s Triangles
quantamagazine.org
quantamagazine.org
But, are they talking about data structures in a block of storage, or what?
Are they talking about patterns on the surface (volume?) of a cellular automata?
Look at this sentence:
> "With each tick, it doubled the size of the universe, keeping nearly perfect time - until it stopped."
...What? Double the size every tick? As in... 1, 2, 4, 8, 16, 32, 64?
Don't explain it to me like I'm five. Explain it to me like I'm a developer. Please?
> Don't explain it to me like I'm five. Explain it to me like I'm a developer. Please?
It doesn't seem you need it explained to you; what you say is exactly what it means. For example, if you imagine a cube whose side increases by approximately 26% each clock tick, then each tick increases its volume by approximately (1.26)^3 = 2.00 (to 3 significant figures).
(I am not a physicist, so I may be misrepresenting, but, as far as I know, it is backwards to imply that it is somehow the ticking of a clock that causes the expansion. Rather, in the early universe one can use the logarithm of the size of the universe as a measure of time: "the universe is currently 64 times its original size, so it's log_2(64) = 6 ticks since the beginning of the universe." This is much like how the equation `E = m c^2` allows one to speak of the mass of a particle as a certain number of electron-Volts, which naïvely would be units of energy.)
I'm really surprised that Inflation got such a "foothold"... in that it's quite wobbly as a therory, AFAICT. For a kick-off it's pretty hard (impossible?) to falsify. Yes, we can all agree that something like the Big Bang happened; just by looking at the expansion, everything was obviously a lot more squished up. (Extrapolate backwards and you get 'silliness' like the Singularity... which is just a photosynthesis[1] way of saying NaN.)
[1] Shamelessly stolen from a redditor: "I like to use difficult words so people think I'm photosynthesis.".
EDIT: Honestly, I'm not a kook! Neil Turok usually has good introductory lectures for this field...
I wasn't meaning to describe my own understanding, or to endorse (or reject) the articles', only to describe what I thought was meant.
> For a kick-off it's pretty hard (impossible?) to falsify. Yes, we can all agree that something like the Big Bang happened; just by looking at the expansion, everything was obviously a lot more squished up. (Extrapolate backwards and you get 'silliness' like the Singularity... which is just a photosynthesis[1] way of saying NaN.)
Indeed, as your parenthetical points out, I think that even your second sentence might be debatable. Questions about the beginning of the universe are, necessarily, not subject to experimentation, at least not now or in the foreseeable future; so my understanding—and bear in mind, as Dave Barry would say, that I have read several books of popular physics—is that the best that we can do is to give explanations that, based on our current understanding of the current laws of physics, are compatible with the observeable consequences of the distant and (physics-ally) exotic past. Since extrapolation eventually produces results that are guaranteed mathematical nonsense, assuming that they are still valid just before they're nonsensical seems inevitably to be more an article of faith than of science in its usual sense.
P.S. Also, with folks like Max Tegmark (https://en.wikipedia.org/wiki/Max_Tegmark) not only 'out there', but at MIT, I don't think anyone need fear being labelled a kook for what he or she believes, or doesn't believe, about the origin of the universe.
P.P.S. Hello from the thread on Street-Fighting Mathematics, where we've also been chatting! :-)
Without inflation, how would you solve these?
Inflationary models make predictions about higher moments distribution of fluctations in the cosmic microwave background. These can be measured; so specific models can be falsified.
As far as the structure goes, they're talking about structures approaching literal geometric shapes visible in the large scale structure of the universe. Basically, if Lucy was in the sky, they would find diamond-shaped structures, in addition to triangles, pentagons, etc. (My poor attempt at analogy!)
In particular, I'm not involved in cosmology or string theory, so take all the following explanation as a educated guess ...
> ...What? Double the size every tick? As in... 1, 2, 4, 8, 16, 32, 64?
It's only a "friendly" way to say "exponentially", or in other words, it's only a "confusing" way to say "exponentially". There is no discrete interval clicks of a magic clock, only continuous exponential grow.
In the early moments of the universe, there was an inflation period. The universe grew very very very exponentially fast, and it became very uniform. They suspect that the small quantum fluctuations during/just-before this period caused small uniformities in the universe.
After all this time, the uniformities created the galaxies and/or clusters of galaxies. So if they measure the position and size of the galaxies/cluster they can try to classify the quantum fluctuations during the inflation. There is also similar information in the background radiation, so they want to measure it too.
Sometime, a quantum fluctuation form two particles, and one of the particles splits in two particles, so you get tree particles! They call them "triangles", I don't know why. If you assume that the energy and momentum is conserved, then the properties of the particles are related. So you can try to choose all the terns of galaxies/clusters/whatever and select only the ones that have this relation. I guess it's more difficult, because the galaxies collide, and move around other galaxies, and that king of things, so you have to do a lot of calculation, not just take the current position.
So the "triangles" are just three "interesting" features in the space, that follow some rules. Don't expect to see the three points joined by segments :), or the inner part of the triangle painted :) :).
There was a lot of energy around during the inflation period, so they expect to see some strange particles that are predicted by the superstring theory. Actually, there are many variations of the superstring theory, and they whish to eliminate a few using this data. Anyway, they still have to increase the sensibility of the experiment 1000 fold to get something useful, so don't hold tour breath.
The idea is that the properties of the objects in the triangle depend on the properties of the particles of the initial random fluctuation during the inflation. There are a lot or random variables here, so they have to find a lot of triangles and do a lot of statistic. They can predict the distribution of the triangles created by each kind of particle, and them sum with weight each distribution and compare that with what they find in the universe.
In particular, they want to see if all the triangles are explained by elemntary particles of spin 0, 1/2 and 1, or they have to include in their model also particles of spin 3/2, 2, ... Nobody have seen elementary particles of spin 3/2, 2, ... but the string theory predict that the exist. So finding them will give some experimental support for string theory, and perhaps use the details to filter some variations.
You could try to create this elementary particles with spin 3/2, 2, ... in the laboratory, but you need a very big particle accelerator, perhaps bigger than the solar system or the galaxy. So the only hope is to "find" them in some astronomical data.
I just want to repeat that I'm not involved in cosmology or string theory, so take all the explanation as a educated guess ...