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Physicists Nail Down the ‘Magic Number’ That Shapes the Universe
- mojomark 6y agoTLDR: 42. (Kidding, it's apparently 1/137, but wouldn't it've been cool)
- sigzero 6y agolol...I was going to post 42.
- mrjaeger 6y agoYes but! (1 + 1) * (7 * 3) = 42 =O
- yourapostasy 6y agoLOL! I first read that as: (1 + 1) * (3 * 7) = 42 =O, guffawing because it follows the sequence of digits of the rational number 1/137 expressing the real fine structure constant.
- sli 6y ago1/137 is just 42 in a different base.
- charlieflowers 6y agoAt this moment the HN submission has 42 upvotes.
- isaacimagine 6y agoSummary: the 'Magic Number', i.e. the fine structure constant, α, which has been known to be about 1/137, has been measured more accurately. From the article: > α = 1/137.03599920611. (The last two digits are uncertain.) Implications: this constant underpins much of why the universe is the way it is. A tiny bit higher or lower would result in drastically different universes. Measuring it more precisely allows scientists to make more accurate predictions and hence rule out / refine potential models of our universe.
- bryanrasmussen 6y agocan you recommend in depth reading material on what would happen if the number were higher or lower?
- vlovich123 6y agoIt's in the article, no? > The constant is everywhere because it characterizes the strength of the electromagnetic force affecting charged particles such as electrons and protons
- bryanrasmussen 6y agowell for example when it says " Physicists have argued that if it were something like 1/138, stars would not be able to create carbon, and life as we know it wouldn’t exist." I might like to read more conjecture as to what would exist if it were 1/138 and so forth.
- sbdmmg 6y agoFrom [1] (links therein might be more in-depth) "stable matter, and therefore life and intelligent beings, could not exist if its value were much different. For instance, were α to change by 4%, stellar fusion would not produce carbon, so that carbon-based life would be impossible. If α were greater than 0.1, stellar fusion would be impossible, and no place in the universe would be warm enough for life as we know it." [1] https://en.wikipedia.org/wiki/Fine-structure_constant#Anthropic_explanation https://en.wikipedia.org/wiki/Fine-structure_constant#Anthro...
- Dylan16807 6y ago> For instance, were α to change by 4%, stellar fusion would not produce carbon, so that carbon-based life would be impossible. If it were to change by 4% in which direction? > If α were greater than 0.1 Considering it's .007 that's a ridiculously huge change. And I can't access the source article. So thanks for trying but that's not very helpful.
- JKCalhoun 6y agoOne takeaway: an apparently friendly rivalry between Paris and Berkeley physics. It is one of the things I like best about science.
- bori5 6y ago“ Table 1 of the new paper is an “error budget” listing 16 sources of error and uncertainty that affect the final measurement. These include gravity and the Coriolis force created by Earth’s rotation — both painstakingly quantified and compensated for. ” That is dope!
- rriepe 6y agoDid I read that right? They got the new number by measuring superpositional differences between an atom and... itself?
- rho4 6y ago"it differs depending on whether it’s measured in meters per second or miles per hour." Wait what?
- xyzzyz 6y agoSpeed of light is roughly 186 000 miles per second, and roughly 300 000 kilometers per second, and as it turns out, 186 000 is very much different from 300 000. The beauty of fine structure constant is that it comes out to be the same numerical value regardless of what units you choose for your measurement.
- Ragib_Zaman 6y agoThe speed of light has units. The fine structure constant is a dimensionless quantity, like pi.
- Koshkin 6y agoIn special relativity and electrodynamics c is sometimes used as a dimensionless constant (equal to 1).
- Ragib_Zaman 6y agoIn those subjects they choose different units so that the speed of light is 1 of that unit, but it still has that unit associated to it. So it is not dimensionless.
- Koshkin 6y agoThe reason it is indeed left dimensionless is that in formulas it is impossible to keep track of the dimension of an implied factor that is equal to 1. In d = t, therefore, distance and time are actually measured in the same units (usually of time).
- heycosmo 6y agoOn a related note, I highly recommend Sean Carroll's series of videos: The Biggest Ideas in the Universe [0]. The fine structure constant comes up in the 10th video on Interactions [1]. [0] https://www.youtube.com/playlist?list=PLrxfgDEc2NxZJcWcrxH3jyjUUrJlnoyzX https://www.youtube.com/playlist?list=PLrxfgDEc2NxZJcWcrxH3j... [1] https://www.youtube.com/watch?v=PaRGj5Phpm0 https://www.youtube.com/watch?v=PaRGj5Phpm0
- optimalsolver 6y agoI can now tell an article is from Quanta from the title alone.
- NetOpWibby 6y agoSo it’s NOT 42?
- Koshkin 6y agoSure, ~0x42 (modulo something) may well be a fixed-point representation of 1/137, but the margins of the book I am trying to read are too small for me to check this...
- NetOpWibby 6y ago...nobody liked Hitchhiker's Guide to the Galaxy? Yeesh, what a serious bunch.
- leonardoeloy 6y agoSays the same scientists who cannot explain why we yawn when we see other people yawning...
- SummerlyMars 6y agoWhy would physicists investigate that?
- ycreader 6y ago"Instead, the measurements match beautifully, largely ruling out some proposals for new particles" from what I understand this is some kind of Occam's razor argument saying that we don't need anything more in the standard model to explain the measurements but is this only qualitatively reasoning or does it actually gives some quantitative constrains to the possibility of new particles? I mean some particles have been predicted before being discovered (the Higgs and neutrinos I have read but there must be more) in those cases have the physicists actually gone and calculated constraints to the possibilities of that particle existing depending on the measurement of the fine structure constant?