Everything posted by joigus
-
Today I Learned
-Today I've learnt about: Einzel lenses and viral load in aerosols. Indebted to: Swansont -Today I've learnt about: colour-entangled W states Indebted to: Studiot -Today I've learnt more details about: quaternary-structure protein dymers and palindromic character of RNA sequences Indebted to: Dagl1 and CharonY -Today I've learnt about: Intricacies related to atmospheric CO_2 absorption by weathering at the Himalayas Indebted to: Area54 and Studiot -Today I've learnt about: phenomenological/heuristic aspects of cosmology in general Indebted to: Mordred -Today I've learnt about: geons Indebted to Strange There's quite a bunch of 'todays' there. And I'm still learning. And counting...
-
Only 10% of the Nobel prize winners are atheist ?
Easy. If what the survey says is actually true --see below: Analogy --not to be taken literally: Go to a prison and ask all convicts for murder crimes whether they're guilty or not. You end up with a list of: 10 % say they did; 65 % say didn't and 25 % don't remember. Conclusion: Only 10 % of convicts for murder crimes actually did commit a crime. Explanation: In the words of Daniel Dennett; American Philosopher and scientist, outstanding at exposing many religious (and other) logical fallacies IMO, "they believe in believing in God." I.e.: They live in a social environment in which it would be far more costly for them to declare themselves atheists than to keep on pretending. Dennett, e.g., takes no prisoners when it comes to theologians. They all fall --willingly or not-- in the use/mention fallacy: "A history of God," "God in our society," etc. Religion is absolutely rife with fallacies, half-truths, and conveniently spun arguments and data. Besides, as iNow says, . Excellent point.
-
Blowing hot and cold
It never crossed my mind. Well, it did, but it was a virtual process.
-
The Official "Introduce Yourself" Thread
Forgot to say hello. I'm Joss, I teach Physics, Maths, Chemistry and English @ some academy in Spain. They sometimes make me teach Bio and Spanish, because they somehow assume I must know everything. I'm a theoretical physicist. My alter ego is Sisyphus. PD: I love Yogi Berra quotes
-
Blowing hot and cold
Feynman Lectures on Physics, volume 1, chapter 1, Section 1-3. Atomic Motion. Go to your local library and start reading Feynman now. Then start mimicking Feynman in whatever way you can without giving up your principles, and maybe buy a pair of bongos. Just joking. But the key word in all of this is: Feynman.
-
Cosmological Principle
I see no significant mistake in the enunciation of the principle. I wouldn't include time to it though, nor do I know of any formulation that does. Another hopefully useful observation is that isotropy everywhere implies homogeneity, which is kind of more economic to me, but not really a big deal. As to current limits to its application/validity/solidity, I hope you find interesting my comments below: The whole issue of the universe being homogeneous and isotropic at 'large' scales is, in my opinion, a very suspect hypothesis. It looks kind of reasonable, though, and allows you to gain access to the big picture of what goes on. But 1) from the theoretical perspective we do know that quantum field theory (QFT), when combined with the general theory of relativity (GTR) in inflationary models, predicts a universe that is more like a fractal, meaning a scale-independent series of embedded structures that may look clustering depending on what scale you look at it. And 2) from the observational point of view, the universe does seem to display huge voids in its structure, very strongly resembling that fractal that QFT+GTR predicts. It's more like the caustics in a swimming pool in 3D (this is a numerical simulation): About isotropy, a very recent piece of news from the experimental front is this: https://phys.org/news/2020-04-laws-nature-downright-weird-constant.html?fbclid=IwAR3_NdXDNfcNU05E8khtN1pnshucr-gr7KoJO5OTh6OAuDDX19Z5yUBPD_c The headline reads, "New findings suggest laws of nature 'downright weird,' not as constant as previously thought". UNSW --Sidney-- professor John Webb: "We found a hint that that number of the fine structure constant was different in certain regions of the universe. Not just as a function of time, but actually also in direction in the universe, which is really quite odd if it's correct... but that's what we found." If that's true, not only the universe wouldn't be homogeneous; it wouldn't be isotropic either, and at the deepest level, because what's different is the electromagnetic coupling constant itself. Now this would really be amazing and we should take it with a grain of salt. The statement that the universe is homogeneous in time is tantamount to saying that it looked pretty much the same in the past than now or in the future. It was obviously not the same in the past, as it looked like a singularity, then opaque to radiation and neutrinos (plasma), then radiation dominated, then matter dominated, and today it's considered to be dark-energy dominated. So it doesn't really look like it's going to be the same in the future, as it will exponentially expand.
-
Corona virus general questions mega thread
This may be a silly question, but just in case. Can someone tell me if there is the possibility of using RNA-splicing endonucleases like the ones referred to at, https://www.ncbi.nlm.nih.gov/pubmed/18217203 to target specific sections of a known virus in order to deactivate it inside the cell in a similar way that restriction enzymes in bacteria function against their bacteriophages? Maybe by designing or selecting them to look for very specific viral sequences but long enough so that they have a very low repeat probability? Or maybe by methylating the sensitive areas in the self RNA? I don't even remember if RNA is susceptible to methylation, which DNA is. Or maybe both? Is that even possible? Or maybe too out there. I'm not even sure this is the proper place to pose this question. I'm sorry if that's the case. Thanks a lot in advance.