Realitycheck Posted June 22, 2011 Share Posted June 22, 2011 http://www.physorg.com/news/2011-06-baby-star-blasts-jets-space.html Link to comment Share on other sites More sharing options...
CaptainPanic Posted June 23, 2011 Share Posted June 23, 2011 Before I start ranting, I'd like to say that it's actually an interesting article. I liked to read it. But it contains 1 mistake. from the article: In a process that almost defies adjectives and analogies, each jet of water is the equivalent of a hundred million times the water flowing through the Amazon River every second and the speed of the jet is the equivalent of 80 times the muzzle velocity of an AK-47 assault rifle. (emphasis mine) I hate it when scientific writers get this wrong. A flow is already volume/time, so the extra addition of 'every second' is just wrong. The flow of water in the star is a hundred million times more than that of the Amazon. Period. Unless they mean to say that the flow of water in the jets (which, as is later explained could last 1 year) is equal to 100*10^6 times that of the amazon per second. If you put a 'per time' on both sides of the equation (per second and per year), it has the correct dimensions again. But that would result in the jets being only 100*10^6 / (365*24*3600) = 3.2 times larger than the flow of the Amazon, which I really doubt. This happens most often with energy vs. power. I have lost count of the times I have seen articles say stuff like 'power per second'. People should do a dimensional analysis. Or just not write. (And no, this is not pedantic, you also would not accept it if I mixed up a velocity and an acceleration of a car? That's the same thing: one additional 'per second' changes a velocity into an acceleration). Link to comment Share on other sites More sharing options...
John Cuthber Posted June 23, 2011 Share Posted June 23, 2011 OK, outbreak of serious pedantry warning. They didn't say "per second" they said "every second", and they are probably right. It was true the second they wrote it, it was true during the second when you read it and it will be true at the second when you read this reply. It's redundant, and potentially confusing, but it's not wrong (at least until the flow changes). It's like saying "2+2= 4 every day". Now, would you like to get into a discussion of the muddling of speed and velocity? (At least they say it's "the equivalent") How about a clear definition of what "In a process that almost defies adjectives and analogies," actually means in a context where the next thing they do is add some analogies? Link to comment Share on other sites More sharing options...
CaptainPanic Posted June 23, 2011 Share Posted June 23, 2011 John Cuthber, Next time, I promise to drink another coffee before posting my 1st post of the day here You have a fair point, and I should probably have searched for another article for such a rant. Link to comment Share on other sites More sharing options...
mississippichem Posted June 23, 2011 Share Posted June 23, 2011 (edited) John Cuthber, Next time, I promise to drink another coffee before posting my 1st post of the day here You have a fair point, and I should probably have searched for another article for such a rant. I forgive you. If you are like me, your competence depends exponentially on your blood caffeine concentration. This function has a local max though, too much caffeine, and I degrade back into a babbling idiot . Edited June 23, 2011 by mississippichem Link to comment Share on other sites More sharing options...
Airbrush Posted June 23, 2011 Share Posted June 23, 2011 (edited) "...each jet of water is the equivalent of a hundred million times the water flowing through the Amazon River every second..." I agree that this is somewhat vague. I think this means that in one second the star blasts off 100 Million times the amount of water in the entire Amazon River. This is much more than one second of flow of the Amazon River. Edited June 23, 2011 by Airbrush Link to comment Share on other sites More sharing options...
Realitycheck Posted June 28, 2011 Author Share Posted June 28, 2011 (edited) Oops, I should spend more time proofreading my posts. That is absolutely unthinkable, must have been in a really big hurry. And that was copied with my Linux box. Makes no sense! Edited June 28, 2011 by Realitycheck Link to comment Share on other sites More sharing options...
CaptainPanic Posted June 28, 2011 Share Posted June 28, 2011 I forgive you. If you are like me, your competence depends exponentially on your blood caffeine concentration. This function has a local max though, too much caffeine, and I degrade back into a babbling idiot . Requires its own thread (because it's totally off topic, and because it's possibly more important than the birth of stars)... but your statement of the local max seems to fit my own experiences quite well. I wonder if there aren't multiple maximums though. I seem to have one in the morning, and another somewhere in the afternoon. However, since some people pay me to drink coffee (and afterwards work) I end up posting on the forum while not optimally caffeinated so that I can work efficiently when sufficiently caffeinated. I shall however refrain from posting without any coffee at all from now on (I hope I remember!). Link to comment Share on other sites More sharing options...
pantheory Posted July 5, 2011 Share Posted July 5, 2011 (edited) http://www.physorg.c...jets-space.html Baby stars go through stage of water creation Interesting article. I never thought of it before but it sounds like a most likely mechanism for the observed water in our solar system and the universe at large. Water would seem to assist in planet formation as would molten/ liquid bodies in general. Such liquids, many ices, and related atmospheric gasses could seemingly reduce the carom effect of proto-planets, moons, asteroids, comet-like bodies etc. upon colliding, facilitation the formation of larger entities. . Edited July 5, 2011 by pantheory Link to comment Share on other sites More sharing options...
Recommended Posts