Katie Mack, a well-known astrophysicist at North Carolina State, also took issue with the alien hype.
"The thing you have to understand is: scientists are perfectly happy to publish an outlandish idea if it has even the tiniest sliver of a chance of not being wrong," she wrote on Twitter.
"But until every other possibility has been exhausted dozen times over, even the authors probably don't believe it."
I wonder if publishing a paper like this, say, 20 years ago would've ended one's career...
- Doc
In the face of madness, rationality has no power - Xiao Wang, US historiographer, 2287 AD.
Every record...falsified, every book rewritten...every statue...has been renamed or torn down, every date...altered...the process is continuing...minute by minute. History has stopped. Nothing exists except an endless present in which the Ideology is always right.
Katie Mack, a well-known astrophysicist at North Carolina State, also took issue with the alien hype.
"The thing you have to understand is: scientists are perfectly happy to publish an outlandish idea if it has even the tiniest sliver of a chance of not being wrong," she wrote on Twitter.
"But until every other possibility has been exhausted dozen times over, even the authors probably don't believe it."
I wonder if publishing a paper like this, say, 20 years ago would've ended one's career...
- Doc
Not as much as you might think. Sagan published pieces seriously considering extraterrestrial life, including artifacts being found throughout the solar system.
Gunnar wrote:I calculated that a rotation period of 4 minutes would be enough to create an artificial gravity due to centrifugal force of about 0.7 gees near the outer perimeter of a cylinder 20 kilometers in diameter, as described in the novel.
Yup, your calculation of the acceleration towards the centre of rotation of an object in a uniform circular motion with a radius of 10,000 m and a period of 4 minutes = 240 s is correct. It's about 6.85 m/s^2.
But do me a favor - please don't talk about a centrifugal force (which means a force directed AWAY from the centre of rotation). The person walking round the inside of the circumference of the cylinder with their head towards the centre experiences a centripetal force TOWARDS the centre exerted on their feet by the inner surface of the cylinder. That is the only way that they can keep accelerating towards the centre, which is what they have to do to keep moving in a circle. (Remember Newton's 2nd law). If the cylinder suddenly evaporated and thus ceased to exert that centripetal force on them, they would simply continue moving at constant speed in a straight line tangential to the (vanished) cylinder from the point where they were when it disappeared. (Newton's 1st law).
Physics is much easier and simpler if you think about it logically and consistently. It's also more beautiful that way ...
Zadok: I did not have a faith crisis. I discovered that the Church was having a truth crisis. Maksutov: That's the problem with this supernatural stuff, it doesn't really solve anything. It's a placeholder for ignorance.
Katie Mack, a well-known astrophysicist at North Carolina State, also took issue with the alien hype.
"The thing you have to understand is: scientists are perfectly happy to publish an outlandish idea if it has even the tiniest sliver of a chance of not being wrong," she wrote on Twitter.
"But until every other possibility has been exhausted dozen times over, even the authors probably don't believe it."
I wonder if publishing a paper like this, say, 20 years ago would've ended one's career...
- Doc
Once DT realizes this applies to climate change as well his head will explode.
Chap wrote:But do me a favor - please don't talk about a centrifugal force (which means a force directed AWAY from the centre of rotation). The person walking round the inside of the circumference of the cylinder with their head towards the centre experiences a centripetal force TOWARDS the centre exerted on their feet by the inner surface of the cylinder. That is the only way that they can keep accelerating towards the centre, which is what they have to do to keep moving in a circle. (Remember Newton's 2nd law). If the cylinder suddenly evaporated and thus ceased to exert that centripetal force on them, they would simply continue moving at constant speed in a straight line tangential to the (vanished) cylinder from the point where they were when it disappeared. (Newton's 1st law).
Physics is much easier and simpler if you think about it logically and consistently. It's also more beautiful that way ...
Your point is well taken! I do realize that centripetal force is what the inhabitants of such a rotating cylinder actually experience, and that centrifugal force is actually an imaginary force. I vacillated over whether I should use the word "centripetal" rather than "centrifugal" for several minutes before submitting my post, but as so many more people are familiar with the more commonly used (though imaginary) "centrifugal force" in connection with the concept of artificial gravity, I figured (perhaps wrongly) that more readers would understand what I meant if used the more familiar term.
No precept or claim is more likely to be false than one that can only be supported by invoking the claim of Divine authority for it--no matter who or what claims such authority.
“If you make people think they're thinking, they'll love you; but if you really make them think, they'll hate you.”
― Harlan Ellison
Doctor Steuss wrote:Therefore, it's an alien probe with 300-900 micron solar sail (that hasn’t been observed) that has managed to remain intact through lord knows how many light years, and we know it’s intact because the theory says it is. Meh.
An interstellar kite propelled by solar winds. Hey, people have believed in stranger things.
MeDotOrg wrote:We need to build a wall around the solar system. Keep those effing alien probes isolated in the slums of the central galaxy.
Excellent point. For all we know, those Moties are up to no good!
The important takeaway about light is not that it's the fastest thing in the universe, but that there is a speed limit in the universe. The fact that we have a speed limit defines the universe. If something were infinitely fast it could exist at 2 places simultaneously (please don't go all quantum physics-y on me). Space and time have no meaning in a universe where something can be in 2 places at once at the same time. Space and time are the fabric of the universe.
Is it possible that light is not the fastest thing in the universe? It seems like that would take a paradigm shift in our understanding. It may be possible to take a short cut through a worm hole at a place where the fabric of space-time folds back on itself. Perhaps in the process of building quantum computers we will learn things about quantum mechanics that enable us to eclipse Einstein's understanding of the universe, and find a basis for a truly unified field theory for atomic physics and quantum mechanics.
But throw this into the mix: The universe has been existing for billions of years without the knowledge or permission of human beings. The structure and function of the universe are constructs of human consciousness. Think of consciousness as a spectrum, like light. Do we only see part of the universe because our consciousness inhabits only part of the spectrum of consciousness?
"The great problem of any civilization is how to rejuvenate itself without rebarbarization." - Will Durant "We've kept more promises than we've even made" - Donald Trump "Of what meaning is the world without mind? The question cannot exist." - Edwin Land
MeDotOrg wrote:The universe has been existing for billions of years without the knowledge or permission of human beings. The structure and function of the universe are constructs of human consciousness. Think of consciousness as a spectrum, like light. Do we only see part of the universe because our consciousness inhabits only part of the spectrum of consciousness?
As Wittgenstein wrote:
"Whereof one cannot speak, thereof one must be silent."
There is probably no non-nonsensical way of attempting to articulate the nature and limits of the boundaries of our ability to conceive of things that are, for us, inconceivable.
Zadok: I did not have a faith crisis. I discovered that the Church was having a truth crisis. Maksutov: That's the problem with this supernatural stuff, it doesn't really solve anything. It's a placeholder for ignorance.