Discussion in 'General Science & Technology' started by paddoboy, Dec 31, 2015.
You'll be saying it a lot around here. Thanks for saying it. Maybe it will eventually sink in?
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You've done a yowmans job at researching the Internet for the links you've provided. Thanks.
No probs bruce: As I am so often saying, the variety cranks that infest this forum do so for many reasons:
 The crank weirdo that posts purposely anti science crap just to get a raise out of people.
The religious cranks that are concerned science has pushed back their need for any deity into near oblivion.
Those with delusions of grandeur that believe they are a reincarnation of Einstein.
The occasional Maverick physicist that are pushing an alternative model and agenda.
And we just happen to be the only outlet most of this brigade has to preach their nonsensical rants to.
If any of them had anything of a concrete nature, or with any substance at all, they would not be posting here, but would be seeking proper peer review and recognition.
You don't have to be rich to be a physicist. Most those dudes and dudetts are trying to get tenure for a little financial security. Go to school. Those tools you speak of will be made available to every student. Think about it. The logic path you described for becoming a physicist is nonsense.
Yet champions of science (I include myself in those ranks) continue to believe that scientific inquiry is a source of knowledge about the universe around us. 'Knowledge' has traditionally been defined as 'justified true belief'. If our scientific endeavor isn't even interested in whether what it says is true, then it's hard to imagine how its results could still be called knowledge.
I'll say that generally speaking, I'm a scientific realist. I persist in thinking that most of the central terms of our scientific theories possess reference to the real world, or at least are intended to refer. In your own chemistry, I think that most chemists believe that atoms and molecules really do literally exist, and aren't just conceptual conveniences whose role in chemical theories allows chemists to better predict outcomes when they mix liquids in glass bottles together or create stinks with their Bunsen burners.
Even the author of the OP seems to have reverted to the realist mode of thinking that he was otherwise dismissing when he wrote about caloric, "We now know there is no "heat fluid" known as caloric", suggesting that while caloric theory still works as a predictive instrument for observations as well as it ever did, science can't help thinking about what does and doesn't exist and caloric theory has seemingly been shown to be wrong about that.
Right, we agree on that.
'Truth' needn't imply logical necessity. If a proposition isn't a tautology, it can still be true.
I'm very much a fallibilist regarding science and everything else humans say they know, in the sense that every statement that we intend as a statement of truth may in fact be mistaken. (I'd even extend that to mathematics and logic.) That doesn't imply that we can't sometimes be right. I'm confident that we often are and that we already know a great deal.
That brings up the problem of the so-called 'pessimistic induction', the observation that if all of our outmoded scientific beliefs now seem to be false, it's only reasonable to think that from the point of view of the future everything science currently believes will be recognized as being false too. So we don't really know anything. I think that's the problem that the author of the OP is addressing, if only implicitly.
I kind of follow Popper in thinking in terms of verisimilitude (truthlikeness). While outmoded theories aren't entirely true, if they work at all then they do succeed in capturing something about reality. And the author is probably right in thinking that one way to capture that idea of truthlikeness is in terms of empirical adaquacy. Geocentric cosmology was and still continues to be a very good engine for predicting the future positions of heavenly bodies in the sky. Similarly, Einstein's theories will continue still work as well as they work today, even after they are eventually superceded by other theories in the future. They will continue to retain whatever verisimilitude they already possess.
But... even though we can say that medieval geocentric cosmology will works today as a predictive engine for observations of the sky from the earth, it's harder to argue that it continues to be right about the sun orbiting the earth once a day. That just seems to be wrong.
Old and outmoded theories might continue to produce useful predictions of observables, but the way they go about doing it (whether by geocentric cosmology or imagining the existence of vital spirits, caloric or phlogiston) might turn out to bear little resemblance to what is actually happening in the physical world.
Scientific theories do not deal in proof: But if by any accident any scientific theory should actually describe reality as it really is, then all well and good. [Evolution fits that category]
Scientific theories such as Newtonian and GR are most certainly correct within their known domains of applicability: GR being a classical theory does not cover quantum/Planck level. But in what it does cover, [from Newtonian through to relativistic speeds and masses, it gives correct results.
Even any future QGT that extends obviously beyond GR, will not invalidate what GR is already telling us, but should encompass it, while the QGT in itself again will probably not be the be all and end all.
If obtaining that 100% accurate precision to the utmost detail and reality is ever really possible to obtain.
I kinda like the maverick scientists. I know one who tends towards brilliance. His main interest is solutions to the field equations but he doesn't bother with writing papers, at least not lately, he just puts it on you tube. His other great interest is modifying the Alcubbiere spacetime to determine if it would be possible to shutdown the warp from the ship inside the warp spacetime or more importantly reduce the negative energy to sustain the warp spacetime. Not the most popular subject in physics. At least not lately. Kinda like Schmelzer.
I actually find the interest in the Alcubbiere spacetime as quite fascinating and interesting. Afterall we know that spacetime can be curved, bent, twisted and warped: All we need to do, is find the method to manually do this.
Schmelzer certainly knows his stuff as a professional, that is obvious, but just as obvious is the rather "warped" view even a physicist may take on certain issues for whatever reasons, if he has an agenda: The great Fred Hoyle also had his cross to bear in that he could not accept the BB.
Me too. I've been meaning to ask if you get the American syfy channel and the great series called Expanse? Right up your alley with a story centered on mining the asteroid belt and the politics with earth and a established Mars coloney and a Outer Planets Alliance. A bit like Dune in our solar system. The rocketry is advanced solar system. It's fun to watch.
Just wait 'til the aliens appear.
So you've read the books? I used to be a complete science fiction freak then I found the real science. I'll be looking for the aliens.
I'm about 1/3 of the way through the fifth book now - I saw episode 1, got hold of the books and started reading...
Making me jealous. Looks like some smart scifi. Thanks. Five books after one episode? Wow!
I'm weak in English you know ! And I'm not perfect to the bullshit ring of Dantes inferno. Happy new year.
I don't see it that way. You certainly speak more languages than me. I got your point. It is the bullshit ring of Dantes inferno. lOL. Just in case that was a joke. The Dante's inferno comment.
Sadly bruce, no we don't get that at this time: Sounds right up my alley! Please Register or Log in to view the hidden image!
You have given me an idea though: My Son is an IT expert and I may see if he is able to download episodes onto our system.
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It's pretty good. Have a good one.
They do this is beyond you because I can walk on earth surface but not to the black hole. How can I able to do that (black hole) sir ?
General relativity is a local theory of gravity that describes the natural motion of matter. The natural motion is freefall. These freefall paths are called geodesic paths. Inertial freefall paths with no forces disturbing them. Like Newton's first law Light and all other bosons follow a null geodesic while matter with mass, such as us, can follow different geodesic. These geodesic paths are determined by the local spacetime curvature. Matter tells the local spacetime curvature how to curve while the local spacetime curvature determines the path of matter. So if you could get within falling distance of the black hole you can find a geodesic which would carry you to r=0. The center of the black hole. There's much theoretical research ongoing to figure out what r=0 actually means.
For general relativity and this discussion it means the place where all geodesic paths, crossing the event horizon, end. What would happen to you over this path is depressing but theoretically interesting. lOL. It gets more interesting when falling into a rotating black hole. Most of the common knowledge is associated with the Schwarzschild black holes. This spacetime is the easiest to work with because it's limited to spherically symmetric non rotating uncharged black holes. This spacetime is commonly used to model weak fields like the near earth spacetime since the earth is rotating at the snail pace and is nearly spherically symmetric. Hey don't jump in the hole until I get there. Have a good one.
That's the whole thing with scientific knowledge. It's ridiculous to suggest scientists are not interested in whether their ideas are "true", but what we mean in the context of science is not logical truth, i.e. as opposed to falsehood. We are interested in physical REALITY. I think any scientist must believe there is an objective reality that the models strive to represent. To the extent that they succeed they are in a sense "true" models, but it is not absolute truth, or logical truth, or certainty. It is partial truth, probability, likelihood, approximation.
We tend to content ourselves with saying that such and such is "consistent with experiment" (or observation), rather than making a claim to "truth" as such. That is just modesty and common sense, given how science evolves.
P.S. Re reality of molecules, I had a physics teacher at school who professed to be agnostic on the subject of molecules. Whether this was just a pose or not, I do not know. He was an excellent teacher in fact. But you pick the sort of example that non-scientists always pick. What about the theory of organic reaction mechanisms - what physical chemists dismissively refer to as "arrow-pushing"? Or the idea of "Lewis Acids"? Or oxidation numbers? These are useful concepts in chemistry that account for what is observed, but we chemists all know they are just models that serve a purpose in predicting and may not reflect anything very fundamental. Or, again, is Newtonian gravitation "real"? You tell me, because I can't answer that yes or no. As with all things, there are shades of grey. Molecules seem real enough to physical scientists, but a lot of other theories are far less clear-cut.
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