Invisible Light and Unhearable Sound?

I don't know but I'd expect there to be intense heat and perhaps that could light a spark or two. Sound doesn't travel in vacuum.

I feel like I'm missing the point here.

Reply to Hachem It depends upon each individual's sensitivity to change. Everyone is different and evolving differently. So I don't know what's you mean by "we". There is no such thing when it comes to the sensitivity of each individual mind.

Reply to TheMadFool
The point is that two objects collide in space where there is no medium to propagate sound waves to our ears. Maybe your are right, and only heat and light would be produced in space. I was just wondering, since the last Nobel Prize was awarded to gravitational waves, whether that is all that is present in space.

A silent Big Bang? Maybe be. But there is also something like background radiation, or "noise", or whatsoever.

As I said, I have really no idea.

Quoting Hachem

Would we hear it, or at least feel it?

If they were close enough that parts of the disintegrating comets hit the earth yes, if not no.
By parts I guess you would include expanding gas and solid material that could collide with the earth's atmosphere.

Reply to Sir2u
but before that, nothing?

Quoting Hachem

but before that, nothing?

I suppose that sound could be transmitted through the gas cloud, but I have no idea if the density would be sufficient to do so.

Reply to Sir2u

I do not mean sound specifically. I assume that we would not hear anything.

But would something like the LIGO detector notice anything going on in space? Like the LIGO detector, I have no idea whether it would react or not.

Quoting Hachem

But would something like the LIGO detector notice anything going on in space? Like the LIGO detector, I have no idea whether it would react or not.

No idea at all either, try one of the many scientific forums maybe.

Reply to Sir2u

Of course, if it were merely a technical question. But then, how would scientists make the distinction between those "sound" waves and other kinds of phenomena? Like gravitational waves for instance.

The metaphysics of space is never very far away, and that is something that concerns philosophers also.

Quoting Hachem

Of course, if it were merely a technical question. But then, how would scientists make the distinction between those "sound" waves and other kinds of phenomena? Like gravitational waves for instance.

That would be a scientific question that would be made on measurements they make and evidence that the come up from observations.

Quoting Hachem

The metaphysics of space is never very far away, and that is something that concerns philosophers also.

I doubt that the philosophers would do more than muddy the waters arguing over the meanings of the words the scientist use.

Reply to Sir2u
Yes, that is certainly a real danger. The problem is that scientists are usually worse philosophers than philosophers are bad scientists.

That's what makes you believe in fairy tales like Relativity and Quantum Theories. :)

Quoting Hachem

That's what makes you believe in fairy tales like Relativity and Quantum Theories. :)

Not sure where the faeries are there but OK.

Reply to Sir2u
good answer. I don't feel like going into that snake pit either.

Unreadable thread.

Quoting Hachem

That's what makes you believe in fairy tales like Relativity and Quantum Theories. :)

For me the real proof of science is in the pudding, in the tech that works. Human vanity is massive and ubiquitous. How do I separate the charlatans from those with the real thing? I ask them to perform "miracles" for me. Let's say that GM and QM are "myths" or "fairy tales." Call them what you want. They get things done.

Earth viewed from space

What good is fundamental physics to the person on the street?

This is the perennial question posed to physicists by their non-science friends, by students in the humanities and social sciences, and by politicians looking to justify spending tax dollars on basic science. One of the problems is that it is hard to predict definitely what the payback of basic physics will be, though few dispute that physics is somehow "good."

Physicists have become adept at finding good examples of the long-term benefit of basic physics: the quantum theory of solids leading to semiconductors and computer chips, nuclear magnetic resonance leading to MRI imaging, particle accelerators leading to beams for cancer treatment. But what about Einstein's theories of special and general relativity? One could hardly imagine a branch of fundamental physics less likely to have practical consequences. But strangely enough, relativity plays a key role in a multi-billion dollar growth industry centered around the Global Positioning System (GPS).

When Einstein finalized his theory of gravity and curved spacetime in November 1915, ending a quest which he began with his 1905 special relativity, he had little concern for practical or observable consequences. He was unimpressed when measurements of the bending of starlight in 1919 confirmed his theory. Even today, general relativity plays its main role in the astronomical domain, with its black holes, gravity waves and cosmic big bangs, or in the domain of the ultra-small, where theorists look to unify general relativity with the other interactions, using exotic concepts such as strings and branes.

But GPS is an exception. Built at a cost of over $10 billion mainly for military navigation, GPS has rapidly transformed itself into a thriving commercial industry. The system is based on an array of 24 satellites orbiting the earth, each carrying a precise atomic clock. Using a hand-held GPS receiver which detects radio emissions from any of the satellites which happen to be overhead, users of even moderately priced devices can determine latitude, longitude and altitude to an accuracy which can currently reach 15 meters, and local time to 50 billionths of a second. Apart from the obvious military uses, GPS is finding applications in airplane navigation, oil exploration, wilderness recreation, bridge construction, sailing, and interstate trucking, to name just a few. Even Hollywood has met GPS, recently pitting James Bond in "Tomorrow Never Dies" against an evil genius who was inserting deliberate errors into the GPS system and sending British ships into harm's way.

But in a relativistic world, things are not simple. The satellite clocks are moving at 14,000 km/hr in orbits that circle the Earth twice per day, much faster than clocks on the surface of the Earth, and Einstein's theory of special relativity says that rapidly moving clocks tick more slowly, by about seven microseconds (millionths of a second) per day.

Also, the orbiting clocks are 20,000 km above the Earth, and experience gravity that is four times weaker than that on the ground. Einstein's general relativity theory says that gravity curves space and time, resulting in a tendency for the orbiting clocks to tick slightly faster, by about 45 microseconds per day. The net result is that time on a GPS satellite clock advances faster than a clock on the ground by about 38 microseconds per day.

To determine its location, the GPS receiver uses the time at which each signal from a satellite was emitted, as determined by the on-board atomic clock and encoded into the signal, together the with speed of light, to calculate the distance between itself and the satellites it communicated with. The orbit of each satellite is known accurately. Given enough satellites, it is a simple problem in Euclidean geometry to compute the receiver's precise location, both in space and time. To achieve a navigation accuracy of 15 meters, time throughout the GPS system must be known to an accuracy of 50 nanoseconds, which simply corresponds to the time required for light to travel 15 meters.

But at 38 microseconds per day, the relativistic offset in the rates of the satellite clocks is so large that, if left uncompensated, it would cause navigational errors that accumulate faster than 10 km per day! GPS accounts for relativity by electronically adjusting the rates of the satellite clocks, and by building mathematical corrections into the computer chips which solve for the user's location. Without the proper application of relativity, GPS would fail in its navigational functions within about 2 minutes.

To be sure, I haven't done the experiments myself. I don't have the equipment. But what's more likely? The most massive conspiracy in human history? Or individual crankery on the internet?

Do you have a degree in science? If not, why are you trustworthy? Can we reasonably expect a scientific revolution from someone lacking either the will or the ability to pass undergrad classes? If so, you would presumably be in grad school by now. You would be presenting your ideas to actual scientists. The medium is [often the essence of] the message. The fact that you present your ideas here speaks against those ideas themselves. As I understand it, a true man or woman of science would not be offended by this kind of skepticism. So I hope you are not.

http://physicscentral.com/explore/writers/will.cfm

The author of the quote above is:

"Clifford M. Will is James S. McDonnell Professor of Physics at Washington University in St. Louis, and is the author of Was Einstein Right? In 1986 he chaired a study for the Air Force to find out if they were handling relativity properly in GPS. They were."

Quoting t0m

As I understand it, a true man or woman of science would not be offended by this kind of skepticism. So I hope you are not.

I pulled the door ajar to this snake pit, so I should not be surprised if somebody pulled it all open.

Here is what I have to say in a nutshell.

1) I do not share the metaphysical premises of Relativity and Quantum Theory.
Call it metaphysical prejudice.

2) I believe many of the proofs are in fact circular: they assume that which they are supposed to prove.
I will not try to prove it nor do I expect you to take my word for it.
Call it logical prejudice.

3) I do not deny the progress made in Physics since the 19 century, and certainly do not deny the contributions of scientists like Einstein or Bohr.

This is not so much a defense of my position regarding Relativity and Quantum Theory, as a simple indication of where I stand, whether my positions are justified or not.

I would be thrilled if instead of constantly getting general objections in which I have to tackle all of Science, which is certainly not my intent (I believe in science I just do not take scientists at their word), people looked at my attempts to raise the discussion of the basis on which contemporary Physics rests, the theory of light, above the level of generalities.

I have attempted in my other threads to circumscribe the issues as clearly as possible, and presented empirical objections to central tenets of the dual theory of light.

I find it regrettable that none of the people who were so eager to defend this theory has ever indicated in which way my attempts were flawed.

And no, I do not feel offended. In fact, I hope you will turn out to be up to the task in exposing the fallacies in my threads by something more than proofs of blind loyalty to the phase physical science is now in.

Just remember, Ptolemy was one of the greatest astronomers of Antiquity, if not the greatest. In the end, all his complex models and computations turned out to be wrong. So please do not talk to me of the achievements of Quantum and Relativity as something that proves once and for all that these theories are correct, and not at least susceptible to amelioration, if not simply replacement by better theories.

Every generation of scientists, and certainly physicists, is convinced that the level they have attained is the maximum that can be reached.

Just imagine what scientists of the 30th century will think of "our" pretensions.

I apologize for bringing up Relativity and Quantum at all.

Quoting Hachem

And no, I do not feel offended. In fact, I hope you will turn out to be up to the task in exposing the fallacies in my threads by something more than proofs of blind loyalty to the phase physical science is now in.

Respectfully, I think you betray yourself here. Who said anything about physical science being at an end? I'm more or less an instrumentalist. I trust the tech, because I can directly experience its success. The theory is justified in practice or as practice. If science was only "explanation," it would be the same old magical thinking. As I see it and value it, science makes accurate predictions and makes better technology possible. "Knowledge is power" can be interpreted as a criterion for knowledge.

I gave you reasons for my skepticism which you did not address. Why are you either not in school or not taking your scientific breakthrough to scientists? If what you are really doing is philosophy, then that's great. Or maybe you are doing philosophy of science. There's not a lot of that here, but I'm always happy to talk about Popper. He's one of my favorite philosophers. I'll even read a 150 word summary of your views and see what I can make of them. I've studied physics formally, but I did not specialize in physics. There's a big difference between undergrad classes and graduate education, so I make no great claims about my physics knowledge. But I'll be less of a party pooper and try to meet you half way.

So, sincerely, please provide or link me to a summary. This will not only be for my benefit. I think it will all of us here (and even you perhaps) to see where you're coming from. I mention this because I saw a thread where you started with a question about comets. I don't think that's the way to go. It's too "cute."
As I see it, no one likes to waste their time. So open with a bang. (I know. I know. The worst vice is ad-vice.)

Reply to t0m
I see you fall back on the same general strategy I have been facing until now.

Let us say I am wrong about my views considering Relativity and Quantum.

Let us say I am wrong considering the theory of the dual nature of light.

I make, even less than you, claims about my physics knowledge.

When we have established that I have no credentials to speak, or at least to be taken seriously, I hope you will find time to answer the specific questions concerning interference, newton rings and double slit.

I would be very interested in your explanation of the pictures which you can of course take yourself with a digital camera to make sure they were not photoshopped.

In other words, let us leave the secure space of epistemology and tread into one that should be dear to you: empirical knowledge.

Reply to Hachem

This is the kind of "cutesy" game-playing that puts me off. If you have an idea to share, then share it.

My guess is that you're a poet or a metaphysician who happens to be attached to the word "science." You're constrained by an unconsidered "scientism." I could be wrong. That's just my guess. If I'm right: Be a poet. Be a metaphysician. Be a mystic even. Because that's what "invisible light" and "un-hearable sound" remind me of.

Reply to t0m Reply to t0m
Not interested in

double slit experiment?
Newton rings?
Interference?
Optics?
Other problems in Physics?

No problem. Just don't waste my time and I won't waste yours. If all you can do is name calling and appeal to authority, then I am not interested.

Reply to Hachem

Sorry if I offended you. I didn't mean to be rude, but I think I was, after all, an A-hole.

Quoting Hachem

...about the distinction of sound as a sensation, and as a pure physical (non-biological) phenomenon.

This is a good theme for discussion. It's not new, but it remains fascinating. We experience reality sensually and yet tend to model it physically in terms of concepts like waves, etc., that are experienced conceptually. So what is the true sound? Our model of its cause? Or the first-person experience of sound? Am I on the right track?

Quoting t0m

Am I on the right track?

Certainly. And I am curious about how you look at it.

Reply to Hachem
For me we have something like a total experience. In this total experience I can open up a physics book and understand the kitchen table that I am reading this book on as "mostly empty space." Is this the truth of the table? Is my experience of it as something-to-read-on an "illusion"? As I see it, no.

As I see it, there's no real point in calling one perspective an illusion. The physics book gives us a way of looking at the world which is useful for certain human purposes among others. When I want to eat lunch, I can't use this "mostly empty space." I use the table as as familiar object that holds my food up at a height that is convenient for me. Similarly, when I listen to music, I am not thinking of pressure waves. Music for me in this situation is an irreducible experience. Bach is not "just" or "really" pressure waves. Of course we can and do blend ways of talking. We can say that pressure waves "deliver" the "message" or "signal" of Bach.

In general we can talk of the "manifest image" and the "scientific image" (I get these terms from Sellars.) The scientific image is, however, born from and only functions within the manifest image. We have to have "common sense" and learn lots of pretheoretical skills before we can even learn or make sense of the scientific image. I have to know English and how to handle a calculator, for instance, if I'm to learn to think in terms of the scientific image. Science evolved within a prescientific culture historically, too.

But the scientific image has been so powerful that many are tempted to understand it metaphysically. This is the position that sound is "really" soundless and that light is "really" invisible. (If this is what you were getting at, then I am doubly sorry for being so rude.) You might say that everything hinges on overloading this word "really." What really freed my mind on these matters was perhaps pragmatism and ordinary language philosophy. "Really" doesn't have a fixed meaning. We use it in all sorts of ways. There's an assumption about language often in play that traps our thinking from the get-go. We imagine that we are doing math with words. But words are far more "organic" than numbers. The total unit of meaning is all of human experience. To rip out words from this total context is a necessary and useful but imperfect process. Applying this idea to an example, we can think of the futility of mind-matter debates. The terms "mind" and "matter" have no fixed meaning. In ordinary use they function quite well. They form a useful but imperfect or fuzzy distinction. The metaphysician ignores this fuzziness as something contrary to his purpose (a word-math science of the absolute).


[quote=wiki]
"Philosophy and the Scientific Image of Man"[edit]
In his "Philosophy and the Scientific Image of Man" (1962), Sellars distinguishes between the "manifest image" and the "scientific image" of the world.
The manifest image includes intentions, thoughts, and appearances. Sellars allows that the manifest image may be refined through 'correlational induction', but he rules out appeal to imperceptible entities.
The scientific image describes the world in terms of the theoretical physical sciences. It includes notions such as causality and theories about particles and forces.
The two images sometimes complement one another, and sometimes conflict. For example, the manifest image includes practical or moral claims, whereas the scientific image does not. There is conflict, e.g. where science tells us that apparently solid objects are mostly empty space. Sellars favours a synoptic vision, wherein the scientific image takes ultimate precedence in cases of conflict, at least with respect to empirical descriptions and explanations.[7]

Unhearable sound and gravitational waves

Quoting Hachem

Imagine two comets colliding with each other mid-space, not far from Earth. Would we hear it, or at least feel it?

No. We'd neither hear nor feel it. ...unless a piece of it came our way and entered our atmosphere.

Michael Ossipoff