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Sundog
2nd May 2003, 11:42 AM
.

scribble
2nd May 2003, 11:48 AM
Originally posted by Sundog
She said she thought that the idea of any constants at all was kind of spooky, ever since I explained Avogadro's number to them. [/B]

I've felt the same way, ever since I learned about e. Surprisingly, pi didn't get me that way.

Anyhow, most constants are just based on boiled-down equations that describe physics as we've observed it. Nothing magical or spooky about them, it's just the way the universe as we've seen it seems to work.

Pi makes a great example, because it's easy to show how it's derived from the ratio of a circle's radius to circumference.

I'll wait for a braniac to come along and explain things better -- I'm curious, too.

-Chris

Zombified
2nd May 2003, 12:14 PM
Some physical units are essentially a matter of units and scale - how you measure things. h has the value it does because we use macroscopic units to measure energy and time. Sometimes physicists adopt so-called "natural units", a system of units where h-bar (along with c) work out to 1, then you don't carry them around in the equations. Of course, you need to make sure you convert back to natural units correctly.

Also, what used to be a physical constant in the old days is now a matter of definition. Length or time aren't defined the same way today as in the 19th century, so instead of defining the meter and the second and the measuring the speed of light, the speed of light is defined to be a certain number, and then the second is defined be how far light can go a certain distance, given some definition of the meter.

It might sound a little backwards, but once you've proven a certain value is, in fact, constant, the definition works. These definitions are rather more precise and repeatable than the old definitions.

Martin
2nd May 2003, 12:35 PM
It's worth noting that not all advertised constants actually are. Hubble's constant, for instance, has an annoying habit of changing with time. Bad constant! Bad!

The coupling constant for the strong nuclear force is another - this one changes with distance, such that the strong force is weak enough at close range that standard perturbative approaches work just fine. They break down at longer ranges where the coupling constant gets irritatingly large. The coupling constant is known as a 'running' constant. This appears to mean something along the lines of 'oops, we were wrong'.

whitefork
2nd May 2003, 01:31 PM
Originally posted by Sundog
Even the "mystery" of the sequence of digits in pi becomes rather uninteresting when we realize that it's not a function of the number pi itself, but an artifact of our place value numbering system.

Math geniuses, am I correct in believing that only transalgebraic numbers cannot be thought of in this way? I'm no math genius, but pi is transcendental in any number base. The ratio of diameter to circumference can never be rational on a euclidean plane. (with curved space, you can make it work I imagine but then the curvature would be a transcendental number - not sure about that)

CurtC
2nd May 2003, 02:00 PM
I'm reading the book The Elegant Universe by Brian Greene. In it, he first goes over relativity and quantum mecanics, with the stated goal to bring the reader up to speed enough on those concepts to then get into the concepts of string theory. One of the things he points out from the QM section is how it's all based on something like 19 constants - the mass of the electron, the size of a unit charge, etc. The same thing bothered him too - where did these arbitrary numbers come from? He promised that string theory holds the potential to describe an elegant system where those "fundamental" constants of the QM world are derived from the features of the strings. I can't say exactly how yet, since I haven't reached that point of the book.

I must say that I would be very proud if my kids came up with the question. Especially since they're only 6 and 2 right now, but at any age. I look forward to having those kinds of conversations.

And the book The Elegant Universe is an excellent read (so far). I'd highly recommend it.

jj
2nd May 2003, 04:30 PM
Originally posted by Sherlock Holmes
Dear all,

Technically speaking, physical constants don't exist, and they certainly aren't physical.

Sincerely,

S. Holmes

Do tell. Do you think that there is a specific, quantized charge on each electron, or not? (note, I mean the "mean" or "expected" charge, of course)

Now, no waffling about units, can I simply count this in terms of "electron charges"?

Yes or no?

PygmyPlaidGiraffe
2nd May 2003, 05:04 PM
Originally posted by Sundog
OK all you braniacs,

The other night I was discussing Planck's constant with my kids. They understood the basic idea of quantifying energy, but then my daughter asked me something I didn't have a good answer for - why are there physical constants at all? Any of them? She said she thought that the idea of any constants at all was kind of spooky, ever since I explained Avogadro's number to them.

Wow, ask the hard questions why don't you?

Kids have the propensity to stump adults don't they:D

gn:

I learned the

standard acceleration of gravity

in high school.

I could not tell anyone though why there are constants. I have accepted gn because I participated in experiments that demonstrated gn.

The constants are helpful because they can help make predictions and determine outcomes but I can offer no new insight into this perplexing query.

Crossbow
2nd May 2003, 06:31 PM
The values of Physical Constants are determined in order to actually determine the data in question.

For example if one wants to know the area of circle that has a radius of 5 meters, then the actual area is:

25*pi*m^2

While that answer may be accurate, it is not terribly useful, so a better answer would be:

78.54 m^2

Now then, if you are asking why is it that these constants have the value that they do, then I expect that relates to some of the basic physical questions of the universe such as: Why is the charge on the electron set at the value it has? Why is not greater, or lesser? And so on.

I expect that those types of answers are found within the Grand Unified Theroy (which does not exist yet).

I hope this helps!

rwguinn
2nd May 2003, 09:13 PM
Originally posted by Sundog
OK all you braniacs,

The other night I was discussing Planck's constant with my kids. They understood the basic idea of quantifying energy, but then my daughter asked me something I didn't have a good answer for - why are there physical constants at all? Any of them? She said she thought that the idea of any constants at all was kind of spooky, ever since I explained Avogadro's number to them.
They are all based on convention.
A second is our basic unit of time. A meter is defined as so many wavelengths of a specific frequency of light (back to time again). Mass is defined based on the local units of (m/sec^2). Avagadro's number is the number of molecules in a mole (mass based on atomic weight), etc, etc. They are what we always called "the Hurley heat Factor", which is what you add to make things come out right after you multiply through by 0.00
Only the units change- the values, once converted to our units don't...
unless they do.
I'm so confused!! I think I've read too much of the Hechee sagas....

Roger

Walter Wayne
2nd May 2003, 09:26 PM
Well, I think a physical constant basically describes a relationship between various phenomenon. Hmmm. thats no really a good description. Ignore the first sentence.

[pedantic mode]Would it note be more accurate to call pi a mathmatical constant. Pi is the ratio of the circumfrance of a to its radius in a euclidean plane. It only has relevance to reality to the degree a euclidean plane represents reality.[/pedant mode]

Walt

jj
2nd May 2003, 11:07 PM
Originally posted by Sherlock Holmes

Dear jj,

I don't know, but I will investigate it.

Sincerely,

S. Holmes

The answer is "yes". It's been a constant so far.

scribble
2nd May 2003, 11:54 PM
Originally posted by Walter Wayne
Well, I think a physical constant basically describes a relationship between various phenomenon. Hmmm. thats no really a good description. Ignore the first sentence.

Nahh, that's great.

[pedantic mode]Would it note be more accurate to call pi a mathmatical constant. Pi is the ratio of the circumfrance of a to its radius in a euclidean plane. It only has relevance to reality to the degree a euclidean plane represents reality.[/pedant mode]

Walt

Uh... all constants only have limited application.

Do you dismiss C because it is only the speed of light in a vacuum? No. It's still a good constant.

Tesserat
3rd May 2003, 12:30 AM
posted by crossbow
For example if one wants to know the area of circle that has a radius of 5 meters, then the actual area is:

25*pi*m^2

While that answer may be accurate, it is not terribly useful, so a better answer would be:

78.54 m^2

Speaking of constants, the area of any circle is a constant, zero.

by definition:
A circle is the locus of all
points equidistant from a central point

the circle itself has no area. The two dimensional space bounded by the circle (or the smaller of the two spaces bounded by the circle), has an area that can be calculated by pi * radius^2

I've won a few beers with that one.

Soapy Sam
3rd May 2003, 02:34 AM
"All numerical values are constants, until they change; at which point they become different numerical values."

The above statement, so far as I can see, is both true and tautological. It's because I think exclusively verbally that I kept coming up with things like this in high school mathematics and physics classes, whereupon frustrated teachers would throw blackboard dusters at me.

I wish I could think mathematically, or visually. Maybe Sundog's daughter could log on here someday and explain mathematics to me. It has to be done simply. Despite several strong recommendations of Brian Greene's book, I'm afraid I gave up about chapter five. Too, too turgid.

I think the most amazing thing about Pi is its ubiquity. That the ratio of a circle's diameter and circumference is constant seems trivial; that actuarial death rate statistics and other esoteric phenomena often feature Pi in their formulae beggars belief.
This IS spooky.

BillyJoe
3rd May 2003, 05:32 AM
Originally posted by rwguinn
A meter is defined as so many wavelengths of a specific frequency of light. Not quite......

The meter is the length of the path travelled by light in vacuum during a time interval of 1/299 792 458 of a second. Incidentally, this definition fixes the speed of light in a vacuum at exactly 299,792,458 mps
You may have been confused with the definition of the second....
The second is the duration of 9 192 631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom.
International System of Units (http://physics.nist.gov/cuu/Units/current.html)

rwguinn
3rd May 2003, 08:11 AM
Originally posted by BillyJoe
Not quite......

Incidentally, this definition fixes the speed of light in a vacuum at exactly 299,792,458 mps
You may have been confused with the definition of the second....

International System of Units (http://physics.nist.gov/cuu/Units/current.html)
Actually, you kinda made my point-because of who/what/where we are, we use one measure to define the other---sorta like defining "fast=not slow" and "slow=not fast":)
Roger

BillyJoe
3rd May 2003, 08:32 AM
yeah but.....it all hinges on the constancy of the speed of light in a vacuum.

rwguinn
3rd May 2003, 08:39 AM
Originally posted by BillyJoe
yeah but.....it all hinges on the constancy of the speed of light in a vacuum.
Yepper-which makes them constants everywhere we know of, which gets us right back to the "spooky" statement...

Walter Wayne
3rd May 2003, 11:01 AM
Originally posted by scribble
Do you dismiss C because it is only the speed of light in a vacuum? No. It's still a good constant. I wasn't dismissing pi by any means. Just the anal retentive part of me likes to seperate "mathmatical" and "physical" constants.

A mathmatical contstant can be know precisely, and can be found with no knowledge of the physical universe (pi and e come to mind)

Physical constants must be measured physically (k, c and G).

Didn't mean to start a debate about the topic.

Walt

Paul C. Anagnostopoulos
3rd May 2003, 12:22 PM
Keep in mind that a constant has a unit, while a number does not. Pi is a number; Avogadro's constant is a constant.

So in the case of pi and e, the question becomes "Why are there numbers?"

I love pedantics [sic].

~~ Paul

Walter Wayne
3rd May 2003, 12:40 PM
Originally posted by Paul C. Anagnostopoulos
Keep in mind that a constant has a unit, while a number does not. Pi is a number; Avogadro's constant is a constant.

So in the case of pi and e, the question becomes "Why are there numbers?"

I love pedantics [sic].

~~ Paul
Which means if a choose my system of units properly. I can make those constants into numbers :)

Naturalized units are so fun.

rwguinn
3rd May 2003, 04:06 PM
Originally posted by Sherlock Holmes

Dear jj,

Is it truly a constant? Perhaps the value has changed over time or is changing slowly over time. Is the charge right now the same value as it was at a Big Bang?

Perhaps we simply cannot measure it accurately either.

Sincerely,

S. Holmes

all physical constants change with time-as we get better and better at measuring them, for starters. the speed of light has been refined numerous times to the point where we now define it. The actual value didn't change-just our capability of measuring it. The same can be said for numerous other values.
As far as whether they have changed since the "big Bang", who can possibly know with certainty.
Leaving no stone unturned in the search for answers is one thing. Upending mouse turds is an entirely different thing. If the electron charge is changing, we can't measure the rate of change. Skepticism CAN be carried too far.

Roger

BillyJoe
3rd May 2003, 05:48 PM
Originally posted by rwguinn
.....all physical constants change with time-as we get better and better at measuring them, for starters. Not true.....

Originally posted by rwguinn
.....the speed of light has been refined numerous times to the point where we now define it. The actual value didn't change-just our capability of measuring it. ....the speed of light in a vacuum, for example has its final value of 299,792,458 mps.

Zombified
3rd May 2003, 06:15 PM
The speed of light has that value by definition. This definition was adopted in 1983 when the meter was defined as the distance light goes in a certain interval of time. The second was defined in 1967 to be a certain number of cycles of a given atomic emission.

The experimental statement "the speed of light is constant" was based on previous experiments when the second and meter had different, independant definitions. Those experiments and theory that goes with them justifies the new definition.

jj
3rd May 2003, 06:53 PM
Originally posted by Sherlock Holmes

Dear jj,

Is it truly a constant? Perhaps the value has changed over time or is changing slowly over time. Is the charge right now the same value as it was at a Big Bang?

Perhaps we simply cannot measure it accurately either.

Sincerely,

S. Holmes

Dear Sherlock,

Please go study something in a physics or chemestry book. Even a very VERY small change would have changed the entire evolution of the universe, would have created massive changes in chemestry, etc, etc.

In other words, there is a massive pile of evidence against any change to speak of, other than purely tautological change (i.e. a change in the "basis vectors" themselves).

Before you continue asking your pseudo-skeptical questions, there is some obligation on your part to actually study the fields that you are questioning.

You remind me of people in the audio field who question issues like the need for double-blind tests, the Shannon-Nyquist theorem, the Shannon Capacity Theorem, and the like. You like to ask trivial, annoying questions that seem profound to you.

Well, now the ball is in your court. If you're going to be a critic, LEARN YOUR SUBJECT FIRST!

jj
3rd May 2003, 06:54 PM
Originally posted by Sherlock Holmes

Dear BillyJoe,

Could you prove that?

Sincerely,

S. Holmes

Once again, your glib nihilism is exposed. I suggest that you read back a few articles and find the answer to your own question, which was in fact given.

Furthermore, if you're asking something you didn't ask, "is the speed of light changing", GO STUDY SOME COSMOLOGY AND LEARN WHAT THE IMPLICATIONS OF THAT WOULD BE.

Thank you for being trying,

JJ

BillyJoe
3rd May 2003, 08:06 PM
Originally posted by Sherlock Holmes
Dear BillyJoe,

Could you prove that [the speed of light in a vacuum.....has its final value of 299,792,458 mps]?
See Zombified last post and my fourth last post.

BillyJoe
3rd May 2003, 08:38 PM
Originally posted by Sherlock Holmes
Billyjoe posted that "the speed of light in a vacuum, for example has its final value of 299,792,458 mps". It seemed reasonable to ask how he ascertained that it has a final value.I was replying to rwguinn who said..........all physical constants change with time-as we get better and better at measuring them.....In other words I was responding to the measuring problem not whether the constants have changed over time.

Zombified
3rd May 2003, 09:27 PM
Originally posted by Sherlock Holmes
Billyjoe posted that "the speed of light in a vacuum, for example has its final value of 299,792,458 mps". It seemed reasonable to ask how he ascertained that it has a final value.Do you now understand the answer?
Anyway, I believe it is possible that something could be changing very slowly without us being able to know at the present moment.Given that the current definition of units is based on a constant c, what you are asserting is that the fine structure constant is changing. FYI. Because the fine structure constant appears in equations governing the emission of microwaves and other EM energy from atoms in, say, very distant objects, there is strong astrophysical evidence that the change in the fine structure constant since very early in the universe (10% of its current age or less) is rather less 1 part in ten thousand, and in all but one study statistically consistent with zero.

rwguinn
3rd May 2003, 09:38 PM
Originally posted by BillyJoe
Not true.....

....the speed of light in a vacuum, for example has its final value of 299,792,458 mps.
I think that was my point? up untill 1983, the capability of measuring the speed of light in a vacuum didn't enable us to settle on a particular value. At that point, the units of measurement were resolved to give it a value.
Measuring your car's speed with 1%accuracy gives a 1mph error at 100mph. 1%accuracy measuring "c" is 2,997,924.58 meters/sec-, .1% is 299,792.458 m/sec, both of which are a fairly large problem....
notice that the actual speed is not in question, nor does it change-just the units defining it.

jj
3rd May 2003, 11:32 PM
Originally posted by Sherlock Holmes

Dear jj,

With all respect, everyone is ignorant on if a small change would have changed the evolution of the universe or not. If you know for sure jj, then you'd be able to tell us what would happen if it was 10^-20 smaller than what it is now.[/B]

You're asserting it's undetectable?

Prove it. Please specifically address the effects it would have on chemical binding.

jj
3rd May 2003, 11:35 PM
Originally posted by Zombified
Do you now understand the answer?
Given that the current definition of units is based on a constant c, what you are asserting is that the fine structure constant is changing. FYI. Because the fine structure constant appears in equations governing the emission of microwaves and other EM energy from atoms in, say, very distant objects, there is strong astrophysical evidence that the change in the fine structure constant since very early in the universe (10% of its current age or less) is rather less 1 part in ten thousand, and in all but one study statistically consistent with zero.

I'm heading out on a business trip. Can you explain to him the effects on specrtra and chemical bonding if the charge on the electron changes?

He cited 1 part in 10^20, and claimed that it was impossible for anyone, ever, any time, to know if it had changed by that much.

BobM
4th May 2003, 10:39 AM
Speed of Light has changed, claims so-and-so (http://aca.mq.edu.au/lightspeed.html)

Zombified
4th May 2003, 11:29 AM
Originally posted by BobM
Speed of Light has changed, claims so-and-so (http://aca.mq.edu.au/lightspeed.html) This was discussed previously on another thread. To summarize, there is one study which suggests that the fine structure constant may have changed by a minute amount. It is not a well established result yet. Prof. Davies has produced an outline of an argument based on general relativity which suggests that if the fine structure constant changed in the direction the study predicts, it would be more consistent with thermodynamics to interpret the change in the fine structure constant as a variation in c rather than in the charge of the electron.

The purpose of the letter, however, was not to argue that the fine structure constant has actually changed, or that c has changed, it was to introduce the notion of using black hole thermodynamics to analyze issues of cosmological significance and make choices between alternate interpretations of data. A useful idea, but one which is not yet highly developed.

But of course that doesn't make for such a great headline.

To be clear, scientists do not dogmatically insist that c cannot or has not changed, in fact, there are any number of studies looking for such an effect. It's quite common for scientists to look for violations of well-accepted rules. Papers and theses are published all the time which report negative results that set upper bounds on how much certain quantities can vary. So far, there isn't much compelling evidence that c has ever changed.

jj
6th May 2003, 08:26 AM
Originally posted by Sherlock Holmes

Dear jj,

I never mentioned I could prove it, nor did I mention anything about 'chemical binding'.

Sincerely,

S. Holmes

You asserted that a particular sensitivity was indetectable. I suggested some considerations that you mustmake

You refuse to do your homework.

You are, therefore, dismissed on the basis that you can not provide even words, let alone evidence, for your assertion.

jj
6th May 2003, 10:23 AM
Originally posted by Sherlock Holmes

I proposed that the speed of light might be changing in such small amounts that we aren't able (at this time anyway) to detect it.

You proposed that the charge on an electron may have changed relative to all other physical constants.

You asserted that a change of 1 part in 10^20 would be forever undetectable.

Please show your evidence. In doing so, address whatever effects this charge change would have on line spectra, chemical reactions, and how they both would relate to the charge on a proton.

Until you can deal with the actual assertions you make, instead of the ones you wish to retract to, you are again dismissed. You are unwilling and unable to do your homework, and your blatant avoidance of your own proposals speaks very strongly to your ability to discuss the subjects you raise.

Again, provide evidence, any evidence FOR the claim that the charge on the electron may have changed.

Stand and deliver.

jj
6th May 2003, 10:41 AM
Originally posted by Sundog
Or not. :D :p

Err, ok, ok, ok...

He's started to "change" what he demands as his understanding evolves from complete ignorance to partial ignorance. So there might be hope, but I'll ignore him from now on if you insist, since he is most obviously a troll.

Dancing David
6th May 2003, 12:13 PM
Please do not insist on posting in those ridiculous large fonts! It makes you look like a total weenie with no self control.

Sherlock makes a very good point, the speed of light is not constant wether you like it or not jj, and there is no proof that it hasn't changed over time, small changes in the speed of light would not cause the universe to colapse. I am not an idiot either and I do read a lot on cosmology before you go off the deep end.

The speed of light is an average over time and distance, there was research into this in Italy about three years ago where they were researching the fact that some photons arrive at different times even though thier original propagation was simultaneous. It has something to do with concepts involving Feynmna sum of histories, the average of the speed of light is a constant, the speed varies on the level of an individual photon for very small time periods. I don't know if the experiments were replicated.

I would like to know where you get your info jj, why does the speed of light have to be constant over time? If lambda exists and the acceleration rate of the universe is increasing, why would we assume that photons at 1 sec. after the big bang propagate at the same speed they do now?

Even relativity does not require that the speed of light be constant over epochs of time, it mainly talks about the fact that most field effect propagate at the speed of light.

I find the notion of the constants to be a very interesting one. Why do the Plank numbers exist? I like to think myself that there are three field in the Universe and that they all expand, some particles are collapsed relative to these fields and it is the difference between the rates of expansion between the three fields that produce the constants that we see in experiments.

Peace
dancing David

Dancing David
6th May 2003, 12:14 PM
Or what Sundog, will you call him a fa*got!

Peace
dancing David

Zombified
6th May 2003, 12:57 PM
Originally posted by Dancing David
Sherlock makes a very good point, the speed of light is not constant wether you like it or not jj, and there is no proof that it hasn't changed over time, small changes in the speed of light would not cause the universe to colapse. I am not an idiot either and I do read a lot on cosmology before you go off the deep end.Does this mean you are familiar with the cosmological evidence, based on fine structure spectra of distant objects, that the speed of light has not changed?
The speed of light is an average over time and distance, there was research into this in Italy about three years ago where they were researching the fact that some photons arrive at different times even though thier original propagation was simultaneous. It has something to do with concepts involving Feynmna sum of histories, the average of the speed of light is a constant, the speed varies on the level of an individual photon for very small time periods. I don't know if the experiments were replicated.
You've misinterpreted the experiment. This has to do with the uncertainty principle, and has nothing whatsoever to do with variations in the speed of light.
I find the notion of the constants to be a very interesting one. Why do the Plank numbers exist? I like to think myself that there are three field in the Universe and that they all expand, some particles are collapsed relative to these fields and it is the difference between the rates of expansion between the three fields that produce the constants that we see in experiments.
Cool. Perhaps you'd like to expand on this point by providing us with the Langrangians for the interactions of these fields.

Dancing David
6th May 2003, 01:33 PM
Okay so the spectra remain contant for distant objects, except for the red shift right? And that means that the speed is constant because otherwise the frequency would shift more than the red shift.(I know there is a distance that it constant between spectral lines) Makes sense to me, maybe not to Sherlock, sorry I started reading the thread at the large font.

I thought that because the indeterminancy principle applied to the actual arrival of the photons that it also meant that sometimes they travelled at a speed that was not constant, obviously you know more about this than me. So is the speed not really subject to indeterminancy? I understand that it just may be an artifact of the measurement, and that the photons may not be varying in speed, there just may be variation in the measurement of the arrival, right?

All I said was that I had a notion, sorry, I don't have the math to express it, I barely have enough math to pretend to understsand the equations in the books.

I just have always had a hard time conceptualizing gravity as an attractive force mediated by the exchange of gravitons.(I said that I am not an idiot, I know I am not a genius) And for me it is easier to imagine that we live in the area of these expanding fields(undefined just imagined by me), and so why does an object fall? Because each object that has mass is collapsed relative to this expanding field, therefore objects fall because the space beween them expands past them and they don't move along with the expanding space. ( I said it was a notion, I didn't say that it made sense or that I could justify it, it just makes better sense to my head). In the same sense electrons do repel each other because they are both on the expanding field, while opposite charges attract because they are collapsed with respect to each other. I have no justification for these notions they just make sense to me. I know that electrons probably repel because they can't occupy the same space.

So I stuck my foot into it, Sherlock is very annoying at times, but he is free to say what he wants.

Peace
dancing David

Martin
6th May 2003, 02:44 PM
Originally posted by Sherlock Holmes
The definition of things are based on the most accurate measurements at the time. We don't have any evidence to say that they are truly constantYou contradict yourself. Could it be that you are confusing evidence with absolute proof?

Martin
6th May 2003, 02:46 PM
Originally posted by Sundog
I give up. I'm through trying to create interesting, meaningful threads here. It's hopeless; the woo-woos take over every single timeDon't give up, just stick him on ignore. Problem solved.

Zombified
6th May 2003, 02:46 PM
Originally posted by Dancing David
Okay so the spectra remain contant for distant objects, except for the red shift right? And that means that the speed is constant because otherwise the frequency would shift more than the red shift.(I know there is a distance that it constant between spectral lines) Makes sense to me, maybe not to Sherlock, sorry I started reading the thread at the large font.The evidence is based on comparing the spacing of various spectral lines. The idea is to compare things in such a way that red shift cancels entirely and the comparison won't be biased by red shift. Red shift affects all frequencies equally.
I thought that because the indeterminancy principle applied to the actual arrival of the photons that it also meant that sometimes they travelled at a speed that was not constant, obviously you know more about this than me. So is the speed not really subject to indeterminancy? I understand that it just may be an artifact of the measurement, and that the photons may not be varying in speed, there just may be variation in the measurement of the arrival, right?Momentum is indeterminant (if you are measuring position as well), but speed is only part of the momentum.

A way to look at this is energy-time uncertainty. Just like position-momentum uncertainty, if you know precisely the energy of a particle, you won't know exactly when it interacts with something, or vice versa. There's an uncertainty limit on exactly when a photon goes past a certain point, based on how well you know its energy.

All I said was that I had a notion, sorry, I don't have the math to express it, I barely have enough math to pretend to understsand the equations in the books.Fair enough. Sorry if I sounded overly confrontational. My point is physicists don't just make this stuff up, there's precise reasoning behind it.
I just have always had a hard time conceptualizing gravity as an attractive force mediated by the exchange of gravitons.(I said that I am not an idiot, I know I am not a genius) And for me it is easier to imagine that we live in the area of these expanding fields(undefined just imagined by me), and so why does an object fall? Because each object that has mass is collapsed relative to this expanding field, therefore objects fall because the space beween them expands past them and they don't move along with the expanding space. ( I said it was a notion, I didn't say that it made sense or that I could justify it, it just makes better sense to my head). In the same sense electrons do repel each other because they are both on the expanding field, while opposite charges attract because they are collapsed with respect to each other. I have no justification for these notions they just make sense to me. I know that electrons probably repel because they can't occupy the same space.
There is a repulsive effect between electrons because of their inability to be in the same state, but that is seperate from and on top of the electrostatic repulsion, which is much stronger.

Unfortunately, physics is not always intuitive. It can't be helped. Just as we are no longer at the center of the solar system, or the special creation of a God that prefers us over all other creatures, we also have to come to terms with the fact that the physical world was not designed to be easily understood (or rather, we are not designed to understand things not at our scale). Just because a physical theory is difficult to visualize does not make it wrong.

Zombified
6th May 2003, 02:48 PM
Originally posted by Sundog
I give up. I'm through trying to create interesting, meaningful threads here. It's hopeless; the woo-woos take over every single time.

Thanks anyway, those of you who had such interesting things to say before it turned into an idiot-fest.
This forum seems to be rather less so than R&P. It would be unfortunate if it never got any traffic.

Dancing David
6th May 2003, 02:56 PM
Sundog:
Just ignore SH and be glad he isn't followed by an Ignorant Troll.

Peace
dancing david

Zombified
6th May 2003, 02:59 PM
Originally posted by Dancing David
Are you referring to Planck's constant (h and/or h-bar)?

6th May 2003, 03:00 PM
Dear Sundog,

Here is your post you posted a moment ago and then deleted

Sundog
Critical Thinker
Registered: Apr 2003
Location: Posts: 366
I give up. I'm through trying to create interesting, meaningful threads here. It's hopeless; the woo-woos take over every single time.Thanks anyway, those of you who had such interesting things to say before it turned into an idiot-fest
Last edited by Sundog on 05-06-2003 at 10:35 PM

My response is that you might be frustrated with my level of science, but that is no good reason to lose your temper.

Remember that people asked me questions, and I was responding to them in addition to posting comments directly relating to my thoughts on if constants are actually constants.

In a Science forum, I have every right to chime in as anyone else. That is a large part of what makes science science; you have to pay attention to everyone's ideas, even though you might not like them at all.

Very sincerely yours,

S. Holmes

Dancing David
6th May 2003, 03:47 PM
As I recall Plank's h-bar is the more inertesting of the two, I will have to read some at home.

Does Heiesenberg's indeterminanacy count as a constant?

Peace
dancing David

Dancing David
6th May 2003, 03:55 PM
Sherlock, enough already! Say something meaningful or you will be the first person I set to ignore.
You ignore what they say to you, have you tried to understand it?
This is the science forum, acting like Socrates is not going to win you points. If you have point to make then make it already. If this was the philosophy forum it okay to just spout off, here you need to follow the method and put up or shut up. I defended you and you still act like a program randomly generating phrases.

In the Philosphy forum it is okay to make genral statement about how nothing is provable, this is the Science forum. Why do they have to spell out for you how the speed of light is determined, any decent search engine will show you where to go.

Peace
dancing david

Martin
6th May 2003, 04:01 PM
Originally posted by Dancing David
acting like Socrates is not going to win you pointsQuaffing some hemlock might :D

Sundog
6th May 2003, 04:03 PM
Originally posted by Dancing David
Sundog:
Just ignore SH and be glad he isn't followed by an Ignorant Troll.

Peace
dancing david

I'm not going anywhere.

I'm just shutting up.

Zombified
6th May 2003, 05:53 PM
Originally posted by Dancing David
As I recall Plank's h-bar is the more inertesting of the two, I will have to read some at home.

Does Heiesenberg's indeterminanacy count as a constant?I wouldn't say either is more interesting; they differ by only a factor of 2pi. h-bar usually simplifies the algebra when dealing with angular velocities or frequencies, that's it.

Heisenberg's uncertainty principle is not a constant, it is a mathematical statement about relationships between measurements of some variables. The minimum uncertainty is generally some number times Planck's constant, but that is a matter of units. (In some sense, Planck's constant establishes the scale of our conventional units.)

Sherlock: I have that copy of Nature, though I'm not sure which critically-stable stack of papers its under. Look for the previous thread on this subject, I gave a summary of Davies' letter.

Dancing David
7th May 2003, 07:36 AM
Zombie:

I realize that HIP is a scaling thing, I just suggested it might be like a constant.

So does HIP apply to the speed of light? I thought thats what the Italian researchers were claiming. Or was it an artifact of the measurement.(Thats what I understood HIP to be, an artifact of trying to get wavicles to act like particles.)

Pardon my ignorance.

Peace
dancing David

Zombified
7th May 2003, 10:39 AM
Originally posted by Dancing David
I realize that HIP is a scaling thing, I just suggested it might be like a constant.I don't understand what you mean by this. I'm not sure how an equation can be like a constant.

So does HIP apply to the speed of light? I thought thats what the Italian researchers were claiming. Or was it an artifact of the measurement.(Thats what I understood HIP to be, an artifact of trying to get wavicles to act like particles.)The speed of light is fixed. It is the distance travelled and the travel time that is somewhat uncertain. The average value should work out to the right number, but if you don't properly account for all the particles you may misinterpret the situation.

Dancing David
7th May 2003, 01:23 PM
Sorry I think I was fuddled and meant constant as in always there.

Now I am real confused about the HIP and the speed of light, it is our measurement that is subject to the HIP and that intorduces the illusion that the c-limit was violated? I thought that they presented the original findings as something that did violate the c-limit for short period of time/distance, guess that they were just too thrilled to trash einstien.

Peace
dancing David

Zombified
7th May 2003, 02:18 PM
Originally posted by Dancing David
Now I am real confused about the HIP and the speed of light, it is our measurement that is subject to the HIP and that intorduces the illusion that the c-limit was violated? I thought that they presented the original findings as something that did violate the c-limit for short period of time/distance, guess that they were just too thrilled to trash einstien.That the experiment showed speed greater than C is considered to have been a misinterpretation that's been cleared up. Nobody's perfect.

But there's an important point here: scientists DON'T take these rules for granted, they go looking for violations. Sometimes experiments are ambiguous, hard to correctly interpret, or show statistical fluctuations. These problems are usually cleared up. Sometimes something new is discovered.

jj
7th May 2003, 06:30 PM
Originally posted by Sherlock Holmes

Dear Mr. jj,

I am free to propose anything I want. That doesn't mean that I claim that I can prove any of it. Also, I'm not dogmatically saying that the change has occured or that we won't ever be able to detect one if it had (etc.).

Sincerely,

S. Holmes

If that's the case, why do you even ask. Now, asking questions is not bad, but asking rhetorical questions that you have no idea of the answer to or utility of, is a rhetorical game, plain and simple, one intended to show uncertainty and a lack of understanding on the part of the person you're challenging.

So, if you admit you have no idea, I guess your rhetoric is completely indicted.

jj
7th May 2003, 06:32 PM
Originally posted by Sherlock Holmes

Dear Mr. jj,

I will take up your advice and study cosmology, physics, chemistry, mathematics, and logic like you have. :rolleyes:

Now you're making claim. Exactly what and how much have I studied cosmology, physics, chemistry, mathematics and logic?

You had better be prepared to spend some time, too.

I don't claim expertise in all the subjects, but I dare say I manage to be fairly well informed and have at least most of the basics in hand.

If you did the same thing, you'd understand the fundamental silliness of some of your questions.

jj
7th May 2003, 06:35 PM
Originally posted by Dancing David
I would like to know where you get your info jj, why does the speed of light have to be constant over time? If lambda exists and the acceleration rate of the universe is increasing, why would we assume that photons at 1 sec. after the big bang propagate at the same speed they do now?

Perhaps you should, now, check how the units and 'C' are defined.

Perhaps you fail to understand the implicit properties of how the measurement is made?

The actual, raw speed (meaning what in reletivistic terms is somewhat interesting, yes) may change, but in the current measurement system, the number given will not, rather other basic units will change accordingly.

It's that simple, really. If you did the work before you opened your mouth and prated at folks, you'd have known. I'm not the first person to have explained this in this thread.

I hope you feel some satisfaction in piling on.

jj
7th May 2003, 06:37 PM
Originally posted by Sherlock Holmes
No, before you are jj ask for my mathematical derivation which you wouldn't even read, I don't have any proof, nor did I claim to.

In this case, you're right. A "mathematical proof" would mean exactly NOTHING.

Science uses empirical testing, remember? Whatever would a "mathematical deriviation" show in the pure abstract, here, without supporting fact, measurement, and evidence?

jj
7th May 2003, 06:40 PM
Originally posted by Zombified
But there's an important point here: scientists DON'T take these rules for granted, they go looking for violations. Sometimes experiments are ambiguous, hard to

And, those new, surprising violations are a very important place where new findings come from.

7th May 2003, 09:19 PM
Originally posted by jj

I don't claim expertise in all the subjects, but I dare say I manage to be fairly well informed and have at least most of the basics in hand.

Dear jj,

I too am 'fairly informed' and have a basic understanding of the topics.

Sincerely,

S. H.

Dancing David
8th May 2003, 12:03 PM
Originally posted by jj

Perhaps you should, now, check how the units and 'C' are defined.

Perhaps you fail to understand the implicit properties of how the measurement is made?

The actual, raw speed (meaning what in reletivistic terms is somewhat interesting, yes) may change, but in the current measurement system, the number given will not, rather other basic units will change accordingly.

It's that simple, really. If you did the work before you opened your mouth and prated at folks, you'd have known. I'm not the first person to have explained this in this thread.

I hope you feel some satisfaction in piling on.

Excuse me JJ I do understand the proof about the electrons, where did you prove that the spped of light is constant over different epochs, I will reread the thread and see if I can find it.

You say I prate I say you are smarmy, feel better ? You still look like a fool for using the large fonts and maybe SH is just laughing at you.

Peace

Dancing David
8th May 2003, 12:06 PM
In fact you just stated that the raw speed may change, sheesh are you trying to contradict yourself? Of course relativity doesn't care if the speed is the same or not, assuming that gravitation propagates at the speed of light. I was talking about the raw speed.

Peace

Dancing David
8th May 2003, 12:11 PM
Sherlock I thought that you had something to add but I just voted you off my island! You are an ignorant troll with an overinflated ego. Nyah Nyah Nyah, I shun you!

Peace
to you and yours.

Dancing David
8th May 2003, 12:26 PM
Originally posted by Zombified
Do you now understand the answer?
Given that the current definition of units is based on a constant c, what you are asserting is that the fine structure constant is changing. FYI. Because the fine structure constant appears in equations governing the emission of microwaves and other EM energy from atoms in, say, very distant objects, there is strong astrophysical evidence that the change in the fine structure constant since very early in the universe (10% of its current age or less) is rather less 1 part in ten thousand, and in all but one study statistically consistent with zero.

Hey I found it and I stand corrected, I will now do a search on fine structure. This is alot easier to read without SH's posts.

Imagine me banging my head whist seated in zarei.

JJ if you are ever in central Illinois I will buy you the beverage of choice.

Later dude
peace

8th May 2003, 01:50 PM
Originally posted by Dancing David
Sherlock I thought that you had something to add but I just voted you off my island! You are an ignorant troll with an overinflated ego. Nyah Nyah Nyah, I shun you!

Peace
to you and yours.

Dear Mr. Dancing David,

Your post, on the other hand, adds a lot to the discussion. Apparently your ego is super-tiny, yet you point out that others are ignorant and have large egos. :rolleyes:

I have found some interesting websites regarding this topic that I have been reading. There is a good mix of sites that actually offer opposing views.

Sincerely,

S. H.

DrMatt
8th May 2003, 01:57 PM
I've seen several experiments designed to measure the speed of light in a vacuum and try to detect even tiny purturbances in it. Most of them work like this:

[list=1]
Get a really long tube in which to run your light. If necessary, bend it around corners with mirrors.
Put additional mirrors on the ends of the tube to make the path of light even longer.
Make sure most of the tube is black matte material so any stray light will be absorbed.
At the mouth of your now-effectively-very-long optical echo chamber, put a device which uses tiny pulses of electricity to generate sparks in the vacuum. Also put in a light sensor which detects the sparks.
Wire the light sensor to an oscilliscope, and tune the spark generator so the detected flash appears as a pulse on the oscilliscope.
The light returning from the long path and hitting the light-sensor makes a second pulse on the oscilliscope. The effective length of the tube coupled with the time delay observed by the oscilliscope provide data to measure the speed of light.
Make sure that suddenly halving the path of the light actually halves the time delay, so you know that the timelapse you're seeing actually is due to the length of the reflector tube.
[/list=1]

People have been trying to observe variations in the vaccuum speed of light by methods like this one for about 98 years now.

Dancing David
8th May 2003, 02:27 PM
The papers about the reseach by Moffat and Rueglio seem to be speculative and cosmological in nature about the variable speed of light, I didn't see testable hypothesis in thier conclusions.

The fine structure papers seem to point to the one in ten thousand shift, which they felt was significant at the time in 2001, I didn't see any recent reference to replecation of the work, although it does make an interesting read, as do the general papers on fine structure. The authors of the studies seemed to feel that the 1-10,000 was signifiicant. And I do understand that the fine structure research is dependant on the frequency of light/speed of light.

What I found interesting is that the shift was variable for different spectral lines and that magnesium was used as an anchor. I would assume this is due to QM and the different frequency response being limited to certain conditions, in certain shells.

But the 2001 papers point to alpha being different back in time, was thier further research which hasn't been published on the web?

Peace