What different methodologies are used for Freshwater tanks?

[Anonymous]

And I see you are not equiped to correct that ignorance.

So I guess the readers can determine for themselves.

ever shine a flashlight on a wall, and move it slowly farther away ?

because the intensity at the source remains constant, but that amount of light is now SPREAD OVER A LARGER AREA, the intensity of the light per unit of said area HAS TO DIMINISH

now show me how your neat copy and paste of inverse square laws contradicts that, as you claim to be doing :idea: :lol:

 

[Anonymous]

And I see you are not equiped to correct that ignorance.

So I guess the readers can determine for themselves.

ever shine a flashlight on a wall, and move it slowly farther away ?

because the intensity at the source remains constant, but that amount of light is now SPREAD OVER A LARGER AREA, the intensity of the light per unit of said area HAS TO DIMINISH

now show me how your neat copy and paste of inverse square laws contradicts that, as you claim to be doing :idea: :lol:

From the post before:

7.1.3 Spherical Waves
The wavefront emerging from (or collapsing into) a point is spherical. The area the
wave must cross increases as x2 +y2 +z2 = r2 (area of sphere is 4πr2). Therefore the
energy density drops as r2

So with a point source radiating in all directionsyou get an inverse square relationship. Twice the distance 1/4 the energy. As Len said inverse square requires and assumes a point source. And that is true for anything. Light, gravity, sound, matter, anything. As long as you have a point source radiating, shooting, attracting, or whatever equally in all directions.

A line source propagates in a cylinder from the line. The surface of that cylinder has an inverse relationship with the area of that cylinder. Therefore, twice the distance it 1/2 the density. Just as the reference stated and Len also.

An area source propagates as a plane. Therefore there is a constant relationship between density and distance. Twice the distance you have the same density. Just as the link stated and Len hesitated on.

You flashlight is neither a point or plane source because mainly of the reflector. Therefore it follows neither the inverse square or constant principle. Twice the distance the brightness is somewhere between 1/4 and 1 times the brightness. If you could get a "perfect" reflector the beam would not spread out and maintain a constant brightness. Just as Dr Sanjay's test of various reflectors indicated that some reflectors at twice the distance still have 90% of the brightness. and in one case only 1.9%ppfd was lost on a 3"x3" area with twicetehdistance.

You don't take the inverse square law and apply it to anything other then the assumed point source that generated the law. You can apply it to various points in the source, add all those up to predict what you should observe.when you do that with line and plane sources then you find the inverse and constant predictions.

my .02

 

[Anonymous]

you're wrong whenever you say that an increase in either distance or area reached, without a corresponding increase in the strength of the light source to accomodate for that increase in distance or area, will result in the same amount or intensity of light hitting that increased distance or area


a 12 year old will be able to grasp that intuitively-why can't you ?

 

[Anonymous]

oh, and btw-spewing out and parroting text does not mean you have ANY practical understanding of what happens to the subject you're parroting the text on

keep proving this to us, please



do you know that just by increasing the amount of plants in a tank, it's also possible to create a need for a more intense light source, due to more of the actual light energy entering the tank being used, (photons also bounce around,get reflected, etc., you know) and also due to the corresponding increase in shading inside the tank?

why have you never addressed this in your so-called 'expert' kakamaika ramblings here ?


you understand nothing

 

[Anonymous]

May I suggest you take your flashlight and measure the diameter of both the center spot and outer spot as the flashlight is moved from the wall in a dark room. Measure at every inch for a couple of feet, then every foot or so until you run out wall for the spot or run into a wall and can not back up any further. then compute the areas of the spots.

and plot area vrs distance, 1/area squared vrs distance, 1/area vrs distance. If there was in inverse square relationship the plot of 1/area squared would be a straight line. For an inverse, then 1/area would plot as a straight line. With a flash light you probably will not get a straight line because it is neither.

You see we did the same thing in HS physics with a light bulb, line of flourescents, and a whole ceiling of flourescents back in '63. Which you obviously have not done.

my .02

 

[Anonymous]

how's about you just measure the intensity on the wall w/a lux meter, you nincompoop. :idea:

you're sooo wrong that you're making yourself look more and more foolish with each and every post you make on the subject-REGARDLESS of the light type used,incandescent, fluorescent, OR halide- the intensity WILL decrease as distance is increased

IT HAS TO !
8O

:lol:

 

[Anonymous]

how's about you just measure the intensity on the wall w/a lux meter, you nincompoop. :idea:

you're sooo wrong that you're making yourself look more and more foolish with each and every post you make on the subject-REGARDLESS of the light type used,incandescent, fluorescent, OR halide- the intensity WILL decrease as distance is increased

IT HAS TO !
8O

:lol:

Why because Vitz say so?

Yet you weigh the same on the second floor as you do on the first and in the basement. According to your logic you should weigh less the further you are from the ground.

So what is the function of the intensity vrs distance?

Both Len and the link I posted state that inverse square requires a point source. A line source is an inverse relationship. The link stated that a plane source is constant intensity.

Dr. Sanjay's article on reflectors measured how the reflectors approach a plane source.

And you weigh the same on any floor of a house even though on a plantary level gravity follows the inverse square function.


So instead of measureing the flashlight, reading the articles and studying the theory and situation, all you can provide is "it has too".

It's a shame you don't want to increase your understanding of these things.

 

[Anonymous]

If you could get a "perfect" reflector the beam would not spread out and maintain a constant brightness

There will always be all sorts of things in the air ( dust, pollen, other particulates, changes in density of the fluid itself, etc) that would prevent this Bob, even over a very short distance. This is even more true in water. The bottom line is that light intensity will always decrease with distance...regardless if you had this theoritical perfect reflector or sharks with laser beams on their heads. :wink:

[/quote]

 

[Anonymous]

If you could get a "perfect" reflector the beam would not spread out and maintain a constant brightness

There will always be all sorts of things in the air ( dust, pollen, other particulates, changes in density of the fluid itself, etc) that would prevent this Bob, even over a very short distance. This is even more true in water. The bottom line is that light intensity will always decrease with distance...regardless if you had this theoritical perfect reflector or sharks with laser beams on their heads. :wink:

Which can then be factored in to produce the actual intensity in a given environment at a given location with given measuring equipment.

So first you take the light dissapation in air, which Dr sanjay's article indicates that sometimes a constant relationship is best. Then factor in the resistance of the water to predict the intensity at various deapths.

You don't just start assuming an inverse square relationship.

 

[Anonymous]

you're wrong whenever you say that an increase in either distance or area reached, without a corresponding increase in the strength of the light source to accomodate for that increase in distance or area, will result in the same amount or intensity of light hitting that increased distance or area


a 12 year old will be able to grasp that intuitively-why can't you ?

Intensity can also increase with distance. Which is why a magnifying glass can set paper on fire.

.02

 

[Anonymous]

If you could get a "perfect" reflector the beam would not spread out and maintain a constant brightness

There will always be all sorts of things in the air ( dust, pollen, other particulates, changes in density of the fluid itself, etc) that would prevent this Bob, even over a very short distance. This is even more true in water. The bottom line is that light intensity will always decrease with distance...regardless if you had this theoritical perfect reflector or sharks with laser beams on their heads. :wink:

Which can then be factored in to produce the actual intensity in a given environment at a given location with given measuring equipment.

So first you take the light dissapation in air, which Dr sanjay's article indicates that sometimes a constant relationship is best. Then factor in the resistance of the water to predict the intensity at various deapths.

You don't just start assuming an inverse square relationship.

I never assumed otherwise.

 

[tazdevil]

Which is why a magnifying glass can set paper on fire.

No, a magnifying glass then produces a new point of light source. It concentrates the original source to a point source at a given distance from the magnifying glass. Move to close or far from the magnifying glass and the effect is reduced, to eventually negated.

 

[Anonymous]

Which is why a magnifying glass can set paper on fire.

No, a magnifying glass then produces a new point of light source. It concentrates the original source to a point source at a given distance from the magnifying glass. Move to close or far from the magnifying glass and the effect is reduced, to eventually negated.

Which is why you have to do more than just apply the inverse square law. Sometimes you can assume a plant source for the most accurate representation of real world effects. With the intensity not changing with distance.

 

[Anonymous]

And you weigh the same on any floor of a house even though on a plantary level gravity follows the inverse square function

it does that because it is assumed the the POINT SOURCE of the field it THE CENTER OF THE PLANET therefore the difference between your first floor and second floor rooms is negligable.

the earth is 6378km in radius, therefore you will need to be that distance from the surface to be 1/4 of your weight

 

[Anonymous]

And you weigh the same on any floor of a house even though on a plantary level gravity follows the inverse square function

it does that because it is assumed the the POINT SOURCE of the field it THE CENTER OF THE PLANET therefore the difference between your first floor and second floor rooms is negligable.

the earth is 6378km in radius, therefore you will need to be that distance from the surface to be 1/4 of your weight

Which gives the same exact answer as assuming it is an area source. You have just given a usless, unmeasureable explaination to why the area source works.

But at planetary distance then we observe inverse square.

But with low earth satellites we observe deviations from elipses caused by the fact the earth is not a perfect point source.

So the concept of a plane source is useful. And the concept of a point source is also. but you have to apply these assumptions with the full understanding of exactly what the assumptions are and where the are best applied.

It is possible to observe a plane source with constant mangetude.

And it is impossible to measure a perfect inverse square (or line source or plane source) relationship. Only those within the accuracy of our current equipment.

 

[Anonymous]

how's about you just measure the intensity on the wall w/a lux meter, you nincompoop. :idea:

you're sooo wrong that you're making yourself look more and more foolish with each and every post you make on the subject-REGARDLESS of the light type used,incandescent, fluorescent, OR halide- the intensity WILL decrease as distance is increased

IT HAS TO !
8O

:lol:

Why because Vitz say so?

Yet you weigh the same on the second floor as you do on the first and in the basement. According to your logic you should weigh less the further you are from the ground.

So what is the function of the intensity vrs distance?

Both Len and the link I posted state that inverse square requires a point source. A line source is an inverse relationship. The link stated that a plane source is constant intensity.

Dr. Sanjay's article on reflectors measured how the reflectors approach a plane source.

And you weigh the same on any floor of a house even though on a plantary level gravity follows the inverse square function.


So instead of measureing the flashlight, reading the articles and studying the theory and situation, all you can provide is "it has too".

It's a shame you don't want to increase your understanding of these things.

:lol: :lol: :lol: :lol:

you do not weigh the same-you just don't have the precise enough tools to measure the difference-anyone who understands the basic concepts of gravity and newtonian physics can tell you that-just as anyone who's ever measured an old fashioned mechanical winding watch with a coilspring can tell you that it's speed changes as the relative position of the moon to it changes-DUE TO GRAVITY

i'll bet you deny the existence of the tides as well :lol: (and i'll bet that your weight changes as the moon's pull on the earth changes due to it's changing relative position-when the moon is at your opposite point on the globe, with the center of the earth between you, how much would you want to bet that your weight increases ?-i'll wager a years salary that it does-YOU cannot comprehend either what can be measured, NOR the raw physics you're quoting in a feeble attempt to seem knowledgable about the garbage you spew here to nooobs incessantly on this bb

(but by all means, please keep doing so-the noobs will eventually learn what to NOT do by way of what you spew they should do)

you most certainly DO weigh less the further away from the ground you are-it's the same physical law(s) that make you weigh one sixth of your earth weight on the moon, stupid

do you really think that gravity behaves differently due to distance involved? it most certainly does not-the effect itself is what's smaller-but the effect happens just the same-you weigh less even when you rise by only a foot-you just can't measure it (well, some very pricey esoteric equipment might be able to) with the equipment you have at hand.YOur weight is caused by gravity-distance, NO MATTER HOW SMALL OF AN INCREASE, WILL DECREASE THE EFFECT OF THAT GRAVITATIONAL PULL BY A CORRESPONDING AMOUNT

do you think that just because you can't percieve an incredibly small object, it doesn't get smaller when you halve it? :lol:

dude-you're so out of your league in both the logic and the science department, its frightening, given the education you claim to have had.

once again- i call nincompoop!

please think hard before your next post-it's almost embarrasing ME to point these basic things out to you

 

[Anonymous]

And you weigh the same on any floor of a house even though on a plantary level gravity follows the inverse square function

it does that because it is assumed the the POINT SOURCE of the field it THE CENTER OF THE PLANET therefore the difference between your first floor and second floor rooms is negligable.

the earth is 6378km in radius, therefore you will need to be that distance from the surface to be 1/4 of your weight

Which gives the same exact answer as assuming it is an area source. You have just given a usless, unmeasureable explaination to why the area source works.

But at planetary distance then we observe inverse square.

But with low earth satellites we observe deviations from elipses caused by the fact the earth is not a perfect point source.

So the concept of a plane source is useful. And the concept of a point source is also. but you have to apply these assumptions with the full understanding of exactly what the assumptions are and where the are best applied.

It is possible to observe a plane source with constant mangetude.

And it is impossible to measure a perfect inverse square (or line source or plane source) relationship. Only those within the accuracy of our current equipment.

what i have given is scientific fact. there is nothing you can say which deny's it, unless you apply 'beaslbob's first law of absolute BS'

 

[tazdevil]

How did gravity and weight get into a light intensity discussion? That's the fundemental law of physics I'm wondering about!

 

[Anonymous]

How did gravity and weight get into a light intensity discussion? That's the fundemental law of physics I'm wondering about!

:lol: :lol:


And more so how all this applies to various FW tanks.

In that physics class the teacher used an example of a butter gun buttering toast just to get the point across it doesn't make any difference what is being spread. :lol:

 

[Anonymous]

Well Bob, over the months with regard to fishkeeping, you've sure been spreading something since you got here, and it's not butter.

You're a terribly nice guy, and I respect you. I wouldn't send anyone to you for advice on animal husbandry though.