In the context of this discussion, there was no point in telling us that your definition was the only definition. We were talking about sunlight, which includes infrared light.
And no, reading that articles proves exactly what i've been saying, that the word has multiple definitions.
By your definition, gamma rays are also light. The sun produces a spectrum that is vastly larger than the one we call light. Just because it produces it, and we use the term sunlight doesn't mean that it's all considered to be light. People were using the term sunlight thousands of year before infrared and ultraviolet were even suspected.
Link to the total definition of those, or quote the entire one, as I did. Your selective quoting is misleading.
Are you serious? Are you seriously claiming that i'm a lying?
Those are exact, copy and pasted definitions from those dictionaries. They're not out of context. They are copy and pasted, including the entire text from the bullet point. Sure, there are other definitions listed. But that's been my point the entire time. That your definition isn't the only one. There are multiple definitions for "light", some of which include non-visible parts of the spectrum.
Melgross, you should be ashamed of this behavior. You're so afraid of appearing to be wrong, that you've basically called a (hopefully) respected member a liar.
If I posted links to those definitions, would you admit that light has more than one definition? That it can refer to non-visible parts of the spectrum?
Are you serious? Are you seriously claiming that i'm a lying?
Those are exact, copy and pasted definitions from those dictionaries. They're not out of context. They are copy and pasted, including the entire text from the bullet point. Sure, there are other definitions listed. But that's been my point the entire time. That your definition isn't the only one. There are multiple definitions for "light", some of which include non-visible parts of the spectrum.
Melgross, you should be ashamed of this behavior. You're so afraid of appearing to be wrong, that you've basically called a (hopefully) respected member a liar.
If I posted links to those definitions, would you admit that light has more than one definition? That it can refer to non-visible parts of the spectrum?
I'm saying that those snippets are not enough. please don't try to turn this into something it's not. If I gave those short definitions, you would have said the same. You've already accused me of several things in this conversation, and this one is VERY annoying.
If you're not happy, then I suggest you take it up with an admin, and have him look at all the posts between us.
Those aren't snippets. Those are exact and entire definitions copy and pasted without any modification at all. What you're failing to grasp is that words have multiple definitions.
It is interesting to note that you aren't willing to say "if you post links I'll admit to those definitions".
How many links to definitions will it take?
If those links are posted will you admit to being wrong? Or will you just claim that those dictionaries are wrong too?
I would like to apologize for contributing to derailing this thread!
But hopefully everyone else has been as entertained by this study in psychology as I have been. Really, the various definitions of "light" aren't that fascinating. What has interested me though is the culture of this board and how engaged some people are with not being wrong, myself included.
With that said, I'll bow out of sticking up for one of the above poster's valid use of the word light. I'll let Melgross have the last word in proclaiming the only definition of "light".
(Well, unless melgross walks into the trap of being willing to admit wrong when links are posted to dictionaries which have more than one definition of the word light. In which case, i'll return and post some links. Enjoy! )
Those aren't snippets. Those are exact and entire definitions copy and pasted without any modification at all. What you're failing to grasp is that words have multiple definitions.
It is interesting to note that you aren't willing to say "if you post links I'll admit to those definitions".
How many links to definitions will it take?
If those links are posted will you admit to being wrong? Or will you just claim that those dictionaries are wrong too?
So, instead of arguing this, why then don't you post the links. Quite frankly, these don't look like entire definitions.
Quote:
Dictionary.com: "a similar form of radiant energy that does not affect the retina, as ultraviolet or infrared rays."
American heritage: "Electromagnetic radiation of any wavelength."
Webster: "a form of radiant energy similar to this, but not acting on the normal retina, as ultraviolet and infrared radiation"
Those are full definitions? The first and last don't even look like complete sentences, or definitions. The middle one is clearly not complete, as no one would ever define light as "electromagnetic radiation of any wavelength.".
I'll quote the definition further down which says Physics:
Quote:
a. Electromagnetic radiation that has a wavelength in the range from about 4,000 (violet) to about 7,700 (red) angstroms and may be perceived by the normal unaided human eye.
b. Which you quoted, is derived from a. It doesn't include gamma rays. It doesn't include the radio spectrum. It doesn't include microwaves, and it doesn't include infrared or ultraviolet. It includes the visible spectrum from 400 to 700 nm, as I stated way back in the beginning.
So, no, what you quoted was NOT the full definition.
Now, should I look up the other ones as well?
Just to end this, if you really want me to, I'll grant you near infrared and near ultraviolet. Under certain limited circumstances, it MAY be considered to be light in some definitions. But not infrared and ultraviolet in their totality, as not even insects can see that far out.
So you're flat out calling me a liar. It's tough, but i'll refrain from rebutting.
If i post the links, will you admit to being wrong?
I'm not calling you anything. I simply posted the ENTIRE definition that Dictionary.com has for light, which is far longer than that one sentence you posted. I then showed where that sentence came from and what it means. Did you read that?
If you want to say that I CALLED you a liar, that's your concern.
I'd be delighted if you did post the other links, as you think you should. Just let's make sure it's understood how scientific definitions work. The definition of greatest meaning is written first, and the others are derived from increasingly smaller subgroups. They never contradict the previous definition. So if the first one says any number between 2 and 8, and the second said any number, it's understood to mean any particular number between 2 and 8.
In other words, "b" can never broaden the definition already set by "a".
If you want to argue that, then don't bother. This isn't a literary discussion
So, instead of arguing this, why then don't you post the links. Quite frankly, these don't look like entire definitions.
Those are full definitions? The first and last don't even look like complete sentences, or definitions. The middle one is clearly not complete, as no one would ever define light as "electromagnetic radiation of any wavelength.".
It's also on the wikipedia page on light:
"Light is electromagnetic radiation, particularly radiation of a wavelength that is visible to the human eye (about 400–700 nm, or perhaps 380–750 nm[1]). In physics, the term light sometimes refers to electromagnetic radiation of any wavelength, whether visible or not.[2][3]"
The phenomenon of emission of electrons from a metallic surface when illuminated by "light of appropriate wavelength or frequency is known as photoelectric effect.
Different substances emit photoelectrons when subjected to different radiations. For instance, X-rays incident on heavy metals eject electrons from K, L shells. Certain semi-conductors like transistors respond to infrared radiations. The alkali metals respond very well to visible and ultraviolet radiations."
But hey...what does the author of Comprehensive Physics know about light?
I'll quote the definition further down which says Physics:
b. Which you quoted, is derived from a. It doesn't include gamma rays. It doesn't include the radio spectrum. It doesn't include microwaves, and it doesn't include infrared or ultraviolet. It includes the visible spectrum from 400 to 700 nm, as I stated way back in the beginning.
So, no, what you quoted was NOT the full definition.
No...b is not derived from a. It means that light also refers to radiant energy such as ultraviolet or infrared. In fact definition a) ALSO clearly indicates that light is "Also called luminous energy, radiant energy." and the definition of radiant energy is:
"radiant energy
–noun Physics.
1.\tenergy transmitted in wave motion, esp. electromagnetic wave motion.
2.\t light 1 (def. 2a)."
Quote:
Now, should I look up the other ones as well?
Just to end this, if you really want me to, I'll grant you near infrared and near ultraviolet. Under certain limited circumstances, it MAY be considered to be light in some definitions. But not infrared and ultraviolet in their totality, as not even insects can see that far out.
Please. If the physicists refer to X-Ray light then full range of UV and IR counts.
"Swift-detected GRB080307 showed an unusual smooth rise in its X-ray light curve around 100s after the burst, at the start of which the emission briefly softened."
"The Advanced Light Source (ALS), a division of Berkeley Lab, is a national user facility that generates intense light for scientific and technological research. As one of the world's brightest sources of ultraviolet and soft x-ray beams--and the world's first third-generation synchrotron light source in its energy range--the ALS makes previously impossible studies possible."
"The Linac Coherent Light Source (LCLS) produces ultrafast pulses of X-rays millions of times brighter than even the most powerful synchrotron sources — pulses powerful enough to make images of single molecules."
Gee...them physicists sure are dumb to call a linear accelerator a light source. They called them x-rays light where any damn fool knows if you can't see it, you can't call it light.
Another example where gracefully admitting you were wrong would have resulted in less embarrassment. 30 seconds of googling X-Ray and Light resulting in scads of hits from national laboratories calling their big assed accelerators and synchrotrons LIGHT SOURCES.
But obviously you have a better understanding of the word "light" than physicists.
Back to e-ink. It appears to be a common problem for some e-ink panels. Common enough to get a blog post on kindleworld:
"At the same time, customers in forums have helped one another by asking those with problems to take their Kindles into direct sunlight and hold it there for a minute or so, and to try a page turn with it while doing so. As with the Kindle 1, some units don't do well in direct sunlight, showing fading of fonts. Any such unit would be a defective one, which Amazon customer reps now recognize, and they will replace such units honoring the basic warranty with a 1-day shipment of another boxed Kindle 2. This has made a difference for those whose problems had more to do with something in the circuitry of some units."
"The official word from amazon cs was that faulty e-ink receptors in some of the first batch of kindle 2's were the source of the problem. It is a defect and the k2 is not supposed to do this so for those of you who haven't tested your device in sunlight you might want to look into it.'
Personally, I don't read a lot in direct sunlight except at the beach. I'd rather take a paperback there than risk an expensive ebook. So for me LCD works better.
"Light is electromagnetic radiation, particularly radiation of a wavelength that is visible to the human eye (about 400?700 nm, or perhaps 380?750 nm[1]). In physics, the term light sometimes refers to electromagnetic radiation of any wavelength, whether visible or not.[2][3]"
The phenomenon of emission of electrons from a metallic surface when illuminated by "light of appropriate wavelength or frequency is known as photoelectric effect.
Different substances emit photoelectrons when subjected to different radiations. For instance, X-rays incident on heavy metals eject electrons from K, L shells. Certain semi-conductors like transistors respond to infrared radiations. The alkali metals respond very well to visible and ultraviolet radiations."
But hey...what does the author of Comprehensive Physics know about light?
No...b is not derived from a. It means that light also refers to radiant energy such as ultraviolet or infrared. In fact definition a) ALSO clearly indicates that light is "Also called luminous energy, radiant energy." and the definition of radiant energy is:
"radiant energy
?noun Physics.
1.\tenergy transmitted in wave motion, esp. electromagnetic wave motion.
2.\t light 1 (def. 2a)."
Please. If the physicists refer to X-Ray light then full range of UV and IR counts.
"Swift-detected GRB080307 showed an unusual smooth rise in its X-ray light curve around 100s after the burst, at the start of which the emission briefly softened."
"The Advanced Light Source (ALS), a division of Berkeley Lab, is a national user facility that generates intense light for scientific and technological research. As one of the world's brightest sources of ultraviolet and soft x-ray beams--and the world's first third-generation synchrotron light source in its energy range--the ALS makes previously impossible studies possible."
"The Linac Coherent Light Source (LCLS) produces ultrafast pulses of X-rays millions of times brighter than even the most powerful synchrotron sources ? pulses powerful enough to make images of single molecules."
Gee...them physicists sure are dumb to call a linear accelerator a light source. They called them x-rays light where any damn fool knows if you can't see it, you can't call it light.
Another example where gracefully admitting you were wrong would have resulted in less embarrassment. 30 seconds of googling X-Ray and Light resulting in scads of hits from national laboratories calling their big assed accelerators and synchrotrons LIGHT SOURCES.
But obviously you have a better understanding of the word "light" than physicists.
I've had enough physics to know what physicists mean by the word "light". Yes, even in textbooks there are errors. Unfortunately, sometimes we use terms that we don't mean the way we say them. I've used the term infrared light too, even though I know it's incorrect, simply because it's heard so often it isn't thought about. The first reference, using the proper definition is still the correct one. The term "light year" for example is used to mean the distance ANY electromagnetic wave travels in a year, just because all of then travel at the speed of "light". It doesn't mean that physicists think that all of the spectrum is "light". And, so, yes, words seep into texts that don't belong there. We've all had texts where that has happened. It doesn't change things.
Don't be funny. LED is a categorical definition of a process defined device. If you don't know that then don't bother. The LED was invented a long time ago, well before the infrared version came on the scene. You might as well use the heat lamp, which produces mostly infra red, as a light to read by, with its leakage of some visible spectrum and call it a reading light.
There's not much more point to this.
Geez...wrong again.
"In 1961, experimenters Robert Biard and Gary Pittman working at Texas Instruments,[11] found that GaAs emitted infrared radiation when electric current was applied and received the patent for the infrared LED.
The first practical visible-spectrum (red) LED was developed in 1962 by Nick Holonyak Jr., while working at General Electric Company.[2] "
The IR LED preceded the visible light LED.
From the Wikipedia LED entry. The original source is this:
"In 1961, experimenters Robert Biard and Gary Pittman working at Texas Instruments,[11] found that GaAs emitted infrared radiation when electric current was applied and received the patent for the infrared LED.
The first practical visible-spectrum (red) LED was developed in 1962 by Nick Holonyak Jr., while working at General Electric Company.[2] "
The IR LED preceded the visible light LED.
From the Wikipedia LED entry. The original source is this:
Yes, the physical effect was noted long before someone actually invented usable LEDs.
However, the IR LED patent preceded visible light LED patent by a year. Therefore the IR LED invention preceded the invention of visible light LEDs. Both are LIGHT emitting diodes by the way.
Or were you being imprecise and using the term "invented" vs "discovered"? Or more likely just wrong again?
I've had enough physics to know what physicists mean by the word "light". Yes, even in textbooks there are errors. Unfortunately, sometimes we use terms that we don't mean the way we say them. I've used the term infrared light too, even though I know it's incorrect, simply because it's heard so often it isn't thought about. The first reference, using the proper definition is still the correct one. The term "light year" for example is used to mean the distance ANY electromagnetic wave travels in a year, just because all of then travel at the speed of "light". It doesn't mean that physicists think that all of the spectrum is "light". And, so, yes, words seep into texts that don't belong there. We've all had texts where that has happened. It doesn't change things.
So you're saying that when they named the Advanced Light Source and LCLS these physicists were dumber than you and didn't know the meaning of the word light? Because you took a physics class?
Whatever. Getting you to admit you're wrong about anything is like tilting at windmills. Not even the full quotes you demanded changes anything. Instead all of those people are incorrect in their usage of the term light because you say so.
Has it ever occurred to you that the term "visible light" itself is an indicator that there is "non-visible light" and is not a tautology? If the term light ONLY ever referred to the EM spectrum that can be seen by the human eye the "visible" adjective need never be applied? And certainly not so widely applied?
That when top physicists refer to IR light or UV light that they aren't being imprecise? But maybe applying a different adjective to describe a specific form of "light" and that the term light can be applied for the entire EM spectrum because hey...they're all just photons with different energy levels?
Nah...that could NEVER be.
Oh...and learn to use the dictionary. Your Merriam Webster definition supports dfiler and not you.
"c: electromagnetic radiation of any wavelength that travels in a vacuum with a speed of about 186,281 miles (300,000 kilometers) per second; specifically : such radiation that is visible to the human eye"
Meaning that the Pope is a COMMON meaning of pontiff (because he's the bishop of Rome) but not the ONLY meaning and there is a more GENERAL definition that PRECEDES it (bishops in general are pontiffs).
So one GENERAL definition of light is electromagnetic radiation of any wavelength.
Further the "c" indicates a SUBSENSE, and is not predicated on the previous SUBSENSES. They are separate but related meanings of the term.
"The system of separating the various senses of a word by numerals and letters is a lexical convenience. It reflects something of their semantic relationship, but it does not evaluate senses or set up a hierarchy of importance among them."
Senses and subsenses are semantically related...not semantically dependent. The "job" example in that same area shows this.
"At job the date indicates that the earliest unit of meaning, sense 1a, was born in the seventeenth century, and it is readily apparent how the following subsenses are linked to it and to each other by the idea of work. Even subsense 1d is so linked, because while it does not apply exclusively to manufactured items, it often does so, as the illustrative quotation suggests."
1d is not ALWAYS linked to previous related historical meanings of the word (1a - 1c). it is grouped because it is OFTEN related.
Yes, the physical effect was noted long before someone actually invented usable LEDs.
However, the IR LED patent preceded visible light LED patent by a year. Therefore the IR LED invention preceded the invention of visible light LEDs. Both are LIGHT emitting diodes by the way.
Or were you being imprecise and using the term "invented" vs "discovered"? Or more likely just wrong again?
I'm not wrong either time. What I should have said was that it was known first. The term invented becomes sticky when something is known a long time before.
So you're saying that when they named the Advanced Light Source and LCLS these physicists were dumber than you and didn't know the meaning of the word light? Because you took a physics class?
Whatever. Getting you to admit you're wrong about anything is like tilting at windmills. Not even the full quotes you demanded changes anything. Instead all of those people are incorrect in their usage of the term light because you say so.
Has it ever occurred to your that the term "visible light" itself is an indicator that there is "non-visible light" and is not a tautology? If the term light ONLY ever referred to the EM spectrum that can be seen by the human eye the "visible" adjective need never be applied? And certainly not so widely applied?
That when top physicists refer to IR light or UV light that they aren't being imprecise? But maybe applying a different adjective to describe a specific form of "light" and that the term light can be applied for the entire EM spectrum because hey...they're all just photons with different energy levels?
Nah...that could NEVER be.
Oh...and learn to use the dictionary. Your Merriam Webster definition supports dfiler and not you.
"c: electromagnetic radiation of any wavelength that travels in a vacuum with a speed of about 186,281 miles (300,000 kilometers) per second; specifically : such radiation that is visible to the human eye"
Meaning that the Pope IS a pontiff, and a COMMON meaning of pontiff but not the ONLY meaning and there is a more GENERAL definition that PRECEDES it.
So the GENERAL definition of light is electromagnetic radiation of any wavelength.
Further the "c" indicates a SUBSENSE, and not predicated on the previous SUBSENSES. They are separate but related meanings of the term.
"The system of separating the various senses of a word by numerals and letters is a lexical convenience. It reflects something of their semantic relationship, but it does not evaluate senses or set up a hierarchy of importance among them."
Senses and subsenses are semantically related...not semantically dependent. The "job" example in that same area shows this.
I give up. As you know, My physics background is much more than " a physics class". But you have none.
In the case mentioned, by the way, "specifically" means accurately. That's also from Mirriam-Webster.
Oh, forget it.
Jeez, you wont even accept what the dictionary says what it means when it uses a term? Those aren't random definitions of the word but the INSTRUCTIONS ON HOW TO USE THE DICTIONARY FROM THE DICTIONARY ITSELF.
You want to forget it because you're completely wrong and simply refuse to admit it. Again.
Jeez, you wont even accept what the dictionary says what it means when it uses a term? Those aren't random definitions of the word but the INSTRUCTIONS ON HOW TO USE THE DICTIONARY FROM THE DICTIONARY ITSELF.
You want to forget it because you're completely wrong and simply refuse to admit it. Again.
I'm going to let you feel good, and stop posting on this. but if you don't I will delete them
Comments
In the context of this discussion, there was no point in telling us that your definition was the only definition. We were talking about sunlight, which includes infrared light.
And no, reading that articles proves exactly what i've been saying, that the word has multiple definitions.
By your definition, gamma rays are also light. The sun produces a spectrum that is vastly larger than the one we call light. Just because it produces it, and we use the term sunlight doesn't mean that it's all considered to be light. People were using the term sunlight thousands of year before infrared and ultraviolet were even suspected.
Then you'd better read it again.
Link to the total definition of those, or quote the entire one, as I did. Your selective quoting is misleading.
Are you serious? Are you seriously claiming that i'm a lying?
Those are exact, copy and pasted definitions from those dictionaries. They're not out of context. They are copy and pasted, including the entire text from the bullet point. Sure, there are other definitions listed. But that's been my point the entire time. That your definition isn't the only one. There are multiple definitions for "light", some of which include non-visible parts of the spectrum.
Melgross, you should be ashamed of this behavior. You're so afraid of appearing to be wrong, that you've basically called a (hopefully) respected member a liar.
If I posted links to those definitions, would you admit that light has more than one definition? That it can refer to non-visible parts of the spectrum?
Are you serious? Are you seriously claiming that i'm a lying?
Those are exact, copy and pasted definitions from those dictionaries. They're not out of context. They are copy and pasted, including the entire text from the bullet point. Sure, there are other definitions listed. But that's been my point the entire time. That your definition isn't the only one. There are multiple definitions for "light", some of which include non-visible parts of the spectrum.
Melgross, you should be ashamed of this behavior. You're so afraid of appearing to be wrong, that you've basically called a (hopefully) respected member a liar.
If I posted links to those definitions, would you admit that light has more than one definition? That it can refer to non-visible parts of the spectrum?
I'm saying that those snippets are not enough. please don't try to turn this into something it's not. If I gave those short definitions, you would have said the same. You've already accused me of several things in this conversation, and this one is VERY annoying.
If you're not happy, then I suggest you take it up with an admin, and have him look at all the posts between us.
It is interesting to note that you aren't willing to say "if you post links I'll admit to those definitions".
How many links to definitions will it take?
If those links are posted will you admit to being wrong? Or will you just claim that those dictionaries are wrong too?
But hopefully everyone else has been as entertained by this study in psychology as I have been. Really, the various definitions of "light" aren't that fascinating. What has interested me though is the culture of this board and how engaged some people are with not being wrong, myself included.
With that said, I'll bow out of sticking up for one of the above poster's valid use of the word light. I'll let Melgross have the last word in proclaiming the only definition of "light".
(Well, unless melgross walks into the trap of being willing to admit wrong when links are posted to dictionaries which have more than one definition of the word light. In which case, i'll return and post some links. Enjoy!
Those aren't snippets. Those are exact and entire definitions copy and pasted without any modification at all. What you're failing to grasp is that words have multiple definitions.
It is interesting to note that you aren't willing to say "if you post links I'll admit to those definitions".
How many links to definitions will it take?
If those links are posted will you admit to being wrong? Or will you just claim that those dictionaries are wrong too?
So, instead of arguing this, why then don't you post the links. Quite frankly, these don't look like entire definitions.
Dictionary.com: "a similar form of radiant energy that does not affect the retina, as ultraviolet or infrared rays."
American heritage: "Electromagnetic radiation of any wavelength."
Webster: "a form of radiant energy similar to this, but not acting on the normal retina, as ultraviolet and infrared radiation"
Those are full definitions? The first and last don't even look like complete sentences, or definitions. The middle one is clearly not complete, as no one would ever define light as "electromagnetic radiation of any wavelength.".
Here is the definition from Dictionary.com:
http://dictionary.reference.com/browse/light
I'll quote the definition further down which says Physics:
a. Electromagnetic radiation that has a wavelength in the range from about 4,000 (violet) to about 7,700 (red) angstroms and may be perceived by the normal unaided human eye.
b. Which you quoted, is derived from a. It doesn't include gamma rays. It doesn't include the radio spectrum. It doesn't include microwaves, and it doesn't include infrared or ultraviolet. It includes the visible spectrum from 400 to 700 nm, as I stated way back in the beginning.
So, no, what you quoted was NOT the full definition.
Now, should I look up the other ones as well?
Just to end this, if you really want me to, I'll grant you near infrared and near ultraviolet. Under certain limited circumstances, it MAY be considered to be light in some definitions. But not infrared and ultraviolet in their totality, as not even insects can see that far out.
If i post the links, will you admit to being wrong?
Edit: You posted one of the links for me. Look at definition 2b. It is exactly as I quoted.
So you're flat out calling me a liar. It's tough, but i'll refrain from rebutting.
If i post the links, will you admit to being wrong?
I'm not calling you anything. I simply posted the ENTIRE definition that Dictionary.com has for light, which is far longer than that one sentence you posted. I then showed where that sentence came from and what it means. Did you read that?
If you want to say that I CALLED you a liar, that's your concern.
I'd be delighted if you did post the other links, as you think you should. Just let's make sure it's understood how scientific definitions work. The definition of greatest meaning is written first, and the others are derived from increasingly smaller subgroups. They never contradict the previous definition. So if the first one says any number between 2 and 8, and the second said any number, it's understood to mean any particular number between 2 and 8.
In other words, "b" can never broaden the definition already set by "a".
If you want to argue that, then don't bother. This isn't a literary discussion
So, instead of arguing this, why then don't you post the links. Quite frankly, these don't look like entire definitions.
Those are full definitions? The first and last don't even look like complete sentences, or definitions. The middle one is clearly not complete, as no one would ever define light as "electromagnetic radiation of any wavelength.".
It's also on the wikipedia page on light:
"Light is electromagnetic radiation, particularly radiation of a wavelength that is visible to the human eye (about 400–700 nm, or perhaps 380–750 nm[1]). In physics, the term light sometimes refers to electromagnetic radiation of any wavelength, whether visible or not.[2][3]"
Reference 3 is:
http://books.google.com/books?id=Iry...age&q=&f=false
The phenomenon of emission of electrons from a metallic surface when illuminated by "light of appropriate wavelength or frequency is known as photoelectric effect.
Different substances emit photoelectrons when subjected to different radiations. For instance, X-rays incident on heavy metals eject electrons from K, L shells. Certain semi-conductors like transistors respond to infrared radiations. The alkali metals respond very well to visible and ultraviolet radiations."
But hey...what does the author of Comprehensive Physics know about light?
Here is the definition from Dictionary.com:
http://dictionary.reference.com/browse/light
I'll quote the definition further down which says Physics:
b. Which you quoted, is derived from a. It doesn't include gamma rays. It doesn't include the radio spectrum. It doesn't include microwaves, and it doesn't include infrared or ultraviolet. It includes the visible spectrum from 400 to 700 nm, as I stated way back in the beginning.
So, no, what you quoted was NOT the full definition.
No...b is not derived from a. It means that light also refers to radiant energy such as ultraviolet or infrared. In fact definition a) ALSO clearly indicates that light is "Also called luminous energy, radiant energy." and the definition of radiant energy is:
"radiant energy
–noun Physics.
1.\tenergy transmitted in wave motion, esp. electromagnetic wave motion.
2.\t light 1 (def. 2a)."
Now, should I look up the other ones as well?
Just to end this, if you really want me to, I'll grant you near infrared and near ultraviolet. Under certain limited circumstances, it MAY be considered to be light in some definitions. But not infrared and ultraviolet in their totality, as not even insects can see that far out.
Please. If the physicists refer to X-Ray light then full range of UV and IR counts.
"Swift-detected GRB080307 showed an unusual smooth rise in its X-ray light curve around 100s after the burst, at the start of which the emission briefly softened."
http://adsabs.harvard.edu/abs/2009MNRAS.395..328P
"Other examples of EM radiation are microwaves, infrared and ultraviolet light"
http://imagine.gsfc.nasa.gov/docs/sc...NRAS.395..328P
"We present a unified model of near infrared, optical, and X-ray light curves for V2491 Cyg,..."
Gee...three forms of light...including x-ray.
http://arxiv1.library.cornell.edu/abs/0902.2424
"The Advanced Light Source (ALS), a division of Berkeley Lab, is a national user facility that generates intense light for scientific and technological research. As one of the world's brightest sources of ultraviolet and soft x-ray beams--and the world's first third-generation synchrotron light source in its energy range--the ALS makes previously impossible studies possible."
http://www.als.lbl.gov/
"The Linac Coherent Light Source (LCLS) produces ultrafast pulses of X-rays millions of times brighter than even the most powerful synchrotron sources — pulses powerful enough to make images of single molecules."
http://lcls.slac.stanford.edu/
Gee...them physicists sure are dumb to call a linear accelerator a light source. They called them x-rays light where any damn fool knows if you can't see it, you can't call it light.
Another example where gracefully admitting you were wrong would have resulted in less embarrassment. 30 seconds of googling X-Ray and Light resulting in scads of hits from national laboratories calling their big assed accelerators and synchrotrons LIGHT SOURCES.
But obviously you have a better understanding of the word "light" than physicists.
"At the same time, customers in forums have helped one another by asking those with problems to take their Kindles into direct sunlight and hold it there for a minute or so, and to try a page turn with it while doing so. As with the Kindle 1, some units don't do well in direct sunlight, showing fading of fonts. Any such unit would be a defective one, which Amazon customer reps now recognize, and they will replace such units honoring the basic warranty with a 1-day shipment of another boxed Kindle 2. This has made a difference for those whose problems had more to do with something in the circuitry of some units."
"The official word from amazon cs was that faulty e-ink receptors in some of the first batch of kindle 2's were the source of the problem. It is a defect and the k2 is not supposed to do this so for those of you who haven't tested your device in sunlight you might want to look into it.'
http://kindleworld.blogspot.com/2009...-sun-test.html
Here's even a picture:
http://www.kindleboards.com/index.ph...html#msg116985
This affects some Sony ebooks too. Like this one:
http://www.mobileread.com/forums/att...5&d=1264529044
Personally, I don't read a lot in direct sunlight except at the beach. I'd rather take a paperback there than risk an expensive ebook. So for me LCD works better.
It's also on the wikipedia page on light:
"Light is electromagnetic radiation, particularly radiation of a wavelength that is visible to the human eye (about 400?700 nm, or perhaps 380?750 nm[1]). In physics, the term light sometimes refers to electromagnetic radiation of any wavelength, whether visible or not.[2][3]"
Reference 3 is:
http://books.google.com/books?id=Iry...age&q=&f=false
The phenomenon of emission of electrons from a metallic surface when illuminated by "light of appropriate wavelength or frequency is known as photoelectric effect.
Different substances emit photoelectrons when subjected to different radiations. For instance, X-rays incident on heavy metals eject electrons from K, L shells. Certain semi-conductors like transistors respond to infrared radiations. The alkali metals respond very well to visible and ultraviolet radiations."
But hey...what does the author of Comprehensive Physics know about light?
No...b is not derived from a. It means that light also refers to radiant energy such as ultraviolet or infrared. In fact definition a) ALSO clearly indicates that light is "Also called luminous energy, radiant energy." and the definition of radiant energy is:
"radiant energy
?noun Physics.
1.\tenergy transmitted in wave motion, esp. electromagnetic wave motion.
2.\t light 1 (def. 2a)."
Please. If the physicists refer to X-Ray light then full range of UV and IR counts.
"Swift-detected GRB080307 showed an unusual smooth rise in its X-ray light curve around 100s after the burst, at the start of which the emission briefly softened."
http://adsabs.harvard.edu/abs/2009MNRAS.395..328P
"Other examples of EM radiation are microwaves, infrared and ultraviolet light"
http://imagine.gsfc.nasa.gov/docs/sc...NRAS.395..328P
"We present a unified model of near infrared, optical, and X-ray light curves for V2491 Cyg,..."
Gee...three forms of light...including x-ray.
http://arxiv1.library.cornell.edu/abs/0902.2424
"The Advanced Light Source (ALS), a division of Berkeley Lab, is a national user facility that generates intense light for scientific and technological research. As one of the world's brightest sources of ultraviolet and soft x-ray beams--and the world's first third-generation synchrotron light source in its energy range--the ALS makes previously impossible studies possible."
http://www.als.lbl.gov/
"The Linac Coherent Light Source (LCLS) produces ultrafast pulses of X-rays millions of times brighter than even the most powerful synchrotron sources ? pulses powerful enough to make images of single molecules."
http://lcls.slac.stanford.edu/
Gee...them physicists sure are dumb to call a linear accelerator a light source. They called them x-rays light where any damn fool knows if you can't see it, you can't call it light.
Another example where gracefully admitting you were wrong would have resulted in less embarrassment. 30 seconds of googling X-Ray and Light resulting in scads of hits from national laboratories calling their big assed accelerators and synchrotrons LIGHT SOURCES.
But obviously you have a better understanding of the word "light" than physicists.
I've had enough physics to know what physicists mean by the word "light". Yes, even in textbooks there are errors. Unfortunately, sometimes we use terms that we don't mean the way we say them. I've used the term infrared light too, even though I know it's incorrect, simply because it's heard so often it isn't thought about. The first reference, using the proper definition is still the correct one. The term "light year" for example is used to mean the distance ANY electromagnetic wave travels in a year, just because all of then travel at the speed of "light". It doesn't mean that physicists think that all of the spectrum is "light". And, so, yes, words seep into texts that don't belong there. We've all had texts where that has happened. It doesn't change things.
Don't be funny. LED is a categorical definition of a process defined device. If you don't know that then don't bother. The LED was invented a long time ago, well before the infrared version came on the scene. You might as well use the heat lamp, which produces mostly infra red, as a light to read by, with its leakage of some visible spectrum and call it a reading light.
There's not much more point to this.
Geez...wrong again.
"In 1961, experimenters Robert Biard and Gary Pittman working at Texas Instruments,[11] found that GaAs emitted infrared radiation when electric current was applied and received the patent for the infrared LED.
The first practical visible-spectrum (red) LED was developed in 1962 by Nick Holonyak Jr., while working at General Electric Company.[2] "
The IR LED preceded the visible light LED.
From the Wikipedia LED entry. The original source is this:
"The first LEDs were infrared (invisible)."
http://invention.smithsonian.org/cen...ors/biard.html
Geez...wrong again.
"In 1961, experimenters Robert Biard and Gary Pittman working at Texas Instruments,[11] found that GaAs emitted infrared radiation when electric current was applied and received the patent for the infrared LED.
The first practical visible-spectrum (red) LED was developed in 1962 by Nick Holonyak Jr., while working at General Electric Company.[2] "
The IR LED preceded the visible light LED.
From the Wikipedia LED entry. The original source is this:
"The first LEDs were infrared (invisible)."
http://invention.smithsonian.org/cen...ors/biard.html
It did not. The discovery of LEDs took place in an experiment that had nothing to do with that idea. If you want to get technical:
http://en.wikipedia.org/wiki/H._J._Round
It did not. The discovery of LEDs took place in an experiment that had nothing to do with that idea. If you want to get technical:
http://en.wikipedia.org/wiki/H._J._Round
Yes, the physical effect was noted long before someone actually invented usable LEDs.
However, the IR LED patent preceded visible light LED patent by a year. Therefore the IR LED invention preceded the invention of visible light LEDs. Both are LIGHT emitting diodes by the way.
Or were you being imprecise and using the term "invented" vs "discovered"? Or more likely just wrong again?
I've had enough physics to know what physicists mean by the word "light". Yes, even in textbooks there are errors. Unfortunately, sometimes we use terms that we don't mean the way we say them. I've used the term infrared light too, even though I know it's incorrect, simply because it's heard so often it isn't thought about. The first reference, using the proper definition is still the correct one. The term "light year" for example is used to mean the distance ANY electromagnetic wave travels in a year, just because all of then travel at the speed of "light". It doesn't mean that physicists think that all of the spectrum is "light". And, so, yes, words seep into texts that don't belong there. We've all had texts where that has happened. It doesn't change things.
So you're saying that when they named the Advanced Light Source and LCLS these physicists were dumber than you and didn't know the meaning of the word light? Because you took a physics class?
Whatever. Getting you to admit you're wrong about anything is like tilting at windmills. Not even the full quotes you demanded changes anything. Instead all of those people are incorrect in their usage of the term light because you say so.
Has it ever occurred to you that the term "visible light" itself is an indicator that there is "non-visible light" and is not a tautology? If the term light ONLY ever referred to the EM spectrum that can be seen by the human eye the "visible" adjective need never be applied? And certainly not so widely applied?
That when top physicists refer to IR light or UV light that they aren't being imprecise? But maybe applying a different adjective to describe a specific form of "light" and that the term light can be applied for the entire EM spectrum because hey...they're all just photons with different energy levels?
Nah...that could NEVER be.
Oh...and learn to use the dictionary. Your Merriam Webster definition supports dfiler and not you.
"c: electromagnetic radiation of any wavelength that travels in a vacuum with a speed of about 186,281 miles (300,000 kilometers) per second; specifically : such radiation that is visible to the human eye"
http://www.merriam-webster.com/dictionary/light
The "specifically" term means:
"The sense divider specifically is used to introduce a common but highly restricted meaning subsumed in the more general preceding definition:
pon·tiff . . . noun . . . 2 : BISHOP; specifically, often capitalized : POPE 1
http://www.merriam-webster.com/help/dictnotes/def.htm
Meaning that the Pope is a COMMON meaning of pontiff (because he's the bishop of Rome) but not the ONLY meaning and there is a more GENERAL definition that PRECEDES it (bishops in general are pontiffs).
So one GENERAL definition of light is electromagnetic radiation of any wavelength.
Further the "c" indicates a SUBSENSE, and is not predicated on the previous SUBSENSES. They are separate but related meanings of the term.
"The system of separating the various senses of a word by numerals and letters is a lexical convenience. It reflects something of their semantic relationship, but it does not evaluate senses or set up a hierarchy of importance among them."
Senses and subsenses are semantically related...not semantically dependent. The "job" example in that same area shows this.
"At job the date indicates that the earliest unit of meaning, sense 1a, was born in the seventeenth century, and it is readily apparent how the following subsenses are linked to it and to each other by the idea of work. Even subsense 1d is so linked, because while it does not apply exclusively to manufactured items, it often does so, as the illustrative quotation suggests."
1d is not ALWAYS linked to previous related historical meanings of the word (1a - 1c). it is grouped because it is OFTEN related.
http://www.merriam-webster.com/help/dictnotes/def.htm
So none of your sources supports your assertion but clearly says the opposite.
Yes, the physical effect was noted long before someone actually invented usable LEDs.
However, the IR LED patent preceded visible light LED patent by a year. Therefore the IR LED invention preceded the invention of visible light LEDs. Both are LIGHT emitting diodes by the way.
Or were you being imprecise and using the term "invented" vs "discovered"? Or more likely just wrong again?
I'm not wrong either time. What I should have said was that it was known first. The term invented becomes sticky when something is known a long time before.
So you're saying that when they named the Advanced Light Source and LCLS these physicists were dumber than you and didn't know the meaning of the word light? Because you took a physics class?
Whatever. Getting you to admit you're wrong about anything is like tilting at windmills. Not even the full quotes you demanded changes anything. Instead all of those people are incorrect in their usage of the term light because you say so.
Has it ever occurred to your that the term "visible light" itself is an indicator that there is "non-visible light" and is not a tautology? If the term light ONLY ever referred to the EM spectrum that can be seen by the human eye the "visible" adjective need never be applied? And certainly not so widely applied?
That when top physicists refer to IR light or UV light that they aren't being imprecise? But maybe applying a different adjective to describe a specific form of "light" and that the term light can be applied for the entire EM spectrum because hey...they're all just photons with different energy levels?
Nah...that could NEVER be.
Oh...and learn to use the dictionary. Your Merriam Webster definition supports dfiler and not you.
"c: electromagnetic radiation of any wavelength that travels in a vacuum with a speed of about 186,281 miles (300,000 kilometers) per second; specifically : such radiation that is visible to the human eye"
http://www.merriam-webster.com/dictionary/light
The "specifically" term means:
"The sense divider specifically is used to introduce a common but highly restricted meaning subsumed in the more general preceding definition:
pon·tiff . . . noun . . . 2 : BISHOP; specifically, often capitalized : POPE 1
http://www.merriam-webster.com/help/dictnotes/def.htm
Meaning that the Pope IS a pontiff, and a COMMON meaning of pontiff but not the ONLY meaning and there is a more GENERAL definition that PRECEDES it.
So the GENERAL definition of light is electromagnetic radiation of any wavelength.
Further the "c" indicates a SUBSENSE, and not predicated on the previous SUBSENSES. They are separate but related meanings of the term.
"The system of separating the various senses of a word by numerals and letters is a lexical convenience. It reflects something of their semantic relationship, but it does not evaluate senses or set up a hierarchy of importance among them."
Senses and subsenses are semantically related...not semantically dependent. The "job" example in that same area shows this.
http://www.merriam-webster.com/help/dictnotes/def.htm
So none of your sources supports your assertion but clearly says the opposite.
I give up. As you know, My physics background is much more than " a physics class". But you have none.
In the case mentioned, by the way, "specifically" means accurately. That's also from Mirriam-Webster.
Oh, forget it.
I give up. As you know, My physics background is much more than " a physics class". But you have none.
In the case mentioned, by the way, "specifically" means accurately. That's also from Mirriam-Webster.
Oh, forget it.
Jeez, you wont even accept what the dictionary says what it means when it uses a term? Those aren't random definitions of the word but the INSTRUCTIONS ON HOW TO USE THE DICTIONARY FROM THE DICTIONARY ITSELF.
You want to forget it because you're completely wrong and simply refuse to admit it. Again.
Jeez, you wont even accept what the dictionary says what it means when it uses a term? Those aren't random definitions of the word but the INSTRUCTIONS ON HOW TO USE THE DICTIONARY FROM THE DICTIONARY ITSELF.
You want to forget it because you're completely wrong and simply refuse to admit it. Again.
I'm going to let you feel good, and stop posting on this. but if you don't I will delete them
This topic is ended.