Eise

On 09/02/2018 at 8:07 AM, Eise said:

Then you must conclude that the daily use of 'seeing', in the sense of 'seeing houses, cars and apples' is the wrong meaning.

This is what you said:

On 08/02/2018 at 11:00 PM, koti said:

All we can see is light - nothing less, nothing more - only light.

What you were describing ('you see only light') fits to my description of 'see2'. With that 'only' you exclude 'see1'.

I put it in your mouth ('Then you must conclude...'), not in mine. I would never agree with your statement that we only see light. Usually I see all kind of things, thanks to their reflection. I see cups on my desk, which I see of course too, my computer screens (OK, these emit light), outside I see cars. If you say we only see light, i.e. 'seeing light' is the only correct use of 'seeing', then you should say I am wrong when I describe my environment, and I should use another word instead of 'seeing', e.g. 'observe by visually means'. But that would be a bit weird, isn't it?

And we had the problem of the 'perfect black dog'. As it neither reflects, nor emits light, one had to say one does not see this dog. Which makes no sense too.

20 minutes ago, Area54 said:

Eise appears to say that "you" must conclude the daily use of 'seeing', in the sense of 'seeing houses, cars and apples' is the wrong meaning. He does not say that he concludes this.

Started posting before I saw yours. Yep, that is exactly what is going on.

39 minutes ago, koti said:

Since you assert that the use of the word "seeing" is wrong,

I did not do that. I distinguished two different meanings, repeatedly saying that in daily use this distinction plays no role. But of course, when somebody reduces the meaning of 'seeing' to only one of these two meanings, he necessarily leaves out the other. That is e.g. what the OP did. Nowhere I said that saying 'I see light' is wrong. But what I did say is that 'I see1 light' is wrong, because we do not see light because it reflects light. 

13 minutes ago, koti said:

you state that Im using your definitions

Yes, you did: See1 = See2. 

I think the only argument against my distinction is that it is practically useless. That's fine. But it does not really help to answer the OP.

Do you think we disagree on semantics or on physical processes? When it is semantics, how would you flesh out these semantic differences? 

46 minutes ago, koti said:

Cute strawman Eise. I thought you were better than that. 

Explain why this would be a strawman. You use my definitions. How else should I understand this?

52 minutes ago, Area54 said:

That made me wonder, can we feel touch?

That is not the same, that is a pleonasm. Something like 'it costs expensive': one should say 'It is expensive' or 'it costs much'.

52 minutes ago, Area54 said:

I incline to CharonY's remark that this is a semantic debate

Yep. 

15 hours ago, John Cuthber said:

Nobody said that, and you should know better than to try a strawman attack.

This is what Koti said:

19 hours ago, koti said:

See1 = See2

These are my definitions. And see2 means 'seeing because it enters the eye', which of course is only valid for light. So it is not a strawman at all: it is a conclusion following from the definitions of see1 and see2 and Koti's proposition that these are the same.

15 hours ago, John Cuthber said:

Congratulations, you have demonstrated that a car is not the same as light.

Thank you. But saying of two things they are the same (or not) is always under a point of view. The point of view here is how we see things. We see cars because they reflect light, and we see light because it enters the eye. That is the difference this thread is about.

15 hours ago, John Cuthber said:

Now all you need to do is find someone who was wondering about that question.

Just the OP. Nothing more. You can google yourself. You will find some similar questions and reactions.

15 hours ago, koti said:

The question whether light is visible or invisible is trivial. On top of it the above contains a false premise that "we never see the actual light"

Well, yes, more or less. But the OP noticed a difference between how we see light and how we see macro objects.

15 hours ago, dimreepr said:

It's a boolean question, what's to clarify? 

That only two answers are possible, does not necessarily mean that the question is easy. And many posters here answered with 'it is a question of semantics', or 'depends on how you define seeing' (not just me!) So even if a question has yes/no character, it does not mean that one of these answers suffices. To give a terrible example: 'do humans have free will?' It is a yes/no question, but discussions about it are furious. Still appearing books and articles about it. And the answer might in the first place be the same as here: 'it is a question of semantics', or 'depends how you define free will'.

Examples:

On 22/02/2016 at 6:46 PM, swansont said:

So a lot of this depends on what you mean by "seeing" light.

On 26/01/2018 at 8:41 PM, studiot said:

I agree we need a working definition of seeing and in order to have that we need a working model of the process

On 26/01/2018 at 10:19 PM, MigL said:

Maybe we need to define what visible and invisible means instead.

On 27/01/2018 at 9:19 PM, MigL said:

everything else is semantics.

On 28/01/2018 at 2:52 PM, swansont said:

Slippery and especially so when nobody defines their terms.

On 29/01/2018 at 12:02 PM, swansont said:

Depends on how you've defined the terminology. (...) Stop pretending that everyday language has such precise definitions. It doesn't.

1 hour ago, koti said:

. I just don’t see the alternative definition of „see” which you are trying to convey here.

I am not trying to to convey a new definition. I try to clarify the question of the OP.

31 minutes ago, koti said:

That's not a valid question in my opinion.

Why?

I don't think so. The answer of course is 'no'. But light you see when it enters your eye.

3 hours ago, John Cuthber said:

Once again- since you can see light, it's visible and there's nothing more to say about it.

If you want. 

33 minutes ago, koti said:

See1 = See2

You see a car because it enters your eye?

34 minutes ago, koti said:

In fact there is only one „see”

I see.

4 hours ago, BahadirArici said:

False. Scvientific methodology is a methodology. When you devolop a hypotesis you may not even know if it is testable. 

True. Seldom, but true. But if you know in advance that an empirical test will be impossible, then it makes really no sense anymore. Then it becomes a pure question of opinion. You can tell why you think that heaven is as you think, it could even be a rational discussion (i.e. you give arguments for your opinion), but it would never be scientific, because the absolute touchstone is missing: empirical reality.

21 minutes ago, John Cuthber said:

If we change the meanings of words then we can make anything "true", but it isn't helpful. 

I agree with that. But I only fleshed out that there is a physical difference between seeing macro objects and seeing light. For the first I need light (by reflection or by the macro object emitting light itself), for the second other light is not useful to see it, and light also does not emit light. Both processes are described by the same word 'seeing'. So the meanings are there, in the daily use of the word. I did not add a completely new meaning. I just made an artificial distinction between these two meanings. In this light it is possible to understand and react on the OP. You can be sure, without such questions as in the OP, I never make this distinction.

26 minutes ago, John Cuthber said:

If we stop using  words for their "accepted" uses then fish handstand juice blue circuit.

You take the words from my mouth...

1 hour ago, BahadirArici said:

You can dissscuss a none-scientific subject with quite scientific methods, my friend. 

No, you can't. 'None-scientific' practically means that scientific methods do not work, otherwise we would have made a science from it.

12 hours ago, John Cuthber said:

For the sake of simplicity, I'm ignoring scattering of light by air.

Yes, please. Otherwise I must pump out all the air from the room, and put you into a astronaut suit...

12 hours ago, John Cuthber said:

That's the same issue as the coast of China. I can't see it because I'm not in the right place so I'm not looking at it. Obviously, I need to clarify what that means for you.

There is no pathway for light from the coast of China to reach my eyes (because there is stuff in the way) and there is no way for light from the laser to reach my eyes (because it's going in the wrong direction..

If you were as close to China's coast as to the laser, you would surely see it. But you see1 the coast, but you do not see1 (or see2!) the laser beam in the room.

12 hours ago, John Cuthber said:

I guess you can call that semantics, but only if you more or less ignore the accepted definition of the words.

I already said a dozen times that the distinction is pretty artificial.

12 hours ago, John Cuthber said:

(you sometimes choose to put numbers on the word "see" to show that- like many English words- it has slightly different meanings depending on context)

Exactly. So we agree that 'to see' has slightly different meanings. Then why do you not agree that if we rigorously distinguish the two meanings, reduce the meaning to only one of them (see1 = seeing macro objects because they reflect or emit light), that it does not apply to light itself (see2 = seeing light because it enters the eye).

But we can go on endlessly. If you still do not agree, I think we should agree to disagree.

1 hour ago, BahadirArici said:

If there were heaven, how would it be? A science minded person can handle an if sentence, i asume?

Of course:

Premise: If there were heaven, how would it be.

Fact: Heaven was never observed.

Conclusion: we do not have to ask the question 'how would it be'.

That is an example how we, science minded persons, handle if-sentences.

1 hour ago, BahadirArici said:

And i do think we should be able to talk about afterlife with science-minded people as with everyone else.

No. Science per definition is rooted in empirical reality, which we can intersubjectively share. However, in the case of heaven we do not have such an empirical root. We have no observations about heaven, even no reason to think it exists at all.

So, now I, a science minded person, have talked about heaven. So you can talk about it, but the discussion is rather short. 

On 09/02/2018 at 6:08 PM, CharonY said:

The discussion goes in circles because it is down to semantics.

That really seems the case. The problem that I seem to have, is that it looks like I am presenting some alternative physics. I don't. 

On 09/02/2018 at 6:08 PM, CharonY said:

But if we wanted to make a distinction, we could.

Exactly. That is all I am pointing out: that one can make this distinction. Not that one should. 

Hi John,

Let's make an example again. You are standing in a totally dark room with an absolute black wall, the air is dry and there is no dust. There are two dividers in the room, leaving an opening. Behind the left divider stands a laser, behind the right divider stands an absolute black absorber to which the laser light is directed. No light is leaking out. Behind the opening also stands a chair.

Now you stand in front of the opening:   

                       chair
                                         x
     Laser --->                       absorber
                                         x

xxxx Divider xxxxx              xxxxx Divider xxxxxxx





                      you

Do you see the laser light?

Now you take a flash light, and shine it through the opening. You see the chair, but do you see the laser light? Can you see the laser light in this situation? So is light visible if you look at it? ('At it' is not the same a looking into the beam). 

2 hours ago, koti said:

In fact it would be a ridiculous conclusion, we see macro objects (or any other object) only due to light emitting or reflecting off of them and  there is no other means of seeing for humans. That is the only meaning of „seeing”, there is only one way of „seeing” for humans.

But this implies again that we do not see light... Really, the only way out is to acknowledge that the word 'seeing' has two meanings (at least).

We both say 'I see an apple' and 'I see light', but the process as a whole is not the same. In the first case reflection is necessarily involved, in the second it isn't. But don't you agree that is just a question of semantics? Do you think we disagree on any physical process involved in seeing?

15 hours ago, Itoero said:

I mean there is no set definition. Most nouns have definitions. I agree with the Wikipedia-definition: Philosophy (from Greek φιλοσοφία, philosophia, literally "love of wisdom") is the study of general and fundamental problems concerning matters such as existence, knowledge, values, reason, mind, and language.

You said philosophy is not defined:

On 31/01/2018 at 5:21 PM, Itoero said:

That's just an opinion, it's not defined  what philosophy is.

So you are saying:

• We do not exactly agree on what philosophy is
• But science is a subfield of it.

Well it is my opinion that, whatever philosophy is, it is not empirical science. I've studied both, and I can tell you, philosophy and empirical science are very different.

Interesting enough your Wikipedia quote does not list 'empirical reality' as one of the matters with which philosophy is concerned.

And before you come with cosmology as part of metaphysics, and metaphysics being a part of philosophy: today this is just not true anymore. Cosmologists are not necessarily metaphysicians anymore.

16 hours ago, Itoero said:

That's new. I thought hypotheses demand empirical evidence to be scientific. 

Great, then you have learned something. Strange is completely right. A hypothesis is scientific, if it has empirical consequences, and is consistent with established scientific facts.

A scientific hypothesis can be:

• Wrong, when the empirical consequences cannot be confirmed (Strange's examples: steady state theory, phlogiston, the aether)
• Correct (at least for the moment) when the empirical consequences are confirmed
• Open, when the empirical consequences are not tested (yet).

It is true that scientific hypotheses demand empirical evidence. But that is because we want to know if the hypotheses are correct.

10 hours ago, John Cuthber said:

I presume you don't, because you are steadfastly ignoring the fact that- in this thought experiment, without my glasses I don't see any goddamned apple.

Ah, Really missed that. Just to be sure that I understand you: the Enterprise is flying in your direction, and without glasses you are seeing badly. So what do you see1: a blurry blue object. And that is because you see2 blue light. (I know what I am saying: I have glasses since primary school...).

You are also consistently ignoring the fact that seeing macro objects is a different process as seeing light. It seems to me you are arguing that only see2 counts as seeing. But that doesn't fit to the daily use of the word 'seeing', in which we most of the time talk about seeing macro objects.

8 hours ago, John Cuthber said:

Nice strawman.

Light is a thing.

So "light" is a subset of "things".

If I had said that light was a "macro object" - whatever that may be- you would have a point.

I always meant macro objects when I wrote about 'things'. But if you want, I am flexible. So slightly different:

We have the set of things. Now one can divide this set in subsets based on all kind of differences. One difference: there are things we see can because they reflect light, e.g. cars, houses and apples. On the other side there is one thing we can see because it enters the eye: light.  The first category we can see1, the second category we can see2. (Didn't you say somewhere that 'we only see light'?)

23 hours ago, Eise said:

Do they mean exactly the same with the words 'see'?

8 hours ago, John Cuthber said:

Nobody said they did.

Then why do you have so much trouble that I clearly distinguish between the two meanings???

8 hours ago, John Cuthber said:

However, both are legitimate uses.

Of course. I repeatedly said it: no serious, real problem is solved by making this distinction. But one can make this distinction, and again, when somebody explicitly asks the question if light is visible, it should immediately ring a bell that this difference in use exists. So the correct way to answer such a question is to point to the two different uses of the word 'seeing', and that the answer depends on which meaning you give to the word seeing. If you imply both, then of course you see light and macro objects.

And again you are contradicting yourself: on one side you argue that we only see light; on the other you say that both meanings are legitimate. So what is it?

9 hours ago, koti said:

All we can see is light - nothing less, nothing more - only light.

Then you must conclude that the daily use of 'seeing', in the sense of 'seeing houses, cars and apples' is the wrong meaning. Say the OP would have asked if it is true that we cannot see macro objects, would you have agreed with him, because we in fact only see light?

On 08/02/2018 at 8:29 AM, Eise said:

Again: it is obvious that we all agree on the physical basis of seeing macro objects on the one side, and light at the other side. If we see light, it means the light enters the eye. If we see macro objects, the objects do not enter our eye. On the other side: we see cars because they reflect light, but we cannot see light that does not enter the eye, light does not reflect or emit light. Do we agree so far?

9 hours ago, koti said:

No, I disagree with the above, it is wrong

I only described physical facts here. So what is wrong?

On 02/02/2018 at 7:55 PM, John Cuthber said:

The idea of you telling me what I see is absurd- especially when I already told you.

To come one time back to this: with the blue apple/light you are not describing something you really have experienced. You are describing a thought experiment. And with thought experiments everyone can look if he agrees with the ideas about the occurrences that are described. I am criticising your thought experiment, more or less based on the fact that you are begging the question. You get out what you put in. The relativity aspect does not add anything to the discussion. You just argue that the only correct meaning of 'seeing' is 'seeing2', seeing light. But that is already a presumption you put in yourself. And it does not fit our daily use of language where we also see cars, tables and houses.

On 05/02/2018 at 2:53 PM, koti said:

I think this is faulty logic Eise. Technically, in the context that we are speaking here, cars that we see are light because they reflect light therefore we see them. If they wouldn't reflect light we wouldn't see them. It's crude and simple and I'm sure I don't need to explain this but that's really all there is to it.

'Cars are light?'. Now that sounds like faulty logic to me. 

Again: it is obvious that we all agree on the physical basis of seeing macro objects on the one side, and light at the other side. If we see light, it means the light enters the eye. If we see macro objects, the objects do not enter our eye. On the other side: we see cars because they reflect light, but we cannot see light that does not enter the eye, light does not reflect or emit light. Do we agree so far?

Now my position is that this difference in meaning of 'seeing' does not create any problem: not in daily life, not in science, and not in philosophy. So it really is a futile discussion. But: when somebody explicitly asks if light is visible, and even shows his assumption behind the question, it is time to realise that there is a physical difference between seeing macro objects and light. And a possible answer would be 'Well,  in the sense of ... of seeing, one could say light is invisible'. But immediately add that this is a bit artificial distinction, because we all know what somebody means when he says he is seeing light. 

On 05/02/2018 at 2:58 PM, StringJunky said:

We see a configuration of the light that represents the object the photons interacted with.

Yep. That is also an interesting way of describing the difference. We can make this representation, because light enters our eyes from different directions of the macro object, and our brain constructs this representation from it, unconsiously (we do not have to think "oh, all this light, let's calculate if the light was reflected by some object. Aha, all that light is reflected by a single object! It's a car!").

On 05/02/2018 at 11:14 PM, John Cuthber said:

You see cars because they reflect light and you see that light

You realise that use the word 'see' twice in this sentence. Do they mean exactly the same with the words 'see'?

On 05/02/2018 at 11:14 PM, John Cuthber said:

I don't see a goddamned apple.
And there is no blue apple for me to see.

See my remark about thought experiments above. You see a blue apple, even if the apple in its rest frame is red. 

On 05/02/2018 at 11:14 PM, John Cuthber said:

Except that "light" is a subset of "things".

Light is not a macro object. I very clearly made this distinction. But for the sake of argument: what does 'being a subset' mean?

It means that every attribute that applies to the superset, also applies to the subset. Now an attribute of macro objects is: can be seen by shining light on it. But this does not work for light. So light is not a subset of macro objects (even in this context).

On 03/02/2018 at 1:19 AM, John Cuthber said:

The only thing you see is light.

Then you cannot see cars, because cars are not light.

On 02/02/2018 at 7:55 PM, John Cuthber said:

The idea of you telling me what I see is absurd- especially when I already told you.

And it is still wrong. You see an apple: but for you it looks blue. So you see1 a  blue apple. Of course this is because you see1 the apple because you see2 blue light. And you might guess well that this is due to the Doppler-effect, especially while Scotty's T-shirt looks blue to you too. But nothing in the blue light alone will give you a clue that the light is Doppler-shifted.

On 02/02/2018 at 7:55 PM, John Cuthber said:

I may mistakenly believe that I see a blue apple. That's faulty perception. A bit like you "see" a line as longer than another line in optical illusions.

Literally it is not faulty. As I said, there is objectively no preferred observer frame. Of course it is easiest always to take the restframe of the object under scrutiny and you, the observer, as preferred frame. But when there is no such frame, because the frame move against each other, who is right? 

Seeing things and seeing light are just different things. And when one reduces the meaning of 'seeing' to 'seeing things', then you cannot see light. And when you reduce seeing to 'seeing light' only, then one cannot see things that reflect light. And if you use both meanings for seeing in one word, then you do not account for the difference between how we see macro objects and light. Which nearly never is a problem...

Quote

Light: visible or invisible?
I have a question about light. We all know that we see objects because they reflect light into our eyes. But we never see the actual light. So my question is why can't we see light. Or can we in fact see light. If so, how?

1 hour ago, studiot said:

Let me remind you of the OP.

I have this in mind all the time. Let's just look at the assumption behind the question 'Light: visible or invisible?' It is obvious: the OP's assumption is that we can see objects because they reflect light. If this would be the only meaning of seeing, then light really is invisible. You cannot see light that does not enter your eye, because light does not reflect light. (The same for emitting light: a light beam passing by does not emit light to your eyes. Therefore you cannot see light that does not enter your eyes).

But I surely agree with you that it is a rather limited concept of seeing, because we are also used to say that we see light. We perfectly understand when somebody says he is seeing light. As you say, it has multiple meanings. But in the strict sense that the OP is using (seeing1), we cannot see light. In the normal daily sense, of course we can see light (see2). And mostly we do not bother about this distinction, because it seldom leads to confusion. 

Except you meet a  philosopher in a thread about the visibility of light...

31 minutes ago, Tub said:

Would it help to clear away the semantics roadblock if we used " sense " instead of " see "?  So we can " sense " visible light, but we can't " sense " invisible light.

One could do that. Your 'sensing' however would be the same as my seeing2. But if you do not introduce a different concept for 'seeing1' the confusion will continue. One should exclude the meaning of 'sensing' from 'seeing'. To clear this up I am using 'seeing1'.

Your use of the concept 'semantics roadblock' is interesting. If one wants to try confusions as illustrated in this thread, one should be prepared to introduce new concepts for words, making them more precise, and sometimes introduce new ones. But obviously the resistance against such semantic moves is very strong. A semantic roadblock, as you say.

19 minutes ago, Strange said:

That seems to open a whole new can of worms.  For example, we can sense infrared but can’t see it. And what, exactly, does “sense” mean?

Yep. Therefore I introduced non-existing words: see1 and see2.

1 hour ago, John Cuthber said:

There isn't a blue apple in the universe- so that's obviously not what I am seeing.

Wrong. You see1 a blue apple. Only observers in the same inertial frame see1 the apple red. There is no objective reason to say that some inertial frame is preferred above another.

So once again: do you see3 the difference I make between seeing1 and seeing2? 

And do you see3 that there is a difference between seeing light and seeing objects by means of light?

14 hours ago, studiot said:

Just because you can't see it does not mean there is no problem.

Oops, that would be see3... 

14 hours ago, studiot said:

If the OP premise that light itself cannot be seen is true,

then how can you see the yellow light?

You don't see1 yellow light. You see1 a bright yellow tube. I think that if you want to have a clear discussion, you must distinguish between seeing1 and seeing2 (forget about seeing3...). As long as you mixup the two, we cannot have a clear discussion.

15 hours ago, studiot said:

How do you know there is yellow light and that it is yellow, if you can't see it?

I see1 the yellow tube, because I see2 its yellow light.

15 hours ago, studiot said:

Of course if you think the OP premise is untrue then that's fine, but what makes your version any better than any one else's?

That it accounts for the difference how we see macro objects (that do not need to enter the eye to see them: we see them by the light they reflect or emit), and how we see light (because it enters the eye). Do you see this difference, and do you see how I use the words 'seeing1' and 'seeing2' to account for this difference?

13 hours ago, swansont said:

IOW, it's semantics, as several of us have said.

Put another way is we don't see an image of light, as we see images of objects. But not everything we see is an object, so that can't be the entirety of the definition.

Exactly. But if you want to distinguish between these 2 ways of seeing, then one make such a (artificial, I fully agree) distinction. As it solves no real physical or philosophical problem, it is of course an empty intellectual exercise.

10 hours ago, John Cuthber said:

I checked with Captain Kirk. The colour of the apple didn't change; it still matches Scotty's shirt..

Yes. Kirk sees both still red. But you see1 Scotty's shirt and the apple both blue. Really, tell me what you see. And I am sure: you see a blue shirt and a blue apple.

10 hours ago, John Cuthber said:

The trouble is that they are not two things; they are one thing which is- in your explanation- simultaneously blue and yellow.

But you see them thanks to two different processes. But both fall under the definition of see1. When the lamp is turned on, you just see2 no reflected light anymore, you see2 yellow light. So you see1 a bright yellow lamp.

Don't you see that seeing light and seeing macro objects are not the same? 

10 hours ago, John Cuthber said:

At best all this shows is that whether or not you can see light is a matter of what you mean by "see".

Yep. That's the whole point. 

10 hours ago, John Cuthber said:

Whatever version of "see" you use; you can see light.

But that is wrong again, and inconsistent with the sentence I quoted from you above.

'Seeing' in daily life includes both meanings. And then of course it is at least very funny when somebody reduces the meaning to seeing1, and therefore concludes that light is invisible. And then furiously arguing that seeing1 is the only correct meaning of seeing.

I hoped that distinguishing between both meanings would clarify the discussion, but obviously that did not work... 

So once again: do you see3 the difference I make between seeing1 and seeing2? 

And do you see3 that in daily life we do not make this difference, and so we can see things, but also light.

23 minutes ago, studiot said:

John's point is: If a blue source is emitting yellow light how can you see the yellow light itself if you can't see light?

 I do not see a problem. Seeing1 is by means of reflecting light by an object, or by emitting light by an object. Sodium vapour is blue when it reflects light, and it is yellow when it emits light. In both cases you see1 a glass tube. Of course, you must see2 ('detect') the light to see1 the street lamp.

But this is of course all very artificial...

15 minutes ago, studiot said:

ohn asked a very good question about sodium, although this situation also applies to other materials.

Sodium is a greyish/white/silver metal as a solid, but in the gaseous phase it is blue if illuminated with ordinary light.

Under these conditions it does not give off any yellow light.

If the blue gas is then stimulated with electricity it then also gives of yellow light.

We no longer see the blue (although it must still be there) only the yellow.

But the sodium gas itself remains blue.

So we are seeing yellow light emitted by blue objects as a result of some electrical process.

Ok, this is what John said:

17 hours ago, John Cuthber said:

As I pointed out , the sodium vapour in a street lamp is blue, but what you see is yellow.
So the yellow you see isn't the "source", it's the light you see..

What you see1 are two different things:

- a street lamp with a blueish content, by means of reflecting light

- a street lamp with a bright yellow content, by means of emitting light

But of course you see2 blue light in the first case and yellow light in the second case.