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The Contender
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Water is not really blue

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Voting Style: Open with Elo Restrictions Point System: 7 Point
Started: 11/10/2015 Category: Places-Travel
Updated: 10 months ago Status: Post Voting Period
Viewed: 997 times Debate No: 81883
Debate Rounds (4)
Comments (25)
Votes (0)




Good morning DDO. This debate is for Cobalt.


1. No
2. No trolling
3. Over 2500 ELO to vote
4. Over 2500 ELO to accept
5. If you don't follow these rules, the opponent wins the debate.


Resolved: Water is not really blue

Pro: fire_wings
Con: Opponent


1. Acceptance

2. Arguments
3. Rebuttals
4. Conclusion

No arguments in first or last round.


1. Water: the liquid that has no taste, or smell, that falls from clouds as rain, that forms streams, lakes, and seas, and that is used for drinking, washing, etc.

2. Blue: A color, one of the four main colors. Color between Violet and Green.

Thank you.




Thank you.


Sorry for that bit of trouble in the comments -- I just wanted to make sure that we are going off definitions that are as accurate as possible.

I accept this debate and I look forward to the first round of argumentation!
Debate Round No. 1


Thank you for your acceptance Cobalt. I will go on my arguments first then it is your turn.


The debate is about whether or not water is actually blue or not. In this debate, we can argue about the definitions, make scientific reasons and not just our own explanations, and science related sources. If I give scientific reasons of why water is not blue and then I fill the BOP, I win. If my opponent gives scientific reasons why water is blue, she will win the debate. This debate needs scientific reasons because this debate is a science debate and if we do not give real facts if water is not blue, there is no evidence so we need proof. That is why even though there is some plagiarizing, if we give proof of science, it is okay. However do not copy-paste the whole thing. This means that you do not know any explanations.


1. Water is clear.

Okay, my first argument is that water is clear. This is a science fact. This follows with the resolution. The resolution is water is not really blue. It is clear. There is scientific facts of this one.

Okay, first of all water is clear. Many people think that water is clear because in the ocean or any kind of river, water looks blue. However this is false. Water is actually clear.

There is a scientific reason that shows that water looks blue. It is all because of the sky.

Why the sky?

The sky is blue. That is a fact. The thing is that all the oceans and the rivers, above them is the sky. It reflects the blue color down, which is to the water, which is clear. This means that the water being blue is a reflection. It is actually clear.

"The ocean looks blue because red, orange and yellow (long wavelength light) are absorbed more strongly by water than is blue (short wavelength light). So when white light from the sun enters the ocean, it is mostly the blue that gets returned. Same reason the sky is blue."

In other words, the color of the ocean and the color of the sky are related but occur independently of each other: in both cases, the preferential absorption of long-wavelength (reddish) light gives rise to the blue. Note that this effect only works if the water is very pure; if the water is full of mud, algae or other impurities, the light scattered off these impurities will overwhelm the water's natural blueness. This means that the ocean is not blue. It is a clear color. This is because it can become many colors, and the scientific studies is that the water color is actually clear because when the water changes color, it is the same color with the sky.



The framework my opponent presented is partially acceptable. We should base our arguments on scientific argument, especially considering the topic at hand. However, plagiarizing is not an acceptable practice on DDO (or anywhere else.) Quoting an article is fine, but take care not to pass off someone else's words as your own. (You did do this when after the quote when you said "In other words..." Please mark off clearly when you are quoting an outside source.

As per the opponent's R1 structure, this Round is for presenting arguments and next round is for rebuttals. Therefore, I will not be addressing the opponent's arguments until next round.

Water is Blue

I will be demonstrating that water is intrinsically blue. In other words, I'll be proving that pure water has the quality of being blue, by the very nature of what water is.

This fact is actually referred to in the opponent's first source by the Scientific American. Here it says, "The ocean looks blue because red, orange and yellow (long wavelength light) are absorbed more strongly by water than is blue..." Here the article clearly states that water itself absorbs non-blue light more strongly than blue light, thus giving water its blue appearance (in large quantities.)

Of course, selective absorption of varying wavelengths of light is exactly what makes something have a color. If you paint a canvas entirely blue, it appears blue because the paint is not absorbing blue light, thus reflecting it. The same goes for water.

The Unique Blue of Water

Water is actually very unique in its 'blueness' as it is the only known natural substance whose color is due to changes in vibrational states, rather than interactions with electrons. [1] This is particularly interesting, as it means the color of water is entirely due to the chemical structure of water, rather than the state of the electrons present.

(Why water is unique in this way isn't particularly relevant to the debate, but it's interesting enough that it's worth being mentioned.)

The Appearance of Water

The last point that should be made concerns what color water appears to be, versus what color it actually is. Water is fairly translucent, in that one can see through it. This does not preclude the possibility of water having color as many known substances exist which obviously have a color but can also be seen through. (Rose colored glasses are an excellent example.)

If you were to fill a glass with water, it would not seem to have a color. This is because water is only very slightly blue. The blueness becomes more obvious when you look at a larger sample of water, such as the ocean or your local aquarium. A similar substance in this tune is glass. While glass also appears clear in small quantities, if you look at a larger sample (like a block of glass) it becomes apparent that glass is actually green (due to iron impurities.) In the case of water, looks really can be deceiving.


There really isn't much more to my argument than what's been presented. I used my opponent's evidence and my own to demonstrate that water is intrinsically blue, thus effectively negating the resolution. I look forward to my opponent's rebuttal and I look forward to offering my own.

(1) -
Debate Round No. 2


I thank Con for making his/ or hers arguments.


Opponent accepts most of the framework, however not plagiarizing. This is just for to reassure there is evidence.


1. My first rebuttal is about the argument of Water is Blue. Yes, if it reflects, it becomes
he color if the light. That means that water is not always blue. If we have a red light, then the water will be red. Swamp water is green because of slime and the trees. The opponent's argument does show that water is actually blue.

2. The chemical structure of water is 2 hydrogen and one oxygen. There is no reason why that refers to the "blueness" of water. Hydrogen is not blue, nor oxygen.

3. Water is blue in the ocean because it reflects the blue sky. It is not about little blueness making it blue. It is about water is clear and the clearness is reflecting by the blueness. It is not about lots of little blue making big blue.

I thank my opponent for his arguments.



I'll be covering my opponent's rebuttals in the order presented, labelling as I go along.

Water Changing Colors Based Upon Colored Light

The opponent argues that water can appear to have different colors based upon light passing through the water and various materials that may be present in water. I'll cover each.

First, the light argument. It is true that if you shine a red light through water, the water appears red. This is largely due to the partial transparency of water, but it does nothing to prove that water isn't intrinsically blue.

Consider that you can have two colored pieces of cellophane tape, one blue and one yellow. By placing the yellow piece on top of the blue piece, the result will appear to be a green cellophane piece of tape.

This, however, does not change the colors of each individual piece of tape. The top sheet is still yellow and the bottom is still blue. The same goes for passing light through water. While the water will appear to be the color of that light (very slightly mixed with blue), the water itself is still blue. This is obvious when you remove the colored light and are left with (very slightly) blue water.

The second point deals with particulates (like slime and mold) that may be present in the water. While this will appear to change the color of the water, one must realize that they are no longer looking at just water, but rather a mixture of two different substances. If you take some colored chalk, crush it into dust, then mix that with water -- the resulting mixture will appear the color of the chalk. What you're actually seeing, however, is the color of the chalk itself and the color of the water, blended together by your brain to form a new color.

The brain is incapable of seeing very small color differentiations. The proof is actually directly in front of you. Take a magnifying glass or droplet of water and apply it to your computer screen. You'll see that the variety of colors you see are actually just red, green and blue so close together it appears to be a new color. Same goes for water with other materials in it. The water itself, the molecule, is still intrinsically blue.

The Chemical Structure of Water

The opponent states that hydrogen is not blue, that oxygen is not blue, therefore water should not be blue. I earlier presented evidence that very clearly demonstrated the molecule of water appears blue because of the vibrations inherent in its structure. Prefer my evidence to the opponent's assertion.

Water is Blue Because of Reflections

Again, this is just an assertion. I have provided evidence proving that water itself is reflects back blue, while absorbing other colors in the spectrum. (Which makes it blue.) Yes, the sky is blue, which often makes water appear more blue than it actually is. However, if you had a large body of water underneath pure white light, the body of water would still appear blue.

Note that the ocean still appears deep blue during a sunset, a time in which the sky is a red-orange color.


The opponent used this round to make assertions without providing evidence to back them up. Last round, I presented a very clear, scientific source that demonstrates the "blueness" of water. Unless the opponent presents new evidence to the contrary, this evidence stands superior to all assertions made by the opponent in this debate.

Thanks for reading.

Debate Round No. 3


fire_wings forfeited this round.


Well, it looks like the "forfeit" glitch was fixed, pushing me 8 debates that have been over a while.

I believe my arguments still stand from last round. Vote for Con.
Debate Round No. 4
25 comments have been posted on this debate. Showing 1 through 10 records.
Posted by fire_wings 11 months ago
Cobalt, do you want to tie this debate, and start a new one later? I have to go somewhere for the holiday, 2 days.
Posted by famousdebater 11 months ago
@jonbonbon - It's actually a truism on Con's behalf. I would have loved to have accepted because Con is actually debating the truism not pro.
Posted by Jonbonbon 11 months ago
What's the point of this debate? It's a truism.
Posted by fire_wings 11 months ago
Stop commenting. I am out of my brains.
Posted by Cobalt 11 months ago
specifically, remove the words "which is dark", because that's not included in the wiki definition.
Posted by Cobalt 11 months ago
That's a bad place to get sources, but that's ok. Now change your summary of "blue" under "definitions" to match the wikipedia definition.
Posted by fire_wings 11 months ago
Dictionary is the Wikipedia
Posted by Cobalt 11 months ago
I won't debate you on the issue if you don't find a source for the word "blue". Your arbitrary definition doesn't match and dictionary's definition.
Posted by fire_wings 11 months ago
I changed it. Blue in the source was sad.
Posted by Cobalt 11 months ago
The definition of "blue" you provided does not match the definition of "blue" included in your source.
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