<p>The best known examples of impossible objects are one of the following (but there are a multitude of others around). </p>

<p>Of course they exist as you see right in front of you on your screen. Yet, that is in 2D space. If you imagine these objects to be 'real' matter, so imaginary physical objects, and imagine tracing the cube's ribs (Fig. 1) with your finger, or the ribs of the triangle (Fig. 2), or the tripod (Fig. 3) you are imagining the impossible. Such an object cannot exist in 3D space. Likewise, if you imagine tracing the water in the waterfall (fig. 4) falling and flowing back up, against the laws of gravity, you definitely imagine an impossible thing, as such a scenario can only exist in 2D space - our mind tricks us into assembling an impossible 3D perception out of a 2D image.   </p>

<p>Escher has made many of these impossible objects that exist only in 2D space.</p>

<p><sub><strong>Reference</strong><br>
<a href="https://www.bol.com/nl/p/escher-op-reis/9200000091494103/?Referrer=ADVNLGOO002008P-G-69733010818-S-664287831040-9200000091494103&amp;gclid=CjwKCAjw-ITqBRB7EiwAZ1c5UzFaDuYF8kWMbtjQpPYIEkLLYsmw5ep0uIkYH-uWLgxCTcHQF9Wr_xoCQWUQAvD_BwE" rel="nofollow noreferrer">Escher op reis. Frederico Giudiceandrea</a></sub> </p>

<p><a href="https://i.sstatic.net/yBOlm.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/yBOlm.png" alt="impossibleCube"></a><br>
<sup>Fig. 1. Impossible cube. source: <a href="https://mathstat.slu.edu/escher/index.php/Depth_and_Perspective" rel="nofollow noreferrer">SLU Math</a></sup></p>

<p><a href="https://i.sstatic.net/ENcQN.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/ENcQN.png" alt="ImpossibleTriangle"></a><br>
<sup>Fig. 2. Impossible triangle. source: <a href="http://brainden.com/impossible-objects.htm" rel="nofollow noreferrer">Brain Teaser</a></sup></p>

<p><a href="https://i.sstatic.net/GfGNx.gif" rel="nofollow noreferrer"><img src="https://i.sstatic.net/GfGNx.gif" alt="impossible"></a><br>
<sup>Fig. 3. Impossible tripod. source: <a href="http://piscesdna.blogspot.com/2010/07/" rel="nofollow noreferrer">Piscesdna</a></sup> </p>

<p><a href="https://i.sstatic.net/Ee1A3.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/Ee1A3.jpg" alt="enter image description here"></a><br>
<sup>Fig. 4. Escher's Waterfall ('Waterval'). source: <a href="https://psych.hanover.edu/Krantz/art/imposs.html" rel="nofollow noreferrer">Hanover College</a></sup></p>

CC BY-SA 4.0
2019-07-31T13:13:11.243Z
2019-07-31T14:23:31.030Z
2019-07-31T14:23:31.030Z
AliceD
<p>This is probably the most adequate stackexchange for this question.</p>

<p>Is it possible to imagine something that does not exist, explicitly or implicitly, in our universe?</p>

<p>Exclude things such as a Unicorn for example, that's just a horse and the corn is from other animals who have such an "organ". Other stuff might be just an application of the laws of nature. Our images of extraterrestrials usually involve hands, eyes, holes as nose etc.. which we do know of.</p>

CC BY-SA 4.0
2019-07-30T22:56:22.103Z
Might actually be better for Philosophy, although they kicked the most recent form of this question over here where it wasn't received too well if I recall. How do you propose testing this? Clearly we can imagine things that don't exist, you've given some examples, but you've discarded them because you say they are made up of other real things. How would someone describe it to you if it does not exist and does not have a relationship to other things? Does God count? Time travel doesn't exist but is a common trope in literature - does that count?
Bryan Krause
CC BY-SA 4.0
2019-07-30T23:51:23.190Z
@BryanKrause "How would someone describe it to you if it does not exist and does not have a relationship to other things?" if it is a physical thing, it might drawn, however, if it's the case, it might be just a construction of other real things. so I guess in general he can't. "Does God count?" I think this might be an argument for god, if we can't imagine things that do not exist, then god is not a human construct. "Time travel doesn't exist but is a common trope in literature - does that count?" one can notice that as time passes we "travel" to "the future".
GDGDJKJ
CC BY-SA 4.0
2019-07-31T00:08:41.410Z
Yes I suspect no evidence will convince you one way or another, so it is not a good science question (but maybe a good philosophy one). It seems you have already made up your mind and if I describe something that doesn't exist, you will either say A) It does exist (e.g., god), or B) It's just made up of things that do exist, so not an example.
Bryan Krause
CC BY-SA 4.0
2019-07-31T00:27:47.407Z
"Yes I suspect no evidence will convince you one way or another"? "A) It does exist (e.g., god)" I never said that, I said that if this is true then we can infer that.
GDGDJKJ
<cognitive-psychology><philosophy-of-mind><imagery>
Imagining unreal stuff
GDGDJKJ
# Imagining unreal stuff

(Asked by: username_0 on 2019-07-30)

This is probably the most adequate stackexchange for this question.

Is it possible to imagine something that does not exist, explicitly or implicitly, in our universe?

Exclude things such as a Unicorn for example, that's just a horse and the corn is from other animals who have such an "organ". Other stuff might be just an application of the laws of nature. Our images of extraterrestrials usually involve hands, eyes, holes as nose etc.. which we do know of.

**Tags:** cognitive-psychology, philosophy-of-mind, imagery

> **Comments:**
> **username_1**: Might actually be better for Philosophy, although they kicked the most recent form of this question over here where it wasn't received too well if I recall. How do you propose testing this? Clearly we can imagine things that don't exist, you've given some examples, but you've discarded them because you say they are made up of other real things. How would someone describe it to you if it does not exist and does not have a relationship to other things? Does God count? Time travel doesn't exist but is a common trope in literature - does that count?  
> **username_0**: @BryanKrause "How would someone describe it to you if it does not exist and does not have a relationship to other things?" if it is a physical thing, it might drawn, however, if it's the case, it might be just a construction of other real things. so I guess in general he can't. "Does God count?" I think this might be an argument for god, if we can't imagine things that do not exist, then god is not a human construct. "Time travel doesn't exist but is a common trope in literature - does that count?" one can notice that as time passes we "travel" to "the future".  
> **username_1**: Yes I suspect no evidence will convince you one way or another, so it is not a good science question (but maybe a good philosophy one). It seems you have already made up your mind and if I describe something that doesn't exist, you will either say A) It does exist (e.g., god), or B) It's just made up of things that do exist, so not an example.  
> **username_0**: "Yes I suspect no evidence will convince you one way or another"? "A) It does exist (e.g., god)" I never said that, I said that if this is true then we can infer that.  

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## 1 answers

### Answer by username_2 on 2019-07-31. Score: 1

The best known examples of impossible objects are one of the following (but there are a multitude of others around).

Of course they exist as you see right in front of you on your screen. Yet, that is in 2D space. If you imagine these objects to be 'real' matter, so imaginary physical objects, and imagine tracing the cube's ribs (Fig. 1) with your finger, or the ribs of the triangle (Fig. 2), or the tripod (Fig. 3) you are imagining the impossible. Such an object cannot exist in 3D space. Likewise, if you imagine tracing the water in the waterfall (fig. 4) falling and flowing back up, against the laws of gravity, you definitely imagine an impossible thing, as such a scenario can only exist in 2D space - our mind tricks us into assembling an impossible 3D perception out of a 2D image.

Escher has made many of these impossible objects that exist only in 2D space.

**Reference**  
[Escher op reis. Frederico Giudiceandrea](https://www.bol.com/nl/p/escher-op-reis/9200000091494103/?Referrer=ADVNLGOO002008P-G-69733010818-S-664287831040-9200000091494103&gclid=CjwKCAjw-ITqBRB7EiwAZ1c5UzFaDuYF8kWMbtjQpPYIEkLLYsmw5ep0uIkYH-uWLgxCTcHQF9Wr_xoCQWUQAvD_BwE)

[![impossibleCube](https://i.sstatic.net/yBOlm.png)](https://i.sstatic.net/yBOlm.png)  
Fig. 1. Impossible cube. source: [SLU Math](https://mathstat.slu.edu/escher/index.php/Depth_and_Perspective)

[![ImpossibleTriangle](https://i.sstatic.net/ENcQN.png)](https://i.sstatic.net/ENcQN.png)  
Fig. 2. Impossible triangle. source: [Brain Teaser](http://brainden.com/impossible-objects.htm)

[![impossible](https://i.sstatic.net/GfGNx.gif)](https://i.sstatic.net/GfGNx.gif)  
Fig. 3. Impossible tripod. source: [Piscesdna](http://piscesdna.blogspot.com/2010/07/)

[![enter image description here](https://i.sstatic.net/Ee1A3.jpg)](https://i.sstatic.net/Ee1A3.jpg)  
Fig. 4. Escher's Waterfall ('Waterval'). source: [Hanover College](https://psych.hanover.edu/Krantz/art/imposs.html)


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