What shapes do these quotients represent? Do they have a name?












3












$begingroup$


I am unable to visualize complex shapes in space. I can draw simpler shapes and explain which points correspond to which but can't for the life of me determine the name of the shape. I would like somebody to help me identify those. I will present my thought process through a picture since it is very difficult to explain with words.



I am given the quotients $mathbb{R}/mathbb{Z} times[0,1]/sim$ where $sim$ denotes $(t,0) sim (-t,1)$ and $mathbb{R}/mathbb{Z} times[0,1]/sim'$ where $sim'$ denotes $(t,0) sim (t,1)$.



I think the first quotient represents a cylinder whose opposite edges at extremities are "identified", i.e. it looks kind of a Möbius strip but I don't think it is the Möbius strip because of instead of having sides as extremities there are circles. I have made a drawing to see things better but I still can't identify the correct shape. Maybe some kind of 8-looking strip that's not Möbius?



The second one seems easier and I guess it's just the torus... Am I right?



For the first one:



enter image description here



if I try to "identify" the circles in my head I just get some kind of strip that intersects itself like an "8" strip. Does this shape have a name? I have low spatial IQ










share|cite|improve this question











$endgroup$








  • 5




    $begingroup$
    This is better known as the Klein bottle. It has no boundary.
    $endgroup$
    – user98602
    Jan 30 at 18:01










  • $begingroup$
    @MikeMiller I did look at the Klein bottle before posting, but still couldn't see how circles were oppositely-identified. Now that I know the answer, I see it. (I didn't pay enough attention to the fact that the "bend" essentially makes this cross-identification I couldn't put my finger on...) Well thank you, I guess this qualifies as an answer, however short...
    $endgroup$
    – Evariste
    Jan 30 at 18:06








  • 1




    $begingroup$
    I would have drawn pictures if I had the capability :) Maybe you will be able to do so and post an answer. I would upvote.
    $endgroup$
    – user98602
    Jan 30 at 18:11










  • $begingroup$
    @MikeMiller A Klein bottle on paint will look like no Klein bottle, might as well quote or link en.wikipedia.org/wiki/Klein_bottle, still I can't answer my own question if somebody else just gave me the answer
    $endgroup$
    – Evariste
    Jan 30 at 18:17
















3












$begingroup$


I am unable to visualize complex shapes in space. I can draw simpler shapes and explain which points correspond to which but can't for the life of me determine the name of the shape. I would like somebody to help me identify those. I will present my thought process through a picture since it is very difficult to explain with words.



I am given the quotients $mathbb{R}/mathbb{Z} times[0,1]/sim$ where $sim$ denotes $(t,0) sim (-t,1)$ and $mathbb{R}/mathbb{Z} times[0,1]/sim'$ where $sim'$ denotes $(t,0) sim (t,1)$.



I think the first quotient represents a cylinder whose opposite edges at extremities are "identified", i.e. it looks kind of a Möbius strip but I don't think it is the Möbius strip because of instead of having sides as extremities there are circles. I have made a drawing to see things better but I still can't identify the correct shape. Maybe some kind of 8-looking strip that's not Möbius?



The second one seems easier and I guess it's just the torus... Am I right?



For the first one:



enter image description here



if I try to "identify" the circles in my head I just get some kind of strip that intersects itself like an "8" strip. Does this shape have a name? I have low spatial IQ










share|cite|improve this question











$endgroup$








  • 5




    $begingroup$
    This is better known as the Klein bottle. It has no boundary.
    $endgroup$
    – user98602
    Jan 30 at 18:01










  • $begingroup$
    @MikeMiller I did look at the Klein bottle before posting, but still couldn't see how circles were oppositely-identified. Now that I know the answer, I see it. (I didn't pay enough attention to the fact that the "bend" essentially makes this cross-identification I couldn't put my finger on...) Well thank you, I guess this qualifies as an answer, however short...
    $endgroup$
    – Evariste
    Jan 30 at 18:06








  • 1




    $begingroup$
    I would have drawn pictures if I had the capability :) Maybe you will be able to do so and post an answer. I would upvote.
    $endgroup$
    – user98602
    Jan 30 at 18:11










  • $begingroup$
    @MikeMiller A Klein bottle on paint will look like no Klein bottle, might as well quote or link en.wikipedia.org/wiki/Klein_bottle, still I can't answer my own question if somebody else just gave me the answer
    $endgroup$
    – Evariste
    Jan 30 at 18:17














3












3








3





$begingroup$


I am unable to visualize complex shapes in space. I can draw simpler shapes and explain which points correspond to which but can't for the life of me determine the name of the shape. I would like somebody to help me identify those. I will present my thought process through a picture since it is very difficult to explain with words.



I am given the quotients $mathbb{R}/mathbb{Z} times[0,1]/sim$ where $sim$ denotes $(t,0) sim (-t,1)$ and $mathbb{R}/mathbb{Z} times[0,1]/sim'$ where $sim'$ denotes $(t,0) sim (t,1)$.



I think the first quotient represents a cylinder whose opposite edges at extremities are "identified", i.e. it looks kind of a Möbius strip but I don't think it is the Möbius strip because of instead of having sides as extremities there are circles. I have made a drawing to see things better but I still can't identify the correct shape. Maybe some kind of 8-looking strip that's not Möbius?



The second one seems easier and I guess it's just the torus... Am I right?



For the first one:



enter image description here



if I try to "identify" the circles in my head I just get some kind of strip that intersects itself like an "8" strip. Does this shape have a name? I have low spatial IQ










share|cite|improve this question











$endgroup$




I am unable to visualize complex shapes in space. I can draw simpler shapes and explain which points correspond to which but can't for the life of me determine the name of the shape. I would like somebody to help me identify those. I will present my thought process through a picture since it is very difficult to explain with words.



I am given the quotients $mathbb{R}/mathbb{Z} times[0,1]/sim$ where $sim$ denotes $(t,0) sim (-t,1)$ and $mathbb{R}/mathbb{Z} times[0,1]/sim'$ where $sim'$ denotes $(t,0) sim (t,1)$.



I think the first quotient represents a cylinder whose opposite edges at extremities are "identified", i.e. it looks kind of a Möbius strip but I don't think it is the Möbius strip because of instead of having sides as extremities there are circles. I have made a drawing to see things better but I still can't identify the correct shape. Maybe some kind of 8-looking strip that's not Möbius?



The second one seems easier and I guess it's just the torus... Am I right?



For the first one:



enter image description here



if I try to "identify" the circles in my head I just get some kind of strip that intersects itself like an "8" strip. Does this shape have a name? I have low spatial IQ







geometry geometric-topology






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Jan 30 at 17:57







Evariste

















asked Jan 30 at 17:50









EvaristeEvariste

1,1862618




1,1862618








  • 5




    $begingroup$
    This is better known as the Klein bottle. It has no boundary.
    $endgroup$
    – user98602
    Jan 30 at 18:01










  • $begingroup$
    @MikeMiller I did look at the Klein bottle before posting, but still couldn't see how circles were oppositely-identified. Now that I know the answer, I see it. (I didn't pay enough attention to the fact that the "bend" essentially makes this cross-identification I couldn't put my finger on...) Well thank you, I guess this qualifies as an answer, however short...
    $endgroup$
    – Evariste
    Jan 30 at 18:06








  • 1




    $begingroup$
    I would have drawn pictures if I had the capability :) Maybe you will be able to do so and post an answer. I would upvote.
    $endgroup$
    – user98602
    Jan 30 at 18:11










  • $begingroup$
    @MikeMiller A Klein bottle on paint will look like no Klein bottle, might as well quote or link en.wikipedia.org/wiki/Klein_bottle, still I can't answer my own question if somebody else just gave me the answer
    $endgroup$
    – Evariste
    Jan 30 at 18:17














  • 5




    $begingroup$
    This is better known as the Klein bottle. It has no boundary.
    $endgroup$
    – user98602
    Jan 30 at 18:01










  • $begingroup$
    @MikeMiller I did look at the Klein bottle before posting, but still couldn't see how circles were oppositely-identified. Now that I know the answer, I see it. (I didn't pay enough attention to the fact that the "bend" essentially makes this cross-identification I couldn't put my finger on...) Well thank you, I guess this qualifies as an answer, however short...
    $endgroup$
    – Evariste
    Jan 30 at 18:06








  • 1




    $begingroup$
    I would have drawn pictures if I had the capability :) Maybe you will be able to do so and post an answer. I would upvote.
    $endgroup$
    – user98602
    Jan 30 at 18:11










  • $begingroup$
    @MikeMiller A Klein bottle on paint will look like no Klein bottle, might as well quote or link en.wikipedia.org/wiki/Klein_bottle, still I can't answer my own question if somebody else just gave me the answer
    $endgroup$
    – Evariste
    Jan 30 at 18:17








5




5




$begingroup$
This is better known as the Klein bottle. It has no boundary.
$endgroup$
– user98602
Jan 30 at 18:01




$begingroup$
This is better known as the Klein bottle. It has no boundary.
$endgroup$
– user98602
Jan 30 at 18:01












$begingroup$
@MikeMiller I did look at the Klein bottle before posting, but still couldn't see how circles were oppositely-identified. Now that I know the answer, I see it. (I didn't pay enough attention to the fact that the "bend" essentially makes this cross-identification I couldn't put my finger on...) Well thank you, I guess this qualifies as an answer, however short...
$endgroup$
– Evariste
Jan 30 at 18:06






$begingroup$
@MikeMiller I did look at the Klein bottle before posting, but still couldn't see how circles were oppositely-identified. Now that I know the answer, I see it. (I didn't pay enough attention to the fact that the "bend" essentially makes this cross-identification I couldn't put my finger on...) Well thank you, I guess this qualifies as an answer, however short...
$endgroup$
– Evariste
Jan 30 at 18:06






1




1




$begingroup$
I would have drawn pictures if I had the capability :) Maybe you will be able to do so and post an answer. I would upvote.
$endgroup$
– user98602
Jan 30 at 18:11




$begingroup$
I would have drawn pictures if I had the capability :) Maybe you will be able to do so and post an answer. I would upvote.
$endgroup$
– user98602
Jan 30 at 18:11












$begingroup$
@MikeMiller A Klein bottle on paint will look like no Klein bottle, might as well quote or link en.wikipedia.org/wiki/Klein_bottle, still I can't answer my own question if somebody else just gave me the answer
$endgroup$
– Evariste
Jan 30 at 18:17




$begingroup$
@MikeMiller A Klein bottle on paint will look like no Klein bottle, might as well quote or link en.wikipedia.org/wiki/Klein_bottle, still I can't answer my own question if somebody else just gave me the answer
$endgroup$
– Evariste
Jan 30 at 18:17










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