5 ms·

How To Imagine the Tenth Dimension

19 points by kwamenum86 16y ago

cianestro 16y ago
I'm glad my 4th-dimensional-former-undulating-self-blob observed this point on the 3rd dimensional plane. Obligatory link: http://news.ycombinator.com/item?id=1385543 http://news.ycombinator.com/item?id=1385543
herdrick 16y ago
http://news.ycombinator.com/item?id=1385736 http://news.ycombinator.com/item?id=1385736
- herdrick 16y ago
  And: http://news.ycombinator.com/item?id=1385745 http://news.ycombinator.com/item?id=1385745
  - cianestro 16y ago
    I have to disagree. Just because "results where in 5-space and up you can see and exist in all time simultaneously" appears to be "wacky" doesn't mean it's not possible. It's simply not part of your definition or interpretation of your current existence, which makes the 4th dimension seem out of place.
    - henrikschroder 16y ago
      Again, there's a huge difference between 4D space and 3D spacetime. Both are 4-dimensional mathematical spaces, but the visualization is completely different. "Time is the fourth dimension" is the single most damaging sentence for your understanding of time and space. To have an n-dimensional spacetime where time is not the nth dimension makes no sense.
      - bad_user 16y ago
        > "Time is the fourth dimension" is the single most damaging sentence for your understanding of time and space. The video didn't expand on the person living in a 2D space example ... if such of thing would be possible, he would be able to explain the presence of a third dimension using time (going so far as to consider time as being the third dimension).
        henrikschroder 16y ago
        he would be able to explain the presence of a third dimension using time NO! Absolutely not! 2D spacetime does not look like 3D space at all! In 3D space, I can take a 2D angle bracket, flip it in the third dimension, and get its mirror image. This will seem like magic to 2D creatures. In 2D spacetime, I can do no such thing. No matter how long I wait (i.e. move in the third time dimension), the angle bracket won't transform into its mirror image. In 4D space, I can take a 3D right-hand glove, flip it in the fourth dimension, and get a left-hand glove. This will seem like magic to 3D creatures. In 3D spacetime I can do no such thing. No matter how long I wait, a right-hand glove will never transform into a left-hand glove. Do you understand? Do you see how adding time to n-dimensional space does absolutely nothing to explain n+1 space?
        rbanffy 16y ago
        That's because dimensions are not ordered. There is no first dimension, or second, or third. For a flatlander, time is what he perceives as a third dimension. Depth may be a fourth dimension. If you wanted to do the same trick to you, you would have to flip yourself in a non-time higher dimensional space. I think any dimensional space would do. But it's early in the morning and I haven't had breakfast. Talk to you when my brain joins me. To perceive time as a dimension is useful because it helps you realize you actually perceive four dimensions the same way a flatlander perceives three.
        henrikschroder 16y ago
        To perceive time as a dimension is useful If you want to do space-time calculations, yes. because it helps you realize you actually perceive four dimensions the same way a flatlander perceives three Absolutely not. We perceive time as time and space as space. The concept of spacetime does not help us understand or visualize higher dimensional spaces at all. It only confuses the issue, which is exactly the original complaint against the video this whole discussion is about. Edit: One more example: Can you visualize the difference between a 3D cube moving in time, and a 4D cube moving in the 4th dimension? If you project the 4D cube down to 3D, it will look like a double cube that twists itself inside and out, but the 3D cube moving in time will just look like a 3D cube. Spacetime does not help you understanding 4D space.
Synthetase 16y ago
I hate to be a spoil sort but the guy that made this doesn't know what he's talking about. He' a musician, not a physicist or mathematician. His proposition fails past the fourth dimension.
roundsquare 16y ago
I really hate this video. It makes things more complicated than needed. You can't "visualize" the fourth dimension (or I haven't met anyone who could... and the kind of math/physics where this comes up was a common topic for me for a while). However, you can understand it pretty easily. Its really just another coordinate. You can do algebra with it. If I say someone is at (3, 2, 5, 6) and moves (1, 2, 3, 4) they are now at (4, 4, 8, 10)... Want a 5th dimension? Add another comma/number. People who "visualize" the higher dimensions actually visualize 2 or 3 dimensions and know how to generalize (from practice/experience/theorems).
- bad_user 16y ago
  I think the question that most often comes up is how many dimensions are we living in? And, are all of them equal? Sure, on paper you can have as many dimensions as you like, just add coordinates, but that won't help us come up with the grand unified theory, or find other new laws of our universe, which might have pretty useful practical applications. Unfortunately we are limited in seeing beyond our primary senses.
  - wendroid 16y ago
    Quite simple, you'll never know. It's like someone in 2d trying to detect 3d, you are presented with a projection and have to extrapolate, but the number of unknowns is, well, unknown.
  - roundsquare 16y ago
    Its a fair point... sadly I don't know the answer in any great details. What little I know says there are 26 dimensions and they are not all equal. 3 of space, 1 of time, and 22... others... Actually, I wonder, when people usually ask this question, are they just using the word dimension as a buzz word or do they know what it means?
- jules 16y ago
  You can visualize the 4th dimension. Just imagine 3d space moving through time. 5 is where is starts to be problematic. BTW the video is ok until 4:30. Then it quickly degrades into nonsense, not just more complicated than needed.
ErrantX 16y ago
This is what a physicist friend sent to me a while ago: "there is really little point in trying to graphically represent anything beyond spacetime. Possibly 3D space with a time vector is useful (i.e. an object representing 3D space moving along a vector) because it is still helpful to explain the concepts. Beyond that just stick with the numbers or you risk confusing yourself on what is being talked about"

19 points by kwamenum86 16y ago

I'm glad my 4th-dimensional-former-undulating-self-blob observed this point on the 3rd dimensional plane. Obligatory link: http://news.ycombinator.com/item?id=1385543 http://news.ycombinator.com/item?id=1385543

herdrick 16y ago

http://news.ycombinator.com/item?id=1385736 http://news.ycombinator.com/item?id=1385736

herdrick 16y ago
And: http://news.ycombinator.com/item?id=1385745 http://news.ycombinator.com/item?id=1385745
- cianestro 16y ago
  I have to disagree. Just because "results where in 5-space and up you can see and exist in all time simultaneously" appears to be "wacky" doesn't mean it's not possible. It's simply not part of your definition or interpretation of your current existence, which makes the 4th dimension seem out of place.
  - henrikschroder 16y ago
    Again, there's a huge difference between 4D space and 3D spacetime. Both are 4-dimensional mathematical spaces, but the visualization is completely different. "Time is the fourth dimension" is the single most damaging sentence for your understanding of time and space. To have an n-dimensional spacetime where time is not the nth dimension makes no sense.
    - bad_user 16y ago
      > "Time is the fourth dimension" is the single most damaging sentence for your understanding of time and space. The video didn't expand on the person living in a 2D space example ... if such of thing would be possible, he would be able to explain the presence of a third dimension using time (going so far as to consider time as being the third dimension).
      - henrikschroder 16y ago
        he would be able to explain the presence of a third dimension using time NO! Absolutely not! 2D spacetime does not look like 3D space at all! In 3D space, I can take a 2D angle bracket, flip it in the third dimension, and get its mirror image. This will seem like magic to 2D creatures. In 2D spacetime, I can do no such thing. No matter how long I wait (i.e. move in the third time dimension), the angle bracket won't transform into its mirror image. In 4D space, I can take a 3D right-hand glove, flip it in the fourth dimension, and get a left-hand glove. This will seem like magic to 3D creatures. In 3D spacetime I can do no such thing. No matter how long I wait, a right-hand glove will never transform into a left-hand glove. Do you understand? Do you see how adding time to n-dimensional space does absolutely nothing to explain n+1 space?
        rbanffy 16y ago
        That's because dimensions are not ordered. There is no first dimension, or second, or third. For a flatlander, time is what he perceives as a third dimension. Depth may be a fourth dimension. If you wanted to do the same trick to you, you would have to flip yourself in a non-time higher dimensional space. I think any dimensional space would do. But it's early in the morning and I haven't had breakfast. Talk to you when my brain joins me. To perceive time as a dimension is useful because it helps you realize you actually perceive four dimensions the same way a flatlander perceives three.
        henrikschroder 16y ago
        To perceive time as a dimension is useful If you want to do space-time calculations, yes. because it helps you realize you actually perceive four dimensions the same way a flatlander perceives three Absolutely not. We perceive time as time and space as space. The concept of spacetime does not help us understand or visualize higher dimensional spaces at all. It only confuses the issue, which is exactly the original complaint against the video this whole discussion is about. Edit: One more example: Can you visualize the difference between a 3D cube moving in time, and a 4D cube moving in the 4th dimension? If you project the 4D cube down to 3D, it will look like a double cube that twists itself inside and out, but the 3D cube moving in time will just look like a 3D cube. Spacetime does not help you understanding 4D space.

Synthetase 16y ago

I hate to be a spoil sort but the guy that made this doesn't know what he's talking about. He' a musician, not a physicist or mathematician. His proposition fails past the fourth dimension.

roundsquare 16y ago

I really hate this video. It makes things more complicated than needed. You can't "visualize" the fourth dimension (or I haven't met anyone who could... and the kind of math/physics where this comes up was a common topic for me for a while). However, you can understand it pretty easily. Its really just another coordinate. You can do algebra with it. If I say someone is at (3, 2, 5, 6) and moves (1, 2, 3, 4) they are now at (4, 4, 8, 10)... Want a 5th dimension? Add another comma/number. People who "visualize" the higher dimensions actually visualize 2 or 3 dimensions and know how to generalize (from practice/experience/theorems).

bad_user 16y ago
I think the question that most often comes up is how many dimensions are we living in? And, are all of them equal? Sure, on paper you can have as many dimensions as you like, just add coordinates, but that won't help us come up with the grand unified theory, or find other new laws of our universe, which might have pretty useful practical applications. Unfortunately we are limited in seeing beyond our primary senses.
- wendroid 16y ago
  Quite simple, you'll never know. It's like someone in 2d trying to detect 3d, you are presented with a projection and have to extrapolate, but the number of unknowns is, well, unknown.
- roundsquare 16y ago
  Its a fair point... sadly I don't know the answer in any great details. What little I know says there are 26 dimensions and they are not all equal. 3 of space, 1 of time, and 22... others... Actually, I wonder, when people usually ask this question, are they just using the word dimension as a buzz word or do they know what it means?
jules 16y ago
You can visualize the 4th dimension. Just imagine 3d space moving through time. 5 is where is starts to be problematic. BTW the video is ok until 4:30. Then it quickly degrades into nonsense, not just more complicated than needed.

ErrantX 16y ago

This is what a physicist friend sent to me a while ago: "there is really little point in trying to graphically represent anything beyond spacetime. Possibly 3D space with a time vector is useful (i.e. an object representing 3D space moving along a vector) because it is still helpful to explain the concepts. Beyond that just stick with the numbers or you risk confusing yourself on what is being talked about"