hi members ,
Can any body tell me some thing about 4th dimention?best wishes..subir
Can any body tell me some thing about 4th dimention?best wishes..subir
4th dimention
Well, I'm only 16 and not a science-freak, so I'm just gonna guess what I heard things about it:
We live in 3D, 3th dimension. But since we cannot 'imagine' what the 4th dimension is, its impossible to understand. Its like you would live in a comic book, and you cannot understand that there is a world like this in 3D. I think its like you cannot draw 3D in a comic book.
Wikipedia has this to offer:
We live in 3D, 3th dimension. But since we cannot 'imagine' what the 4th dimension is, its impossible to understand. Its like you would live in a comic book, and you cannot understand that there is a world like this in 3D. I think its like you cannot draw 3D in a comic book.
Wikipedia has this to offer:
| Quote: |
| Such a space differs from our more familiar three-dimensional space in that it has an additional dimension, a new direction in which movement is possible. This fourth spatial dimension is a concept distinct from the time dimension in spacetime. |
Ahhh, the 4th dimension, true can be hard to understand. Anyone, can correct me if I'm wrong here, I think that the 4th dimension is time.
The 1st dimension is a fixed point in space.
The 2nd is a line, and
the 3rd is a plane.
the 4th is time, and
their are others but I don't remember them. I think gravity is one not sure on that though.
The 1st dimension is a fixed point in space.
The 2nd is a line, and
the 3rd is a plane.
the 4th is time, and
their are others but I don't remember them. I think gravity is one not sure on that though.
One simple way to imagine dimensions are the co-ordinates you need to specify in order to locate something.
If I was to specify my location in space then I have to give 3 numbers (relative to some other fixed point). Those are the distances from that fixed point (in terms of left/right, up/down and forward/backward). Now, those 3 co-ordinates identify a fixed point in space but they do NOT identify the time, so I might have moved. To identify me at a fixed time AND location you need 4 co-ordinates (called the spacetime coordinates). 3 to specify the position in space and 1 to specify the position in time. Hence we can regard time as a 4th dimension.
Now, Einstein took this a whole lot further by combining space and time into a single 'fabric' called spacetime. According to Einstein's theory (Relativity) we move in both time and space. When we are (relatively) stationary then we are moving 'full speed' through time (at the speed of light). If we are moving very fast through space then we are moving (relatively) much slower through time. The total of our movement in space and time always adds up to c (the speed of light).
If I was to specify my location in space then I have to give 3 numbers (relative to some other fixed point). Those are the distances from that fixed point (in terms of left/right, up/down and forward/backward). Now, those 3 co-ordinates identify a fixed point in space but they do NOT identify the time, so I might have moved. To identify me at a fixed time AND location you need 4 co-ordinates (called the spacetime coordinates). 3 to specify the position in space and 1 to specify the position in time. Hence we can regard time as a 4th dimension.
Now, Einstein took this a whole lot further by combining space and time into a single 'fabric' called spacetime. According to Einstein's theory (Relativity) we move in both time and space. When we are (relatively) stationary then we are moving 'full speed' through time (at the speed of light). If we are moving very fast through space then we are moving (relatively) much slower through time. The total of our movement in space and time always adds up to c (the speed of light).
I think this might be a good link to post here. Covers a lot more, but should also help you understand why.
The interesting thing about this 4th dimension is that you can perform mathematics in it.
In 3D, points have coordinates like (1, 1, 1) and (0, 0, 0). (0, 0, 0) would be one point, and (1, 1, 1) would be e.g. one meter to the north, one meter to the east and one meter up. These two points are 1.73 meters away from eachother. In 4D, you can say that the distance between (0, 0, 0, 0) and (1, 1, 1, 1) is 2 meters.
Also, you can have mathematical shapes in 4D, e.g. just like the 2D circle and the 3D sphere, you have a 4D shape called a 3-sphere that has the same properties as a normal sphere.
It's interesting to think the world could exist in 4D as well.
In 3D, points have coordinates like (1, 1, 1) and (0, 0, 0). (0, 0, 0) would be one point, and (1, 1, 1) would be e.g. one meter to the north, one meter to the east and one meter up. These two points are 1.73 meters away from eachother. In 4D, you can say that the distance between (0, 0, 0, 0) and (1, 1, 1, 1) is 2 meters.
Also, you can have mathematical shapes in 4D, e.g. just like the 2D circle and the 3D sphere, you have a 4D shape called a 3-sphere that has the same properties as a normal sphere.
It's interesting to think the world could exist in 4D as well.
| Stubru Freak wrote: |
| The interesting thing about this 4th dimension is that you can perform mathematics in it.
In 3D, points have coordinates like (1, 1, 1) and (0, 0, 0). (0, 0, 0) would be one point, and (1, 1, 1) would be e.g. one meter to the north, one meter to the east and one meter up. These two points are 1.73 meters away from eachother. In 4D, you can say that the distance between (0, 0, 0, 0) and (1, 1, 1, 1) is 2 meters. Also, you can have mathematical shapes in 4D, e.g. just like the 2D circle and the 3D sphere, you have a 4D shape called a 3-sphere that has the same properties as a normal sphere. It's interesting to think the world could exist in 4D as well. |
That's only the beginning of what makes a 4th spatial dimension cool. If a 4th spatial dimension exists, and is not "curled" in the string theory sense, we can do some wicked awesome things. For example, i could take a left shoe and turn it into a right shoe... by rotating it in the 4th dimension.
That's neat, but that's only gimmicky. Imagine this: a surgeon wants to do heart bypass surgery on a patient. So he lays the patient down on the table, and then rotates the patient in the 4th dimension. Now he can see inside the patient... in fact, the patient's insides are as plain as day to him... yet the patient hasn't been cut and is still alive. Maybe even awake! The surgeon does the bypass, and then rotates the patient back... all without making a single cut into the patient!
I do not believe in 4D. I think scientists are wasting time after it. Its really complex to imagine a 4 dimensional space. I don't understand why scientists are considering time as a dimension and why they believe that we can back in the past.
A common held belief is that time travel backwards is impossible. That time is like a funnel. As time advances the world tends to acheive a higher level of order. As time goes backwards it goes toward chaos. The thought is that you can't tavel into chaos or else you will disentigrate or something.
| jwellsy wrote: |
| A common held belief is that time travel backwards is impossible. That time is like a funnel. As time advances the world tends to acheive a higher level of order. As time goes backwards it goes toward chaos. The thought is that you can't tavel into chaos or else you will disentigrate or something. |
1- Time travel to the past is theoretically possible.
2- According to entropy, the universe is moving from order to chaos, not the other way around. The future should be more 'chaotic' than the past.
I agree that all things decay over time and that the universe is currently expanding. I've also read many articles that describe time as an hourglass and it's only the current time that is in focus.
Wikipedia talks to the backwards time travel debate.
http://en.wikipedia.org/wiki/Time_travel
Wikipedia talks to the backwards time travel debate.
http://en.wikipedia.org/wiki/Time_travel
| Quote: |
|
Some interpretations of time travel also suggest that an attempt to travel backwards in time might take one to a parallel universe whose history would begin to diverge from the traveler's original history after the moment the traveler arrived in the past.[1] Although time travel has been a common plot device in fiction since the 19th century, and one-way travel into the future is arguably possible given the phenomenon of time dilation based on velocity in the theory of special relativity (exemplified by the twin paradox) as well as gravitational time dilation in the theory of general relativity, it is currently unknown whether the laws of physics would allow backwards time travel. |
| jwellsy wrote: | ||
|
The laws of physics that we know of do allow the formation of wormholes, which could be used to travel to the past.
This can be done in two ways:
A- with a huge, spinning, cylindrical, hollow black hole. (really hard to make)
B- using 'exotic matter', which could exist, but has never been discovered even in the tiniest amounts.
Both of these ways would allow the formation of a wormhole, which might possibly connect to the past, without breaking the laws of physics as we know them... Though those laws could be very, very wrong.
I think it's just an extension of our first three dimensions. It shouldn't really exist. The 4th dimension starts back like a line again, only higher up than the first dimension.
1,2 and 3 dimension motion is easy understood by any one
4th dimension is Time. This term has a major role in theory of relativity
4th dimension is Time. This term has a major role in theory of relativity
| subirbasak wrote: |
| hi members ,
Can any body tell me some thing about 4th dimention?best wishes..subir |
are you talking about the 4th dimension time or the dimension that is right angle to all the 3 spatial dimensions?
take a line in one dimension. draw a line right angle to it and you find the 2nd dimension. draw right angle to both and you find 3rd dimension (like in a cube). draw right angles to all and you get 4th dimension. this is mathematically proven to exist, but since we are trapped in thrid dimension we cannot perceive this 4th dimension. in 4th dimension the universe exists as a hypersphere. and the space of 4 dimensions is called Hyperspace.
you shoud read Carl Sagan's Cosmos book, there's something about this that is very interesting.
well, if anybody comes from 4th dimension to our world we hardly understand them.
i think magicians or the illusionists are actually using the fourth dimension. and they dont tell us. they have a very secret society like in harry potter stories.
gods might be living in those dimensions.| supernova1987a wrote: | ||
are you talking about the 4th dimension time or the dimension that is right angle to all the 3 spatial dimensions? take a line in one dimension. draw a line right angle to it and you find the 2nd dimension. draw right angle to both and you find 3rd dimension (like in a cube). draw right angles to all and you get 4th dimension. this is mathematically proven to exist, but since we are trapped in thrid dimension we cannot perceive this 4th dimension. in 4th dimension the universe exists as a hypersphere. and the space of 4 dimensions is called Hyperspace. you shoud read Carl Sagan's Cosmos book, there's something about this that is very interesting. well, if anybody comes from 4th dimension to our world we hardly understand them. i think magicians or the illusionists are actually using the fourth dimension. and they dont tell us. they have a very secret society like in harry potter stories. gods might be living in those dimensions. |
You can't mathematically prove something exists. You can prove that it could exist though.
A 4th spacial dimension (i.e. NOT time) can be constructed mathematically. However, I don't think such a dimension actually exists in our known universe.
It's quite interesting to consider it though!
It's quite interesting to consider it though!
| Dennise wrote: |
| A 4th spacial dimension (i.e. NOT time) can be constructed mathematically. However, I don't think such a dimension actually exists in our known universe.
It's quite interesting to consider it though! |
Actually, the 4th Dimension IS time...
On a 3D or 2D plane, everything is there at on time, 0, right?
But what if something was moving?
| Stubru Freak wrote: | ||||
You can't mathematically prove something exists. You can prove that it could exist though. |
well, it exists anyway.
| Stubru Freak wrote: |
| You can't mathematically prove something exists. You can prove that it could exist though. |
(That's technically true, but not true. You can't mathematically prove that something exists, but you can prove mathematically that it must exist - for example, by proving by contradiction that it can't not exist. For example, conservation laws: we can prove mathematically that they must exist, because if they don't the universe is unstable. In fact, many physical phenomena have been mathematically proven to necessarily exist before they were actually observed.
So you're right: you can't prove by mathematics that something exists, but you can use mathematics to say "if our universe is the way we think it is, then this thing must exist". That doesn't prove that it exists, but if it doesn't then our understanding of the universe is clearly fundamentally wrong. For example, if our universe is stable then conservations laws must exist, so conservations laws might not exist... but if they don't our universe is not stable, which contradicts what we observe.
It's a fine line, yes, but there it is.)
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