all 49 comments

[–]OrphanDidgeridoo 0 points1 point ago

it's the fourth dimension right?

[–]Sabz5150 0 points1 point ago

Correct. That is a tesseract. It is a four dimensional cube.

[–]OrphanDidgeridoo 2 points3 points ago

I wish we lived in a 4D world

[–]1Ra 36 points37 points ago

We do, in fact more like a 10D world. we just perceive the universe as 3D because we have no measurement in the forth dimension.

think of it like an ant (theoretically 2D ant) moving around the floor of an elevator. the ant can only perceive 2 dimensions so it cant tell its constantly moving. while us 3D things would definitely be able to see that the elevator is moving up.

a 4D perceiving organism would look on us the same way, except instead of the elevator moving up and down, more like forward and backward in time.

[–]gilben 9 points10 points ago

I've always wondered if we'd look kinda like spaghetti-like clouds in 4D; more transparent in areas we spent less time, more opaque in areas we spent more time.

[–]Yakone 2 points3 points ago

so what evidence do you have for a 10D world?

[–]wayrell 4 points5 points ago

to my knowledge, you won't find any, it's still hypothetical for the moment. Doesn't mean it's not true of course.

[–]Yakone 5 points6 points ago

We do, in fact more like a 10D world. we just perceive the universe as 3D because we have no measurement in the forth dimension.

Ok. It just didn't sound very hypothetical there.

[–]1Ra 5 points6 points ago

Sweet i got quoted.

[–]zlozlozlozlozlozlo 5 points6 points ago

Inb4 string theory is just a theory.

[–]DisRuptive1 12 points13 points ago

Inb4 String Theory is just a hypothesis.

[–]joejance 1 point2 points ago

This. String "theory" still has many problems and absolutely NO evidence backing it. It could be true, but we just don't know.

[–]wayrell 1 point2 points ago

A theory is still a nice place to be. What's above it in scienc BTW? A paradigm is still a theory.

[–]PirateINDUSTRY 2 points3 points ago

There is math involved there. It's related to superstring theory. They were looking for 6 "rolled up" dimensions (in addition to our 3) and they found 11 total dimensions. From what I'm to understand, it's not really explainable without knowing the maths.

Michio Kaku Hawking also mentions this as well as Brian Greene.

[–]zlozlozlozlozlozlo 2 points3 points ago

The question was about evidence.

[–]Yakone 0 points1 point ago

string theory? I think (I'm not a physicist) that it string theory and M-theroy are still very tentative, without much supporting evidence.

[–]OrphanDidgeridoo 3 points4 points ago

oh shit. Since the universe is flip floppin' hardcore, hella dimensions, but to us we're just on a sphere. Lol.

[–]PovertyPoint 0 points1 point ago

That shit just rocked my mind.

[–]rotishoti 0 points1 point ago

How do you know that time is the 4th dimension?

[–]zlozlozlozlozlozlo 2 points3 points ago

If you have a certain event in mind, you need 4 numbers to locate it: 3 spatial dimensions and one temporal. That's as simple as that.

[–]ftardontherun -2 points-1 points ago

Dimensions are a theoretical construct, so time is the 4th by definition. We could just as easily say banana is the 4th dimension if we wanted to define it that way.

[–]1Ra 1 point2 points ago

I don't know exactly how it was discovered, but time is the 4th dimension. I do know that it was partly found out by how time can be effected by multi-dimensional forces like gravity or vacuum.

but i can say for sure its not bannana.

[–]ftardontherun -1 points0 points ago

Proof? ;)

[–]zlozlozlozlozlozlo 1 point2 points ago

We could just as easily say banana is the 4th dimension

Huh?

[–]ftardontherun -3 points-2 points ago

Asked

How do you know that time is the 4th dimension?

By definition. You can define anything to be anything.

[–]zlozlozlozlozlozlo 1 point2 points ago

That's just silly: the meat of the question is why is that a good definition.

[–]ftardontherun 0 points1 point ago

Oh sure. It makes a certain amount of sense, but it's not obvious. What I mean is it could have been defined differently. I don't think there are many people who understand it well enough to make a good case for why it should be, and not the fifth or 10th or not a dimension at all.

[–]marco161091 0 points1 point ago

What chipbuddy said. Basically a dimension is a "direction" we can travel in. And after front-back, left-right, and up-down, time's the last.

[–]chipbuddy 0 points1 point ago

Lets start with explaining why the statement "time is a dimension" is a silly thing to say. We're familiar with 3 spacial dimensions. Generally we can move freely through them. By turning left onto main street we suddenly go from a north/south direction to an east/west direction. We can also adjust our speed by applying the break or hitting the gas. Finally (and this is a little less obvious) the more we travel in one spacial dimension the less we travel in another.

To explain this last part, let's say we're traveling in a car going exactly north at 100 kph. Lets say we turn to the north-west but keep our speed constant. We're now traveling to the north at about 71 kph and to the west at 71 kph. If we take those two components together (using the Pythagorean theorem) we find we're traveling to the north-west at (about) 100 kph.

If we turn completely to the west, we're now traveling at an overall speed of 100 kph, to the west at 100 kph and we've completely stopped traveling to the north.

Right, so time isn't like the above at all. Namely, we can't freely travel forward and backwards through time, we can't adjust our speed through time and traveling faster in spacial directions doesn't rob us of our speed in some confusing "time" direction. On an intuitive level, time is nothing like spacial dimensions.

Unfortunately, in the 20th century Albert Einstein came along and took a bit steaming shit on our intuition and he called it "special relativity".

It turns out (this may sound like a hand wave, but humanity has done lots and lots of experiments to directly observe the following weirdness) we can adjust our "speed" through time and traveling in any spacial direction robs us of our speed through that time direction. Unfortunately we can't travel freely backwards through time... but objects that do travel backwards through time have been predicted and the properties of these objects don't directly contradict anything we've observed.

I can't go into the specifics of special relativity or exactly why special relativity is true. However I can say that special relativity is the most accurate set of rules we've been able to come up with to explain the world around us.

In summary, the faster you move through the normal spacial directions, the slower you move through the time direction. When you are completely stopped you speed along through time at a rate of 1 seconds per second (you read that right). When you travel at near the speed of light (a cosmic speed limit) you travel through time at nearly 0 seconds per seconds (again, you read that right). To put that another way: Some person not speeding along will observe you moving very fast and see that your clocks are ticking very very slow.

Spacial directions and time are so similar that treating them both as spacetime makes reasoning about the universe a whole lot easier.

[–][deleted] ago

[deleted]

[–]ftardontherun 0 points1 point ago

All by definition. Can you prove to me that time must be the fourth dimension? Not as simple as it seems - I think you'd likely need an advanced degree. Yes, I was being a bit silly, but the point stands. Relativity is based on accepted definitions.

[–]alkaline810 -1 points0 points ago

As Brian Greene explains, think of each dimension as a coordinate. If you want to meet someone at a certain time and place (say, building at the South West corner of 1st and Main St., 3rd floor, 4:50pm on Friday) you need to specify 4 dimensions in spacetime (x,y,z plane and time).

The other 6 are wrapped up; something which I have yet to fully grasp.

[–]redaniel 0 points1 point ago

Can I give up on one dimension in order to have more time ?

[–]kyoujikishin 0 points1 point ago

The only problem I have with that is the "folding" of axes. Yes a unit can move between two spots on an N-dimension by moving through the N+1 dimension, but that doesn't mean or insinuate that the N dimension folded.

[–]YesItIsTrue 0 points1 point ago

a 4D perceiving organism would look on us the same way, except instead of the elevator moving up and down, more like forward and backward in time.

This is not what a physical 4D is like. People say time is the 4th dimension, but it is not. I can kind of see physical 4D, but only from a 3D perspective.

[–]1Ra 0 points1 point ago

That was the point i was kind of going at.

the same way a 2D creature could only perceive 3D us from a 2D perspective.

[–]YesItIsTrue 0 points1 point ago

OK, cool. I just want to divorce the 4th dimension from time, which is usually how people perceive it.

But anyways, I can definitely see 4D from our 3D perspective, sort of. Aren't I cool? (fishing for compliments, here, throw me a bone.)

[–][deleted] 0 points1 point ago

Unless the elevator had windows, no we couldn't. We'd be able to feel the elevator move, but even then we'd not be able to distinguish it from a perceived gravitational field.

That said, we'd be aware of a third dimension, because we can distinguish the ceiling and the floor of the elevator, something the ant cannot.

[–]mybustersword 0 points1 point ago

http://www.youtube.com/watch?v=8Q_GQqUg6Ts all of that is answered here

[–]OgGorrilaKing -2 points-1 points ago

[–]dazzlie1 0 points1 point ago

Technically, it is the shadow of a four-dimensional cube moving, in the same way the shadow of, say, an apple changes shape as you turn it.

[–]theveldt01 0 points1 point ago

I would swear this thing is going to the left of my screen.