BdMO Online Forum

Doraemon has a pocket that is 4 dimensional.
While I was randomly thinking, I saw that,
A 1D line is made up of infinite 0D points.
A 2D area is made up of infinite 1D lines.
A 3D volume is made up of infinite 2D areas.
So shouldn't a 4D figure be made with infinite 3D volumes? If this is true then Doraemon's pocket(which is 4 dimensional) can keep the entire observable universe, can't it? If that's true then wow

Yeah, we are living in a Doraemon's pocket! If there exists another pocket, then there should be a parallel universe there. We have to make a hole in this pocket to go to the other one!

Anindya Biswas wrote: ↑

Wed Jan 27, 2021 4:18 pm

Yeah, we are living in a Doraemon's pocket! If there exists another pocket, then there should be a parallel universe there. We have to make a hole in this pocket to go to the other one!

But to make a hole we need a border, right? But can we reach the border though? I think even with science fiction technology it is impossible to reach a point that is at distance say $k$, where $k \to \infty$.

But wait! Having a border would mean it has a finite volume, wouldn't it? But this contradicts that Doraemon's pocket is 4 dimensional. 4th Dimension is hard to imagine

Mehrab4226 wrote: ↑

Wed Jan 27, 2021 10:33 pm

Anindya Biswas wrote: ↑

Wed Jan 27, 2021 4:18 pm

Yeah, we are living in a Doraemon's pocket! If there exists another pocket, then there should be a parallel universe there. We have to make a hole in this pocket to go to the other one!

But to make a hole we need a border, right? But can we reach the border though? I think even with science fiction technology it is impossible to reach a point that is at distance say $k$, where $k \to \infty$.

I don't think we need a border to make a wormhole. Just like when we can make a hole on a 2D surface, we can also imagine a hole in a 3D universe.

It may be true, that we can make a hole in 3D. But imagining it is totally not an easy task! or at least not easy for me.