system
Given the following post, respond as if you're commenting on Reddit:
human
Is there a reason we can't just build an incredibly long tube to get liquids such as water or fuel into space?

It seems to me like that would cut costs dramatically if you were able to build something long and strong enough. 
I imagine The issue is building something with both the length AND the strength to accomplish the task. Or is there another reason?
gpt
Pressure increases with the height of fluid in the column. So if we use the formula:

 roh x g x h 

and the fact that low Earth orbit begins at 160 km and ends at 2000 km (just googled that), we can calculate the pressure at the base of the column, no matter it's diameter.

so we get (for water):

1000 kg/m3 x 9.81 m/s2 x 160,000 m

Which is: 1569600 kPa or 227,651 psi.

Good luck making a tube that can withstand that kind of pressure at its base and also support a structure reaching that far up.