You build your track dead straight - like, not conforming to the surface direct through the crust straight. Now the train accelerates downhill for the first half of the journey, and decelerates uphill for the second, neatly coming to a stop at the destination. Oddly enough, in the spherical cow universe where you build this, all the maths cancels such that you get a constant travel time regardless of the start and end locations. On earth it's about 40 minutes
If you accelerate the passenegers to the same speed as the train while they board, then you can solve one of those problems. I suggest firing them out of a canon.
Keep the ideas coming guys, this is a great brainstorming session. I think you have solved most of the practical issues. I'll talk to the investors, but I think WE are almost there!
On a related note, everyone in the R&D department is being terminated.
What if we figure out a way to safely transport people IN something like a missile, self propelled, and can be launched on a schedule. Then we wouldn't need the train at all!
Missiles are super inefficient. You have to overcome gravity while fighting air resistance at the same time, which requires unreasonable energy density
If only there was some way to use air resistance to fight gravity, or better yet even some sort of metal road to push against to lower required acceleration to the minimum...
Maybe if we made a super slow missile on rails? Never mind, this sounds crazy now that I say it out loud
I was assuming the rails are strong enough to keep the train on the Earth, but I guess infinite friction from the movement and rotation of the Earth probably isn't survivable by any railway material. Hypothetically, if you had a material unaffected by gravity (train), and a material that is absolutely invincible (the rails, and they are anchored to the center of the Earth), now does it work?
No, the problem is not gravity, is that the train attached to earth has velocity dictated by the Earth movements, and keeps it because of inertia. In your theoretical experiment, the train would be launched on space at constant velocity.
The problem isn't gravity, it's friction. The train would functionally be in orbit. The reason why things can't be in orbit at ground level is not because of gravity but because of friction (incl. air resistance).
If you eliminated friction (vacuum tube, frictionless surface, etc.) you could indeed have the train moving without any additional energy after getting it up to speed (and if you get it up to orbital speeds, the frictionless surface isn't even necessary). However, this isn't really practical (obviously).
If there is a nugget of a good idea in here, it's a train that never needs to accelerate or decelerate, just maintain a constant speed. Much of the energy of a train is lost in the stop-and-start.
25 Comments
superkret@lemmy.ml · 107 pts · 2y
This actually works. All you have to do is decelerate the train once (because it's spinning with the world while you build it).
And solve the trivial engineering task of reducing all friction and air resistance to zero. Oh, and that of getting on and off the train.
mrbubblesort@kbin.social · 53 pts · 2y
Well shit, anyone can do that. Just put a little WD40 on it
MashedTech@lemmy.world · 4 pts · 2y
(シ_ _)シ
octoperson@sh.itjust.works · 12 pts · 2y
You build your track dead straight - like, not conforming to the surface direct through the crust straight. Now the train accelerates downhill for the first half of the journey, and decelerates uphill for the second, neatly coming to a stop at the destination. Oddly enough, in the spherical cow universe where you build this, all the maths cancels such that you get a constant travel time regardless of the start and end locations. On earth it's about 40 minutes
Zeth0s@lemmy.world · 9 pts · 2y
You need energy to decelerate, though.
superkret@lemmy.ml · 30 pts · 2y
Just use magnets.
Pls send my Nobel price by mail, I'm not good at speeches.
Zeth0s@lemmy.world · 12 pts · 2y
Fridge magnets are the secret of infinite energy
Jumuta@sh.itjust.works · 3 pts · 2y
you could conceivably get on and off the train with shuttle "station" trains that travel on parallel tracks to catch up with the main train
magnetosphere@kbin.social · 68 pts · 2y
I think I had this idea when I was ten. I knew I should have patented it. Fuck.
DrCatface@lemmy.ml · 13 pts · 2y
I swear I came up with the iphone... my design was a triple flip phone, screen up top, keypad in the middle and an ipod wheel down bottom
GrammatonCleric@lemmy.world · 60 pts · 2y
Why? Because fuck physics, that's why!
Blastasaurus@lemm.ee · 52 pts · 2y
Just tie it to the moon.
chemical_cutthroat@lemmy.world · 13 pts · 2y
It's a high tide train ride!
NorthWestWind@lemmy.world · 5 pts · 2y
Ride the tides then
PropaGandalf@lemmy.world · 5 pts · 2y
Or to the sun
amanneedsamaid@sopuli.xyz · 9 pts · 2y
This would be possible if there was a material unaffected by gravity, right?
normanwall@lemmy.world · 29 pts · 2y
Enkers@sh.itjust.works · 11 pts · 2y
If you accelerate the passenegers to the same speed as the train while they board, then you can solve one of those problems. I suggest firing them out of a canon.
drolex@sopuli.xyz · 6 pts · 2y
Keep the ideas coming guys, this is a great brainstorming session. I think you have solved most of the practical issues. I'll talk to the investors, but I think WE are almost there!
On a related note, everyone in the R&D department is being terminated.
necromancyr@lemmy.world · 3 pts · 2y
What if we figure out a way to safely transport people IN something like a missile, self propelled, and can be launched on a schedule. Then we wouldn't need the train at all!
SterlingVapor@slrpnk.net · 5 pts · 2y
Missiles are super inefficient. You have to overcome gravity while fighting air resistance at the same time, which requires unreasonable energy density
If only there was some way to use air resistance to fight gravity, or better yet even some sort of metal road to push against to lower required acceleration to the minimum...
Maybe if we made a super slow missile on rails? Never mind, this sounds crazy now that I say it out loud
comrade19@lemmy.world · 2 pts · 2y
What if someone got on every time someone got off
amanneedsamaid@sopuli.xyz · 1 pts · 2y
nucleative@lemmy.world · 9 pts · 2y
I think in that case, the earth would just depart the location of the train, leaving it drifting in space.
amanneedsamaid@sopuli.xyz · 2 pts · 2y
I was assuming the rails are strong enough to keep the train on the Earth, but I guess infinite friction from the movement and rotation of the Earth probably isn't survivable by any railway material. Hypothetically, if you had a material unaffected by gravity (train), and a material that is absolutely invincible (the rails, and they are anchored to the center of the Earth), now does it work?
AeroLemming@lemm.ee · 1 pts · 2y
Zeth0s@lemmy.world · 7 pts · 2y
No, the problem is not gravity, is that the train attached to earth has velocity dictated by the Earth movements, and keeps it because of inertia. In your theoretical experiment, the train would be launched on space at constant velocity.
Drewfro66@lemmygrad.ml · 4 pts · 2y
The problem isn't gravity, it's friction. The train would functionally be in orbit. The reason why things can't be in orbit at ground level is not because of gravity but because of friction (incl. air resistance).
If you eliminated friction (vacuum tube, frictionless surface, etc.) you could indeed have the train moving without any additional energy after getting it up to speed (and if you get it up to orbital speeds, the frictionless surface isn't even necessary). However, this isn't really practical (obviously).
If there is a nugget of a good idea in here, it's a train that never needs to accelerate or decelerate, just maintain a constant speed. Much of the energy of a train is lost in the stop-and-start.