this post was submitted on 05 Oct 2023
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[–] [email protected] 102 points 2 years ago* (last edited 2 years ago) (5 children)

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.

[–] [email protected] 12 points 2 years ago (1 children)

And solve the trivial engineering task of reducing all friction and air resistance to zero.

Well shit, anyone can do that. Just put a little WD40 on it

[–] [email protected] 3 points 2 years ago

(シ_ _)シ

[–] [email protected] 11 points 2 years ago

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

[–] [email protected] 10 points 2 years ago (1 children)

You need energy to decelerate, though.

[–] [email protected] 29 points 2 years ago (1 children)

Just use magnets.
Pls send my Nobel price by mail, I'm not good at speeches.

[–] [email protected] 14 points 2 years ago

Fridge magnets are the secret of infinite energy

[–] [email protected] 3 points 2 years ago

🤔 A vacuum tube maglev would do the trick.

Actually Isaac Arthur talks about something like that on his channel. An Orbital Ring, he calls it.

[–] [email protected] 3 points 2 years ago

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

[–] [email protected] 58 points 2 years ago (1 children)

Why? Because fuck physics, that's why!

[–] [email protected] 53 points 2 years ago (3 children)
[–] [email protected] 14 points 2 years ago

It's a high tide train ride!

[–] [email protected] 6 points 2 years ago

Or to the sun

[–] [email protected] 5 points 2 years ago

Ride the tides then

[–] [email protected] 8 points 2 years ago (3 children)

This would be possible if there was a material unaffected by gravity, right?

[–] [email protected] 9 points 2 years ago (2 children)

I think in that case, the earth would just depart the location of the train, leaving it drifting in space.

[–] [email protected] 2 points 2 years ago

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?

[–] [email protected] 7 points 2 years ago* (last edited 2 years ago)

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.

[–] [email protected] 2 points 2 years ago

I think I had this idea when I was ten. I knew I should have patented it. Fuck.