# How can this teleporter escape from eternal falling? [closed]

Let's say we have a teleporter, whose teleports obey conservation of momentum. I.e. if they are moving, and they teleport, then they will continue moving in the same direction. The have no hard range limit, but due to conservation of the earth's rotation will generally make it dangerous to carry out teleports over very long distances.

One day they get into the situation where they are constantly falling at terminal velocity, and are having to repeatedly teleport into the air to prevent themselves from splatting into the ground.

What methods could they use to escape this situation?

• It seems like you have a character, a set of rules for your world, and a scenario, but instead of asking about how to better flesh out your world you're asking how your character can overcome a problem you've chosen to construct for them. Such questions aren't a good fit for this site. Commented Apr 1, 2022 at 15:11
• Well it's asking about how to construct the receiver of a long range teleporter safely.. but I admit there are close reasons, I'll ctv along. This could be closed for other reasons as well.. there's quite a lot of duplicates I'm afraid.. @blademan9999 click my link to search, you posed a popular question, there's probably a lot of answers to find here. Commented Apr 1, 2022 at 15:35
• What are they moving relative to? Earth's rotation? Earth's orbit around the Sun? The Sun's orbit around the galaxy? The galaxy's motion relative to the cosmic background radiation? They had better not make any navigation errors at all or they could end up underground and cause a nuclear explosion sufficient to destroy the Earth. Commented Apr 1, 2022 at 21:47
• @user676 Because they'd still be falling at terminal velocity. Commented Apr 2, 2022 at 5:06
• @user6760 the acceleration is terminal velocity to zero within microseconds in both cases.
– John
Commented Apr 3, 2022 at 20:17

If their range and precision allow, they can teleport on the opposite side of the Earth (the height will influence air pressure: teleport ten kilometers too far, and you'll find yourself in the stratosphere, and die of pressure shock, cold and/or oxygen starvation). This way, gravity itself will act as a brake.

Otherwise they could teleport horizontally around the Earth, provided they can do so at a high enough rate that the build-up of normal velocity does not nullify the effort. Their speed will remain the same, but its direction will slowly vary in respect to the surface.

Actually, since their velocity (with respect to the center of the Earth) is about 200 km/h vertically, and 1000 km/h horizontally due to rotation, teleporting to a place about 30 degrees rotation-ward will transform a part of those horizontal 1000 km/h into an upward component, partially negating the descent speed. It should be possible (height control is still paramount, because of pressure/oxygen) to find the best distance by trial and error.

Something like this happens in Vernor Vinge's The Witling, even if the people involved are inside a capsule that is being teleported.

Update: actually, the "teleporting to the opposite side of the planet" will not work. This is a plot point in Vinge's novel: people able to reng (teleport) air from the opposite side of the world can make people here experience the airspeed of the opposite side of the world – and use this as a weapon. Teleporting and suffering an air blast at Mach 3 will be instantly lethal. Possibly, even the drag acceleration will be enough to make the teleporter lose consciousness, at which point they'll naturally fall down to their death.

Failing this, they need to shed velocity in some way. There are no safe ways of doing so; maybe the least bad option is to teleport above a lake. A terminal velocity impact on water is survivable, if harmful, if one has time enough to prepare (you need to achieve a high, but regular, deceleration). Also, terminal velocity (around 200 km/h, equivalent to a fall from a height of about 450 m) can be decreased even substantially, e.g. if one can arrange one's garments in the form of a funnel. Only in Hollywood movies could someone have the presence of spirit and speed for doing this, but our transporter could do this in stages. Possibly, transporting themselves fifty meters higher as soon as they feel the impact could spread the damage in two "installments", so to speak.

A very deep snowy incline would also work (there are reports of people falling from kilometer-more heights over snow and surviving. Vesna Vulovic famously survived a fall of more than 10 km after her airplane was destroyed by a bomb).

# update: teleporting rotation-wards

TL;DR: it... could... work!!!

I have run some Geogebra simulations. When teleporting from point B to point C, separated by an $$\alpha$$ angle on the rotation plane, the two velocity vectors $$u$$ horizontal (due to rotation) and $$v$$ (due to the initial fall) remain unchanged, but their orientation relative to the surface changes their "meaning". In the new position, the fall is reduced to vector $$b$$, which is $$v \cos \alpha$$, diminished by the new "vertical" component of the rotational velocity, $$a$$, which is $$u \sin \alpha$$. So the new fall velocity is $$(v \cos \alpha - u \sin \alpha)$$.

For a terminal velocity of 200 km/h and rotational velocity of 1000 km/h, we want $$200 \cos \alpha = 1000 \sin \alpha$$, which means an $$\alpha$$ of $$\arctan(0.2)$$ will make the two components neutralize one another. I had estimated this to happen for an alpha of 30 degrees; it is actually 11.31 degrees, or a distance of about 1200 km (in the picture the two velocities are closer together, so it seems that the correct angle is double that).

What happens to the horizontal velocity when teleporting 11.31 degrees rotation-ward?

The new vector is the sum of vector $$w$$ and vector $$d$$, where $$w$$ is $$v \sin \alpha$$ and $$d$$ is $$u \cos \alpha$$.  This gives $$200 \sin 11.31\unicode{xB0}$$ plus $$1000 \cos 11.31°$$, or $$39.22 + 980.58$$, or about 1020 km/h.

So after the "right" teleport our vertical velocity is completely neutralized and we find ourselves going up a wind of 20 km/h, which is tolerable (cue thunderclap).

This can also be done with about ten jumps towards the horizon (which at an altitude of 1 km is about 110 km distant); this is desirable because a visual check of the reentry altitude is better (if you rematerialize at a very different altitude, the difference in air pressure is likely to be nasty). Each jump will experience a slow-down in the fall speed and a slight head wind.

After this, shorter and faster jumps rotation-wards will pull the teleporter "up" and allow to fine-tune a safe descent.

In the case of terminal velocity, the time taken by the teleport is irrelevant, because during this time the fall speed does not increase (since it is "terminal"). So, the teleporter may refine their range by waiting each time until they've built terminal velocity, and then jump (to build terminal velocity, a fall of about 450 m is enough; it takes around 12-13 seconds).

But even if this were not the case, it would not be a great matter; all that would be needed is to take the extra speed into account (i.e. design the jump to neutralize not the current velocity but the one that will be reached at jump time, in, say, three more seconds).

On the other hand, this means that once they've stopped their vertical motion, they need to land very quickly before building up more speed. So they want to be, say, high above water; at that point they teleport straight down, as near the surface as they can.

# honestly

Determine spinward direction (possibly by trial and error, making jumps with a small horizontal component and seeing what happens), then start making longer and longer (or faster and faster) jumps to and fro, in the direction where you feel wind at an angle of about 5° from the vertical. This wind will become less and less, and more and more far from the vertical, when approaching the "ideal jump". If the jump does not work, jump back to the original position, some distance higher, and retry. The horizontal component will not have changed much and will be soon compensated, and the vertical will have remained the same also, because you're falling at terminal velocity.

While doing such jumps, endeavor to reduce your altitude to take advantage of the denser air, and see if you can spot a suitable body of water. If none is found, teleport higher in the new position; soon you'll be falling at terminal velocity there too, and you can restart the whole process 1200 km to the east. At most after twenty such iterations you're bound to find water: at worst, the Pacific. Once you splash down, you can play human skipping rock going west, in shorter jumps, each time letting the water neutralize the small speed gained in the jump, until you are safely near a beach.

To further reduce speed you can try and get off e.g. the trousers or jacket and fashion a small parachute. The goal is to lower airspeed as much as possible, which allows shorter and more precise jumps.

# cheating

Teleportation comes with a sense of matter – in the Vinge novel above, the Azhiri can "seng" around them and so have a "feel" for the volume of space they'll swap into. This sense, this instinct, also extends to speed – your teleporter can "feel" the relative tranquility of a given volume of space, and won't teleport onto a hurtling train. The discomfort sensation is greater the higher the speed differential.

Evaluation of a volume is then easy and instantaneous, in the same way that we can examine a vast area of space and immediately and effortlessly pinpoint the place with the highest photon reflectance in a given interval of energies – a task that would appear impossible to someone who had never heard about the sense of sight.

So, the teleporter keeps teleporting in places where the unease is just right, waiting for the sense of unease transmitted by the solid ground to abate; when this happens, they'll just teleport on the safe area on the ground they perceived.

The difficulty is then apparently enormous, but to a teleporter is no more difficult than it would be, for us, finding a suitable shade of green on a continuous thermal map, even if the map would change after each jump:

• Opposite side of the Earth is a bad idea. Sure, your "down" vector is transformed to "up" and in a minute or so you'll be as high as you're going to get, but depending on your latitude, you'll arrive with a horizontal airspeed between a few hundred km/h and Mach 2.5+ -- the latter especially is very bad. Commented Apr 1, 2022 at 11:58
• @ZeissIkon yes, I had realized it after I took some time remembering Vinge's novel :-) - and then I came out with the "angle" theory. Haven't had the time to check my numbers yet, as I'm having WAY more pressing problems with my very terrestrial refrigerator endeavouring to thaw my food supplies on the sly... Commented Apr 1, 2022 at 13:39
• Maybe, you could shed some lateral speed by teleporting repetitively towards the poles and once over the poles, you can do the "go to the opposite side of the planet to shed speed" thing. Commented Apr 1, 2022 at 16:05
• Neat approach. Interesting to note that the angle to teleport will depend on the horizontal speed, determined by latitude at which you're falling. If you're falling above the north pole, you have zero rotational velocity, so the updated approach won't work, but teleporting above the south pole with the original approach will work just fine. Commented Apr 1, 2022 at 17:04
• All the incremental teleport solutions ignore the fact that as you're shedding horizontal velocity, your vertical velocity is building on the new "down" vector. This one, however, might work due to the geometry. Commented Apr 1, 2022 at 18:19

Live falling.

You are not going to stop falling. You will wander the upper reaches of the earth, falling. You will want to fall through rainstorms with your mouth open to drink. You will want to fall through migrating birds and catch some on your way through, to eat.

Your hair will become long, trailing behind you. Your clothes will eventually become rags from flapping in the wind. People in the tropical locales you frequent (it is cold with just flapping rags on!) will come to recognize you and wave and shout when you appear high in the air. You wave and shout back. You get close to the ground before you disappear because you want to see what they look like.

Some of your new friends get kites out when they see you and you eventually learn what that means - kite cookies! You maneuver over to snag some off the kite. Delicious kite cookies.

Then you find a message on the kite. You don't read Tongan but there is a picture of you (you can tell because of the 3 feet of hair blowing behind you) and you are holding the cookie kite in the air. Could the cookie kite slow you down enough to splash in the water? The people are watching the first time you try. The kite is torn to shreds before you disappear.

The second kite is much bigger and flies much higher. It has a long tail. A lot of people are watching. On the first pass you get the cookies then retreat higher in the sky to eat them and fortify yourself. On the second pass you make a grab for the tail of the kite...

• This is the most fun answer so far +1 Commented Apr 2, 2022 at 3:41
• You could take this even further - at some point you meet a friendly and attractive teleporter of the opposite sex in a similar predicament. The two of you hook up, start a family of teleporting children who also can never land, you live happily ever after until you both die of old age. (Inspiration stolen from one of the Zork games, only that involved a bottomless pit instead.) Commented Apr 4, 2022 at 13:32
• While awesome, you'd have to sleep at some point 🙂. Commented Apr 5, 2022 at 15:48
• Works till you need to sleep. Commented Sep 7, 2022 at 15:56

Your teleporter needs to locate a thunderstorm.

The updrafts that create the anvil cloud in a strong storm can be sufficient to lift a skydiver in spread eagle (especially if wearing loose clothing). Get into that updraft and it will greatly slow the fall, possible stop it entirely. The trick will be, with near-zero visibility, determining when this has occurred, because he'll still be falling at around 140 km/h relative to the air and cloud even when he's stopped relative to the ground.

A teleporter, though, should have some senses normal humans don't (otherwise, he'll be dead long before this situation arises), so presumably he'll either be able to sense his velocity relative to Earth's surface, or at least his altitude, so as to know just when to 'port to ground (a small upward or even downward velocity isn't a big problem -- a couple m/s will result in a little "hop" or be absorbed by knee flexion).

• And if you're still moving upwards, when you teleport to the groun, then that's easy, just teleport to the ground again an again. Commented Sep 7, 2022 at 15:57
• True, @blademan9999, but if you're not sure of your velocity, what if you're falling at 60 km/h instead of rising at the same rate? Commented Sep 7, 2022 at 16:20

Your problem for slowing down is finding something airborne which gives you friction. So...

### Teleport to a waterfall

Ideally one that has a long vertical drop. Angel Falls would be perfect. Now however fast you're going, the water is also falling - and its terminal velocity is not going to be too dissimilar to yours. So you can hit the lower half of the waterfall to scrub off any extra speed, then teleport a bit higher (where the water is falling more slowly) and scrub off speed there, and keep on doing this until you're not falling much faster than the water maybe 10m from the top of the waterfall. At which point you're going slowly enough that simply jumping into a pool (I'd teleport down to just above a pool at the bottom, because it's deeper) is perfectly safe.

• That's the minecraft solution ;-). Commented Apr 3, 2022 at 23:02
• @Peter-ReinstateMonica Kind of, except with physics. :) Commented Apr 5, 2022 at 10:21

## Phone a Friend

Literally. If there is someone else with a comparable ability, have them come to the rescue. Remind them to bring 2 parachutes.

Heck, you might want to get into the habit of bringing along a parachute at all times (to preempt this sort of thing).

Why not just, teleport themselves upside down?

To cancel their momentum?

Step 1: teleport to other side of the planet, above any hard object.

From falling down at terminal velocity and eastward with Earth rotation (460 m/s at the Equator) they will find themselves going up with terminal velocity and westward at 920 m/s.

Gravity will slow them down for the upward motion, and air drag will take a toll on them for the horizontal velocity (I hope they are not in t shirt and shorts).

Step 2: when their vertical velocity has gone close enough to zero, they teleport back to where they started from, or closer to ground.

They will have an almost 0 vertical velocity and an horizontal differential velocity equal to the amount they have lost due to drag.

• "They will have an almost 0 vertical velocity and an horizontal differential velocity equal to the amount they have lost due to drag." And considering how many times faster the treminal velocity they'll be moving as well as how long they'll stay before teleporting back, that velocity figure will be quite large. Commented Apr 1, 2022 at 12:04
• I'm afraid that will not work (I had thought of that instinctively, too): 920 m/s is almost Mach 3, and teleport will deliver an acceleration in excess of anything humanely survivable. Teleporting at a shorter range so the velocities compose to something tolerable ought to work. Commented Apr 1, 2022 at 13:44
• They'll be dead after hitting a windstream at nearly Mach 3. Likely torn apart, certainly a naked corpse, unless they're wearing a high altitude pilot's pressure suit. Even that suit won't save them from the accleration due to drag. Commented Apr 1, 2022 at 14:01

Teleporters would have a variety of responses to this potential problem.

# Try to find a soft surface to land on.

Snow or dirt hills are good. A soft plant to land on is ok. You want something that compresses and displaces well. If you can prep, you can make a large bale of hay. This means you can hit at terminal velocity and not die. Water isn't really safe.

If you have a friend you can also ask them to make a big pile of hay or grass for you to land on.

Kill a bird or several and use them as a makeshift parachute, ride air updrafts, there's a bunch of ways you can bleed off some speed. It doesn't have to be great, but a lot of these methods are easier if you lose some speed.

# Slow yourself down by grabbing something.

Using some sort of metal thing and a vertical surface like a cliff, you can slow yourself down. Scratch the metal against the surface and the friction between it and the surface could slow you down. If you can find a long rope you can also grab onto that and use the friction to slow yourself down. If you have a friend in a castle, you could ask them to lower a rope down off the edge of a wall and grab onto it as you fell.

# Escape into the afterlife.

If none of this is working or feasible, just pick someone you hate and hit them at escape velocity. Both of you will die, and you can go to the afterlife, which will hopefully end your terminal velocity.

• if you're falling at terminal velocity and grab a robe, your hands will be flayed immediately. Sliding down a rope with a starting velocity of 0 can be painful enough, if you do that at terminal velocity, your skin will practically evaporate. Commented Apr 3, 2022 at 17:28
• @PixelMaster agreed, and imo the rope stuff really hurts the credibility of the rest of the answer, in particular the bird parachute. Commented Apr 9, 2022 at 1:57
• It sucks to flay your hands, but it also sucks to smash on the ground and die. Commented Apr 9, 2022 at 19:08

If they are falling, but momentum is conserved, can you aim the teleport so it launches them directly upwards? Their momentum will keep them heading up until gravity slows the ascent. Then they want to teleport to the ground before gravity yanks them down into another fall.

Depending on their accuracy and knowledge of the area this can be a long shot, especially considering that without protective clothing you will likely freeze to death quickly.

Go to Hollywood or your nearest large movie production center and find an area where they have stuntman cushions, the ultra-fat one's meant for people who jump from high elevations. Land on one.

You will likely be harmed and might still die, but there is a good chance you'll survive. There have been cases of people surviving being thrown/jumping out of an airplane because they landed on thick bushes or something similar. They too were worse for wear, but alive.

• This will be fatal. He's going to fall at the rate a skydiver does, Once a daredevil has landed with neither parachute nor even wingsuit, in a net with a very deep breakaway system to give non-lethal acceleration. Your teleporter can't depend on finding one of those, and air bags or stacks of cardboard boxes won't suffice. Commented Apr 1, 2022 at 16:23
• @ZeissIkon people have survived in worse conditions: en.m.wikipedia.org/wiki/…. Power lines, snow drifts, even glass roofs helped them survive. As I said, it wont be a pretty fall and you will likely be harmed, but your chances of survival skyrocket. Commented Apr 1, 2022 at 16:51
• Sure, people have survived -- once or twice by each method, out of all those who haven't. That's not enough to say such an impact wouldn't be fatal; it'd be like saying rabies isn't fatal after 2 people in history have lived through it (and neither was very functional after, as I recall). The teleporter would surely rather have better odds than that. Commented Apr 1, 2022 at 17:37
• @ZeissIkon the big difference here is that it goes from "will be fatal" to "might be fatal". And considering that you are looking for a set of circumstances exactly like a Holywood mattress, an item designed to slow your descent over time to reduce the final impact, its a good candidate. Its not a guaranteed survival and as said you'll likely be beat up, but in my estimate you would survive more often than not, assuming you can take on a proper position to land in. Which is likely since you gave time to change position. Commented Apr 1, 2022 at 19:07
• Still disagreeing. Those air bags are for falls of, at most, under 100 feet, and even at that height it's considered risky by the stunt community. Terminal velocity has you hitting at more than twice the speed, 4x the energy. There has never been a stunt air bag made that will make a terminal velocity landing survivable. Survival from that speed is a "freak" or "fluke" not something you can even give odds for. Commented Apr 1, 2022 at 19:26

Teleport to the other side of the planet

The teleporter fails at long distances because the Earth rotates on its axis. You move with the surface. So even if you stand still on the equator you are moving along the equator direction at 460 m/s. It you teleport to the other side of the planet you will appear and find the ground moving beneath you at 920 m/s. Splat.

But by the same token, if you were shot out of a cannon at 920 m/s at the equator, you could save yourself by teleporting to the far side of the planet, where the ground is moving the same speed as you are, and land safely.

The trick to cancel fall damage is the same. Teleport to a place where the Earth is moving in the same direction to you. Or at least where the surface velocity is closer to your current velocity.

Deciding exactly exactly where to teleport is a job for a computer. We likely need to make many jumps to somewhere far above the surface, fall for a while, and then port to the next place.

Take a helmet, and a sturdy bodysuit, and teleport into a large body of water.
Or make sure to teleport feet first.

Catch an airplane!

Call the famous energy drink company and have them send an airplane that lines up with you so that you can "wingsuit" into the open airplane door. Your airspeed will be higher than in the video because you probably don't have a wingsuit but you can try until you succeed because of your teleporter. Eventually you'll pop in.

Actually, depending on the precision the teleporter is capable of, you can probably simply line up with the airplane and teleport inside. No need to hit a door.

Frame challenge: you have way bigger problems than the terminal falling velocity. To put it into perspective, these are the velocities which a person teleporting would be subject to according to your rules...

• 200 km/h terminal falling velocity
• 1000 km/h rotating speed of earth
• 108000 km/h earth rotating around the sun
• 792000 km/h sun rotating around the galaxy center
• 3600000 km/h or more he galaxy moving...

To me it looks like you will need to bend the conservation-of-momentum rules somewhat, otherwise your teleporting people will be in big trouble in all but the most trivial cases...

• And the last three are the same no matter where you are on earth. Commented Apr 4, 2022 at 12:10