Why would time travel affect the body in any major way, especially damaging? [closed]

Obviously, I'm talking about sci-fi time-travel and not just being as time moves by, slowly but surely. Is there a reason one would actually bleed from any orifice? For any pain to occur? Dizziness? Any general feelings of sickness, or not being well? Take this pill and you'll be fit as a fiddle! No, but seriously.

Any form of time-travel (you decide), as long as it doesn't entirely collapse on itself. Multiple timelines seem go-to, no? Maybe... I personally can't see why it would physically affect you (psychologically, that I can see), but I'd love to know if there could possibly be a few reasons.

Hopefully to clear up: I don't know yet how it would work, the time travel. That would depend on how the damaging of the body could in fact work. I'm working from it backwards, if you will. Would be ideal, but definitely not necessary, for the ill-effects to be permanent for the user. Hope that clears up any questions. If you're looking for how the time travel would work, I'm pretty much leaving it up to how you think it would need to be for it to be damaging to the body.

(In the story, the emphasis is put on the physical effects of time travel, rather than the time travel itself.)

Many good questions generate some degree of opinion based on expert experience, but answers to this question will tend to be almost entirely based on opinions, rather than facts, references, or specific expertise. If this question can be reworded to fit the rules in the help center, please edit the question.

15 Answers
15

No form of time travel i know of is well explained in terms of the nitty-gritty of what is actually going on. Some don't say anything about the mechanism, others introduce weird 'rules' (Terminator: can't wear clothing?) without exploring their underlying restrictions.

Some of the effects you mentioned can be explained rather easily, though:

Dizzyness is a common problem even without time-travel. Many adolescent and elderly people suffer it thanks to problems in blood pressure control, and it is also a widespread problem associated with sea voyages: Here it's a complex interaction of the 'normal' as perceived by the inner ear (direction of acceleration/gravity) vs. 'normal' as perceived by other means, i.e. the visual perceprion of a horizon.

Bleeding from orifices is also something that happens naturally, when the
blood vessels in mucous membranes (lining all orifices) burst due to problems in blood pressure regulation, or due to damage to the mucous membranes through drying or mechanical interaction.

Pain - again, this is something easily triggered, by microscopic damage to cells - either directly to nerve endings, triggering them, or to cells surrounding nerve endings, releasing substances that then trigger the nerve endings.

Blood pressure spikes, able to account for all of the above problems, and also unconciousness, strokes, internal bleeding, subcutaneous hemorrhaging etc, would be trivially explained by slight differences in travel leading to localized compression of tissues. The differnces would need to be slight, and not have a hard onset, otherwise the tissue would not be deformed but ripped.
Elastic tissues would then quickly bounce back, producing the pressure spikes - inelastic tissues, like teeth or highly calcified bones, would retain the slight deformation (possibly even a way to prove the time-travel)

When you travel and re-integrate back in time, you are actually going to occupy a volume of space that's already filled with air.

Even if air is not very dense at all, the effect is the same as if some molecules at random in your body were disrupted by hitting them with either an oxygen or a nitrogen molecule, hard. The net effect would be very much like that of a haemorragic fever.

A "time travel machine" would then be just a vacuum chamber where your pressurized time capsule could safely reintegrate.

But in absence of a machine at the receiving end (and this always happens the first time a new temporal beachhead is established), even when avoiding this as much as possible by time-traveling in parachute gear and oxygen mask and re-materializing at 30,000 feet, time travel is going to hurt. Anywhere below 30,000 feet, it's probably going to be lethal.

A different possibility is that time travel, due to quantum handwaving correlation, does a number on radioactive isotopes (actually, time travel might have been discovered as a byproduct of research into artificial radioactivity - turning unstable isotopes into stable ones without waiting for the required thousands or tens of thousands of years). The sudden release of ⁴⁰K (and other isotopes') potential radioactivity in a body would cause a (mild?) bout of radiation sickness; its lethality could be tuned to one's heart's content.

Time travel could alter your body's schedule. Ripping a hole in time and going through it can't be normal for a body that travels only one way through time. Consider having your heart unable to properly time its contractions could cause a racing heartbeat or one that lethargically pumps blood every two or three seconds. Or the right half of your brain works twice as fast as your left side. Or the nerves in your lower half move at a crawl.

Or it could be that for a short time your body isn't all in the same time. Having your muscles grow for three weeks, while the rest of your body only has a minute pass can't be good. Having your brain 5 minutes ahead of your nervous system will not be good for your mental stability. This could cause a minor seizure or wounds, or it could cause insanity and death.

Air composition and Diseases your body isn't ready for.

The latter one is easy: there might be Illnesses your body has NO experience with, which would therefore hit the time traveler really really hard (also he might kill everyone where he appears, see what happened to the Incas when Spaniards arrived)

The first thing I don't know whether it would be significant, but for traveling like 100.00 years or so it probably will be.
For example the Oxygen content in the air is constantly changing and could leave the time traveler heavily breathing or even passing out upon arrival from a lack of oxygen or going hyperactive and stuff from an oversupply.
[Which would certainly be a positive feat]

Also Air pressure might screw with the Body, but I think that wouldn't be too critical apart from dizyness the first couple of minutes.

The G-Force equivalent in Time dimension can be used here.

Since, while travelling in three spatial dimensions, one chooses the acceleration in tolerable limits. And there would be trade-off with the travel-time vs the comfort-level.

Similarly, during time travel too, one can expect an equivalent force. Which could limit his number of travels, speed of travel(if not instantaneous), duration in time traveled.

Assuming a time travel in which the factor of time is altered in a contained area:

Irregularities in the pace of time all across the body. Imagine that while the person is moving with the factor of -10000 of the regular speed of time (which would be 1), the effects may not be constant across his entire body.

Simply said: The heart may occasionally pump half as fast, blood may stuck at some places, the electrons sent throughout the body may suffer weird delays, breathing may become an issue, all along with uncountable body functions which would be disrupted. And all of that also with the opposite effect of being quickened.

Imagine the effects like the surface of an unruly ocean - and map it to a body. It may have a certain sea level, but it has slight variance all around that.

Now assume that these factors are not too radical, however they affect the entire body in varying and shifting magnitudes in both directions (quickened and slowed), all of which add up to discomfort, pain, injury or even death. This may also put restrictions to the possible time distance which can be travelled, as it has to be evaluated based on endurance, training, time factor and time distance - meaning some people may withstand more, possibly even have a higher natural tolerance (as a plot device). The energy or resource requirement may affect the time factor (thus being less or more harmful).

A resourceful villain may have little to no issues travelling the same distance than a protagonist lacking said resources. This could invoke great demands on the protagonist which can however be overcome.

By the way, I think this last also implies that the spatial precision of the time travel has to be even higher than 1 part in a thousand trillions.

[I got this one from a story in a recent issue of Analog magazine : ]

When you time-travel, all of the particles in your body are removed from the universe upon your departure and reappear upon your arrival. If you travel forward in time, the net of it is those particles simply cease to exist for a period. That's fine. But if you travel backward in time, you arrive in a universe where all of the particles in your body already exist, scattered around the planet. From a quantum-mechanical perspective, each of your particles now has a bimodal wave-function - i.e each particle's 'location envelope' [re: uncertainty principle] has two peaks, one in your body and one somewhere else.

This is NOT a stable situation. Much like radioactive decay, over some period of time the wave-functions of all your particles must collapse back to a single peak! And there is no reason why they would collapse back to one peak versus the other. Net result: Immediately upon arrival, particles in your body (in effect) start disappearing at random - leaving behind broken fragments of protein and/or DNA, missing bone mass, free-radicals, and other nastiness. A painful death is sure to follow, unless you return to your own time almost immediately upon arrival.

For a time I've been pondering with the idea of atoms in time. As we know time naturally move only forward. And atoms are the foundation of universe. They are the same as they we're billions and billions years ago. But they change. They form new materials, new elements.

So for example Carbon-14. You take 100 year old spoon and travel with it to the day it was forged. It contain the same atoms minus the one lost during those 100 years. But what with the missing ones? They've been lost along the spoon life but now they are present in the "source", but have two same "matrixes" they should belong to, in that particular place in time.

The "missing" atoms try to fill equally both items. So the first one is suddenly aged by half the time the second item is older while the atoms move to second one. The pain to you is that you are suddenly filled with extra atoms. The pain increase with time you travelled as the amount of atoms trying to fit in increase but your cells are not the ones that should take them. You know the story about how every few months your blood is new, your skin changes and after 7 years you are a new man. So you experience pain of growing bones, muscles, hormones present in kids bodies.
I came up with two solutions:

It isn't the travelling through time itself that does the damage, it's the method you're using.

The early-tech approach your protagonists use to hurtle through time is more akin to pulling on a parachute and hopping in a trebuchet to travel, rather than a nice smooth car ride. Even if you don't hit something or miss the target, you get exposed to a lot of Gs at the start, middle, and end as you accelerate/decelerate.

Subsequent refinements will lead to a smoother start/finish to the travel, and even later you might get the equivalent of suspension to make the journey more comfortable.

(Also, time lag: It was 6pm when you left, it's now 8am. Some people are groggy for days just crossing continents...)

Time travel involves the traversal of a portal. Anything passing the surface (let's call it "event horizon") of the portal is "instantly" transported to the target coordinates. Now, imagine stepping slowly into the portal and then stopping. One half of you is in the past, the other is still here.

I think you can imagine the rather messy result (on both ends).

To travel in one living piece, you have to hurl yourself in a free-fall trajectory through the portal, so everything reassembles nicely on the other side. But there will still be inaccuracies, which lead to a (author-tuneable) multitude of micro-haemorrhages.

The interruption of brain function could also cause loss of consciousness, if so desired.

An important thing to consider is that for interesting modes of time travel (i.e. you apparently stay in the same place) this also involves traveling through space and adjusting your momentum and angular momentum in space as well. For instance, depending on latitude, if you move just a second back in time, the Earth will have rotated approximately 450 meters away from your starting point while in that same second the Earth also has moved 30 km in its orbit around the Sun (and the Sun around the galaxy center and so on).

Now all this momentum and angular momentum adjusting takes a lot of energy and usually the energy input is not always completely turned into useful work (=displacement in time and space and adjustment of momentum and angular momentum), but some of it is turned into heat. If some of that heat is absorbed by the body of the time traveler then the time travelers temperature will rise with interesting biological effects, if the temperature rises above 42 degrees Celsius then permanent brain damage will result (this is one of the first body subsystems to fail).

Now, time travel in itself requires a lot of handwaving of the laws of physics so let's hypothesize a mode of time travel wherein one would 'jump' through some hyperspace (or flit between branes) from one point in space-time to another. The step can be large or small and the only energy required is that needed to jump to the other brane and then step back from it on this brane. Other answers postulate the instantaneous time travel mode, but I favor the semi-continuous mode, a lot of consecutive tiny steps each of the order of the Planck length (~ 1e-35 meter) and/or Planck time (~ 1e-43 s) but in a different direction then the light cone of this universe. This mode provides the time traveler with ample opportunity to thwart invasion of strange molecules, adjust momentum and angular momentum and to dissipate excess heat during the jumping, perhaps to the other brane.

If time travel is based on a field of effect (rather than a portal-type event horizon), then each atom in the traveler's body materializes rather abruptly on the other end.

While the scientists have accounted for variations of ground height and surface composition between origin and destination (travelers begin the transition on an appropriately tall platform, which does not make the transition with them, resulting in a small fall upon arrival), they cannot account for variations in matter above ground.

Expected levels of atmosphere at the destination are filtered out by the process, but extreme variations in water content (fog, rain, snow, etc.) cannot be fully filtered. For the most part, the body tolerates this fairly well. Some parts of the body don't tolerate this well, though. Suddenly having your stomach filled with rain or snow can induce some significant nausea, or even vomiting. Lungs suddenly filled with moisture will, at the very least, lead to violent coughing fits. If enough water gets in the lungs (e.g. a heavy rain/snow fall)... as little as six tablespoons for a child... something known as secondary or dry drowning can occur.

“They may emerge from the water coughing, vomiting or seeming to have no obvious or distressing symptoms right away. Some hours or days (sometimes up to 48-72 hours) later, the patient may exhibit one or more of the following signs and symptoms:

• Changes in behaviour

• Fatigue

• Lethargy

• Coughing

• Shortness of breath

• Pale skin

“It is dependent on the type of water (salt, fresh, chlorinated) and
amount of water inhaled as to how severe this condition can be,” Heidi
explains.

“The damage that water can do to the sensitive airways in the lungs
can be significant and life-threatening. In all cases, it should be
treated as a medical emergency if any of the above signs and symptoms
are observed. After every submersion where the patient is having any
kind of difficulty breathing, they should always be observed in
hospital,” she says.

Moisture suddenly being added to the body isn't the only risk.

Our air is rarely empty. Insects, pollen, vegetation debris (seeds, leaves, etc.), or even pollution (assuming humans are present in the target time period) can occupy a human-sized space of air.

These contaminants suddenly appearing within our muscle mass would certainly hurt for quite a while, until cysts can form around the invading material. But if a dragonfly is suddenly embedded in your kidney, or a leaf suddenly bisects your intestines, you're going to have some pretty significant problems, possibly including bleeding from an orifice.

In a causality case where travelling back in time changes the events of the future, you could have some side effects like the ones shown in The Butterfly Effect. Every time Evan travels back to the present (after a little trip to the past) his memories sync with whatever he changed in the past. Overtime, this causes him to have massive seizures and strokes that might, ultimately, end up frying his brain. This option works perfectly if your ideal downside you're looking for has to do with neurological problems.

If you get the case of the travelling twins, you could apply severe dizziness, multiple orifice bleedings (probably organ failure as well), concussions and all kinds of physical damaging to organs, since the human body is definitely not ready for near-light-speed travelling.

If you're up for something that requires the "because I want it to be that way" explanation, you could use the parallel universes case. Just say that the parallel universe to which the subject travelled has a "different atmosphere" or some bullshit excuse like that - just say that something is not the same. This subtlety (higher gravity, some new element in the periodic tabe, another gas in the mix of atmosphere... there are literally infinite options here) makes the traveller get sicker and sicker until he leaves this universe and comes back to his own.

You could use radiation poisoning that leaks from the machine. There are several kinds of radiation you can look up online or you can also create your own - but in general, radiation poisoning has some real nasty effects that cripple a person overtime and are not detectable for some time. This would be an excuse as to why "he didn't know it was harmful".

A paradox is also a good explanation for some psychological-rooted side-effects. Let's say the subject meets his parents before he was born, or even himself. The shock of that meeting might spark neurological problemas like split personalities or schizophrenia. Also, there's other kinds of shock that could be related to the contact with something unconceivable by the subject, like the very travelling itself or getting in contact with a future version of society - something unconceivable to him.

All in all, I don't think there is a correct side-effect, even more so since you are not really interested in a specific type of time-travelling, you just want an answer that's good enough for you.

My answer would be any answer. Maybe time-travelling has different effects in different people. You might feel dizzy and bleed from your nose while I could get a frequent panic attacaks for the rest of my life.

Just look up for nasty symptoms from wired diceases and you will have a lot of ammo for your thoughts.

Actual Radiation Sickness.

Exotic forms of matter and energy are a given factor in most reasonably hard-science interpretations of time-travel, the hard Rads given off by say..bending space-time into a knot are probably lethal in and of themselves.

You might be able to shield against the worst and medicate against the rest, but you'd better hope you travelled to the future to find a Cure for Cancer first!

Your time-traveller is medicating constantly with anti-radiation drugs and Cancer-therapies to stave off a messy and painful death.

More advanced time machinery and techniques meanwhile would shield the user against it much more effectively and produce less deleterious effects in the first place, but your early-model time-capsule is more or less a cancer-box.

Better aim for somewhere unpopulated.