One interesting fact that most time traviling stories ignore

[Darzin]

You wouldn't die from eating medieval food, I've been to remote mountian villages with not electricity no running water and nary a health inspector in sight and i'm still alive you might have some gastric distress or not depending on freshness but you'll get used to it sooner or later the same as the locals do. 

[HoodedCrow]

You might die from the water. I thought medieval food was mostly about having a cooking pot and boiling whatever is in it.( meat, veggies, herbs)and beer( alcohol kills the germs).

[Larry of the Lawn]

2 hours ago, HoodedCrow said:

You might die from the water. I thought medieval food was mostly about having a cooking pot and boiling whatever is in it.( meat, veggies, herbs)and beer( alcohol kills the germs).

I think it's less the alcohol killing the germs (beer is probably lie enough abv that bacteria could thrive in it) and more that in the process of making it the water is boiled and thus sterilized.

[Filippa Eilhart]

I feel like a lot of these points were addressed by Connie Willis.

[Wilbur]

For me, the time-traveler issue is less "what will eating and drinking in the target time do to the traveler", and much more of "what happens when the volume of space in the target time is displaced by a suddenly-appearing traveler".

Shouldn't two sets of matter immediately trying to occupy the exact same space at the exact same time cause some sort of cataclysmic nuclear fusion?  That has always been the nagging thought for me.

[Fragile Bird]

Oooh, I can time travel, I’ve had the smallpox vaccine!

[Larry of the Lawn]

3 hours ago, Wilbur said:

For me, the time-traveler issue is less "what will eating and drinking in the target time do to the traveler", and much more of "what happens when the volume of space in the target time is displaced by a suddenly-appearing traveler".

Shouldn't two sets of matter immediately trying to occupy the exact same space at the exact same time cause some sort of cataclysmic nuclear fusion?  That has always been the nagging thought for me.

Yeah, tangentially, and I am admittedly a total ignoramus when it comes to physics, but wouldn't this break the law of conservation of matter?  Or when time travelling would all the molecules in my body be reassembled from their past locations- ie instantaneously jerked from their locations in say the 1066 world and thrown together to create 1066 Larry?

 

[Wilbur]

15 minutes ago, larrytheimp said:

"...1066 Larry..."

 

Ooh, a cool new username!

[williamjm]

1 hour ago, 1066 Larry said:

Yeah, tangentially, and I am admittedly a total ignoramus when it comes to physics, but wouldn't this break the law of conservation of matter?  Or when time travelling would all the molecules in my body be reassembled from their past locations- ie instantaneously jerked from their locations in say the 1066 world and thrown together to create 1066 Larry?

I guess it depends on how the travel works but maybe one option could be to move an equivalent amount of matter forward in time to the amount being sent back in time.

[Kalbear]

I think y'all are conflating time travel with teleportation. 

As a thought experiment - you don't think about how you're displacing air as you walk, right? But that's effectively traveling in time as well. A lot depends on how you get to the place you're going in time. If you're traveling like the Time Machine - where everything ages around you in the same place and time - then there's nothing to displace. If you're doing it Terminator style, where you have some glowing orb of death - that's a bit more problematic, and from the look of it everything in that sphere is annihilated in some interesting violation of local physics.

[A Horse Named Stranger]

On 10/8/2021 at 8:18 PM, Wilbur said:

For example, my background is such that dairy products and "high" game meats are on the menu frequently.  However, I can't host most visitors from Asia to meals with either dairy or game meats unless I want to lose them for about 24 hours of suffering with the Gods of Angry Bowels.

Lactose intolereance is not evenly distributed among ethnicities. So you have a much higher chance of your Asian visitors not being able to process dairy products. You can look it up. Prevalence is 90%+ or so in that group for lactose intolerance.

Drinking milk is really one those Northern European diet habits. Culturally, colder climates (esp. in the winters) has made milk a very appealing diet option (fat and all). There the prevalance is 20-25% or something like that.

[Leofric]

28 minutes ago, Kaligator said:

I think y'all are conflating time travel with teleportation. 

As a thought experiment - you don't think about how you're displacing air as you walk, right? But that's effectively traveling in time as well. A lot depends on how you get to the place you're going in time. If you're traveling like the Time Machine - where everything ages around you in the same place and time - then there's nothing to displace. If you're doing it Terminator style, where you have some glowing orb of death - that's a bit more problematic, and from the look of it everything in that sphere is annihilated in some interesting violation of local physics.

Walking and the Time Machine are not adding additional volume and mass to the world, they just readjusting its location as you move (or things move around you in the Time Machine's case).

The terminator sphere is forcing its way into the new timestream and expanding rapidly, compressing the air and solids around it that are being displaced, causing friction, heat, and static discharge.  So the surrounding atmosphere will be slightly denser after the time traveler arrives as the volume and mass of the traveler's body and the air he brought with him in the sphere are incorporated into the timestream's atmosphere..  

[Winterfell is Burning]

It's my professional opinion that if you can create a way to travel back in time, but are too dumb to not eat anything you're not sure it's clean enough, the universe is better off without you.

[Larry of the Lawn]

Guy who travels back in time 20 minutes to eat the steak he just ate fully cooked, but this time eats it raw.

Going back in time to drink raw milk.

[Buckwheat]

On 10/12/2021 at 3:35 AM, 1066 Larry said:

Guy who travels back in time 20 minutes to eat the steak he just ate fully cooked, but this time eats it raw.

Going back in time to drink raw milk.

But then there won't be any steak left for him to eat it in the future cooked. Sooooo, did he really eat it cooked in the future? Another time-travelling loop. This time with steak!

[Wilbur]

OK, so let's say that the paleobiologists have figured out the food and nutrition issue, and the physicists have figured out the not-causing-a-nuclear-conflagration issue, where do you aim your time machine?

By that I mean that the starting location in space of the origination point in time is going to be millions or billions of miles from the target location in space, right?  The Earth is orbiting Sol, Sol is traveling through the galaxy, which in turn is hurtling around in the universe, etc. etc.

So calculating where the exit point for the time machine should be will present a task of immense proportions, and if you get it wrong, the time traveler will likely not have to worry about food or matter/anti-matter annihilation, as he or she will just show up in an empty volume of space and proceed to choke to death in the vacuum.

[Prue]

On 10/12/2021 at 1:22 AM, A Horse Named Stranger said:

Lactose intolereance is not evenly distributed among ethnicities. So you have a much higher chance of your Asian visitors not being able to process dairy products. You can look it up. Prevalence is 90%+ or so in that group for lactose intolerance.

Drinking milk is really one those Northern European diet habits. Culturally, colder climates (esp. in the winters) has made milk a very appealing diet option (fat and all). There the prevalance is 20-25% or something like that.

Actually, being lactose INtolerant is normal for most people world-wide. Being lactose *tolerant* is a fairly new mutant that only evolved in Europe around 5,000 years ago and managed to spread because it was an advantage to get nutrients from drinking cow milk as an adult, in the harsh winters. I saw a documentary once where they said that DNA analysis of over-5,000-year-old remains in Europe showed that none of the old Europeans were lactose-tolerant yet either, whereas the percentage suddenly increased afterwards. 

eta: Apparently it was about 7,500, not 5,000 years ago. Sorry.

https://www.uni-mainz.de/presse/15305_ENG_HTML.php

https://www.uni-mainz.de/presse/aktuell/12031_ENG_HTML.php

[Larry of the Lawn]

7 hours ago, Wilbur said:

OK, so let's say that the paleobiologists have figured out the food and nutrition issue, and the physicists have figured out the not-causing-a-nuclear-conflagration issue, where do you aim your time machine?

By that I mean that the starting location in space of the origination point in time is going to be millions or billions of miles from the target location in space, right?  The Earth is orbiting Sol, Sol is traveling through the galaxy, which in turn is hurtling around in the universe, etc. etc.

So calculating where the exit point for the time machine should be will present a task of immense proportions, and if you get it wrong, the time traveler will likely not have to worry about food or matter/anti-matter annihilation, as he or she will just show up in an empty volume of space and proceed to choke to death in the vacuum.

I don't know if you'd need to know this (the specific locale in xyz space) there could just be default settings.  Basically what Kal said earlier -- the Time Machine model would render this irrelevant as it would swing around a subject in a relative locality.  Even if the planet or solar system had caterwauled light years through space the relative position (of the time traveller could remain the same (although typing it all out on not sure why we should assume that, actually) would be constant, bit yeah if the atmosphere became unbreathable, or there was so much radiation that your skin would become a melanoma garden, shit.  Fuck, man .

[Soylent Brown]

On 10/12/2021 at 2:35 AM, 1066 Larry said:

Guy who travels back in time 20 minutes to eat the steak he just ate fully cooked, but this time eats it raw.

Going back in time to drink raw milk.

If you really want to do things properly, the rawest milk is grass.

[Wilbur]

Two authors who handled time travel to my liking included Walter Jon Williams in his noir Days of Atonement and Vernor Vinge's Across Realtime.  I am a bit biased, as both stories include scenes in specific, real-life labs or R&D centers that I am personally familiar with, but in both, the issue of time travel has a currently-valid scientific rationale for how it works.

Vinge uses a stasis field to travel forward in time without aging, while Williams goes with field entanglement.  Reading either story gives a plausible reason why food, location in space, medicine, etc. aren't an issue for the time traveler.