Suppose in this modern era we have the technology and means to time travel a couple millions of years into the past with a return trip less baggage of course! The science community owns the tech and doesn't want to abuse it or disturb the past too much afraid it may have any catastrophic ramifications and alter all reality where human beings ceased to exist.

Long story short we will have a small team of 5 trained explorers who will be visiting the Neanderthal and observe their demise by the early humans or wild cat, how can they hide their presence while filming the documentary and suppose they need to establish an encampment nearby for R&R and charging up their equipments etc?

No worry in the event should the safety override is compromised the system only allows going back 50 millions of years into the past in case someone had incorrectly dated the extinction event and no UAV allowed. Definitely no strapping GoPro to other wild animals even though you may think they are your distant relative, please focus on the safety of filming crew for now. No disguising as Neanderthal or any animal and that's including trees. Last but not least leave no man or traces behind, do not alter the food chain and yes hoverboard is the other breakthrough beside the time travel how cool is that!

Destination is Siberian Cave 50,000 years ago and duration of stay is 2 years.

  • 1
    $\begingroup$ It depends on the model of time travel. Care to clarify that up front? $\endgroup$
    – JDługosz
    Aug 29, 2016 at 7:30
  • $\begingroup$ It's worth keeping in mind that any creatures capable of surviving in the environment of that day are likely to be highly attuned to their surroundings. They might not realize what's going on, but I suspect they would notice anything that is somehow out of the ordinary, simply because noticing, say, the predator lurking in the shadows, would be a critical survival skill. $\endgroup$
    – user
    Aug 29, 2016 at 7:32
  • $\begingroup$ @JDługosz Sounds to me like OP has single-timeline go-back-and-forth everything-interconnected time travel in mind; supported especially by the mention of disturbing the future by disturbing the past as described in the first paragraph. What further clarification did you have in mind? $\endgroup$
    – user
    Aug 29, 2016 at 7:34
  • $\begingroup$ The fact that travel is allowed at all means that we don't expect chaotic changes years down the road from an arbirary small change initally. So are peturbations self correcting to keep on the same track? Or are they creating different timelines with every step but the return portal connects back to the original? $\endgroup$
    – JDługosz
    Aug 29, 2016 at 7:44
  • 1
    $\begingroup$ What do you mean by "a return trip less baggage of course!"? $\endgroup$ Aug 29, 2016 at 17:35

5 Answers 5


Okay, you mention a documentary, by which I’m assuming you want to make the Neanderthal equivalent of Human Planet or a David Attenborough wildlife film. If you actually meant something different, ignore this answer.

Your documentary will be a bit dull. Scientists and TV producers want different things from footage. 3 hours of the Neanderthals lying about belching, scratching and picking their noses is useful to scientists, since it tells them something about Neanderthal daily activity cycles, metabolic needs, and so on. But for television, it is deadly dull. TV wants ‘interesting’ behaviours.

Documentaries featuring humans involves getting the folk featured in them to sign Contributor Consent Forms and agree to have the camera crew following them about, living in their pocket. Without consent it is more like the paparazzi harassing celebrities. Yet even then the celebs tend to know the paparazzi are there. Your set up is way more difficult than that – the camera crew has to effectively be invisible.

Wildlife documentaries very often feature habituated animals. The animals (usually because scientists have been studying them for years) are accustomed to the presence of humans and/or vehicles. They go about their daily business, ignoring the cameraman. If the animals are too twitchy for human proximity, you habituate them to a hide. Then the cameraman films from inside the hide. Again, you have crossed these two options off your list.

Camera traps. Most animals are, quite frankly, a bit thick. If they notice a camera trap they’ll maybe sniff it, lick it or paw at it, but it is an unthreatening, inanimate object so they’ll quickly lose interest. To them it is just an odd shaped rock. However, humans (including Neanderthals) are smart. They might classify it as ‘rock’ but they’ll be well aware it is like no rock they’ve ever seen before. They’ll spend a lot of time and effort trying to work out what it is, where it came from, etc. And because it is weird, it may get classed as ‘dangerous’ even if it is just sitting there doing nothing. After all, evil spirits might have left it there…

So your cameras have to be hidden, but not disguised as anything. The only solution I can see is to put them far away from the action. Halfway up a cliff. High up in a tree (scarce on the tundra-steppe). On a hill on the opposite side of the valley. Your cameraman will be doing a lot of long lens work. You won’t be able to get the variety of shot sizes that you are used to seeing in a wildlife documentary (no close ups, for instance).

Microphones. Compared to cameras, microphones have a very limited range. Your cameraman can sit on a distant hillside, filming everything on a long lens, but your sound guy can’t. The sound guy needs to get really close – ideally within 10 or 20 metres. As a result, a hell of a lot of wildlife is filmed mute, and the soundtrack is recreated later in the dubbing suite from recordings of animals taken elsewhere.

This is the best I can come up with for safety and minimising contact:

  1. Send a ‘scouting’ expedition through to somewhere you know has no Neanderthals. An island they never colonised. On a glacier. Up a mountain. Somewhere way out on the permanent sea ice. The harshest bit of the tundra, further north than Neanderthals could cope with. Set up Base Camp 1 there. (My personal favourite is sea ice, as all you’ll encounter is the occasional polar bear or arctic fox, so no chance of spreading disease or being attacked by sabretooths. Take flashbangs and stink bombs to scare off any polar bears).
  2. Launch UAVs to find out where the Neanderthals actually are. I know you banned these, but I can’t figure out how you can work out where your explorers need to go/avoid without some sort of high altitude aerial recon UNLESS they want to risk being seen and/or encountering something dangerous.
  3. Spend a year mapping out where the Neanderthals go. As this year progresses, you’ll start to discover places they inhabit periodically. For instance, they spend the spring in a cave by a river and the summer out on the steppe. Or they visit the lake about once a week. As you map these, you can start to hoverboard your explorers into these places to plant hidden cameras, when the Neanderthals aren’t around. You may also need to have a series of hidden relays to transmit the signal all the way back to Base Camp 1.
  4. If possible, identify a more suitable (hospitable) site for Base Camp 2. Closer to your cameras, so less of an effort to swap out batteries, clean lenses, fewer relays needed, etc.
  • $\begingroup$ +1 but I must ban drones. $\endgroup$
    – user6760
    Aug 30, 2016 at 12:10

Time travel via astral projection.

The voyagers are using psychic phenomena in order to travel in time. Their bodies would be connected into a machine that records brain activity during the jump. If there is no brain activity during the astral projection experience, then after the jump use regressive hypnosis with a different machine that decodes the signals of the visual cortex and reconstructs the feed as live video; cross check against all the voyagers for accuracy. (Two of these sorts of machines are actually currently in development.)

As long as the scientist using astral projection doesn't cohabit (share the body with) any long-ago individual: no residue, no trace, no influence.

Unless, of course, you run afoul of the quantum effect and the act of observation does in fact change the observed.


The mind is a largely untapped and ill understood resource. Whether the mind is tapping into a collective quantum consciousness of humanity to find the information, or to channel effects through a particular person, there are many possibilities for a futuristic method of psychic time travel.

  • Psychometry is sensing the past.
  • Astral projection is the spirit leaving the body, and travelling (and witnessing) to locations and events far away.
  • Clairvoyance is seeing something far away. (Other senses have specific names attached to them, for example Clairaudience is for hearing things far away).
  • Teleportation is jumping from one point to another in spacetime without traversing the distance in between.

Combine these four psychic effects, perhaps boosted by some tech, and you have effective time travel into the past. It's probably easier to send a spirit than a body and equipment as less energy would theoretically be required.

  • $\begingroup$ I'm not sure how yr clairvoyance works but we r talking about the 21st century C.E. can u rework on ur interesting yet farfetched answer thanks. $\endgroup$
    – user6760
    Aug 29, 2016 at 17:54
  • $\begingroup$ Clairvoyance is not the same as astral projection. I'll see what I can do. $\endgroup$
    – nijineko
    Aug 30, 2016 at 3:44
  • $\begingroup$ @user6760 - I've made some changes, hope that helps. $\endgroup$
    – nijineko
    Aug 30, 2016 at 17:44

Ever heard of the butterfly effect?

The most simple presence may change anything around. A single air pressure perturbation may result in an insect changing its trajectory therefore mating with a different insect therefore its siblings would have a slightly different behavior, changing slightly who they sting, changing slightly when people have sex ("kill that mosquito first dear"), changing slightly what spermatozoon would be selected, changing a lot history 10000 years later, making the scientists who went to the past to never have been born in the first place.

This has a low chance of happening from a single presence for a few seconds. However, if you want your scientists to stay for years and you don't have access non-material projection, you're doomed to fail.

You need a big fat telescope

Go 50000 light-years away today with your big fat telescope and point it at earth. Record, travel back.

Yes, this is not very efficient, but (until you give us exactly what type of time travel you want) this is the only way to avoid our total doom.

This answer is supported by the Consortium Against Time-traveling to the Past (CAT->P).


Required supplies:

  • 8 gallons of tiger urine

  • 30 kgs of sun-dried meat

  • 30 kgs of dried vegetables

  • 5 tranquilizer guns (1 for each member) with 300 tranquilizer darts.

  • 5 high magnification, night-vision binoculars (1 for each member)

  • High tech video capture cameras. Shock proof, water proof, and with at least 60x optical zoom, capable of working in low-light conditions.

  • Voice communication devices. 1 for each member.

  • 4 gallons of kerosene oil and 15 electric lighters (which heat up a filament with electric current, without using any fuel or spark)

  • Solar chargers for all electric/electronic devices mentioned above.

  • 2 sets of camping equipment. This includes sturdy tents, ropes, sleeping bags and cooking equipment.

  • Condensation equipment to capture water vapor in the air and condense it into liquid form.

  • Fishing equipment


Set your time travel device so that it stops at late evening time.

Quickly exit the device and set up a camp. Try to choose a location which is around 200 meters from the woods and at least 500 meters from any river, stream or lake.

Sprinkle about 1 liter of tiger urine around the camp site. This will help keep predators away and set up a security perimeter around the camp.

In the night, examine the region with the night vision binoculars and locate a secluded cave for a permanent abode. Make sure that the cave is not home to humans or neanderthals.

Move over to the cave on the evening of the next day. Root out any predatory animals living inside by sprinkling the door heavily with tiger urine. This will send the predator inside rushing out, either in a mood of challenge or a mood of flight. In case the predator is aggressive, take it out with a tranquilizer shot and relocate it far away from the cave.

Stay in the cave for the next 2 years, filming from as far as you can. Don't get out in daytime. Try and fish for food, without killing any prey animal. Also utilize any fruits growing in the region.

In case of encounter with a neanderthal or predatory animal, use the tranquilizer darts to take it out and make sure to relocate it/him to a different site so that it wakes up with a confused mind and does not feel certain about the events after it got tranquilized. One person should always be sitting on the lookout, at the cave entrance. At night, always block the entrance with a heavy rock.

  • $\begingroup$ So, no pressurised suits? How are you going to protect the Past from infections you have on (and in) your body, which they wouldn't be able to deal with? And how exactly are you going to get rid of all wastes (a few centuries later someone might find your futuristic garbage)? Not to mention local legend about "cave nobody can go in" that might have a lot of unforseen concequeces. $\endgroup$ Aug 29, 2016 at 9:57
  • $\begingroup$ I commend you on the usage of predator urine as repellent and make sure to sterilize it to prevent introducing new bio hazard into the environment, please focus on stealth and keep a low profile and kidnapping the Neanderthal or other wildlife is strictly prohibited even on spur of the moment with tranqs. $\endgroup$
    – user6760
    Aug 29, 2016 at 10:07
  • $\begingroup$ @MrScapegrace: what futuristic garbage? And they would already be a lot of caves nobody could go in. Caves which are home to smilodons, homotheriums and the dreaded short faced bear. Trust me, these are all examples of caves nobody can go in. Your cave won't be any peculiarity. $\endgroup$ Aug 29, 2016 at 10:27
  • $\begingroup$ @YoustayIgo Would the tiger urine even work well? Those saber toothed tigers are gonna get really angry over something marking their territory, and if they find those (un)fortunate time travelers at the right(wrong) time... $\endgroup$
    – Skye
    Aug 29, 2016 at 13:23

I can only see a safe means by preventing anything from screwing up the timeline to be a journey to the past and in space

so basically put the time machine in orbit and travel back with a space station like the USSR. bring materials to build satellite telescope and that's the safest I would think.

That is of course u make sure u pack up everything when u go back.

In terms of a landing party I would think you'd need to accept some changes to the future; like as soon as u land u start growing hair in your palms as evolution has now changed.

other than space maybe the rule about packing up is not necessary as the time machine auto brings back all that it brought with it such as the foot one of your men lost to an animal (including the nutrients it gained from digesting it)

then u could go underground and use periscopes and x-rays to get footage

although moving footage will be a problem for x-rays (would be blurry)

could use the x-ray to make sure nothing with a skeleton is around before pushing the periscope through


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .