Interstellar Navigation

[@winfehler]

„Do you know where we are ?“ „No, but I know _exactly_ how fast we are going !“

[@seriousmaran9414]

You only know how fast you are going relative to something else.

[@markoconnor1691]

@@seriousmaran9414 It's a Quantum Mechanics Measurement joke.

[@brine_909]

@@seriousmaran9414 A) it's a quantum mechanics joke B)where you are is also only relitive to something else aswell

[@muninrob]

I figured out where we are - but I broke the speedometer

[@seriousmaran9414]

@@muninrob obviously using too many hamsters in the wheel :)

[@R_C420]

_"Clark, isn't that the same nebula we passed five light-years ago?"_ _just thought the kids should see the plight of the inner Galaxy, honey_

[@justinyoung5290]

Pardon my use of your comment as a sandbox _but I want to see if this is the secret to italics_

[@justinyoung5290]

Well that's not it...

[@ribhuhooja3137]

@@justinyoung5290 Remove the full stop at the end or add a space between it and the underscore _like this_ .

[@justinyoung5290]

@@ribhuhooja3137 Thank you! I hope you enjoy the rest of your day.

[@taufiqutomo]

_let me try using two underscores in the hope of achieving the intended italics format_ -we'll try strikethrough with two dashes- please do not use strikethroughs!

[@RCAvhstape]

How to navigate through interstellar space: The Spice. Lots of it.

[@seanthompson9163]

Holtzman's equations can be trusted, even if we don't understand how or why they work...

[@brandonchapman4922]

That's funny. Where I come from we call DMT the spice

[@masonman_2113]

To bad Muad Dib is destroying spice production

[@seanthompson9163]

@@masonman_2113 He is teaching them a lesson their bones will remember

[@TheBakedalaskajoe]

I was thinking how terrifically this explained why the guild requires navigators.

[@DavidEvans_dle]

- ”That navigation beacon only has http not https?” - -”I don't care, just follow it!" - ”Its a Nigerian system overlord, he's says welcome to his solar system. And he has a proposition for us...'”

[@aurex8937]

Oh yes, this is the perfect moment for your upload. Tea's ready, crumpets are in sensor range and I was already on a re-entry trajectory towards my chair. Thanks Isaac!

[@hobbermc]

I’m sure that this comment will get buried but I’m not on any other social media so, on the off chance Isaac sees this: I just wanted to thank you for all these years of awesome videos. I think I’ve been watching since the 3 or 4 episode and as an avid sci fi reader (particularly Alastair Reynolds) this has been one of the best documentary series I have ever seen after Cosmos. So, thank you Isaac for all your hard work and Happy Christmas. Also, on the off chance you see this I would like to recommend Sister Alice by Robert Reed. May not be very scientifically accurate but definitely captures the “any significantly advanced technology is indistinguishable from magic” theme.

[@Splaccemttv]

Gleeeeeee

[@AtomicFrontier]

Normally I listen to these as a podcast, but your visuals have gotten so great I'm glad the holidays have given me the time to watch them properly. Thanks for another awesome episode!

[@kylekissack4633]

Agreed 👍

[@michaeltan7625]

Well the Emperor's light guides of course!

[@ufuker5754]

And inbred navigators

[@ufuker5754]

@Mikhail G well no 40k as astetic and theme is awsome but as locistic and reason it is retarted i does not make sanse but in real world does not make sense like oil endisty

[@captainpuffinpuffinson4769]

In the name of the emperor we shall conquer the galaxy for all mankind

[@trentonarney6066]

I was looking for this comment.

[@ryanhawe8234]

"Let's not go to Exegol. It's a silly place."

[@littlegravitas9898]

I've a well charted path, to navigate my way to the fridge, so I can collect compulsory snack and drink. Then it's just time to settle in and go interstellar!

[@Zarcondeegrissom]

well-plotted course for many that have the same result, yet so different in the plotted path to that result. lol.

[@seriousmaran9414]

*fridge drops out of universe taking contents with it.*

[@powerwolf-vw8st]

Travelling through hyperspace ain't like dusting crops boy - Han solo

[@icecold9511]

Apparently it is, when Poe was skip jumping all over hell in movie 9, even into atmospheres and cities

[@johnboettcher1962]

What is crop dusting for moisture farmers?

[@RT710.]

@@johnboettcher1962 lol a slight breeze?

[@larrybeckham6652]

The one I like when See-Threepio says, "Sir! The odds of successfully negotiating an asteroid field are 0.9999999999 to 1!"

[@dirkstarbuck6126]

@@icecold9511 That’s why Disney SW is just expensive fan fiction.

[@Argyuile3]

issac Arthur "Navigating is easy, it just takes some Trigonometry" me *weeps quietly*

[@Dysputant]

Easy... we just need 1 giant pulsing beacon of light... Just start making this golden throne...

[@wolfvale7863]

Two beacons would be better. You know for triangulation.

[@nayandusoruth2468]

@@wolfvale7863 true, but I think this comment was a reference to the universe of WH40k, where the imperium of man navigates by the psychic beacon produced by the emperor of mankind, sitting on the golden throne...

[@tylergladys6626]

Just gota murder a thousand psychic people per day for the evil god emporer

[@SimonClarkstone]

I do wonder if 40K got the eternally-almost-dead emperor idea from HHGTTG. I expect the man-eating lighthouse thing was 40K's own invention though.

[@Wayoutthere]

@@tylergladys6626 TOTALLY WORTH IT :P

[@rupertmiller9690]

I was born in time to see us take our first steps off world, for that I am grateful.

[@1Knightwolf]

Cheers.

[@Splaccemttv]

No i wanna be able to leave earth or go into another galaxy its cool that technology is developing but id definitely rather be in the future then 2020 🤣🤣

[@lilith4961]

Agreed

[@wolfvale7863]

So "star maps" are going to be a thing. Pirates will be happy.

[@Dedjkeorrn42]

A galactic version of "x marks the spot"

[@hunam_1]

With how many rogue planets and planetoids that likely litter the galaxy, is that really a question? There will probably be entire civilizations that will be essentially hidden from view.

[@iona2225]

*Happy Space Pirate Noises* Which I only assume to be an autotuned YAAAARRRRRRRRR

[@carso1500]

@@hunam_1 the problem with that being that it's not really feasible to hide in space (there are ways, but they are pretty fucking complex for something like a pirate operation)

[@WillPeterson]

Holy cow! I consider myself pretty educated on cosmology and physics, and theoretical star travel, but this video blew my mind with so much stuff I never considered before! What amazing content.

[@theoreticalphysics3644]

I'm reading the foundation series rn and this was something I was just thinking about.

[@twenty-fifth420]

I would imagine it gets real strange getting high speed of light speeds with interstellar highways and getting data that is actually from the past, relatively speaking (and pun intended). In short, oh boy I hope I can find a really good map from Alpha Centauri or I should have taken that last right turn at Albuquerque 😂

[@trentonarney6066]

If they perfect quantum entanglement data should be instant. Unless light speed disrupts the entanglement somehow.

[@thegreatdream8427]

@@trentonarney6066 It is impossible to send information faster than light using entanglement. Quantum effects travel instantly, but they have to be decoded using a signal travelling via classical means, which means light speed or below, so in practice there is no benefit. Wormholes or other modifications to the shape of spacetime would be necessary to achieve faster communication.

[@pro126]

Happy Christmas Isaac and team and happy Christmas to all the patreons.👌👌👍👍

[@mikeellery3336]

I wonder if our ancient ancestors gave voyages into the unknown this much thought, or if they just threw some wood together and said, "Let's go see what's over there.".

[@mrillis9259]

There were two kinds of early explorers. One who went or was sent off. The other stayed home to collect the efforts of the explorers, an slept with the wives

[@thewhitewolf58]

3:49 got to love rocket science even something as moving from a to b is fucking complicated if you actually want to find b this is why i like this channel you make it simple

[@nameofacreativevariety9985]

Morning issac! Once again you bring fascinating and amazing information to us. Everytime you go."well this could happen" you list out a really cool science fiction book idea. And i feel the sudden urge to write it!

[@captainpuffinpuffinson4769]

Sheveron 7 locked *stargate opening noises*

[@adamthethird4753]

Someday, they'll be an engineer that evaluates all these ideas as just another boring day at work. @.@;

[@PerfectAlibi1]

Perhaps even a fully digital engineer with a robot body when needed XD

[@robertkarnick1286]

One of the universal truths of human civilization is that there will always be shitty jobs that need doing

[@PerfectAlibi1]

@@robertkarnick1286 It's a dirty job, but someone needs to do it. :D

[@admiralsquatbar127]

@@robertkarnick1286 Somebody has to clean up the holodeck after Riker has "enjoyed" one of his programmes.

[@alexandremattos4046]

@@robertkarnick1286 True! LOL!

[@sab1751]

Watched it on Nebula yesterday. Great vid

[@ProperLogicalDebate]

20:32 How can you detect the merger when the merging matter is within the Event Horizon? Does Gravitons if they exist move at or beyond the Speed of Light to get away? (Think for a moment of the many tangents here.)

[@antonlencses8622]

Just google "LIGO". it should answer your questions.

[@linz8291]

Graviton can be FTL and VSL, so you can designing some gravitonic engine to the starships for interstellar travel.

[@jhmrem]

Al-go-RITH-m, Al-go-RITH-m, Al-go-RITH-m, who could ask for anything more?

[@ProperLogicalDebate]

22:11 Or you can do what Theodore Roosevelt Jr. did on D-day; "the war starts here."

[@carso1500]

It would be kinda scary to fall into a black hole or something and appearing in a empty universe with no stars or galaxies around, only the infinite void and the song of the gravitational waves created by other coliding black holes

[@waleedabbas]

This was the most awaited topic, just remembered even yesterday I was trying to find any video related to Interstellar Navigation and today just saw this!! Thanks for the upload ✔️

[@cannonfodder4376]

Watched this on Nebula last night, guess I will watch it again. 🥰 Another fantastic and informative episode as always Isaac, nothing like a new video to brighten my Thursday!

[@gaztons1115]

I havent been on this channel for over 3 years, God the memories of staying up at 4 am and binging watch your content. Oh the nostalgia.

[@krzysztofkolodziejczyk4335]

The problem with stellar cartography is that it will hoard all electricity of your starship and prevent you from having a nice tea.

[@demonitter]

Nah, we have predictions for our nearby stars for the next 10 million years, not to mention, as something that can be solved manually, a computer can solve it in less than a second.

[@krzysztofkolodziejczyk4335]

@@demonitter It was a joke mate. I was referencing one of TNG episodes.

[@ryanhawe8234]

But oh, the revamp it got between Season 5 and Generations....

[@lukasdimmler2622]

For navigation, you can simply take your telescope and look at a few stars in the vicinity. The red/ blueshift of the spektral lines will tell you your relative velocity and with multiple stars your direction and speed relative to the cluster. You can easily identify a star formation and adjust your angle.

[@USSAnimeNCC-]

The tactics and logistic of the future will look like to us what 16th century people will look at at modern tactic and logistic

[@calimerohnir3311]

I nearly had a stroke trying to read this

[@mrillis9259]

Basically the same? Stolen from past tactician?

[@charlescilek2281]

“That’s the first rule of warfare” -Isaac Arthur, pt. 75

[@xanderabbey8529]

This is such a cool topic! I've always wondered how galactic civilizations would even get around the galaxy. Star Wars had hyperdrives and hyperlanes, but that's fiction. "What would real-life space-farers actually do to get around such vast distances?" is the real nut to crack.

[@ntwalipat2]

Teleportation! That’s how! You can’t apply the technology we use on earth to intergalactic travel! It’s like comparing a conventional computer with a quantum computer!

[@Alexthealright]

Sub Light ):

[@leefletcher7527]

I actually wrote a space opera with guys navigating the Galaxy using slide rules and telescopes.

[@keshavgupta7025]

2 dislikes. Haters also have their nofitcations on lol

[@1Knightwolf]

Haters gonna hate.

[@annoyed707]

Ironically, to dislike a video about interstellar navigation is an indication that they've taken a wrong direction in life.

[@saalkz.a.9715]

Flat Earthers...

[@seriousmaran9414]

Flat earthers and space travel deniers are about it. They hate anything that contradicts their limited and flawed understanding of the universe. We are rapidly getting to the point that they will have to go live in a cave to preserve that. Which means issues disliking, unless they use the SpaceX sat system.....

[@logarithmmm]

I can't imagine anyone hating Isaac Arthur. Genuinely curious as to what the criticism might be.

[@rJaune]

Great video as usual. You always bring up things I never would have even considered. Merry Christmas, Isaac!!

[@kairon156]

These beacons sound a lot like how Light houses work. with each one having a slightly different light pulse for passing ships to read.

[@carso1500]

Because thats exactly what they are, just over sized to interstellar scales

[@ProperLogicalDebate]

13:13 Even if a transmitter stopped it would be some time before that was noticed and there would be many important messages that wouldn't get through and eventually, if still needed, need to be resent.

[@antonleimbach648]

Man I learn so much from your videos and I appreciate your passion for all things space.

[@SoldSoul4VB]

I love these videos so much. They make me they make me excited for the future 😁

[@merlinjones2660]

Depending on propulsion type star navigation is the easiest to travel using its emission as an energy source but also mapping any items there in that area

[@seriousmaran9414]

Randomly appearing somewhere in the universe would probably put you a long way from the nearest galaxy. You might be extremely lucky to find any massive object, such as a large asteroid or intergalactic comet within a hundred light years of you. nearby.

[@aleksakocijasevic6613]

I'm interested in one thing. If we the speed of light is the fastest speed in the universe, and is also the speed of causality, then wouldn't it be true to say that those distant galaxies are actually in our temporal present? In out time slice of "now"? Even though they are much older than we see them, because of time relativity, aren't they actually in the present according to our point of view? Because we could never get to them faster than c.

[@sotros1]

Exactly. There is no simultaneity, no universal Now. Each point in space-time is separated from every other point by a three-dimensional spatial distance and a time interval equal to the light travel time across that distance. We can't know anything about any part of the physical world before light can bring us the information.

[@aleksakocijasevic6613]

@@sotros1 So, I guess what I'm wondering is, does it make sense to say that we see galaxies now as they looked like millions of years ago? Million years ago compared to whose clock?

[@kj55]

I just wanted to come here and say that I love your videos I literally watch them every night You have such a soothing voice to me and it helps me fall asleep and relax thank you

[@N.M.E.]

I never expected Interstellar Navigation to be such an interesting topic! Who would've thought!!? Outstanding, as always!

[@aaroncurtis1606]

Hey; posted 10 minutes ago, I've never been this early. Thanks for your work Issac!

[@tyree9055]

"Your message was just received by Outpost America. Good luck on your journey into the void, Outpost America out."

[@annoyed707]

Rachel, Garth and Devon approve this video about how not to be lost among the stars. (There weren't many channels when I was a kid.)

[@CraigLYoung]

Thanks for sharing and Merry Christmas!

[@CrusterfunkShenanigans]

I don't know why but youtube unsubbed me from your channel, was wondering why I didnt get any updates from your new videos and noticed they had unsubbed me. Glad I found out and am subbed again, dont wanna miss any of your great videos.

[@WaxPaper]

I was just thinking about this the other day, because I was wondering how we even got to the moon so accurately, let alone how we send probes to other planets and friggin ASTEROIDS, now. It seems so risky because of how small the margin of error can be, but somehow it works and we never hear about probes getting lost. It's interesting to imagine how that would extend to interstellar travel.

[@thetruth45678]

Happy Arthur's Day!

[@perspectivedetective]

3:25 Not sure if the duplication was intentional, but I noticed this line repeats.

[@ravenlasky5286]

Not sure if the duplication was intentional, but I noticed this line repeats.

[@MuzixMaker]

Glitch in the Matrix.

[@ClamBake7525]

Merry Christmas and Happy New Years to you and yours from Lake County, OH!🎄❄☃️

[@remo5234]

So happy! The return of the “first rule of warfare “!!!!!

[@konradcomrade4845]

basic navigation within the Milky-way-galaxy and orientation should be by 3 prominently looking, not too far away, not too close galaxies. the fine orientation can then be done by a series of pulsars.

[@xxchuangtzu6186]

Star of the Magi is Matthew, not Mark. Matthew 2:1-11. Just saying.

[@isaacarthurSFIA]

yeah I mixed that one up, there's a note in the subtitles about it but that's about all I can do for 'corrections' in youtube these days

[@edumaker-alexgibson]

@@isaacarthurSFIA I'm 100% used to your distinctive and completely clear, compelling speech style. But today I heard 'The gospel of Mork' and the idea of that greatly pleased me.

[@Kelkschiz]

I think that in the future pretty much all interstellar spacecraft will care future iterations on ESA's Gaia spacecraft and similar technology. Having that along would go a long way in trying to figure out when and where you are. In short, don't think the "lost in space" idea will have a future in reality.

[@MrJero85]

If you're leaving the solar you are not going to be returning for a very very long time.

[@av3stube480]

Watching this solely to write a novel placed in the interstellar because I have a bad case of perfectionism. Jokes aside, the topic is really interesting. Keep em coming!

[@mjk9388]

Fantastic episode Isaac and team.

[@ProperLogicalDebate]

18:40 You may have started millions of years ago but as you go to it, Earthtime will seem to go faster since you are approaching the source of the light. I don't know if you will return before you left Earth.

[@SolarGranulation]

I've been looking forward to this one!

[@quantum_chezburger2279]

So have I!

[@SolarGranulation]

It was worth the wait. There were several things that I hadn't fully considered.

[@kylephelps9716]

thank you for my daily dose of existential exploration. Really appreciate your work and it helps me a lot!

[@kylephelps9716]

also thank you for the discount on my curiosity stream subscription, so much to see!

[@scottpitner4298]

Your content is some of the best anywhere for people who are always looking up in wonder 🤘🏼

[@ColdRFusion]

First rule of Christmas: Watch an SFIA video! Merry Christmas Isaac, Sarah & everyone here

[@piratehunter1]

"Sits in navigator chair" ATTENTION ASTARTES! PREPARE FOR TRANSITION TO WARP SPACE!

[@foty8679]

May the light of the emperor guide us to his enemys.

[@prozacgodretro]

Wouldn't any combination of pulsars be unique based on their ratios instead of their absolute values? About 9 minutes in, and that just occurred to me so maybe you mentioned it. But knowing the ratios of age and decay of various pulsars, you could predict plus or minus a million years what each of these would look like and their approximate locations... And then know that you've arrived at your "destination" assuming what you wanted to be there is still there :p

[@forksandspoons7272]

Many of the ship models have a rotating portion around a central axle to create gravity. I'm curious if you could spin the whole ship like a bullet out of a rifled barrel and get gravity that way. If that works it seems a lot simpler than a wheel and axle design that has mechanical bits that can jam, fail etc. Granted looking out a front the window on a ship spinning like a bullet would probably make you dizzy, but that easily solved, don't look to long. In theory you could use thrusters to spin up and then fire your rockets to get moving forward.

[@Nmax]

This is so fascinating. Thank you.

[@isaacarthurSFIA]

You're very welcome :)

[@tedarcher9120]

But what about *space detection*? How hard or easy is it to detect a dark space object like a stealth spaceship, and how effective would different means of detection be, like radar, telescopes, or infrared detectors?

[@donsample1002]

As long as you're travelling inside or near the galaxy, and staying out of really dense nebula, the mk1 eyeball is all you need to get a fair amount of orientation data. Spot the Milky Way, and and the Magellanic Clouds and you'll know your orientation. A bit of work with instruments as simple as an astrolabe, and you can get a pretty good fix on which galactic neighbourhood you're in.

[@stephenpointon]

Interstellar navigation, or how to navigate between 2 points that are moving at different rates and directions? Reminds me of a book I once read where a spacecraft was going to another star to end up finding it was about to run into a gas cloud ejected by another star . No one had noticed it because of the time from planning the mission to getting half way.

[@PhazonSouffle]

Tau Zero by Poul Anderson

[@stephenpointon]

@@PhazonSouffle thanks i was just about to go looking for it

[@PhazonSouffle]

@@stephenpointon it's a great book.

[@Rose_Harmonic]

The point about basic K2 civs beating the snot out of most fictional galactic empires is something that I frequently get hung up about. It tempts me to write stories where that is exactly what happens.

[@kskaiseraaron]

Please forgive the following dumb question... So it makes sense that navigating to a planet would be hard because it is also moving and wouldn't be in the the same place. Could this also be why we are not hearing anything with SETI? My understanding is we point the telescopes at the planet and observe. Should we maybe be pointing them were they were hundreds and/or thousand of years ago incase that civilization got wiped out?

[@TimothyAlbiez-UnhingedSpace]

Another 5-star production Issac, well done :)

[@isaacarthurSFIA]

Thanks Tim!

[@primordial-chaos00]

Can you a episode on what would happened to those humans born on others planets and different their live would be compared to those born on earth and Their relationship with earth

[@T--xo2uq]

Could it be viable to use a black hole outside the milky way as a reference? It would have quite a stable object and last for a long time. Though, you would need a planet sized telescope to track something so dark, it would still be a constant for all intents and purposes. A K-3 civilization could place a few of these telescopes who can tell where they are, then local networks could coordinate themselves relative to those.

[@agalah408]

Beacons are an interesting topic. A good example is the existing Reverse Beacon Network (RBN). It is used by Amateur Radio operators for real-time atmospheric condition and path monitoring of radio signals around the world. It works like this. About 180 special receivers, hooked up to dedicated PC's ane scattered around the world constantly scan big chunks of HF radio spectrum for operators calling 'CQ' followed by their callsign. Morse code speed and signal strength is logged. This data is aggregated in a special site via the internet. The result is a real time map of chaotic radio propagation. Networks like this are likely to exist in each solar system, cataloging the movement of particles from a grain of sand upwards.

[@AngelAndTheWolf]

I know about red shifting, the expanding universe, and the observable universe vs the actual universe, but if we could hop into a worm hole in 2021 and hop out in a spot where space is moving away from us at half the speed of light, spent a year there (local time), and jumped back to near earth local, would we jump back into 2022?

[@SupLuiKir]

Just build Dyson Swarms and use the swarm to provide the energy required to build Stellar engines, around every star you come across. If you build a *literal* Star Fleet out of your entire galaxy (or multiple galaxies), then you'll never need to navigate.

[@TheSpellwright]

I'd love the bridge of the starship featured in this video as a VR environment. Maybe hook up the panels to a bridge simulator game (I like Starship Horizons) and pilot the USS Isaac Arthur to the farthest reaches of the galaxy.

[@avishalom2000lm]

@3:40- did the audio just repeat itself?

[@sentenal01]

Yeah minor error

[@annoyed707]

The last time I popped out of hyperspace this early I had drifted off beacon and the gravity waves spilled some deity's primordial soup. When you're dealing with immortals you quite literally never hear the end of it...

[@mrnnhnz]

I was wondering what you'd do for navigation to a certain star as the first human ship to leave the Sol system. No handy navigational beams from nearby systems - they haven't been set up yet. Triangulation from quasars/pulsars is helpful, but you mentioned it might not be too accurate. But seriously, you're the navigator aboard the first colony ship to leave the Sol system, and you're heading for, say, Proxima Centauri. You have a ship that will accelerate for a long time up to very high speeds, and then flip over and decelerate for an equally long time so you end up in the Proxima Centauri system at a reasonable speed. Granted, you may not do any navigating. It might be left up to the very comprehensive computer on board, which can potentially even make course corrections. In fact, you will probably be in cryo for the whole trip. Or the folks on your ship will live out normal lives on board ship, and it'll be their grandkids who eventually disembark at Proxima. But the question remains: how does (the computer, or you,) decide in what direction to travel, so that you end up not where Proxima is now, but where it will be in, say, 80-90 years? Is there anything better than pulsars? Perhaps take readings of very distant objects like galaxies and see how local stars change position with reference to them, and judge your location and heading from that?

[@alesrozman]

The most depressing option wasn't mentioned. You hyperjump to a void with no stars in observable universe. Just pitch black darkness.

[@TmsMovies]

I always put on your videos when it's time for bed!

[@moisesarreola2649]

I came for the space topic stayed for the dialect. I legitimately can't pinpoint where you're from.

[@francoislacombe9071]

The best strategy if you fall through a wormhole to an unknown location in spacetime, imho, is to locate that wormhole and go back through it. 🤔

[@dragoonsunite]

Not sure wormholes are actually omni-directional. For starters, whether they exist or not is the first issue, second even if they do exist, my understanding is that for all but supermassive black holes, anything that went "through" them would likely be torn down to a particle stream before ejected to the other side... I think there are theories for supermassive, or more likely ultramassive black holes, that with absolutely ridiculous spins (Extremely unlikely for an ultra or supermassive) can conceivably allow passage for something "space ship sized" without tearing it to shreds, as their event horizon surface gravity is extremely mild... But anyway... The other half is the white hole, something completely unobserved, and only theoretical. Realistically the most apt explanation I've heard justifying the existence of white holes in the mathematics is that nothing "demands" time be mono-directional, which means of course that a time reversed black hole is a white hole, and since anything that can happen forward in time can at least THEORETICALLY happen backwards in time, white holes are mathematically possible, though again, probably not actually real... A worm hole is just entrance into a black hole and ejection out a white hole. Once you reach the other side, there is no "entering" the white hole, as that is equally as impossible as escaping the black hole on the opposite side because they are just inverted versions of one another.

[@brookestephen]

couldn't we send out a million cubesats to sit near rocks all over our solar system? They could be used to track trajectories and intersections in real time! If we wish to change trajectories, we can move the cubesat towards or away from their target, to nudge them into a different orbit, or just manipulate two targets to intersect.

[@bradfordhatch5085]

6:15 - Correction: The Crab pulsar/nebula is *six thousand* light years away; not a mere *six hundred.* Something you point out yourself a minute or so later.

[@josephdavis2198]

A few days ago it was brought up that the Star of Bethlehem may have been Jupiter and Saturn. The discussion was brought up because of their conjunction right now.

[@mariolis]

6:28 If that Supernova was detected in 1054 and is ~600 LY away... then the actual supernova happened when the Western Roman Empire still existed... And the light from the Pular that resulted that we see today , started travelling when humanity was experiencing the Reanaissance Perspective can be a very interesting thing...

[@dragonthumbs7727]

I guess a pathfinder organisation or an explorers guild to provide up to date mapping would be useful

[@Pfandfleisch]

Nagivation is used for ship on an ocean. Should'nt it be rather called something like "Astrogation"? Just asking.

[@muche6321]

Wiki says navigation comes from latin; navis meaning ship, agere to drive. So I'd say it still applies. Astrogation would driving a star itself, for example to change its trajectory (and its accompanying star system) to avoid being in the vicinity of a future supernovae.

[@alfredsutton7233]

I concur.

[@TraditionalAnglican]

The term I’ve seen used is “Astronavigation”.

[@jasonplant5432]

Stopped watching Isaac to watch Isaac again,wonder if this is a collaboration with joe again.( I liked that).

[@justindeloach6732]

Wow.... Never thought of a wormhole transporting you somewhere beyond your original observable universe... Scary af

[@mrillis9259]

Deep space nine.

[@brianjenkins8514]

You can overthink this navigation, though. To quote two great interstellar travelers, second star to the right and straight on until morning!

[@OrbitalAstronaut]

I want to see a video that is an index of discovered exoplanet types and main sequence stars.