Superluminal Time Travel + Time Warp Challenge Answer
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- čas přidán 21. 03. 2017
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By choosing the right path and the right reference frames, any superluminal motion can lead to information or objects returning to their origin before they depart. Matt O’Dowd will show you how to navigate such a path.
Time Warp Challenge Challenge Question - Race to a Habitable Exoplanet 1:44
• The Race to a Habitabl...
The Geometry of Causality 1:39
• The Geometry of Causality
Previous Episode
Time Crystals! Space Time Journal Club
• Time Crystals!
Written and Hosted by Matt O’Dowd
Produced by Rusty Ward
Graphics by Grayson Blackmon
Made by Kornhaber Brown (www.kornhaberbrown.com)
And the Space Time Challenge Winners are …
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Bartender says "We don't sever faster then light particles here". A tachyon walks into a bar.
Who won the exoplanet?
huehehueuhehuehue Certainly this have entered in my hall of infamous jokes that no one around me will laught
Didn't leave a tip
We don't serve faster than light particles here.
Bartender says
A Tachyon walks into a bar
Bartender was born
Darkness.
Jeremy Leyland Did the E in ‘serve’ travel faster than light and appear before the R?
I was laughing before I read this.
PBS Space Time: my favorite show I don't understand.
This one was fairly easy. (Relative to other videos on this channel of course is 😅)
This one is Easy. Try the infinite series.
agree , somewhat😁😁
It is pure pseudo science.
@@jukkatakamaa7274 GR is pseudo science !!! blasphemy !
Whenever I watch these I start out understanding what he's talking about. Then I think I know what he's talking about. Then I pretend that I know what he's talking about. Then I confess that I have no idea what he's talking about.
This video reminds me of a joke: Two cows are talking and the first says "Most people abbreviate PI to 3.141592 but in reality the decimals go on for infinitum". The second cow replies "Moo". I feel like the second cow after watching this video.
psst: "go on ad infinitum".
--Dave, have lesser grammar nazis / upon their backs to bite'em
Two muffins are sitting in a muffin tray, baking in the oven. One muffin turns to the other and says "Wow, it sure is getting hot in here, don't you think?" The second muffin turns to look at the first and replies "...holy shit! It's a talking muffin!"
Moo, too.
All I want to know is... *"Will knowing all of this get me laid?"*
I'm gonna have to go with 'moo' too?:-)
"It's possible to receive a reply to your message before the message is sent."
I must be using a tachyonic anti-telephone when I ask girls out
to the top!
I hear you. Girls are always like "yeah I'll go out with you" and I'm like "who the fuck are you and how did you get my number?"
Acetylene hilarious!
lol if real it has so many implications
nope...you're just a nerd...like me....
Kudos to the person who makes all these diagrams... phenomenal job!
I don't think this is mentioned enough. The artwork is phenomenal!
When I recommend this series to people, I always say, "O'Dowd and his amazing graphics team."
@Savage Truth Matt O'Dowd is the grizzly astrophysicist that hosts videos on this channel.
yea this channel spoils us
"My ship is _so_ fast, that it can beat _itself_ in a race!"
Michael Jackson best itself all the time.
Enough talk! Lets build that ship and really see what happens!
@A Frustrated Gamer what!?
@A Frustrated Gamer nah. We could try to use warp tech. Its reasonable. Wont work like startrek, though
We have more to worry about that, like immortality with nanobots.
@@chaoticmasterpiece I guess now we know where the star trek Borg originated from
Jajajajaja
NO
"before Albert showed us the way" love it
I thought "Who the fuck is Albert ?"for 2 seconds, tho.
St. Albert.
Vincent Snyder ALL HAIL ALBERT!
Vincent Snyder st Albert patron saint of causality, spacetime and the jewfro
What if Albert had an FTL drive and just went to the past just to give us that awesome knowledge!
7:31 "The Paradox appears to materialise out of nowhere and then proceeds to split in two"
Woah, Prof Matt just scienced the Picard Manoeuvre!
"We are temporal creatures, our experience of the universe is a thing that emerges from the forward causal evolution of the matter that we're composed of."
Thought this was such an articulate way of describing reality.
Bit of a nihilistic one, but it definitely is pretty good.
And its wrong.
All matter is merely energy condensed to a slow vibration, that we are all one consciousness experiencing itself subjectively, there is no such thing as death, life is only a dream, and we are the imagination of ourselves - the Legend himself, Bill Hicks
You can't do a lorentz transformation between a ship in a warp field and one in normal space time, thats kind of the whole point. In a warp field you are effectively removed from the rest of space time until you reach your destination. No light or any information travels between the two points. Because for spacetime itself the speed of causality is infinity as present in blackholes an inflation period where spacetime streached at a rate greater then C. So you can't change reference frames from inside a warp field to outside one using mathematics designed for a normal space time, not more then a photon can escape across the event horizon outside of a black hole. The warp field solution to get around C is not just to get fast, its to get around the limit of a lorentz transformation control universe where FTL is indeed impossible. It does this by not violating any rules but by placing the mass it wants to transport in a kind of bubble universe and then move the bubble. The only interaction between the two areas is not light or any particle but vacuum energy (so possibly virtual particles) which quantum field theory says exists, at least partly, due to the wave particle duality. Basically we can't mathematically model an FTL ship correctly because we don't have a theory of everything that balances out relativity and quantum mechanics. Thus this shouldn't be a way to disprove FTL by its nature, rather it shows a flaw in our current theories, a flaw that is very well known. Or in other words, we can't model FTL very well until we at least figure out Dark Energy as Dark Energy probably involves vacuum energy of some kind on the macro scale but using the current equations the numbers are widly off. This is just another manifestation of that discrepancy between the two models.
By Zeus...
this guy has no chill
Neat
@A Frustrated Gamer I think there is no paradox, the possibility of having a metric like that is equivalent to having a wormhole to the past. Hence, events of the "past" (cosmological past by the way) would be connected causally with events of the "future", because a photon or a particle that happened to enter to the distorted space could end up in the "past", the particle's proper time wouldn't be imaginary since it never violated the light speed limit.
@A Frustrated Gamer Just bookmarking this thread!
If you have a valid idea for building a time machine, you will most likely be getting a visit from your future self, warning you to never build it.
😆
@Pierce Lawson Interesting
Both of your accounts got created on the same day, less than a week ago.
Please don't advertise this trash for everyone's sake.
I'll assume that both of you are either bots or got hired by someone to advertise this.
Have you been watching The Flash lately 😜
I haven't heard anything yet, so I'm guessing the government took my toy away
I have no idea what the fuck he is saying
But i like it
probably the eye brows
Basically, time is an illusion and and Matter can't travel backwards because space does not work the way we want it to.
The longer short of it (the VERY quick and dirty short of it), FTL space-travel is impractical as hell since you'll be fucking with all nominal laws. Let's say a guy from a distant galaxy placed an order in our galaxy for a pizza. An FTL journey from the perspective of the pizza chain would be 100 years late. That same journey would take 50ish years for the pizza delivery guy. BUT, for the guy who ordered it, it would arrive 100 years before he even placed the order.
In layman's terms, when you start MOVING faster than light, you start to move faster than causality itself. An itty bitty delivery mission would require a super-computer AI and about a dozen or so Matts to accurately nail down the calculations necessary for a "30 minutes or less" delivery promise.
So...uh. I think FTL is just out of the picture. We need to figure out wormholes and asap since they don't factor in speeds and distances whatsoever.
JohnCaseyCB
What I understood is that while you move faster then causally you can't reverse causality. This means that while you are traveling faster than light the person who placed the order is still operating at the speed of causality. (You are both progressing forward) So what happens is that while you see the guy taking the order you are just seeing the photons emitted from when he took the order, however the actual person has still taken the order.
Think of it like a computer with a very slow refresh rate. If I am playing a game online with this computer and i get killed. I'll be seeing things constantly freeze and than skip at another event in the game. I am seeing the past, however while I am seeing what already happened, the game is still progressing to the future. So you are dead, however you haven't seen that data yet because your computer hasn't processed and displayed that information yet and therefore you are sitting in the death screen, but from your perspective you haven't died yet.
JohnCaseyCB
Wormholes and warpdrives etc don't fix anything. They just make the math work within the theory of relativity, but you're still breaking causality.
A lot of people who are excited by warpdrives etc fundamentally missunderstand this point (the comment section of the earlier video was pretty crazy). Warpdrives and co don't make the problem of breaking causality go away, they're just loopholes within relativity to achieve FTL travel without breaking the math. This is why the host said in the challange-video that people like Hawkings believ that we'll ultimatly find a more fundametal law that prohibits causality-breaking directly.
This might not even be necessary, however. Everything that has to do with wormholes and warpdrives etc relies on some form of exotic matter or negative energy to make FTL work within the limits of relativity. These things are likely to be just fictitious artefacts of the math, like Tachyons, the backwards-in-time existing particles.
He has a unique way of sounding interesting while simultaneously making you feel like you have no friggin idea what he just said.
Just bookmarking this cuz this might correspond to a real category of charm known as academic charm!
this show is just awesome. I would love to see some history on the experiments behind these theories, trying to understand how these strange notions were originally devised.
Literally sent my solution an hour ago! Dang, better get on my FTL spaceship so I can submit it a little earlier
I casually described how I thought it would work for the last video in a YT comment (based mostly on imagining it, no math or diagrams); description in this video roughly matches my description; so good enough, shows I am at least not too far off on this stuff...
+Sanders 2016 That warp drive thing that He's talking about could travel 10 times the speed of light from what I understand.
its speed depends on the ammount it warps space, which depends of the energy applied, more energy more warp more speed, so theoretically it could move infinitely quickly with infinite energy, so there is no speed limit for it, 10 20 30 1000000000000, if you have the fake mass (or real mass) to bend space with ou can go as fast as you like.
+Odon Flanagan True, but it turns out we don't need negative energy to warp space anymore. I watched a video that said all we need to do is oscillate space.
It would seem that this explains the illusion of time travel viewed by different perspectives
"In the olden days, before Albert showed us the way..."
Beautiful
Sounded like religion
About 20 years ago I was writing a screenplay about sending a message to the past. I emailed Kip Thorne (who was about 58 at the time) to ask him if my messaging idea was possible. He replied "No"...I then replied to him: "That's not what you told me at your 65th birthday party!" (True story)
Thats great, becouse it means the Message you send is from Kips perspective from the Future.
But you wood never get an answer if its true thet the Message is from the Future unles the email client you bouth wood use safes messages for more then 20y.
Great video, but I disagree with the statement that an observer on the Annihilator sees the Paradox travel forward in time. To get the velocity of the Paradox relative to an observer in the Annihilator, use the formula for velocity transform between relativistic reference frames and you get u' (velocity of Paradox relative to Annihilator) is infinite as observers on the Annihilator would see the Paradox leave the Earth and arrive at the destination at the same point in time in their reference frame. en.wikipedia.org/wiki/Velocity-addition_formula
Any chance we can get a string theory video?
Yass! ^
+PBS Space Time
I see what you did there. Kudos.
He said before that he'd be up for it, but there are a whole bunch of other topics he has to get through first so we can understand what he's talking about.
+Clorox Bleach
String theory is dead. It's like asking for Ptolemaic system or phlogiston theory to be explained.
Hmm, yeah. I understood some of those words.
Want to like your comment, but it's at 42 now, so I won't be the one to destroy that.. ;)
You infants! You mean to tell me you know nothing of tachyons and superluminal velocities achieved through the geometric collapse of space time ahead and the expansion of it behind a starship. Standard stuff here people!
Is he talking English?
"..objects returning to their origin before they depart"... I had to put down my drink... Damn you PBS... Damn you
when you see the stars, you see them in the past. the time it took light to reach your eyes. it is the same thing here. The annihilator sees the paradox in the past. the time it took light from the paradox to reach annihilator by the distance between the two. when the annihilator sees the paradox, it has already travelled the distance travelling twice the speed of light by the time it took light to reach the annihilator. real-time, they are not seeing each other travelling at their own speeds towards their own directions every second. real-time they are both traveling with every passing second. both ships experiences the same time. real-time they both exist on the same space at the same time.
Except.... Aren't the Paradox and it's crew isolated from the effects? It was my understanding that the space it's self moved, protecting the crew from time dilation and causality violations. If that's the case, what does the diagram for the *crew* look like?
Yeah, I thought that was one of the features of the Alcubierre drive.
One may not simply use Lorenz transformation to figure out what the paradox's crew sees. Indeed, these are only defined for flat Minkowskian manifolds AND speeds less than c. For one, the ship is "moving" (although you are right, it doesn't move, space contracts and expands around the ship) faster than light and spacetime is not flat. To figure out what the paradox's crew see, one should use a Penrose diagram which is much like a spacetime diagram but with some information about curvature. I assume the crew would see what's behind them in front of them because of the aberration of light (basically they catch up with light sent from behind them that passed them) while time seems to rewind for these events but not for those that are really in front of them. Other than that, my guess is as good as yours.
Corbald
Good question, I thought I had an answer, now I'm not so sure...
+Corbald I was thinking the same thing,
The space inside the Alcubierre warp bubble remains both flat and unmoving relative to Earth's reference frame. This means that the crew of the Paradox gains no benefits of time dilation to speed up their sense of their journey. But the space around the Paradox is moving relative to the space outside the bubble. That motion traces a path on the spacetime diagram, and because it's a faster-than-light path then all of the weird (and impossible) effects of FTL travel apply, including causality violation.
*Before* you transform the perspective to the "near light speed traveler", draw the path of the space ship traveling back to Earth. It will arrive in the future in Earth's perspective, as it should. Now apply the transformation to *both* paths, and it can easily be seen that the slope of the ship's return path is > 45 degrees, traveling correctly into Earth's future even in the near light speed perspective, instead of the arbitrary < 45 degree line you've drawn traveling into the past. But hey, doesn't FTL travels have slopes < 45 degrees? Yeah, *from Earth's perspective!*
Unfortunately I don't think PBS Spacetime will make a correction for whatever reason.
Shhh... you're not allowed to reveal that the emperor has no clothes!
fantastic content and delivery as usual. visuals on point. amazing stuff! thanks!
OK, this video forces me to come to the conclusion that I'm dumb 😂
I haven't dug through ALL of the comments, so this might have been brought up before. There was, as far as I can tell, a slight error in this video about the speed of the Paradox in the Annihilator's frame of reference at about 8:00 minutes.
The two points in space-time that we're interested in are the launch of the Paradox and its arrival at the planet. The first one is at position x1 = 0 (i.e., at the earth) and t1 = 100 years. The second is when the Paradox arrives at the planet, x2 = 100 LY and t2 = 150 years.
We can now use the Lorentz Transformation to find these two points in the Annihilator's frame of reference. The velocity v = 0.5 LY/year. Therefore, the Lorentz factor is 1/sqrt(1-v^2/c^2), or 1/sqrt(1-(0.5)^2) = 1.1547. t'1 = 1.1547(100 years - (0.5 LY/year)(0 LY)/1^2) = 115.47 years. t'2 = 1.1547(150 years - (0.5 LY/year)(100 LY)/1^2) = 115.47 years. In the Annihilator's frame of reference, the Paradox leaves Earth, passes the Annihilator, and arrives at the planet all at the same time. I will leave the calculation of the x locations in the Annihilator's frame as an exorcise, but they are not the same.
Another way to consider this is that the speed of the Annihilator (in Earth's frame) is 0.5 c. The Paradox's speed is 2.0 c. Given the conventional arrangement of a space-time diagram, these are the inverses of the slopes of the "world lines". They are also the inverses of each other, so they are symmetric about the speed of light, which is always a 45 degree angle, or a slope of 1. If we transform to the Annihilator's frame, its world line is now vertical. That doesn't break this symmetry, so the Paradox's "world line" is still symmetrical about the speed of light line, so is horizontal. It is everywhere at once.
Thank you,
Tim
Yeah, when I plotted minkowski diagram for this scenario I noticed the same thing. But, when I saw the video and it had a slight slope, I just chalked it up to maybe some imprecision in my hand drawing. But if you did the math, I'll go back to relying on what I saw myself.
I did my "doodling" in a CAD program, so I was fairly confident about my results. The inverse slope thing also sort of jumped out at me too.Sometimes having studied math and engineering comes in handy, but I need to read the question better. If it says "What did they see", you need the light paths!
I found the same thing. Here's my calculation:
Let (x, t) be the space & time coordinates in Earth's reference frame, and (x', t') be the space & time coordinates in the Annihilator's reference frame.
The Lorentz transformation is
ɣ = 1/√(1 - v²/c²)
x' = ɣ(x - vt)
t' = ɣ(t - vx/c²)
Since we are using units of light-years and years, the speed of light (c) is 1 light-year/year, so the transformation simplifies to
ɣ = 1/√(1 - v²)
x' = ɣ(x - vt)
t' = ɣ(t - vx)
Also, the speed of the Annihilator (v) is 1/2 light-year/year, so
ɣ = 1/√(1 - 1/2²) = 1/√(3/4) = √(4/3) = 2/√3
x' = (2/√3)(x - t/2)
t' = (2/√3)(t - x/2)
Let event A be the Annihilator arriving at the destination, event B be the Paradox leaving Earth, and event C be the Paradox arriving at the destination.
In Earth's reference frame,
A = (100, 200) [reaches the x = 100 light-years point at time t = 200 years]
B = (0, 100) [leaves Earth at x = 0 at time t = 100 years]
C = (100, 150) [reaches the x = 100 light-years point at time t = 150 years]
Transforming to the Annihilator's reference frame:
A = ( (2/√3)(100 - 200/2), (2/√3)(200 - 100/2) ) = ( 0, (2/√3)(150) )
= (0, 300/√3)
B = ( (2/√3)(0 - 100/2), (2/√3)(100 - 0/2) ) = ( (2/√3)(-50), (2/√3)(100) )
= (-100/√3, 200/√3)
C = ( (2/√3)(100 - 150/2), (2/√3)(150 - 100/2) ) = ( (2/√3)(25), (2/√3)(100) )
= (50/√3, 200/√3)
In the Annihilator's frame, the events B & C occur at the same time: t' = 200/√3 years (~ 115.47 years), thus the path the Paradox takes from Earth to the destination is horizontal on the Annihilator's space-time diagram.
The clearest way that we can see that the graph is in error is that the transformed Minkowski has the Annihilator reaching the new planet in 200 years BY THEIR PROPER CLOCK. This is obviously incorrect, as it violates many fundamental principles of relativity.
If one properly lorentz transforms the intersection point of those two world lines, you would find that the Annihilator would reach the new planet after 20√75 years or about 173 years.
Tim Rumph 🤯
You lost me on this one. lol
Vartazian360 yeah me too. Is there a ‘scratching my head’ emoji?
After watching this video twice, i understand it and i'm fascinated as always.
I.... am picking up the pieces of my scattered over the room. Mind blowing
Thanks for the cool video. I was just talking to a friend last night concerning time dilation and space travel and I was wondering what are your thoughts on what we discussed. Essentially he had asked me what would happen if we were to be able to travel at the speed of light. I told him that we would approach infinite mass and would take more and more energy to be able to travel faster and that time dilation would become an issue. That said though, I told him it is possible that we could accelerate to a significant fraction, as much as 75% with traditional means given some time and some assistance of gravity assists through very careful navigation. He was surprised and asked if that meant that we could travel to other planets and I responded yes, we could, but that the time dilation would be a problem. At 75% the speed of light I roughly calculated (very roughly based on a post saying that it roughly goes at the square of the percent speed of light difference) that the time dilation would be on the order of 1 second = 1 minute to the observer, or 60X the difference. At that speed it would take around 5 1/4 to 5 1/2 years to reach our nearest neighboring system, but to people outside the ship almost 300 years would have gone by. Then factor in a return trip and 600 years. In that time, we'd probably have better technology such as warp drives where space is warped so that the time inside the bubble and the time to an observer would be the same. Using these warp drives would allow us to travel faster than light without the undesirable effects of time dilation and increase in mass. I did note that it would take a lot of mass to create a warp bubble and there is also the problem of forming and collapsing the bubble, but that through clever math, the mass needed has been reduced from a solar system mass down to around a planet Jupiter size mass, so in the 600 years, we could possibly solve this issue. That brings up an interesting question I pose to you (and anyone interested in postulating with me), namely, assuming all the other issues such as fuel, acceleration, deceleration, etc. were also solved and given that by the time a ship would reach our nearest neighbor would likely be longer than the time to solve the issues with creating and using warp bubbles, should we even send ships towards these distant objects, or should we wait until we have warp bubble technology? On the one hand, we can gather information in the mean time of what lies between, and there is no guarantee warp bubble technology will be feasible in the intervening time, but on the other, if warp technology is developed, the travelers would only find themselves arriving to an already populated planetary system...Exploration of our own solar system is a given as it is on the scale of 20-30 years travel to the edge and greatly enhances our understanding of how the universe works, but missions to other solar systems...that is the big question. What are your thoughts?
Some other things to consider if we do use warp bubbles:
All space objects positions and velocities would probably need to be noted for two reasons. The first is that while small objects (under a cm) probably would become just dust as I understand it, the effects of warping through larger objects, especially planets (heaven forbid stars or gravity wells) is largely unknown guess work. The second is that if you do need to avoid going through objects, you can't just rely on their observed current positions. Even observing Mars from here on Earth, we are seeing minutes into the past. In fact, if the Sun were to explode, we wouldn't know for 8 minutes. So if traveling at warp speeds, we would need to know their current actual positions.
Also, how far out from a target planet would we need to stop or start our warp bubble capable ship? Too close and it might rip the planets apart. Could we even enter another planetary system, let alone construct our warp bubble within our own? Or would the planetary mass destabilize the orbits of all the solar system objects? Even a Jupiter size mass object being positioned anywhere in our system would probably destabilize it, so are warp bubbles even possible for space travel?
Finally, how in the heck do you shift a planetary size mass so as to create the bubble to begin with and shift it back to collapse it at the destination? I imagine the one pebble at a time argument here would not work, but maybe it could?? If so, at what point does acceleration due to gravity stop and the bubble form where you are able to travel faster than the speed of light? Would this method violate general relativity? Logic? My mind? (Definitely the last one...it is starting to hurt, so I'll stop here.)
What do you think?
If the Alcubierre drive works as intended, wouldn't the extreme induced curvature of spacetime and the moving spacetime itself break the flatspace diagram, rendering this simplified analysis invalid for the specific case of the Alcubierre metric?
It doesn't matter. Whatever weird metric stuff goes on around the ship, if you move your perspective out far enough you can model it as a superluminal point-like particle and the reasoning is perfectly valid.
Doppelrutsch damn hadn't thought of that. thanks, that's pretty clever!
You are correct. The warp drive reshapes spacetime so these paradoxes don't happen.
right, in a warp drive, space in front of one is contracted and behind one expanded.
That means, the space ship itself doesn't actually move at all, nor will experience time dilation effects.
It is still true that an observer on the other world line slower than the speed of light would see the ship twice or even with reversed causality adding up the received light.
But that is only an appearance.
Ok, people are getting confused again here (I had this debate several times). The Warp drive does not prevent paradoxes. It does not matter in what weird shapes spacetime is squished. Just think about the Lorentz diagram. Then mark an event A at the origin and an event B somewhere outside of the lightcone of A. Now if you have any way whatsoever to be present at A and B you can use it to time travel as shown in this video. It does not matter one bit how. Use a warp drive, a wormhole, or walk over a rainbow bridge - it does not play into it at all. Neither does how much time the way took from your perspective btw. It's only about being able to leave the lightcone of an event.
PS: If you are so focused on Warp drives, in the very first paper by Alcubierre he points out that it could easily be configured to serve as a time machine and later papers expand on this, including some forms where it's possible to have causality violations within the warp bubble itself.
All of these PBS youtube shows are amazing
oh my god i just realized they did this in star trek. this is the picard maneuver!!!
The EVE Online Tengu at 4:30 though
Did PBS ask CCP to use the tengu
they did, they have it linked in the challenge video. (The one before this one I think).
Damn, I loved that ship. Looks sexy. And I loved missile boats in EVE ;p
yea, and it's much more faster than light:)
Think that Tengu would need a jump gate to make that trip. Plus if their was TD in local .....ughhhhh.....
Love your series! I recently came across this:
In 2016 a Japanese physicist, Dr. Takaaki Musha, wrote a paper entitled, “The Possibility of FTL Space Travel by using the Quantum Tunnelling Effect through the Light Barrier.”
Any chance you can look at/debunk this?
I think they already had by the time of the video, just go down the video list.
Survey complete. I hope you find my feedback useful.
I wanted to reiterate here though what an outstanding show you guys produce. Don't fret too much about Patreon rewards. The show is the reward.
I've thought about this for a long time and it just makes sense
Step #1
Load some Moscovium (Element 115) into a mini particle accelerator with an add-on heat-to-electricity converter.
Make sure your Moscovium has 115 protons and 184 neutrons so that the half-life is greater than one hundred years.
Step #2
Shoot a proton into your Moscovium so that it becomes Livermorium for a split-second before reverting back to Moscovium.
Inverse beta decay happens, and the proton becomes a neutron plus a positron.
The neutron undergoes beta decay, and becomes a proton plus a neutrino plus an electron.
The positron and electron collide, and release energy.
The neutrino hits another proton in the nucleus, and causes another inverse beta decay.
Step #3
Use the energy from the positron/electron collision to amplify the [strong nuclear force] holding the Moscovium together such that the gravity field envelops and encompasses your space-faring ship.
This creates a bubble that is outside the normal space-time fabric.
Step #4
Travel faster-than-light by creating a gravity down-slope in front of your space-faring ship using focusing amplifiers that bend space-time in front of your ship.
This causes your bubble to be in constant free-fall in a given direction until you stop focusing or turn-off your mini particle accelerator.
Step #5
Laugh and enjoy this bit of fiction ... or is it fiction?
lol
(taken from Area 51 forums/threads/posts)
It's fiction :0
cool tho
I'll be the first to admit that the mathematics behind this are beyond me. They are farther advance than anything I have formally studied. That said, it feels to me like there's something being misinterpreted to reach the conclusions reached in this video.
I think the problem is choosing a reference frame. Would there not be some reference frame that is static to the fabric of spacetime, and then therefore that any other is therefore relatively in motion and then no longer able to be treated the same under transformation? Like, if that 2c ship were to fly for 50 years, turn around, then fly back for 50 years, wouldn't 100 years have passed at its point of origin? The ramification of time dilation is that maybe time would have to flow backward on the ship, but clearly that doesn't make physical sense (hence the asymptotic energy boundary in accelerating past c... that results from the dilation of time such that time effectively stops at c... sort of like a zeno tortoise, but with increasing speed instead of advancing position. As time slows down, the power it takes to provide more acceleration grows infinitely and crossing that c boundary, at least from the perspective of the ship, would require infinite power since at c, time no longer passes.)
We try to get around this by invoking the notion of an Alcubierre drive so the ship is contained in a spacetime bubble and does not experience dilation. Wouldn't this then eliminate any of the time travel aspect of FTL? Suppose a completely static frame is trapped in the bubble and translated through the galaxy at 2c for 50 years in one direction then 50 years back... assuming negligible relativistic effects at the origin point, pretty much both the bubble and the origin would have experience 50 years of tick-tock on the watch.
The more I think about it, the more I'm driven to the conclusion that the discussions in this video and the few preceding it are what Fermi would have called "not even wrong."
Just the trick to starting the day! Now working on the car this Saturday doesn't seem all that of a problem to tackle. Cheers.
This is easily my new favorite channel!
"I'm Commander Shepard and this is my favorite channel on CZcams"
"traveling FTL is traveling back in time"
Only if done in normal space. Alcubierre drive distorts space-time but doesn't transit the passenger backwards in time.
Yup, nothing can move at > 1x light speed, you can travel to the future for real but not in the past, and I think my human mind is right when not being able to grasp the concept of travelling backwards in time ; and since time warp doesn't even make you move (space does, not you), it wouldn't even make you travel to future
Is there actual basis for this or are you just saying that? All the Alcubierre drive does is push pull or contract, expand space around it. It isn't transitioning to another set of physics or rules by bending space-time. If you travelled sufficiently faster than the speed of light to arrive back to your dock before ever having left, then before you left you'd have seen your future selves appear at the dock before you leave in the first place and when you travel back, you'd see your past selves ready to leave thus you travelled back in time.
@@Jhakaro you can't move faster than light IN space, but space ITSELF can
Put nanorobots and so on with quantumsyncs inside the tunnel and put it outside like boeingen and use avatar systems in different pasts and make network management.
@@Jhakaro The Alcubierre drive wouldn't send you back or forward in time because the ship isn't moving. It warps space time to achieve FTL. Because the ship isn't exceeding the speed of light nor is it moving you wouldn't travel backward or forward in time.
For a object to time travel it would need to reach light speed or surpass it by actually moving which again doesn't happen with a warp drive.
At 6:57 Actually, the paradox is not traveling forwards in time wrt the annihilator. The "world line" of the paradox is perfectly horizontal (with the numbers you gave) in they annihilators frame. Remember the annihilator time axis in earth frame has slope v, or 0.5, which is the same slope 1/v, or 1/2, of paradoxs "world line" in that frame. The journey would appear instantaneous.
Yep.
Since the slope of the travel line of the Paradox is less than 45 degrees, it's entirely outside its OWN light cone the whole way. And, just like there's some proper Lorentz transform to take an arrow from the origin pointing to any one point in the forward/backward light cone, into an arrow pointing to any OTHER point in the same light cone? If your arrow is pointing to a point OUTSIDE both light cones ("elsewhere"), there's a proper Lorentz transform that leaves it pointing to ANY other point "elsewhere". Including ones on the slice perpendicular to the original time axis, for an apparent zero-time travel time in that frame.
(Since simultaneity is meaningless, there's no way to KNOW at the origin that the travel time was zero in that frame until something gets back from the destination. Non-FTL stuff is gonna take a while to get that info back...)
This move-the-arrow-around-in-elsewhere is the basis of being able to get another arrow from the destination point BACK into ... the past lightcone of the origin, where the first arrow started from -- and therefore timetravel. You just need to be able to change the Paradox's velocity enough in the right direction relative to its destination, once it's there, that it can be far enough 'down' the past light cone, out there in elsewhere, so that it can fly back along its 2*c slope and still hit points in that past lightcone of its origin.
--Dave, writing FROM THE FUUUTURE
Sub loom in all LOL, space puns are hilarious, especially the confounding of weaving, with moving swiftly through space. Though, curiously one does move faster when secured in place.
4:21 Matt I want that song! :) Love it! Great work Matt!
The Tengu isn't known for its speed.
No fucking way
but slap a 100mn on it and it wont ever stop
not outside warp. 3AU/s is considerably faster than light
But by definition the warp drive ship is not "moving" its warping space in front and behind it.
Then how has it moved anywhere when the drive is turned off and you want to get out at your destination? The warped space returns to normal and you're still where you started.
So is portals +()- moving energy. Warpdrive spaceship or portals.
negative charge is like exothermic reaction contract space blue shift.
Positive charges endothermic expanding space red shift.
Think eye of tornado or yin yang the earth middle equator.
All about equilibrium, as long as spaceship or portal bridge is same equilibrium.
If equilibrium is same then passengers of a warpdrive machine or a portal.
It means they have not blue shifted or red shifted. Their time and space should be relatively the same constant rate, as they move through space.
But if your equilibrium shifts then your space is still relative to those shifts.
So if you shift blue you might move faster into time as it contracts around you.
Anything moving slower then traveler would appear red shifted and slower.
If traveler is shifted red as one moves through space.
It could mean traveler is after leaving earth. Could appear red shifted in space if seen moving slower then earth speed.
earth would technically move into travelers future faster.
To the traveler the earth would be viewed if could blue shifted and appear to move faster like a gamma ray.
@@spiralinguniverse8159 That was some of the most creative bullshit I've read in a long time. It's too bad that you don't know what the fuck you're talking about.
Can you go back in time (via FTL round trips) in order to refuel with the same stuff you consumed to go FTL in the first place?
No, because the time travel is only from the point of view of the near-lightspeed reference point, not Earth or the warp ship. There is no actual time travel.
Yes, that is basically the writer's paradox : who wrote the book? I mean assuming FTL travel is a thing, you may refuel with the fuel you consumed to go FTL.
Arioch IV ok, good. I thought that's what it meant, but the video was like a temporal version of Ball & Cups. Sometimes it really annoys me that mathematicians flip the script on cause and effect. Math reflects reality, reality does not reflect math.
Can the ship get back to Earth before it left? No, therefore no time travel would have occurred.
Maybe the appearance of time travel is in fact reflective of a perspective that is not possible.
but then you wouldn't be able to take your trip in the first place due to the fuel being gone, or you're future past self would need a different lot of fuel, meaning you didn't actually refuel using the same fuel. And then you are into to dreaded time loop, or alternative reality/universe.
Basically, Earth still has moved on. So, you would think you are at the same time and space as Earth - but not from the perspective of Earth. Causality still rules! ;-)
"Rolling down the causality hill" I'm going to need a helmet.
Finally I understand why this video ran backwards, when I was watching it the day before it came out!
The only youtube video that blows my mind in 5 secounds
Love these vids, thanks guys. Also.. my first ever first comment on any YT vid! :)
and nearly the first of this video
People like myself (IT guys) can tell your lying haha.
ryzen?
I love these videos too. Great job PBS Space Time. Keep up the good work!
+BattousaiHBr xxx
What I find hard to believe is the idea that simply passing one's own photons places someone physically into the past instead of simply being ahead of the range of visual perception.
I'm so happy that you mentioned a Sophon!
Mind-bending. I have more reading to do about the conformal diagram of a fully extended, Schwarzschild black hole...the somewhat complex version jotted down in my notebook has some fundamental time dilemmas that need working out.
If travelling superluminally is *fundamentally* the same thing as time travel, how does this affect galaxies that move away from each other superluminally due to the expansion of the universe? Shouldn't we see weird time-travelling affects from this?
By definition, travel or signalling between them would not be possible (unless you've got some form of FTL already), so no opportunity for causality breaking...
Because they're not really moving, space itself is expanding, this means that no information can ever travel between them. In practice, the only wonky effect that occurs is that these galaxies cannot contact each other faster than light. If they could, then we would see time travel effects.
"They've gone to Plaid!"
God these vids are just too awesome. Please keep up the awesome work guys :) Great channel!
this is the best youtube channel to watch while smoking weed,hands down.
Now that I know the answer lemme get in my FTL spaceship, go back in time and send the correct answer...
So to the captain of the annihilator sees your ship spontaneously appear out of nowhere and split in two opposite directions? correct me if I'm wrong but doesn't that sound similar to how subatomic particle pairs appear out of nowhere and immediately annihilate each other? I think I'm just connecting unrelated patterns but it would be interesting if there was some connection there.
I get the same questionable intuitions
Henry Smith
Unrelated. The ships visual effects are just a trick of the photons emitted by a ship travelling faster than c, while they're travelling at c. the virtual particles are a feature of fields. the quantum field wants to be at its maximum entropy level, and virtual particles actually allow that to happen.
It's like the single timeline case, on the left you see spaceship travelling backwards. But on your right it travels forward (because it went past your line)
took the survey; glad to help in my small way!
Another cool video. It's been pretty well known that FTL travel will take you back in time (first Superman movie, for example), but I'm surprised no one had mentioned how this is a solution to the twins paradox. Here's a challenge question: how much faster than light would you have to go in order to arrive at Alpha Centauri exactly when you left earth (assuming instant acceleration). :-)
Hi, isn't that so, that with Alcubierre drive creates a bubble of flat space, so that the reference frame of the observer on Earth and the occupants of the spaceship remain the same ? Therefore, the diagrams You presented do not apply to the Alcubierre drive powered spacecraft, and also time travel is excluded.
Olga Szklarska I had that same question last week. My understanding is that the Alcubierre drive doesn't experience relativistic space or time dilation. So how does that change the situation here?
You are right about the Earth's reference frame being the same as the Paradox's reference frame.
As for the travel backward in time, I agree you cannot do it if the Alcubierre drive is the only thing you've got, but you can do it if you combine it with a "traditional drive" (which applies the Lorentz transformation to your coordinate system).
Yep. There are more questions though: it is true, that the space itself can stretch at velocities higher than that of the light speed. Yet gravitational waves speed is the same as the speed of light, as observed last year. The Alcubierre drive does stretch and expand space, so at first it looks like it could beat light speed, BUT the result of space deformation looks like a gravitational wave, so it's limited by "c" speed. Isn't that so ?
Olga Szklarska C, the speed of light in a vacuum, doesn't apply to space itself stretching or contracting. look at the universe's expansion, which is expanding faster than c. atleast that's how I see it.
That being said, the alcumbiere drive requires exotic matter, which were not sure even exists.
Flat space inside? Yes. But ... how are you gonna show that the spacetime axes of that flat space inside are the same direction as those outside? Sure, in the ship's frame of reference its time points up and its space are perpendicular... but if you want to see how those connect to or compare to Earth's =while the drive is on= you can't ASSUME they're gonna end up the same direction and that the ship therefore thinks it's motionless =relative to Earth=.
Another way to see this is that to find out how the outside universe looks to the SHIP while the drive is on and the bubble is moving, you gotta trace the light-ray paths =through the warped zone= where the drive is doing its bubble thing. It's not as simple as "spacetime is flat where the light ray starts and where it ends, so it looks like the ends don't move relative to each other". The reference frames are NOT guaranteed to match, and I would be really surprised if they did. After all, any inertial frame moving at any constant velocity relative to something in flat spaceimte ALSO has flat spacetime...
--Dave, wikipedia doesn't give me enough background to do the math in my head, alas
invalid... a Tengu can jam the ship before enter in wrap. the tengu .. such op ship I love Caldari ships
Just don't die in one :)
Got 3 jump clones . So i very much safe .. wait it is a tech 3 didn't ?. But a Nestor is not match against a tengu
You lose skills if you die in one, doesn't matter if you have jump clones.
took me forever to re-find this, i'll have to like it.
JUST BLEW MY MIND. I guess I'm staying on earth and traveling no where. DAMN
Wouldn't faster than light speed travel do wacky things to the matter of travelling particle? How would a particle of finite mass behave under these hypothetical conditions, and what's the overall heat balance of the journey?
Ankit Sethi it sounds like u are assuming that the particles themselves have been accelerated beyond the speed of light...
That isn't possible. As u approach the speed of light the energy required to further accelerate the mass increases exponentially towards Infinity. The forms of FTL often discussed do not face this head on, they find a work-around. In the case of warp drive, the ship does not move faster than the speed of light relative to it's local space, it makes space smaller in front and stretches it out behind. In so doing the ship travels through less space than a photon on a parallel path, allowing for potentially faster than light travel without actually being accelerated beyond the speed of light
So time travel is basically this contraction of space and time relative to the observer. Correct me if I'm wrong, but a photon emitted eons ago and constantly travelling at light speed sees everything (to anthropomorphize the poor sod) as one instant, galaxies, stars and planets forming and dissolving in the literal blink of an eye. Could it see the beginning and the end of the universe as the same event, and what does that imply for hypothetical particles that can contract it beyond the rational?
Ankit Sethi yes, a photon does not experience any passage of time as it has no mass and therefore travels at the constant speed C. I don't think it could even hypothetically "see" anything.
In FTL you're not actually traveling at FTL. FTL is a hack of space time.
In theory couldn't super light speed particles exist but just have no way of interacting with our sublight speed particle based perception of the universe?
if, in theory, such particles exist, they effectively TELEPORT themselves through the space of the universe, through some sci-fi teleport device, or by some still unknown, undiscovered physical law. the moment they teleport (if they could) - they would appear to pop out of nothing, into existence. The moment they do, they would start interacting with sublight particles, but not before that, during the process of teleportation. And this, only if it is physically possible, in the first place (the teleporting process).
Thank You PBS. This video made it clear that this "space time traveler" is infinitely more confused than they were before the video began.
As a fan of Liu Cixin, I was pleasantly surprised to see a nod to his "The Three-Body Problem"/"The Dark Forest"/"Death's End" trilogy. Though he does play fast-and-lose with some things (like the Alpha Centauri system and quantum entanglement), his speculative physics is interesting and his notion of weaponizing physics is terrifying.
Wallfacer Matthew O’Dowd, I am your wallbreaker. ;-)
How many answers to the challenge do you usually recieve? Just trying to figure out the probability of winning a shirt. :D
42
In my opinion, traveling back in time is not possible, but into the future is sort of possible. But how could we ever travel back in time, when things don't exist anymore ? Just the light remains to show us what there was, but it ain't actually there anymore.
So stop with back traveling in time, we already proved that it won't be possible ever. This is not how the space and time works, it's a linear event, when it past, it dies, what we see is only the light of it, but if you manage to go faster than the light itself, which is not possible for the moment (hope one day it will), you will still not go back in time to see what was there, you would see the present instead. Future is possible, past ain't.
Nice video, but hard to understand for non english born.
Travel to the future is easy; just did it, did it again........Stopping in the present is also impossible since the present exists for no length of time.
It's not really a matter of opinion
Can someone tell me if I've got this right?
Say you're in a space ship moving at 100mph shy of c relative to a stationary destination (Planet X). Inside the ship everything would appear normal, as if everything around you (lights, switches, sex dolls etc..) were stationary and the ship was the exact shape (internally) as it should be. Now if you fired a gun in the ship, and the bullet was fired forward (in the same direction as the ship's forward motion) at 1000mph, then the bullet wouldn't really exceed the speed of light by 900mph because the ship would (to a stationary observer) contract from front to back such that the bullet is taking the same time to cover less distance. The squashing of the ship is such that any internal projectile would have to be fired at what would appear to be the speed of light from inside the ship in order to be perceived as the combined velocity of the ship and projectile as c from outside the ship?
ADD EDIT: Or is it just that events occurring inside the ship happen more slowly to an external stationary observer, so the bullet would appear to travel much slower than 1000mph, slow enough so that the combined velocity still wouldn't exceed c?
If you want a visualization of the Paradox ship materializing and then racing off in two different directions as described around 7:30, look at the wikipedia article for tachyons. It has an animated gif of how they would look.
I am sorry but, I have an unrelated question. If PBS experiences budget cuts, would it effect the funding for PBS supported CZcams channels? PBS Space Time, Brain Craft, Physics Girl, It's okay to be smart, PBS Infinite series, I am subscribed to all of them, and I am a little afraid that I could loose some of my most favourite channels. Thanks for responding in advance, and if you wanna stay out of political stuff, I would understand.
Isn't that what their Patreon is for? Correct me if I'm mistaken, but I'd imagine that the majority of their online content is probably funded by the audience. :)
If majority of the funding for the channels does come from the audience, there would be no need to worry I guess
Since this channel only started its Patreon account a little while ago (3 or 6 months back, I think), I assume most of the funding comes from PBS. In other words, this channel (which I love), like an elderly person with a preexisting condition, is most likely about to enter a world of shit.
Δt' = Δt / √( 1 - ( v² / c² ) ). If v > c, then 1 - ( v² / c² ) < 0. That makes √( 1 - ( v² / c² ) ) imaginary. That makes Δt / √( 1 - ( v² / c² ) ) also imaginary. That makes Δt' imaginary. Which means you aren't going backwards in time. You're going sideways in time, since that's what imaginary numbers do in directions. Weird.
Well... no... a negative spacetime interval means you are measuring length, not time. Time is not defined for FTL trajectories. You cannot use time dilation formula in this case.
William Barnes is that a literal "sideways" or a metaphorical "sideways"?
I guess it's because imaginary numbers are perpendicular to real numbers, hence sideways
William Barnes Nice move! have you ever heard of the invariant set postulate?
It's a literal sideways, and the literal sideways of a duration in time is a length of space. Or perhaps a thickness in quantum world amplitude.
But it's probably nonsense anyways. If such a situation were possible, one could harvest over-unity energy from it. And that means they would form spontaneously and unstoppably because the return on energy would be higher than anything it could possibly cost to make. The empty void of space would immediately ignite into infinite unquenchable fire.
The Annihilator: Tengu-class cruiser 😂
Did your survey....hope it helps! Keep up the good info!
So by my understanding, by traveling faster than light, one could catch up to the photons which havent yet been intercepted by other matter, but that's all they'd be. Photons. Even then, you'd need to gather all of the photons which have spread out over massive distances in order to get a coherent picture of one singular point in the past. This essentially would mean that speed alone is not enough to travel through time in any real way. You'd just be catching up to emitted photons.
yep, which is why the idea that ftl=time travel being so pervasive in physics annoys me. All of the physicists seem to be using a model where the passage of time is entirely defined by what you can perceive of an object based on light.
Maybe this would make more sense if I smoked one before watching.
Nice video. I am always delighted when Pr O'Dowd dives into the realm of Sci-fi to demystify it BIG TIME.
We cannot help but dream of doing FTL travels, simply because we do not enjoy the thought of witnessing our own world lines disappear. Ironically, fancy FTL travel is the number 1 pathway for destroying our own world line. (Number 2 being an enthusiastic jump into a BH's singularity, of course).
Still, what a cool way to die...
Such a unique utube channel never change please
How to get rich with super-luminal speeds:
Make a FTL-capable spaceship. Fill it with gold. Engage hyper-drive to arrive in your starting location 1 day ahead of when you were planning to leave. Now you have two spaceships filled with gold. repeat process until satisfaction is reached. Sell the gold. Profit.
your other instances would want their shares. the world would be too small for all of you. you'd have to start plotting against them before engaging the ship.
Why this guy remind me of lord faarquad? Lol
God bless you all for thinking!.. Thank You!....
Thank you. That was clear and clarifying.
I love Astronomy!
This is physics. Astronomy would be finding orbits of astronomical objects which in itself is also physics
This is physics and astronomy
You make two incompatible assumptions that cannot be both true :
Assumption 1 (implicit): Einstein's 1905 constant-speed-of-light postulate is correct.
Assumption 2 (explicit): Superluminal motion is possible.
One of the assumptions is true, the other is false, and that's it. Causality, traveling back in time, etc. are irrelevant. In the example below, if the deactivation device is able to send a faster-than-light signal to the bomb, then special relativity ends up in a contradiction: the bomb explodes in the frame of the train but does not in the frame of the tunnel. We conclude that Einstein's constant-speed-of-light postulate is false and that is the end of the story:
www.people.fas.harvard.edu/~djmorin/chap11.pdf
pp. 41-42: "11.6. Train in a tunnel. A train and a tunnel both have proper lengths L. The train moves toward the tunnel at speed v. A bomb is located at the front of the train. The bomb is designed to explode when the front of the train passes the far end of the tunnel. A deactivation sensor is located at the back of the train. When the back of the train passes the near end of the tunnel, the sensor tells the bomb to disarm itself. Does the bomb explode?"
It's the distance that changes. It's not a constant. Superluminal motion naturally occurs in ejecta around Blackholes, and Quasars/ Pulsars in motion. Quasars/Pulsars due to the event horizon's space crunch being crammed against the Quasar/Pulsar itself as it moves.
Was the "Hopefully your rejuvenation tanks are still working" comment a reference to the old Firaxis Alpha Centauri game? If so I might be in love.
We can utilise High energy protons moving near light speed to collide cosmic strings to create streching spacetime curve so as object encircling around them can travel faster than speed of light according to its reference frame to time travel.
If I understand this properly then this serves as a proof by contradiction showing that FTL isn't possible. I'm wondering if this is a result of the math (ie the transformation not being made to handle this) or of the underlying physics.
I read "when we introduce superluminal travel things get messed up" as "the maths weren't written to take superluminal travel into account" it looks like it's the transformation when switching perspectives that messes things up.
If you think about it we're all carrying our own clocks and they're all moving forwards therefore no matter what we do the other clocks are only going to progress.
PBS Space Time I sent you exactly this answer with a gif animation, plus writed extra answer about how to travel to past of the Earth's reference frame. I was looking forward this episode to know if my answer is correct or not. Sadly my name is not appeared on the screen as a winner despite I answered all questions of this challange. :(
Elnur Hacıyev they selected random correct answers, meaning they received too many correct ones.
Awww poor little you....... Grow up.
Random is the only great equalizer for too much good answers (with or without fancyness). #BlameTheRandomness
+chriswillb Come on, person. No need to be like that.
I love this channel so much.
So that is how Goku is doing his double image move!
Notification Squad
Reporting my self
Reporting in! But also giving this a thumbs down because I hate seeing these threads early in the comments. ;-p
Kip Thorns book _Black Holes and Time Warps_ is the best thing I've read in this subject. He starts and ends the book with a fictional spaceship dealing with some very strange affects of Relativity. It's amazing and worth a read.