austenandrews

Re: Instantaneous Communications plus Time Dilation Equals ??? So does that clear anything up? The train is moving relative to the photons, except in the one frame of reference where the train by definition is not moving at all.

Re: Instantaneous Communications plus Time Dilation Equals ???

Re: Instantaneous Communications plus Time Dilation Equals ??? It's a textbook example. There are two photons. One travels at c and strikes one end the train car. The other travels at c and strikes the other end of the train car. These two events happen in every frame of reference. The bone of contention is the idea that these two events have some concrete order. That's an illusion.

Re: Instantaneous Communications plus Time Dilation Equals ??? The photon only does one thing - travel at the speed of light and strike one end of the train. That's all it ever does. It does that in every frame of reference.

Re: Instantaneous Communications plus Time Dilation Equals ???

Re: Instantaneous Communications plus Time Dilation Equals ???

Re: Instantaneous Communications plus Time Dilation Equals ??? Speculation is fun. This thread makes me want to catch up on the current state of this stuff.

Re: Instantaneous Communications plus Time Dilation Equals ??? Setting aside wormholes, I'm still curious about the interaction between time dilation and entangled particles. I know they've experimentally shown that entanglement transmits state FTL (granted the info isn't accessible FTL). Shouldn't it be possible to test the effects of multiple entanglement state changes under relativistic conditions? I'm not clear on how you verify state transferred via entanglement. Can you keep tweaking the same entangled pair over and over? Could you tweak one particle at a given frequency, move the other particle at relativistic speed, check it at the same frequency (time-dilated) and see if the results correlate? Or does that even have meaning with entanglement? I know QM doesn't much factor time into its equations. That's why I suspect, unlike a wormhole, an entanglement device wouldn't lock the two particles into a single frame of reference.

Re: Is "ether" real? I prefer to believe in the Truth Fairy, and of course Sanity Claus.

Re: Possible Future Salvage Yeah, pretty cool. Not rendered in the best medium here, but the storyline would be fun for a game.

Re: Instantaneous Communications plus Time Dilation Equals ??? I surrender. At this point, reviewing the thread, I have to conclude that you understand what we're saying, but you don't want to accept it. That's fine. Let me just say that special relativity is not a matter of perception or personal philosophy or even common sense. It's a scientific framework that has been challenged, and confirmed, over the course of a hundred years by lots of very smart people who are fully aware of how crazy it sounds. I urge you to research it further using whatever scientific sources you trust. Hopefully it'll click one day, because it's pretty cool, mind-expanding stuff.

Re: Instantaneous Communications plus Time Dilation Equals ??? Think of it as akin to the Doppler effect. If I'm on the train, the pitch of the horn is constant. If I'm on the platform, the pitch of the horn changes as it passes. Question: What's the pitch of the horn? Answer: It depends on your frame of reference. Is that two different actual realities of the same event? No, it's one reality as it affects two different frames of reference. The "reality" is the horn vibrates the air at a certain frequency in its reference frame. Its effect changes in different reference frames. Same with the simultaneity scenario. The reality is "two beams of light are emitted in opposite directions in the train car." The effect changes in different reference frames. Anyway.

Re: Instantaneous Communications plus Time Dilation Equals ??? That's the weird thing. It's not an optical illusion. It is reality. That's where the time dilation comes from. The reason the engineer sees the light beam moving away from the train faster than I do is because time is moving slower for the engineer. Time is moving much slower for the rocket camera, due to its speed. (Incidentally we tend to simplify the thought experiments by anthropomorphizing them with humans, cameras, etc. But when I say "observer," I don't mean there has to be some intelligence or perception mechanism. Anything that has any kind of contact with the object can be called an "observer.")

Re: Instantaneous Communications plus Time Dilation Equals ??? The point is, they're not mutually exclusive. Consider the headlight-on-a-train analogy. I'm standing on the platform as the train goes by. It switches on its headlight. What I see is the beam of light moving forward at c. I also see the train moving in the same direction at a lower speed v. To me, the beam of light is pulling away from the train at a speed of c-v. The train engineer looks out his window when he switches on the headlight. What he sees is the beam of light moving away at c. Not c-v, but c because the speed of light is constant in all frames of reference. Is the train moving in relation to the photons? When the engineer switches on the headlight, he also fires a rubber science rocket-camera mounted on the front of the train. The camera travels at a speed infintesimally close to c. From the platform, I see the beam of light moving away from the projectile at some infintesimal speed. The camera sees the beam of light moving away at c. Is the camera moving in relation to the photons?

Re: Instantaneous Communications plus Time Dilation Equals ??? Light is a freaky thing. It moves faster than anything else can. It behaves according to observations that haven't been made yet. It always travels at the same speed to any observer, regardless of anything else going on. That last one is the key here. It really does matter who's watching. There's no absolute frame of reference. That's why it's called relativity. I'm not sure how many other ways we can phrase this. If you want crunchier explanations, there are plenty of books that lay out the math as detailed as you want to get. It may seem less crazy with graphical aids we don't have in this text environment.

Re: Is "ether" real? Seriously?

Re: Instantaneous Communications plus Time Dilation Equals ??? The two aren't mutually exclusive. It seems like they should be, but they're not. The universe allows "they hit at the same time" and "they hit sequentially" to both exist. Luckily the universe is kind enough to throw time dilation into the mix, so even though simultaneity doesn't mean what we think it should, causality is not violated. You can't exploit the lack of simultaneity to, say, see what's going to happen before it happens. Until you throw wormholes into the mix. Then you get the freak show we're discussing in this thread.

Re: Instantaneous Communications plus Time Dilation Equals ??? Right, "simultaneous" only has meaning in one inertial frame of reference. The concept of "simultaneous" seems universal to us because on Earth, we all effectively occupy the same inertial frame of reference. (We don't really, but the delta-v between reference frames on Earth is so small compared to relativistic speeds that the differences are negligible. At least until you talk about syncing digital signals from satellites.) Common sense didn't evolve to handle this weird crap. You have to rely on the math.

Re: Instantaneous Communications plus Time Dilation Equals ??? That's the crux of special relativity, though. Both frames of reference are equally valid and the speed of light is constant in both. All the time dilation weirdness emerges from that. It's extremely counterintuitive, but it's real.

Re: Instantaneous Communications plus Time Dilation Equals ???

Re: Instantaneous Communications plus Time Dilation Equals ??? Which works out to time running faster at A than at B. So people on the ship look through the wormhole and see people on Earth moving 100x faster. People on Earth see the ship's time moving 100x slower. That way 25 years can pass on Earth, 3 months can pass on the ship, and the collapse happens simultaneously for both sides. That's the scenario I proposed upthread. I think it'd be playable, though it doesn't match the real-world physics. (If you don't have time running at two different speeds, you get a non-simultaneous collapse, which again gives you time travel/causality issues.)

Re: Instantaneous Communications plus Time Dilation Equals ??? So let's say Gate A gets destroyed in 2052. When Gate B arrives in 2150, Gate A hasn't existed on Earth for 98 years. What does Gate B connect to? Or is there a point at which the people on the spaceship looked through the wormhole and saw Gate A disappear?

Re: Instantaneous Communications plus Time Dilation Equals ???

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Re: Instantaneous Communications plus Time Dilation Equals ??? Incidentally, the FAQ that Nyrath linked to addresses bringing a wormhole into another wormhole: Short answer: a tiny communicator-wormhole should pass through a big spaceship-wormhole without incident. Though the convolutions regarding time dilation boggle the mind.