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# help I dont understand relativity

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a island Registered User regular
I failed uni physics 101 cause electricity and angular momentum is absurd

What do you means it's conserved I thought that wasn't a thing but it is!??

I was good at calc and math till it got weird with Euclid and three dimension calc.got fucking weird

And linear algebra, and proofs

Actually what's y'all's fave math proof

The square root of two is fun but my fave is the limit proof of the undefined zero, and mostly cause it makes the lol devise by zero jokes old

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Registered User regular
The one internal explanation for something my brain put together which I don't know if it's actually accurate but which made sense to me and helps me contextualize things is the whole "as we observe a reference window moving faster time is slower in it" coupled with space and time being the same thing.

Everything in the universe is always moving the same amount always. Space is on one axis, time is on the other, and the rate at which everything is moving is basically a circle - on one end (time) an object is stationary relative to you, and 100% of its movement is in time. On the other end (space) something is moving at c, and appears to be ageless (photons). Energy to move "faster" in space (closer to c) is expended and moves you away from time, and mass determines the amount of energy it takes.

I dunno, it makes sense to me (even if the "circle" description isn't accurate).

Also my mind exploded when I realized that since they move at c, from the reference window of photons they should be created and annihilated in two places at the same time.

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Registered User regular
Jragghen wrote: »
Also my mind exploded when I realized that since they move at c, from the reference window of photons they should be created and annihilated in two places at the same time.

I think about this a lot! Here's a draft from when we were on page 1 that i was too scared to post:

I spend a lot of time thinking about how photons don't actually experience time from their perspective.

To them, they are just everywhere they ever will be all at once from the instant they are created. More like an nth dimensional string that just suddenly exists across spacetime and then just as suddenly stops. It's only our perspective that makes them seem like discrete things moving around.

Really fucks with ya

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a island Registered User regular
edited July 2021
Jragghen wrote: »
Also my mind exploded when I realized that since they move at c, from the reference window of photons they should be created and annihilated in two places at the same time.

I think about this a lot! Here's a draft from when we were on page 1 that i was too scared to post:

I spend a lot of time thinking about how photons don't actually experience time from their perspective.

To them, they are just everywhere they ever will be all at once from the instant they are created. More like an nth dimensional string that just suddenly exists across spacetime and then just as suddenly stops. It's only our perspective that makes them seem like discrete things moving around.

Really fucks with ya

? Photons aren't every where at once.in a general sense they are but a individual a photon is ejected and refracted and reflected and etc and we obsevre the result of that

Photographs are literal time captures of light

The Cow King on
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might be real Registered User regular
photons are moving at the speed of causality though, so they (subjectively) would not experience time, even though from the outside that’s not the case.

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Who are you? What do you want?Registered User regular
C speed ideas don't have perspective

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Who are you? What do you want?Registered User regular
C speed ideas are all like no perspective only zoom

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It looks like a harmless old computer, doesn't it? Left in this cave to rot ... or to flower!Registered User regular
Relativity is easy, Gödel’s incompleteness theorem is the one you wanna watch out for if you don’t wanna lose sleep

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Registered User regular
The speed of light is in the eye of the beholder.

Whippy wrote: »
nope nope nope nope abort abort talk about anime
I like to ART
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J. Duggan Esq. Wrestler at LawRegistered User regular
This shit makes my head hurt.

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Registered User regular
Doodmann wrote: »
The speed of light is in the eye of the beholder.

Why would it be in a classic crpg

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Registered User regular
i mostly like learning just enough about physics to know exactly how to best piss off my nerd friends when talking about it

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Registered User regular
Wait did stargate actually teach me something about physics cause relative time doesn't seem all that difficult to grasp. Ships moving near the speed of light? Time for and inside and the ship is slower than time outside the ship. Oh you're in a massive gravity well, time moves slower for you than people just outside the gravity well.

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Do you have enemies then? Good. That means you’ve stood up for something, sometime in your life.Registered User regular
Ok so lets talk about some history.

The nature of light was actually a hotly contended thing. Newton and Gallieo argued pretty hard that it was a particle. But continual research in the 1700’s made the majority of physicists believe that it was a wave (it’s both, but who cares). The fact that it was a wave created a whole bunch of problems.

Key of which is that it need a medium to flow through. Scientists thought it existed in the aether. They made aether up and started looking for it. Shockingly they didn’t succeed! They tried measuring the speed of light at noon and midnight, and they did the same thing six months later when the earth was on the other side of the sun. They were expecting that with the velocity of the earth adding speed onto things they would get variance of like forty percent. Shockingly they didn’t! Their variance was like ten percent, which I think was pretty impressive at the time.

So scientists came to the uncomfortable idea that the speed of light was for some reason 2.99x10^8m/s no matter how you measured it. This was not as per the current idea of Galilean physics which had the very sensible idea that that if you are travelling at 20m/s and throw a ball at ten 10m/s to an outside observer it would appear the ball went 30m/s. The speed of light caused Serious Problems, because it created the eternal joke of, if you are travelling at the speed of light and turn the lights on what happens? Galilean physics can’t answer that question.

So Einstein showed up and fixed everything with two ideas. His first postulate was that no matter the observer the speed of light in a vacuum doesn’t change, as per the research. The second one is that there is no One True Reference frame and the laws of physics are just as valid no matter the reference frame.

Einstein also solved the problem of the aether by going back to the idea that light was a particle so it doesn’t need a medium. DeBrogile eventually proposed the idea that light actual has dual particle wave properties.

Let’s just pause and talk about reference frames. Einstein asked the question, are you moving? And he came up with the answer of no. Smart alecs will pipe up and say you’re moving around the Sun. Einstein argued that according to you, you are stationary, and it’s the sun that is moving. Similarly, if someone was in a car, going at a steady pace, they don’t feel any acceleration, so for all they know it’s actually the earth that is moving past him. A reference plane is basically how you refer to two seperate objects (it can be many objects say a train and everything on it) one travelling at one speed and another being stationary (according to them). But the important thing to think about is, to you, your reference plane is absolute and everything you see does happen.

So we can combine Einstein’s postulates and see what shakes out. Imagine a ship is travelling across space and they’ve got a big window so you as an outside observer back on earth can watch what is going on. On that ship there is a clock that keeps time. It’s fancy, they way it keeps time is that it bounces between two mirrors. To people on the ship moving through space, they just watch the light go up and down in a straight line forever at the speed of light.

Not for you though, you’re watching this photon of light (yes, you do have good eyes) and to you, since the ship is in a different reference plane (that is travelling say from your left to your right), you see the light go up and down but it’s also travelling left to right as well so to you, the photon looks like this /\/\/\/\/\ it’s moving at a diagonal to you.

This means, in your reference plane the light has further to travel compared to the observation on the ship, on the ship it only has to up and down, but to you it’s travelling that up and down part and the left to right part as well. To you there is a physical increase in the distance travelled. But the speed of light is the same in both situations which means as you watch it, it takes longer for that light to get from one side of the mirror to the other since it has further to travel. The events still happen on the ship but things change. The Implications for this is that events on the ship still happen, but for you they are dilated and take longer to happen. The events of the ship appear to happen slower.

The reverse will also happen to them as well, to them, you are moving by and they are staying still, and if you had a light clock they would see your light clock go /\/\/\ as well, and to them your light has further to travel and your events to them would appear to move slower.

We can measure this in real life. Muons are a fundamental particle of the universe that travel 99.9% the speed of light and have a half life of 2.2us (that should be mu, by I can’t find that character on my phone) multiplying those numbers together, they should only be able to travel 650m or so before they decay. This happens around 15km up in the atmosphere, so you would expect an absolute minimal amount of muons to hit the earth, but they’re everywhere, you can get a muon detector and there is a drop a in their numbers but they are easily measurable.

So what’s going on? At 99.9%c the Lorentz factor (the amount time slows down) is around 22 so when we observe the muons hurtling towards us, we observe their decay to be 22 times slower, so instead of covering 650m they cover closer to 14kms allowing way more muons to reach the surface of the earth.

Disclaimer, I’ve had several beers. I either remembered everything or calculated it in my head, my math may be out.

But that’s pretty much time dilation in special relativity.

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Registered User regular
Doodmann wrote: »
The speed of light is in the eye of the beholder.

Why would it be in a classic crpg

It’s part of the solution to a puzzle on the second drow level.

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Do you have enemies then? Good. That means you’ve stood up for something, sometime in your life.Registered User regular
Sleep wrote: »
Wait did stargate actually teach me something about physics cause relative time doesn't seem all that difficult to grasp. Ships moving near the speed of light? Time for and inside and the ship is slower than time outside the ship. Oh you're in a massive gravity well, time moves slower for you than people just outside the gravity well.

The gravity one is correct.

The time outside the ship isn’t that correct.

If you observe the ship the events in the ship it will appear like they are moving slower, however observers on the ship will see the other people move slower.

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Registered User regular
Blake T wrote: »
Ok so lets talk about some history.

The nature of light was actually a hotly contended thing. Newton and Gallieo argued pretty hard that it was a particle. But continual research in the 1700’s made the majority of physicists believe that it was a wave (it’s both, but who cares). The fact that it was a wave created a whole bunch of problems.

Key of which is that it need a medium to flow through. Scientists thought it existed in the aether. They made aether up and started looking for it. Shockingly they didn’t succeed! They tried measuring the speed of light at noon and midnight, and they did the same thing six months later when the earth was on the other side of the sun. They were expecting that with the velocity of the earth adding speed onto things they would get variance of like forty percent. Shockingly they didn’t! Their variance was like ten percent, which I think was pretty impressive at the time.

So scientists came to the uncomfortable idea that the speed of light was for some reason 2.99x10^8m/s no matter how you measured it. This was not as per the current idea of Galilean physics which had the very sensible idea that that if you are travelling at 20m/s and throw a ball at ten 10m/s to an outside observer it would appear the ball went 30m/s. The speed of light caused Serious Problems, because it created the eternal joke of, if you are travelling at the speed of light and turn the lights on what happens? Galilean physics can’t answer that question.

So Einstein showed up and fixed everything with two ideas. His first postulate was that no matter the observer the speed of light in a vacuum doesn’t change, as per the research. The second one is that there is no One True Reference frame and the laws of physics are just as valid no matter the reference frame.

Einstein also solved the problem of the aether by going back to the idea that light was a particle so it doesn’t need a medium. DeBrogile eventually proposed the idea that light actual has dual particle wave properties.

Let’s just pause and talk about reference frames. Einstein asked the question, are you moving? And he came up with the answer of no. Smart alecs will pipe up and say you’re moving around the Sun. Einstein argued that according to you, you are stationary, and it’s the sun that is moving. Similarly, if someone was in a car, going at a steady pace, they don’t feel any acceleration, so for all they know it’s actually the earth that is moving past him. A reference plane is basically how you refer to two seperate objects (it can be many objects say a train and everything on it) one travelling at one speed and another being stationary (according to them). But the important thing to think about is, to you, your reference plane is absolute and everything you see does happen.

So we can combine Einstein’s postulates and see what shakes out. Imagine a ship is travelling across space and they’ve got a big window so you as an outside observer back on earth can watch what is going on. On that ship there is a clock that keeps time. It’s fancy, they way it keeps time is that it bounces between two mirrors. To people on the ship moving through space, they just watch the light go up and down in a straight line forever at the speed of light.

Not for you though, you’re watching this photon of light (yes, you do have good eyes) and to you, since the ship is in a different reference plane (that is travelling say from your left to your right), you see the light go up and down but it’s also travelling left to right as well so to you, the photon looks like this /\/\/\/\/\ it’s moving at a diagonal to you.

This means, in your reference plane the light has further to travel compared to the observation on the ship, on the ship it only has to up and down, but to you it’s travelling that up and down part and the left to right part as well. To you there is a physical increase in the distance travelled. But the speed of light is the same in both situations which means as you watch it, it takes longer for that light to get from one side of the mirror to the other since it has further to travel. The events still happen on the ship but things change. The Implications for this is that events on the ship still happen, but for you they are dilated and take longer to happen. The events of the ship appear to happen slower.

The reverse will also happen to them as well, to them, you are moving by and they are staying still, and if you had a light clock they would see your light clock go /\/\/\ as well, and to them your light has further to travel and your events to them would appear to move slower.

We can measure this in real life. Muons are a fundamental particle of the universe that travel 99.9% the speed of light and have a half life of 2.2us (that should be mu, by I can’t find that character on my phone) multiplying those numbers together, they should only be able to travel 650m or so before they decay. This happens around 15km up in the atmosphere, so you would expect an absolute minimal amount of muons to hit the earth, but they’re everywhere, you can get a muon detector and there is a drop a in their numbers but they are easily measurable.

So what’s going on? At 99.9%c the Lorentz factor (the amount time slows down) is around 22 so when we observe the muons hurtling towards us, we observe their decay to be 22 times slower, so instead of covering 650m they cover closer to 14kms allowing way more muons to reach the surface of the earth.

Disclaimer, I’ve had several beers. I either remembered everything or calculated it in my head, my math may be out.

But that’s pretty much time dilation in special relativity.

Ok but what if I were inside the washing machine and Tef was watching me from NZ

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TURN THE BEAT BACK InternetModerator Mod Emeritus
help I don't understand my relatives

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Registered User, Moderator mod
Why does time dilation make your experience of time passing diverge if both reference points equally validly see the other as the one accelerating, how do you end up with the 100 years passed back on earth when it was only 1 year for you situation?

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In the scuppers with the staggers and jagsRegistered User regular
edited July 2021
Knob wrote: »
help I don't understand my relatives

Finally, a chart in this thread I can actually follow.

Jedoc on
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Do you have enemies then? Good. That means you’ve stood up for something, sometime in your life.Registered User regular
edited July 2021
Why does time dilation make your experience of time passing diverge if both reference points equally validly see the other as the one accelerating, how do you end up with the 100 years passed back on earth when it was only 1 year for you situation?

Ok, this is the hard part of special relativity. It’s genuinely difficult and most people explain it using true physics concepts that are poorly described.

Most people try and describe it using general relativity which has harder maths but has someone attainable concepts. General relativity says that mass warps space time (this is how we get gravity) learning to time dilation, or that acceleration through an inertial change will lead to time dilation. Both of these are true but you can set up situations where neither of these apply, so while they may contribute to time dilation, these aren’t the main reason why we can have objects experience more time than others.

The math involved for this one is actually a bit. But the key thing to realise is that “true” time dilation occurs for stationary objects. An object that moves away from you and returns in terms of reference planes is clearly not in terms of their reference stationary. Because the traveler of the ship sees objects externally go one way, and then the other

If you are comfortable with time dilation then this is probably the best video I’ve found that addresses the twins paradox.

Blake T on
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Registered User regular
Jedoc wrote: »
Knob wrote: »
help I don't understand my relatives

Finally, a chart in this thread I can actually follow.

Which of these boxes can fuck

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In the scuppers with the staggers and jagsRegistered User regular
Depends on what state you're in and how far your time machine went, I reckon.

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Do you have enemies then? Good. That means you’ve stood up for something, sometime in your life.Registered User regular
Jedoc wrote: »
Knob wrote: »
help I don't understand my relatives

Finally, a chart in this thread I can actually follow.

Which of these boxes can fuck

I mean there is evidence for fucking in every box other than the lowest boxes.

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Definitely not a banana Registered User regular
Machwing wrote: »
Relativity is easy, Gödel’s incompleteness theorem is the one you wanna watch out for if you don’t wanna lose sleep

Ctrl+c

Ctrl+v into browser

Open Wikipedia article

Wikipedia is too complicated, select Simple English version

Simple English version is too complicated, close browser, blame reality

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Registered User regular
What’s the furthest box any of us have met

I go 5 right and 2 up

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Registered User regular
Quid wrote: »
Machwing wrote: »
Relativity is easy, Gödel’s incompleteness theorem is the one you wanna watch out for if you don’t wanna lose sleep

Ctrl+c

Ctrl+v into browser

Open Wikipedia article

Wikipedia is too complicated, select Simple English version

Simple English version is too complicated, close browser, blame reality

Wait, I read this book. It's something to do with an ant named aunt.

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Registered User regular
Jragghen wrote: »
Also my mind exploded when I realized that since they move at c, from the reference window of photons they should be created and annihilated in two places at the same time.

I think about this a lot! Here's a draft from when we were on page 1 that i was too scared to post:

I spend a lot of time thinking about how photons don't actually experience time from their perspective.

To them, they are just everywhere they ever will be all at once from the instant they are created. More like an nth dimensional string that just suddenly exists across spacetime and then just as suddenly stops. It's only our perspective that makes them seem like discrete things moving around.

Really fucks with ya

? Photons aren't every where at once.in a general sense they are but a individual a photon is ejected and refracted and reflected and etc and we obsevre the result of that

Photographs are literal time captures of light

I think you misread what I wrote

I didnt say they are everywhere at once, I said they are everywhere they ever will be at once...from their perspective. Since they "experience" no time moving at c, they are at once at their point of creation and destruction, plus every point along the path they take to get there. Like a string.

I definitely could have worded it better. Or someone could have, maybe not me.

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Registered User regular
We all move at the Speed of Light 11:57

I think this video actually made me understand a bit more in my feeble mind about space time

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Yeah ZestRegistered User regular
Okay so now that we've all solved the speed of light, can we focus on the speed of heavy?

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Registered User regular
Or the speed of dark

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a wit so dry it shits sandRegistered User regular
it's people you share a bloodline with

"I am not young enough to know everything." - Oscar Wilde
Real strong, facetious.

Steam: Chagrin LoL: Bonhomie
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No face Registered User regular
Pinfeldorf wrote: »
Okay so now that we've all solved the speed of light, can we focus on the speed of heavy?

RED or BLU?

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In the scuppers with the staggers and jagsRegistered User regular
I've read a bunch of popular physics books in my time, and it always sort of makes sense to me while I'm reading it but I immediately forget everything but the most dumbed-down examples, like the clock in a satellite.

I accept that it probably all checks out once you do the math, and I have no choice but to hope that the nerds who understand this stuff use the knowledge for good. Aside from nuclear weapons, which they already kinda let out of the bag as far as cats go.

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Registered User regular
facetious wrote: »
it's people you share a bloodline with

Poor Alucard

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No face Registered User regular
Or the speed of dark

The Speed of Dark is directly linked in proportion to the Speed of Protagonist. If the Protagonist moves quickly then Dark will also move quickly, always being just ahead no matter how fast Protagonist moves. Conversely, if Protagonist is slow then Dark will also be slow while still maintaining the same distance. This ensures that Dark will always make contact with Plot Particles first and Protagonist will arrive shortly after, a phenomena related to the Nick of Time.

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It looks like a harmless old computer, doesn't it? Left in this cave to rot ... or to flower!Registered User regular
Quid wrote: »
Machwing wrote: »
Relativity is easy, Gödel’s incompleteness theorem is the one you wanna watch out for if you don’t wanna lose sleep

Ctrl+c

Ctrl+v into browser

Open Wikipedia article

Wikipedia is too complicated, select Simple English version

Simple English version is too complicated, close browser, blame reality

“There are unprovable truths” is more or less the summary

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I will build a labyrinth to house the cheese Registered User regular
I think math gets up to more esoteric shit than other sciences because a lot of it fundamentally can't be meaningfully tested by experiment. Which isn't a dig at all, you just don't get the same odd stuff in e.g. biology because it's based on observable phenomena, so you're always starting from the safe bedrock of "this thing definitely happens and we can see it happen." Math often doesn't have (and often can't have, really) that grounding so things sometimes get weird.

Although I'm still angry about the time I learned about the workaround set theorists came up with for the seeming paradox of the set of all sets that do not contain themselves in order to avoid accidentally blowing up set theory. Y'all fuckers cheated and you know it.

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Sleepy Registered User regular
Machwing wrote: »
Quid wrote: »
Machwing wrote: »
Relativity is easy, Gödel’s incompleteness theorem is the one you wanna watch out for if you don’t wanna lose sleep

Ctrl+c

Ctrl+v into browser

Open Wikipedia article

Wikipedia is too complicated, select Simple English version

Simple English version is too complicated, close browser, blame reality

“There are unprovable truths” is more or less the summary

The frustrating part is that physics meets the criteria for the theorem to apply.

Steam: Polaritie
3DS: 0473-8507-2652
Switch: SW-5185-4991-5118
PSN: AbEntropy
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I will build a labyrinth to house the cheese Registered User regular
Zeno's Paradox is also theoretetically rigorous, but provably false in the real world.