Theory of Relativity?

[Mktavish]

but ya I see the only way here is to hang out with the gun nuts.

 

Tucker carelson should shut his pie hole

[Mudran]

So basically travelling in time is from some rotating centre (like black hole) to outside - if you could move the centre, there would be no time. And, yes I have no idea what theory of relativity is and yes, I tried to read about it.

Edited June 26, 2019 by Mudran

[NeedSomeMCP]

No problems; relativity is fairly complicated stuff to understand.

So, relativity says that time slows down the faster you go. Relativity also says that it is impossible for anything with mass to travel faster than the speed of light in a vacuum. If you were to plug in speeds faster than the speed of light into relativity equations, you would end up with time going backwards from your perspective. This would be impossible to achieve based on our current understanding because it would require an infinite amount of energy.

As for black holes, I don't know. I've never fiddled around with the equations for general relativity. I've heard some interesting ideas, like there is a hypothetical class of black hole where the cross through the event horizon would be somewhat survivable, but ends up with you being trapped in another space that is trapped by the black hole.

Here's a video that talks about some pretty cool physics stuff like wormholes and black holes and such.

[Mudran]

Thanks the author has a lot of interesting videos. But sadly nothing about theory of relativity.

I tried to watch other videos, but those arguments didn't make sense for me.

I would understand from videos of that author the time in blackhole or any gravitation object bends a timeline to curve as a capsule, where something else can happen if you take the longer curve around, but if you go straight line, you experience less time but nothing about accelerated speed. Accelerated speed is there only relevant to the speed of light, but all the explanations look relevant only to other observer and not general time.

It looks like in space - the time is speed of light, which is the speed of information about something happening somewhere. And according to that author cosmos is expanding equally for everyone, that means you don't see anything moving in time if it is moving from you, but still what if there is some "general time" from some other perspective we don't have?

Edited June 29, 2019 by Mudran

[NeedSomeMCP]

The video does talk about some of the things about relativity. Whenever it talks about spacetime, curved space, time dilation, etc., it is talking about relativity. And no worries, relativity is very non intuitive and difficult to wrap the mind around.

Gravity bends spacetime. In general relativity, space and time are treated together as a single entity called spacetime, and it is this spacetime that curves due to gravity. Being that everything has gravity, even people, you could say that spacetime curves around you or me, although the effect is so small on that scale that you wouldn't notice it. Around massive objects like a star or black hole, the effect is much more pronounced. The usual analogy is to take a blanket held at each corner and drop a bowling ball on it. The blanket represents spacetime and the bowling ball represents an object with a lot off mass that is bending the spacetime around it. Now imagine trying to drop an RC car onto that blanket and have it go through straight and come out the other end straight. It would be difficult, as any slight angle in your setup of the car would cause it to bend around the folds of the blanket. The car represents light in this case.

Speed is measured in distance traveled over time, or m/s. The denominator is time. If time is shrinking, the speed is increasing. This is a gross simplification, hopefully it helps.

With relativity, everything is relative with something else, and the relativity is linked by the underlying principle that the speed of light in a vacuum is constant and the same for every observer. In this physics theory, there would be no general time that can reference everything else. You could pick an arbitrary body, like the Earth, or the Sun, or the Milky Way's central black hole, Sagittarius A [not sure on my spelling for that one], and that could serve as a frame of reference, but that wouldn't be practical for describing the effects of high speed from most scenarios of interstellar travel. Tl;dr, relativity does not have a concept of general time. Everything is relative to everything else. By waving my arms in front of my face, I am creating relativistic distortions in space time between the rest of my body and my arms, although the effect is so small (because the speed is small and the gravity is small) that it is negligible in this case.

Yes, the speed of light is the maximum speed of information that can happen. Information can also be slower (like the biochemical processes resulting in our thoughts, or a sound powered telephone).

I'm not sure what you are getting at in your last part about the expansion of the universe.

[Fkemman11]

The video does talk about some of the things about relativity. Whenever it talks about spacetime, curved space, time dilation, etc., it is talking about relativity. And no worries, relativity is very non intuitive and difficult to wrap the mind around.

 

Gravity bends spacetime. In general relativity, space and time are treated together as a single entity called spacetime, and it is this spacetime that curves due to gravity. Being that everything has gravity, even people, you could say that spacetime curves around you or me, although the effect is so small on that scale that you wouldn't notice it. Around massive objects like a star or black hole, the effect is much more pronounced. The usual analogy is to take a blanket held at each corner and drop a bowling ball on it. The blanket represents spacetime and the bowling ball represents an object with a lot off mass that is bending the spacetime around it. Now imagine trying to drop an RC car onto that blanket and have it go through straight and come out the other end straight. It would be difficult, as any slight angle in your setup of the car would cause it to bend around the folds of the blanket. The car represents light in this case.

 

Speed is measured in distance traveled over time, or m/s. The denominator is time. If time is shrinking, the speed is increasing. This is a gross simplification, hopefully it helps.

 

With relativity, everything is relative with something else, and the relativity is linked by the underlying principle that the speed of light in a vacuum is constant and the same for every observer. In this physics theory, there would be no general time that can reference everything else. You could pick an arbitrary body, like the Earth, or the Sun, or the Milky Way's central black hole, Sagittarius A [not sure on my spelling for that one], and that could serve as a frame of reference, but that wouldn't be practical for describing the effects of high speed from most scenarios of interstellar travel. Tl;dr, relativity does not have a concept of general time. Everything is relative to everything else. By waving my arms in front of my face, I am creating relativistic distortions in space time between the rest of my body and my arms, although the effect is so small (because the speed is small and the gravity is small) that it is negligible in this case.

 

Yes, the speed of light is the maximum speed of information that can happen. Information can also be slower (like the biochemical processes resulting in our thoughts, or a sound powered telephone).

 

I'm not sure what you are getting at in your last part about the expansion of the universe.

So space is more like a fabric, huh. What the hell is space made out of I wonder. I mean it would have to be universal. Folding space was an interesting idea I read about in one of Frank Herbert's books. Knowing a set of coordinates here and calculating the coordinates of where you want to be. But I didn't understand the mechanics behind it. I don't think faster than light travel is possible, but a sort of teleportation seems very plausible. When you drive your car, are you moving or is everything else? :laugh:

[NeedSomeMCP]

Its easy to think of space as a kind of nothingness, and for most practical purposes, it is. I found this about 'empty' space, hopefully it helps:

 

 

 

Empty space wasn’t always so mystifying. Until the 1920s physicists viewed the vacuum much as the rest of us still do: as a featureless nothingness, a true void. That all changed with the birth of quantum mechanics. According to that theory, the space around a particle is filled with countless “virtual” particles rapidly bursting into and out of existence like an invisible fireworks display.

http://discovermagazine.com/2008/aug/18-nothingness-of-space-theory-of-everything

The idea of folding space is one of the driving thoughts behind the concept of a wormhole, which would, under some theories, allow faster than light travel. Similarly, an Alcubierre drive would separate the craft from the fabric of space time and allow the craft to travel at speeds faster than light. These are speculative ideas for now that are conceivable under relativity, but until they are actually done, that's all they are. I imagine if someone had an idea how to create these things, civilization would already be trying to build them.

I've heard of teleportation experiments, but they do not violate relativity. There are actually a couple things that can move faster than the speed of light in a vacuum - the expansion of space, and quantum entanglement being two of them. However, these things still do not allow the transfer of information at speeds faster than the speed of light in a vacuum.

Your last statement is a legitimate question, and the answer is that it is relative based on the perspective of the observer. From the cars perspective, everything around it is moving. From the perspective of a pedestrian bystander, your car is clearly moving. From the perspective of Jupiter, your car is rotating around the Sun.

[Fkemman11]

Cool! So does relativity basically mean that everything is moving relative to something else? But if everything moves relative to something else, then does that mean there is no center? Or would the center be something with the strongest gravitational field? Like does the sun move, or is it sort of a sovereign body that influences everything else within a certain distance from it? I wonder if there are currents in space (and time) the same as there are with the ocean?

 

What's most interesting to me is when scientists do finally start to experiment with something like teleportation, will they discover that there is actually something more to humans and animals than their matter? :wink:

[NeedSomeMCP]

Everything does move relative to something else in every physical model of the universe I am aware of. Relativity, in the sense of Theory of Relativity, means that space and time and the speed of light are all fundamentally linked together. In a sense, this means that if an object can observe something else moving, that the observing object has to be moving as well.

For centers, it depends on what you are looking at. If you are looking at the universe as a whole, some big brain might be able to figure out where the big bang happened and call that the center. Or, each point in the universe could be considered the center because everything is expanding away from each individual point [if I understand it correctly]. Looking at other systems, treating different objects as centers is quite intuitive. Like, if I were to be looking at the Milky Way galaxy, its central black hole, Sagittarius A, would be an intuitive thing to think about as center. Likewise with Jupiter and Jupiter's moons, or the Sun and our solar system, or the nucleus in the atom. Center even has specific connotations in various aspects of engineering [center of gravity, center of momentum, center of mass, etc.]. And with the sun and Sagittarius A, both those bodies happen to be the biggest gravitational bodies of those respective systems. For me, I use it to simplify problems. If I can define a center in such a way that the mathematics of the scenario is much simpler.

Take the center of the solar system for example. Today, we tend to look at the sun as the center of our solar system, in ancient days it was believed that the Earth was the center of the solar system. It is possible to describe all the bodies in the solar system as if Earth is the center, however, the mathematics and regions of space quickly become convoluted with all kinds of strange functions. Understanding the Sun as the center of the solar system greatly simplifies everything.

The sun and solar system as a whole move through space as well, as the Sun is in orbit around Sagittarius A.

Even though we think of space as being empty, it is not. There are different particles that zoom around in outer space. In the solar system, the sun ejects radiation outward called the solar wind, which could be though of as having a current. From outside the solar system, radiation is directed to come in. At a point called the heliopause, these two forces cancel each other out. That force coming in could be thought of as a current too. There's also ripples in spacetime called gravitational waves. They bear some similarities to ocean waves in some ways, but not in others.

Theoretically (from a Newtonian perspective), the gravitational force between two bodies still exists despite how far they are away from each other, but at some point it is so negligible to not be worth counting. So the Sun pulls on Sagittarius A a very tiny amount; not enough to consider for most purposes.

edit: Here's an article that talks briefly about real life teleportation experiments https://science.howstuffworks.com/science-vs-myth/everyday-myths/teleportation1.htm

[Mudran]

I have cold now, so I started to ponder (under influence of this thread) why am I feeling always worse in the evening and during night, so I developed a theory that sickness is actually influenced by fazes of Moon in conjunction with Black hole, which spreads dark energy into universe and during dusk it is being transmitted until down. Because everytime anyone shows pictures of dark hole I start to feel sick and dizy.