Dumb Question about flying at lightspeed

Eventually you'll get down to geometry. And you can ask 'why' for that, again, but this time there's a decent answer: "While it didn't have to work that way, having a time dimension that's just like a space dimension would mean there's no preferred direction of time. For (complicated reasons), this makes life unlikely to ever appear."
That's an odd way of putting it, especially given the Galilean option, while in STR any timelike direction is as good as any other. What distinguished the Euclidean one is is inconsistent with causality due to not distinguishing space and time, which is I think what you're trying to get at. This is a question allowing a consistent ordering of events rather than a preferred direction. You can turn around in Euclidean space, but not in time.

But you're correct in that there is a sense in which there are three simplest geometries: {Euclidean, Galilean, Minkowski}, of which the first is inconsistent with causality while the second has a degenerate metric: temporal and spatial measurements are disconnected from each other. So in a way the STR case is the most well-behaved geometry out of the three simplest cases. One technical characterisation of the specific sense in which those are simplest geometries is: isotropy of space, homogeneity of time, and inertial frames forming a group.
 
That's an odd way of putting it, especially given the Galilean option, while in STR any timelike direction is as good as any other. What distinguished the Euclidean one is is inconsistent with causality due to not distinguishing space and time, which is I think what you're trying to get at. This is a question allowing a consistent ordering of events rather than a preferred direction. You can turn around in Euclidean space, but not in time.

But you're correct in that there is a sense in which there are three simplest geometries: {Euclidean, Galilean, Minkowski}, of which the first is inconsistent with causality while the second has a degenerate metric: temporal and spatial measurements are disconnected from each other. So in a way the STR case is the most well-behaved geometry out of the three simplest cases. One technical characterisation of the specific sense in which those are simplest geometries is: isotropy of space, homogeneity of time, and inertial frames forming a group.
Pretty much. I'm trying to inculcate an intuition for this in people who haven't studied relativity for years, and I'm not sure how well I'm doing; I inevitably have to skip parts that can be picked apart.

I don't think Galilean space-time would be the least bit incompatible with life, but there is at least a sense in which a universe running on those rules would be more complicated. And even if it's not, 50/50 odds are better than 33/66. Though in the end, some of our physics might very well be down to chance, with other universes that have different laws existing in math-space.
 
Reading a physics for dummies book (the one by brian greene, I don't have it handy so i dont recall the title) anyway he talks about why you can never match the speed of light and it is making no sense at all to me.
It occurs to me that, if you're reading a book on the subject, that book probably uses the point that "light has the same speed relative to all observers" to then go on to explain the concepts of time dilation, etc.

In that light, it might be that the problem you're having is that you're viewing the invariance of the speed of light as something like a postulate in math -- something fundamental from which additional principles are derived. Although the math of special relativity does use the invariance of the speed of light as a postulate to derive the equations of motion, etc., it might be more fruitful to view the invariance of the speed of light as an observation, and the derivation of the rules of Special Relativity as an attempt to figure out what underlying rules would cause that observation to be the case.

At the first layer, you figure out that time dilation, length contraction, and relativity of simultaneity have to be things. Those effects, combined, are what cause all observers to measure a beam of light as traveling the same speed relative to themselves. However, that still leaves the question of why those effects exist and why they happen to line up in such a way that they cause then invariance of the speed light.

Investigating that question is what leads to the understanding that space and time are different slices of a single whole (creatively named "spacetime") and that the rules of relativity are manifestations of the rules of geometry in this larger spacetime.
 
NOTE: There are some solutions for general relativity that allow you to reach other stars in much less time than an unaided beam of light. However, in all cases it is important to note that you are NOT in fact traveling Faster Than Light. Instead, you are either:

1: Taking a shortcut (example: Wormholes, Krasnikov Tubes)

or

2: Bashing spacetime with an Exotic Matter hammer until the bits of reality around your ship get moving where you want them to go, bringing you along for the ride. (example: Alcubierre Drive and related metrics)
 
We live in a four-dimensional universe, where time is one of the dimensions. It's not that your momentum is a three-dimensional vector, which has a maximum size; it's that your momentum is a four-dimensional direction (unit vector), which only has so many angles to choose from.

SO WE WERE 4TH DIMENSIONAL BEINGS ALL ALONG!?
 
People talking about the speed of light being constant.
Bugs me.
why?
Light has been stopped.
Thus stating that the speed of light as a constant that we can use is simply another lie we tell ourselves so we don't cry whenever we think about 'fast'
Further more the "speed of light", is simply the motion of light in a vacuum, from our perspective.
SO WE WERE 4TH DIMENSIONAL BEINGS ALL ALONG!?
The level of being we are is constrained to only the levels of dimensions we can interact with.
The word knowingly is not needed.
 
'Is Light Matter?'

Edit:
Article:
As per physics, relativity is everywhere and as per mathematicians symmetry is everywhere. As per Schrodinger's cat theory everything is probable not exact. So these leads to a virtual belief in the existence of parallel universe concepts or the existence of us somewhere far in time and space and along with us.
Right.

The article does seem to be nonsense. I actually wrote up a denouncement earlier, but I'm not completely convinced this isn't simply (very) poor translation. VIT university exists, and is apparently a good one; OTOH, I can't find any references to Souvik Mukherjee on their website. On the gripping hand, I couldn't find a list of professors there at all.

On the... fourth(?) hand... on the right foot. On the right foot, simply being a professor at a university doesn't mean you can't have plainly wrong opinions, even if a physics profressor really shouldn't be this wrong.

What's for certain is that there's nothing to learn here. @SpeckofStardust, you should try your best to forget everything you read on that page. It's either nonsense, or might as well be.
 
Because thinking about things hurts.
After all vacuum- a space entirely devoid of matter. -
Light it :turian:"technically":turian: quantum matter, (fun reads)
And thus because light is passing though it the area is no longer a vacuum.
(thinking hurts, and everything I have said may be wrong)
The "vacuum" in that quote is an idealized vacuum, and thus how things play out in practice does not really effect the validity of the statement. Beyond that, light does not typically interact with itself. Photons will pass straight through each other without anything really happening (most of the time, at any rate).
 
The thing with "the speed of light" is that it's actually more like there's a "maximum possible speed" constant and that's what light and any other massless things travel at, and for legacy reasons we're stuck with "the speed of light" as a label for it.
 
^ That.

It's really just a unit conversion. Like, we have a meterstick that's marked in meters when you lay it flat north-south, but it shows distance in light-nanoseconds if you lay it east-west... or rather, past-future.

Time and space may look different at first glance, but meters and seconds are both units of distance. It's just that a 'second' is a much, much larger unit than a 'meter'.
 
The thing with "the speed of light" is that it's actually more like there's a "maximum possible speed" constant and that's what light and any other massless things travel at, and for legacy reasons we're stuck with "the speed of light" as a label for it.

A better name would probably be 'speed of causality'.
 
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