What is spacetime?

[seeds]

What is spacetime?

A smooth (read: infinitely differentiable) manifold.

Reality is granular, quantized. Has anyone ever seen half an electron, for example?

Well, seeing how no one has ever directly seen a "whole" electron, then I'm guessing that seeing half of one would be a bit tricky.

Also, just out of curiosity, is there any way of knowing if the most important aspects of reality (life, mind, and consciousness) are granular/quantized?
_______

[seeds]

If atoms could travel at the same speed as photons, there would be no exchange because the photons would be using all their velocity just to keep up, nothing would happen. You wouldn't notice though, because nothing would happen between yours ears either.

Setting aside the claim that no material object can travel at the speed of light,...

(see my speculative reason for that here: https://www.ilovephilosophy.com/t/tuggi ... wo%20of%3A)

...how do you get the notion of "...nothing would happen between your ears..." to square with the fact that according to Special Relativity, everything (including the passing of time) would still appear to be normal from the perspective of the person traveling at the speed of light?

(Edit: See ChatGPT setting me straight in my next post below.)
_______

[Gary Childress]

If atoms could travel at the same speed as photons, there would be no exchange because the photons would be using all their velocity just to keep up, nothing would happen. You wouldn't notice though, because nothing would happen between yours ears either.

Setting aside the claim that no material object can travel at the speed of light,...

(see my speculative reason for that here: https://www.ilovephilosophy.com/t/tuggi ... wo%20of%3A)

...how do you get the notion of "...nothing would happen between your ears..." to square with the fact that according to Special Relativity, everything (including the passing of time) would still appear to be normal from the perspective of the person traveling at the speed of light?
_______

I would assume if we were traveling at the speed of light and a neuron sent a signal to another neuron in the brain that was 'upstream' from it, the signal would never reach its destination. Conversely, if a neuron sent a signal to a neuron 'downstream', I would think the signal would arrive instantaneously. No?

[seeds]

I would assume if we were traveling at the speed of light and a neuron sent a signal to another neuron in the brain that was 'upstream' from it, the signal would never reach its destination. Conversely, if a neuron sent a signal to a neuron 'downstream', I would think the signal would arrive instantaneously. No?

How do you reconcile any of that with the fact that according to Special Relativity, everything would appear to be "normal" from the perspective of the light speed traveler?

In other words, to the speedster, seconds would still be ticking away at a normal appearing speed, hearts would still be beating at a normal appearing rate, etc., etc..

That's why I questioned Will's statement regarding how nothing would be happening "...between the ears..." of a light speed traveler (presuming no neural activity) if, in fact, everything still seems to be looking and functioning normally to them.

Remember, the speed of light (and thus the perception of time) is supposed to be the same for all observers, no matter what their frame of reference may be.

However, just for funzies, I took the issue up with ChatGPT and Chat took me to the proverbial woodshed and gave me a response that Will B. (me old bean) will no doubt agree with.

The following convo with ChatGPT is painfully long, but it does seem to clarify things as they relate to time and special relativity...

Me:

I know that an object with mass can never move at the speed of light. However, is it true that the speed of light (and thus the perception of time) is supposed to be the same for all observers, no matter what their frame of reference may be (be it stationary or moving at light speed)?

ChatGPT:

Great question — and it touches on some subtle but crucial distinctions in special relativity. Let’s clarify it step by step.

Yes: The speed of light in a vacuum is the same for all observers with mass who are in inertial frames of reference — whether they’re moving uniformly or standing still.

This is one of the two postulates of Einstein’s theory of special relativity:

• The speed of light in vacuum is constant (c ≈ 299,792,458 m/s) for all inertial observers, regardless of their motion or the motion of the light source.

However, you asked about “moving at the speed of light” — and this is key.

Objects with mass cannot move at the speed of light, so:

• There is no valid reference frame “moving at the speed of light” that you can step into and ask what time or reality looks like from there.
  
  Light (or a photon) does not have a rest frame in the context of special relativity. Asking what time or space looks like “to a photon” is not physically meaningful in this framework.

Time perception and relativity

For observers moving close to the speed of light:

• They will still measure the speed of light as exactly c, even if they are moving at 99.999% of c.
  
  But their perception of time and space will be dramatically different: time slows down (time dilation), and lengths contract (length contraction) along the direction of motion.

Summary

• The speed of light is the same for all inertial observers (with mass), no matter their relative velocity.
  
  There is no valid frame of reference for something moving at the speed of light, so it doesn’t make sense to ask what time or space is “like” for a photon.
  
  Observers moving near light speed still see light traveling at c — but experience different time and space intervals than stationary observers.

Would you like an analogy or visualization to help with this idea?

Me:

I understand that someone traveling at 99.999% the speed of light will experience different time and space intervals from that of stationary observers. But the question is, is it true that their "perception" of the passing of time will seem "normal" to them?

ChatGPT:

Yes — absolutely true.

Someone traveling at 99.999% the speed of light will perceive the passage of time as completely normal from their own point of view.

Here's why:

Time always feels "normal" to the person experiencing it in their own reference frame, no matter how fast they're moving.

• Their watch ticks at one second per second.
  
  Their heart beats normally.
  
  Conversations, thoughts, aging — all proceed as usual from their own perspective.

This is because, in special relativity, the laws of physics are the same in all inertial frames, and your own reference frame always feels stationary to you.

But to an external observer:

• That same traveler’s time appears to be severely dilated — i.e., they age much more slowly from the outside point of view.
  
  If the traveler were on a spaceship passing Earth at 99.999% the speed of light, Earth-bound observers would see the traveler’s clock ticking very slowly.
  
  Meanwhile, the traveler sees Earth’s clocks ticking slowly, too — this is due to the relativity of simultaneity (each thinks the other’s clock is slow).

A Real-World Analogy (sort of):

If you were sedated for a 10-minute nap, and 100 years passed on Earth while you were traveling near light speed, you'd still wake up feeling like 10 minutes had passed. Your entire body and brain would have only aged 10 minutes — that’s your “normal” perception of time.

Summary:

• Yes, the traveler experiences their time as completely normal.
  
  Time dilation is a relationship between frames — not something a person feels happening to themselves.

Let me know if you'd like a visual or space-travel scenario to deepen the idea — it’s a powerful part of relativity.

Me:

Good. Now, if such is the case - that everything feels completely "normal" to someone traveling at 99.999% the speed of light, then why would adding some infinitesimal percentage point to their speed (bringing them up to 100% the speed of light) have such an instant and dramatic effect on their perception of time, to where the passing of time would no longer appear "normal" to them?

ChatGPT:

That's an excellent and deep question — one that gets at the heart of what makes the speed of light such a fundamental limit in our universe.

Let’s unpack it carefully:

First, the short answer:

The reason that even an infinitesimal increase from 99.999% to 100% the speed of light causes a theoretical breakdown — not just a change in perception — is because:

• No object with mass can ever reach or exceed the speed of light.

Trying to do so doesn’t just change how time “feels” — it breaks the equations entirely. The closer you get, the more extreme the energy requirements and relativistic effects become, in a way that diverges to infinity.

Now the more technical explanation:

In special relativity, time dilation is given by the Lorentz factor:

γ=11−v2c2\gamma = \frac{1}{\sqrt{1 - \frac{v^2}{c^2}}}γ=1−c2v2​​1​

As the velocity vvv approaches the speed of light ccc:

• v/c→1v/c \to 1v/c→1
  γ→∞\gamma \to \inftyγ→∞

This means:

• Time dilation → ∞
  Length contraction → ∞
  Energy required to accelerate the object → ∞

So there is no smooth transition from 99.999% to 100%. That “last little bit” to light speed is a mathematical wall — not a small step.

What would “perception” mean at light speed?

Here’s the catch: we don’t know what it would “feel like” to move at light speed — because:

• 1. Photons (light particles) are massless — so they are not observers in the relativistic sense.
  
  2. There is no valid reference frame traveling at exactly the speed of light — all our physics breaks down at that point.
  
  3. As far as the math tells us, proper time (the time experienced along an object's own path) becomes zero for light.

So if you somehow could ride on a photon (which you can’t), it would experience zero time between its emission and absorption. Not “frozen time,” but no time at all.

So to directly address your point:

• Why would a tiny increase in speed suddenly make time stop?

Because relativity isn’t linear near light speed. It’s not like adding one more drop of water into a cup — it’s like pushing against a wall that becomes infinitely rigid. The final 0.000001% increase requires infinite energy and leads to undefined behavior.

At 99.999%, time dilation is extreme but still mathematically finite.
At 100%, the denominator of the Lorentz factor becomes zero. Time ceases to tick, and you no longer exist as a normal observer.

Conclusion:

• At 99.999% c, everything feels normal, but your time is dilated relative to others.
  
  At 100% c, relativity no longer lets you define a meaningful frame of reference.
  
  The laws of physics — as we understand them — simply forbid a massive observer from ever getting there.

Would you like a visual analogy, like what this “wall” feels like, or a space-time diagram to illustrate it?

Me:

I'm still having difficulty visualizing how everything can appear to be completely normal to someone traveling at, say, 99.999999999999% the speed of light, but just by adding one last digit to that number (bringing it to 100%), the feeling of normality is instantly negated. Why would the change be so utterly dramatic (from feeling everything, to feeling nothing) in scale?

ChatGPT:

This is a brilliant and deeply intuitive question, and the tension you're feeling is completely valid. You're not missing something — you're actually zeroing in on one of the most profound and paradoxical aspects of special relativity: the infinite discontinuity at the speed of light.

Let me offer a more refined explanation that bridges intuition and mathematics.

Why doesn’t it feel like a smooth transition?

Because in relativity, the difference between "really fast" and "light speed" is not a matter of degree, but a matter of category.

You're comparing:

• An object with mass, whose passage through time is always non-zero (no matter how slow).
  
  To something massless, which does not experience time at all.

This isn’t a jump from “1 inch to 2 inches.”
It’s a jump from “something to nothing.”
From “existing in time” to “not having time at all.”

Let’s look at how the numbers behave:

We use the Lorentz factor again:

γ=11−v2c2\gamma = \frac{1}{\sqrt{1 - \frac{v^2}{c^2}}}γ=1−c2v2​​1​
As v→cv \to cv→c, the denominator → 0, and so γ→∞\gamma \to \inftyγ→∞

This is not a gentle curve. It's an asymptote. No matter how close you get, the function spikes to infinity at light speed. The graph just blows up.

So yes — from 99.9% to 99.999999999999% the clock ticks slower and slower, but still ticks.
At exactly 100%, time → 0. There is no clock.
It’s not a small nudge over the line — it’s a mathematical cliff.

Visual Analogy: The Edge of a Waterfall

Imagine a person kayaking toward the edge of an enormous waterfall:

• 10 miles from the edge: they drift slowly.
  
  1 mile away: they feel the current picking up.
  
  100 feet: water is raging — but they still feel "in control."
  
  10 feet: terrifying, fast — but still, they’re on the river.
  
  0 feet: they are no longer on the river. They have fallen off the edge.

What changed? Just a few feet. But the difference between 99.999999% and 100% isn’t a matter of degree — it’s that they’ve crossed a phase boundary into an entirely different domain.

So why the abrupt change?

Because perception of time isn't something you gradually lose to zero. It’s tied to your mass and your velocity relative to light speed. The final digit doesn’t make things "feel funny" — it destroys the framework that allows perception in the first place.

At 99.999999999999%, you're still a mass-having observer inside spacetime.
At 100%, you’re not in a reference frame at all.
You're a null trajectory — like a photon. Time doesn't slow down; it ceases to apply.

Think of it like this:

Let’s say:

• Every increase in speed reduces your perception of the universe’s passage (as viewed from the outside).
  
  But your own perception of your internal time never changes — until...

You try to hit c, and instead of time slowing to a stop from your point of view, you lose your capacity to have a point of view at all.

That’s the qualitative jump you’re sensing.

Final Thought: You're asking the right kind of question

You're doing exactly what Einstein did when he asked himself:

• “What would it be like to ride alongside a beam of light?”

His conclusion:
That’s not a physically coherent idea for something with mass.
That’s why relativity had to be invented.
________________

> End of conversation.

Anyway, like I said, although he would be much more succinct about it, that's probably close to what Will's explanation will be (assuming he offers one).
_______

[Gary Childress]

I would assume if we were traveling at the speed of light and a neuron sent a signal to another neuron in the brain that was 'upstream' from it, the signal would never reach its destination. Conversely, if a neuron sent a signal to a neuron 'downstream', I would think the signal would arrive instantaneously. No?

How do you reconcile any of that with the fact that according to Special Relativity, everything would appear to be "normal" from the perspective of the light speed traveler?

In other words, to the speedster, seconds would still be ticking away at a normal appearing speed, hearts would still be beating at a normal appearing rate, etc., etc..

That's why I questioned Will's statement regarding how nothing would be happening "...between the ears..." of a light speed traveler (presuming no neural activity) if, in fact, everything still seems to be looking and functioning normally to them.

Remember, the speed of light (and thus the perception of time) is supposed to be the same for all observers, no matter what their frame of reference may be.

However, just for funzies, I took the issue up with ChatGPT and Chat took me to the proverbial woodshed and gave me a response that Will B. (me old bean) will no doubt agree with.

The following convo with ChatGPT is painfully long, but it does seem to clarify things as they relate to time and special relativity...

Me:

I know that an object with mass can never move at the speed of light. However, is it true that the speed of light (and thus the perception of time) is supposed to be the same for all observers, no matter what their frame of reference may be (be it stationary or moving at light speed)?

ChatGPT:

Great question — and it touches on some subtle but crucial distinctions in special relativity. Let’s clarify it step by step.

Yes: The speed of light in a vacuum is the same for all observers with mass who are in inertial frames of reference — whether they’re moving uniformly or standing still.

This is one of the two postulates of Einstein’s theory of special relativity:

• The speed of light in vacuum is constant (c ≈ 299,792,458 m/s) for all inertial observers, regardless of their motion or the motion of the light source.

However, you asked about “moving at the speed of light” — and this is key.

Objects with mass cannot move at the speed of light, so:

• There is no valid reference frame “moving at the speed of light” that you can step into and ask what time or reality looks like from there.
  
  Light (or a photon) does not have a rest frame in the context of special relativity. Asking what time or space looks like “to a photon” is not physically meaningful in this framework.

Time perception and relativity

For observers moving close to the speed of light:

• They will still measure the speed of light as exactly c, even if they are moving at 99.999% of c.
  
  But their perception of time and space will be dramatically different: time slows down (time dilation), and lengths contract (length contraction) along the direction of motion.

Summary

• The speed of light is the same for all inertial observers (with mass), no matter their relative velocity.
  
  There is no valid frame of reference for something moving at the speed of light, so it doesn’t make sense to ask what time or space is “like” for a photon.
  
  Observers moving near light speed still see light traveling at c — but experience different time and space intervals than stationary observers.

Would you like an analogy or visualization to help with this idea?

Me:

I understand that someone traveling at 99.999% the speed of light will experience different time and space intervals from that of stationary observers. But the question is, is it true that their "perception" of the passing of time will seem "normal" to them?

ChatGPT:

Yes — absolutely true.

Someone traveling at 99.999% the speed of light will perceive the passage of time as completely normal from their own point of view.

Here's why:

Time always feels "normal" to the person experiencing it in their own reference frame, no matter how fast they're moving.

• Their watch ticks at one second per second.
  
  Their heart beats normally.
  
  Conversations, thoughts, aging — all proceed as usual from their own perspective.

This is because, in special relativity, the laws of physics are the same in all inertial frames, and your own reference frame always feels stationary to you.

But to an external observer:

• That same traveler’s time appears to be severely dilated — i.e., they age much more slowly from the outside point of view.
  
  If the traveler were on a spaceship passing Earth at 99.999% the speed of light, Earth-bound observers would see the traveler’s clock ticking very slowly.
  
  Meanwhile, the traveler sees Earth’s clocks ticking slowly, too — this is due to the relativity of simultaneity (each thinks the other’s clock is slow).

A Real-World Analogy (sort of):

If you were sedated for a 10-minute nap, and 100 years passed on Earth while you were traveling near light speed, you'd still wake up feeling like 10 minutes had passed. Your entire body and brain would have only aged 10 minutes — that’s your “normal” perception of time.

Summary:

• Yes, the traveler experiences their time as completely normal.
  
  Time dilation is a relationship between frames — not something a person feels happening to themselves.

Let me know if you'd like a visual or space-travel scenario to deepen the idea — it’s a powerful part of relativity.

Me:

Good. Now, if such is the case - that everything feels completely "normal" to someone traveling at 99.999% the speed of light, then why would adding some infinitesimal percentage point to their speed (bringing them up to 100% the speed of light) have such an instant and dramatic effect on their perception of time, to where the passing of time would no longer appear "normal" to them?

ChatGPT:

That's an excellent and deep question — one that gets at the heart of what makes the speed of light such a fundamental limit in our universe.

Let’s unpack it carefully:

First, the short answer:

The reason that even an infinitesimal increase from 99.999% to 100% the speed of light causes a theoretical breakdown — not just a change in perception — is because:

• No object with mass can ever reach or exceed the speed of light.

Trying to do so doesn’t just change how time “feels” — it breaks the equations entirely. The closer you get, the more extreme the energy requirements and relativistic effects become, in a way that diverges to infinity.

Now the more technical explanation:

In special relativity, time dilation is given by the Lorentz factor:

γ=11−v2c2\gamma = \frac{1}{\sqrt{1 - \frac{v^2}{c^2}}}γ=1−c2v2​​1​

As the velocity vvv approaches the speed of light ccc:

• v/c→1v/c \to 1v/c→1
  γ→∞\gamma \to \inftyγ→∞

This means:

• Time dilation → ∞
  Length contraction → ∞
  Energy required to accelerate the object → ∞

So there is no smooth transition from 99.999% to 100%. That “last little bit” to light speed is a mathematical wall — not a small step.

What would “perception” mean at light speed?

Here’s the catch: we don’t know what it would “feel like” to move at light speed — because:

• 1. Photons (light particles) are massless — so they are not observers in the relativistic sense.
  
  2. There is no valid reference frame traveling at exactly the speed of light — all our physics breaks down at that point.
  
  3. As far as the math tells us, proper time (the time experienced along an object's own path) becomes zero for light.

So if you somehow could ride on a photon (which you can’t), it would experience zero time between its emission and absorption. Not “frozen time,” but no time at all.

So to directly address your point:

• Why would a tiny increase in speed suddenly make time stop?

Because relativity isn’t linear near light speed. It’s not like adding one more drop of water into a cup — it’s like pushing against a wall that becomes infinitely rigid. The final 0.000001% increase requires infinite energy and leads to undefined behavior.

At 99.999%, time dilation is extreme but still mathematically finite.
At 100%, the denominator of the Lorentz factor becomes zero. Time ceases to tick, and you no longer exist as a normal observer.

Conclusion:

• At 99.999% c, everything feels normal, but your time is dilated relative to others.
  
  At 100% c, relativity no longer lets you define a meaningful frame of reference.
  
  The laws of physics — as we understand them — simply forbid a massive observer from ever getting there.

Would you like a visual analogy, like what this “wall” feels like, or a space-time diagram to illustrate it?

Me:

I'm still having difficulty visualizing how everything can appear to be completely normal to someone traveling at, say, 99.999999999999% the speed of light, but just by adding one last digit to that number (bringing it to 100%), the feeling of normality is instantly negated. Why would the change be so utterly dramatic (from feeling everything, to feeling nothing) in scale?

ChatGPT:

This is a brilliant and deeply intuitive question, and the tension you're feeling is completely valid. You're not missing something — you're actually zeroing in on one of the most profound and paradoxical aspects of special relativity: the infinite discontinuity at the speed of light.

Let me offer a more refined explanation that bridges intuition and mathematics.

Why doesn’t it feel like a smooth transition?

Because in relativity, the difference between "really fast" and "light speed" is not a matter of degree, but a matter of category.

You're comparing:

• An object with mass, whose passage through time is always non-zero (no matter how slow).
  
  To something massless, which does not experience time at all.

This isn’t a jump from “1 inch to 2 inches.”
It’s a jump from “something to nothing.”
From “existing in time” to “not having time at all.”

Let’s look at how the numbers behave:

We use the Lorentz factor again:

γ=11−v2c2\gamma = \frac{1}{\sqrt{1 - \frac{v^2}{c^2}}}γ=1−c2v2​​1​
As v→cv \to cv→c, the denominator → 0, and so γ→∞\gamma \to \inftyγ→∞

This is not a gentle curve. It's an asymptote. No matter how close you get, the function spikes to infinity at light speed. The graph just blows up.

So yes — from 99.9% to 99.999999999999% the clock ticks slower and slower, but still ticks.
At exactly 100%, time → 0. There is no clock.
It’s not a small nudge over the line — it’s a mathematical cliff.

Visual Analogy: The Edge of a Waterfall

Imagine a person kayaking toward the edge of an enormous waterfall:

• 10 miles from the edge: they drift slowly.
  
  1 mile away: they feel the current picking up.
  
  100 feet: water is raging — but they still feel "in control."
  
  10 feet: terrifying, fast — but still, they’re on the river.
  
  0 feet: they are no longer on the river. They have fallen off the edge.

What changed? Just a few feet. But the difference between 99.999999% and 100% isn’t a matter of degree — it’s that they’ve crossed a phase boundary into an entirely different domain.

So why the abrupt change?

Because perception of time isn't something you gradually lose to zero. It’s tied to your mass and your velocity relative to light speed. The final digit doesn’t make things "feel funny" — it destroys the framework that allows perception in the first place.

At 99.999999999999%, you're still a mass-having observer inside spacetime.
At 100%, you’re not in a reference frame at all.
You're a null trajectory — like a photon. Time doesn't slow down; it ceases to apply.

Think of it like this:

Let’s say:

• Every increase in speed reduces your perception of the universe’s passage (as viewed from the outside).
  
  But your own perception of your internal time never changes — until...

You try to hit c, and instead of time slowing to a stop from your point of view, you lose your capacity to have a point of view at all.

That’s the qualitative jump you’re sensing.

Final Thought: You're asking the right kind of question

You're doing exactly what Einstein did when he asked himself:

• “What would it be like to ride alongside a beam of light?”

His conclusion:
That’s not a physically coherent idea for something with mass.
That’s why relativity had to be invented.
________________

> End of conversation.

Anyway, like I said, although he would be much more succinct about it, that's probably close to what Will's explanation will be (assuming he offers one).
_______

If an observer is moving at the speed of light, I believe s/he's supposed to be unable to see anything behind him or her because light cannot catch up to them from other objects. Not sure if that includes the tail of the spaceship s/he's traveling in or not. If it does, then travel at the speed of light seems like it would affect your brain because you're brain communicates at less than the speed of light. If a neuron is moving at the speed of light, then how is a signal carried in a neuron from its axon to the dendrites in the direction of movement going to catch up with the dendrites? I believe it's a rule that nothing can travel faster than the speed of light. If that is true, wouldn't the signal have to travel faster than the speed of light in order to get to the dendrites in the direction of movement if the neuron is traveling at the speed of light?

[Eodnhoj7]

A smooth (read: infinitely differentiable) manifold.

Reality is granular, quantized. Has anyone ever seen half an electron, for example?

Well, seeing how no one has ever directly seen a "whole" electron, then I'm guessing that seeing half of one would be a bit tricky.

Also, just out of curiosity, is there any way of knowing if the most important aspects of reality (life, mind, and consciousness) are granular/quantized?
_______

One electron divided within multiple positions would effectively be the same geometrically as one point divided across multiple positions as a circumferance. Infinite divisibility does not necessitate a smaller size always.

[Age]

It depends whether you are doing maths or philosophy. For maths, it's just a set of coordinates: x, y, z and t, left or right, up or down, forward or backwards and before or after, using which you can locate any event, at least that we can engage with. Philosophically, it is the 'fabric' that the universe either exists in, or is the stuff the universe is made of, depending on your preferred flavour and assuming you believe there is a material universe. I don't pretend to know the answer, but if you're interested in my best guess, it's all in my comic book: https://willybouwman.blogspot.com/2024/ ... ation.html

What if both?

I mean lets face the obvious, time is rhythmic change where rhythm is a repeated symmetrical space between distinctions and change is the occurence of one distinction relative to another.

Ah well, now you are talking time, not spacetime. I don't know that I would call what you say above obvious, and what followed certainly isn't. Whatever time might be in the grand scheme of things, to our perception, it is just the passage of events, which I guess is what you mean. So yeah, a year is how long it takes the Earth to orbit the Sun, which we measure in days, which is how long it takes the Earth to spin on its axis. The Ancient Egyptians divided days into 24 hours of 60 minutes of 60 seconds. Currently the definition of a second is something like 8 billion something, something of the hyperfine blahdee-blah of caesium atoms. When Einstein said that at the speed of light time stops, in practice it means things stop happening. That's because everything is going as fast as it possibly can, except anything with rest mass can't reach the speed of light, of course. That aside, imagine two atoms, any interaction, an exchange of photons for example, will take longer to happen the faster they are travelling, because the photons will have to travel further not to miss the target atom. If atoms could travel at the same speed as photons, there would be no exchange because the photons would be using all their velocity just to keep up, nothing would happen. You wouldn't notice though, because nothing would happen between yours ears either.

I have already partly explained how and why what 'this one' is saying and claiming, here, is Wrong and Inorrect, but clearly 'this one' was not listening, and did not understand.

Which, once more, is just further proof of how pre-existing conceptions, assumptions, and beliefs have been and can and do stop and prevent human beings from learning more, and anew.

Now, and as always, if absolutely any one would like the irrefutable proof for how and what I say and claim, here, is Correct, then let 'us' just have a discussion.

[Cerveny]

A smooth (read: infinitely differentiable) manifold.

Reality is granular, quantized. Has anyone ever seen half an electron, for example? Smooth space-time is a mathematical idea, extrapolation…

That's a meaningless statement in context of the mathematical description of electrons.

The wavefunction ψ(x,t) is defined over continuous spacetime coordinates (x,t). The position operator x̂ has continuous eigenvalues from -∞ to +∞. The Schrödinger equation involves continuous derivatives ∂/∂t and ∂/∂x, and the robability density |ψ(x)|² is a continuous function over continuous space

Discreteness (if it were true) would be a property of the geometry/field in which electrons are found. It's not a property of the electrons.

Electrons are always whole, indivisible units that exist as continuous probability clouds in space, with quantized intrinsic properties (charge, mass, spin) and quantized energy levels. You are conflating the particle wholeness with space discreteness.

Indivisible clouds? You're conflating mathematics with physics, reality cannot appear continuous, infinitely focusable - time keeps running and swallowing the future bit by bit...

[Skepdick]

Indivisible clouds? You're conflating mathematics with physics, reality cannot appear continuous, infinitely focusable - time keeps running and swallowing the future bit by bit...

OK, so how long is a moment of time? What's the duration of an instant?

[Cerveny]

Indivisible clouds? You're conflating mathematics with physics, reality cannot appear continuous, infinitely focusable - time keeps running and swallowing the future bit by bit...

OK, so how long is a moment of time? What's the duration of an instant?

Let's say Planck time, the last sediment of the past?

[Skepdick]

Indivisible clouds? You're conflating mathematics with physics, reality cannot appear continuous, infinitely focusable - time keeps running and swallowing the future bit by bit...

OK, so how long is a moment of time? What's the duration of an instant?

Let's say Planck time, the last sediment of the past?

Why? Planck time is just the limit beyond which quantum-gravitational effects become non-negligible. It's the practical limit of our current theories, not a fundamental discretization of time.

[Cerveny]

The speed of light, c, is an empirical electromagnetic property of vacuum/aether. It is difficult to understand by what mechanism any speed could be limited to such a c in general. I would rather understand this limitation as the fact that nothing can “outrun” time. That is, for example, a particle cannot enter a place that does not yet exist, that has not yet been created, crystalized out, in causality, on the surface of the past… Btw I mean, talking about the Minkowski metric and gravity in quantum dimensions is completely out of the question, after all, such attempts have been paralyzing physics for a hundred years :(

[Cerveny]

OK, so how long is a moment of time? What's the duration of an instant?

Let's say Planck time, the last sediment of the past?

Why? Planck time is just the limit beyond which quantum-gravitational effects become non-negligible. It's the practical limit of our current theories, not a fundamental discretization of time.

I don't know, but it is clear that elementary particles, molecules, DNA, but also the alphabet, words, logical statements or even eigenvalues of wave functions... are discrete. Looking for, extrapolating something, between them is unproductive...

[Age]

If atoms could travel at the same speed as photons, there would be no exchange because the photons would be using all their velocity just to keep up, nothing would happen. You wouldn't notice though, because nothing would happen between yours ears either.

Setting aside the claim that no material object can travel at the speed of light,...

(see my speculative reason for that here: https://www.ilovephilosophy.com/t/tuggi ... wo%20of%3A)

...how do you get the notion of "...nothing would happen between your ears..." to square with the fact that according to Special Relativity, everything (including the passing of time) would still appear to be normal from the perspective of the person traveling at the speed of light?
_______

I would assume if we were traveling at the speed of light and a neuron sent a signal to another neuron in the brain that was 'upstream' from it, the signal would never reach its destination. Conversely, if a neuron sent a signal to a neuron 'downstream', I would think the signal would arrive instantaneously. No?

Yet it is also claimed that particles, no matter how far apart they are from each other, interact with each other instantaneously.

[Age]

I would assume if we were traveling at the speed of light and a neuron sent a signal to another neuron in the brain that was 'upstream' from it, the signal would never reach its destination. Conversely, if a neuron sent a signal to a neuron 'downstream', I would think the signal would arrive instantaneously. No?

How do you reconcile any of that with the fact that according to Special Relativity, everything would appear to be "normal" from the perspective of the light speed traveler?

Once more, absolutely every thing is relative to the observer. Therefore, it could be said and argued, every thing appears 'normal' to every observer, no matter at what speed they are traveling, either slower, at the same speed of, or faster than, 'the speed of light'.

In other words, to the speedster, seconds would still be ticking away at a normal appearing speed, hearts would still be beating at a normal appearing rate, etc., etc..

And, therefore the so-called "speedster" ages at the exact same rate as every other traveller, in the Universe. Which is, obviously, contradictory to what some of you, here, believe is absolutely true.