speed of light?

[deckster]

eharding said:

Both measures are simply a reflection of how vanishingly brief the human lifespan is in the scheme of things.

A species with an individual lifespan of tens or hundreds of millennia probably wouldn't be so grumpy and bent out of shape about how unfair the scale and fundamental speed limit of the universe are.

To an extent, but there is a more fundamental disconnect here in that there it is simply impossible at a very basic level for us to know what is happening at Alpha Centauri right now, or affect it in any way. The fact that, no matter how long your lifespan, you are effectively cut off from any kind of real-time interactions with anything that isn't in your absolute immediate vicinity is surely uncomfortable for any sentient intelligence.

[Upinflames]

So is it a coincidence that the great pyramid at Giza lies on 29.9792458°N.?

[deckster]

Upinflames said:

So is it a coincidence that the great pyramid at Giza lies on 29.9792458°N.?

Of course it is. Unless you accept that not only did the Egyptians know the speed of light to a high degree of specificity, they also knew how we were going to measure the location of places on the globe plus also the SI units that we were going to adopt 6,000 years down the line.

[ATG]

67Dino said:

Krikkit said:

skeeterm5 said:

67Dino said:

Personally, I find the concept of time the most fascinating and slippery of all ideas in Physics. By which I mean, I haven’t a clue really.

I agree with you on that point, the more you think about it the more complicated it seems to be and the more the explanations seems to have to become more complex to explain things.

There's nothing particularly "slippery" about time in this context, it's just that the translation into the real world from the maths that actually expresses it isn't up to the job.

I’m not sure I agree. I’ve a degree in Physics and know that lots of concepts are hard to grasp due to the maths being different to the familiar world we inhabit. Time has this plus it is also still debated if it is even is a real thing at all. Quantum mechanics doesn’t even care which way it flows which raises some real questions at its existence. That seems pretty slippery to me…

Agreed.

A lot of people are prepared to wet the bed about free will. "I experience it therefore it must be real." I personally think that is daft, but I do have similar nagging concerns about Physic's description of time versus our experience of it.

[ATG]

deckster said:

eharding said:

Both measures are simply a reflection of how vanishingly brief the human lifespan is in the scheme of things.

A species with an individual lifespan of tens or hundreds of millennia probably wouldn't be so grumpy and bent out of shape about how unfair the scale and fundamental speed limit of the universe are.

To an extent, but there is a more fundamental disconnect here in that there it is simply impossible at a very basic level for us to know what is happening at Alpha Centauri right now, or affect it in any way. The fact that, no matter how long your lifespan, you are effectively cut off from any kind of real-time interactions with anything that isn't in your absolute immediate vicinity is surely uncomfortable for any sentient intelligence.

Is it bks. I crave a bit of peace and quiet. If I could transport my study outside the light cone of all my colleagues, I would bloody rejoice.

[annodomini2]

NMNeil said:

One thing being overlooked is just how incredibly slow the speed of light actually is.
I'm open to correction but the closest solar system to ours is Alpha Centauri. If you could travel at 10 times the speed of light it will still take you about 3 months to get there even ignoring acceleration to that speed and deceleration at the end.
Grab a beer and a comfy chair to get a better idea.
https://www.youtube.com/watch?v=1AAU_btBN7s

At 10x the speed of light you would arrive 100's of yrs in the past

At 90% the speed of light, roughly 6yrs will have passed on Earth, but the journey would be about 2 weeks for the passengers.

[Fusion777]

annodomini2 said:

At 10x the speed of light you would arrive 100's of yrs in the past

At 90% the speed of light, roughly 6yrs will have passed on Earth, but the journey would be about 2 weeks for the passengers.

What’s the calculation for the first bit based on? Relativistic effects aren’t strong enough at 90% of c to give that much difference in time. You’ve got to be going much faster.

[Ash_]

Fusion777 said:

annodomini2 said:

At 10x the speed of light you would arrive 100's of yrs in the past

At 90% the speed of light, roughly 6yrs will have passed on Earth, but the journey would be about 2 weeks for the passengers.

What’s the calculation for the first bit based on? Relativistic effects aren’t strong enough at 90% of c to give that much difference in time. You’ve got to be going much faster.

Yep, for my microscopic brain the first bit doesn't compute. The 2nd does due to relativity (I think).

The first bit if you travelled to Alpha Centauri at 10x c, the journey would take about 5 months (Earth time I guess, for the crew significantly less?). So you'd still arrive 5 months of Alpha Centauri time after you left, though as we're seeing it as it was 4.3 years ago, you'd actually be able to witness it going back in time (if you could observe it as you travelled)? I don't understand or know why (or indeed how) you'd arrive "100's of years in the past".

The speed of light, our limited understanding of it, it's limit etc, etc, really does fk up everything doesn't it?

[Fusion777]

You have to be *really* shifting to see very significant relativistic effects:



http://hyperphysics.phy-astr.gsu.edu/hbase/Relativ...

This link shows the formulae involved. At 0.9c, time dilation is about a factor of 2.3x. Significant, but nothing like the example quoted earlier.

[NMNeil]

eharding said:

A species with an individual lifespan of tens or hundreds of millennia probably wouldn't be so grumpy and bent out of shape about how unfair the scale and fundamental speed limit of the universe are.

Edited by eharding on Sunday 24th July 23:47

Many PH members are renowned for being grumpy about speed limits, so you may be onto something

[dukeboy749r]

I had to Google the pyramid reference. Sadly, however, I got this.

It will always be close, but no cigar…

https://fullfact.org/online/great-pyramid-speed-of...

[Halmyre]

deckster said:

Upinflames said:

So is it a coincidence that the great pyramid at Giza lies on 29.9792458°N.?

Of course it is. Unless you accept that not only did the Egyptians know the speed of light to a high degree of specificity, they also knew how we were going to measure the location of places on the globe plus also the SI units that we were going to adopt 6,000 years down the line.

It's an Easter Egg planted by the programmers who created the virtual world we all live in. Mock ye not, apparently the speed of light is an indication we live in a simulation:

https://www.scientificamerican.com/article/confirm...

[67Dino]

Halmyre said:

deckster said:

Upinflames said:

So is it a coincidence that the great pyramid at Giza lies on 29.9792458°N.?

Of course it is. Unless you accept that not only did the Egyptians know the speed of light to a high degree of specificity, they also knew how we were going to measure the location of places on the globe plus also the SI units that we were going to adopt 6,000 years down the line.

It's an Easter Egg planted by the programmers who created the virtual world we all live in. Mock ye not, apparently the speed of light is an indication we live in a simulation:

https://www.scientificamerican.com/article/confirm...

That’s properly mind blowing, thanks. Hope whatever is controlling me in the simulation enjoyed that too…

[Fusion777]

Must admit I’d not heard of the pyramid coincidence before this thread. Normally these sorts of coincidences are a bit naff, but I thought that one was pretty cool.

[Ayahuasca]

NMNeil said:

One thing being overlooked is just how incredibly slow the speed of light actually is.
I'm open to correction but the closest solar system to ours is Alpha Centauri. If you could travel at 10 times the speed of light it will still take you about 3 months to get there even ignoring acceleration to that speed and deceleration at the end.
Grab a beer and a comfy chair to get a better idea.
https://www.youtube.com/watch?v=1AAU_btBN7s

Hold on, if you left the sun riding on a photon and looked back, like in the video, how would the sun reduce in size as it got further away? You would just see the light that travelled with you, so you wouldn’t see light that left the sun later, so how would you see it getting smaller ?

(Small brain, easily confused..)