do radio waves propagate the same, and would our radio equipment work

yes. the speed of light is the same in all frames of reference. just the frequency would shift. towards blue i would think, seeing how the reverse is true in this expanding universe.

transition said:

do radio waves propagate the same, and would our radio equipment work

Can’t see why not.

I wanna know for sure.

transition said:

I wanna know for sure.

Why?

Stephen Hawking used to think time would go backwards in a contracting universe, but changed his mind.

Bubblecar said:

transition said:

I wanna know for sure.

Why?

preparedness, wanna upgrade me alfoil hat

Bubblecar said:

Stephen Hawking used to think time would go backwards in a contracting universe, but changed his mind.

I could never understand that view.

ChrispenEvan said:

Bubblecar said:

Stephen Hawking used to think time would go backwards in a contracting universe, but changed his mind.

I could never understand that view.

It did seem a rather basic mistake to ignore thermodynamics.

Yes, the arrow of time and all that.

How long would the universe take to shrink to an incoherent mess of energy if it shrunk at the same rate it is now expanding after the BB?

transition said:

I wanna know for sure.

For sure. The universe would have to be contracting for a very long time before Olbers Paradox kicked in and fried everyone, and even then radio would continue to work until the radio set melted.

Postpocelipse said:

How long would the universe take to shrink to an incoherent mess of energy if it shrunk at the same rate it is now expanding after the BB?

I might be able to answer that. I’ll think about it.

there’d be a lot more EMR noise

i’m not sure radio would work in a contracting universe, or in some contracting area of space.

I’d expect the sorta impedance of space’d be different too, so all those antennas, whatever’t is they couple into (the aether), it’d be different.

transition said:

there’d be a lot more EMR noise

i’m not sure radio would work in a contracting universe, or in some contracting area of space.

I’d expect the sorta impedance of space’d be different too, so all those antennas, whatever’t is they couple into (the aether), it’d be different.

We’ll need the detailed model before passing judgment, and you’ll have to show your working.

there’d be a lot more EMR noise

i’m not sure radio would work in a contracting universe, or in some contracting area of space.

I’d expect the sorta impedance of space’d be different too, so all those antennas, whatever’t is they couple into (the aether), it’d be different.

a) why?

b) Why?

c) Why? Radio works fine in an expanding universe. there is no “ether”. antennas are “coupled” to the emr field. Space would just be getting smaller so wavelength will get shifted to the blue.

a) why?

because the noise floor somewhere between >100-400meg? (depending what you’re doing) stops being local noise, or isn’t mostly local noise?

b) Why?

c) Why? Radio works fine in an expanding universe. there is no “ether”. antennas are “coupled” to the emr field. Space would just be getting smaller so wavelength will get shifted to the blue.

space has an characteristic impedance, or equivalant impedance?

because the noise floor somewhere between >100-400meg?

how would a contracting universe affect this?

space has an characteristic impedance, or equivalant impedance?

space has vacuum permeability or magnetic constant and the vacuum permittivity or electric constant, this gives us the speed of light in a vacuum. so if these don’t change, and we have no reason to believe so as the SoL hasn’t changed from the BB. as far as we know.

https://en.wikipedia.org/wiki/Impedance_of_free_space

so would dipoles and end-fed antennas be optimized the same legth in a contracting universe, and would transmission lines be optimally 50 ohm, 300 etc.

a contracting universe wouldn’t affect our radio transmission for the same reasons the expanding ones don’t, the expansion is only evident on large scales, megaparsecs, and non-gravitationally bound objects within the universe.

ChrispenEvan said:

a contracting universe wouldn’t affect our radio transmission for the same reasons the expanding ones don’t, the expansion is only evident on large scales, megaparsecs, and non-gravitationally bound objects within the universe.

dunno, but do reckon there’d be a lot more radio noise, the sky’d be lit up at night, so there’d be more EMR noise.

In a contracting universe, radio waves work the same, locally, but the incoming flux of radio waves from elsewhere would be higher.

dv said:

In a contracting universe, radio waves work the same, locally, but the incoming flux of radio waves from elsewhere would be higher.

i’m still not sure of the former.

oh well. unless you have some reasoning behind it it don’t count for much.

ChrispenEvan said:

oh well. unless you have some reasoning behind it it don’t count for much.

Doesn’t count for much any way, mate. Good isn’t‘t.