I was travelling on a plane (so I’m presuming 600 mph?) and, of course, Bluetooth earphones worked fine with my tablet. Though I guess we were in a vacuum.
If you were outside the plane travelling at that speed, would the earphones still be able to connect to the tablet?
Does relative speed affect the connection, or is the only important factor the distance between the two devices?
In addition, how far would it work in space? 😆
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Bluetooth uses radio waves which travel at the speed of light, so a plane is absolutely nothing compared to that. Basically the same as standing still
And you aren’t in a vacuum because in a vacuum you can’t breath
Planes are not in vaccuums. They are under pressure. If the inside of a plane was a vaccuum there would be no air, you would suffocate.
Both your earphones and your tablet are travelling at 600mph. So when the signal leaves one device, it is travelling 600mph faster than it normally would. Which overall has no effect, because the device receiving it is also travelling 600mph faster.
If you flew your tablet at 600mph past your earphone on the ground, they would receive some connection based on the range of bluetooth, so probably about 30ft-50ft? But it wouldn’t help much because the plane would be gone before you could do anything with that signal.
In general, radio waves aren’t affected by relative speed. Don’t forget, Earth is travelling through space at huge speeds, and radio still works.
In space, there is a vaccuum. No air, means nothing to ‘catch’ the radio waves as they travel, meaning they can go much much further. I don’t know what the theoretical range of bluetooth would be in space.
I’m confused how you thought you managed to stay alive in a vacuum.
I’m also confused what you’re actually asking, since Bluetooth only has a range of a few metres and connection takes a finite time, so you’d never notice if you could connect to a speaker you passed at 600 mph.
But assuming you had an ultra high power Bluetooth device that had a range of many miles, then realistically no it wouldn’t matter if you were moving relative to the thing you wanted to connect to. Light is really really really fast, fast enough to go round the earth 7 times in one second. A plane is essentially stationary as far as light / radio waves / etc are concerned. It makes no difference if there is air or the vacuum of space separating the devices, radio waves happily travel across both. If you had an ultra high power Bluetooth thing, and a magical spacecraft that could travel at half the speed of light or something and gunned it towards your speaker, then Bluetooth wouldn’t work as the signal would be Doppler shifted to a frequency range where the equipment doesn’t work any more. (Like how an ambulance siren or train changes pitch as it goes past, a similar thing happens to light when you get to speeds close to light speed)
The only things that matter are distance between devices, their speed relative to each other, and if there any obstacles between them.
Signal strength reduces with square of the distance, so if the distance gets 2x larger, the signal goes 1/4th weaker. Technically, the signal never really dies out: no matter how far away, it’s still there. But it becomes harder and harder to detect that weak signal.
Walls reduce passing signal, depending on material. Metals reduce most signals by a lot, so the plane’s hull (made from aluminum) should be almost impenetrable. But signal can still pass through windows, so I think your earphones would still connect even outside the plane (but you may loose reception if you hide between windows).
The relative speed changes “color” of the signal. If the receiver moves towards the source, it sees it more “blue”, if it moves away – more “red”. The effect is quite small and Bluetooth auto-corrects for color slightly. However, if the relative speed is very big, the signal can go out of “Bluetooth color range” and become invisible for the device.
No, there is no speed limit. Bluetooth works over radiowaves, which is light and the speed of light is the same for all observers because light doesn’t need a medium.
However, if you were traveling at a significant fraction of the speed of light and the phone wasn’t, ignoring distances, they wouldn’t be able to communicate properly because they would be experiencing a different passage of time.
I’m not sure how Bluetooth handles its connection exactly, so let’s use a radio as an example. If you are traveling very fast, and I am standing still broadcasting a radio signal to you, for you to pick it up, your radio would have to be set to a different frequency than I am broadcasting at. Higher if you’re moving towards me, lower if you’re moving away from me, and if you’re moving in a circle around me, higher. See special relativity (general relativity for the case of the circle)
Physics works the same no matter what you set as your frame of reference, as long as two things aren’t moving relative to each other, they behave as if they are at rest.
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