How does Wireless work so well?
How does Wireless work so well?
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Discussion

wanty1974

Original Poster:

3,704 posts

278 months

Friday 10th June 2005
quotequote all
Call me an old chav and all that, but here I sit, 10 metres from my wireless ADSL point, receiving all of TwinCam's opinions about general UK politics and I wonder how on earth such data can be transfered over the air so quickly.

Any people who can explain this wonderment to me?

rebelstar

1,146 posts

274 months

Saturday 11th June 2005
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Alert Einstein said:
"You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat."

malman

2,258 posts

289 months

Saturday 11th June 2005
quotequote all
you're an old chav!

The simple answer is you don't really want to know as this would cause your brain to fillup and have to dump a chunk of longterm memory. If I explained it all, you would probably forget your 10th birthday party or some other vital past events

If you really want to twist your melon think about this.

You are in Australia and pickup your mobile phone and tap in a number and press the call button 20 seconds later you are talking to your friend in the UK - WOW!

Vipers

33,506 posts

258 months

Saturday 11th June 2005
quotequote all
Radio signals travel at the same speed as light which is roughly 186,000 miles PER SECOND,

Ever tried putting Radio 2 on you Sky box, and the radio at the same time, there is a slight delay in the reception, coz the signal is travelling up to the satelite, and back to your aerial, which adds a few milisends to the time.

Another interesting one about sound speed, a person in Australia will hear big ben dong on his radio before a person standing on the pavement below it, this is due to the vast difference in the speed of a radio wave, and the speed of sound. Urts the brain dont it.

mindgam3

740 posts

266 months

Saturday 11th June 2005
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Vipers said:

Another interesting one about sound speed, a person in Australia will hear big ben dong on his radio before a person standing on the pavement below it, this is due to the vast difference in the speed of a radio wave, and the speed of sound. Urts the brain dont it.


That's assuming the time it takes for the sound to travel to the microphone which is recording big ben, the time it takes for the radio sound to travel to the Aussies ear and the processing time at either end is less than the time it takes for the sound to travel down to the guy on the pavement

-DeaDLocK-

3,368 posts

281 months

Saturday 11th June 2005
quotequote all
wanty1974 said:
Call me an old chav and all that, but here I sit, 10 metres from my wireless ADSL point, receiving all of TwinCam's opinions about general UK politics and I wonder how on earth such data can be transfered over the air so quickly.

Any people who can explain this wonderment to me?
Don't even think about consumer wireless devices when it comes to computing - we're barely scratching the surface. It's all radio waves, and it's the same thing that transmits mobile phone signals, terrestial TV, walkie talkie broadcasts etc.

If you think wireless data transmission is cool, wait till wireless *electricity* becomes common place. It's already been done...

_dan_

2,392 posts

309 months

Sunday 12th June 2005
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It's all down to the high frequencies WiFi uses (2.4Ghz and 5Ghz), which is up in the microwave region.

Basically, the higher the frequency, the more data you can pack into it. Along the same principle as FM radio (88 to 108 Mhz) being good quality stereo radio and short wave (about 500Khz to 1500kHz) being crap quality!!

Basic explaination here

More in-depth here

>> Edited by _dan_ on Sunday 12th June 00:43

Mr E

23,075 posts

289 months

Sunday 12th June 2005
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-DeaDLocK- said:

If you think wireless data transmission is cool, wait till wireless *electricity* becomes common place. It's already been done...


Eh?

rebelstar

1,146 posts

274 months

Sunday 12th June 2005
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I think he's talking about electrical induction. That's how RFID tags work, and now some wireless mice and phone chargers. It's very low power and short distance - don't expect your washing machine to be wirelessly powered anytime soon.

>> Edited by rebelstar on Sunday 12th June 10:18

ATG

23,801 posts

302 months

Sunday 12th June 2005
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Tesla experimented with "wireless" power distribution in houses. He used enormously powerful electromagnetic fields ... I'll see if I can find any pictures ...

Well, hree's a link to some text in which he describes his global power transmission scheme http://mysite.verizon.net/vzeoyr81/magtrans.html

>> Edited by ATG on Sunday 12th June 10:42

chrisjl

787 posts

312 months

Sunday 12th June 2005
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ATG said:
Tesla experimented with "wireless" power distribution in houses. He used enormously powerful electromagnetic fields ... I'll see if I can find any pictures ...

Wouldn't that make your fillings hum and your cutlery stick to the walls?

ATG

23,801 posts

302 months

Sunday 12th June 2005
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chrisjl said:

ATG said:
Tesla experimented with "wireless" power distribution in houses. He used enormously powerful electromagnetic fields ... I'll see if I can find any pictures ...


Wouldn't that make your fillings hum and your cutlery stick to the walls?


Quite possibly. Think along the lines of living inside a microwave oven.

malman

2,258 posts

289 months

Sunday 12th June 2005
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ATG said:

chrisjl said:


ATG said:
Tesla experimented with "wireless" power distribution in houses. He used enormously powerful electromagnetic fields ... I'll see if I can find any pictures ...



Wouldn't that make your fillings hum and your cutlery stick to the walls?



Quite possibly. Think along the lines of dying inside a microwave oven.


Vipers

33,506 posts

258 months

Sunday 12th June 2005
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mindgam3 said:

Vipers said:

Another interesting one about sound speed, a person in Australia will hear big ben dong on his radio before a person standing on the pavement below it, this is due to the vast difference in the speed of a radio wave, and the speed of sound. Urts the brain dont it.



That's assuming the time it takes for the sound to travel to the microphone which is recording big ben, the time it takes for the radio sound to travel to the Aussies ear and the processing time at either end is less than the time it takes for the sound to travel down to the guy on the pavement
As far as I know, the microphone is in the bell tower itself, so thats why the guy in oz hears it first,

Mr E

23,075 posts

289 months

Sunday 12th June 2005
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rebelstar said:
I think he's talking about electrical induction. That's how RFID tags work, and now some wireless mice and phone chargers. It's very low power and short distance - don't expect your washing machine to be wirelessly powered anytime soon.


Ah, yes, quite cool but hardly new.....

And you're never going to power anything big with it....

bluebell

11 posts

256 months

Monday 13th June 2005
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do radio waves stretch as they approach the speed of light

TeamD

5,060 posts

262 months

Tuesday 14th June 2005
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bluebell said:
do radio waves stretch as they approach the speed of light


Relative to what?

rebelstar

1,146 posts

274 months

Tuesday 14th June 2005
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Since radio waves and visible light both form part of the electromagnetic spectrum, they surely move at the speed of, uh, light.

However, I still don't understand why radio waves go through walls, but light doesn't... although the current arrangement suits me fine.

-DeaDLocK-

3,368 posts

281 months

Wednesday 15th June 2005
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rebelstar said:
However, I still don't understand why radio waves go through walls, but light doesn't...
Light waves go straight, radio waves bounce.

I think.