Ask any question you want about Physics

originally posted by: Bedlam

originally posted by: dragonridr

originally posted by: BASSPLYR
Could my modem sitting abut to my bass speaker cabinet reduce my WiFi?

I've noticed that since I moved my WiFi router next to my speakers I get half the range for the signal than before the move.

Not even sure radio waves would be effected by speaker magnets but anybody wanna take vs stab at the physics behind my reduced range on my wifi? Would a microwave oven also serve to interfere with wifi?

Yes you get what's called radio interference.

From a microwave, maybe - they're in the same frequency range as the wi-fi. Unless it's 5GHz.

From speakers, no. Speakers do not emit RF.

Ever taken a call in your car and hear a weird buzzing over yoir speakers?

You're hearing the transmission bursts from the phone being rectified by semi junctions in the amplifier.

These waves are all happening in one room radio frequencies cell phones speakers wifi, microwaves even other electronics like tvs will put off em radiation.

Speakers are totally passive.

What any electronics emits em radiation. But speakers are actually quite high since there job is to pick up frequencies. In fact speakers don't have to be on to emit em radiation.

originally posted by: dragonridr
In fact speakers don't have to be on to emit em radiation.

Please elaborate.

originally posted by: BASSPLYR
Not even sure radio waves would be effected by speaker magnets but anybody wanna take vs stab at the physics behind my reduced range on my wifi? Would a microwave oven also serve to interfere with wifi?

Ever hear of a "Faraday cage"?

It's a metal enclosure that blocks electromagnetic frequencies. It can have holes in it and still work depending on what frequency range you're trying to block.

Depending on the speaker, the magnet us usually encased in metal and in most of my speakers there's even more metal connecting the metal enclosing the magnet to the metal supporting the speaker cone. Then there's the cabinet itself.

Wifi Killers

The positioning of your router can also have a tremendous impact on performance. “Problems start to occur when you get the router in the wrong position, such as on the floor or behind a cabinet,” said D-Link’s Roger Tao. “People are hiding it because they don’t want to see it.”

I try to put mine on top of a bookshelf, to get the best range.

What can get in Wi-Fi's way?

The 10 home technologies, appliances and other objects that could block your Wi-Fi

originally posted by: dragonridr

What any electronics emits em radiation.

No, no it doesn't.

A nice class A amp with no input doesn't, for instance. You have to be handling a signal that is high enough frequency to radiate. For digital circuits, the FCC says anything with a clock less than 8kHz isn't worth registering.

But speakers are actually quite high since there job is to pick up frequencies. In fact speakers don't have to be on to emit em radiation.

Speakers are a coil of wire and a magnet. They're a big paperweight. They don't "pick up frequencies" either. And there isn't really an "on" or "off" for a coil of wire and a magnet.

a reply to: Arbitrageur

I'd say Kerbal Space, just for a laugh, but actually I have never heard it mentioned as a factor in calculating an asteroid's potential course change when coming close to a planet. Like apophis, for instance. The 'gravitational keyhole' was scrutinized very closely to see if it should be raised on the Torino scale. And several articles explaining how this was calculated and the trajectory was plotted never mentioned magnetic fields as being a factor in perturbing it's orbital path. Just gravity.

originally posted by: pfishy
Like apophis, for instance.

Apohhis isn't an iron asteroid, it's thought to be a type LL chondrite, so maybe 1% metallic iron. Iron meteorites might be over 90% iron, like the Willamette Meteorite.

However if you find an example of an iron meteorite that passed relatively close to Earth where we measured the trajectory change, please let me know.

Since you mentioned rocky Apophis, can I assume you know of no data to support this? "Seeing as how an iron meteorite may pass through our planetary magnetic field, and it is not even a discernable factor in any course alterations."

a reply to: Arbitrageur

Well, my mistake then. Stupid assumption about the make-up of Apophis on my part.
I don't actually know of any that have been measured. I was just stating that I have never heard of it being a factor in trajectory calculations. I am going to stick my face back into the internet and double check myself before I open my mouth about orbital dynamics again.
Thanks.

originally posted by: Bedlam

originally posted by: dragonridr

What any electronics emits em radiation.

No, no it doesn't.

A nice class A amp with no input doesn't, for instance. You have to be handling a signal that is high enough frequency to radiate. For digital circuits, the FCC says anything with a clock less than 8kHz isn't worth registering.

But speakers are actually quite high since there job is to pick up frequencies. In fact speakers don't have to be on to emit em radiation.

Speakers are a coil of wire and a magnet. They're a big paperweight. They don't "pick up frequencies" either. And there isn't really an "on" or "off" for a coil of wire and a magnet.

As far as speakers they do indeed emit em radiation unless you shield them. In fact that's why even doing things like opening a laptop and forgetting to put back a screw can lead to interference. Laptops rely on shielding to avoid interference. But I'm not going to keep this stupid argument going if you don't understand moving electrons creates Wm radiation I can't help you. But as far as the speakers here's someone that tested theirs.

originally posted by: dragonridr
But as far as the speakers here's someone that tested theirs.

At 1:40 he sets the meter right on top of a speaker cabinet and the meter doesn't seem to register any increase when he does that, so I think the video actually contradicts the claim that speakers emit EM radiation if they are off.

For the other speaker, he admits that one is on and connected to his amplifier, and yes it emits EM radiation when it's on.

originally posted by: Arbitrageur

originally posted by: dragonridr
But as far as the speakers here's someone that tested theirs.

At 1:40 he sets the meter right on top of a speaker cabinet and the meter doesn't seem to register any increase when he does that, so I think the video actually contradicts the claim that speakers emit EM radiation if they are off.

For the other speaker, he admits that one is on and connected to his amplifier, and yes it emits EM radiation when it's on.

Why WOULD THEY have EM Radiation off?? Now in standby that's diffrent which is the state most stereo systems set in. Again electricity has to be moving you know this.

My question is, what makes gravity, is it the mass of objects bending space or it the result of a force carrier like the graviton which we have not found yet?

Or is it some other mechanism.

originally posted by: dragonridr
Why WOULD THEY have EM Radiation off??

I asked you first, in reply to this statement of yours:

originally posted by: dragonridr
In fact speakers don't have to be on to emit em radiation.

I asked you to clarify that statement as I didn't know what you meant.

a reply to: bhaal
We don't know. The graviton my exist and it's just too hard to detect it, or the hypothesis of the graviton may be false. Quantum gravity is an active area of research and it's difficult to make general relativity compatible with quantum mechanics as most QM is involves renormalization and gravitation is non-renormalizable.

a reply to: Arbitrageur

OK I'll rephrase speakers don't have to be playing to emit em radiation depending on the set up of the sprakers. Speakers in modern electronics such as sound bars etc tend to stay powered on. Any em source can interfere with a frequency if it's close enough like putting a wifi router on a speaker.

a reply to: dragonridr
OK that makes a lot more sense, thanks for clarifying.

I was reading somewhere about how many power plants in the USA would need to be operating at full capacity just to power all the devices which are "turned off", and it was a surprising number a while back, (it's probably more now) but that included not only the "standby mode" the guy talked about in the video you posted, but also included the "bricks" or transformers that plug in the wall or the inline "bricks" in laptop power cords which consume electricity and convert it to heat even when the device they are supposed to power is completely off.

The Xbox and Playstation gaming consoles use about 13W in one of their "off" modes, Wii does that only for a short time after turning it off then drops to 0.3W, though I have to disagree with this author's claim that 0.3W is "truly off", which to me would be 0W, though 0.3W is a big improvement over 13W. I guess you either have to unplug devices or plug them into a power strip with a switch on it and use the switch to really turn them off:

arstechnica.com...

The Natural Resources Defense Council recently put out an alarming press release claiming the Xbox One is causing consumers to waste an aggregate of $250 million annually in energy costs. The culprit: the "instant on" mode that draws significant power 24 hours a day, even when the system is supposedly "off."

The NRDC put out the release in an effort to convince Microsoft to turn off this "instant on" setting by default, or to at least offer an option to turn it off on the system's initial setup (as it does in Europe).
...

OK, "turn off your consoles when you're not using them" is kind of an obvious tip. The tricky part is that all three major consoles have two levels of "off" these days; one that's truly off (drawing only about 0.3W to detect a power signal from a controller); and one that puts the system in a power-hogging "standby" mode (like the Xbox One's "instant on" mode).

So why does Europe get the option to not waste all that energy while the US is shafted with waste by Microshaft?

I'd rather game on a PC anyway, but that's just one device that wastes $250 million annually in energy costs, which is terrible. People say we are doomed to carbon-related climate change and there's not much we can do, well that's something Microsoft and Sony could do right there, stop wasting 13 Watts when the consoles are off.

originally posted by: bhaal
My question is, what makes gravity, is it the mass of objects bending space or it the result of a force carrier like the graviton which we have not found yet?

Or is it some other mechanism.

Ambient time and dark matter is responsible for gravity imo.

a reply to: dragonridr

That would be "accelerating electrons", a DC current emits no RF. It's a bit more complex IRL. What's the wavelength of 20kHz? And how does that match to the length of the speaker wire? Right. No radiation will occur. You'll get low level near field stuff but diddley for EM.

originally posted by: Nochzwei

originally posted by: bhaal
My question is, what makes gravity, is it the mass of objects bending space or it the result of a force carrier like the graviton which we have not found yet?

Or is it some other mechanism.

Ambient time and dark matter is responsible for gravity imo.

Well in special relativity gravity has sort of an explination, Einstein has something called space time a dimension of our universe just like any other spatial coordinates. Time and space are interconnected and cannot be separated. I know what does this have to do with gravity well its a property of space time. Let's see how to explain this when you move through space you are compelled to move through time but, when you move through time (which of course you are always doing) you do not have to move through space.So when we move through space ( to an outside observer) we also travel through time. When a mass is present in the above space-time it distorts it so that it remains true that travelling through space causes you to travel through time, travelling through time now causes you to move (accelerate) through space. In other words just by existing, you are compelled to move through space - this is gravity. What we don't understand is what is the mechanism that allows mass to drag is through time. But this also leads to a weird result if you could find a way to stop time gravity wouldn't exist. You become separate from the entire universe and become an outside observer.

originally posted by: [post=19495022]dragonridr But this also leads to a weird result if you could find a way to stop time gravity wouldn't exist. You become separate from the entire universe and become an outside observer.

This is quite true. Now whether you can observe anything in this universe from there, I'm not so sure.

Would finding the theory of everything rule out freewill.

originally posted by: bhaal
Would finding the theory of everything rule out freewill.

Well my immediate response would be to say no. But if you believe the theory of everything could explain everything in the universe we could find out free will is an illusion and everyrhing is already set. So not sure this question can be answered if your whole life is already mapped out along with everything that can happen. But I'd like to think the answer would be no.

why are these electrons referred to as EPR electrons?

phys.org...

are they proposing a spacetime tunnel like the EPR bridges i am somewhat familiar with from reading speculative physics books and articles and so forth? or is that not what they meant to imply by the label?