Ask a physicist anything. (5)

[Wiccan_Child]

Riddle me this! If I have a standard plug and a four-plug-socket extender, if I plug four more extenders into the original one, I will have a total of 16 free plug sockets.

Since there's no such thing as a free lunch, what happens? What of the original plug socket is constant, and is divvied up between the 16 connected sockets? Is it constant voltage but exponentially small current, or vice versa?

I've always wanted to know

 

[PintoBean]

You'll probably have a fire!

 

[PintoBean]

Is it possible to hear electro magnetic fields? I believe dogs can do it, so can humans do it too?

 

[Wiccan_Child]

Is it possible to hear electro magnetic fields? I believe dogs can do it, so can humans do it too?

The only EM sensing organ is the eye, and that detects photons with wavelengths of about 450nm to 750nm. Other photons in the EM spectrum, and large EM fields like magnets, are undetectable to humans - and, dogs too, I thought!

 

[PintoBean]

I was guessing about the dogs... Was watching Ghost Hunters. They brought a dog along and in every area of high EMFs the dog was uncomfortable. I assumed it was hearing.

 

[PintoBean]

Here's a scenario. If you are in a dark room- pitch black, can't see anything and a person enters but the person is absolutely silent! So none of the 5 senses are telling you that someone has entered the room, but you know that someone has. I'm not talking psychic, I'm trying to think scientifically. You sense someone is there. I was wondering if what triggered the feeling could be a change in the EMF of the room by the person's presence. And if it was a change in the EMF, how could one tell?

 

[Wiccan_Child]

I was guessing about the dogs... Was watching Ghost Hunters. They brought a dog along and in every area of high EMFs the dog was uncomfortable. I assumed it was hearing.

It was probably hearing a hidden dog whistle! It's unlikely that the soundsystem would be able to pick up that sound, making it a good way to make 'animal psychics' act uncomfortable. My iPad has an app that does the same thing, much to my cat's eternal chargrin

Here's a scenario. If you are in a dark room- pitch black, can't see anything and a person enters but the person is absolutely silent! So none of the 5 senses are telling you that someone has entered the room, but you know that someone has. I'm not talking psychic, I'm trying to think scientifically. You sense someone is there. I was wondering if what triggered the feeling could be a change in the EMF of the room by the person's presence.

Probably not, as there's nothing in the body that would be particularly affected by a change in the local EM field. Apart from the eyes, which have evolved to emit nervous impulses when hit with specific wavelengths, there's no body part that reacts noticeably to EM fields.

I suppose there could be a static charge to raise your hairs on end - you can certainly feel it when you put your arm next to a charged TV set (provided you have hairy arms, that is!), so if the person was spectacularly electrically charged, you might feel that. It'd be like standing next to a balloon.

But this would be easily detectable with equipment, and would discharge and spark frequently, if ghosts were doing it.

So, no, a change in the local EM field would engender anything that could be sensed by the body, unless it were so powerful that the very iron was siphoned out of your blood - in which case, ghosts are the least of your worries!

 

[chris4243]

Riddle me this! If I have a standard plug and a four-plug-socket extender, if I plug four more extenders into the original one, I will have a total of 16 free plug sockets.

Since there's no such thing as a free lunch, what happens? What of the original plug socket is constant, and is divvied up between the 16 connected sockets? Is it constant voltage but exponentially small current, or vice versa?

I've always wanted to know

The voltage is the same, and the current through the first socket increases -- but only to a point. The wires leading to the socket can only carry so much current (before getting dangerously hot, and the circuit breaker should shut it off to prevent a fire). Normally, what limits the current would be the resistance of the appliance plugged into the socket.

 

[chris4243]

Here's a scenario. If you are in a dark room- pitch black, can't see anything and a person enters but the person is absolutely silent! So none of the 5 senses are telling you that someone has entered the room, but you know that someone has. I'm not talking psychic, I'm trying to think scientifically. You sense someone is there. I was wondering if what triggered the feeling could be a change in the EMF of the room by the person's presence. And if it was a change in the EMF, how could one tell?

It's not by EM (other than light), because humans emit very little EM compared to things like your computer or cell phone that you can't sense.

 

[Chesterton]

I heard an astronomer on a TV show say that at certain times, if you're far from a populated area, you can tune in an AM radio between stations and hear little whistles and crackles which come from Jupiter's EMF.

YouTube - Jupiter sounds (so strange!) NASA-Voyager recording

 

[Wiccan_Child]

I heard an astronomer on a TV show say that at certain times, if you're far from a populated area, you can tune in an AM radio between stations and hear little whistles and crackles which come from Jupiter's EMF.

YouTube - Jupiter sounds (so strange!) NASA-Voyager recording

No way, that can't be the sound Jupiter makes... how cool! And oddly smoothly toned. Time to investigate I think.

 

[Assyrian]

Here's a scenario. If you are in a dark room- pitch black, can't see anything and a person enters but the person is absolutely silent! So none of the 5 senses are telling you that someone has entered the room, but you know that someone has. I'm not talking psychic, I'm trying to think scientifically. You sense someone is there. I was wondering if what triggered the feeling could be a change in the EMF of the room by the person's presence. And if it was a change in the EMF, how could one tell?

They will be radiating quite a lot of infra red, and making noise breathing and even their heart beat, which while you might not pick it up consciously as an audible sound we might still be aware of on an unconscious level. Probably more significant are smells, from their body, from warm clothes and from their breath. We may not be bloodhounds but smells are very good at working on a subconscious level triggering memories.

 

[mzungu]

Why does Tarzan not have a beard

 

[chris4243]

Why does Tarzan not have a beard

He shaves with Lord Greystoke's razor, after he was taught how by Phillippe.

 

[Tinker Grey]

What do you think of David Bohm's Guided/Pilot Wave Theory? (Broglie-Bohm)

 

[Gracchus]

He shaves with Lord Greystoke's razor, after he was taught how by Phillippe.

Nonsense! He started shaving with his father's hunting knife to keep from turning into an ape. This was long before he had ever seen any men outside of a picture book.
You must have got your idea from a movie, chris4243, or a comic book.

 

[Wiccan_Child]

What do you think of David Bohm's Guided/Pilot Wave Theory? (Broglie-Bohm)

I'm of the Copenhagen school of interpretation, so I spit and hiss at the pilot wave More seriously, I'm just not convinced the concept of a 'wave' is a valid one. Mathematically useful, sure, but it's particles all the way down!

 

[chris4243]

What do you think of David Bohm's Guided/Pilot Wave Theory? (Broglie-Bohm)

Me, I subscribe to the "shut up and calculate" interpretation of quantum mechanics.

 

[Steffenfield]

3 dimensional math question here...

Okay, when I was much younger, I made a cute airplane dog fighting game on my Commodore 64.

Think super old school.

Now, in this game, obviously I was very limited in some of the physics involved.

Both planes could only fly in 8 directions. (Up, Down, Left, Right, Up Left, Up Right, Down Left, Down Right)

Instead of showing actual ammunition being fired between the two planes, which made the game run super chunky (I programmed it in BASIC), I opted to generate a simple formula.

I found that if you subtracted the two memory locations on the screen (1024 - 2048 I think) of both the planes and then divided it by the plane's direction (-39, -40, -41, -1, 1, 39, 40, 41).... If that result was a whole number, this would be that the one plane had the other directly in it's site.

Obviously if the plane was going horizontal (-1 or 1), it would always produce a whole number in my equation so I had to tweak my formula just a titch.

Sorry for the ramble.

Anyway. Nutshell time.

Take the two memory locations of both planes and subtract them, divide that by the direction of one of the planes, if the number is whole (with a horizontal exception), you can calculate if the other plane is in direct fire with the first one.

With that being said, could such a formula be generated in 3 dimensional space?

So say you have an object somewhere.

You have another object someplace else pointing in a certain direction.

Can you create a formula to see if that second object's direction is in perfectly direct site to the other?

If so, what are all of the number's or variables required for this?

If possible, could you provide a simple math example?

Thanks!

I super wuvs this thread!

 

[Steffenfield]

^ Obviously you would need GPS numbers and also elevation locations as well, but I'm confused about the 3 dimensional direction of the object that's pointing to the other.

I don't know.

Hopefully I made some sense on my previous post.

Since yeah, most of my posts have no sense. *lol*