I bet you didnt know that

America was names after Amerigo.

But they wanted it to end in A Cos the other continents did (cept europe)

Sounds mad

^^ Obvious limitations of 3D world's equivalent displayed on 2D surface.

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

The worlds first ever plane with no moving parts has recently completed a 60m test flight. It's not exactly a 747, it weighs under 3kg! but still, powered flight with no moving parts is no small feat.
It uses a technology called ionic wind - basically electrically charged particles are generated and as they are pulled towards an oppositely charged wing they push the air over it and provide lift in the same way as air passing over the 747's does.
The wright brothers first flight was a mere 37m

Sir John Lade was the first man to appear in public wearing long trousers.

Both Charles Darwin and Einstein got married to a first cousin.

Einstein's wife was so related she was both his first cousin and second cousin!

Carry wrote: »

Maybe someone can explain why iron files show this magnetism field? For blondes? :cool: :pac:

Well I'll try. Pack as much in as possible.

Electric and Magnetic Fields:
Electric and Magnetic fields are just two facets/faces of the Electromagnetic field. As I said above, depending on your speed a given Electromagnetic field can appear as an Electric field, a Magnetic Field or sometimes you'll see two fields, one Electric and one Magnetic. However there is always only one field, it just appears different to different observers. An electromagnetic field can either be generated and centered on a piece of matter or just moving freely on its own. If moving freely on its own, it's what we call light. If attached to matter, it behaves differently depending on the matter that generates it, i.e. how much charge the matter has, in what direction and how fast the matter is moving.

So keeping that in mind the main difference between an electric field and a magnetic field is how they move nearby objects that are electrically charged. On a basic level, an electric field will either pull them toward a point or push them away from a point. By convention we use what they do to a positive charge when we draw them:

So the above image just shows that the electric field from a positive charge will push away other positive charges and the field of a negative charge will pull in positive charges. These are the most basic type of electric field and are called monopole fields.

The field made by a positive and negative charge will look like this:


So positive charges will be pushed away from the big positive charge on the left and pulled toward the negative charge on the right. This type of electric field is called a dipole field.

Magnetic fields are similar except:

1. We say North and South for their two charges, not positive and negative. Just like you have to be electrically (i.e. positive or negative) charged to respond to an electric field, you have to be magnetically charged to respond to a magnetic field. For magnets we usually say "moment", not charge.
2. They can't have monopole fields, because North and South always occur in pairs*. You never get North on its own like you get Positive charge on its own, it's always North and South. We know why this is, but I can't think how to explain it briefly enough to be tolerable.

Magnetic dipoles look just like Electric dipoles above:


Things at our scale are rarely magnetically charged because the Norths and Souths of our atoms don't line up correctly and cancel each other out. Electric charge is much more common at our scale because a positive charge can be created without there necessarily being a negative charge created with it, so they tend not to cancel as easily.

An Iron filing simply has all of its atoms aligned so that the North and Souths don't cancel and so the filing as a whole has a magnetic moment and can respond to the field of a magnet nearby. The shape traced out by the filings is just the dipole field shape in the image above.

Spin and Magnets:
So what makes the North and South charges in an atom?

First of all charges that are rotating in an orbit can make a North and South. If you think of the Nucleus like the Sun and an electron like the Earth:

Then the electron acts like the North on one end of its orbit and then swings down to act like the South on the other end.

The electron is also rotating in another way, not to do with spinning around the nucleus, but more like rotating on its axis, like how the Earth rotates over the course of a day. This also makes a North and South, as when it faces one way it's North and then it spins round to face the other way and it's South.

However this is only a picture for the ease of the human mind. Whatever is really going on, the electron doesn't really spin for the reasons I mentioned in the last post, it's just that you can pretend it does for most purposes.

There are various theories as to what is going on and we have narrowed them down to only a few possibilities, but they are all very very weird. I think I haven't gone too weird in this post so if you don't want your head wrecked, I'd stop here.



*Wormholes, if they exist, can make magnetic monopoles, i.e. they can be just North. This would be one way of detecting them. Also wormholes emit massive amounts of radiation. So the team in Stargate SG-1 would actually be flayed alive by the enormous North magnetic charge of the wormhole mouth ripping their atoms out of their bodies, if not melted by gamma radiation.

ohnonotgmail wrote: »

Somebody else was watching Only Connect then.

first time watching it. very difficult show. One guy was an absolute freak. Amazing ability to make the connections.

mzungu wrote: »

Cruise ships have morgues on board.

Roughly about 200 people due every year on cruises so most large ships will have morgues with capacity for up to 10 bodies.

Absolutely love this. If I was going on a cruise I would make it known to my traveling party as well as the captain that I want to be buried at sea. How cool would it be for 1000s of passengers standing to attention singing amazing grace as I was jettisoned into the deep blue sea followed by a 21 gun salute. Now that is rock and roll.

NIMAN wrote: »

.... and with it usually being all inclusive drinks on a cruise, all the travellers can throw you the biggest wake ever.

Party like it's 1999, what a way to send you off

Well this gets ducking better. I would direct that each guest would have to drink at least 10 scotch’s and play bingo before the ceremony. Perhaps a karaoke contest after finishing up with an all out titanic themed dancing night. This would be the most epic send off ever and beats most modern funerals hands down.

Fourier wrote: »

Well I'll try. Pack as much in as possible.
(...)

Thank you Fourier, this is fantastic! You would make a brilliant teacher, or maybe you are.

It get's really interesting with your "spoilers", the different theories. It leads into philosophical realms. But I think all sciences, or at least their interpretations by humans, touch philosophy.



I now have an incentive to read finally that book that is sitting on my bedside table for ages: "Reality is not what it seems - The Journey to Quantum Gravity" by Carlo Rovelli.

joeguevara wrote:

Absolutely love this. If I was going on a cruise I would make it known to my traveling party as well as the captain that I want to be buried at sea. How cool would it be for 1000s of passengers standing to attention singing amazing grace as I was jettisoned into the deep blue sea followed by a 21 gun salute. Now that is rock and roll.

Rock and roll ?? Where's the TV through the window, the coke, the hookers

Pretty sure the likes of Aviva stadium and Croke Park if they don't have a morgue as such have at least a dedicated cold room on stand by.

mikhail wrote: »

I read his 7 Brief Lessons on Physics recently. The lad can write.

7 Brief Lessons is a bit odd. Rovelli presents points as true (such as particles popping in and out of existence) that he himself knows aren't true as he explicitly says so in his own scientific papers. He also talks about how the world is made of particles and fields obeying objective laws, even though his personal explanation/interpretation of QM (see here) is explicitly about there being no objective laws or even properties and the idea of things being made out of particles is impossible in light of what we know now (due to results like Haag's theorem and Malament's theorem), which again Rovelli knows.

"Reality is not what it seems" is quite good, especially the sections on the philosophy and history of physics, though the scientific sections have similar errors to 7 brief lessons.

Fourier wrote: »

the idea of things being made out of particles is impossible in light of what we know now (due to results like Haag's theorem and Malament's theorem)

Jaysus Fourier, you've lost me again!

What do you mean things aren't made of particles? What are they made of?

sbsquarepants wrote: »

What do you mean things aren't made of particles?

Basically although particles are a useful way to talk about the results of some experiments (not all), they aren't really what's present. There are theorems (Haag's and Malament's) that show that the particle picture is only useful in certain situations.

sbsquarepants wrote: »

What are they made of?

Nobody knows, there is currently serious disagreement. Again I leave the head wrecking stuff in spoilers.