Science

[johnnyrod]

Well, it doesn't need energy cos that is defined by Newton as the product of a force and the distance it moves. It sits still on your fridge so therefore it doesn't do any work.

This is wher ei look stupid, cos if I understood magnetism one day I've forgotten it all now. Usually these things are all related to atoms or microscopic structures with unbalanced charges. The electrons are out to get you again.

[cassiopeia]

Originally posted by Yapaluna
Hi, all you scientistst in the world!

I have one question which nobody I asked until now could answer.

Where does the power of magnetism come from? How can this piece of iron stick to my refrigerator years and years without falling down? Against gravity?

Where does the energy come from?

All matter is made up of atoms, which are in turn made up of protons, neutorns and electrons. Protons and neutrons are clumped in the middle of an atom, while electrons move around the outside. (It's actually more complicated than that, but we'll stick with that explanation.) Atoms with extra electrons are negatively charged, and those that lose electrons are positively charged. Some objects, like iron, are naturally magnetic -- you can picture iron as having lots of little magnets, each with a north and south pole, aligned in the same direction. So iron is magnetic. Like repels, opposites attract, so the iron is attracted to the fridge because one has a south pole and the other has a north pole.

I suppose the energy comes ultimately comes from the electrons. Gravity is actually the weakest of the four forces (electromagnetic, strong, gravity and weak are the four know forces of nature.)

Hope this helps!

[The Gaffer]

Originally posted by johnnyrod
Well, it doesn't need energy cos that is defined by Newton as the product of a force and the distance it moves. It sits still on your fridge so therefore it doesn't do any work.

It has to do work so as not to fall down; it has to work against gravity.

This is one of the things that's great about science. Whenever you answer one question about ten others immediately pose themselves. I've always been baffled by magnetism: how does it work?

Clearly, we can see that it does, and we can make use of it and enjoy it (anyone seen the aurora?), but HOW does it work?

[Beor]

It has something to do with electric-magnetic force, which is one of the four forces (gravitational force, strong nuclear force, e-m force, and weak nuclear force), but I dont really remember what it is. I could narrow it down for you though. Gravitaional force is obvious, Strong Nuclear force is the force that holds the nucleus of an atom together, and weak NF is the force that pushes them apart (i think it has been awhile. E-M force has to do with different charges on electrons, which are defined by their spinning motion (I think, dang it has been a while. Time to go back to Paul Davies), so it all...man, never mind, I just realized that I think I'm smarter than I am. Someone help me please

[Yapaluna]

It´s always a good feeling to be not alone. Perhaps someone with better english could post this question at the h2g2 site which was started by Douglas Adams?

Thanks anyway for all who tried to answer.

[Earniel]

Originally posted by cassiopeia
It sounds good. By the same people who made "Walking With Dinosaurs" I suppose. I can't wait till they show it here. I also love any documentaries presented by David Attenborough or Robert Winston.

Oh it's very good, it's about a visit to the seven most dangerous seas since the beginning of the earth. Expect lots of teethy critters. Though it is taken a tiny weeny over the top at some points IMO. Still, I enjoyed it a lot.

David Attenborough has got quite an impressive list of documentaries as well. I can't seem to remember Robert Winston, though. Can you give me a few titles of documentaries? They might ring a bell.

[cassiopeia]

Originally posted by Eärniel
David Attenborough has got quite an impressive list of documentaries as well. I can't seem to remember Robert Winston, though. Can you give me a few titles of documentaries? They might ring a bell.

Robert Winston has done series such as The Human Body, The Secret Life of Twins and Superhuman. I believe he's a professor specialising in fertility.

[BeardofPants]

He's nutty. I remember watching the Human Body, and he was drinking alcohol to demonstrate how the body reacts intoxicated. Heehee.

[Lizra]

I saw that. I kept saying "oh no!" All sorts of unpleasant things happened!

I taped all of David Attenborough's "Life on Earth" series in the early eighties. Thought I was really doing something! Those old VCR's are horrible quality now. Did he just do the one about "The Blue Sea", or something like that. I tried to watch it, but my whining kids ruined it!

I really liked that semi dramatized one about Neanderthals. I remember one about lava, that had this incredible footage of this old couple, in a special boat on a lava lake or something, they later were killed filming another volcano.
The "history" docu's can get pretty ridiculous....with the poorly dramatized reenactments, or those ones about earthquakes that show a shot of the seizmograph (sp) needle shaking, about 500 times. BORING!

[HOBBIT]

hey, i've always wondered, what do our pigments in our skin do?

I know that pigments absorb light and all, but does it work the same way in humans?

I'm refering to freckles mostly - what exactly is their purpose? I've accidently ripped a few off in my life, what effect does this have on me?
--

biology not too fun . did well in the evolution unit (thanks to the moot ), but the other parts are not as fun.

i definitely don't want to do anything science related.

[Nurvingiel]

I love plant biology! I know a decent amount in this field, and basic chem, physics, and other types of biology.

I'm in Forestry, so ask me anything about trees! I love trees.

[Insidious Rex]

uh... well as to your question about pigments we have them to protect us from sun and ultraviolet rays. thats why people who come from hot areas like africa tend to have dark skin and dark hair. light skinned blondes are at a disadvantage on the open plain so a pigment shield is evolutionarily beneficial. we know this is true because dark skin has evolved over several continents seperately based on the climate.

[BeardofPants]

Yep, and dark skin doesn't fare well in cold climates. That's due to the fact that there is less UV exposure, and dark skin is adapted to take in minimal UV, whereas light skin is adapted to take in a lot more... This is probably why there were initially a significant number of cases of rickets in hominids (generally young/old) that migrated from hot African climates, to the cooler climates of Europe from 200,000 BP onwards.

[Beor]

Exactly, which is why I have such a hard time in the desert. I'm from Minnesota, with ancestors who were from Norway and Sweden, my blood is too thick for the desert (and the skin was too white, but the sun will getcha if youre not careful)

[Janny]

This thread is to discuss science, ask questions about science. Specifically, biology, chemistry, and geology.

As a 'physicist' and 'mathematician' (ie. 16 year old student of) I'm gravely insulted by your definition of science.
What are the underlying principles behind science ie. studies into the world which are quanitifiable?

[Nerdanel]

I'd LOVE to start studying biology (more specifically zoology)! I hope I'll make it to the university.

I love biology, geography and maths. But I can't come up with any questions now - I'm studying psychology for my A-levels. That's OK too.

[Nerdanel]

Originally posted by BeardofPants
He's nutty. I remember watching the Human Body, and he was drinking alcohol to demonstrate how the body reacts intoxicated. Heehee.

I saw a documentary with him (Robert Winston) half an hour ago. He had to go down in a cage in the water with some hugry, eating sharks to demonstrate which part of the brain reacts on fear.. He's cool

But Sir David Attenborough is even cooler. I love his documentary on mammals.

[ayarella]

"As a 'physicist' and 'mathematician' (ie. 16 year old student of) I'm gravely insulted by your definition of science.
What are the underlying principles behind science ie. studies into the world which are quanitifiable?"

Science encompasses so many things! For example, computer science- a science that utilizes components of chemistry, physics ect. And something which I know nothing about I choose to start this thread to discuss fields of science which I am actively interested in (and taking classes in at the university currently). Chemistry is the fundamental science behind EVERYTHING else! It is truly amazing.

[Janny]

But chemistry is the hardest to learn! Damn Le Chatalier!
And what about physics? Doesn't that underpin chemistry in that the tiny things claimed by physicists make up the slightly-less-tiny-but-still-tinsy-wincy thingys claimed by chemists?

[ayarella]

Yes, definitely. Physics is the fundamental force in chemistry on that tiny scale (what holds an atom together). And those tiny little particles that they discovered that no one seems to understand