Gravity

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Oct 25, 2006
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Originally posted by: Eeezee
Originally posted by: gururu2
black holes do not spin afaik and they emit immense gravitational fields. i bet that is something you knew!

Black holes can spin, there is observational evidence suggesting that there are some spinning black holes (with smaller event horizons)

I thought all black holes spun at an incredibly fast pace. At higher than Pulsar speeds.
 
Aug 10, 2001
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Originally posted by: legoman666
Originally posted by: Random Variable
Originally posted by: ForumMaster
Originally posted by: torpid
Well, to be fair, you can simulate gravity by having people stand inside of a sphere or cylinder that is spinning.

true, but then the simulated gravity is the centrifugal force. every object has a gravity field. take for example, an astronaut. if there was no stronger field of gravity in his vicinity, his tools would be attracted to him due to his field of gravity.

Every object with mass is attracted to every other object with mass.

I'm trying to think of an elegant way to say that's why your mom is attracted to my penis without sounding crude but I came up blank.
Stop pretending to have a penis.

 

Inferno0032

Golden Member
Mar 26, 2007
1,107
0
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Originally posted by: ForumMaster
Originally posted by: torpid
Well, to be fair, you can simulate gravity by having people stand inside of a sphere or cylinder that is spinning.

true, but then the simulated gravity is the centrifugal force. every object has a gravity field. take for example, an astronaut. if there was no stronger field of gravity in his vicinity, his tools would be attracted to him due to his field of gravity.

I was waiting for someone to say something about centrifugal force, there really is no such thing, more of a concept. It is still only the centripetal force holding you in the circular motion, however, the feeling that we are being "pushed" into the wall is what we refer to as centrifugal force, and, in fact, doesn't exist, as the only thing making us feel like we are going into the wall is inertia, and inertia is not a force.
 

Born2bwire

Diamond Member
Oct 28, 2005
9,840
6
71
Originally posted by: Inferno0032
Originally posted by: ForumMaster
Originally posted by: torpid
Well, to be fair, you can simulate gravity by having people stand inside of a sphere or cylinder that is spinning.

true, but then the simulated gravity is the centrifugal force. every object has a gravity field. take for example, an astronaut. if there was no stronger field of gravity in his vicinity, his tools would be attracted to him due to his field of gravity.

I was waiting for someone to say something about centrifugal force, there really is no such thing, more of a concept. It is still only the centripetal force holding you in the circular motion, however, the feeling that we are being "pushed" into the wall is what we refer to as centrifugal force, and, in fact, doesn't exist, as the only thing making us feel like we are going into the wall is inertia, and inertia is not a force.

http://xkcd.com/123/
 

Jeff7

Lifer
Jan 4, 2001
41,596
20
81
Damn man....I knew the basics of nuclear fusion and how the sun worked when I was in elementary school.
 

Inferno0032

Golden Member
Mar 26, 2007
1,107
0
71
Originally posted by: Born2bwire
Originally posted by: Inferno0032
Originally posted by: ForumMaster
Originally posted by: torpid
Well, to be fair, you can simulate gravity by having people stand inside of a sphere or cylinder that is spinning.

true, but then the simulated gravity is the centrifugal force. every object has a gravity field. take for example, an astronaut. if there was no stronger field of gravity in his vicinity, his tools would be attracted to him due to his field of gravity.

I was waiting for someone to say something about centrifugal force, there really is no such thing, more of a concept. It is still only the centripetal force holding you in the circular motion, however, the feeling that we are being "pushed" into the wall is what we refer to as centrifugal force, and, in fact, doesn't exist, as the only thing making us feel like we are going into the wall is inertia, and inertia is not a force.

http://xkcd.com/123/

Well done! +1 for you on your interwebz skillz
 

Born2bwire

Diamond Member
Oct 28, 2005
9,840
6
71
Originally posted by: Inferno0032
Originally posted by: Born2bwire
Originally posted by: Inferno0032
Originally posted by: ForumMaster
Originally posted by: torpid
Well, to be fair, you can simulate gravity by having people stand inside of a sphere or cylinder that is spinning.

true, but then the simulated gravity is the centrifugal force. every object has a gravity field. take for example, an astronaut. if there was no stronger field of gravity in his vicinity, his tools would be attracted to him due to his field of gravity.

I was waiting for someone to say something about centrifugal force, there really is no such thing, more of a concept. It is still only the centripetal force holding you in the circular motion, however, the feeling that we are being "pushed" into the wall is what we refer to as centrifugal force, and, in fact, doesn't exist, as the only thing making us feel like we are going into the wall is inertia, and inertia is not a force.

http://xkcd.com/123/

Well done! +1 for you on your interwebz skillz

I've found that xkcd holds many answers to life.
 
Mar 10, 2005
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Originally posted by: Analog
Originally posted by: The Boston Dangler
Originally posted by: gururu2
black holes do not spin afaik and they emit immense gravitational fields. i bet that is something you knew!


black holes spin incredibly fast. they also emit muon lasers (maser) at at least one pole. afaik, the energy and mass of the maser does not come close to the energy and mass being eaten by the black hole.



A Maser is a Microwave Laser, and they don't emanate from inside the black hole, as even light cannot escape its gravity, but from the disc of superheated gas that is falling into the black hole.
See below:

i don't know where i got muon from...

if the maser is produced by, and perpendicular to the rotating axis of, the accretion disk, then what is the beam i've seen projected from the poles? or is that just a line through the axis of a sphere?

edit:
classical or fancy, which is correct?
 

ForumMaster

Diamond Member
Feb 24, 2005
7,792
1
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Originally posted by: Random Variable
Originally posted by: ForumMaster
Originally posted by: torpid
Well, to be fair, you can simulate gravity by having people stand inside of a sphere or cylinder that is spinning.

true, but then the simulated gravity is the centrifugal force. every object has a gravity field. take for example, an astronaut. if there was no stronger field of gravity in his vicinity, his tools would be attracted to him due to his field of gravity.

Every object with mass is attracted to every other object with mass.

umm, yeah. that's what i said.
 

Fritzo

Lifer
Jan 3, 2001
41,920
2,161
126
Gravity is a cool concept. Any object with mass is going to "press" on the fabric of space/time. The more mass an object has, the more of a dimple it's going to make in the fabric. This indentation the object makes is gravity.

Here's a good example: Place a bowling ball on a bed. See how it makes a crater around it? Now, place a pea near the bowling ball, and it will fall toward it. Gravity works in a very similar way.

 

DrPizza

Administrator Elite Member Goat Whisperer
Mar 5, 2001
49,601
167
111
www.slatebrookfarm.com
Originally posted by: Random Variable
Originally posted by: ForumMaster
Originally posted by: torpid
Well, to be fair, you can simulate gravity by having people stand inside of a sphere or cylinder that is spinning.

true, but then the simulated gravity is the centrifugal force. every object has a gravity field. take for example, an astronaut. if there was no stronger field of gravity in his vicinity, his tools would be attracted to him due to his field of gravity.

Every object with mass is attracted to every other object with mass.

Electrons have mass. They're repelled by other electrons :)
Sure, the gravitational force of attraction can be calculated between them, but it's quite pathetic compared to the other forces. (Just being picky.)
 

Fritzo

Lifer
Jan 3, 2001
41,920
2,161
126
Originally posted by: DrPizza
Originally posted by: Random Variable
Originally posted by: ForumMaster
Originally posted by: torpid
Well, to be fair, you can simulate gravity by having people stand inside of a sphere or cylinder that is spinning.

true, but then the simulated gravity is the centrifugal force. every object has a gravity field. take for example, an astronaut. if there was no stronger field of gravity in his vicinity, his tools would be attracted to him due to his field of gravity.

Every object with mass is attracted to every other object with mass.

Electrons have mass. They're repelled by other electrons :)
Sure, the gravitational force of attraction can be calculated between them, but it's quite pathetic compared to the other forces. (Just being picky.)

That's because electromagnetic force > gravitational force. The force is weak in gravity.