BBC Horizon 2008: 1/5 What on Earth is Wrong with Gravity

Particle physicist and ex D:Ream keyboard player Dr Brian Cox wants to know why the Universe is built the way it is. He believes the answers lie in the force of gravity. But Newton thought gravity was powered by God, and even Einstein failed to completely solve it. Heading out with his film crew on a road trip across the USA, Brian fires lasers at the moon in Texas, goes mad in the desert in Arizona, encounters the bending of space and time at a maximum security military base, tries to detect ripples in our reality in the swamps of Louisiana and searches for hidden dimensions just outside Chicago.

Category:

Science & Technology

Tags:

• Particle Physics
• Brian Cox
• Gravity
• Universe
• string theory
• quantum physics
• multiverse
• hidden dimensions
• space and time

[schwarzfalk]

this guy's supposed to be 40 in this vid yet he looks like he's fresh outa college...WTF???

[callawaydekluizen]

@ALPHADESIGNTAMPICO the ball moves in a straight line but because he is folowing that curve he makes circles. That s your attraction. If the speed of the ball is fast enough to break through the curvs, it keeps going at a straight line, hope that helps you visuallizing it :)

[callawaydekluizen]

@ALPHADESIGNTAMPICO look at it like this. take a large towel and hold it with 2 people on each side in the air so the towel is horizontal. The towel is your 'spacetime'. Now put a mass in the middle of the tower. If the mass is heavy enough the towel will show a dent because of the weight. This is the curving and bending of spacetime. Now try to roll a ball in a straight line past the object in the middle. You see that the ball 'folows' the curves and this circles around the object in the middle

[ALPHADESIGNTAMPICO]

@callawaydekluizen Hipoteticaly situation. Just to understand how gravity would work. 

[callawaydekluizen]

@ALPHADESIGNTAMPICO not possible, everything is moving you can never have a "freeze"

[beatboxpeej]

@ALPHADESIGNTAMPICO the asteroid will be attracted by the biggest planet since it has more mass and gravity makes objects (and even energy) move toward the biggest object since it's influence is greater. The only exception would be if the asteroid is closer to the smaller planet. Gravity has greater effects on objects when you are getting closer to the "source" of gravity.

[ALPHADESIGNTAMPICO]

@beatboxpeej Thanks! But assuming that one planet is bigger than the other and no one of the 3 objects is moving, what should happen?

[beatboxpeej]

@ALPHADESIGNTAMPICO It depends on the mass of the two planets, the velocity of the asteroid (if any) and the motions of the planets. Assuming absolute equality of the masses, no motions at all of all 3 bodies..then nothing will ever move. You would put a sheet of paper on a side of the asteroid and it would move towards the opposite side.

Yo no hable espanol..but I speak french and french is close enough I could understand most of your question

[paigerocks884]

hey,he's just happy about physics!

[ALPHADESIGNTAMPICO]

si tengo 2 planetas separados uno mas grande que el otro y coloco un asteroide justo en medio de los 2 hacia donde se ira el asteroide?!