Timbo

Two (or more) adjacent objects attract each other due to the forces of gravity between them. So, are there any objects on the Earth that are massive enough to attract each other ? (Ignoring the Earth's attraction, I'm looking for an attraction between the objects only.) For example, if two supertankers approached each other at sea, and then stopped, would the force of gravity between them be sufficient to cause them to come together ? Or would two skyscrapers be massive enough to influence each other ?

I guess what I'm really asking is, what is the smallest object on Earth that can cause a measurable gravitational attraction on another object, ignoring the attraction from the Earth itself ?

As light is already travelling at the speed of light, is there any way to use light itself to accelerate a mass up to the same speed ? I'm pretty sure I know what the answers are going to be, but it seems like a possibility that's worth investigating !

This is something I've been pondering over for years!

Is it possible to magnetize a steel ball, say a 1/2" diameter ball-bearing, so that all the 'North' poles act outwards from the surface and all the 'South' poles act inwards towards the center ? And if it could be done, would it act like a magnetic monopole ? What would it do, how would it behave in the presence of other magnetic fields ?

I'm thinking specifically about light or electromagnetic 'waves' here, but the same question could apply to sound, water etc. If energy cannot be destroyed, and yet the two waves appear to cancel and effectively disappear, where has the energy gone to ? Or do they not really cancel in the first place ?

I'm a professional embedded software engineer, but so far I haven't had any experience of writing DSP software. If anyone can recommend a good introductory book, especially including digital filter design, I'd appreciate it.

Current theories suggest that entangled particles can influence each other even if separated by vast distances in three dimensions. Is it possible that, although they are far apart in 3 dimensions, they are actually really close or even at the same point in the 4th and/or higher dimensions and thus can influence each other easily through those extra dimensions ? If you accept time as being the 4th dimension, then no matter how far apart two particles are in the first 3 dimensions, if they exist at the same time they are both at the same point in the 4th dimension.

I saw the gig on BBC4 recently, with Nanci Griffith, Mary Chapin-Carpenter and Rosanne Cash. Wow! I think it was from 1992, but the show was excellent. Now I'm trying to get a copy on CD, or even video if it's not available on CD, but I can't find it anywhere ! Does anyone have any idea where I can get a copy ?

I saw the gig on BBC4 recently, with Nanci Griffith, Mary Chapin-Carpenter and Rosanne Cash. Wow! I think it was from 1992, but the show was excellent. Now I'm trying to get a copy on CD, or even video if it's not available on CD, but I can't find it anywhere ! Does anyone have any idea where I can get a copy ?

Are they relatively close for their size, or relatively far apart ? And what makes up the space in between ?

Or, do we mean that all the elementary particles that make up the universe are expanding in size as well?

In other words, are all the stars and galaxies flying away from each other, while the particles that they are made from are staying the same size and distance from each other - and hence the universe is becoming more 'diluted', OR, is it just that all the stars and galaxies are staying the same relative size and its the elementary particles that are expanding - and hence the universe is not becoming 'diluted'?

Say, pictures taken by the Voyager space probes etc ?

Why ? I can lift an object, say a small stone, straight up at say 3cm/sec with very little effort. Hypothetically, if I kept on applying the same amount of effort the stone would continue to rise until it eventually left the Earth's atmosphere, right ? So the stone left the Earth but travelling at only 3cm/sec. If this is correct, surely the same principle could be applied to a much larger object, say a space shuttle or space station ? Obviously the amount of effort required would be greater, but the shuttle could still leave the Earth at a much lower speed.

Why is the universe so large, and the stars and planets so far apart, that we can almost never expect to reach even the nearest star ? What's the point of it all, it must be there for a reason ?

Is it possible to see the site where Apollo 11 landed using a very large telescope from Earth ? That would put an end to all the conspiracy theories once and for all !