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tdn
2004-Mar-23, 10:33 PM
OK, this is going to sound really stupid, but it's nagging at me...

Suppose I travelled to an extremely remote part of the universe, where gravity from nearby objects is negligible. And suppose that until I complete the task described below, I can turn off gravity.

I then place a metal block, say a 6 inch cube, in front of me. Six inches away from it I place another block, and six inches from that another. I continue until I have a row of blocks perhaps a million miles long, with a distance of six inches between each. I then make another row six inches from that, and continue making more rows until I have a million miles of columns. I then put more blocks on top of those, so that I have a cube-like arrangement.

Then I step away and turn gravity back on.

What will happen to my blocks, and how soon?

What if I used other materials, such as stone? Wood? Helium balloons? Water balloons?

Told you it was a weird question. But I'm serious.

Drakheim
2004-Mar-23, 10:43 PM
I then place a metal block, say a 6 inch cube, in front of me. Six inches away from it I place another block, and six inches from that another. I continue until I have a row of blocks perhaps a million miles long, with a distance of six inches between each. I then make another row six inches from that, and continue making more rows until I have a million miles of columns. I then put more blocks on top of those, so that I have a cube-like arrangement.

Then I step away and turn gravity back on.

What will happen to my blocks, and how soon?

Err, the blocks would pull themselves together to form a rather large cube. As for the time it would take.. Not very long at all if the radius was over 1 million miles. Maybe a few months?


What if I used other materials, such as stone?

Same as above.


Wood?

Same as above but with the possibility of it catching fire from the compression that would occur.


Helium balloons?

They'd explode :P Tis a vacuum out there :lol:

But if the material could hold the balloons together, they would also form a structure and become a mini gas planet after the pressure burst the balloons.


Water balloons?

Same with the above, would most likely form an ice planet or comet.

tdn
2004-Mar-23, 11:52 PM
[quote]Err, the blocks would pull themselves together to form a rather large cube.

Really? Not a ball? And wouldn't the interior of the structure heat up a great deal?

ToSeek
2004-Mar-24, 12:56 AM
My thought was that if the blocks were made up of some sort of material that could undergo fusion you'd likely end up with a small star. But I daresay the computations to demonstrate that are pretty complicated.

Normandy6644
2004-Mar-24, 01:53 AM
[quote]Err, the blocks would pull themselves together to form a rather large cube.

Really? Not a ball? And wouldn't the interior of the structure heat up a great deal?

The interior definitely would heat up because of the pressure, but it wouldn't form a ball unless it were under some central force. The outer structure might begin to pull in on itself, but assuming the blocks were made of a non-stretchable material, I think they would remain blocks.

JohnOwens
2004-Mar-24, 02:32 AM
Err, the blocks would pull themselves together to form a rather large cube.
Really? Not a ball? And wouldn't the interior of the structure heat up a great deal?
The interior definitely would heat up because of the pressure, but it wouldn't form a ball unless it were under some central force. The outer structure might begin to pull in on itself, but assuming the blocks were made of a non-stretchable material, I think they would remain blocks.
"Some central force" like gravity, perhaps? Remember, we're talking about a cube half a million miles on a side. Remember the discussion about planets vs. planetoids vs. asteroids, and how without exotic materials, things will pull themselves into spheres at something a bit under 1,000 miles diameter (I could be wrong, might be km). Remember this thing will have a mass around 5*10^29 kg times the specific gravity of steel (or whichever material you choose for the blocks).
Now that I think about it a bit more, I guess "non-stretchable material" sounds like the "exotic materials" I mentioned. But the OP mentioned specific materials, none of which are that exotic.
Otherwise, you could easily make a hollow Moon out of titanium. :wink:

Normandy6644
2004-Mar-24, 01:40 PM
Yeah, but don't forget the Roche limit, defined as "the orbital distance at which a satellite with no tensile strength (a "liquid" satellite) will begin to be tidally torn apart by the body it is orbiting." In other words, if the center blocks were more densely packed (producing some kind of "core" I suppose) then some of the outer objects, depending on the strength of the field, wouldn't be able to stay solid. I'm not exactly sure how else this would affect the cube, but I think it factors in somewhere.

tdn
2004-Mar-24, 05:43 PM
My thought was that if the blocks were made up of some sort of material that could undergo fusion you'd likely end up with a small star. But I daresay the computations to demonstrate that are pretty complicated.

This is the crux of my question. Under extreme heat and pressure, would the chemical makeup of the blocks hold up? Let's say that the blocks are made of ice. That's a bit of oxygen, and twice as much hydrogen. Isn't there star potential there?

So what if I wanted to turn the blocks into a star -- what should the blocks consist of?

xbck1
2004-Mar-24, 06:45 PM
What if the blocks stretched into infinity, wouldn't they jush hang there if they were perfectly symmetrical?

Andreas
2004-Mar-25, 02:52 AM
What if the blocks stretched into infinity, wouldn't they jush hang there if they were perfectly symmetrical?
Technically yes. But I think some ever so small quantum fluctuations would cause infinitesimal imbalances which would eventually cause gravitational collapses of parts, causing galaxies of molten cube stars to be formed.

Doesn't matter that there may be no fusion from steel cubes, the heat created from the collapses should create "stars" glowing a long time until they finally radiate away their heat. 8)