OT?: Goodbye to an era

If it is big enough to shatter it when the goal was a push, then the shattering is enough to also move the entire mass, shards and all, just as desired.

And what of the swarm on the next orbit?

Shattering won't move the mass off a collision course. All it would achieve would be lots of impacts scattered over a larger area possibly causing even more damage than a single impact.

Looks to me I dropped a triplet of zeroes here. I meant to say

I think we can agree than a nuke can move a lot of rock, fast.

John

They were probably talking about the Bikini atoll, and the big blast nuclear detonation project there was the Castle Bravo one. The result was actually a 2 km diameter 75 meter deep crater. This was USA's largest nuclear explosion. Only 4 larger ones are noted, all accomplished by USSR.

To warm from 20 C to 100 C and to vaporize, at combined 620 calories per gram (from memory without looking up in quite a while), while nuclear weapon yield statements assume that a gram of "high explosive equivalent" or "TNT equivalent" is 1000 calories per gram (regardless of the actual value for TNT)...

That means 1.613 E6 metric tons water vaporized per megaton dissipated into water with 100% dissipating into water successfully evaporated and none dissipated into any parcels of water beyond what is necessary to achieving vaporization. Sounds close enough to me!

I do seem to slightly recall that the requirement for rock is closer to per-same-volume than to per-same-mass in comparison to water... Looks like my 2,512 cubic meter is almost 3 orders of magnitude smaller in volume than what megaton could theoretically vaporize, and I seem to like to think that the actual result would be closer to 2 orders of magnitude smaller. Even considering 49% of the energy reaching the target area, some of that being reflected or reradiated, and some of what's left going where it falls short of achieving vaporization, and some of what remains going into kinetic energy in the vapor and shrapnel (which is useful).

And, 1 megaton is only "fairly large". And the number of nuclear bombs to use against the target is not limited to 1.

-- - Don Klipstein ( snipped-for-privacy@misty.com)

Yes and float the 4 foot marble in space and fire the grain of sand at it and get ZERO mm/sec change.

It really is like a millionth of what you need. At least.

Well, we've moved from 50 feet to 'the top few feet'. I said 1/4".

I'll bet that I have been closer all along than all of your ever changing "I caught a fish this big..." crap.

If that little push was enough to miss this time around, it will surely be even farther 'pushed' at a later time.

Best bet is to push the entire monolithic mass all at one time whenever possible.

But if God wants to send one here, it is gonna go as far up our asses as He wants to PUSH it.

You didn't get it. If there is enough energy to shatter it, there was also enough to push it, so even though shattered, it would still have had a directional momentum added to the pieces as well.

You made no considerations for particle size, or make up. Yes, it does matter.

Most of the energy you describe gets bounced, and very little gets imparted into the mass fully, and the grain crunches and collapses as it impacts, giving up a lot of its energy there as well.

The ships were decommissioned at those times, but the use of silk in the powder bags was a long time earlier, just as I stated.

You guys keep talking about vaporization of material.

Ever occur to you that a LOT of material was simply displaced downward?

A footstomp type packing of the Earth, as it were.

Quiz question:

Fire dead-onto a 2.5 metric ton spaceborne marble a .1 milligram grain of sand at 1 km/sec with respect to the 2.5 metric ton marble. What is the change in the 2.5 metric ton marble's velocity?

Hint: The change is not zero.

It appears to me so far that nuking a 1 km asteroid with a few or several megatons will achieve a goodly couple orders of magnitude greater velocity change than firing a .1 mg grain of sand 1 km/sec at a 4 foot diameter marble.

Remember to stop the asteroid from rotating first, or the thrust will average out to about zero. If it's a comet, you'll have to wrap it in a net or something to hold it together.

How do you precisely attach 100 rocket engines to a floating pile of gravel, or a dirty snowball?

John

Rock at rest. Fire. Rock will remain at rest. Rock may laugh.

A one km spheroid is a LOT of iron or even space rocks.

Attach? The same gravity holding the rock pile together would accept all the sidereal force applied to it by a rocket or explosion the same way a monolithic mass would. It would all move together.

While the Castle Bravo explosion created a crater at least 200 feet deep and at least 1.2 miles in diameter with a very low altitude air burst? (at least IIRC)

What if a similar-yield nuclear explosive or similar/greater megatonnage in a multitude of nuclear explosives detonated after getting a little depth of dirt over it/them?