useless, but cool

Too dependent on "special skills". Anybody can run a spindizzy.

Mark L. Fergerson

It'll be on the Wayback Machine. ;)

Cheers

Phil Hobbs

Given that many red giants fluctuate, and none of them has a very long life--they're the stellar equivalent of the 90-year-old marrying a fashion model--it hardly seems worthwhile. What's a few million years anyway? ;)

Cheers

Phil Hobbs

Good point but can a city-sized drive be scaled up to push a planet around?

Have to root around in my dusty stacks -- haven't read "Cities" for a while.

I only buy newspapers at weekends or on holiday. It is very hard to light a fire using online media or digital paper.

dino's way.

to spread

It is one of those jobs that is sufficiently difficult that the fastest way to get to the desired result is to wait until there is appropriate technology. The same rules of the game apply to anything that requires more than about 3 or 4 years continuous computation. It is faster to go to the beach for 2 years and then start from scratch using hardware that is twice as fast. Moores law is still holding up so far - though you may have to work at load spreading to get the full benefit.

nature

universe.

Perhaps. But with present technology we are not in the game.

It is a good 1980's scifi thriller film. DVD quality is poor. Ridley Scott produced it. Opening sequence based on Teesside steel furnaces. Music by Vangelis. Original had an inappropriate sentimental ending because of Hollywood suits. Directors cut(s) are a bit more hardline. Based on "Do Androids Dream of Electric Sheep".

RTG.

It is doing very well indeed considering its design lifetime. Radio telescopes have become more sensitive and bigger too so we can still get a decent signal. I hope that is true when it reaches the heliopause.

from going

Sending people even at solar minimum to Mars would be like signing their death warrant. At best they would have to be tended by robotic nurses on arrival and at worst they would not survive the journey.

technology advances.

It takes a fair bit of energy to move the Earths orbit.

have been around,

size of a slice of bread,

you would have been locked

people will be able to fly,

then any painter that ever existed,

by voice,

would destroy whole cities at once...

OTOH we are running out of new physics. That is a dangerous thing to say though - shortly after the last time someone announced that physics would be solved within the decade someone observed the radioactivity and the photoelectric effect. I cannot rule that out but any technology that facilitated the energies needed for interstellar travel would be very dangerous. A speck of dust at relativistic speed does a lot of damage.

Not at all. I made the comment about chemical rocket technology which is completely irrelevant to travelling to the stars.

down, and are made in China

The dollar is far too easy to forge.

Regards, Martin Brown

The drag at orbital velocity would still be a problem and once the star surface came within the Roche limit of the Earth we would accrete matter from the solar atmosphere. Red giants shed a fair amount of gas in their old age. M57 is a canonical example.

They don't stay red giant for all that long but the core gets to live on as a white dwarf, neutron star or black hole according to the mass it has when the fuel runs out and it implodes under gravity.

I am reminded of a risque late 1970's lecture title by an expert on cataclysmic variable stars:

Can a degenerate white dwarf find lasting happiness in the arms of a red giant? The answer was no. It all ends in tears.

Regards, Martin Brown

Dinosuars weren't out-evolved - they just didn't put enough money into their asteroid-watch program, and were collateral damage when a decent- sized asteroid got around to hitting the earth. That particular global extinction does seem to be the only one that has been caused by an asteroid impact, while global warming seems to have been a factor in several of the others.

-- Bill Sloman, Nijmegen

Then what is the Amazon 'Kindle" good for? Sounds like it is perfect for the job!

Just driving a nail through the lithium battery should do the trick.

Jeroen Belleman

the

quite

solar

do

.eg.

increase

They did it in the book "Cities in Flight". The City Fathers concept in that book is interesting as well. Though Mayor Amalfi turned out to have gotten pretty old.

I do suspect that the asteroid(s) would become notable (navigation) hazard(s) as a byproduct.

Not unless they got the deflection trajectory wrong. There is an Earth watch program to find and catalogue the orbital elements of all near Earth asteroids to check for future potential collisions. An asteroid of just a few km across would really spoil your day of it hit the Earth.

There are a handful of asteroids known to be in complex bound orbits around the sun and the Earth. One such is #3755 eg.

The objective would be to drop them in so that they slow the Earth down in its orbit and the asteroid exits the solar system on para/hyperbolic orbit taking some of our momentum with it. You wouldn't want to leave them in a bound elliptical orbit - that would be asking for trouble.

We would have to be pretty desperate to try this sort of measure. Imagine what the press would make of it given their response to QQ47 doomsday asteroid panic.

Regards, Martin Brown

Mathematics is often more useful than suspicions. It would be easy to design a hyperbolic path that would steal most of the angular momentum of an asteroid. What happens to an object 90e6 miles from the sun that has nearly no angular momentum?

NASA has long used ultra-precise hyperbolic flyby trajectories to boost spacecraft into deep-space paths, farther out than we could easily accomplish with direct rocket thrust. Orbital momentum transfer is already a useful tool.

John

Wow, that's cool.

Or drop them into the sun.

John

"Suggestions are being taken for a good name for this asteroid. "

How about "Obamaturd" ?:-) ...Jim Thompson

-- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at

Obama says, "I AM NOT a cry baby, Fox REALLY IS out to get me!"

There is a *much* cooler one with an orbit that is like a long sausage bent around the Earth's orbit. And this newer one I found while looking for it.

Paradoxically it takes a lot more energy to drop something into the sun starting from our orbital velocity than it does to send it out to infinity. Probes bound for Mercury need very big rockets!

Regards, Martin Brown

But our goal is to steal all the angular momentum that we can. Ideally we'd leave the asteroid nearly motionless after we suck it dry, and let it drop directly into the sun. Splat!

John

That would be Cruithne. It's orbit looks weird indeed, from an earth-centered perspective.

However, the asteroid simply orbits the sun in an elliptical orbit that happens to have a period very close to one year. It looks much simpler that way.

Apparently it *does* exchange momentum with the earth from time to time, so that over a period of several hundred years, it is locked to the earth's orbit around the sun. The lock-in transient hasn't died out yet, it would seem.

Jeroen Belleman

Using the Al Gore Rules of Physics ;-) ...Jim Thompson