Airbrush

You are correct. I don't mean there is a trend towards self-awareness, just that it is a possible outcome of evolution, or seeminly the pinacle of the evolution of life on Earth, humans. Intelligent design may be a misnomer like "Big Bang", an imperfect way to label what happened on Earth.

The merger of two supermassive black holes seems to me like the most explosive event since the Big Bang. Those things don't like to be pushed around. Does it cause a huge explosion like a supernova or a GRB? Is it more energetic than a SBH devouring a star?

The term intelligent design has meaning to me metaphorically as the aggregate of all physical laws and the properties and forces of nature, how they interact, how chemistry works, and how life evolves to become self-aware. To me the word God means this also. To add "er" at the end of intelligent design seems excessive because it sounds anthropocentric and thus unnecessary. It seems to me that existance has a "program" but I don't know about a "programmer".

If the universe was flat then would the balloon analogy not apply? The balloon analogy only works for a curved finite universe?

Would the 2-D creatures living on the surface of the balloon be able to see beyond very close objects? Or would their field of vision curve all the way around the balloon?

I can never get used to the balloon analogy unless the thin skin of the balloon was so thick it was thicker than the observable universe. If space was very curved, would that mean that if you looked at an area of space on the very edge of our visual horzon, you would see the same constellations of quasars and ancient galaxies by looking 180 degrees the opposite direction?

Please leave this here. What a mind-twister. I need to read that a few times.

I intend to do exactly that. Thank you that is cool info. Those are the kind of numbers. OK I just calculated an iron rock (7.5) X 20km/sec^2 X 0.5 = 75,000m/sec^2. What does that mean? Is that jouls? How many jouls is a lot of jouls? Did they ever mention which composition of bolides is most common among the bigger ones? I think I heard that asteroid impacts are far more frequent than comet impacts, and comets usually have more speed, especially if they arrive coming the opposite direction of our orbit, but that would be extremely rare.

How does the air burst of a rock explode so energetically? I read somewhere that a meteroroid of up to 10m across will explode in the atmosphere with about the energy of Hiroshima. I just cannot imagine how a rock that small getting instantly vaporized generates that much energy. Does any nuclear reaction occur? BTW while reading about Tunguska on wikipedia it said the explosion was 10 to 15 megatons, then it said it was 1,000 times Hiroshima. Both cannot be true. Hiroshima was less than 0.2 megatons (13-18 kilotons) and 1,000 times 0.2 megatons is only 200 times Hiroshima. "Estimates of the energy of the blast range from 5 megatons to as high as 30 megatons of TNT, with 10–15 megatons the most likely...about 1,000 times as powerful as the bomb dropped on Hiroshima, Japan...." http://en.wikipedia.org/wiki/Tunguska_event

Martin, those are excellent points you make and I did read that Big Bang misconceptions before, more than once, but the term "Big Bang" is a sad misnomer. They should call it the "Great Expansion" which would be more descriptive. My mind is stubbornly clinging to the image of a Bang in empty space. Could tachyons, or something like them, have something to do with cosmic inflation?

Good info Ophiolite. Those are the kind of numbers I had been wanting to see. Do you think that angle contributes to which bolides will explode in the atmosphere and which ones will reach the ground? Most will not hit the earth broadside at a 90 degree angle, but at oblique angles and the extended amount of time burning in the upper atmosphere, and slowing down, would help some to explode miles high, the way we think Tunguska did. Hiroshima-sized impacts are thought to happen every year in the high atmosphere. People must have always thought they were just lightning and thunder. http://en.wikipedia.org/wiki/Impact_event "The late Eugene Shoemaker of the U.S. Geological Survey came up with an estimate of the rate of Earth impacts, and suggested that an event about the size of the nuclear weapon that destroyed Hiroshima occurs about once a year. Such events would seem to be spectacularly obvious, but they generally go unnoticed for a number of reasons: the majority of the Earth's surface is covered by water; a good portion of the land surface is uninhabited; and the explosions generally occur at relatively high altitude, resulting in a huge flash and thunderclap but no real damage."

Thanks for asking. If tackies were created at the Big Bang, and they were like neutrinos, then they would have flown "away" from the Bang, outracing everything else. If anybody got in front of them they would nearly instantly pass thru them. If there was no wall to bounce off? What if tackies were like neutrinos and penetrated any "wall" with ease? Maybe even supernovas create tackies, or even black holes, but we don't recognize their signature.

The probable reason we cannot detect tachyons is because they could only be created by the Big Bang and therefore are already long gone outside our visual horizon.

Everything depends on how big it is and how far away it gets blown to pieces. For some sized objects it might be better to blow it into pieces to increase the surface area that gets burned up in the atmosphere. Or it could even cause some big pieces to miss the Earth entirely. I think (correct me if I am wrong) that small enough pieces will not explode in the atmosphere but merely burn up. If doing so should create an ozone hole, I think that would be the lesser of evils.

A few variables are if it explodes miles above ground, or if it impacts deep water, or shallow water closer to land, or on dry land. Composition of soil that gets vaporized and blasted into the atmosphere could matter, but I don't know how, I'm not an expert. If the Tunguska object impacted deep water a thousand miles from land then the tsunamis may have been unnoticeable but there would be significant water vapor blasted into the atmosphere. If it impacted shallow water, it would kick up dust and water vapor and tsunamis could be devastating locally. If it hit dry land then more atmospheric effects. It would be nice to get expert input on what these possibilities could mean. The 10km dino-killer impacted shallow water. Do most asteroids explode miles above ground? It must depend on steepness of angle of impact, and steeper, more direct, angles are less probable I suppose. A poster had proposed 3 or 4 rockets with a net stretched between them to slow or stop the asteroid. Of course we would rather deflect it, but maybe that is a way to deflect a loose aggregate without breaking it up into pieces. I guess that the more massive the object, the more solid it is. To find out how solid an object really is may require a mission to the asteroid to study it long before it crosses our path.

I always thought the Richter scale steps were 10 x each. So from magnitude 5 to 9.2 = Tunguska X 10 X 10 X 10 X 10 X 1.2 (X 10,200). It would take an impactor 10,200 times the mass of the Tunguska object which was about 30 meters across (how do you calculate the size of this hypothetical object which would create tsunamis comparable to the 2004 Indonesian earthquack tsunamis?), and the blast was equivalent to 1,000 Hiroshimas. An object moving at 5 to 10 miles per second will displace many times its own size in water, but the waves radiate out from only a point and dissipate more rapidly than wide-range earthquake-generated and focused tsunamis. What sized impactor could generate that much damage on that same area if the impact occurred at the center of the Indonesian earthquake ground movement.

Interesting info Mr. Skeptic. Is there a way to calculate approx what size impactor will generate a tsunami comparable to the 12-26-04 Indonesian earthquake tsunami? What earthquakes have over meteor impacts in an ocean is that earthquakes cause movements spread over hundreds of miles. Most meteor impacts displace far less water.

We are only worried about real big ones. For big ones it takes far less energy to deflect it, ever so slightly early on, than to try to slow it down. Probably impossible to stop it.

You hear that folks? Relax, enjoy life, buy a beach house. We have hundreds of years to prepare for the big one.

Not every few decades. It is possible there have been smaller impacts a few hundred years ago that went unnoticed. Not all explode miles high. Some reach the ground, or more likely the ocean. I'm not an expert, and I would like to get expert opinion on what kind of tsunamis would be experienced along the Southern California coast caused by a meteor 30 feet across impacting the ocean at a speed of 10 miles per second, 1,000 miles off the coast of California. Anyone want to venture a guess?

I agree with most of what you are saying and Tunguska-sized events, or larger, are very rare, maybe once in a thousand years, as you say. But Wikipedia estimates Tunguska as an air explosion 3 to 6 miles high and comparable to a very large nuclear weapon 10-15 megatons, or about 1,000 Hiroshimas, and it was only a few tens of meters across (about 100 feet in diameter). Consider an object only 10% the mass of the Tunguska object, and those impact Earth more frequently. If it is able to penetrate the atmosphere and hit ANY ocean, it WILL cause devastating tsunamis which will destroy high populations along coastlines. Such an impact happening hundreds of years ago would go unnoticed, except locally. But now with high population densities along coastlines, the results will be very noticeable, as we saw with the Dec 26, 2004, Indonesian earthquake tsunamis, results was 200,000 plus dead. But you are mostly correct, and not much will be invested in defense until one does damage. It will be in the news. Thanks for setting my mind at ease. http://en.wikipedia.org/wiki/Tunguska_event

Mr. Alien, my question about detecting tachyons was for the poster who was hypothesizing about them. Sorry for the misunderstanding. I will be carefull to not try to cut anything with neutrinos. Dark matter does whatever matter does, move or hang around. The point I was trying to make was that tachyons are not the only thing we cannot pin down as we like to.

Maybe so, and Mr. Alien pointed out they are called "tachyons", but how do you propose we can detect them? What is that kind of particle that can travel through light years of solid lead, like a hot knife thru butter? Dark matter cannot be seen, and it doesn't even move.

They should start working on something soon. I love to hear about the Kepler mission, but let's face the fact that Kepler will not save our planet from destruction, nor will it save anyone from a Tunguska-sized impact. First things first. More and better methods for detecting such objects, and a short-range, "last resort" defense system that can deflect the smaller objects. I envision something like a "rocket with weight" to simply crash into an asteroid at high speed to deflect it. Over time we can add redundant safeguards and longer range systems which will take much more time for development and deployment. The United Nations needs to start talking about a global tax to finance these defense systems. It may be that a common cause can bring the nations of the world together in peace. Some argue that WWII helped pull the US out of the great depression. Maybe the jobs created by Planetary Defense projects can help pull the world out of this global recession. And there much more to do. What about global warming and the energy crisis? Anyone looking for a job? I'd rather work on planetary defense than continue this lousy job as bookkeeper for a restaurant for the rest of my life. As Skeptic's Dad would say "You can't make a baby in less than nine months no matter how many women you assign to the task." Hahaha! But you can assign a number of women to work on different babies, and each baby can contribute to the overall mission of "saving the world". Unless you can find an "Octomom" to help out.

A group of countries is the best way. Since everyone on Earth would benefit, there should be a way to pass the costs along to every country on Earth, according to an equitable scale or responsibility. The wealthy have the most to lose, so the US would carry a heavy share of the costs. Transparancy about it all the way so no country would feel threatened by weapons in space.