Starship Asterisk*

I like this quote.

craterchains wrote:When it comes to doing the math, we have found that the more posters using distractions, detractors, slander, lies, and deceptions in the threads we post questioning something, the more likely that deeper research is warranted on that subject. Your attitude and methodology of posting says allot. Thank you.

Finally, one last question; If many write like many are trying to detract, distract, twist, deceive, lie, and slander the posters questioning aspects of given public information, how can we not question their motives for posting?

Norval

Norval

Crater - I presume you only come on here with a theory that you know yourself is total hogwash because you crave attention. Very odd.

When it comes to doing the math, we have found that the more posters using distractions, detractors, slander, lies, and deceptions in the threads we post questioning something, the more likely that deeper research is warranted on that subject. Your attitude and methodology of posting says allot. Thank you.

I like that quote as well, mostly due to its irony (and I realise you probably don't understand the meaning of that word, but look it up) coming from you.

I challenge you to provide one example of where I have posted lies, distractions, slander or deceptions. (I definitely am a big detractor of yours and any qseudoscientific drivel)
By the way it is not slander to tell the thruth even if it is uncomfortable for you, I may have insinuated you are mentally unbalanced but that is because your reasoning lacks any logical pattern that I can dicern. I think the majority of people would agree with that statement.

As for distractions, well this is just another one of yours, I'm going to keep asking this until you provide it or get lost. WHERE IS YOUR EVIDENCE?

astro posted the following;
Posted: Fri Aug 25, 2006 3:38 pm
I'm not sure what your actually driving at, but in general the objects that have caused the damage you describe are considerably smaller than objects that cause major craters, which are fortunately very rare after 5 Billion years of impacts.

Posted: Sun Aug 27, 2006 4:01 pm
I think you will find that most great discoveries of the last 200 years actually came from people who did have a great deal of formal education (for the time period in which they lived).

Posted: Mon Aug 28, 2006 8:25 am
{Then he narrows it to just a hundred years.}
1. The lightbulb was invented more than 100 years ago.
{He then gets corrected by others, and then says;}
I was thinking more along the lines of something truely novel, like the transistor or jet engine.

Do any of you think he has a clue as to how the transistor really came to be and who finally got it to work? I highly doubt that he would know also, that because of the working transistor we had to change a major accepted theory.

My deepest apologies for having thought the following was you, astro, instead this one belongs to "iamlucky13" and I quote concerning Meteor and Wolf Creek craters;
It was not remotely logical to think it was a man-made nuclear bomb because there is no evidence at all that any man possessed a nuclear bomb however many thousands of years ago. In fact, the biggest bombs we've ever built could not dig a crater that big.


Besides, the last two biggest craters made on this planet were by fifty mega-ton H bombs, one by the USA and one by Russia, and both leaving about a mile big crater. About the same size of Barringer / Meteor crater and Wolf Creek craters. Fancy that. Long before Shoemaker made his investigations, these bombs went off, and left the craters to prove it.

A we have far, far bigger "gadgets" today.

Norval

craterchains wrote: Do any of you think he has a clue as to how the transistor really came to be and who finally got it to work? I highly doubt that he would know also, that because of the working transistor we had to change a major accepted theory.

Please tell me you have some stark raving mad conspiracy theory about transistors actually being invented in some guy's shed.

The rest of us can just go on "believing" that three highly educated physicists working at Bell labs won the Nobel prize for inventing the transistor:

http://en.wikipedia.org/wiki/William_Shockley (formulated the field effect equations that govern how transistors work, created the first junction transistors)
http://en.wikipedia.org/wiki/John_Bardeen (along with Brattain designed the first point contact transistors)
http://en.wikipedia.org/wiki/Walter_Houser_Brattain

craterchains wrote: Posted: Mon Aug 28, 2006 8:25 am
{Then he narrows it to just a hundred years.}
1. The lightbulb was invented more than 100 years ago.
{He then gets corrected by others, and then says;}
l

What the hell are you on about? I read astro_uk making his claims about the lightbulb being invented more than 100 years ago here but nobody disagrees with him. There is a very good reason for this: HE IS 100% CORRECT!

Swan demonstrated his first electric lights in 1878 and by 1879 Edison had invented bulbs that could burn for up to 40 hours.

I'll save you busting out the abacus to do this calculation, the lightbulb was invented 127 years ago.

But that doesn't alter the fact that it is the single most important invention of the last 130 years and is directly responsible for the method that you are currently using to communicate your ideas to others and to obtain the information needed to back them up.

Light bulb ~~ Vaccuum Tube ~~ Transistor ~~ Integrated Circuit Chip ~~ Computers/Internet.

Nice posts almighty. Norval tends to try to distort when he has been caught out and this is just another example of that. My point was only that its almost impossible for people in such a highly complex business to make discoveries on their own without any prior training. Edison is a perfect case in point, his most famous "invention" was nothing of the sort, it was a case of patent fraud, and most of the rest were actually made by a team of physicists and engineers working for him.

Whats your problem with the first quote their Norval? its pretty uncontroversial that as time goes by you get less impacts because your running out of asteroids/comets.

The challenge remains Norval, present something where I lied, distorted etc.

Your factually incorrect about something else again their Norval, the Russians did indeed test a 50Mt nuclear weapon (it was actually capable of 100Mt, but they scaled it back because of fallout concerns) but the largest weapon ever tested by the USA is 15Mt.

So Norval we have dealt with another of your distactions. Lets all repeat again. WHERE IS YOUR EVIDENCE?

BMAONE23 wrote:But that doesn't alter the fact that it is the single most important invention of the last 130 years and is directly responsible for the method that you are currently using to communicate your ideas to others and to obtain the information needed to back them up.

Light bulb ~~ Vaccuum Tube ~~ Transistor ~~ Integrated Circuit Chip ~~ Computers/Internet.

I don't think anybody would disagree with you that the lightbulb is a very important invention, but in my last post I was addressing a specific falsification on the part of craterchains.

Never said a word about how important (or otherwise) the invention of the lightbulb was.

Anyway I really need to get some sleep now.

The USA did a 50meg at Bikini atol. Look it up.

Like I said, you should read alot more and type far less astro.

Norval

I have looked it up Norval, according to all the usual channels the largest nuclear weapon exploded by the US was codenamed Castle-Bravo and had a yield of 15Mt, check it out here

http://www.johnstonsarchive.net/nuclear ... tests.html

or here

http://nuclearweaponarchive.org/Usa/Tests/index.html

or here

http://www.brook.edu/fp/projects/nucwcost/50.htm

33. Largest U.S. explosion/date: 15 Megatons/March 1, 1954 ("Bravo")

or here

http://en.wikipedia.org/wiki/List_of_nuclear_tests

This last one is probably where you got your faulty information from, it lists the yield from the Castle series of 6 (48 Mt total) tests not the size of a single blast.

The largest single test by the US is 15 Mt and that was actually twice what was expected,


So Norval are you man enough to admit your were wrong? I will if you provide me with a link that disproves all the ones above.

Sloppy Norval, very sloppy. And here was me thinking you were an expert researcher

hmmmm what can I say? guess I am wrong according to YOUR web information.

It appears that the pages we had are now gone from the web.
, , , as Harry says, smile and live another day.

Norval

Hey crater, look at todays APOD. Can you redo the image with all the features of war highlighted and post it up please

Circle the image and yah have it.

Norval

Hey all...how fun, this discussion is still going. I wasn't checking over the weekend.

Craterchains, I did a quick google and found that indeed a 100 megaton blast would be sufficient to dig a crater of the scale of Barringer Crater. That is still very far short of more sizeable craters visible around the solar system. There is a phenomenally huge crater on one of Saturn's moons...Minas I think. Still, I'm not terribly concerned with size.

I also note that in another post you basically did endorse the aliens blowing stuff up theory ("Long before Shoemaker made his investigations, these bombs went off, and left the craters to prove it."). So now we can cover both points 1 and 2 that I mentioned: A problem with the current theory (no impactors) and an alternative theory (a mega war). I'm going to continue discussing my 1, 2, 3 because they're useful for me in organizing my thoughts.

You still have not provided any evidence directly in support of your altnernative theory (3). The lack of impactors is the problem you point out with the current theory (1), but that by itself does not imply aliens with nukes. Not to mention, no one in this discussion has found any sources indicating that a high energy impactor actually should survive. As far as bodies with low escape velocities having craters but no impactors, consider this: The very fact that there is a significant crater there implies that a high energy impact occurred. If the velocity of the impactor were too low, it would bounce off or just crash land. Also, staying away from math and sticking with a gut-feeling approach to science that you seem fond of, if there is enough energy to pulverize and displace hundreds or thousands of times the volume of the impactor out of the crater, why should the impactor not be pulverized or even vaporized, too?

Now as far as your alternate theory goes, I honestly can not offer any direct evidence that aliens did not do it. I also have no evidence that there is a largest prime or that Santa Claus and the Easter Bunny don't exist. However, neither have I seen any evidence that they do exist. You could spin UFO sightings as evidence, but there has been no decent evidence (I don't count abductee claims as decent) that UFO's are alien spaceships (the Air Force has found a remarkable number correspond with SR-71 flights), and no evidence of any kind that these UFO's carry gigantic nuclear weapons or like blowing stuff up. Additionally, there's not even evidence of targets. Were the targets really condensed enough that they were completely obliterated by single attacks? Even near ground zero in Hiroshima there was plenty of evidence of the city that was there. And why would an entire civillization at war place itself entirely within effective range of a single weapon? We can find trillobite fossils and dinosaur bones hundreds of millions of years old, but there is no evidence of a civillization advanced enough to warrant the use of a 100 MT or larger weapon 50,000 years ago at Barringer.

One more thing I would like to bring up is a problem with the theory of alien warfare that is equally as troubling in my mind as the lack of impactors seems to be in your mind. Barringer was formed 50,000 years ago. The Tunguska event was just 80-90 years ago. The Yucaton event believed to have wiped out the dinosaurs was 65 million years ago. The Vredefort Crater in South Africa is estimated at 2 billion years old. Has this war really been going on for 2 billion years or are you discrediting far more modern science than just studies of craters (like carbon-14 and strata dating methods)? For extraterrestrial examples, look around for craters inside craters, check out the old craters on Dione in today's APOD, or if you look really deep you may find mention of new craters visible on Mars that were not seen in observations from the 60's.

Like I discussed before, I'll try to do some calculations to determine whether a high speed impactor could be expected to survive. I'm pretty busy today, so I might not get to it, but I figure it should be an interesting exercise.

, , , got it all figured out don't yah.

Norval

P.S. I KNOW what happens to high velocity projectiles, they go splat into a bunch of peices or are vaporized upon impact. Get over it.

But, that leaves the slow movers still unaccounted for.

If a slow moving chunk of rock/iron comes in at an angle of about 15 degrees, weighing about 200 kilos after atmospheric burn-off leaves behind the nickel iron remnant and strikes the earth at about 1000kph, it would most likely survive the impact, producing a hefty crater from the kinetic energy, but in all likelihood would also bounce out of the impact site and come to rest within the ejecta field outside the crater.

To have an impactor remain inside the crater it would likely need to be small enough and travel slow enough that it isn't vaporized/shattered upon impact and strike at an angle that would prevent it from skipping out of the impact site but still be large enough to carry enough kinetic energy to force the necessary disruption of soil.

Any ideas about what critical mass size and necessary impact angle is to accomplish this?

I would wager that in most cases, the required threshold is so rarely met that it would be the exception rather than the rule that a large impactor (100 - 400 kilo) is ever found inside the impaact site.

Not a problem BMA, I would like to see a "few" just near the craters they made.

Norval

I have to admit...I actually am finding this discussion fun and interesting, although, different. I searched up some surviving crater-forming impactors here:

Barringer Crater - Article mentions iron fragments and condensed iron droplets in and around the crater (I figured isolated small pieces should survive, but most articles focused on the crater, not the fragments).
Observed meteor fall - Low density meteorite found in the ice on a frozen lake
Meteor close encounters - Not very relevant, but interesting nonetheless.
Campo de Cielo meteorites - "The main part of the crater-forming mass was found in each of these craters."
2002 Siberian Explosion - Academic disucssion of the event. Probably exploded in mid-air, so it would have left no major crater.
1947 Sikhote-Alin Meteorites - Meteor broke up during atmospheric entry. Fragments left a crater field. Largest piece recovered was ~1700 kg.

On a different vein, extra-terrestrial impacts:
Shoemaker-Levy 9 Comet which hit Jupiter. Was observed by Hubble.
Craterchains - Brief article on crater chains on wikipedia. References Shoemaker-Levy 9
Martian Meteorite - Found by the mars rover Opportunity. No crater, possibly due to erosion.

Also, I think it's fair to point out that finding impactors on other bodies is extremely difficult due to size, despite the plethora of visible craters. The most detailed images we have of significant portions of another body come from the Mars Global Surveyor. NASA was able to find the Opportunity rover because they knew where to look and it looks significantly different from the sandy, rock-strewn landscape.

craterchains wrote:hmmmm what can I say? guess I am wrong according to YOUR web information.

It appears that the pages we had are now gone from the web.
, , , as Harry says, smile and live another day.

Norval

"Oh no, all the evidence I could've used to defend against your rebuttal just happened to be 'removed from the web' just when you argued me into a corner! What a coincidence!"

Riiiiiiiiight.

Here's a thought! Why would 1000's of weapons of mass destruction be used on hundreds of bodies of space that have no evidence of ever having been habitat-ed? Whether craters are caused by impactors or not; they more than likely were indeed caused by natural means.
Orin

As far as disintegration of the impactors, I went ahead and did some fast math for kicks and giggles. This is extremely simplistic and ignores the dynamic effects of what actually happens inside a failing material (it would take a computer doing a finite element analysis to even approximate that well), as well as changes in material properties that occur as it heats up due to the pressures involved.

My basic approach is to assume that pressures exerted through the meteor material can be approximated by calculating the force required to accellerate (via digging into the ground) an incremental mass over a given distance. In reality, this is far to homogenous and the actual result would theoretically yield portions that would survive as intact fragments, portions that melt, portions that are broken into a fine powder, and portions that actually evaporate. My incremental mass is a 1" cube of material representing any arbitrary portion of a large impactor. Any other similar chunk bears weight of its own mass. We'll ignore mass not forming the face of impact (unnecessary, but it's a conservative assumption)

Specific assumptions: Material is iron-nickel alloy, 90 degree impact, impact at 20,000 mph, uniform acceleration.

Newton related force, mass, and acceleration in his laws of motion.

F = ma

In a mechanical material failure, the important factor is stress, which is a force divided by an applied area. This has units of pressure (psi). To get just stress, we divide both sides by area (A). Also, mass is density (rho) times volume (V). So from F=ma we derive:

P = (rho*V/A) * a

The equations of motion tell us (not shown) that acceleration is the change in velocity (v) squared divided by 2*distance (s). We then have:

P = (rho * V * v^2) / (2 * s * A)

The University of Arizona lists the density of iron meteorites at 8000 kg/m^3. That's 0.29 lb/in^3. 20,000 mph is equal to 352,000 in/sec. We'll assume the meteor stops in 10 feet (120 inches). Volume of the incremental chunk is 1 in^3. Plug the numbers in and we get:

150,000,000 psi.

Since ultimate failure stresses of iron-nickel alloys are not widely published, I'll compare AISI 1045 steel, an alloy widely used in construction for high strength per cost. Matweb lists its failure stress in tension at 90,000 psi. Sheer information is not available but would be similar in magnitude. The stress in this example is over 1500 times the failure stress.

To give a little more insight, I re-arranged the equation to calculate the impact velocity that would cause exactly the failure stresses under these assumptions.

v = ((2 * P *A * s) / (rho * V)) ^0.5 = 8630 in/sec

That's 490 miles per hour. At that speed we would actually probably expect a large impactor to break into big pieces due to uneven geometry. For comparison, the terminal velocity of most small objects is around 200-300 mph.

By the way, if anybody wants to have fun digging virtual holes in the ground with math, the University of Arizona has a cool impact effects calculator. It's a much better approximation of what happens than my simple numbers.

Great calculator. I'll have fun with it

, , , yep, its all about craters in this thread, but in reality it is about craters with in craters, and within craters.

Or did yah all forget and get side tracked, again?

Norval