Why are the craters on the Moon all perfectly(ish) circular? AND, is the 'Big Bang' theory of the bi

JackronRM · May 11, 2008

<p><font size="2">Just niggles really, but, is the Moon's gravity strong enought to attract meteors, perpendicularly, to its surfrace?  Why isn't there evidence of some meteors coming in at angle, hitting the surface with a glancing (scooping) blow?</font></p><p><font size="2">Also, Why doesn't the Earth protect the surface of the Moon, that is always facing us, from a lot of meteor hits?  Is this evidence that it wasn't always in a fixed (facing us) orbit? </font></p><p><font size="2">Given the 'evidence' that stars and galaxys are still 'being born' and 'dying', billions of years apart, how can we say that the 'Big Bang' theory of the birth of the Universe has any credibility?</font></p><p> </p> <div class="Discussion_UserSignature"> JackronRM </div>

Saiph · May 11, 2008

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Just niggles really, but, is the Moon's gravity strong enought to attract meteors, perpendicularly, to its surfrace?  Why isn't there evidence of some meteors coming in at angle, hitting the surface with a glancing (scooping) blow?Also, Why doesn't the Earth protect the surface of the Moon, that is always facing us, from a lot of meteor hits?  Is this evidence that it wasn't always in a fixed (facing us) orbit? Given the 'evidence' that stars and galaxys are still 'being born' and 'dying', billions of years apart, how can we say that the 'Big Bang' theory of the birth of the Universe has any credibility?  <br /> Posted by JackronRM</DIV></p><p> </p><p>Welcome to SDC!  Those are some very good questions btw.</p><p>a) The moon's craters are mostly circular because, well, all craters are basically circular.  Even angled strikes produce circular craters, and it's only the extremely glancing blows that'll produce the "scooping" blow as you call it.  IIRC it's becaues of the massive amount of energy liberated at the impact is basically an explosion at that point.  So it really rounds out any "obliqueness" to the crater.</p><p>b) I'm sure the earth does shield the moon a bit.  You should take a look at the far side of the moon.  Lots of craters!  Some of that is because the far side has fewer large Maria (the big flat dark spots) where we think giant impacts actually cracked the crust and allowed the liquid mantle to flow out and smooth things over.</p><p>c)  Big bang:  Well, there's lots of evidence for it.  One of the prime indicators is metal content in stars.  In regions with lots of star development, metal content is up (because stars form metals in their core due to fusion, then spread it out as they die).  The further away we look, the less metal in general we see.  BB theory says thats because these galaxies have had less time to grow, and die, and so fewer stellar generations have passed.  Fewer generations means less enrichment of the surroundings.</p><p>Gotta go, I'm sure other posters will provide more information

 </p> <div class="Discussion_UserSignature"> <p align="center"><font color="#c0c0c0"><br /></font></p><p align="center"><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">----</font></em></font><font color="#666699">SaiphMOD@gmail.com </font><font color="#999999"><em><font size="1">-------------------</font></em></font></p><p><font color="#999999"><em><font size="1">"This is my Timey Wimey Detector. Goes "bing" when there's stuff. It also fries eggs at 30 paces, wether you want it to or not actually. I've learned to stay away from hens: It's not pretty when they blow" -- </font></em></font><font size="1" color="#999999">The Tenth Doctor, "Blink"</font></p> </div>

DrRocket · May 11, 2008

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>... Given the 'evidence' that stars and galaxys are still 'being born' and 'dying', billions of years apart, how can we say that the 'Big Bang' theory of the birth of the Universe has any credibility?  <br />Posted by JackronRM</DIV></p><p>You must first understand that the Big Bang theory is not complete and that there are still open questions.  So don't expect it to be able to answer all of your questions.  With that said there is quite a bit of evidence supporting the general ideas of the Big Bang theory.</p><p>First and foremost is Einstein's general theory of relativity.  General relativity is the best theory gravity that we currently have available and it has been subjected to many tests that confirm the remarkable predictive capability of the theory, under most circumstances (more about circumstances later).  If one applies general relativity and runs the theory backwards in time, one finds a prediction that the universe (space-time in the language of relativity) was in an extremely compact situation in the "beginning".  The theory, in running time backwards actually shows the universe originating in a single point, a singularity.  Now, that may or may not be correct.  What it is taken to mean at the present time is that the theory breaks down in an analysis of the very earliest times in the universe (roughly from time 0 until 10^-33 seconds).</p><p>Some people have a lot of trouble with the singularity notion and tend to reject the theory as a whole because of it.  That is a mistake.  It is pretty clear that general relativity has enough validity to conclude that universe as we see it is the result of an expansion from an extremely compact beginning.  There is good experimental evidence.  The key piece of evidence is the measurement of the cosmic background microwave radiation, which is extremely to close to what general relativity predicts.</p><p>On the other hand for the earliest times, it is also clear that quantum mechanical phenomena are important.  General relativity and quantum mechanics are not mutually consistent.  Both are extremely accurate in predicting observed physical phenomena within their range of known validity.  General relativity applies to phenomena in which gravity is important, most often at very large distance scales.  Quantum mechanics is extremely accurate in predicting the behavior of particles at the scale of the atom or nucleus.  In the earlies times  both of those considerations are important.  We currently do not have a physical theory that can handle that situation.  That is why there is so much interest in developing a unification quantum mechanics with general relativity, a theory of quantum gravity.  It is also believed that such a unified theory will overcome some technical difficulties in the existing theories and result in a much cleaner picture.</p><p>The general theories of the universe, which includes the Big Bang addresses the questions of stellar formation, and of the death of stars as well.  I predicts that stars and galaxies will continue to form go through a life cycles that depends on the mechanics and materials of formation and experience different kinds of "death" some of which expel elements made in their "fusion factory" that go on to become parts of new stars or planets.  Star formation, rather than contradicting the theory, is really a part of it.</p><p>If you would like to read more about this from a physicist who made significant contributions I recommend either of two books (better yet, both).  One is Stephen Hawking's <em>A Brief History of Time.  </em>The other is by Steven Weinberg, "T<em>he First Three Minutes."  </em>Both of these guys are serious scientists.  Hawking holds the Lucasian Chair in mathematics at Cambridge and Weinberg has contributed to both cosmology and high-energy physics, receiving the Nobel Prize for his work in unifying the electromagnetic and weak force theories.  </p><p><br /><br /> </p> <div class="Discussion_UserSignature"> </div>

crazyeddie · May 12, 2008

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Just niggles really, but, is the Moon's gravity strong enought to attract meteors, perpendicularly, to its surfrace?  Why isn't there evidence of some meteors coming in at angle, hitting the surface with a glancing (scooping) blow?<br /> Posted by JackronRM</DIV></p><p>Actually, there is:</p><span style="font-family:Times" class="Apple-style-span"><font face="Times New Roman"><span style="font-style:italic" class="Apple-style-span"><span style="font-size:x-small" class="Apple-style-span">Careful </span></span></font><font face="Verdana"><span style="font-style:italic" class="Apple-style-span"><span style="font-size:x-small" class="Apple-style-span">–</span></span></font><font face="Times New Roman"><span style="font-style:italic" class="Apple-style-span"><span style="font-size:x-small" class="Apple-style-span"> while most craters are circular or close to it, a few aren't. There are oblong craters, stretched-looking distorted craters, scalloped craters, even square craters. The reasons for non-circular craters include the degradation or modification of the crater with age, the material strength of the target compared to the energy of the impact, and, yes, the angle of impact.<br /><br />Earth is a hugely active planet, with erosion by wind and water, volcanoes, and tectonic movement working to modify, subduct, bury, and destroy craters relatively rapidly by geological standards </span></span></font><font face="Verdana"><span style="font-style:italic" class="Apple-style-span"><span style="font-size:x-small" class="Apple-style-span">–</span></span></font><font face="Times New Roman"><span style="font-style:italic" class="Apple-style-span"><span style="font-size:x-small" class="Apple-style-span"> which is to say, over tens to hundreds of millions of years. The process is different on worlds with no atmosphere. On the moon, for example, volcanism has had a role in erasing and degrading craters. The mare on the moon are enormous impact basins flooded by basaltic lava, erasing all traces of previous craters. On older surfaces already saturated with craters, later impacts modify or erase earlier ones. Micrometeorites "soften" the sharp features of craters. Tectonism on airless worlds is uncommon, but on the icy satellites of Jupiter, viscous relaxation of craters and tidal forces have modified and erased craters.<br /><br />Your intuition that most impacts aren't perpendicular is spot on </span></span></font><font face="Verdana"><span style="font-style:italic" class="Apple-style-span"><span style="font-size:x-small" class="Apple-style-span">– </span></span></font><font face="Times New Roman"><span style="font-style:italic" class="Apple-style-span"><span style="font-size:x-small" class="Apple-style-span">in fact, perpendicular impacts are rare. In a large sampling of potential impactors, which can come from anywhere in the sky, the average impact angle is around 45 degrees. The spread of impact angles isn't entirely random due to gravity well effects and the fact that most bodies in the solar system orbit the sun and each other within a plane called the ecliptic, but it's close enough for this discussion.<br /><br /></span></span></font></span><p><span style="font-family:TimesNewRoman" class="Apple-style-span"><span style="font-style:italic" class="Apple-style-span"><span style="font-size:x-small" class="Apple-style-span">Impact angle has an influence on the shape of a crater, but the effect is small except when the angle is shallow, typically less than 20 degrees. When the impact angle is less than 10 degrees, crater distortion is quite pronounced. Because of the minimal variation in crater shape above 20 degrees, we have to look to other features to deduce more about the impact. Specifically, if the crater is large enough to be "complex" (rather than a simple bowl shape) we can look at interior structures such as the central peak or peak-ring in craters that have them and, outside the crater itself, at the ejecta (the debris that gets thrown out of an impact crater).</span></span></span><span style="font-style:italic" class="Apple-style-span"><span style="font-size:x-small" class="Apple-style-span"> </span></span></p><p><span style="font-family:TimesNewRoman" class="Apple-style-span"><span style="font-style:italic" class="Apple-style-span"><span style="font-size:x-small" class="Apple-style-span">For small, "simple" craters (under 4 km diameter on Earth, under 15 km on the moon, for example), the basic bowl-and-rim shape is characteristically circular except when the impact angle is less than 20 degrees, in which case you start seeing some aberration in the up-field (the direction the impactor was coming from) and down-field parts of the rim. When the impact angle is lower still, the entire crater becomes elongated. At near-grazing angles you can even have multiple craters. A very low angle impact crater can look like a butterfly, where ejecta sprays out almost perpendicularly to the impact direction, as in this example from the Hesperia Planum region of Mars:</span></span></span></p><p>http://www.esa.int/esaMI/Mars_Express/SEMZLM8A9HE_0.html</p><span style="font-family:TimesNewRoman" class="Apple-style-span"><span style="font-size:x-small" class="Apple-style-span"><span style="font-style:italic" class="Apple-style-span">Craters from shallow impacts can even look like a skipped stone on a pond (this may form due to the first impact fracturing the incoming body into multiple pieces, which each form their own crater down range). Craters Messier and Messier A on the moon, seen here:<br /></span></span></span><p><br /> <img src="http://sitelife.space.com/ver1.0/Content/images/store/3/7/73f7cdc8-f411-4aad-87ea-9c9dd7c14489.Medium.gif" alt="" />       </p><br /> <img src="http://sitelife.space.com/ver1.0/Content/images/store/7/13/57f38e05-db5a-4fd4-8d91-96e80b563ed8.Medium.jpg" alt="" /> <div class="Discussion_UserSignature"> </div>

MeteorWayne · May 12, 2008

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Just niggles really, but, is the Moon's gravity strong enought to attract meteors, perpendicularly, to its surfrace?  Why isn't there evidence of some meteors coming in at angle, hitting the surface with a glancing (scooping) blow?Also, Why doesn't the Earth protect the surface of the Moon, that is always facing us, from a lot of meteor hits?  Is this evidence that it wasn't always in a fixed (facing us) orbit? Given the 'evidence' that stars and galaxys are still 'being born' and 'dying', billions of years apart, how can we say that the 'Big Bang' theory of the birth of the Universe has any credibility?  <br />Posted by JackronRM</DIV><br /><br />Hi, and Welcome to Space.com!!</p><p>Good question, I've been out of town for a few days, so am in the process of catching up.</p><p>You've gotten some good answers on the other issues, but I wanted to address a misconception in your first statement. You said the moon's gravity is strong enough to attract meteors perpendicularly.</p><p>That is not correct, even for earth and the sun.</p><p>The impact angle is a combination of the object's original trajectory and the gravitational pull of the impacted object, be it moon, earth, or sun.</p><p>Unless the closing speed of the impactor and impactee is zero before the object enters the earth, moon, or sun's, the impact will not be perpendicular. An object that catches up to the earth, any other planet, or the moon at zero speed comes in at 90 degrees. Since that is impossible (if the closing speed was zero, it would never enter the moon or earth's gravitional field), it is <em>always</em> not perpendicular.</p><p>Another poster stated that all craters are circular except at very oblique angles. That is correct, from the evidence we have gathered. The impact angle needs to be very low (<20 degrees? That's what I recall...I'll check and see if my recollection is correct).</p><p>So crater shape is not an indicator of impact angle, except in glancing blows (much like earth grazing meteors, which can cover the whole visible sky) If it's circular, all you can say is it was not a surface skimming trajectory.</p><p>MW</p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

derekmcd · May 12, 2008

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Why doesn't the Earth protect the surface of the Moon, that is always facing us, from a lot of meteor hits?  Is this evidence that it wasn't always in a fixed (facing us) orbit?  <br /> Posted by JackronRM</DIV></p><p>This is indeed correct.  The moon's rotation

rbit resonance was not always 1:1...  One rotation about it's axis in the same time it makes one orbit of the earth.  This happened due to tidal friction between the earth and moon.  They both affect each other through gravitational forces resulting bulges due to the gravitational gradient.  At some point in the past, the moon was rotating on its axis faster than it orbited the earth, but the gravitation pull of their respective bulges acted as a braking mechanism.  </p><p>As the earth is rotating, the bulge is always slight ahead of the moon... and when the moon was rotating, it's bulge was always slight behind.  This creates an unbalanced gravitational force between the 2 planet in which the bulges attempt to line up with each other.  The earth, being more massive, won the battle and has kept the moon's bulge always facing the earth.  </p><p>The moon hasn't quit, though.  The earth's bulge created by the moon's gravitational pull is still always a little ahead of the moon.  The moon is slowly, but surely, tugging back on that bulge slowing earth's rotation down.  Eventually, the earth's rotation

rbit resonance will also be 1:1 with the moon (the earth doesn't orbit the moon, per se, but rather they both orbit around a common center of mass referred to as a barycenter).  Someday, only one hemisphere of the earth will be able to see the moon. </p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

JonClarke · May 13, 2008

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Why doesn't the Earth protect the surface of the Moon, that is always facing us, from a lot of meteor hits?  Is this evidence that it wasn't always in a fixed (facing us) orbit? </DIV></p><p>Welcome to the forum!</p><p>Remember that the Earth is a very small object in the Moon's sky.  It is not better an "umbrella" than aa coin aat arms length would be as one against earthly rain.</p><p>cheers </p><p>Jon<br /></p> <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em> Arthur Clarke</p> </div>

MeteorWayne · May 13, 2008

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Welcome to the forum!Remember that the Earth is a very small object in the Moon's sky.  It is not better an "umbrella" than aa coin aat arms length would be as one against earthly rain.cheers Jon <br />Posted by jonclarke</DIV><br /><br />Yes, the Earth does absorb impactors from that direction. I don't know off the top of my head when the moon became tidally locked to terra. A very interesting question!</p><p> </p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

crazyeddie · May 13, 2008

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I don't know off the top of my head when the moon became tidally locked to terra. A very interesting question!  <br /> Posted by MeteorWayne</DIV></p><p>The question is academic, according to this author:</p><p>http://astro.isi.edu/notes/tidallock.html</p><p>....because long before the Earth and Moon become tidally locked, the sun will expand into a red giant and destroy the two bodies.  </p> <div class="Discussion_UserSignature"> </div>

derekmcd · May 13, 2008

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>The question is academic, according to this author:http://astro.isi.edu/notes/tidallock.html....because long before the Earth and Moon become tidally locked, the sun will expand into a red giant and destroy the two bodies.   <br /> Posted by crazyeddie</DIV></p><p>I think MW is referring to <em>just</em> the moon being tidally locked.  I think a less confusing terminology would be to say the moon is in a 1:1 rotational

rbital resonance, but that's a mouthful.  The moon is tidally llocked to the Earth, but Earth is not yet tidally locked to the Moon.</p><p>And it is still debatable as to whether the Earth will become backyard bbq fuel or simply be engulfed by the sun and assimilated.  If the Sun's expansion happens faster than the Earth's orbit recedes, Earth will be inside the sun's atmosphere plowing through particles causing the orbit to degrade and spiral towards the center.  Conversely, it's possible that Earth's recession might be enough to avoid this.  This doesn't mean life will survive, just that the Earth may end up one day being the closest planet to it's white dwarf host... but it would be rather barren and show no signs of previous life by future prospecters. </p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

derekmcd · May 13, 2008

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Welcome to the forum!Remember that the Earth is a very small object in the Moon's sky.  It is not better an "umbrella" than aa coin aat arms length would be as one against earthly rain.cheers Jon <br /> Posted by jonclarke</DIV></p><p> </p><p>The physical Earth may not make a good umbrella, but it's gravity well does. </p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

MeteorWayne · May 14, 2008

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I think MW is referring to just the moon being tidally locked.  I think a less confusing terminology would be to say the moon is in a 1:1 rotational

rbital resonance, but that's a mouthful.  The moon is tidally llocked to the Earth, but Earth is not yet tidally locked to the Moon.And it is still debatable as to whether the Earth will become backyard bbq fuel or simply be engulfed by the sun and assimilated.  If the Sun's expansion happens faster than the Earth's orbit recedes, Earth will be inside the sun's atmosphere plowing through particles causing the orbit to degrade and spiral towards the center.  Conversely, it's possible that Earth's recession might be enough to avoid this.  This doesn't mean life will survive, just that the Earth may end up one day being the closest planet to it's white dwarf host... but it would be rather barren and show no signs of previous life by future prospecters. <br />Posted by derekmcd</DIV></p><p>I read something within the last 2 weeks from the scientists who predicted that the mass loss would allow the earth to move far enough away.</p><p>They have updated their model with recent data about mass loss and have come around to the view that we will indeed be inside the sun. Toast-a-rama.</p><p>I'll see if I can remember where I read it.<br /></p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

JackronRM · May 14, 2008

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I read something within the last 2 weeks from the scientists who predicted that the mass loss would allow the earth to move far enough away.They have updated their model with recent data about mass loss and have come around to the view that we will indeed be inside the sun. Toast-a-rama.I'll see if I can remember where I read it. <br />Posted by MeteorWayne</DIV><br /><br />Cheers, y'all</p><p> I am now enlightened on this one, but I'll be back soon with more evidence of my ignorance.</p><p>ATB - Jack</p> <div class="Discussion_UserSignature"> JackronRM </div>

kin · May 21, 2008

<p>There is no reasonable justification to connect the Big Bang to the beginning of the universe. The fact that a Big Bang occurred is easily justifiable with the observations at hand. However, suggesting that this Big Bang created the Universe is an unfounded hypothetical assumption without any scientific evidence whatsoever and any scientist that would claim that the Universe was created by the Big Bang isn't worth a second look.</p><p>A supernova is an event that occurs within our universe. The Big Bang is also an event that can apparently occur within our universe. Lets call it.... omeganova. Just as we discovered countless galaxies in our proximity of the universe, we may one day discover that our universe is infinitely larger than we can presently imagine with other "omeganovas" occuring trillions of light years away. </p> <div class="Discussion_UserSignature"> </div>

derekmcd · May 21, 2008

<p><strong>"There is no reasonable justification to connect the Big Bang to the beginning of the universe. The fact that a Big Bang occurred is easily justifiable with the observations at hand.However, suggesting that this Big Bang created the Universe is an unfounded hypothetical assumption without any scientific evidence whatsoever and any scientist that would claim that the Universe was created by the Big Bang isn't worth a second look.A supernova is an event that occurs within our universe. The Big Bang is also an event that can apparently occur within our universe. Lets call it.... omeganova. Just as we discovered countless galaxies in our proximity of the universe, we may one day discover that our universe is infinitely larger than we can presently imagine with other "omeganovas" occuring trillions of light years away."</strong> </p><p>The Big Bang Theory isn't meant to describe the cause or the beginning or however you wish to define it, it only describes its evolution from T=10^-33 seconds.  What was going on before that, nobody has a clue.</p><p>How could we discover "omeganovas" trillions of light years away if they are causally disconnected from us?  </p><p>How do you come to the conclusion the the big bang is an event that can apparently occur within our universe? </p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

DrRocket · May 21, 2008

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>There is no reasonable justification to connect the Big Bang to the beginning of the universe. The fact that a Big Bang occurred is easily justifiable with the observations at hand. However, suggesting that this Big Bang created the Universe is an unfounded hypothetical assumption without any scientific evidence whatsoever and any scientist that would claim that the Universe was created by the Big Bang isn't worth a second look.A supernova is an event that occurs within our universe. The Big Bang is also an event that can apparently occur within our universe. Lets call it.... omeganova. Just as we discovered countless galaxies in our proximity of the universe, we may one day discover that our universe is infinitely larger than we can presently imagine with other "omeganovas" occuring trillions of light years away. <br />Posted by kin</DIV></p><p>In a nutshell, every single sentence in your post is factually incorrect.  You don't know what you are talking about.<br /></p> <div class="Discussion_UserSignature"> </div>

kin · May 21, 2008

<p>Please explain how one can make the assumption that "Big Bang" = "Beginning of the Universe"</p><p>You can't. </p><p><font size="1" color="#ff0000">"How could we discover "omeganovas" trillions of light years away if they are causally disconnected from us?" </font><br /><br />The key word here being "if" and being causally disconnected from us? ... I see no evidence at this point that would justify such an assumption.</p><p>Lets put this into a semantics argument: </p><p>many science books quote: "the universe was created 14 (or so) billion years ago in a Big Bang."</p><p>I call shenanigans. Probably a religious conspiracy to tie in a creation myth into science. The logical statement would read as follows:</p><p> "14 (or so) billion years ago our observable Universe was <em>affected</em> by a Big Bang"</p><p>If the history of astronomy has taught us anything its that you must allow room for the Universe to be bigger than you thought it was. </p> <div class="Discussion_UserSignature"> </div>

DrRocket · May 21, 2008

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Please explain how one can make the assumption that "Big Bang" = "Beginning of the Universe"You can't.

"How could we discover "omeganovas" trillions of light years away if they are causally disconnected from us?"

The key word here being "if" and being causally disconnected from us? ... I see no evidence at this point that would justify such an assumption.Lets put this into a semantics argument: many science books quote: "the universe was created 14 (or so) billion years ago in a Big Bang."I call shenanigans. Probably a religious conspiracy to tie in a creation myth into science. The logical statement would read as follows: "14 (or so) billion years ago our observable Universe was affected by a Big Bang"If the history of astronomy has taught us anything its that you must allow room for the Universe to be bigger than you thought it was.  <br />Posted by kin</DIV></p><p>Sorry, but you are all wet.  One can indeed explain just that, and as the logical consequence of a theory that has a great deal of experimental validation rather than as an assumption.</p><p>Einstein's theory of relativity, starting from conditions as they are presently observed and calculating backwards predicts that the universe, a 4-dimensional Lorentzian manifold known as space-time began in an extremely compact form, the theory would predict a point.  At that point, which is time=0 the universe began in what is called the Big Bang.  Now, it is likely that the theory is not accurate prior to about 10^-33 seconds after the predicted time 0, but in any case it clearly predicts the origin of the universe as we know it from a what can be practically considered to be a point.  Note that what came into existence is all of space and all of time, they are one thing.  It was not an "explosion in space and time" it was essentially an explosion OF space and time.  This is a little hard to grasp, and the mathematics of general relativity is somewhat difficult and abstract, but that is what we are told by the best theory that we currently have available.<br /></p> <div class="Discussion_UserSignature"> </div>

kin · May 21, 2008

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Sorry, but you are all wet.  One can indeed explain just that, and as the logical consequence of a theory that has a great deal of experimental validation rather than as an assumption.Einstein's theory of relativity, starting from conditions as they are presently observed and calculating backwards predicts that the universe, a 4-dimensional Lorentzian manifold known as space-time began in an extremely compact form, the theory would predict a point.  At that point, which is time=0 the universe began in what is called the Big Bang.  Now, it is likely that the theory is not accurate prior to about 10^-33 seconds after the predicted time 0, but in any case it clearly predicts the origin of the universe as we know it from a what can be practically considered to be a point.  Note that what came into existence is all of space and all of time, they are one thing.  It was not an "explosion in space and time" it was essentially an explosion OF space and time.  This is a little hard to grasp, and the mathematics of general relativity is somewhat difficult and abstract, but that is what we are told by the best theory that we currently have available. <br /> Posted by DrRocket</DIV></p><p>Since you decided to say I was all "wet" I'll say thats the biggest load of crap I've ever read. Linguistically incorrect in the extreme, and the type of garbage that only the Pope would try to spout off as creation myth dogma.</p><p><font color="#ff0000">the universe began in what is called the Big Bang</font></p><p>I could just as easily rewrite it as:</p><p><font color="#0000ff">the Big Bang began in what is called the Universe </font></p><p>Except I'd be right and you'd be wrong. </p> <div class="Discussion_UserSignature"> </div>

DrRocket · May 22, 2008

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Since you decided to say I was all "wet" I'll say thats the biggest load of crap I've ever read. Linguistically incorrect in the extreme, and the type of garbage that only the Pope would try to spout off as creation myth dogma.the universe began in what is called the Big BangI could just as easily rewrite it as:the Big Bang began in what is called the Universe Except I'd be right and you'd be wrong.  <br />Posted by kin</DIV></p><p>New user name ?<br /></p> <div class="Discussion_UserSignature"> </div>

derekmcd · May 22, 2008

<p><strong>"The key word here being "if" and being causally disconnected from us? ... I see no evidence at this point that would justify such an assumption."</strong></p><p> </p><p>Do you understand what causal disconnection is?</p><p> </p><p><font color="#ff0000"><strong>"t</strong><strong>he universe began in what is called the Big Bang</strong></font></p><p><strong></strong><strong>I could just as easily rewrite it as:</strong></p><p><strong><font color="#0000ff">the Big Bang began in what is called the Universe </font></strong></p><p><strong>Except I'd be right and you'd be wrong."</strong></p><p> </p><p>Actually, the first statement is wrong, too.  It should read "the universe began <strong><em>with</em></strong> what is called the Big Bang". </p><p> </p><p> </p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

kin · May 22, 2008

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>"The key word here being "if" and being causally disconnected from us? ... I see no evidence at this point that would justify such an assumption." Do you understand what causal disconnection is? "the universe began in what is called the Big BangI could just as easily rewrite it as:the Big Bang began in what is called the Universe Except I'd be right and you'd be wrong." Actually, the first statement is wrong, too.  It should read "the universe began with what is called the Big Bang".    <br /> Posted by derekmcd</DIV></p><p>We live in a universe held together by a fabric of interconnected parts, a quantum entanglement rooted as far back as the big bang and likely before it. The assumption that t=0 for the Big Bang is relative only to the study of the Big Bang and its aftermath. The study of the Universe as it is analyzed today is only a study of the Big Bang. However, we should not make the mistake of assuming that the universe began with the Big Bang 14 billion years ago. Time is an integrated component of any calculation, and borrowing from quantum mechanics, I could easily posit that the positioning of my fingers (preparing to be snapped) currently exist in two quantum states. A snapped and unsnapped state. At the moment I snap my fingers a new universe will spawn into existance and two timelines will be created by the snapping of my fingers upon which all events can be seen to relatively flow.</p><p>Besides, we all know that t=0 is marked by the birth of Jesus. *snap*</p> <div class="Discussion_UserSignature"> </div>

DrRocket · May 22, 2008

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>We live in a universe held together by a fabric of interconnected parts, a quantum entanglement rooted as far back as the big bang and likely before it. The assumption that t=0 for the Big Bang is relative only to the study of the Big Bang and its aftermath. The study of the Universe as it is analyzed today is only a study of the Big Bang. However, we should not make the mistake of assuming that the universe began with the Big Bang 14 billion years ago. Time is an integrated component of any calculation, and borrowing from quantum mechanics, I could easily posit that the positioning of my fingers (preparing to be snapped) currently exist in two quantum states. A snapped and unsnapped state. At the moment I snap my fingers a new universe will spawn into existance and two timelines will be created by the snapping of my fingers upon which all events can be seen to relatively flow.Besides, we all know that t=0 is marked by the birth of Jesus. *snap* <br />Posted by kin</DIV></p><p>Nicely woven words, but devoid of meaning.  <br /></p> <div class="Discussion_UserSignature"> </div>

kin · May 22, 2008

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Nicely woven words, but devoid of meaning.  <br /> Posted by DrRocket</DIV></p><p>Much like your own posts.</p> <div class="Discussion_UserSignature"> </div>

DrRocket · May 22, 2008

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Much like your own posts. <br />Posted by kin</DIV></p><p>Hardly<br /></p> <div class="Discussion_UserSignature"> </div>

Why are the craters on the Moon all perfectly(ish) circular? AND, is the 'Big Bang' theory of the bi

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