Big Bang Problem

The topic here is the Big Bang; which is sometimes described as an explosion, although that description is a bit misleading. Nevertheless, we can see this explosion, in a sense. You can see it on your TV. Sound weird? The answer has to do with the answer to the question about an exploding spaceship.When there was an explosion on board Apollo 13, we knew about it; but not immediately. It takes time for any signal to get from the spacecraft back to Earth.At the time of the explosion, Apollo 13 was already on the way to the moon, and this means there is a short time delay in signals from the craft back to Earth. I don't know the exact distance. However, when the damaged craft was rounding the back of the moon, the crew set a record which is yet to be beaten for the greatest distance anyone has been from Earth... 400,171 km measured from the Earth's surface.Light, and radio signals, take more than a second to travel that distance. Thus, if there had been another catastrophic explosion as the craft began the long return to Earth, we would have taken more than a second to find out about it.Several deep space probes have been a lot further from Earth than this. The greatest distance for a space craft to be from Earth while still sending radio messages that we could read is for Pioneer 10, I think. Signals were received from 11.6 billion kilometres, and it took more than eleven hours for the signal to reach Earth.The closest star to Earth is just over four light years away. That means that light from the star takes four years to reach us. What you see twinkling in the sky for this star is an image of the star from four years ago. Most of the stars you see in the sky are several thousand light years away. If one of those stars blows up tomorrow, we won't see the explosion for more than a thousand years.In 1987, we saw a star blow up in the Large Magellanic Cloud. The explosion was visible to the naked eye. But it actually blew up 167,000 years ago. That is how long it took for the light to reach us.We regularly see such catastrophic explosions in even more distant galaxies; at distances of several billion light years. However, this requires a very powerful telescope to capture the light from such a distance explosion.Finally, the Big Bang is an explosion of space itself; which is rather different from any other explosion you might think of. That explosion filled all of space, and the light from that explosion continues to fill all of space. To get really pedantic, we can only see light from some time after the initial singularity, since the universe was originally opaque to light, but once space thinned out enough for light to travel freely, light began a long journey and we can see it now. Curiously, due to the effects of the expansion, the light also stretches and cools over time; that light is now called the cosmic microwave background radiation; and was first identified about forty years ago.You can see it now, on your TV, in a rather curious way. Just turn to a frequency where there is no station transmitting and watch the static. Something like 1% of what you are watching is the light signals from the explosion of space itself, and that signal has been travelling about 13.4 billion years.This is not all just random assumptions. There are good reasons for the statements given. They are discoveries, and thoroughly tested. We will no doubt continue to learn many new and amazing things about the universe as we continue to look openly at the world. The only aspect of the above which is even remotely tentative is the precise age of 13.4 billion years for CMBR; but that figure is now pretty solid, and certainly in the right ballpark.Cheers -- Sylas[This message has been edited by Sylas, 04-20-2004]

Shrug. No, not really. Perhaps it did, or maybe not. There are speculative proposals fitting either case. Basically, however, we don't really know what went on prior to the big bang. This is not a problem with the big bang itself. It just means we don't know everything yet. I'm cool with that.The other matters were not on topic in this thread.Cheers -- Sylas

Space exploded; everywhere. We don't know why. The Big bang is not about something at a point in space, but an explosion of space itself. This is hard to understand, but it is pretty much a consequence of general relativity.Someone who has no knowledge of physics and no education in the discoveries of astronomy over the last century or so will find the big bang just about impossible to comprehend, let alone believe. For sure, it is far easier to just believe in your own intuitions.Cheers -- Sylas

Since this is an experiment, you could fix some of the other errors also.Replace "inteligent" with "intelligent".Replace "ect" with "etc". Better still, delete it altogether. It makes no sense in the context.Replace "Zebra's" with "Zebras".Replace "painted on their own stripes" with "painted their own stripes".Omit the incorrectly placed commas after "proof" and after "animals".Desdamona thought it was rude of me in the other thread to remark on the poor spelling, grammar and punctuation. I don't agree; although I realize that such comments are rarely appreciated. It is like trying to let someone in a public place know that their fly is undone and wide open.Bear in mind that we are writing for a well known international forum. Material here is indexed by Google. The potential audience is not only the member list; articles it will be found by people from all over the world using search engines to find information on the creationism/evolution debates. Meaning no offence, you should know that consistently error filled writing does have an impact on readers. It is very noticeable.Cheers — Sylas{Adminnemooseus says to himself, as he writes: I have enough problems with my own spelling, to get too (not to) critical of others. I also love commas, and also tend to use excessive quantities of them. Also, board policy is that admin/moderator editing for structure is OK, but editing for content is not done. Sylas adds, I thoroughly approve of that policy; but you were not editing, and spelling and punctuation is not content. I would not want you to apply these changes as edits; this was intended as a helpful suggestion by way of example for the original author.}[This message has been edited by Sylas, 04-21-2004]

The Big Bang has plenty of evidence; more then enough to make it pretty much the only game in town. Cosmology is a field of science in which there is much we don't know and many alternative speculative theories about early stages in the universe. But all scientific models need to account for the evidence, and the evidence we have means that all scientific models are now basically variations on the Big Bang model in one way or another.I outlined the major lines of evidence which bear upon the matter in Message 108You won't even be able to have a meaningful opinion on whether or not the Big Bang is supported by evidence until you learn enough physics to understand what we are talking about when we discuss that evidence. This is a hard fact of life about science. Anyone has the right to an opinion; but they don't have the right to be sensible. It has to be earned, and it takes time and effort to learn enough background to understand what you criticize.You are welcome, if you so choose, to disbelieve the Big Bang, because you find some other notions a bit easier. But blanket statements like "no evidence" are merely ignorance.Cheers -- Sylas

Congratulations... the second apostrophe is correct. Adminnemooseus, take note. Seriously; I'm sorry I offended you with these comments. I realized that this was almost inevitable, but the matter has been so obvious that had to speak up. I'll return to exclusively substantive comments from here on.Cheers -- SylasAdded in edit: "only game in town" is a well known metaphor that captures precisely the scientific status of the Big Bang. I have already said that there is a lot we don't know. I agree with your next post on apostrophes in possessive pronouns.
Added in edit: I acknowledge a coup. Desdamona made a good catch of the error in this post. Touche. [This message has been edited by Sylas, 04-21-2004]

For clarity, I have taken the liberty of adding in coloured italics the rest of the paragraph you were quoting, and using the conventional quotation tags.I do understand and know the Big Bang to the level we have discussed here. I put a lot of work into that understanding; it has been built up over several years by amateur reading in my own time. A good background in maths and physics in my undergraduate degree has helped a lot. You don't need tertiary level education to get a solid understanding of the basics, but it is definitely a help. It was hard, but fascinating and well worth the effort. I don't try to "convince" people of things unless I have a reasonably solid understanding myself.I think education in science is worthwhile for its own sake; and that someone who is not themselves educated in science is not equipped to educate others. Education is not something that only happens at schools or universities. If you let them, discussion forums like this are powerful tool for mutual education. We are here to discuss and debate. It is a good place to thrash out ideas in the heat of critical challenge; this means we back up our claims, and retract them if we can't or if we recognize the merits of a refutation from others.Of course none of this was evidence for the Big Bang. I have previously directed you to Message 108. That is a post I wrote recently that outlines five major lines of evidence for the Big Bang. The five lines of evidence described in that post are:

• Cosmic background microwave radiation.
• Cosmological red shift.
• Distributions of isotopes for light elements; such as Deuterium.
• The independently derived ages for stars and galaxies.
• The implications of general relativity.

Read the post for more details. None of these will be easy to understand if you have not heard of them before. To appreciate them in any depth, you'll need a level of comfort with physics. They are solid empirical evidence which has meant that the Big Bang now a confirmed discovery about our universe, accepted by all but a handful of working cosmologists, and the remaining handful of objectors is looking increasingly ridiculous.The last decade has seen a flood of new evidence from space based observatories. It has opened up the field of observational cosmology dramatically. In my view, people will one day look back on the turn of the twenty first century as the golden age of cosmology. It is a very exciting time to be living right now for anyone interested in astronomy.Cheers -- Sylas

I've placed a reponse in Message 22. I invite others who feel they must respond to off-topic stuff to consider using this Free for all thread. I think that should be ok; it is there for rants.[This message has been edited by Sylas, 04-22-2004]

This is a fair question, but off topic in the thread. I have posted my answer at Message 23.Best wishes -- Sylas

Off-topic; but the association with "falling stars" is at least a bit astronomical, so I'll answer.No. "Falling stars" are actually meteorites; small chunks of rock from within our own solar system that have collided with Earth. They appear bright because they burn up in the atmosphere.There have been speculations about life being carried to Earth on meteors; and for this being a cause of occasional epidemics of disease. Those speculations are without evidence, and impossible given what we know of disease and meteorites. The possibility of life being transferred from one planet to another is on the edge of credibility, and deserves serious consideration despite being highly unlikely; but this has nothing to do with "germs", which are bacteria from Earth.A star would be very much larger than the Earth. Our Sun is a star. The other stars you see in the sky are like the Sun, but anything from 15 million to 50 billion times further away; and that is just the ones which are close enough to be fairly bright. Stars are much much larger than the Earth.Meaning no offense... did you know about this difference between stars and falling stars? I'm sorry if I'm repeating the obvious; but at this stage I am honestly unsure what you know about stars and falling stars.Cheers -- SylasAdded in edit. In the above, exchange the terms "meteor" and "meteorite", in all cases. I know the difference, but I tend to mix up the terms. Thanks to Rocket for the correction.[This message has been edited by Sylas, 04-22-2004]

Under the circumstances, I consider this thread is fair enough for questions of astronomy, even if they have nothing to do with cosmology.Let me recommend to you Meteoroids, Meteors, and Meteorites. This page is from the "Enchanted Learning" people. It is intended for children; but don't be put off by that. I use it reasonably frequently myself when I am unsure on a subject. In fact, I used it today to look for names of various dinosaurs. Lam will know why. This page is intended for grades 3 to 5, but the information is excellent, and well presented, with further links to much more advanced discussions.The "smoke" that exists in space is a bit different to anything on Earth. From the same site, have a look at the Eagle Nebula
The tallest column of "smoke" there is about 30 million times higher than the distance from Earth to the Moon. It looks like smoke, but in fact it is very thin indeed; far thinner than our own atmosphere. You can't see such gas clouds with the naked eye. For access to more descriptions and better images, see also The November 1995 Hubble shots of M16.Cheers -- Sylas

Strictly speaking, the Big Bang does not explain stars and how they stay in place. The Big Bang explains the very very early stages of the universe, long before any stars. It explains the origins of material from which stars are made. Stars are a different subject. I suggest we leave the Big Bang alone, for the moment. It is way way too complicated. Think back to the post where I cited five lines of evidence for the Big Bang; there is just too much background before we can even begin to discuss that at any depth.To understand what keeps stars in place, you first of all need to grasp what that "place" actually is. It makes no sense to speak of a star "falling" to Earth, because they are so very far away that Earth's gravity has no effect.Do you know what keeps the Moon in place? It is gravity. The Moon is in orbit around the Earth. In the same way, the Earth is in orbit around the Sun, and this is what keeps the Sun apparently "in place" in the sky.The stars we see; including the Sun itself; are in orbit around a large central structure, called a galaxy. Our galaxy is the Milky Way. We can't see it entirely, because we are inside it. From Enchanted Learning on Spiral Galaxies, here is an image of what the Milky Way would like, and also a photo of another similar galaxy, Andromeda. There is an entry in the Enchanted Learning glossary for Big Bang, but no detailed discussion. It is not really possible to talk about it sensibly at this level.Cheers -- Sylas

No idea. I don't know the names of the arms, and would have to look it up. Here is your chance to educate me a bit; check it out for me and let us know what you find. Which arm are we on? Which is the arm we see spread across the sky that gave the Milky Way its name?Cheers -- Sylas[This message has been edited by Sylas, 04-22-2004]