Teach me about the big bang theory.

Lord Kenneth

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I am uneducated in this field.

Also, A question I have:

Creationists maintain that something had to createor cause matter/start creation/etc. Ignore the fact that their own beliefs are hypocrisy... but, is that false?
 
Warning: what follows are the rantings of an armchair scientist.

You could probably find most of what you need by doing searches on the internet, though you might have to learn to filter the crap.

Here is the short "history" of the big bang. Others on here will be more accurate than myself.

1 ) Einstein general theory - doesn't predict a stable sized universe. The laws of physics demand that it either be contracting or expanding. To combat this Einstein initially theorized a "dark force" which caused some repulsion and resulted in a constant sized universe.

2) An astronomer (Hubble?) did some measurements that showed that the universe was expanding. Einstein's dark force was scrapped.

3) Scientists began to try to trace the universe back in time. From the current state of the universe and scientific theory they tried to calculate the state of the early universe. Far enough back you find that the universe was incredibly small space. Before that it would have been a point. To be accurate, the laws of physics as we know them breakdown before you can trace it all the way to being a point.



My knowledge of the evolution of the universe.

First we have the big bang. What caused it? We don't know. What pred-dated it? Probably nothing. No space, no time, nothing.

Very shortly we find the universe to be a dense quark soup. It is to hot for quarks to exist as stable protons neutron etc. Last I heard, our physics models are unreliable prior to the quark soup.

As the universe expands and cools, quarks are able to form stable bonds and become neutrons and protons and other junk, and eventually these can come to togethor and form atoms. Somewhere in here the universe becomes more or less transparent. Photons can travel with out being absorbed immediately, and it is this state of the universe which we the cosmic background radiation from.

Cooling and expanding continue, allowing more things to organize more into what we see today. When stars first form they become the breeding ground for heavier elements through fusion. Really heavy elements may be the results of collisions of heavy stars and such. But it are these events that start to fill out the periodic table. Super nova and these other catastrophic events are what spread these heavy elements until you get the state of things around our time and place that enable earth like planets.

I don't know if I explained well, I'm not sure if I explained it accurately, but that might be a good starting point. Hopefully people will speak up if I am talking nonsense.
 
The Big Bang Theory involves the universe expanding. There is the hot big bang model and the inflationary model. In Stephen Hawking's book, "A Brief History of Time", it says on page 162, "In the hot big bang model the rate of expansion is always decreasing with time, but in the inflationary model the rate of expansion increases rapidly in the early stages." I was told by my younger brother that it was found out recently that the universe is expanding at an ever quickening pace. This would fit in more with the inflationary model than with the hot big bang model.
 
Dark Cobra said:
I am uneducated in this field.

Also, A question I have:

Creationists maintain that something had to createor cause matter/start creation/etc. Ignore the fact that their own beliefs are hypocrisy... but, is that false?
Awright, lemme' have a shot at it. :)

The universe, that is all the "stuff" we can see and touch, all the energy, all the "space" (that is, the actual dimensions themselves) and some other things (called "dark matter" and "dark energy" because we can't directly sense them) all originated from a single point, what is called a singularity. A single "dot" like the points we learned about in high school geometry, with EVERYTHING all scrunched up inside it.

No, we don't know where it came from, but some theories are that it may have been from a kind of extra-dimensional "hyperspace" that exists outside of our universe, like our universe is an expanding bubble inside some sort of cosmic glass of beer. That's my favorite way to look at it, we're all part of a bubble floating in beer, heading for the foam. I just hope it's a GOOD beer!

Anyway, as soon as that dot/point formed, the "universe" began to exist. Time started (no, it didn't exist "before" this, time is just another dimension, like the space ones, try not to think of some sort of time running in the background -- this isn't like a movie). OK, so we have the hot dot and then, according to the best theories, we entered an "inflationary" phase. This means that the dot swelled up VERY fast, faster than light speed (if light had existed then, but things were still to hot and dense for light). In an extremely small fraction of a second the universe went from this point to very, very, big. I don't know how big, but BIG, like light years in size (I think), but it took 10e-25 seconds to get there. That's a decimal with twenty-five zeros after it, then a one. A very small moment in time.

Then things slowed down and we get to the "regular" expansion which we are still in. The inflated ball grew larger and cooler (remember though, there is nothing "outside" this "ball," it really is the only thing around (except maybe the surrounding beer, but nothing IN the ball can get TO the beer, too bad for all of us). As far as the ball is concerned it could "sense" that it may be getting larger but it can't tell anything about the "outside" world.

After expanding this way for awhile, different "stuff" condenses out of the soup as it cools. At ~380,000 years of age atoms and light can form, and suddenly the entire ball is full of gamma radiation, light and heat. It is VERY hot (I don't know how hot, I don't have the book handy, but you get the idea).

It keeps expanding and cooling, and stars, galaxies, quasars and other things we know and see form from gravity. The original inflationary time set up the "structure" and distribution of the stuff that would form atoms to make this possible. As it continued to expand and cool the original gamma radiation got "stretched" from red shift and became the cosmic background radiation we now detect. In fact, the original ball has cooled generally to less than three degrees above absolute zero, with the exception of the hot spots in and near stars, planets, and the other members of the cosmic zoo. But overall the universe has become pretty cold.

That "dark matter" and "dark energy" are invisible to us but seem to be real. The dark matter is detected by its gravitational pull and seems to make up a lot of what holds galaxies together. Calculations show that most of them would've flew apart if this dark matter hadn't been there all along (and seems to still be there) to increase their gravitational pull. That, and all the visible regular matter, have also been slowing the outward motion of the matter in the universe, and was once thought to POSSIBLY be enough to cause it to eventually stop flying apart and drag it back in to an eventual "big crunch," the opposite of a big bang.

That won't happen, though, because of that "dark energy." This is a force that seems to cause everything to REPEL everything else, in direct opposition to gravity. It seems to be undetectable at relatively close distances (like between nearby galaxies), but becomes more significant as distances increase. It is only relatively recently (like the last few billion years) that a good deal of the universe has become far enough from some of the other parts that it has become significant.

The net result of that dark energy is that the expansion will continue, but also accelerate with time. We'll never have a big crunch, so we may end with a whimper, not a bang, after all.

Sorry this ran long, but you did ask about the origin of the universe! :D
 
Re: Re: Teach me about the big bang theory.

garys_2k said:

A single "dot" like the points we learned about in high school geometry, with EVERYTHING all scrunched up inside it.

No, we don't know where it came from, but some theories are that it may have been from a kind of extra-dimensional "hyperspace" that exists outside of our universe, like our universe is an expanding bubble inside some sort of cosmic glass of beer. That's my favorite way to look at it, we're all part of a bubble floating in beer, heading for the foam. I just hope it's a GOOD beer!

Thanks for the input about what happened before the Big Bang. About a year ago I had a huge argument with a person who claimed that the Big Bang was the beginning of time and existence. I argued that it was not the beginning of time because if there was a Big Bang, there was motion, and without time there is no motion. So in order for time to move there would have to be motion to measure it by. Time is motion and motion is time. So there had to be time or motion in order for the Big Bang to occur because the Big Bang requires previous motion to trigger it. From there I argued that there was no beginning to time. This person I was arguing with just really wasn't getting it.
 
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The Big Bang Theory involves the universe expanding.
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Yeah, it expanded out of nothing!

Tell that one again, plleeeeaaassseee gramps! Pleeeeaaaassseeee!

I like that story.
 
Which story did you prefer? The one with the big magical being in the sky?
 
Well the Earth is actually a flat disc the rests on the backs of four elephants standing on agiant tortoise. Now while the sex of the tortoise for earth is unknown the fact remains that it must be either male or female.

This has lead scientists to conjecture that other worlds must also be floating on the backs of other tortoises, either male or female. These tortoises swim through the ocean of space towards a final destination where they will all indulgen in an orgiastic mating that has been referred to as the BIG BANG!

---apologies to Terry Pratchett
 
The question is, of course, what happened to the fifth elephant...
 
rwald said:
Which story did you prefer? The one with the big magical being in the sky?


No, I prefer the big nothing that existed in space that suddenly exploded. Yes, the one where nothing existed and exploded.

That is so much better than saying a god did it.
 
At least we're only claiming one impossible thing...

Wait, if God created the universe, than what created God? Oh, God's allowed to be immortal. But the universe isn't? Is that the sound of shifting goalposts I hear?
 
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Wait, if God created the universe, than what created God?
----


Maybe the "Big Nothing That Existed Then Exploded".


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Is that the sound of shifting goalposts I hear?
----


No, that was the sound of me undoing a severe 'frontal wedgie' I created from sitting down too long.
 
Something that people aren't mentioning is that to really understand the theory you have to learn some advanced math.
It is not as simple as talking about nothing coming into somethingness. Very counter inuitive, but many things in science are. But the neat thing is that once you do understand, you are often able to do useful things and make accurate predictions.

---------------------------------------------------------
WR to the posts that have been made so far:
Note that when people talk about the universe starting from a "point" it is not true. Singularities aren't physically "real", the are what happen when our theory is not accurate enough to predict the outcome.

I believe Michio Kaku talks about the lack of need for "first cause" in Hyperspace. Something to do with gauge theory which I don't understand.
-----------------------------------------------------------------

Even non-cosmologists like you and me, can appreciate that the theory has many subtle predictions, some of which have been confirmed.

You can verify that things like the 3 deg background radiation were being predicted before they were discovered. Other predictions include the energies required detect certain kinds of particles in accelerators. Astronomical measurements of the galaxies, their speeds of recession and spatial distrubution also let us know if our theory about how the universe started is consistent with what we can observe.

The short story is that we don't know exactly how the universe started, but out picture keeps getting clearer as more experiments are done. I believe that the big bang theory (which of course, encompasses many different specific plausible/consitent histories) is largely accepted and there are have been no observed data that strongly suggest an alternate origin. Remember that the timescales involved during the initial bang are phenomenally fast (10 to the -ve 10's of exponents), and the farther we go back, the less confident we are that our model accurately predicts the true picture.

Remember just becuase most people don't understand something completely, doesn't mean it isn't true; some things take a long time to understand. It is important to remember that scientists have used the model of the big bang to make important (and difficult) predictions; which is why we have confidence in the model.

That's not to say that there is a lot we don't know about the universe (i.e. why the surface of the sun is so damn hot)...even though we have things we can't explain, none of them suggest that the universe started in a different way.

P.S.
Have you tried ordering that pizza yet DC?
 
Whodini:
No, I prefer the big nothing that existed in space that suddenly exploded. Yes, the one where nothing existed and exploded.

That is so much better than saying a god did it.
Indeed it is. Guth, the father of inflationary theory, explains:

The Universe is the ultimate free lunch

An excerpt:
This borrowing of energy from the gravitational field gives the inflationary paradigm an entirely different perspective from the classical Big Bang theory, in which all the particles in the Universe (or at least their precursors) were assumed to be in place from the start. Inflation provides a mechanism by which the entire Universe can develop from just a few ounces of primordial matter. Inflation is radically at odds with the old dictum of Democritus and Lucretius, "Nothing can be created from nothing" If inflation is right, everything can be created from nothing, or at least from very little. If inflation is right, the Universe can properly be called the ultimate free lunch.
 
garys_2k,
A little careless, I think:
but it took 10e-25 seconds to get there. That's a decimal with twenty-five zeros after it, then a one.
10^-1 = .1
10^-2 = .01
10^-3 = .001
.....
.....

And some calculators (the one with win98) would have
10e-25=10*10^-25=1*10^-24=1e-24
so decimal point, 23 zeros, 1
 
Well, when one considers that 2800 years ago, it was believed the earth was on a tortoises back. . .

and 2200 years ago it was believed it was carried by a cursed man named Atlas. . .

and 1200 years ago it was believed to have been created by the hand of God. . .

and today it is believed to have been created by the Big Bang. . .

I think it stands to reason that in 1000 years:

1. There will be a different, newer, 'better' theory out there.

and

2. They will mock, redicule and laugh at all of the 'stupid ancients' who believed in that Big Bang hoo doo.


Look, as time and 'True' science change every hour, I get mroe and more skeptical of EVERYTHING science tells us is true. What, we are supposed to just believe for all eternity when they tell us something new and profound that, indeed, "THIS time, we are SURE we're right!"?

Come on!


Argue all you want, the Greeks were SURE the Earth was carried on the back of a giant tortoise. No question. Absolutely as positive, if not MORE positive then we are today of the Big Bang.


Oh, and hi all. My first post.
 
Welcome to the forum Larspeart.

Okay, starting with a pedantic point, it wasn't the Greeks that believed that the universe was on the back of a turtle.

The difference between beliefs and science is that science, by testing its assumptions, gets successively closer to how the world works. Science offers provisional truth, always subject to revision or negation. However, with science, this is based on new evidence, not changing beliefs. I'm sure many on this board will respond much more elegantly on this point than I will, so I will let them.

My question for you is: you just typed your answer on a computer, which uses a lot of engineering developed by science, all of which any competent scientist would describe as true (not True). Do you think in 1000 years that science will be laughing at us, calling them not true at all? Remember, computers really do work.

There is a huge change in methadology in the last 300 years or so of your timeline. The scientific method allows us to accumulate knowledge, not just change our beliefs. In 1000 years the science of our computers, for example, will still be correct (for example, how n-p-n junction transisters work). New science will be based on this knowedge, and of course the computers of that time will work in a different manner, but that makes today's semiconductor technology obsolete, not wrong.


So I don't see why in 1000 years scientists will be laughing at today's scientists. Current models on the beginning of the universe are based on incomplete data, and it is certainly possible that as more data comes available that theories may change. For example, Newton was quite wrong about the behavior of objects at relativistic speeds, but no one laughs at him or mocks him, for his work was based on scientific principles, and it remains correct at the non-relativistic speeds in which he performed his experiments.

Roger
 
Larspeart:
Well, when one considers that 2800 years ago, it was believed the earth was on a tortoises back. . .

and 2200 years ago it was believed it was carried by a cursed man named Atlas. . .

and 1200 years ago it was believed to have been created by the hand of God. . .

and today it is believed to have been created by the Big Bang. . .

I think it stands to reason that in 1000 years:

1. There will be a different, newer, 'better' theory out there.

and

2. They will mock, redicule and laugh at all of the 'stupid ancients' who believed in that Big Bang hoo doo.
I certainly hope that there will be a better theory. It would be a sad state of affairs if there was suddenly nothing new to discover.

However, I doubt any educated person would laugh at the current theories. No one laughs at the achievements of the ancient Greeks. Au contraire.
Look, as time and 'True' science change every hour, I get mroe and more skeptical of EVERYTHING science tells us is true.
Skepticism is important. However, when a theory is backed by evidence, peer-reviewed, etc, etc, its safe to assume that it describes reality fairly well.
What, we are supposed to just believe for all eternity when they tell us something new and profound that, indeed, "THIS time, we are SURE we're right!"?

Come on!
No scientist has this opinion. Science is an iterative process. No one laughs at Newton's gravitational theory, despite the fact that Einstein came along with a theory which explained more than Newton's. Heck, you can still send a rocket into space and a probe to Jupiter using just Newton's theory.
Argue all you want, the Greeks were SURE the Earth was carried on the back of a giant tortoise. No question. Absolutely as positive, if not MORE positive then we are today of the Big Bang.
Really? Odd, given that the circumference of the Earth was measured by the Greeks.
Oh, and hi all. My first post.
Hi, and welcome aboard.
 
Okay, excellent point. Now for my counterpoint.

Einstien had a number of very good views and points, most of which were/are true to this day in our thinking. However, there have (in just 50-80 years) been numerous ones that were widely held to be true, and are just now proving to be untrue. Take the speed of light, and the fact that, as he puts it, nothing can go faster. Twas a huge blow to time-travel buffs, but everyone looked at his theories and said 'yup, by Jove, the chap is right'. WRONG. We now have witnessed both in nature and in labs, faster then light travel, at the atomic and the subatomic level.

So, in not 300, but rather 50 years, what was once held as hard fact, is now somewhere between mostly true and incorrect.

Want more? The age of the universe. First, it was 8000 or so years old. Then, it was 1 billion years old, then 12. then 14. Just recently, I read that now, we think it is 14.4-16 billion years old, and another university believes it is at least 20 billion. So, you're going to tell me that in 1,000 years, they will still think it is 14.4 billion years old? Yet, hundreds upon hundreds of very respected scientists and math guys point to gobs upon gobs of 'hard evidence.

Humans believe that they can figure out the really good questions in life if they devote enoguh thought and math to the problem. The fact is, our brains are prone to several things, one being fallability. The other is ego. We believe that humans can figure out anything due to our greatness, and neglect that we are more often wrong in life then right.

I'm sorry, but just because we invented a computer for me to type on doesn't mean i believe that in 10,000 of true society, we have everything figured out yet.
 
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Want more? The age of the universe. First, it was 8000 or so years old. Then, it was 1 billion years old, then 12. then 14. Just recently, I read that now, we think it is 14.4-16 billion years old, and another university believes it is at least 20 billion. So, you're going to tell me that in 1,000 years, they will still think it is 14.4 billion years old? Yet, hundreds upon hundreds of very respected scientists and math guys point to gobs upon gobs of 'hard evidence.
----


Good points.

My prediction is that people will keep extending that estimate, and keep extending it on and on and on...

Then the people in the future will look back and say 'those people who thought the age was infinite or that the universe always existed were so ahead of their time'
 
Larspeart:
Einstien had a number of very good views and points, most of which were/are true to this day in our thinking. However, there have (in just 50-80 years) been numerous ones that were widely held to be true, and are just now proving to be untrue. Take the speed of light, and the fact that, as he puts it, nothing can go faster. Twas a huge blow to time-travel buffs, but everyone looked at his theories and said 'yup, by Jove, the chap is right'. WRONG. We now have witnessed both in nature and in labs, faster then light travel, at the atomic and the subatomic level.
I have no idea what you are talking about. No experiment done has challenged Einstein's theories.
So, in not 300, but rather 50 years, what was once held as hard fact, is now somewhere between mostly true and incorrect.
You don't seem to understand the nature of science.
Want more? The age of the universe. First, it was 8000 or so years old. Then, it was 1 billion years old, then 12. then 14. Just recently, I read that now, we think it is 14.4-16 billion years old, and another university believes it is at least 20 billion. So, you're going to tell me that in 1,000 years, they will still think it is 14.4 billion years old? Yet, hundreds upon hundreds of very respected scientists and math guys point to gobs upon gobs of 'hard evidence.
As measurement techniques improve and theories refined, these numbers get closer and closer to the actual value. What is the problem?
Humans believe that they can figure out the really good questions in life if they devote enoguh thought and math to the problem. The fact is, our brains are prone to several things, one being fallability. The other is ego. We believe that humans can figure out anything due to our greatness, and neglect that we are more often wrong in life then right.
What are the "really good questions in life"? The fact that humans are fallible is well known and one of the reasons for the peer-review process of science.
I'm sorry, but just because we invented a computer for me to type on doesn't mean i believe that in 10,000 of true society, we have everything figured out yet.
I agree. We certainly haven't figured everything out yet. In some ways I find that irritating because I'd like to know everything before I die. On the other hand, I suspect it would make life boring.
 
GoodPropaganda said:
garys_2k,
A little careless, I think:

10^-1 = .1
10^-2 = .01
10^-3 = .001
.....
.....

And some calculators (the one with win98) would have
10e-25=10*10^-25=1*10^-24=1e-24
so decimal point, 23 zeros, 1
Yeah, I was sleepy and I figured it out too fast. But what's an order of magnitude or two when we're talking amongst friends, eh? :)

My misteak, mea culpa.
 
Quote
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Want more? The age of the universe. First, it was 8000 or so years old. Then, it was 1 billion years old, then 12.
then 14. Just recently, I read that now, we think it is 14.4-16 billion years old, and another university believes it is
at least 20 billion. So, you're going to tell me that in 1,000 years, they will still think it is 14.4 billion years old? Yet,
hundreds upon hundreds of very respected scientists and math guys point to gobs upon gobs of 'hard evidence.
----

The problem here isn't that people don't agree on the age of the universe. The problem is that the numbers that you need to use to calculate it, such as the Hubble constant (the expansion rate of the universe) are uncertain and vary depending on what technique is used to measure them. The recent results from the MAP satellite give the age of the univerese as 13.7 billion years (+ or - about 0.2 billion years). Have a look at the NASA website - http://map.gsfc.nasa.gov/m_mm.html
 
Larspeart said:
We now have witnessed both in nature and in labs, faster then light travel, at the atomic and the subatomic level.

You would seem to be privy to information unknown to the rest of the world. A recent experiment showed a pulse of light passing through a medium apparently at faster-than-light speeds, but the transmission was such that no information could be passed. No material particles were involved.


Want more? The age of the universe. First, it was 8000 or so years old. Then, it was 1 billion years old, then 12. then 14. Just recently, I read that now, we think it is 14.4-16 billion years old, and another university believes it is at least 20 billion. So, you're going to tell me that in 1,000 years, they will still think it is 14.4 billion years old? Yet, hundreds upon hundreds of very respected scientists and math guys point to gobs upon gobs of 'hard evidence.

Recent announcements based on observations from the Wilkinson Microwave Anisotropy Probe have narrowed the age of the universe to 13.7 billion years with a 1% margin of error (http://map.gsfc.nasa.gov/m_mm/mr_age.html). Prior estimates were based on less accurate data or outright guesses. It's reasonable to expect that future measurements will only decrease the margin of error.

did
 
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As measurement techniques improve and theories refined, these numbers get closer and closer to the actual value. What is the problem?
----


The problem is that you will find statements that claim that the numbers are THE numbers. A prime example of this is in some school textbooks.


http://map.gsfc.nasa.gov/ContentMedia/990053b.jpg

Yeah, infinite temperature... that makes sense.

:rolleyes:
 
Larspeart said:
Okay, excellent point. Now for my counterpoint.

[Snippage about a misunderstanding re. Einstein's special theory of relativity and susequent experiments.]

Want more? The age of the universe. First, it was 8000 or so years old. Then, it was 1 billion years old, then 12. then 14. Just recently, I read that now, we think it is 14.4-16 billion years old, and another university believes it is at least 20 billion. So, you're going to tell me that in 1,000 years, they will still think it is 14.4 billion years old? Yet, hundreds upon hundreds of very respected scientists and math guys point to gobs upon gobs of 'hard evidence.
We're getting better answers all the time. The present one is that the universe is 13.7 billion years old, after correcting for the effects of "dark energy" that causes increased speed with distance.

Some of the problems we'd seen earlier with nailing down a better value were related to imprecision of measurement: we didn't have the technology to measure things closely enough to get a good value. That seems to now have been fixed.

In fact, this "dark energy" was originally proposed and then rejected by Einstein, but it turns out his original idea on it may have been correct: something that REPELS objects, very weakly, but works over vast distances. When we were going on the assumption that there was no such thing we found other measurements that didn't add up. Putting it back in made everything (including stars that seemed older than the universe) consistent again.

I have no idea what they'll be thinking the age of the universe will be in another one thousand years, but I'd be willing to bet the farm that a lot of our existing scientific theories will still be accepted as firmly established at that time.

We STILL accept Galileo's work (within the limits of his measuring capability), as well as that of Copernicus and Hubble. These people did good work and we've found nothing to fault in it WITHIN THE LIMITS OF THE TECHNOLOGY THEY HAD TO WORK WITH.

We're on the verge of gaining new understandings of the universe all the time, and when the new accelerator at CERN goes online in a few years we'll learn even more. Perhaps we'll arrive at a Theory of Everything at that time, as we can finally experiment with black holes.
Humans believe that they can figure out the really good questions in life if they devote enoguh thought and math to the problem. The fact is, our brains are prone to several things, one being fallability. The other is ego. We believe that humans can figure out anything due to our greatness, and neglect that we are more often wrong in life then right.
Some people do, yes, but that's where the scientific method shines. We question, question, challenge and challenge. Ask for proof, try to disprove. THAT is science, to not accept poorly qualified information as true, ever.
I'm sorry, but just because we invented a computer for me to type on doesn't mean i believe that in 10,000 of true society, we have everything figured out yet.
But those scientists in 1,000 years won't doubt that your computer worked, that it was designed to function with electronics and nanotechnolgy and that the ideas we used to develop it didn't explain adequately (to us) its function consistent with reality. We don't laugh today that explorers 500+ years ago DIDN'T fall off the edge of the earth, that they went around. We don't consider it humorous that Eratosthenes measured the diameter of the earth fairly accurately by measuring shadows. I am certain they won't think what we're doing is wrong, either.
 
Larspeart said:
Okay, excellent point. Now for my counterpoint.

Einstien had a number of very good views and points, most of which were/are true to this day in our thinking. However, there have (in just 50-80 years) been numerous ones that were widely held to be true, and are just now proving to be untrue. Take the speed of light, and the fact that, as he puts it, nothing can go faster. Twas a huge blow to time-travel buffs, but everyone looked at his theories and said 'yup, by Jove, the chap is right'. WRONG. We now have witnessed both in nature and in labs, faster then light travel, at the atomic and the subatomic level.

So, in not 300, but rather 50 years, what was once held as hard fact, is now somewhere between mostly true and incorrect.

Your point is completely incorrect. Nothing has been shown or observed to move faster than the speed of light in a vacuum (c).

Particles can and do travel faster than the speed of light in glass, water, or some other medium. There is nothing in relativity that would prohibit that.

Edited to add:
To be completely correct, relativity doesn't prohibit things from going faster than the speed of light either. What is specifically prohibits is anything crossing the speed of light threshold. In other words, once slower than the speed of light always slower than. Conversely, if ever faster than the speed of light then forever faster than the speed of light.

It is still true that nothing has been observed to go faster than the speed of light (in a vacuum) and certainly nothing has been observed to cross it.
 
Re: Re: Re: Teach me about the big bang theory.

JAR said:


Thanks for the input about what happened before the Big Bang. About a year ago I had a huge argument with a person who claimed that the Big Bang was the beginning of time and existence. I argued that it was not the beginning of time because if there was a Big Bang, there was motion, and without time there is no motion. So in order for time to move there would have to be motion to measure it by. Time is motion and motion is time. So there had to be time or motion in order for the Big Bang to occur because the Big Bang requires previous motion to trigger it. From there I argued that there was no beginning to time. This person I was arguing with just really wasn't getting it.
Time is motion? So if nothing was moving there'd be no time?

Time is another dimension, just like up/down, left/right and front/back. Exactly like them. All of that started, for our universe, with the big bang. There was no "before" that, at least for anything we could interact with.
 
Oh please.

Those kind of diagrams are often a result of people who are trying to communicate what the latest understadning is about the universe. Like many articles about popular science, they are seldom prefaced with "Well are best guess right now is....".

Sure kids will often take such things as scripture, but as we grow older we realize that there is no such thing as infinite temprature; the theory simply fails to predict the temprature at 0s since the assumptions we are making are probably untrue.

Please differentitate between a fair mistake in science communication with the actual science being done.

Whodini said:
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As measurement techniques improve and theories refined, these numbers get closer and closer to the actual value. What is the problem?
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The problem is that you will find statements that claim that the numbers are THE numbers. A prime example of this is in some school textbooks.


http://map.gsfc.nasa.gov/ContentMedia/990053b.jpg

Yeah, infinite temperature... that makes sense.

:rolleyes:
 
Whodini said:
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As measurement techniques improve and theories refined, these numbers get closer and closer to the actual value. What is the problem?
----


The problem is that you will find statements that claim that the numbers are THE numbers. A prime example of this is in some school textbooks.
That is the problem? Doesn't seem very serious. Although, I agree that a good school science book should say "about 14 billion years", or similar.
http://map.gsfc.nasa.gov/ContentMedia/990053b.jpg

Yeah, infinite temperature... that makes sense.

:rolleyes:
I suspect that the actual temperature is unknown, only that it is many orders of magnitude above the previous one on the chart.

[Edited to add: BTW, didn't you learn in elementary school that pi = 22/7? And then later you learned this was an approximation?]
 
In this case infinite temperature does make sense, as the intial singularity also had infinite density and zero volume. This is what life is like in a singularity: very hot, very tight and really, really cramped.
 
Larspeart said:
I'm sorry, but just because we invented a computer for me to type on doesn't mean i believe that in 10,000 of true society, we have everything figured out yet.

Who's said we have?

There's plenty of room for argument about issues like the big bang. There's no room for argument about issues like whether the Earth is round or flat. The strength of science is that it recognizes that it can be wrong, and accepts new evidence that discounts old theories. Tone of 'voice' is hard to read in posts, but you seem to be criticizing science for changing theories, and for absolute certainty. The former is a strength (to me), and the latter just sounds like a strawman argument.

Might I suggest you watch Nova sometime, if you are in the States, or otherwise have access to it. Watch when they interview some astronomer. The conversation usually goes along the lines of:

"Our latest measurements suggest an age of the universe of between X and Y billion years. These measurements were done in manner Z, which haves inaccuracies A. Some interesting work is being done by Professor B which gives a value of 2Y or more. Most scientists suspect that he is not accounting for the w factor, and experiments are being designed to test this hypothesis. Early results indicate this is the case, but more works need to be done."

Which is rather different than a statement that we "have everything figured out".


The fact is, our brains are prone to several things, one being fallability. The other is ego. We believe that humans can figure out anything due to our greatness, and neglect that we are more often wrong in life then right.
On the contrary, the scientific method is based on the assumption that we are most often wrong, and works around that (imperfectly) by requiring ample evidence, peer review, double blind experiments, falsafiability, etc. Ego is also a positive force - if you suggest a theory that is new, every scientist in your field will try to prove you wrong. Sort of like what is going on right here. You think you have a better understanding of how science works than scientists do, and forum posters like me are responding with alternative ideas. Shouldn't that process generally lead to truth rather than changable beliefs?

roger
 
garys_2k said:
In this case infinite temperature does make sense, as the intial singularity also had infinite density and zero volume. This is what life is like in a singularity: very hot, very tight and really, really cramped.

No it doesn't.
As I have stated in my previous posts, it just tells us the assumptions of our model are flawed at that point and do not provide an accurate prediction.
 
BOOM ::splat::

The sound of another exploding debate on Life, the Universe, and Everything and little soppy bits hitting Dark Cobra.

Just to separate it out:

Science & BB theory is an explanation how.
God (or no God) is an explanation why.

It's Apples and Oranges. I think Creationists and "Strong Atheists" (as compareds to agnostics or "Weak Atheists") are opposite sides of the same coin: each is trying to get into the other kid's playground.
 
gmol said:


No it doesn't.
As I have stated in my previous posts, it just tells us the assumptions of our model are flawed at that point and do not provide an accurate prediction.
As a "singularity" is outside of our understanding, then so would be the conditions within it. It's not so much that our models are flawed but that no model exists that could contain all of the "stuff" we have into so small a space.

Is it really infinite? Maybe not, sure, in a mathematical sense. I can agree with that, but it's as close to that as physically possible even under those conditions (whatever "those" were).
 
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Sure kids will often take such things as scripture, but as we grow older we realize that there is no such thing as infinite temprature;
----


So you are saying that the people at NASA haven't grown up?

They are quite competent, I assume you.


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the assumptions we are making are probably untrue.
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And there ya go.
 
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Doesn't seem very serious.
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It is very serious if generations of kids and adults think the universe is 14 billion years old.


----
BTW, didn't you learn in elementary school that pi = 22/7? And then later you learned this was an approximation?]
----


No, I started off being taught that 22/7 was an approximation.
 
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In this case infinite temperature does make sense, as the intial singularity also had infinite density and zero volume. This is what life is like in a singularity: very hot, very tight and really, really cramped.
----


You know what life is like in a singularity??

Cmon now.

List 10 other things in real life where:

a) there is infinite temperature

b) infinite density

c) and zero volume


I'll wait patiently and make a cricket sound.
 
Whodini said:
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In this case infinite temperature does make sense, as the intial singularity also had infinite density and zero volume. This is what life is like in a singularity: very hot, very tight and really, really cramped.
----


You know what life is like in a singularity??
Yeah, it's awfully hot, thick and tight! See, with everything scrunched up like that it's just tough to get a cab, let alone take a walk in the park (which is really right nearby, you know).
Cmon now.

List 10 other things in real life where:

a) there is infinite temperature
The coffee I just tried to drink but burned my tongue, my OLD car's vinyl seat after it's been in the hot sun a while, the oil I overheated when I dropped the mondu I was cooking, all sorts of things.
b) infinite density
Well, we have some peoples' closed mindedness, some of the mud I've had to scrape off my boots, the snow I had to shovel last week...
c) and zero volume
AH HAH! A single point!
I'll wait patiently and make a cricket sound.
:)

But anyway, who said the original singularity could be anything like something in today's "real life?"
 

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