BB Theory vs. Theory of Evolution - which is more thrustworthy?

[superwolf]

Personally I regard the ToE as a fact, but is the BBT just as much of a fact? Can we trust both theories 100%, or are there gaps that need to be filled first?

 

[humanino]

The big bang theory successfully explains empirical observations such as Hubble's law, and made very accurate predictions with regards to (for instance) the abundance of primordial elements or the cosmic microwave background fluctuation spectrum, which beautifully agree with the observations. There is no serious evidence to doubt the general ideas presented by the big bang theory, although some details of the specific implementation into models are not fully clear. The way I see it, this is the case with most scientific models : they will powerfully simply encode a wealth of observed trends in just a few ideas, but when you go to the tiny structures, you will also always find specific examples which we do not understand well enough yet.

For both theories, there are quite a few things to work on, but it does not imply that the principles are wrong, it is just an expected feature of such general models.

 

[superwolf]

There is no serious evidence to doubt the general ideas presented by the big bang theory, although some details of the specific implementation into models are not fully clear.

What is it exactly that is certain, and what is not? Is it for instance not worth doubting that the universe expands?

 

[humanino]

What is it exactly that is certain, and what is not?

Nothing is ever "certain", and the general question is extremely vast.

First, not questioning the theory part, there is a likelihood for its parameters to be within certain error bars given comparison with data. For instance (a very elementary example), there is a very high likelihood that the Sun will rise tomorrow (calendar date) between 5 am and 10 am (silly example), and there is a very small likelihood that it will rise between 7:00:01 am and 7:00:02 am (GMT), if you integrate this over all Earth. Those likelihood being what they are, there still is negligible doubts that the Earth will still orbit around the Sun tomorrow. So a theory, even if not proven false, at best only has a domain of validity with a range of possible values for its parameters.

Second, there is no such thing (or we do not know of such a thing) as "the absolute likelihood for a theory given data". That from a pure logical point of view forces one to give up on the possibility to have an objective measurement of validity of a theory given data, only because we have no clue as to what the set of all possible theories is, even less how we could "measure it". For instance, it still is possible that the world out there is just a set up designed to test the development of intelligence, and how long it will take us to figure it out. To make it short, there is a likelihood for an agreement between data and theory, but not for a theory itself given data.

The above two points are just fundamental statistics. The points below are more related to the applications of classical and quantum statistics.

Third, you have two sorts of intrinsic randomness beyond those two first points, even given the perfect theory and the data with its error bars. One is classical chaos the second is quantum indeterminism. Classical chaos let's us know that Nature can conspire to ruin our models any point in time. If only the positions of the 8 (or more) planets run into an unstable configuration point, it is possible that the Earth be ejected from the system, and although we know by simulation that this is reasonably unlikely, we also know that we could not predict it on very long scales. Classical chaos would go away if we could have data without error bars and perfect computational power (which in classical physics is not possible in practice, but still possible in theory). However, quantum indeterminism finally let's Nature do really crazy things, with even less likelihood, but way wilder in principle. We may be talking about negligible probabilities over time longer than the age of the Universe, and volumes larger than its volume, but remember, once it has happened it does not matter anymore that it was unlikely ! And it happens constantly at small action scales, like inside nuclei, or at very short distances for very light objects.

Is it for instance not worth doubting that the universe expands?

Most probably it is not worth, this being a personal opinion given with all the above commentaries ! There has been numerous attempts, and there are still some, to alternate theories to the big bang expansion, but none of them had the simplicity and the elegance necessary. The evidences for the big bang make it really difficult to build an alternative model.

Is it worth doubting that the Earth orbits around the Sun ? It was worth searching for alternate theories of gravitation before Einstein, and it can arguably bring questions as to "who orbits around whom ?", but that was not obtained by questioning the motion of the Earth itself. By the same token, it seems to me that were we to find a new theory significantly different from the big bang model and superseding it, it would not come to us by questioning the big bang itself, but maybe by questioning more fundamental question, such as "what is the correct theory of quantum gravity ?". Even maybe progress in this last question will come from somewhere else too actually !

 

[Jimmy Snyder]

Personally I regard the ToE as a fact, ...

Then shouldn't it be FoE?

 

[superwolf]

there still is negligible doubts that the Earth will still orbit around the Sun tomorrow.

Lol, I don't buy that.

 

[xxChrisxx]

Then shouldn't it be FoE?

RAGE

I hope you were being funny, as anyone who uses the phrase 'Fact of Evolution' with conviction should be taken to a hole in the ground and have a building dropped on them.

I really really hate how people mistake facts and theories.

/RAGE

 

[Bladibla]

RAGE

I hope you were being funny, as anyone who uses the phrase 'Fact of Evolution' with conviction should be taken to a hole in the ground and have a building dropped on them.

I really really hate how people mistake facts and theories.

/RAGE

Well, its only called a theory as it is the highest form of proof possible without use of mathematics, i.e. the definition of theory. Hence, it isn't too far off to say fact of evolution.

After all, at a cellular level, evolution has been *observed* directly. Its just that at the large scale of human beings and complex animals the timescale of evolution is much, much slow.

 

[xxChrisxx]

When people say Fact of Evolution they mean to imply that

THEORIES ARE BLIND SPECULATION!

Theories explain facts therefore it cheapens them to say 'fact of anything that is a scientific theory'.

In that case why is it not 'fact of gravity' 'Atomic Fact'.

 

[Bladibla]

When people say Fact of Evolution they mean to imply that

THEORIES ARE BLIND SPECULATION!

Theories explain facts therefore it cheapens them to say 'fact of anything that is a scientific theory'.

In that case why is it not 'fact of gravity' 'Atomic Fact'.

Oh I see what your trying to say. Thats fair enough then why you think fact and theory should be distinguished.

But all in all, just because evolution is called a 'theory' doesn't disprove that it *does* happen.

 

[russ_watters]

Personally I regard the ToE as a fact...

Slight correction: you can't regard a theory as a fact. Evolution is an observed fact. The theory of evolution is not.

This may help answer the question...

 

[russ_watters]

When people say Fact of Evolution they mean to imply that

THEORIES ARE BLIND SPECULATION!

Theories explain facts therefore it cheapens them to say 'fact of anything that is a scientific theory'.

No, people say "only a theory" when they are trying to cheapen it. No one is trying to cheapen it here, they are only accidentally mixing the very real issue of the fact of evolution (which is observed) vs the theory of evolution (which is the explanation of the fact).

This would be like confusing the fact of gravity with the theory of gravity.

 

[superwolf]

Evolution is a fact and a theory.

 

[superwolf]

Evolution is an observed fact.

Is the expansion of the universe an observed fact?

 

[xxChrisxx]

...fact of evolution (which is observed) vs the theory of evolution (which is the explanation of the fact).

Yes I know its both and that's not what bugs me. When used in the correct context its fine. Its when people use the phrase:

'Fact of Evolution' combined with a phrase like "i've never seen in textbooks..." "why isn't it called..."

Its either deliberately (in in some cases a lack of understnding) coming to the misleading statement that 'theory' is akin to 'crackpot idea'

I also really hate it when people mess up lend and borrow.

 

[kasse]

Does it make sense do believe in both evolution and creationism?

 

[superwolf]

I recently saw a chemist on the telly who didn't believe in evolution. I understand him to some degree, as the ToE didn't get along well with his personal faith personal experience. What I don't understand is that people can ignore evidence just because thwy don't want it to be like that.

 

[russ_watters]

Is the expansion of the universe an observed fact?

Yes, it is. But if you are meaning to imply that the expansion of the universe is the big bang, well...

The expansion of the universe implies a big bang but it is not the big bang. The big bang is a single event that happened a long time ago and cannot be directly observed. It is a prediction of a theory, not a fact.

 

[russ_watters]

Does it make sense do believe in both evolution and creationism?

That depends on what interpretation of "creationism" you use. What the word typically implies is wholly incompatible with evolution. You can, however, consider the creation story as an allegory (or something else), which would allow compatibility.

 

[superwolf]

So, in the same way as observed micro evolution suggests that humans have evolved from lower species, the expansion of the universe suggests that there was a big bang once?

That depends on what interpretation of "creationism" you use. What the word typically implies is wholly incompatible with evolution. You can, however, consider the creation story as an allegory (or something else), which would allow compatibility.

You can believe that God guided evolution.

 

[humanino]

The big bang is a single event that happened a long time ago and cannot be directly observed.

I think many cosmologists would object to that. The big bang theory describes everything that happens after a given initial state, the past of which is sick in the model. The sickness is correctly named "singularity". I mean to say, although this is merely a semantic issue, the science is in what is after, not what is initially.

 

[Evo]

You can believe that God guided evolution.

Be careful with terms like "God" and "creationism". Discussion of the beliefs of individual religions are not allowed here. So, let's not go there.

No more discussion of religion or the thread will be locked.

 

[WhoWee]

Personally I regard the ToE as a fact, but is the BBT just as much of a fact? Can we trust both theories 100%, or are there gaps that need to be filled first?

Isn't ToE really just an extension/component of BBT...the next logical step of development?

 

[russ_watters]

So, in the same way as observed micro evolution suggests that humans have evolved from lower species, the expansion of the universe suggests that there was a big bang once?

Yes.

 

[russ_watters]

I think many cosmologists would object to that. The big bang theory describes everything that happens after a given initial state, the past of which is sick in the model. The sickness is correctly named "singularity". I mean to say, although this is merely a semantic issue, the science is in what is after, not what is initially.

Once again:

Big bang = event
Big bang theory = theory that predicts the big bang happened and models/describes/predicts what happened after.

You have to differentiate between the two concepts.

 

[humanino]

Big bang = event

The term "event" is something very specific in general relativity. It refers to the intersection of two light rays. There is no reason that all light rays should converge in the past to the same spacetime point, or "event", unless the Universe is compact, which is not what ΛCDM suggests. I am sure you are aware of these, but I just want to make it clear. Please correct me if I am wrong.

Big bang theory = theory that predicts the big bang happened and models/describes/predicts what happened after.

Maybe we could simply disagree on that, but the initial singularity is sick in the model, considered to be outside the big bang theory, and usually not what cosmologist refer to when they use the term "big bang". There has been, and there still is, many attempts to remove this initial singularity. There are many hopes that a correct theory for quantum gravity will remove all singularities, including the initial one, which reflects the common belief that infinities do not actually happen in Nature, but pop up in the calculations at the border of our abilities. So I believe that cosmologists do not interpret the initial singularity as a physical prediction, but only as a mere artifact. The sufficient assumption for them is a uniform hot initial state.

So I do differentiate between the two concepts. We do agree on what "big bang theory" refers to. You call "big bang" an initial singularity, most probably unphysical and doomed to be forgotten. I call "big bang" the initial state from where the theory starts, which is almost a fact, and can only be (in our present understanding) posterior to the Planck time.

 

[troyerryan]

Neither are thrustworthy. BBT everything came from nothing or ToE Humans evolved from rocks through billions years of evolution. and people don't beileve in super powers

 

[slider142]

Neither are thrustworthy. BBT everything came from nothing or ToE Humans evolved from rocks through billions years of evolution. and people don't beileve in super powers

Aside from the continual use of the anomalous "thrustworthy" instead of "trustworthy", I believe you have set up a Straw Man. That is, unless you can reference a source that mentions specific rocks that humans are supposed to have evolved from in this theory of evolution.
As for the BBT, although I do not believe I have seen that statement anywhere in the theory either, it is not really a point of argument to disagree with an established theory by the fact that one doesn't like its statements or personally finds them silly. This holds for evolution as well.
Consider quantum field theory; quantum electrodynamics is one of the most accurate theories available to date in its domain of application, but it is not usually intuitive. The proper test of a theory is empirical evidence and falsifiability.

 

[wildman]

Does it make sense do believe in both evolution and creationism?

Yes. See:

https://www.amazon.com/dp/1416542744/?tag=pfamazon01-20

 

[Moridin]

Yes. See:

https://www.amazon.com/dp/1416542744/?tag=pfamazon01-20

That's theistic evolution, not creationism.

 

[CRGreathouse]

In my mind there's no question but that evolution is more reliable/well-known/etc. than big-bang theory. There are still questions about how evolution works, and cladistics is wide open, but the foundations are solid. We see a massive amount of evolution yearly, especially in viral reassortment; the fossil record allows us to see the same process on organisms with longer generations.

The Big Bang theory, on the other hand, is very much in development. While the basics are mostly agreed-upon, there are frequent revisions to our understanding of the finer points. It's not out of question that a major inconsistency in the theory would be found, prompting a more radical re-imagining.

I consider both sound theories, on better footing even than certain practical sciences (like psychology). By all accounts both are more widely accepted than certain speculative fields like abiogenesis and M-theory.

 

[matt.o]

Is the expansion of the universe an observed fact?

Yes, it is. But if you are meaning to imply that the expansion of the universe is the big bang, well...

The expansion of the universe implies a big bang but it is not the big bang. The big bang is a single event that happened a long time ago and cannot be directly observed. It is a prediction of a theory, not a fact.

I don't think I agree with this, russ_waters. The redshift of a galaxy is an observational fact. The explanation for this redshift is that it is due to the expansion of the Universe, which is a natural consequence of the standard cosmology, which is rooted in general relativity.

 

[D H]

The expansion of the universe implies a big bang but it is not the big bang. The big bang is a single event that happened a long time ago and cannot be directly observed. It is a prediction of a theory, not a fact.

I don't think I agree with this, russ_waters. The redshift of a galaxy is an observational fact. The explanation for this redshift is that it is due to the expansion of the Universe, which is a natural consequence of the standard cosmology, which is rooted in general relativity.

You are right that Russ is wrong in a sense, but not in the sense that you think. Russ is wrong in the sense that the expansion of the universe does not imply a big bang. What can be said is that the observed expansion of the universe (a scientific fact) is consistent with the big bang theory (a scientific theory). Scientific theories cannot be proven true. They can however be proven false. The observed expansion of the universe is inconsistent with the steady state model, which is why that model fell out of favor 40 years ago. The big bang theory makes a number of other predictions about what we should see in the universe. What we see so far is consistent with the big bang theory. Some future observation might well disprove the theory, or at least mandate a modification to it.

 

[matt.o]

You are right that Russ is wrong in a sense, but not in the sense that you think. Russ is wrong in the sense that the expansion of the universe does not imply a big bang. What can be said is that the observed expansion of the universe (a scientific fact) is consistent with the big bang theory (a scientific theory). Scientific theories cannot be proven true. They can however be proven false. The observed expansion of the universe is inconsistent with the steady state model, which is why that model fell out of favor 40 years ago. The big bang theory makes a number of other predictions about what we should see in the universe. What we see so far is consistent with the big bang theory. Some future observation might well disprove the theory, or at least mandate a modification to it.

Ah, I am right, but not in the sense you think! The problem is I neglected to remove the part you quoted form my quotes. The part I was objecting to was that russ_waters was agreeing that the expansion of the Universe was an observed fact, which it isn't. The redshift of a galaxy is an observed fact, as is its correlation with distance. The expansion of the Universe is an interpretation of the redshift (and redshift-distance relationship) based on GR.

 

[russ_watters]

You are right that Russ is wrong in a sense, but not in the sense that you think. Russ is wrong in the sense that the expansion of the universe does not imply a big bang. What can be said is that the observed expansion of the universe (a scientific fact) is consistent with the big bang theory (a scientific theory). Scientific theories cannot be proven true. They can however be proven false. The observed expansion of the universe is inconsistent with the steady state model, which is why that model fell out of favor 40 years ago. The big bang theory makes a number of other predictions about what we should see in the universe. What we see so far is consistent with the big bang theory. Some future observation might well disprove the theory, or at least mandate a modification to it.

Could you explain that a little more - I don't see how your explanation disagrees with the word "implies". It doesn't seem to me to address the usage of the word at all!

In any case, are you just quibbling with the historical order things happened? I'm a little thin on who did what and when (and the Wiki seems to contradict itself on the key part of the history...), but I don't see how this really matters. Taken completely by itself, expansion implies a big bang. Ie, if GR hadn't been formulated until decades later, we'd probably still have had a Big Bang theory in the 1930s due to Hubble's discovery alone.