Why are scientists so confident regarding the specifics of the universe?

I think it’s important to keep in mind when you watch these videos or documentaries the people involved in making these really have to dumb things down so it can be consumed by the average Joe.

For instance most people don’t understand what a singularity is despite being avid fans of astronomy documentaries.

If you’re interested, it’s a fascinating story. Scientists noticed that if you heat up objects, they glow - and there’s a pattern in the frequencies of the glow. Each kind of thing (each element) has a pattern of frequencies that show up when that thing is heated. Furthermore, when you shine a light through a cool cloud of a substance, light at those frequencies is absorbed (doesn’t make it through the cloud). One set of scientists focused on figuring out why that pattern of frequencies existed, by studying matter on Earth, and uncovered the explanation of how electrons are distributed around atomic nuclei. Another set of scientists studied the light from stars (and other objects in the sky) and deduced what they are made of. A third group of scientists observed how brightly stars shine and at what frequencies to figure out how the substances that make up stars actually make the stars bright - and that idea of how the stars shine could be verified by blowing up hydrogen bombs on Earth, too. No doubt, I’m missing vital details, but it’s all incredibly cool, and it all fits together quite well (when there’s a part of science that doesn’t fit together very well with the rest, we generally find that a few details later, the pieces snap together even more satisfyingly).

And for a more thorough response:

Are you missing a bit of the sentence there? Such as “… containing fossils of Martian bacteria.”

Seriously? The ‘irreducible complexity’ of the eye thing?

Not only has this been debunked by demonstrating a plausible development path where each ‘incomplete’ stage of the eye would still be useful, but also, organisms with just such ‘incomplete’ eyes exist to be observed in the natural world today.

I have enough experience with these people to state you are correct. And the ones with degrees, and doing legitimate research, are always experts in a different field from evolutionary biology. And none have ever published on creationism in legitimate journals, even if they have published papers on things they know about in these journals.
Ham couldn’t read and understand a legitimate paper with a Classics Illustrated edition. And Kent Hovind is even worse.

Hovind is pretty clearly one of the dishonest, not just ignorant ones - one of his common tactics is quote-mining - that is, taking something written by someone else, and extracting an out-of-context quote that makes it sound the exact opposite of what the full quote is saying.
You can’t do this repeatedly by accident - you have to understand the meaning of the full text in order to precisely strip away parts to reverse the meaning.

I very mildly disagree with this. You are of course right that data inspires theories; that the whole point to a theory is to explain what we see.

Still–at the heart of any theory is a kind of unsupported supposition. One that arrives by, essentially, intuition. Einstein guessed that gravitational acceleration and inertial acceleration were the same thing. It was plausible, certainly–it didn’t contradict anything. But at the same time there was no reason to believe it must be true. Only after the consequences of that supposition were worked out and experiments performed can we infer that it was probably a good supposition after all.

Or, as the great Feynman put it: “We look for a new law by the following process: First, we guess it”

A comparison: scientists are after the truth, using data, peer review and being ready to adjust their conclusions; mass-market newspapers want readers - using exaggeration / lies, appeal to base instincts and always satisfying the political desires of their owners.

A right-wing newspaper here in England would salivate if they could have a headline reading:

‘Immigrants insult Royals and cause inflation’

The water question is an interesting one, as other people have pointed out. The first thing to note is that probes have sampled various comets, to try to find out (amongst other things) the isotopic composition of their water. So we know a bit more about comets than we do distant stars and galaxies, since comets have been directly sampled.

The probe Giotto sampled Halley’s comet, and found that the isotope composition of the water was too rich in deuterium (i.e. it contained too much heavy water), so the source of (most of) Earth’s water probably wasn’t from long period comets like Halley.

Then the Herschel probe sampled a much closer-orbiting comet called Hartley 2; this comet had water much more like Earth’s, so it seemed likely that Earth’s water largely came from shorter period comets.

A third sampling, from a comet called Churyumov-Gerasimenko, also a short-period comet, was quire different from the Hartley 2 result, and contains too much deuterium to be a good source for Earth’s oceans. This means the source of water is an open question again, and the most likely source is now thought to be icy asteroids from the early asteroid belt.

Exactly. This is still an area of ongoing enquiry. To test the asteroid theory we’d need samples from asteroids beyond the so-called ‘frost line’, where water is abundant. We haven’t got these samples yet. Let’s see what happens when we do get samples of this kind.

In general, science works sort of like a Sudoku. While it may be that there’s only very few “facts” to look at, getting those facts to jibe with one another can restrict down the possible answers to something very specific. It’s just a matter of doing enough work, calculations, and peer reviews to slowly work through all of that.

But, likewise, tracking through how some other person got from 5 filled in squares to a full set of 81 does mean wading through quite a bit of tedious logic and note taking. It’s not always going to be straightforward to follow unless you put yourself in the same position and work the problem yourself.

Whether the scientists got it right, or not, I generally wouldn’t be able to say and that’s liable to be true for you as well. But I suspect that if you do simply Google and check the Wikipedia for answers on the specific questions, it will at least give you some information on the general facts that they started from and maybe some sense of the logic they used. Worst case, you can always ask, here, in the GQ for someone to help explain.

And, ultimately, whether they got it right or not; the fact that they’re trying to follow some logical process of tackling the problem at least gives the answers that they give us a lot more foundation than, say, plonking your finger down on some random page of Nostradamus’ Prophecies and trying to find some answer from the poem your finger struck. It is still, certainly, your best bet.

An interesting aside is that Earth doesn’t have much water. Several vastly smaller bodies in our solar system alone have more water than Earth.

https://www.reddit.com/r/space/comments/hro91j/pluto_and_five_moons_in_our_solar_system_have/

Quite possibly we lost a significant amount of water during the impact that formed the Moon. If that impact had not occurred, our planet might have been covered in a continuous layer of ocean with no land at all.

This might have prevented easy abiogenesis on our planet, but this is another debatable question.

I like that analogy - for one thing, in a Sudoku, even if you don’t know whether one particular square should be a 1, a 4 or a 5, you know for sure that it’s not a 9. Likewise, we may not understand some aspect of heat flow, but we’ve eliminated phlogiston

I’m late to this thread but I think Stoid is asking some really cool questions — and Andy_L and others have given some really great answers about how we know what we think we know that I’ve learned a lot from.

A lot of our knowledge rests on the idea that if something is true here on Earth, it will be true in our sun and in distant stars and galaxies. So if hydrogen emits or absorbs particular colors of light in a gas cell on my desk, and I see that same pattern in data from the sun or from a satellite, I know I’m looking at something with hydrogen. If the pattern is Doppler-shifted, I know its source is moving relative to me.

Quantum mechanics provides exquisitely precise descriptions (verified by terrestrial experiments) of these patterns of light for all of the elements — and for many molecules! It also tells us about how material behaves when it gets hot, like the plasma in the sun, or dense, like the Fermi soup of white dwarf stars. And once we have a basic understanding of what stars are made of, how their masses and temperatures are distributed, and approximately how they evolve, we can try to model them and then compare the predictions of our models with what we observe in the vast sky. This allows us to estimate, say, the age of the universe.

It’s not magic, but it’s kind of magical.

I think this is something that is frequently overlooked by lay people - for example when discussing the fundamental speed limit of the universe, you’ll often hear people say ‘well, people once thought that they would suffocate if trains went too fast and they were wrong, so maybe you’re just wrong about the speed of light’.

Except the train suffocation thing was just an idea they made up afresh and was simply proven false. Any new theory that displaces current models about light and relativity can’t simply render it false, it also has to explain why it appeared true; why we had to account for that apparent truth in various contexts (like GPS satellites have to account for time dilation, I believe); why we were able to create technologies based on the model.
Everything that currently confirms the current model still has to work in any newer model. That’s possible if it turns out that the current model is merely a close approximation of part of a bigger picture, but we aren’t about to discover that everything we observed is wrong, because it happened.

Having read this entire thread (so far) I think Stoid has awkwardly

  1. admitted he’s not a scientist
  2. asked “how are scientist so certain?”
  3. used details from astrophysics as an example
    He wasn’t fielding the question from an anti-science (i.e. religionist) position and, in general, the answers for him have been applicable to the various fields of science in general, not just astrophysics.

Several responders have used this phrase and I feel the need to object, weakly. To keep it light, let me just paraphrase professor emeritus Dr. Henry Jones Jr.: “We’re not looking for Truth, if you want to deal with Truth the religious studies department is down the hall.”

Scientists, on the other hand, are ultimately trying to be able to discover, model, and predict reality. There’s no value there – it’s not good or evil or comfortable or strange, there’s not even normative comparison.

If we heat Hassium to ### degress C it will begin melting. If we heat Hassium to ### degrees C it will begin vaporizing and that vapor will be ____ color.

It occurs to me that a key reason we think our scientists are in opposition to religionists is because, ultimately, an intelligence behind all the workings of reality can, by definition, be capricious and therefore throw any predictability out the window.

…and this, again, is a key difference between religion and science: when presented with evidence to the contrary, a scientist will take the new evidence into account and either explain why it fails to fit the model or develop a new model to fit both the old and new evidence. When presented with evidence to the contrary, a religionist will dig in and insist the religious explanation presides.

And then there are the rest of us, who are neither religionist nor scientist. Given the explanations from both sides, some are inclined to accept the religious paradigms – they’re more comforting and they are acceptable enough. But scientific paradigms are also ‘acceptable enough’ for those of us who lack the brains or inclination (or time or money) to delve deep into the literature.

And I suspect I’m not unique or even rare in being simply more inclined to ‘have faith’ in the power of mathematics and its application to the various scientific fields than to put my faith in the capricious vanity of theism. For me (and probably others) there is essentially a blind faith in science (or perhaps it should be a collective Science) and I’ll admit to having wrecked many discussions with such a statement: Yes, there are those of us who have blind faith in science. Whether a person’s faith in science exceeds his or her faith in religion is probably going to be as varied as there are people.

I argue, though, that while religion historically helped humans cope with their world in the past, science has helped humans cope with and control their world in the past, present, and future. Applied religion is social influence and politics; applied science is physics, agriculture, and so much more which also influences society and politics!

–G!
{I’d better stop now, I think I’m rambling}

Thanks!

Good points all. Not rambly.

FYI, @Stoid is a woman. As I’m sure you’re aware, “they” is the SDMB culturally preferred pronoun unless you’re 100% sure.

Or attack the evidence!

I can say it as a joke, but it is also legitimate. Sometimes the new evidence is wrong, be it from flawed experiments, flawed analysis, mistakes, or even fraud. Of course, there is often disagreement over whether or not the experiment was flawed, or the analysis was wrong.

When outsiders look in, they may see a bunch of scientists fighting, which can make the outsider wonder how the scientists can be so confident when they’re still arguing about how things work. However, the scientists all agree on the big picture, and are arguing over details that may not make much difference to anyone outside of the field.

A semi-made up example: A vaccine study may show a spike in blood pressure for some people with certain risks, but another study may not find the same problem. Publicity from the arguments over the spike in blood pressure may make the vaccine seem unsafe, while all of the scientists would agree that it is extremely safe, they’re just trying to work out if the first study means extra precautions need to be taken for some people, or if the results were just bad luck (or something else), and, as the second study shows, the spike in blood pressure is not an issue.