Funny to think that this, being 10 years old, might already be out of date on some things. Probably not more than details, though, and it's still very interesting.
Here's a slightly newer one, I think it's more or less the same thing.
Astronomy & Space Exploration
- Thread starter MrMarcello
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Funny to think that this, being 10 years old, might already be out of date on some things. Probably not more than details, though, and it's still very interesting.
Here's a slightly newer one, I think it's more or less the same thing.
somewhat related.
You are right. It wasn't that long ago when the thinking about the Big Bang was that it happened from nothing.
My current understanding of the thinking is that the big bang was either the start or end of Cosmic Inflation.
And that our universe is not the universe but one of maybe an infinite universes which are continuously forming and dying.
I read about it but, like many struggle to comprehend the sheer scale of things.
Cosmic inflation is definitely post big bang, as it's an integral part of the early Universe. There are interesting theories about infinite Universes and all that, but it seems like it's probably completely unknowable to us, and mostly amounts to speculation.
Good to talk to someone who has the intelligence to even think about these things.
I have read that the big bang was either before, after and even was cosmic inflation.
The whole science behind cosmic inflation is absolutely fascinating and is an evolving subject.
I still cannot really get my mind around scalar fields. Especially how they could operate at the quantum level.
Nothing is as it seems.
That's true and there are a lot of interesting theories about the impact of NASA's missions.
Here's one that blows my mind.
At some point, in several billion years time, galaxies will be pushed so far apart from each other that they won't be able to see each other any more. In other words, the distance will be so great that even light from other galaxies won't be able to travel far enough to be visible.
This could well lead to intelligent life evolving on some distant world in the Milky Way and believing that our galaxy is the entire universe.
Although by this point I guess it will be 'Milkdromeda'
I love this stuff.
Same it is truly wonderous. If I could live my life over (and if I was more intelligent) I'd love to have gone into the field as a career.
Same, man. I could sit for hours watching documentaries and listening to podcasts on the wonders of space and astronomy. How everyone doesn't find the field fascinating is astonishing to me.
Never too late to begin!
Maybe as an interest yeah but that ship has sailed as a career - mortgage needs paid now!
That is damning analysis. Makes a couple of Nobel laureates look altogether foolish.
She also made a lay person video of the topic
Although I am retired, I have an almost insatiable interest in all matters Cosmology. I have read a large number of books and of course watched the Prof Brian Cox programmes. His books on the universe are my main references.
To me, the biggest problem is not always the understanding. It is in keeping up with the pace of our developing understanding of the cosmos.
And in particular, quantum mechanics.
This is the most fascinating subject and I am truly in awe of the many brilliant scientists. Not just the current ones, but those of the past.
And here is a counter video explaining why dark matter is still a thing because it is based on more than just the supernova observations
Would love to see a rebuttal
It's not so much that they are pushed so far apart, but that they are being pushed so quickly apart that the light from those galaxies will eventually be redshifted out of our (or possibly anyone's) ability to detect it. Though I suppose "far part" and "quickly apart" are directly related in this case.
But yeah, that's a very interesting thing to consider, and which is also brought up in those videos I posted (at least one, I can't remember if it's in the second as well). They're going to arrive at the utterly wrong conclusion that not only is their galaxy the Universe, but that the Universe is static and possibly eternal. And it'll seem entirely logical to them, because they probably won't have any way of figuring out about the Big Bang either.
Of course, they're going to have a great big galaxy to explore if they want to, so it's not all bad.
For anyone interested in this stuff: I highly recommend the Walkabout the Galaxy podcast. It's (sometimes) heavy on the science while still being approachable for amateurs like us. I'm fairly sure they've already discussed the Dark Energy stuff @B20 brought up, for example (yep, here it is). Note that their site isn't entirely up to date on podcasts, just use whatever tool you otherwise use for podcasts. If you don't have any, I suggest Pocket Casts, purely because that's the one I'm using. They're also on Spotify.
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I don't think, that these accounts contradict each other by as much as it might seem.
In the last few minutes of the interview with Prof. Sarkar, he spells out the issue.
"(...) this to me reflects a rather disturbing fact, that the analysis of the data is rather specialized. Very few people know how to handle these catalogs (...). Its largely a black-box. (...) There have been far less critical assessments of the procedures that have been used than there should have been."
At least for now I think this is another example of bad/lazy handling of data, because it was convenient. The group of people who process/prepare the data is very small and nobody actually checked if their work sound. I suspect that it is very easy to make mistakes and that many choices how to error-correct/prepare the data are not as well-defined as one might think. Nobody seems to care too much, because the existence of dark energy is scientific consensus (for good reasons) and the data affirmed all their priors. Physicists are prone to group-think and/or "tunnel-vision" just like anyone else and it might be embarrassing to admit basic mistakes. At this point in time we don't know enough to say much if this has substantial consequences and I wouldn't assume that it has. It has to be analysed to fully understand what happened and if any mistakes happened, that have substantial consequences.
I think this type of situation is way more common in science than people realize.
It's crazy to think that, at some time galaxies will be so far apart we won't be able to detect them
as stated, I absolutely love this stuff.My very basic understanding is that despite the vageries of our current understanding, all of the models of our universe show that there has to be significantly more Matter than that we know about.
And that is because the Matter than we know about is far far too little to be responsible for its expansion. It is believed that we only know of some 4% of the required matter.
And expansion is a fact so something has to be driving it.
Cassini had taken some of the most beautiful pictures I've ever seen. Saturn is really stunning.
It’s absolutely gorgeous, you’re right. When I was watching the Brian Cox programme on the planets, the episode covering Saturn showed both its beauty and its incredible story.
I wonder how much of post processing has gone into this. The rings looks so smooth.
Wish I saw this thread 7 years ago. This is me and always has been.
Was just sat on toilet and thought how many seconds in the age of the universe and is based on it being 13.8 billion years old.
I make it 4.343x10^17s
Had a few beers though.
Was just sat on toilet and thought how many seconds in the age of the universe and is based on it being 13.8 billion years old.
I make it 4.343x10^17s
Had a few beers though.
Which is 434 quadrillion. I begrudge using google cus am teaching myself algebra and scientific notation cus need to push myself to the next level.
Digress. Do we know when JWST will be being launched?
Digress. Do we know when JWST will be being launched?
Nice to see a Massimo post on here.
Imagine the pictures James Webb is going to provide us.
Given its history, everything points towards the Ariane blowing up during the launch.
In case anyone's interested this site is showing the entire Apollo 13 mission in real time: https://apolloinrealtime.org/13/
Included real-time elements:
Included real-time elements:
- All mission control film footage
- All on-board television and film footage
- All Mission Control audio (7,200 hours)
- 144 hours of space-to-ground audio
- All on-board recorder audio
- Press conferences as they happened
- 600+ photographs
- Searchable transcript
- Post-mission commentary
It is a truly fascinating subject isn't it.
And there has been so many things that have been discovered recently.
How are you at grasping quantum mechanics.
Definitely. I've always been ok with quantum mechanics as I accept that the laws of physics are different on that scale so it doesnt need to seem intuitive. It's really cool too.
https://phys.org/news/2014-01-quantum-mechanics-efficiency-photosynthesis.html
Many thanks.
It is quite amazing that plants are so efficient in processing sunlight.
They can, almost instantly convert sunlight into energy.
Whereas animals cannot do this, and have to eat the plants to gain energy.
Another fascinating thing is the way that plants choose to absorbe specific parts of the light spectrum.
They tend to absorbe primarily the red lower frequency and blue higher frequency ends in order to maximise energy absorption. And of course that gives them the characteristic green colour.
Excellent.
The whole American space programme is absolutely fascinating and even now must rank as mankind greatest achievement.
To be able to go from the pretty low level of capabilities when President Kennedy made his incredible speech to actually fulfilling that committment just over 8 years later was in itself outstanding.
But we must remember that the terrible capsule fire took almost 2 years out of that timescale for NASA.
It is a fact that each particular experiment had to run almost in parallel.
And to achieve that defined outcome, each and every experiment had a be 100% successful, with no opportunity to repeat.
And it had to be done in public and against the background of the awful Vietnam War.
And with primative levels of computing power.
And where are we some 50 years later???
A good book is Hawkings the Grand Design for the basics of quantum physics. I've always been into space and how the world works since a young age. I'm up to p17 of this thread around the time of LIGO gravitational waves discovery.
Wow. Looking back at p17 for example, there are some seriously clever people contributing to this thread.
I must admit that I am more comfortable reading things that I can more easily understand.
Much of my understanding is based upon the Brian Cox books about the wonders of the universe, solar system and nature.
I have read a couple of books by Stephen Hawking, but cannot say that I understood them.
But I will have another crack at The Grand Design.
Taking the word Design, seems to infer some form of creation.
Whereas, our universe and everything in it evolved as opposed to being created.
Or am I taking the title too literally.
I've got so much to offer in these early pages but it's too long ago to respond now. C'est la vie.
I'm learning algebra from the ground up to help myself understand all this more intimately but the principals I've always been ok with.
And yea design doesnt mean god. There is no god. It is a great book, the holy grail of physics is to unify basically gravity with the 3 other forces to form a unified theory of the universe. The other 3, weak/strong nuclear force and electromagnetism have a force carrying particle associated with them but gravity hasnt. So they all work in newtonian and quantum physics but gravity is the odd one out as there is no force carrying particle. But black holes exist in the very tiny world of the plank scale as a singularity. This isnt resolved in my hero Hawkings books however.
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It's been talked about on the Caf, probably in this thread too, but imagine where would be if not for the Dark Ages and other attempts to the thwart science and culture over the past centuries.
The Dark Ages is a bit of a myth, actually. It wasn't really the scientific valley it's made out to be. In general I'm quite wary about making these sorts of claims about history, since it's basically impossible to say with any kind of certainty.