We use cookies to provide you with a better experience. If you continue to use this site, we'll assume you're happy with this. Alternatively, click here to find out how to manage these cookies

hide cookie message
Contact Forum Editor

Send an email to our Forum Editor:


PLEASE NOTE: Your name is used only to let the Forum Editor know who sent the message. Both your name and email address will not be used for any other purpose.

Speakers Corner


It's free to register, to post a question or to start / join a discussion


 

The incomprehensible vastness of the universe


Forum Editor

Likes # 0

Scientists believe the explosion of a huge star near the edge of the observable Universe may be the most distant single object yet seen by a telecope. It's thought that the event occurred just 520 million years after the big bang. This means its light has taken 13.14 billion years to reach Earth.

Now that's what I call a long way. click here to read more

Like this post
john bunyan

Likes # 0

All agreed but there may still be other universes with their own properties that are too far away for us to know about, with other big bangs, and who knows if they have the same physics. Maybe they have a much larger proportion of anti matter than ours.

Like this post
Forum Editor

Likes # 0

where is the 'room' for this vast expanse to expand too and what is it?

It's space, and the room is space itself. As I said in an earlier post,

"We have no idea about how much space there is into which the universe may expand - it might be infinite if we think of it expanding in a spiral of constant radius."

Like this post
rdave13

Likes # 0

john bunyan

I can't remember what program it was on but a professor was sure that the laws of nature, as we understand them, were different in parts of the universe. The more theories that come out then the more questions are created. Is it possible that there are other universes? It's mind boggling.

Like this post
BT

Likes # 0

It's space, and the room is space itself

What I find it hard to comprehend is 'How big is Space?'. I just can't imagine it never ending now matter how 'big' it is. And by the very idea of "bigness" there is the implication of a boundary otherwise the concept of 'big' cannot be defined. Therefore if there is a boundary, what exists on the other side and how 'big' is that, and so ad infinitum.

My head hurts!!

Like this post
rdave13

Likes # 0

So the theory is that the universe is expanding out to space. Suerly that raises even more questions? BT's posting puts it over much better than I could.

Like this post
OTT_B

Likes # 0

"So the theory is that the universe is expanding out to space"

No, that's a complete, and very common misconception. Spacetime is expanding. It does require anything to expand into.

The other midconception which has been inferred is that there may be some kind of barrier or boundary, a bit like a wall. Such a thing is highly unlikely to exist. The 'boundary' of the universe is the edge of spacetime.

Like this post
skeletal

Likes # 1

This is an extremely complex subject and as can be seen from several posts there are many misconceptions.

Firstly, it must be remembered that the big bang theory is NOT how the universe began. It is actually a MODEL, invented by dim-witted humans, trying to make sense of their surroundings. Like all models, it has imperfections, and its great successes. Newton’s theory of gravitation was a model, and very good for most purposes, but it had to be modified by another model called general relativity to patch up a few dodgy areas. It is likely that general relativity will in time also have to be patched up.

When developing a model, experimental evidence is assembled and the best model is chosen to explain, as best we can, the evidence. Sometimes some things don’t quite work, but it’s the best we can do. One “don’t quite works” is the inverse square law which many things in nature obey, until you reach the quantum level and things start going a bit wrong. They may go a bit wrong over vast distances as well. One of my fascinations is why does this sort of thing happen?

One post debates the starting point of theories. Well, another surprise is that philosophically and logically speaking, the very starting point of a theory is UNPROVABLE (I’m talking big stuff here, like the whole of physics). Epistemologically speaking ALL (big) theories/philosophies HAVE to start with an unprovable postulate. If you invoke something to prove your starting point, you have succeeded in making a new starting point which in turn is unprovable. Ironically, this is why religion can co-exist with science, because the starting point of religion is the belief in something called “God”. God is unprovable because He is the starting point. The starting point of science can be elegantly shown to be that the velocity of light is equal to “c” for all observers. Using relativist wave equations Maxwell’s equations can then be developed; of course Maxwell’s equations then lead to vast branches of physics. As ever, the dodgy bit is integrating relativity with quantum mechanics. There is nothing in either philosophy (science & religion) that “disproves” the other; another mistake whereby people try to say “science disproves religion”. It does no such thing; you cannot cross philosophies, you can only be self-consistent within a philosophy. It is however correct to say “you don’t need so and so philosophy” because you can simply chose whichever one you fancy and which best serves your purpose. Science is very useful for many things; religion could be, but has been taken over by people who, IMO don’t understand the basic philosophical principles (I mean, using religion as an excuse to kill people!!!).

As to what the universe is expanding into, this is a very common and understandable misconception; it is not expanding “INTO” anything. Someone mentioned the balloon idea and this is spot on. What our feeble brains struggle with is the thought of four dimensional space time, rather than three dimensions. It is hard to think in four dimensions so the easiest thing to do is imagine you are a shadow with no concept of thickness. You inhabit earth and think it is a 2 dimensional surface. Try to explain how going round the earth you end up back where you started from. It is impossible unless you invoke the third dimension, which of course has no meaning to you because you are a shadow. This is our situation except we think in three dimensions. So yes, one of the models of our universe would have you set off to the “edge” of the universe only to end up back where you started from.

I have to say I’m not 100% convinced that the big bang model is “the best”. I have a real problem with the fact it introduces t=0. This implies that we know the origin of the t coordinate, which in turn means we introduce an absolute frame of reference. The great thing about relativity is that you never have an absolute frame of reference. So, there seems to be a conflict between relativity and the big bang model. However, there are so many things that tie up nicely it is hard to knock it off its perch. Someone mentioned rotation. There is an interesting variation on the equations of motion of the expanding continuum whereby you can represent the same thing by a rotating universe. This gets interesting because if you consider it to rotate rather than “expand” you no longer need t=0. It does introduce a new problem in that there isn’t a good explanation for the microwave background.

Oh dear, there’s always a problem; you see every model does some things well, and others not so well.

And finally, IMO the reason “we are here” is to undertake this sort of thought and scientific exploration. As someone else said, it is what separates us from all other living creatures on earth. Unfortunately so many people take no interest in this and are only bothered about who is having an affair with whom or what latest colour of nail varnish is “in”. With regard to “saving the starving”, think about attacking the countless millions spent on waging war around the world. For me, I’d rather have money spent thinking about the universe than blowing someone’s’ legs off. And don’t forget that the general improvement in man’s knowledge does greatly improve the lives of many people.

Sorry, it is a bit of a rushed post, hope it makes some sense!

Skeletal

Like this post
skeletal

Likes # 0

Absolutely!

We do the best we can with the knowledge available at the time.

I also like the four classical element theory: Earth, Water, Air, and Fire. This is so convincing, and simple and as far as it goes it does help explain what we observe.

Just a shame it’s a bit too simple!

Skeletal

Like this post
Forum Editor

Likes # 0

".....it must be remembered that the big bang theory is NOT how the universe began. It is actually a MODEL, invented by dim-witted humans, trying to make sense of their surroundings."

Precisely, and like all theories it invites examination, and awaits proof. A giant step in that direction was taken by Hubble in the 1920s when he discovered that - contrary to what had been previously thought - almost all the galaxies in the universe were moving away from us. Hubble also discovered that those furthest away were moving faster than those nearest to us.

It followed that if the galaxies were now moving apart they must once have been closer together, and if you made the assumption that they had been doing this at a more or less constant speed they would all have been in precisely the same position at some point. Observations and calculations came up with the conclusion that this point was around 15 billion years ago (now refined to 13.7 billion).

It's all very elegant, but as skeletal points out, it's a model. Models can be tested however - they can be used to make predictions, one of which was that increased density of matter in some areas of the universe would lead to the formation of galaxies.

We understand a good deal more about the universe now than we did 50 years ago, but we also know that there's a great deal more that we don't understand. In another 50 years we may come close to knowing the answers to what happened, although we'll probably still be wondering how it happened.

Like this post
rdave13

Likes # 0

Having read these postings this is what I gather how we try to understand the unfathomable. Create an unprovable point in which the laws of physics, as we understand, will allow. More knowledgee is learnt via telescopes and a tiny bit of space travel. So the base point is changed and we try again. Building blocks of knowledge that might get us there in the end. Does anybody think we have the time to comprehend the incomprehensible before our star finally gives up? Science....fiction or not?

Like this post

Reply to this topic

This thread has been locked.



IDG UK Sites

Windows 10 release date, price, features. The next version of Windows will run on everything:....

IDG UK Sites

An Apple fan's perspective on the Windows 10 launch

IDG UK Sites

Sensor-laden kids' watch with 3G launches in Japan

IDG UK Sites

2014 Retina iMac release date rumours, specs and features: 27in 5K Retina iMac 'launching this mont'......