Thank you very much for the help. Sometimes I wonder how I got this far in life. Ha!

Thank you very much for the help. Sometimes I wonder how I got this far in life. Ha!

Being grooved by science takes up a lot of time :)
(like what you did there btw :))

I think dark matter is on the out side and is drawing out the universe OOOr another universe doing it. Dark matter is just a theory and really hasn't been prov-en to be so. hard call to make but something is pulling it we know but just what this is the question. something is. Or does gravity have it's limitations. we would like to know all the answers but we don't. no PHD here and even them don't know either.

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Cheers everybody
Life is short so don't sip
Beer speaks, people mumble

Throw around ideas and you might come up with someting that makes sense. we listen.

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Cheers everybody
Life is short so don't sip
Beer speaks, people mumble

I think it useful to define "space". What we call space, outer space, interstellar space, cosmos etc, is that which is outside the Earths atmosphere.

Space officially begins at an altitude of 100Km above sea level (Kármán line) but anything less than 160Km will experience rapid orbit decay. The ISS at 425 Km decays at 2 Km/month, Hubble is at 570 Km.

Outer space is between the planets, and interstellar space is between the star systems in a galaxy. It is believed that Voyager One has now left the solar system and entered into interstellar space. Russia and the Eastern Bloc call space travellers Cosmonauts from the Greek words kosmos meaning "universe", and nautes meaning "sailor". The USA and others call them Astronauts from Greek words ástron meaning "star", and nautes meaning "sailor".

Some background and info on dark matter and energy here outer space

Interesting reading Chris. :)

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Cheers everybody
Life is short so don't sip
Beer speaks, people mumble

I thought so as well Grant. I was also trying to visualise the vast distances involved in all this as well and came up with this ready reckoner. Sort of brings to whole thing into perspective a bit.

A light-year is a unit of length used in astronomy, though it is sometimes mistaken for a unit of time. It is equal to just under 10 trillion kilometres (6 trillion miles), and as defined by the International Astronomical Union (IAU), a light-year is the distance that light travels in vacuum in one Julian year.

Julian Year 365.25 days
Gregorian Year 365.2425-days

The light-year is most often used when expressing distances to stars and other distances on a galactic scale, especially in non-specialist and popular science publications. The unit usually used in professional astrometry is the parsec, approximately 3.26 light-years; the distance at which one astronomical unit subtends an angle of one second of arc)

AU = Distance from the earth to the sun
Light from the sun takes 8.32 minutes to reach earth
The nearest star is Proxima Centauri, about 4.22 light years away
Centre of the Milky Way Galaxy = 26 Kilo light years away
The comoving distance from the Earth to the edge of the visible universe is about 45.7 gigalight-years in any direction. 90+ explained

I once heard that the speed of light in vacuum is 186,284.25 miles per second
and in coax wire rg8u is .66 speed of light and so on, so it can be controled to some extent.

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Cheers everybody
Life is short so don't sip
Beer speaks, people mumble

That is fascinating, tell me more.

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Julie, love that song, this is one that I made. Last and only self-promo, I promise.
https://www.youtube.com/watch?v=y5GGRL67E0A

Nice song David!:)

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rOZZ
Music
Pictures

I think it useful to define "space". What we call space, outer space, interstellar space, cosmos etc, is that which is outside the Earths atmosphere.

Space officially begins at an altitude of 100Km above sea level (Kármán line) but anything less than 160Km will experience rapid orbit decay. The ISS at 425 Km decays at 2 Km/month, Hubble is at 570 Km.

Outer space is between the planets, and interstellar space is between the star systems in a galaxy. It is believed that Voyager One has now left the solar system and entered into interstellar space. Russia and the Eastern Bloc call space travellers Cosmonauts from the Greek words kosmos meaning "universe", and nautes meaning "sailor". The USA and others call them Astronauts from Greek words ástron meaning "star", and nautes meaning "sailor".

Some background and info on dark matter and energy here outer space

Interesting reading Chris. :)

It certainly was :) Thank you. I especially liked this bit:

This leaves open the question as to whether the Universe is finite or infinite.

Well actually there were a lot of other bits I liked too - but wouldn't an answer to that question be brilliant!

Yes that was good to read but I still have problems with dark matter, Dose it push or pull? good question. Or does another universe pulling on ours to make a speed change? If dark matter is pulling that would explain it, another universe? where is it.

Since we see in 2D and not 3D might not never be explained, I just don't know. Maybe down the road we can think that way but right now we are blind.

Again that was a very good write up you sent Chris.

update I think I said speed of light was 186,284.25 mph is per sec. :))

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Cheers everybody
Life is short so don't sip
Beer speaks, people mumble

This leaves open the question as to whether the Universe is finite or infinite.

As I have pointed out several times in these boards: As to our Universe: most cosmologists and astronomers think that the universe in finite but unbounded. To grasp this idea consider a two dimensional surface such as a basketball. The surface is finite and unbounded. As it expands it still is finite and unbounded. Does it expand into a 3rd dimension or is there no 3rd dimension in a 2-dimension world?. Food for thought.

This leaves open the question as to whether the Universe is finite or infinite.

As I have pointed out several times in these boards: As to our Universe: most cosmologists and astronomers think that the universe in finite but unbounded. To grasp this idea consider a two dimensional surface such as a basketball. The surface is finite and unbounded. As it expands it still is finite and unbounded. Does it expand into a 3rd dimension or is there no 3rd dimension in a 2-dimension world?. Food for thought.

Nicely put.

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Reality Internet Personality

The speed of light in vacuum, commonly denoted c, is a universal physical constant important in many areas of physics. Its value is exactly 299,792,458 metres per second, a figure that is exact because the length of the metre is defined from this constant and the international standard for time. This is, to three significant figures, 186,000 miles per second, or about 671 million miles per hour.

The Velocity factor in Cat 5 cables is between between 0.42 and 0.72 (42% to 72% of the speed of light). RG-8X Belden 9258 coaxial cable is 82%. When it comes to optical fibre cables we have to take the Refraction Index and the Total Internal Reflection into account. For optical signals, the velocity factor is the reciprocal of the refractive index. This can be up to over 99% Fastest

It's not so much controlled, as limited by it's transmission medium. Whatever, light is damn fast, I think we can all agree on that!

Interesting article Chris, thanks.

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Reality Internet Personality

This leaves open the question as to whether the Universe is finite or infinite.

As I have pointed out several times in these boards: As to our Universe: most cosmologists and astronomers think that the universe in finite but unbounded. To grasp this idea consider a two dimensional surface such as a basketball. The surface is finite and unbounded. As it expands it still is finite and unbounded. Does it expand into a 3rd dimension or is there no 3rd dimension in a 2-dimension world?. Food for thought.

Nicely put.

+1

At the risk of sounding stupid... :) could dark matter itself be inflating...?

The surface of a sphere has a dimension of two because two coordinates are needed to specify a point on it i.e. to locate a point on the surface of a sphere you need both its latitude and its longitude. The inside of a sphere is three-dimensional because three coordinates are needed to locate a point within these spaces.

Now, if you are talking about an expanding universe which can be visualised as an expanding basketball, do you want the distance between two points on the "surface" of the basket ball, or the distance between two points within it? All of which are expanding away from each other.

The surface area of a basket ball at a certain diameter, is a fixed amount and can be measured, as can the volume, as can the distance apart of two points on the surface of it. It is only unbounded if it is capable of inflation.

Assumimg again that this expanding basket ball is our universe, then stars at points on the surface of the ball will move apart further than stars at points within the ball. i.e. the further stars are from the centre of the ball the further they will move apart from each other, as the ball expands. This explains to me why we believe that the rate of expansion of the universe is increasing. I don't think it is. It is just that we are observing further and further away objects, where their distance apart from us is greater.

That is how I see it, and I am probably quite wrong, so I await to be corrected.

Well it is unlikely the universe is actually basketball shaped, so there's your first problem.

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Reality Internet Personality

You know all us folks we try to understand but we do our best. sure kick it around a bit and come with an answer but another question popps too boot.
It's like the book "the never ending story".

sorry i'm felling sick right now, i'll finish later

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Cheers everybody
Life is short so don't sip
Beer speaks, people mumble

It could be a sphere or it might be a torus (donut)

I assumed the Universe was round because it is 98 billion light years across. If it isn't round how can it have a diameter?

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Well quite likely it isn't, but assuming that it is a perfect sphere, were my assumptions basically correct or not.

No.

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Reality Internet Personality

Well quite likely it isn't, but assuming that it is a perfect sphere, were my assumptions basically correct or not.

No.

Ok fair enough, being a physics teacher you would undoubtedly be correct. When you have a few spare moments I'd be interested to know why, and where I went wrong.

Well to put it simply, they have taken that into account and we are talking about such large scales that locally the universe appears to be flat. The questions is how flat is it really? The differences you are talking about would be small, but significant enough to dictate the fate of the universe.

I will see if I can find some links on how they do the calculations.

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Reality Internet Personality