There is only One Big Bang...

For those of you in the know, ignore this, as it a return to the point of this Blog - to explain in simple terms things scientific.

Everybody has heard of the Big bang. And it's not Yuko, as she is far too small.

The Big Bang is supposed to be the beginning of everything. But is it not as simple as a big explosion.

We came to this conclusion because we discovered the Universe was expanding (See the Cepheid variables post).

So, we turned back time and thought backwards and it was obvious that in the past everything was in the same place.

And it went "Bang!".

However, it's not as simple as that. The equations tell us that not only everything was in the same place at the same time, but time and space were too. Another way to say this is that there was literally nothing "outside" the Big Bang.

The best way to illustrate this is to think 4-dimensionally. Very hard to see, but the model usually used is that the 4 dimensions of spacetime can be represented in three.

By a balloon. An inflating balloon is easy to see, and if you have dots on it to represent the galaxies, it is clear to see that all the dots "move away" from each other, BUT there is no "center" that they are moving away "from".

The surface of the balloon represents both time and space "expanding".

So how did it start? That is another post, however.

The balloon model has been going for years, but not many people outside science circles have heard of it.

There are three models of this expansion. 1. Open (the universe will continue expanding forever)

2. Closed (the universe will stop expanding, slow down, and gravity will pull everything back into a "Big Crunch"

3.Neither. (The universe will stagnate and end up neither expanding nor crunching)

And now the time for enlightenment. How many people have realised the significance of my blog url, www.gnabgib.blogspot.com??.

It's another phrase coined by us for scenario (2) above! "GNABGIB" is "Big Bang" backwards, and both phrases are used! Gotcha!

As promised.....

Just a little calculus off the top of my head. As far as I know, this is completely original.

I have never seen this in any of the textbooks.

It goes further....

In part 2, the brackets are very important, because of the way they are envisaged. I only give one interpretation.

There is another, giving a completely different answer.

Maybe I will give that other interpretation in another post...

Space, the Final Frontier...

(The Andromeda Galaxy yesterday)

Ever paused to consider exactly HOW we know the Andromeda Galaxy is the nearest galaxy to us?

The answer to that is actually in debate in some circles.

In fact, the whole "distance measurement to other heavenly bodies" is an entire subject up for debate amongst certain people.

It may be useful therefore, to provide a brief history of how we got to this position.

Way back when we discovered the "wanderers" (planets) we used Newton's Laws to determine how far they were from us. This done, we then used those same laws to conclude how far the nearest stars were from the difference between their apparent "brightness" and the brightness we should expect them to be by virtue of their "spectra" (plural of "spectrum), because different sized stars gave off different kinds of light, once again, according to Newton's Laws.

Then comes the Bone of Contention.

The Cepheid Variables.

These particular stars pulsated. And this pulsation period (how often they went off and on) was related in a very simple way to their brightness. SO! NOW we had a tool to measure far bigger distances.

Then someone with an enormous telescope noticed Cepheids in Andromeda, and from the rate at which they switched "on" and "off" came to the conclusion that Andromeda was a massive distance from us, 2.5 million light years (a light year is the distance light travels in a whole year) from us.

Maybe a few other galaxies were discovered using the "Cepheid variable yardstick", but from then on, the galaxies were so distant that these stars just could not be seen.

Then came another breakthrough. Edwin Hubble realised that the Universe was expanding, and that all galaxies were receding from each other. It was at first thought that they were all receding from EARTH but a bit of quick fourth-dimensional thinking dispelled that. The idea was that the Universe could be envisaged as sitting on the surface of a balloon, which was being inflated. Any point on the balloon could be seen to be receding from every other point, so there was no "centre" to the expansion at all.

Anyway, once this "expansion" hypothesis had been accepted, a new yardstick came into play - the Redshift.

It is the same effect heard when police sirens approach you, pass you, then recede from you. A definite change in pitch is heard to the notes emitted from the siren. This is called the "Doppler" effect. The same thing happens to light, only with light, it is what you SEE that it affected. And what you SEE, as something goes away from you, is a shift of the spectrum towards the red end. Or, if it is coming at you, the blue end.


This "redshift" was calibrated with the known galaxies whose distance we knew from the Cepheids, and then extrapolated to include far more distant galaxies. Thus was born the "Hubble Constant" This is a measure of how fast the Universe is expanding, mostly based on those Cepheid Variables we can actually see.

It is currently about 80 km per second for each meagaparsec further out the galaxy is (a "parsec is about 6.2 light years). In other words, if we find a galaxy that is moving away from us at 80 km per second (determined by the redshift) then if we find one that is receding at 160 km per second, it is roughly twice as far away.

The Hubble Constant started out at more than double what we think it is now. To this day, no-one knows its true value simply from lack of data.

Anyway, to the main point. All these distances rely on correlation between brightness, the Cepheids, and redshift.

The method with the least data is that with the Cepheids. In other words, we are still not quite sure exactly how far things are "up".

Then there are the Quasars. These are extremely bright objects that some of us thought were stars at first (they were called "Quasi-Stellar" radio sources, the "quasi" taken to mean "likened to", from which sprouted the name), but according to their redshifts, were GI-normous distances away.

Nowadays, the current view is that they are the nuclei of very distant galaxies that are very active. It was once thought that, since they are about 13 billion light years away, and that the age of the Universe is about 14.5 billion years, that what we might be seeing was the Big Bang itself.

There have even been theories based upon the fact that quasars are no more than local star (in our own galaxy) whose redshift is due to something else.

The entire point being, the measurement of distances in space is sketchy to say the least, a point glossed over in many books on astronomy.

Recently, a new yardstick has emerged - Supernovae (what happens to a star when its nuclear fuel runs out? It goes bang!). There are very definite equations describing what would happen to a star and how bright it should be when this happens.

So, as before, the brightness of a supernova BANG will be an indication of how far away it would be. Theoretically, at least. Unfortunately, these are so rare, we still await salient data to test this out.

The conclusion?

E.T. may be nearer than at first thought!

"If You Can Meet With Triumph and Disaster...

...and treat those two impostors just the same".

are words from Kipling's "If", those that adorn the threshold to the Centre Court, Wimbledon Lawn Tennis and Croquet Club, London SW19.

Never have those words meant more than in Last Sunday's epic Men's final between Roger Federer (Switzerland) and Rafael Nadal (Spain). It is of interest to note that Rafael Nadal does not read his lines, but has seemingly memorised them, as opposed to Roger Federer, who merely reads his (admittedly, the longer portions, but nevertheless........)

It went to five sets, was the longest ever final, was the latest final ever to finish at 21.15, and most commentators agree it was the most dramatic ever, and the BBC very wisely asked the two players to recite poem to be broadcast prior to their fantastic battle. Four hours Forty-Eight minutes of absolute delight cannot be condensed into one video, so the poem is presented here.

I may add that having seen it BEFORE the match, there was still a tear in my eye.

THIS is theatre as only the BBC know how to do.....