Vegas & The Aftermath - Diary

[tikay]

The reason the Hammersmith Flyover is crumbling is because they kept gritting it in winter even though they didn't need to.

The people that built it were well aware that if water got into the steel cables within the flyover, that would be bad news. Salt water is even more corrosive so to prevent this getting in, they put underroad heating in under the surface, so that it wouldn't have to be gritted in winter and any ice or snow wouldn't build up.

Unfortunately, somewhere along the way, the instruction manual for the flyover seems to have gone missing and it was gritted just like any other road - years of salty runoff got inside and made it all crumbly.

EDIT: After a bit of a Google it turns out that the heating system was originally switched off by the council as the bill was so high, so it was paid by the London County Council. Then, at some point, the heating broke, though no one seems to know when.

All true, but things like bridges & tunnels need to be built above the level of incompetence of those who look after it.

Brunel designed & constructed the Maidenhead Bridge over the Thames in 1838, for his GWR. It was designed to carry the load of two railway tracks, despite being the longest "flat arch" brick built bridge ever. Later, they DOUBLED the tracks to 4, & so doubled the weight it may have to bear. It is still doing it's job to this day, & is virtually maintenance free.


http://en.wikipedia.org/wiki/Maidenhead_Railway_Bridge

[tikay]

I must work with some incredible actors. I told them the 29,000 bridges stat and they came across as nonplussed.

Would it help if I Posted a few more Videos of Tube Trains going through tunnels?

In some of them, you can see the light at the end of the tunnel.

[tikay]

One final attempt re the astronomy stuff. Wouldn't do this other than there are some mind blowing numbers here:



This little fellow is the Pinwheel Galaxy. You are seeing it about 21 million years ago, because that's how long the light takes to get to us. It is about 70% larger than our Milky Way but has 10 times as many stars in it.

Remember the stat about that nebula where if we stood at either end it would take 2 years for me to see you waving? With this galaxy, it would take 117,000 years for me to see you waving.

It is a spiral galaxy, but we can see it virtually straight on.




This is the Sombrero Galaxy (sounds like an ice lolly). 29million light years away.

It is also a spiral galaxy, but it is side on. It has a ring (like Saturn) that goes all the way round the entire galaxy.

The black hole in the middle has the equivalent of a billion of our suns in it. A billion.

Mind-blowing, if true, yes.

How can we prove it takes 10,000 light years for something to travel from A to B?

[kinboshi]

Prove?  c (the speed of light) is a universal physical constant, and is central to a lot of the physics we know and understand.  Plenty of evidence that has been reviewed and examined by physicists backs up the idea of a 'speed limit' in the universe.

http://en.wikipedia.org/wiki/Speed_of_light

Distances of objects in the universe is measured using observations of 'redshift' (amongst other things): http://en.wikipedia.org/wiki/Redshift

[Tal]

What boshi said.

It is a bit like the Doppler Effect. You know, when an ambulance is going past, you hear the NeeNaws get lower pitched as the ambulance pulls away from you? That's because the sound waves get dragged out and, resultantly, the sound you hear as it wallops against your ear drum is of a lower frequency.

With electromagnetic radiation waves, it's the same sort of thing but, rather than it sounding lower, the effect with these waves is that it is gets redder; it gets closer to the red end of the light spectrum (ROYGBIV and all that).

I can't confess to understanding it all, but it does give some impressive sights, concepts and numbers.

[tikay]

What boshi said.

It is a bit like the Doppler Effect. You know, when an ambulance is going past, you hear the NeeNaws get lower pitched as the ambulance pulls away from you? That's because the sound waves get dragged out and, resultantly, the sound you hear as it wallops against your ear drum is of a lower frequency.

With electromagnetic radiation waves, it's the same sort of thing but, rather than it sounding lower, the effect with these waves is that it is gets redder; it gets closer to the red end of the light spectrum (ROYGBIV and all that).

I can't confess to understanding it all, but it does give some impressive sights, concepts and numbers.

Better - stick to NeeNaws & I can understand that.

[RED-DOG]

One final attempt re the astronomy stuff. Wouldn't do this other than there are some mind blowing numbers here:



This little fellow is the Pinwheel Galaxy. You are seeing it about 21 million years ago, because that's how long the light takes to get to us. It is about 70% larger than our Milky Way but has 10 times as many stars in it.

Remember the stat about that nebula where if we stood at either end it would take 2 years for me to see you waving? With this galaxy, it would take 117,000 years for me to see you waving.

It is a spiral galaxy, but we can see it virtually straight on.




This is the Sombrero Galaxy (sounds like an ice lolly). 29million light years away.

It is also a spiral galaxy, but it is side on. It has a ring (like Saturn) that goes all the way round the entire galaxy.

The black hole in the middle has the equivalent of a billion of our suns in it. A billion.

Tal. Are we seeing a magnified view of those galaxies? (magnified from our viewpoint that is, I know they wouldn't fit into the picture at actual size.)

[kinboshi]

Tom, it's just an image via a telescope (I think).  A bloody good one though!

[tikay]

Nobody want to discuss District Line tunnels?

[RED-DOG]

Tom, it's just an image via a telescope (I think).  A bloody good one though!

I understand that, so at what magnification (ish) are we seeing it via the telescope?

[RED-DOG]

Nobody want to discuss District Line tunnels?

You have tunnel vision.

[Tal]

It is the iTelescope that these images were taken from, but here's the website I got the details from:

http://www.chessbase.com/newsdetail.asp?newsid=8862

Scroll down from the chess puzzles if you like.

The first image is about the size of the moon but you can't see it with the naked eye because it isn't very bright.

[kinboshi]

Tom, it's just an image via a telescope (I think).  A bloody good one though!

I understand that, so at what magnification (ish) are we seeing it via the telescope?

This is the telescope: http://www.itelescope.net/telescope-t11/ which apparently has a resolution of 0.81 arc-secs/pixel...

[RED-DOG]

The telescope details are too complex for me but my point (When I make it) will remain the same.

If we are looking through a powerful telescope, won't we see the light sooner, i.e. so that 20 light years becomes 19.9 light years or something?

[Tal]

The telescope details are too complex for me but my point (When I make it) will remain the same.

If we are looking through a powerful telescope, won't we see the light sooner, i.e. so that 20 light years becomes 19.9 light years or something?

Light can only travel at the speed of light. It can only get from where it is to your eye as quickly as light travels, so I don't think so, no