Horizon BBC 2 TONIGHT... INFINITY

[skye at night]

I don't think my wife could handle thinking that there might be more than one of me!!!

Steve

[TheThing]

Good programme. DVD'd it and watched it last night, although it kept me up for ages trying to work out how many zeros in a google-plex!

I particularly liked the bit about the biggest number - the Graham - which ends in 7 and that's all that's known about it.

[Psychobilly]

It was ok but I thought "how long is a piece of string" was better...

Don't forget light fantastic on BBC4 on Iplayer here...

BBC iPlayer - Light Fantastic: The Light of Reason

Peter...

[acey]

kept me up for ages trying to work out how many zeros in a google-plex!

There are a googol zeroes in a googolplex.

As to how many in a Googleplex, I dunno - it's the name of Google's HQ in California.

Googleplex - Wikipedia, the free encyclopedia

Googolplex - Wikipedia, the free encyclopedia

[astropete]

the prog was great, i couldnt understand a word of it, but i still watched it. they say the googleplex is the largest number known, well how about a googleplex and one?

[red dwalf]

went stright over my head after 10 minutes and i fell asleep

[Macavity]

A bit waffle-y? Some interesting higlights: The "infinite hotel"... Increasing numbers may eventually return to zero... How far am I from my (multiverse?) "doppleganger". Strangest moment: Camera lingering on some professors (sandle-clad, naturally!) restless FEET? At least I THINK that was the same program... I tend to doze off too!

[keef_uk]

i keep meaning to catch it on iPlayer - I did watch that light one and enjoyed it. guess ill never be that clever!

[Rusty Strings]

Was an ok episode, as soon as logic seems to be abandoned (to me anyway) I rapidly lose the plot and enthusiasm, I also found the gratuitous Steven Berkoff very annoying too.

John

[acey]

I missed the prog but if they said a googolplex was the largest known number they clearly mis-spoke - maybe they meant to say it's the largest number with an official name, though even then they would have been wrong as the Skewes number is a lot bigger:

Skewes' number - Wikipedia, the free encyclopedia

But please can we stop being overwhelmed by the Google mega-corp into mis-spelling the good-old googol, which has been around since 1938!

Googol - Wikipedia, the free encyclopedia

[Ant]

I watched the program on Iplayer last night, very interesting - but most of it over my head.

They said that the largest number was something called "arthur's" number (or it might have been Graham's number... something like that).

It it a digit with a googolplex of digit's after it. It took the guy several minutes and a rather large formula to work out that the last digit was a 7!

Ant

[acey]

It's bigger than Skewes - and has a lot more than a googolplex digits. The last ten are ...2464195387.

Graham's number - Wikipedia, the free encyclopedia

[astropete]

well any of those numbers are easily beat, just add a one.

[acey]

Yeah we're talking about the biggest finite integer that's got a specific name.

Surprised we haven't got onto transfinite cardinals yet - aleph nought, aleph one etc. Programme was apparently about infinity after all.

[Tycho Brahe]

Found this thread and watched it. Cool programe, but there are some gaps in their logic, like they state light travels at ~300,000m/s, but it doesnt. It only appears to travel at 300,000m/s if we measure it here on earth... yet if we are talking about light from the sun, if I built a rocket and flew toward the sun at 90% of the speed of light and I measured the speed of the light coming from the sun I would find it would be 300,000m/s... how can that be? Shouldnt I have measured the speed of light as 300,000m/s minus the speed I am travelling toward the light source? If I was on the rocket I would predict the speed of light on earth to be nearly 600,000m/s!!!

But its not? Why is that? Thats because as we approach the speed of light time slows down, once you reach the speed of light time has stopped! Speed is distance divided by time. If time has effectively stopped, the concept of speed has no meaning... Hence the speed of light is actually the upper physical limit of speed, the point at which speed is so great it ceases to have any meaning, it effectively destroys itself! Which is interesting for us, cause the light you see coming from the stars has not taken many millions of years to arrive here. It only appears to have taken time from our perpective here on earth. From the photons point of view it has arrived here at earth instantaniously! Not a single second has passed since the moment it was created in the plasma of that distant star...

If time has limits it is almost inevitable that space have limits too, after all they are intimately linked as space-time... the four dimensions...