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Author Topic: Question of the Week - Old Version  (Read 178908 times)

Offline Soul Surfer

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Re: Question of the Week - Old Version
« Reply #275 on: 21/12/2005 10:50:58 »
OK I've left this to sit for 24 hours.  Heavy water is duterium oxide the combination of oxygen with the other stable isotope of Hydrogen duterium which has a neucleus of a single protn and a single neutron  it exists in water to a tiny proprtion and can be sperated by fractional distillation or electroysis.

Its main use is as a moderator in nuclear fission reactors using U235 because it is quite good slowing down the neutrons produced in the fission fron high speeds to "thermal" neutrons (thus extracting the energy of the reaction)the fission chain reaction in U235 will operate with thermal neutrons.  Using a moderator also renders the reaction more controllable by slowing the rates at which things can run away allowing it to be controlled with mechanical devices.

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Offline Bass

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Re: Question of the Week - Old Version
« Reply #276 on: 02/01/2006 22:19:03 »
I have this dim memory, eons ago, that ducks can't float on heavy water??
Any truth to this, or just another myth?

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Offline DoctorBeaver

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Re: Question of the Week - Old Version
« Reply #277 on: 02/01/2006 22:31:26 »
quote:
I have this dim memory, eons ago, that ducks can't float on heavy water??
Any truth to this, or just another myth?


That's because they're witches (Monty Python fans may understand that)
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Offline neilep

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Re: Question of the Week - Old Version
« Reply #278 on: 02/01/2006 23:09:57 »
I wonder of we should change the name of this thread from Question Of The Week to Question Of The Whenever !!;)

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Offline DoctorBeaver

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Re: Question of the Week - Old Version
« Reply #279 on: 02/01/2006 23:19:30 »
Questions from the stone-age:D
 

Offline chris

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Re: Question of the Week - Old Version
« Reply #280 on: 09/01/2006 11:19:28 »
Give me a break you lot.

My new year resolution is to ensure that we have a high quality QOTW each week from henceforth.

We'll start from today and I'll post the question shortly.

Chris

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Offline DoctorBeaver

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Re: Question of the Week - Old Version
« Reply #281 on: 09/01/2006 16:48:45 »
*looks at watch* 5 and a half hours later... zzzzzzzzzzz
 

Offline neilep

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Re: Question of the Week - Old Version
« Reply #282 on: 09/01/2006 18:59:42 »
...hey !!..this a good idea...question Of the Week eh ?...it might actually catch on !

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Offline DoctorBeaver

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Re: Question of the Week - Old Version
« Reply #283 on: 09/01/2006 22:47:03 »
Make that 11 and a half
« Last Edit: 09/01/2006 23:31:48 by DoctorBeaver »
 

Offline ukmicky

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Re: Question of the Week - Old Version
« Reply #284 on: 09/01/2006 23:06:46 »
Give him a chance he's a doctor, and if he's anything like mine he's busy congratulating his patients on catching the flu and them telling them to go away and to let it run its course.

so you then go away and get a chest infection and when you go back the doctor say's arrhh you've now got a chest infection, now go away and let it run its course.

I can do that, maybe i should be a doctor

Sorry chris i know your a good doctor really:)

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« Last Edit: 09/01/2006 23:12:37 by ukmicky »
 

Offline ukmicky

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Re: Question of the Week - Old Version
« Reply #285 on: 10/01/2006 01:16:38 »
Question

Why do we never get to see the dark side of the moon



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« Last Edit: 10/01/2006 01:18:58 by ukmicky »
 

Offline neilep

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Re: Question of the Week - Old Version
« Reply #286 on: 10/01/2006 01:40:38 »
Gosh !! i'm dumbfounded...I actually know the answer to this but seeing as Michael only asked it less than half an hour ago I'll leave it for some of the non vampires to respond to.

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Offline DoctorBeaver

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Re: Question of the Week - Old Version
« Reply #287 on: 10/01/2006 02:11:26 »
I think you've asked either a wrong question or a trick 1.
I suspect the answer you want is that as the moon's period of rotation is the same as the time it takes to orbit the Earth, the same side is always facing us.
However, even if the 2 periods were different so that we could actually see the moon rotating on its axis, we would still never see "the dark side" as we could only ever see whichever part of the moon was facing the Earth.
In any case, at new moon even the side that is facing us is dark & we can still see that with light amplifying equipment.

Pedants rule! [:p]
 

Offline ukmicky

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Re: Question of the Week - Old Version
« Reply #288 on: 10/01/2006 02:38:23 »
Damn your good.



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« Last Edit: 10/01/2006 03:40:06 by ukmicky »
 

Offline DoctorBeaver

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Re: Question of the Week - Old Version
« Reply #289 on: 10/01/2006 02:58:12 »
quote:
Damn your good.


That's what she said last night :D
But she was talking about my cooking :(
 

Offline ukmicky

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Re: Question of the Week - Old Version
« Reply #290 on: 10/01/2006 03:40:30 »
I  think its weird how the one species of life on earth since its creation which is able to appreciate an eclipse of the sun happens to be around at the best time to view it. if we were around much earlier in the history of the earth the moon would be closer and cover too much up and much later and the moon will be further away from the earth and not cover up enough.
At present time the moon  400 x nearer than the Sun with a radius which is 400 x smaller than the sun. WEIRD
At present time the moon also rotates once  every time it orbits the earth , so we always get the same view THAT'S ALSO WEIRD


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Offline chris

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Re: Question of the Week - Old Version
« Reply #291 on: 10/01/2006 09:53:52 »
I've seen Dark Side of the Moon. In fact I'm looking at it now, alongside "Momentary Lapse of Reason" and "The Final Cut".

Sorry about the lack of a question last night. My computer actually decided to die at 4.30. Nice.

Anyway, I think ukmicky's question about the dark side of the moon is actually excellent, so let's kick off with that, and I'll save my question for next week.

Chris

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Offline DoctorBeaver

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Re: Question of the Week - Old Version
« Reply #292 on: 11/01/2006 01:37:11 »
What a cop out! [:o)]
 

Offline chris

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Re: Question of the Week - Old Version
« Reply #293 on: 15/01/2006 14:46:46 »
Here's this week's QOTW (and this time there will be a weekly turnover of questions):

"WHY DO WE SEE OUR BREATH ON COLD DAYS ?"

Have a go, below...

Chris

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Offline DoctorBeaver

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Re: Question of the Week - Old Version
« Reply #294 on: 15/01/2006 15:45:02 »
That's easy. (but don't ask Blunkett) [:o)]
« Last Edit: 15/01/2006 15:45:46 by DoctorBeaver »
 

Offline chris

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Re: Question of the Week - Old Version
« Reply #295 on: 15/01/2006 21:41:57 »
Come on then, let's see the answer...

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Offline DoctorBeaver

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Re: Question of the Week - Old Version
« Reply #296 on: 16/01/2006 20:58:21 »
Temperature difference blah blah condensation blah [:p]
 

Offline DoctorBeaver

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Re: Question of the Week - Old Version
« Reply #297 on: 16/01/2006 21:00:39 »
Actually, to answer your question, we can see it because it's visible. The question should really have been "Why is it visible?"
 

Offline ukmicky

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Re: Question of the Week - Old Version
« Reply #298 on: 17/01/2006 01:58:16 »
quote:
The question should really have been "Why is it visible?"


Because we have eyes

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Offline DoctorBeaver

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Re: Question of the Week - Old Version
« Reply #299 on: 17/01/2006 04:13:15 »
No, Michael. We can see it because it's visible and we have eyes. Moles can't see it, but it must be visible as we can percieve it. Therefore, we can see it as it's visible to us.
But Chris, I believe, is after the process that makes it visible; which is a different question.

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Re: Question of the Week - Old Version
« Reply #299 on: 17/01/2006 04:13:15 »

 

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