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You are here > Science & Nature message boards > Deleted > Universe puzzles

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Universe puzzles

Messages  121 - 137 of 137

 
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Message 121 - posted by Nic Davies (U13674697) , Nov 4, 2009

Hi Birder_Dave. Just got back in. Yep, good one. My guess should of course referred to the North Pole not the South, but at least I got the whole infinite number bit!

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Message 122 - posted by Birder_Dave (U14198725) , Nov 4, 2009

Okay, if you are in ZERO gravity conditions, which way is UP

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Surely this is not a serious question.

Here is one I often think about, if you were driving a space ship at the speed of light, and you then turned on the headlights, would they work? (and before anyone corrects me, I know you can't travel at the speed of light)

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Message 123 - posted by les-do-it (U14186179) , Nov 4, 2009

Gravity determines the convention we normally accept as UP or DOWN. We can all associate with the little accident with our toast----did it land butterside up or down. We have established a difference in attitude.

In zero gravity conditions the convention is compromised. So as the participant and observer. Up is determined to be any which way you want it to be.

Therefore, during a space walk, you could be looking Up at earth even though it is accepted as being below you.

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Message 124 - posted by les-do-it (U14186179) , Nov 4, 2009

I'll get back to you about the speed of light. Dinner awaits

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Message 125 - posted by Nic Davies (U13674697) , Nov 4, 2009

Mmmm, I think within your own planetary system, it is possible to consider the 'horizontal' (yeh, I know!) plane of the system as your point of reference. Whether this means astronauts from the northern and southern hemispheres out together for a space walk would think 'up' and 'down' respectively, is a point to ponder.

It's rather like that famous photograph of 'Earth rise' from the Apollo missions. When you study the photo, it is of course (to my eyes) 90 degrees out of kilter as it shows the planetary plane as being 'vertical'.

It's all relative, but relative to what?

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Message 126 - posted by Birder_Dave (U14198725) , Nov 4, 2009

I think that in space there is only "out" I think that the fact that you may have to tilt your head in the way we call "up" to see something does not automatically make it so.

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Message 127 - posted by diapensia (U13926430) , Nov 4, 2009

Scientists claim that the universe is so vast that they cannot see the end of it.
It is an experiment in a glass dome on a laboratory bench. It was only switched on 30 minutes ago and the scientist has gone for his lunch and left it!

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Message 128 - posted by Birder_Dave (U14198725) , Nov 4, 2009

Here is one for you to ponder. When the rain clouds are spread out and the rays of the Sun shine through them they make a kind of A shape tracing from the ground through the gaps in the clouds and to the Sun.
Now, if you were to continue the angle of those rays upward they would meet at a point only a few thousand feet up. The Sun is around 93 million miles away, so how do the rays come down at those angles?

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Message 129 - posted by Nic Davies (U13674697) , Nov 4, 2009

Those rays only APPEAR to come down at that angle. If you think about it, if you stood directly under one of those rays, you'd be staring straight at the sun and so on for all of them. They all originate at the sun, it can be no other way. Light can be bent of course but hardly at all at that distance or by our feeble atmosphere.

It's the same reason that meteor showers appear to eminate from a single point, when in fact their paths are mostly parallel.

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Message 130 - posted by diapensia (U13926430) , Nov 4, 2009

Why are clouds flat at the bottom?
Also I have a photo of a normal rainbow with an inverted rainbow above it and meeting at the apex.

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Message 131 - posted by Birder_Dave (U14198725) , Nov 4, 2009

Well actually I was so puzzled by this that I wrote to the head of physics at Sheffield University. He actually praised me for noticing it. He said it was caused by the (something I can't remember) effect which happens when the suns rays hit the atmosphere. He said it was just like when you look at a pearl light bulb and the light seems to be coming from the whole of the outer glass when in fact it is only coming from the filament in the middle.

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Message 132 - posted by Nic Davies (U13674697) , Nov 4, 2009

Hi Birder_Dave. I'm confused as that doesn't seem to make any sense for the simple fact that as I said you'd be looking straight at the sun by looking up any of the beams you're talking about. Or am I missing something? I know the effect you're talking about but I have to assume it's simply an optical illusion (like meteor showers and the non-existent point from which they all appear to originate, that has a name but I can't remember what it is!).

If the bulb analogy is accurate, then surely the light source would actually be wider (not a point, ie filament) and hence would give a narrower look to the beams (ie the angle would be lessened not increased).

Hey, it's late, and I have no real idea what I'm talking about. I too like mind-bendery stuff like this, but it's probably only a matter of time before someone spots this thread and complains it's not about wildlife!

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Message 133 - posted by diapensia (U13926430) , Nov 4, 2009

Time flies like an arrow. Fruit flies like a banana.

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Message 134 - posted by Nic Davies (U13674697) , Nov 4, 2009

Homer exclaims "It's true, it's so true!".

Nice one diapensia, my partner's kids will love that one!

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Message 135 - posted by Mike (U12205184) , Nov 4, 2009

Oh Yeah!!!!! duh! stupid me! thanks @pen-y-bont_mike How would that work on the equator though? i'm confuzzled!

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Well I was on the right lines picking all points on a line of latitude. I just chose the wrong one, the equator. doh

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Message 136 - posted by Birder_Dave (U14198725) , Nov 5, 2009

Diapensia, I have a son just like you. He too thinks the things he says are funny.

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Message 137 - posted by diapensia (U13926430) , Nov 5, 2009

Where does he get it from?

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Messages  121 - 137 of 137

 



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