261

Just Chat! / Re: Forum politics 101

« on: 24/07/2012 04:32:40 »

   

Uhhh...
So, if a person asks "how fast"...  I should just answer "faster than a Chetah on steroids".
or "how far"...  "further than I can run in a day".

Point taken. d=^t/_w where d is my desire to know more, t is the time I have to spare, and w is the amount of work I have to do to research a topic properly. The last value always seems so high !

   

Nobody is here to conduct experiments for you though, unless it turns out to be very interesting.

Damn! another assumption of mine dashed! I hate being constantly reminded that despite existing in an homogenous and isotropic universe, I am not, in fact, the centre of it!

262

Just Chat! / Re: Punning is hard(ly) work! Groaning aloud here?

« on: 24/07/2012 04:03:35 »

I already felt funny about including Wonder Woman in a Marvel dominated post - I thought that would be controversial enough. I also thought that the friendly combat managed to create a throb inside my head!

I should be a cryptic crossword writer! 

263

Just Chat! / Forum politics 101

« on: 24/07/2012 03:47:51 »

As a newbie, not only to the Naked Scientist forum, but to forum's in general, I'm curious to know more about the social structure. I can see there is a measure of how many posts people have done and there seems to be a few hardcore posters that kind of over see everything. There also seems to be some sort of gold square rating. Is this based on number of posts?

Also, what's a moderator? Are these just trusted members or are they members of the Naked Scientists production team?

Also (again), does the production team trawl the forums for inclusions in the show? Or is this a separate entity for the more scientifically enabled. I make this last comment because although I have enjoyed receiving answers for most of my posts, there seems to be a lot of topics that have formulas and a fairly high level of prior knowledge is required. It may just be that the particular topic requires this level of maths but I guess part of why I love the Naked Scientists so much is the accessibility of the language used to answer complex scientific questions.

Or maybe I should just go and do that Physics degree I always dreamt about...

264

Just Chat! / Re: Punning is hard(ly) work! Groaning aloud here?

« on: 24/07/2012 02:04:16 »

I can hardly compete with the marvel that is demographic. Novel as it is, it would take six men to weather the storm, and while i'd find going AWOL veri necessary at times, the magnet of scientific discovery gives me resolve stronger than iron! Man was not born to crawl like the spider! Man was made to wonder! Woman too.

265

Just Chat! / Re: Punning is hard(ly) work! Groaning aloud here?

« on: 23/07/2012 07:06:27 »

so this is how you neilp level members get so many posts! A mundane way to spend time on a science forum - there must be better! As a nubi, I surely can't hope to compete with other members, or SOS! I risk the wrath of the gods!

266

General Science / Are primary colours a matter of opinion?

« on: 23/07/2012 05:26:56 »

I'm not sure where to post so general science seemed safest.

Is there anything fundamental about primary colours and their properties in combining to make up the entire spectrum of colours we see? Or is it an artefact of the types of receptors (cones or rods? I can never remember) we have in our retinas?

Or, in other terms, are primary colours purely an arbitrary reference based on our ocular physiology, or would their qualities exist without our retinas?

I'm reminded that the metric system makes a lot of sense and seems intuitively natural, but holds no connection to mathematic fundamentals. It only appears natural to us because we decided that a base 10 counting system was right. The metric system would be ridiculous if we had a base 7 counting system!

Regards,
Luke

267

Physics, Astronomy & Cosmology / Re: How do photons lose energy in red shift?

« on: 23/07/2012 02:56:34 »

I'm not one for formulas and like Magnus, have found the discussion difficult to follow, but in Geezer's example, it seems to me that we would be able to measure the same amount of energy as if it were stationary, it would just take more time to do it.

If the laser was pulsed for say, 10 seconds (according to a timer attached to the laser), and we measure the energy from the photons, we get a reference. Then we shoot it into space as per the example, wouldn't we measure the same amount of energy if we measured the entire pulse - which would take longer than 10 seconds? Similarly, if it were blue shifted towards us, it would presumably be a higher energy state but the pulse wouldn't last as long?

I hope you can follow my point.

Luke.

268

Plant Sciences, Zoology & Evolution / Re: Did sabre-toothed tigers shape human evolution?

« on: 19/07/2012 19:55:51 »

Yes, I'm afraid I must apologise, though I'm not sure where. I re-posted a few emails i'd sent and not heard back about, only to find out that they had gone through to the forum after all
I will continue to post through my forum id only from here on in. Sorry doc!

269

General Science / Re: Why does my voice sound different in my head?

« on: 19/07/2012 07:38:43 »

When we speak, part of the sound we hear comes from the sound of our voices reaching our ears, but part of it is also internal resonances through our skull, which can stimulate the cochlea directly, and this changes the frequency response slightly.

There is also some resonance in our ear canal. You can get an idea of this if you block your ears and speak, although the effect is exaggerated by the blocking of the ear canal.

This becomes a problem when we fit hearing aids because if someone has good low-frequency hearing, blocking their ear canal with a mould makes their own voice intolerable to them. It's called the occlusion effect. http://en.wikipedia.org/wiki/Occlusion_effect

That's why I'm always disappointed to find out that my voice isn't manly and full of dulcet tones, but rather whiny and nasally and horrible!

270

Physics, Astronomy & Cosmology / Could Jupiter be detected from a distant planet?

« on: 19/07/2012 06:48:41 »

If a civilisation existed near an extra-solar planet that we have been able to detect, would they be able to detect Jupiter using the same techniques?

271

The Environment / Re: Why do clouds look the same from both sides?

« on: 19/07/2012 05:23:43 »

Love that picture!

I should clarify what I mean by "the same". Obviously clouds are different shapes from different angles, but I would have thought that there would be some difference in colour/ opacity etc. from an observation with a light source behind the cloud, and one with a light source in front.

Whilst their shape may vary, clouds of a similar type will have the same (for example) "white fluffiness" whether the light is behind or in front.

272

Chemistry / Re: Has absolute zero ever been proved?

« on: 19/07/2012 04:25:11 »

So it's more like an asymptotal target? - We can get ever closer but never quite there?

273

Plant Sciences, Zoology & Evolution / Which came first, life or DNA?

« on: 19/07/2012 01:07:18 »

I'm just wondering how DNA started. As far as I know, it is an enormous molecule that hides in our cells and tells them what to do. And there are genes and chromosomes (I don't pretend to know how it all goes together!).
My question is: Is DNA the same length for all living things? Is variety dictated only by the GATC code that makes up the molecule, or is it also dictated by how long it is?
Stemming from that point, how did it start? It seems improbable that the first life just happened by amino acids combining into the complex DNA molecules we have today (again, I welcome corrections), so is there any evidence for an evolution of DNA and does it stand to reason that DNA itself has evolved out of life?

274

The Environment / Why do clouds look the same from both sides?

« on: 19/07/2012 00:02:34 »

I'm afraid this is not something I have dilligently documented, but it seems to me that clouds look the same whether the sun is shining on them, or from behind them.
In an aeroplane above the clouds, we are viewing them from the same side as the sun, yet they look the same if we are underneath them, viewing them from the opposite side of the sun.
Is there something in this? Or is it just my flawed, human brain ignoring the inconvenient data to make a convenient pattern?

275

Physics, Astronomy & Cosmology / can two objects travel away from eachother at more than the speed of light?

« on: 17/07/2012 01:04:33 »

I apologise if this has already been addressed on the forum, but here goes...

If a ship accelerates to say, two thirds the speed of light, while another ship accelerates to the same speed from the opposite direction, are they actually moving towards each other at more than the speed of light? What would a person on each ship see as they approached and as they passed (ignoring the obvious limitations of human sight)? How is this different from a ship moving away from the earth at 1.33... times the speed of light?

276

Plant Sciences, Zoology & Evolution / Were early hominids REALLY all that threatened by sabre toothed tigers?

« on: 16/07/2012 10:28:08 »

I’ve often wondered how much of a role the sabre toothed tiger actually played in our evolution. When explaining things like how our adrenal glands developed to strengthen us in fight or flight, to the role that families played in evolution to provide increased protection against predators, the sabre toothed tiger is often trotted out as the main antagonist of early hominids.

Were they really this much of a threat to early humans?

277

Chemistry / Has absolute zero ever been proved?

« on: 16/07/2012 02:16:32 »

I'm wondering whether "absolute zero" is a calculated conclusion, or an observable phenomenon. If it is the latter, how is it observed?

278

Physics, Astronomy & Cosmology / How do we know whether a star has a red or blue spectrum shift ?

« on: 16/07/2012 01:29:47 »

In regards to the red shift and blue shift of stars to measure their movement away or towards us: If the only information we have to recognise distant stars is the light emitted by them, how do we know that the red shift or blue shift isn’t just the colour of the star and not due to movement? How do scientists find the value from which to measure the Doppler shift?

279

Chemistry / Is there a speed of heat?

« on: 16/07/2012 01:26:22 »

When trying out my new stainless steel frypans, I noticed they heat up and cool down much faster than my old ones. Is there a measureable speed at which heat radiates through a material, and what is the quality of the material that would influence such a speed?