1

Plant Sciences, Zoology & Evolution / Re: Can a cat sense when we are ill?

« on: 21/10/2021 10:37:09 »

Hello @Zer0!

Yes, I am a new intern, I started a couple of weeks ago and I'll continue posting some questions from listeners in the coming weeks

Thanks for engaging with them - I'm already learning a lot of new science from this forum! 

2

Chemistry / What happens when you melt gold into glass?

« on: 15/10/2021 12:10:12 »

Marcos wrote to us to ask:

I am curious about the process of melting gold into glass. Why if you mix it with clear glass you get red-cranberry glass, but if you melt it with blue glass, you get saphiret? Also, what is the technique for recreating saphiret? I can't find A SINGLE ARTICLE on the "how", all topics are all about the "what"... Is it mixed up in the crucible? At what point? How does one work with it once created? What are the steps for, say, cabochon/chaton making? How long does it need to be annealed? I have more questions too, about foiling the back of the glass stones too, but I wanted to stick with the basics to start.. thank you!

Can anyone help?

3

Physics, Astronomy & Cosmology / The physics of cross-country skiing

« on: 15/10/2021 11:54:22 »

Christophe wrote to us from Switzerland to ask:

I have started cross country skiing this year, and I am struggling to understand what is going on in the classic style (diagonal stride). I have tried watching many videos, like this one:

All your weight is on only one ski nearly 100% of the time. The skis are cambered, so that when we glide, the grip zone in the middle does not touch the ground. Instructors say you have to push down on your ski so that the grip zone touches the ground when you need to kick (this misleading word is the usual one). But since your weight is already on the weighted ski, how can you weigh even more? I have tried on my scales and it works if I briskly stand on my toes, I become about 15% heavier. But when I watch the footage, I can see this is not what they do in diagonal stride. I have tried to reproduce diagonal stride standing on one foot on my scales and kicking, but there is no clear pattern emerging. So I am a little bit confused about what happens.

What do you think?

4

Technology / Are fly zappers safe?

« on: 13/10/2021 15:37:42 »

Tarkey wrote to us to ask:

I am interested in getting a fly zapper. However, reading on line, it has been described as dangerous. When flies are zapped, they explode and emit a mist which contains nasty stuff, including E Coli. Is that true?

What do you think?

5

Physiology & Medicine / How does the stomach detect poison?

« on: 13/10/2021 15:15:34 »

Robert wrote to us to asks:

My father was a medical orderly in Burma in the 2nd world war. Many procedures they performed then appear to have been forgotten. One was the use of potassium permagnetite for throat infections. Gargling with this chemical can be very effective, but should you accidentally swallow the solution the stomach immediately throws it back out.

How does the stomach detect this poison and not allow it entry?

What do you think?

6

Plant Sciences, Zoology & Evolution / Can a cat sense when we are ill?

« on: 13/10/2021 15:06:18 »

John asks:

Can a cat sense when we are going to die or when we are ill?
How do they do this? Is it through their sense of smell or can they sense things which we cannot?
Why were cats so revered in Egypt in ancient times?

What do you think?

7

The Environment / If the Earth is losing mass, is the atmosphere expanding?

« on: 13/10/2021 14:55:25 »

According to estimates made by Naked Scientist Chris Smith in this article (https://www.bbc.com/news/magazine-16787636), the Earth is losing mass.

Mike wrote to us to ask:

If the Earth overall is losing mass, the effect it has on gravity, however slight, may affect our atmosphere in a much different way than simply allowing hydrogen and helium to escape as a natural consequence. As we convert solid fuels (fossil and other) into heat, two factors occur at a minimum: release of hydrocarbons and infrared heat.  Add to this the loss of water stored in 3 trillion trees lost, and the amount of water vapor / heat being created by combustion is a SUBSTANTIAL NUMBER.

If the Earth is a bubble per se, inside an atmosphere containment, what is the result of increasing gaseous releases  and total heat / vapor produced by all combustion sources? What are the chances that the atmosphere is expanding relative to the stable size of the Earth itself, increasing atmospheric volume to store billions of tons of more water vapor?

What do you think?

8

Technology / Is there a way of disrupting incoming tsunamis?

« on: 07/10/2021 15:31:48 »

Paul asked:

Is there a way to disrupt tsunamis either just before they reach the shoreline or on reaching the shoreline? I was wondering if there was some way of turning the tsunami against itself so it cancels itself out. Could this be done with a series of walls at different angles?

What do you think?

9

Geology, Palaeontology & Archaeology / How can we date coprolite?

« on: 07/10/2021 15:23:31 »

Freddie asked a few questions about coprolite and the intects contained inside it:

If the animal that produced the coprolite is unknown, how can a date be attributed to it? Furthermore, how can a date of 230ma determined for an animal from coprolite? This date is very close to the oldest dinosaur date, if in fact it was a dinosaur. May I also inquire, have the insects changed over time, or are they the same today?
On a different theme, may I ask how the numerous examples of dinosaur 'soft tissue' now found, have survived for tens or even hundreds of millions of years?

What do you think?

10

Physics, Astronomy & Cosmology / How do high-performance optical mirrors work?

« on: 07/10/2021 15:10:57 »

Rajesh wrote to us to ask:

Why do a High Index material and a Low Index material need to be used alternatively in high-performance optical mirrors?

What do you think?

11

Cells, Microbes & Viruses / Does the fittest always survive?

« on: 06/10/2021 14:46:11 »

Tony wrote to us to ask:

Hey guys, I’m trying to find a paper I once read, is about E coli and the survival of the fittest, more specifically is about a experiment that shows that survival of the fittest might not be completely true under some circumstances, he put two version of E coli in a petri dish, one is the basic version, the other is a much more evolved, in theory the evolved one should wipe the basic one right out, but after a while they actually reached a balance where the evolved one have most of the territories but leave the basic one a good area to live.

Have you heard of that paper? What do you think of the results mentioned by Tony?

12

The Environment / Are there better solutions to deal with sewage?

« on: 06/10/2021 14:40:07 »

Jil from New Zealand wrote to us to ask:

One thing that concerns me is the amount spent on infrastructure to deal with sewage. This whole idea of using water to shift sewage around in pipes to treatment plants, seems the wrong way to deal with it, in a world that moves, has earthquakes and floods.  And now the trend is to regard sewage as a resource to extract water and nutrients from.

Would it not make more sense to render sewage harmless as soon as possible (using enzymes, heat, light treatment or whatever? ) and then put that neutralised product back into the local area, rather than transport it to a processing plant?

I know there are some domestic sewage treatment options out there which a minority may be able to afford or develop. I understand sewage in space is dehydrated and brought back to earth. The future has to have something less risky than piped sewage. Effluent overflow is such a major problem in times of disasters. I am sure there are brilliant minds out there with solutions.

What do you think?

13

Plant Sciences, Zoology & Evolution / Is there a biological base to sexual orientation?

« on: 06/10/2021 14:24:59 »

A listener wrote to us to ask:

Hi! There are people who identify as e.g. bisexual, homosexual etc. Is it possible that it is also biologically linked?

What do you think?

14

Physiology & Medicine / Brushing teeth straight after breakfast or not brushing at all?

« on: 06/10/2021 14:18:38 »

Margaret wrote to us to ask:

One of the recent (?) (I often listen to old ones) podcasts was about brushing teeth and said that we should brush AM and PM but it's best not to brush until about an hour after breakfast because of acid increase eating away tooth enamel.  It is often hard to make this work on a morning schedule, so which is worse, brushing right after breakfast or not brushing at all?  In fact we eat dinner really late so this might also apply to brushing soon after dinner... AAARRRGGGHHH!

What do you think?

15

Technology / Why do rockets smell and make a noise when they are nearby?

« on: 06/10/2021 14:12:01 »

Elizabeth wrote to us from Scotland to ask a few questions about rockets:

Why do rockets smell and make a noise when they are nearby? How can rockets/space junks suddenly move if they see a rocket they don't like when they are meant to be a bit of junk/rocket that can't do anything? How can a rocket almost park on top of a house without setting on fire the contents of it? What material is the safest to have on a house roof to block microwaves from rockets?

Can you answer any or all of them?

16

Geology, Palaeontology & Archaeology / To what extent could Homo Sapiens and Neanderthals have children together?

« on: 06/10/2021 14:01:41 »

Alexander from Auckland (New Zealand) wrote to us to ask:

If we accept that Neanderthals and human are different species, interbreeding resulting in fertile offspring should, by definition, be impossible or at the very least extremely rare. How then do you account for the fact that up to 15% of the human genome is considered to be of “Neanderthal origin”?

What do you think?

17

Chemistry / Why don't plastic food containers dry in a dishwasher?

« on: 06/10/2021 13:51:35 »

Ben wrote to us to ask:

Why don't plastic food containers dry in a dishwasher? All porcellain, glass and metal items get properly cleaned and subsequently dried, but the drying part fails consistently with the usual food containers of various brands and age.

What do you think?

18

Physics, Astronomy & Cosmology / Can we ever truly describe space as empty?

« on: 06/10/2021 12:09:13 »

Ron wrote to us to ask:

"Can space ever be described as empty when the electrostatic field of oscillations is always active allowing us to perceive the history of our universe?"

What do you think?