1

The Environment / What can we do at home to stop habitat destruction?

« on: 25/03/2019 12:35:56 »

Jenny wants to take some steps to help the environment:

What can we do at home to stop habitat destruction?

What ideas do you have? Hope it will encourage others too!

2

Physiology & Medicine / How does the body tell friendly good bacteria from unfriendly bad bacteria?

« on: 25/03/2019 12:33:52 »

Paul's been in touch to ask:

How does the body know which bacteria friendly and unfriendly? And, is there a certain amount of bad bacteria or viruses that are good for the body to experience to build up a tolerance to, e.g, if someone sneezes near you do you either get the illness or not, or can a little bit of exposure be a good thing?

Can you help?

3

Technology / Does a satellite's movement through Earth's magnetosphere generate electricity?

« on: 25/03/2019 11:31:04 »

Mark has a space tech question:

Since satellites are generally made from conductive materials, does their movement through Earth's magnetosphere generate electricity? Could this be used to power them freely and safely. It may require an armature wound with copper wire to make a useful current but it's worth a try.

What do you think, any possibilities here?

4

Physics, Astronomy & Cosmology / What is the structure or density of dark matter?

« on: 25/03/2019 11:26:34 »

Peter is curious to know:

Has research been able to determine the structure or density of dark matter and does it interact with normal matter?

If so, it would seem collision would be frequent.The existence of dark matter detected by the effect its mass has on other objects…mainly galaxies if I understand the research correctly. Given that scientists estimate something like 75-85% of all matter is dark matter, clearly there is a lot of stuff out there.

Any insight you can give to help?

5

Physics, Astronomy & Cosmology / What is the connection between virtual particles and the Higgs Field?

« on: 25/03/2019 11:23:07 »

Shekhina wants to know:

What is the connection between "virtual particles" and the "Higgs Field"

Can you help with an answer?

6

Cells, Microbes & Viruses / How is it possible for DNA to contain instructions for all diverse cells?

« on: 20/03/2019 13:52:21 »

Joe wants to know more about DNA:

How is it possible for four proteins to contain the instructions for a living organism given the diversity of cells (brain, placenta, eyes, producing gastric acid, timing of the release of hormones (how do “they” know it’s time for puberty), etc.

Do you have an answer that might help?

7

Physiology & Medicine / How do pharmaceutical drugs target different areas of the body?

« on: 20/03/2019 13:31:37 »

Mary has been in touch to ask:

How do pharmaceutical drugs target different areas of the body? For example, why do different antibiotics work better for fighting acne and some for fighting pneumonia?

What do you think?

8

Physics, Astronomy & Cosmology / How are space capsules designed to be so thin?

« on: 20/03/2019 12:10:48 »

Gary has been watching space videos online and wants to know:

How are space capsules designed to be so thin?

With some space capsules being no more then a tin can or foil thickness in places, how do they hold their shape structurally given differences in pressure inside and outside the capsule?

And how is this able to shield the crew in the capsules from the cosmic rays (van Allan belts and charged partials from the sun) with no lead shielding of at least 7 inches in thickness?

What's going on, do you know how this works?

9

Cells, Microbes & Viruses / Which bacteria makes refrigerators smell when they are turned off?

« on: 19/03/2019 11:20:24 »

Dennis has been catching a whiff of something that he needs your help identifying:

Is there a specific bacteria responsible for the odor produced by a refrigerator when it is turned off?

Any thoughts that might help?

10

Physiology & Medicine / Why is it hard to breathe in a fast-moving car with the window open?

« on: 19/03/2019 10:59:41 »

Katlego has been in touch to ask:

Why do we struggle with breathing when we are in a fast moving car while the window is open?

What do you think?

11

Physics, Astronomy & Cosmology / Why is caesium-137 not more radioactive than plutonium?

« on: 19/03/2019 10:54:40 »

Johnny has asked:

I would think Caesium-137 (with a 30-year half-life) would be about 1,000 times more radioactive than Plutonium. What am I missing?

My understanding of the concept of "half-life" is that it is the time that, statistically, half of the atoms of a radioactive substance will decay (of course they may or may not decay into other also-radioactive elements).

So when I hear "the plutonium in nuclear waste has a half life of 24,000 years" it seems like that means "this stuff decays very, very slowly". Since the number of atoms decaying is small over any given time-span (that's why it takes so long for half of them to decay) doesn't that mean that the amount of radiation being emitted is commensurately small?

Have you got any suggestions?

12

Geology, Palaeontology & Archaeology / How long can sand roses last?

« on: 19/03/2019 10:46:08 »

Gaelle has been adventuring and sent us this question:

We went out in the desert to look for sand roses and I don't know much about them. We found a fair few, but some of them are crumbling...do they last? How long? How can I keep them intact?

I seem to have read that they are made from Gypsum or Baryte and that the gypsum ones tend to be more fragile.

Do you know anything about them?

13

Chemistry / Why would a rose turn water containing paracetamol (acetaminophen) black?

« on: 18/03/2019 12:05:41 »

Kim, a curious teacher wants to know:

During a science experiment, my student dissolved acetaminophen (also known as paracetamol) in water then put a rose in it to investigate the effect it had on the flower. The water turned black, why would this happen?

What's going on to cause this?

14

Plant Sciences, Zoology & Evolution / Is fruit being bred sweeter?

« on: 18/03/2019 10:09:16 »

Asa heard our recent QnA show which discussed sugar in fruit vs. cake, and wonders:

1. Is fruit being bred to be sweeter, and if so, at the cost of other nutrients? 
2. Is climate change, a hotter growing season, increasing the amount of sugar in fruit, again at the expense of other factors?

This week the ABC had a story about wine grapes being sweeter, due to the hotter summer, and less acidic.

What do you think?

15

Physiology & Medicine / How many times a day should we eat?

« on: 18/03/2019 09:55:56 »

Alex is feeling peckish and wants to know:

What does science have to say about how many times a day we should eat?

I've read how ancient Romans ate most of their food at midday, while the food timing of our ancient hunter-gatherer ancestors was probably easy constant access to food at some times, that was broken up by long fasting and belly-popping feasts. Is there some real science on the topic?

What do you know about the subject and can you help?

16

Physiology & Medicine / Can we breathe through our skin?

« on: 11/03/2019 13:49:00 »

Doha has been in touch to ask:

Can we breathe through our skin, or rather diffuse O₂?

Do you know?

17

General Science / Can there be gain of enthalpy by freezing water?

« on: 06/03/2019 15:11:56 »

Hariharan asks:

Can there be gain of enthalpy by freezing water below 0 degree Celsius? If so is the gain of enthalpy by the system or surroundings?

I read that 'thermodynamics teaches that the loss of entropy by freezing the salt solution can be overcome at temperatures below 0 degree Celsius because the gain in enthalpy by freezing water rises when temperature goes down.'

Can you provide any insight?