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Technology / Could you use two rail guns to collide two plutonium cores for nuclear fission?

« on: 04/11/2019 12:18:16 »

Zubin asks:

Could you use two rail guns to collide two plutonium cores for nuclear fission?

What do you think?

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Plant Sciences, Zoology & Evolution / Who is better at climbing: spiders or geckos??

« on: 21/06/2019 10:11:30 »

Jay was wondering:

I noticed that in your article titled: "Can we mix human and spider DNA?" that we would be better off taking inspiration from geckos who use Velcro-like pads at the base of their feet. However, spiders work on a similar principle except my understanding is that their way of doing things is better simply due to the fact that they use hair follicles that are rigid enough to allow them to stick to the smoothest surfaces as at a molecular level everything is rough. So the question is which is more efficient having a higher surface area that consists of tiny rigid hairs or a type of Velcro. But in the grand scheme surely both work in similar ways?

What do you think?

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Physics, Astronomy & Cosmology / Would a bullet travel further in hot air or cold?

« on: 21/06/2019 09:55:05 »

Paloma and her son are having a debate:

My son asked: "how far can a bullet travel until it stops?"
We then discussed if it would be farther in hot or cold air.
I said cold, he said hot.

Who do you think is right and why?

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Plant Sciences, Zoology & Evolution / Are there more species of mushrooms or fish?

« on: 21/06/2019 09:40:37 »

Kitty asks:

Are there more species of mushrooms or fish on earth?

What do you think?

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Physiology & Medicine / Why do girls freeze in the evening?

« on: 18/06/2019 11:58:15 »

Mike asked:

Why do my wife and daughter feel hot in the mornings whereas our son and myself freeze in the morning? Why do the girls freeze in the evening ( their hands and feet are ICED ) when we boys feel really warm and cosy?

Can you help?

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Cells, Microbes & Viruses / How does a cell know it is a muscle cell vs a skin cell?

« on: 13/06/2019 16:02:45 »

Jon asked:

I heard about using stem cells to cure heart disease, which got me to wonder exactly how a cell knows what kind of cell it is.  That is, the genome is available to create a variety of proteins, and some pattern of enabling occurs for each type of cell, but where is the identity of the cell stored?  How does a cell know it is a muscle cell vs a skin cell?

Can you help?