Lois Pasteur demonstrated that life comes from life. That is rotten meat doesn't spontaneously produce flies. And Darwin postulates that all life evolved from earlier forms of life. The paradox here is, as I see it, that when we extrapolate back to the creation of the planet we're told that it was a sterile hot and hostile place. The leading theory seems to be that the hotch potch of chemicals in the primitive earth somehow came together to form life. My query is just how "simple" does a molecule have to be to be on the border between life and non life?

One criticism often levelled at soccer is that the game can be unexciting as not many goals are scored in most matches. What would be the likelihood of goals if the rules were changed to allow two footballs to be in play at the same time?

Tony Holkham, Petersfield, Hampshire, UK

Another week, and another rash of great questions on the Last Word site. We started on a fishy note, with baloo asking why it is that fish gills only work in water. Find out why here: http://bit.ly/b4w8n5

canivet290468's question caught my eye, as my morning train ride in to the New Scientist offices has been shrouded in mist most of the week. If you could assemble a temporary building in seconds in thick fog, would you still see the fog inside?? http://bit.ly/aCW5UE

Fitness fanatics among you might be intrigued by mal14's poser: when you burn fat off, where does it actually go? Well, where does it go? Down the toilet or somewhere else? http://bit.ly/92qVQh?

The penultimate question is particularly poignant for me, as I sit typing before I head out of the office for lunch. draki asked why some people get irritable when they're hungry? http://bit.ly/dwS8u9? I'll do my best to behave calmly, dear reader, but I am in need of food.

So let's quickly finish up. Here's a final question to get you thinking over the weekend. What is technology doing to the evolution of the human species? Have your say here: http://bit.ly/9N42z4

Have a great weekend, and make sure to eat enough to stave off bad moods.

Cheerio,

Jamie

When the classic simple demonstration is done with a bell jar inverted over a bath of water, with a floating lighted candle inside, as the Oxygen is used up, the water rises up the bell jar about one fifth or 20 - 21% of the way up, until the candle goes out, showing that there is approx 21% Oxygen in normal air.

However, 21% volume of Oxygen surely cannot equate to 0% volume of Carbon dioxide, so where did the carbon-dioxide go? Surely, it must have some volume?

The Challenger Deep in the Mariana Trench is the deepest point in Earth's oceans. The bottom there is 10,924 meters (35,840 feet) below sea level and therefor at a pressure of nearly 2000bar.  Even if the bomb detonation was higher pressure than would a steam bubble be generated or would it remain as superheated water and just dissipate?  If a steam bubble was generated would the shear mass of water surrounding the detonation point condense it?

Are you sitting comfortably? I am, I'm sitting with my legs crossed. Of the four people whose legs I can see from my vantage point in the New Scientist offices, three others are sitting the same way. So why is it that we instinctively sit with our legs crossed? http://bit.ly/9aJ7HK?

There have been some planetary ponderings this week on The Last Word. hugolabs wondered if we can determine the thermodynamic state of a planet. What do you think – can we calculate whether a planet emits more heat than it absorbs? Have your say here http://bit.ly/bU2hHM and check out what our Facebook group thought here http://on.fb.me/cTxX9l

Similarly, alanrbarrowXqzBk wondered if the mass of the Earth varies. With meteorites crashing into the planet, and the dynamic between gaseous, liquid and solid material, is the mass of the Earth increasing? http://bit.ly/baDmSn

If all that space-based fun gets you hot under the collar, maybe you'll be interested in Marmaduke's question. He asked The Last Word, given that humans evolved to live in hot environments, why is it that we all prefer air conditioning to being stuck in the heat? http://bit.ly/9fAQRl

Finally, here's something for the weekend: it might come in handy if you have occasion to prepare a Sunday roast. Why is it that when frozen peas are put into a pan of water some float and some sink? http://bit.ly/c9VkBo

That's all from me for this week! Have a great weekend.

Peas!

Kat

Letters and comments editor, New Scientist

an infinite maze .. a maze that you can't escape , that doesn't mean your gonna run into a "road block" .. just a maze that has a starting point but no finishing point ..  

This "paradox" doesn't work!

If all the hotel rooms are full, you can not simply move a guest to another room.

In the paradox, does it imply that EVERY guest is changing room at the same time or one by one.

If the new guest moves into room 1 while guest 1 is moving into room 2, etc, there will always be 1 guest on the move indefinitely.

So to accommodate every new guest, the same amount of guest would have to be on the move and technically without a room while moving.

If it implies that ALL the guest is moving at the same time, this is not possible because there is no vacant room to move to since EVERY room is occupied already.

So, either you can accommodate a new guest by forcing a guest on the move or you can not accommodate any new guests because ALL the rooms are already occupied.