Can dogs smell cancer?

Can dogs smell cancer?

Yes, they can!

To find out more: visit Cancer is Weird, my blog on all things cancer.

The Entropy Conundrum.

There's a question I've heard on more than one occasion.

"Doesn't evolution or life itself violate the second law of thermodynamics?"

The second law of thermodynamics states that the entropy of a closed system must always increase. And entropy is a measure of the disorderliness of a system.

So, I've been reading Nick Lane's book 'The Vital Question', and I've come across a few interesting ideas.

Apparently, there's a lot of difference between things that "seem disordered" and things that "are disordered".

An example is:

While an irregular mixture of oil and water might seem less orderly than the lipid bi-membrane of a cell, it is not so,

Lane argues that this conundrum arises because we tend to ignore the subtle balance between a system and its environment.

A lipid bi-membrane is a stable, low energy configuration of molecules, and in achieving that configuration, the molecules lose heat. The overall entropy increases.

I suppose the same argument might be applied to explain the evolution of some, if not all molecular machinery in the early cell prototypes.

While the example I've chosen here, from Lane's book, is quite simple, I would love to know about the changes in entropy when considering a more complex organic molecule,


Any input regarding the same, can be shared in the comments section.

P.S. I'll be sharing my thoughts on the book, as and when I read it. I would highly recommend reading "The Vital Question", as it tries to answer some of the most difficult, yet fundamental questions in biology.

Nanoparticles in motion?

So, we've formally defined nanoparticles as any particle of the size range 1-100 nm (where 1 nm = 0.000000001 m). And this is the scale at which nanotechnology operates.However, I was thinking about nanomachines in nature. Nanorobots that have come alive through the process of evolution.

I'm talking about viruses. Yes, those pesky little things that make you sick. Viruses pose a problem, however. We don't know whether to classify them as alive or dead. Before we make an attempt to do that, we need to understand what the term "life" means and define what a living thing is.

The Nobel laureate physicist Erwin Schrodinger defined life this way: "Living things avoid decay into disorder and equilibrium". And that's a pretty good definition. Also, it means that viruses are very much alive. Viruses replicate, have DNA/RNA as genetic information, a boundary of proteins that separates it from the environment and are subject to evolution.

I like to think of viruses as nanorobots as plenty of viruses fit in the formal definition of a nanoparticle. The smallest dsDNA viruses are the hepadnaviruses such as Hepatitis B, at 42 nm; parvoviruses have smaller capsids, at 18-26 nm. As a whole the viral family geminiviridae is only about 30 nm in length. However, the two capsids making up the virus are fused, divided the capsids would be 15 nm. (Source: click here)

So, while we began thinking about nanoparticles in the early 1960s, nature was already engineering its own nanorobots for millions (perhaps billions) of years.

So, are we alone in the universe? (Fermi's Paradox)

Given that the universe is 93,000,000,000 light years, and each light year is equal to 9,461,000,000,000 kms, we've got a lot of space to begin with. In that space, there exist billions of galaxies, each with billions of stars having trillions of planets. 

Also, the universe started out somewhere around 14,000,000,000 years ago, so we've got a lot of time, too. However, I think, considering our universe's chaotic past, a major chunk of time was not a good time for life to evolve.

So, any life-form in the universe must have begun roughly 4,000,000,000-6,000,000,000 years ago as Earth is considered to be among the oldest habitable planets.

Just pondering over these numbers will convince you that life exists elsewhere. And that's a good enough assumption. Or is it?

For more information, click here. Or watch an amazing video by Kurzgesagt on YouTube by clicking here.