Comments on: Questions Show: Undoing Inflation, Searching for Water, and Seeing Everything a Black Hole's Ever Eaten

By: Ann Durham

Ann Durham — Thu, 22 Oct 2009 13:07:38 +0000

Yep, you are correct, methane is NOT stinky in its natural state. I'm the one who asked the question about space smelling, btw. And actually this wasn't what I meant. I hear on TV astronauts saying space smells like "fried steak" or "burnt toast". There's some sort of odor that lingers on the spacesuits after spacewalks that, even after coming back to earth, the astronauts will smell on the spacesuits. This was what I was referring to. Wondering what kind of smell that would be…maybe the smell of a "hot" spacesuit – after absorbing the sun's rays and being hot-hot and then cooling off after the spacesuit is back in the space shuttle. I don't know. Hum. This was what I was referring to. Anybody have any clues??

By: gas safety london

gas safety london — Fri, 19 Jun 2009 09:16:15 +0000

whatever happend to the LHC lol

By: Geoffrey

Geoffrey — Sat, 13 Jun 2009 05:51:47 +0000

Okay, I'm getting a little confused, and not a just a bit twitchy.

I've noticed several times that ya'll have referred to methane as "stinky." However, methane in its natural state is an odorless gas. Now, when it's ejected from a critter, it takes the… scenic route… getting out and picks up odors there. Also, when it's used for home heating, and odor is added to it, as a safety measure…

But, unless I completely misunderstand something… cosmic, free-floating methane should be odorless… Colorless, too, but pressure, refraction and a million other things probably mess with that.

By: Sebastien Sama

Sebastien Sama — Fri, 29 May 2009 01:33:00 +0000

Hello guys!!!
I'm a engineering undergraduate student in Montreal, Canada.
Just before I start I want to say this:

Your show is AMAZING!!!
In fact, I've been listening to it since 2006-2007!!
Thanks for all of those infos about science and astronomy!
Keep at it guys!!!

Now to the main dish:

I just wanted to address the last question in the show. You know, about the colour of hot bodies and the way we represent temperature.
You don't need to apologize Pamela for the way that we represent hot objects!!! (Sorry if I misspelled you name, you need to remember that my first language is French!!)

There is actually a very good reason for us to represent red as hot and blue as cold.
If you go back several thousands year, for our ancestors, fire was a dangerous thing. And since fire is red, we learn to recognize red as hot.
Same thing for blue, since ice, or water, tend to be blue and cold, we learn to recognize blue as cold.
The most interesting thing is that as the millenniums passed by and we learn to control fire, it made it possible to work with metal. And because of that, we had to learn that red isn't so hot since now the black bodies radiation physics apply.
The end result was that we created a set of colour that approach the real spectrum for hot bodies: blue then red then orange then yellow then white, with white being the hottest.
And this representation work very well if you think about our limited capabilities. (Since we wouldn't be able to look at a black bodies who's temperature is such that it appear blue without a filter to look at it!!!)

So that's the story about how we decided what colour represent what temperature.

I hope you enjoyed it!!

Thanks for all your show again!!

Seb.

By: Paul M.

Paul M. — Sat, 18 Apr 2009 17:40:35 +0000

the answer to the first question is a reification (fallacy). The fabric of space is a abstract concept, so it doesn't make any sense to say that gravity would pull on it, in the case of a big crunch of matter. No one is claiming that gravity is causing the exspansion of the universe, why would it cause a contraction of the universe?