Another week, another roundup of your questions. This week listeners asked: if forces are communicated through particles, can we run out? If you were traveling at light speed, when would you know to stop? And there's even more. If you've got a question for the Astronomy Cast team, please email it in to info@astronomycast.com and we'll try to tackle it for a future show.

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Hey sorry if you are getting a lot of emails on this, but thought I'd drop in and mention something that was mentioned in this Q&A show that might be wrong.

Referencing where I first learned this (and just double checked to make sure)
http://www.quackcast.com/
QuackCast 15. Magnet ‘Therapy’

Iron in the blood is non ferromagnetic.

This whole pod cast talks about this and more. He mentions this is why you can send people off for a MRI which often has a magnetic strength of around 20,000 Gauss. He goes on to say the thermal agitation from body heat is 10 million times stronger for agitating the atoms in your blood than a 250 Gauss magnet.

I have no idea what the strength is for the magnetic pull of the earth at any given location, but I'm willing to bet its effects on the Iron in your blood is next to zero.

Well, in this podcast, they were saying that while the Earth's magnetic field's effect on the iron in your blood is next to zero, it is technically not exactly zero. In practice, it is so close to zero that it might as well be zero, and they do not deny that fact.

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"For the world is hollow and I have touched the sky"

Ok, wow, talk about having a "duh" moment. I'm really glad you guys mentioned that photons do not experience time. I shook my head at the obviousness and could not believe that I hadn't even considered it before.

It led me to wonder though, considering all the odd things that happen as you approach the speed of light, might you just end up being light (due to whatever methods you used to get to that speed) and therefore be able to travel at the speed of light? Ok, so you'd never be able to go back to your normal state but if you could travel intact, at the speed of light, you'd never be able to stop anyway so who cares.

Also, if I was somehow able to convert all my mass to energy, I would be traveling at light speed right? Of course I wouldn't be me anymore, but everything that was me would still exist and all of me would be traveling at light speed. So it is possible, right? Pointless, but possible?

Anyway, thanks again for "baking my noodle". This concept of light being timeless is going to have me pondering many naive thoughts for quite some time.

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The only way of finding the limits of the possible is by going beyond them into the impossible.

Arthur C. Clarke

The Brain Science Podcast

I could not recall if there had been a show exclusively devoted to light. I looked for one but did not find it. I know it's discussed all the time, but isn't it odd that an astronomy show hasn't had one show devoted exclusively to light? I apologize if I missed it, and if it exists please point it out. Thanks!

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The only way of finding the limits of the possible is by going beyond them into the impossible.

Arthur C. Clarke

The Brain Science Podcast