Shownotes

Will traveling at light speed destroy the Universe?

• Is faster the light travel possible?


• Check out Episode 31 of Astronomy Cast, which discusses warp speed (among other things)


• Does gravity travel at the speed of light?


• BAUT forum discussion of infinite gravity


• Warp Drive and Cloaking Devices:  Not Just Science Fiction Anymore? –from Universe Today

Will Andromeda be ever be easily visible (and look really cool!) in our night sky?

• All about Andromeda- from SEDS


• When Galaxies Collide — from Harvard Smithsonian Center for Astrophysics


• Paper on The Collision Between the Milky Way and Andromeda

Will proton beams in the LHC be going twice the speed of light?

• Large Hadron Collider info


• All about Einstein’s theory of relativity — from the University of New South Wales

Does dark matter collapse into black holes?

• Why doesn’t dark matter fall into a black hole? — from Cornell University


• Greedy Supermassive Black Holes Dislike Dark Matter –from Universe Today


• How Dark Matter Might Have Snuffed Out the First Stars — from Universe Today


• Could the First Stars Have Been Powered by Dark Matter? — from Universe Today

Are black holes spinning?

• Black Holes Seen Spinning at the Limits Predicted by Einstein — from Universe Today


• Supermassive Black Holes Spin at the Limits of Relativity — from Universe Today


• Iron Can Help Determine if a Black Hole is Spinning — from Universe Today

Is it possible the Big Bang wasn’t the beginning of the Universe?

• Physicist Neil Turok:  Big Bang Wasn’t the Beginning — from Wired


• Thinking About Time Before the Big Bang — from Universe Today


• Before the Big Bang — from Universe Today


• What Was Before the Big Bang? — from Universe Today


• And it Came From the CMB — from Star Stryder


• The Improbable Universe — from Star Stryder


• The Universe In One Year — from Discovery Channel

Transcript: light speed, Andromeda galaxy, dark matter and black holes

Download the transcript

Fraser Cain: Welcome to the AstronomyCast Question Show. This is where we answer your questions about Space and Astronomy. All right – second week Pamela.

Dr. Pamela Gay: Second week – we’re going to try and keep doing this as long as we can, so keep sending us the questions.

Fraser: Yeah, the questions came pouring in. [Laughter]. We got quite a few in the last time. This week listeners asked: “Will reaching the Speed of Light destroy the Universe? When is Andromeda going to look really, really cool with the unaided eye? And why didn’t Dark Matter all just turn into Black Holes?”

There’s more. If you have a question for the AstronomyCast team, just e-mail it in to info@astronomycast.com and we’ll try and tackle it in a future show. Let’s get on with the first question.

Mohammad Murro?: When you reach the Speed of Light the Mass of an object increases to infinity which means that you would create Infinite Gravity. Causing Infinite Gravity, objects would accelerate towards that body approaching the Speed of Light. Would this cause the Universe to implode?

Fraser: I think I need to sorta break this up. We’ve got some Spaceship and it’s traveling faster and faster. As we know from Relativity as a Spaceship goes faster it takes more Energy, gains in Mass and as you approach the Speed of Light, the amount of Mass and Energy required approaches infinity. So I guess that’s our first problem, right?

Pamela: [Laughter] it’s just a small one, no big deal.

Fraser: Yeah, like is that even possible?

Pamela: Well, no you can’t actually get to the Speed of Light because of the whole infinite relativistic Mass problem. There are two different ways to look at the Mass of an object. The first is – what is the Mass that comes out of the number of Atoms it’s made out of? What’s the Mass that just comes from the fact that it exists?

Then the other Mass that you have to look at is the other Mass that comes out of its motion. You take the Energy of the object and that actually increases its Mass. So the more something is moving, the faster it is going the more relativistic Mass we talk about it having.

The way the equations work out if your velocity just happens to reach the Speed of Light then you end up dividing by zero, which goes to infinity. Dividing by zero is always a bad thing. Luckily things with Mass can’t get there. It just takes too much Energy to accelerate to that velocity.

Fraser: So the first part of the problem with this is that the premise is just not possible. If something could reach the Speed of Light then what would happen? Well, nothing can reach the Speed of Light so it’s really difficult to answer the “what would happen” because we’re way beyond what’s even possible by the Laws of Physics.

That’s fine you know we’ll just throw the Laws of Physics out. [Laughter] Let’s say like “what if” some piece of Mass was going the Speed of Light. Would it have an infinite amount of Mass?

Pamela: We think so according to the Math.

Fraser: Okay, so then you would have an infinite amount of Mass, would it then have an infinite amount of Gravity?

Pamela: Not so much. The equation says yes but what does that mean is the real issue. What it means is there is some sort of a Force and that Force is always pointing at this object that’s moving