Angular Momentum, Cosmic Time Dilation & Dark Matter Mysteries Unraveled | Q&A

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Andrew Dunkley: Hi there. This is Space Nuts, A, uh, Q

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and A edition. My name is Andrew Dunkley,

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your host. Great to have your company. Hope

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you're well. Coming up on this episode,

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Fred Watson will be answering questions about

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angular momentum. The age of the

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universe versus the perception of time.

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That's an interesting one. The vastness of

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space and the big leap.

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Stick around. We'll deal with all of that

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coming up soon on this edition of space

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nuts.

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Mark Rabelais: 15 seconds. Guidance is internal.

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Professor Fred Watson: 10, 9. Ignition

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sequence. Star space nuts.

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Andrew Dunkley: 5, 4, 3.

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Professor Fred Watson: 2. 1.

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Andrew Dunkley: 2, 3, 4, 5, 5, 4, 3, 2,

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1. Space nuts.

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Mark Rabelais: Astronauts report it feels good.

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Andrew Dunkley: And we welcome him back once more. It's

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Professor Fred Watson Watson, astronomer at

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large. Hello, Fred Watson.

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Professor Fred Watson: Hello, Andrew. How you doing? Seeing you

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here.

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Andrew Dunkley: Yeah. So unusual.

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Professor Fred Watson: Doing all right?

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Andrew Dunkley: Seems like ages since we last spoke.

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Professor Fred Watson: Yes.

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Andrew Dunkley: Could have been a few seconds, though. Who

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knows? We will be talking about time shortly,

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so maybe the answer is in there.

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Um, let's get down to business.

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Uh, this first, uh, question comes from

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Mark. Now, uh, it's actually two

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questions about angular momentum. But, uh,

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Mark,

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he's sort of weeding this one out a little

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bit. Uh, so, um, let's find out what he

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wants to know.

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Mark Rabelais: Hello, fellas. My name is Mark

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and I reside in Baton Rouge,

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Louisiana. My question,

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my first question has to do with

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the two black holes that were

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very rapidly orbiting each other

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just before they merged. And each of

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those black holes presumably had

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its own angular momentum and

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was spinning, in a

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certain sense, either clockwise

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or counterclockwise. And,

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uh, my question is,

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if these two black holes,

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as unlikely as it might be,

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happened to be spinning

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with equal

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rates but in opposite

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directions in such a way that

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the net angular

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momentum of the combined system

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would be zero. Then would

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the final new black hole

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created have an angular momentum of zero?

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Not sure if I posed that correctly. But I'm

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sure you get what I'm saying, what I'm

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meaning here. Could the

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resulting black hole have a net angular

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momentum of zero? And if so,

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would that result in any unusual

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characteristics if a

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black hole was not spinning?

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Anyhow, that's my first question. My second

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question has to do with the

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universe writ large. Um,

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wouldn't the universe have a

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net angular momentum when the Big

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Bang occurred? I presume.

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Although I don't understand why there would

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be a non zero

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angular momentum of the entire universe.

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If the Big Bang

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was perfectly symmetric, the net

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angular momentum should be zero, should

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it not? And, uh,

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of course the Big Bang

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was not perfectly symmetric. And that is what

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I understand is the reason

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for the uh, clumping of matter

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as shown in the WMAP image.

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I guess I'm getting too

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off, off the beaten path here. But anyhow,

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uh, it has to. My question is,

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does the universe

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have a net angular momentum and

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what's the implications of that either way,

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whether it does or does not? Anyhow,

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see that's why I stay awake at night.

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Okay guys, love uh, your podcast. Uh,

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take care.

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Andrew Dunkley: Thank you Mark. Yeah, there's a lot packed

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into those, um, those ideas from Mark

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Fred Watson.

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Double barrel Question. Um, we'll start off

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with the two black holes merging with equal

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rate in opposite directions.

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Would uh, they

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achieve uh, zero angular

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momentum under those special circumstances?

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Professor Fred Watson: Uh, and the answer is yes, yes they could.

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Um, so there are two things at play here.

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Uh, one is the individual spin of each

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black hole. Uh, most black holes

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are spinning, uh, and

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so those two, um,

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the angular momentum of those two of each

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black hole when they collide,

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uh, it could be that they'll cancel out if

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they're rotating at the same rate in the

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opposite direction. Now normally, um,

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that's unlikely to happen because

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uh, you know, it will be very, very

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unusual to have two black

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holes with exactly the same rotation rate but

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one the negative of the other one rotating in

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the opposite direction. But it could happen.

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It could happen. But the bigger phenomenon

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uh, is actually the

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orbital angular momentum of the

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two black holes as they spin together.

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Uh, that's where most of the angular

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momentum in a binary black hole, a

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pair of black holes, that's where most of it

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lies, um, when they collide.

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What happens to that angular uh,

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momentum? Well it is radiated away

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in gravitational waves. And that's one of

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the things that is taken into account when

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people look at a gravitational wave signal

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coming from two colliding black holes.

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Um, the angular

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momentum gives rise to the um,

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change in angular momentum is one of the

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things that gives rise to the, to the uh,

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gravitational waves that are observed. And

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that's all modelled and all makes complete

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sense. Uh, so um, in particular

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though, um, that means that that's the

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biggest component of spin. The

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individual spin of each black holes is a

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smaller one. Uh, but still,

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um, it basically is uh, exactly

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as Mark has postulated. Uh, they

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could cancel out completely what happens to

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the angular momentum. Once again it, it is

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radiated out in the form of gravitational

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waves. That's where the angular momentum

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goes. It's a form of energy and that comes

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out as energy that we can now measure with

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our ah, gravitational wave detectors.

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And turning to part two, which I

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Andrew Dunkley: think, yes, the universe

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um, yeah. Ah, assuming that

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it radiated, radiated out in all directions

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simultaneously in a spherical

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way, um, would it have and

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should it not have m net 0 angular momentum?

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Professor Fred Watson: And apparently it does, uh, in the

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sense that, uh, it has never.

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There's no evidence for a

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rotation of the universe as a whole.

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Um, Mark, again is on absolutely the right

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track because, uh, if there was

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a rotation in the universe, you'd

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expect to see particular

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patterns within the cosmic microwave

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background radiation, which is what he

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mentioned in relation to wmap, the Wilkinson

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Microwave Wave Anisotropy Probe.

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And, uh, we don't see that. We don't see, um,

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characteristics that would suggest that the

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universe is rotating. So it looks as though

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there was enough symmetry in the Big Bang

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itself, uh, that no rotation

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was imparted to the universe. One of the

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other issues with this, of course, is

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if it was rotating, then you

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have to, um,

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basically invoke a central point,

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uh, and an absolute reference frame. And

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neither of these things are permitted in our,

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uh, normal cosmological theories. Uh,

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so it's just as well that it's not there.

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And it's the fact that we don't see any

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rotation that allows us to ignore the

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idea of an absolute reference frame. Uh, we

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just take the universe as a whole.

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Andrew Dunkley: It's like a snow globe. Like the snow

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globe's got no angular momentum, but

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everything inside's doing all sorts of busy

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stuff.

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Professor Fred Watson: Uh, yes, that's right. That's a very nice way

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to put it. Um, you'll go far, Andrew, with

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analogues like that.

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Andrew Dunkley: I went to a tourist shop to figure that out.

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Yeah,

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Professor Fred Watson: you've got to choose the right snow globe.

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That's right.

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Andrew Dunkley: Did you know that people who invented snow

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globes never, ever, to this day, it's still

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a trade secret revealed what the glittery

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stuff inside a snow globe is.

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Professor Fred Watson: No, I didn't know. That's true.

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Andrew Dunkley: Look m it up. The

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original inventors and the family that

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started it still has control

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of, um, uh, the invention to this

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day have never ever

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revealed what is inside a snow

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globe. What makes all the glittery

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snow like effect. They've never

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told anybody. Uh, I think it's the same

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stuff they put on KFC nuggets. But

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I, uh, could be wrong. I could be

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wrong. Secret herbs and spices,

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maybe. Uh, thank you, Mark. A very thoughtful

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question. Uh, and it sounds like, um, you're

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on the money so you can actually go to sleep

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tonight. Uh, well done.

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Uh, our next question, Fred Watson, comes

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from John. Does the age of the universe

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depend on the gravity well, that you

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exist within. If Andrew was living on a

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planet orbiting a super massive black hole,

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eg. Sagittarius, a star, uh,

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time would be slower for him relative to

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Fred Watson living on Earth. Would Andrew

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then calculate the age of the universe, the

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universe to be less than what Fred Watson

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does? That one comes from John. That's a good

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one. That's a what if question.

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Professor Fred Watson: It is. We should try it out

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one day. Yeah, uh, you can be the one

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going and living on the black hole.

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Andrew Dunkley: Yeah, uh, that I don't think it'd be a very

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long lived situation. But uh, you know,

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yeah, I'm happy to, happy to give it a

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whirl.

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Professor Fred Watson: So um, turning to the um,

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um, the answer to John's uh,

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conundrum. Uh, the, the answer is yes, there

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is gravitational time dilation.

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So if you were, you know, if

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you were hanging around a black hole, you'd

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think the universe would have a

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younger age than an

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observer in deep empty space.

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But uh,

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it is a small effect

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compared with the size of the universe

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at uh, large. So what we do is

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we treat the age of the universe as a,

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basically as a

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universal constant. And you can sort

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of imagine um, when we look at

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for example the cosmic microwave background

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radiation, we look around the whole sky

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and we see the flash of the Big

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Bang and we assume that it's the same age in

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all directions. Uh, and

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that's basically what we do.

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We take, we take uh, the

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flash of the Big Bang as being our uh,

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yardstick for the 13.8 billion

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years age of the universe. And

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that's so it irons out, if I can put it that

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way. This is the global view that irons out

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all the local funny uh, gravitational

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effects like you hanging around a black hole

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and seeing a younger universe. This is

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um, what you might call um, a

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measurement made in a, in a, in a

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preferred reference frame. You're just

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talking about reference frames in terms of a

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rotating universe. This is the same issue.

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This is the, the sort of standard reference

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frame of the universe kind of defined by the

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cosmic microwave background radiation. Um,

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and so gravitational effects on that whole

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picture are ah, minimal compared with what

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might be felt when you were very close to

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something with a very high gravity.

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Andrew Dunkley: Okay, all right. I, I was surprised that

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it went the way you said because I was,

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I thought you were going to say no. For me,

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time will pass as it would anywhere else.

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It's just, you know, to the observer it would

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be different. You wouldn't be moving.

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Um, but, no but

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from the inside it would

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Be different because what you're looking at

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on the outside would

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age, uh, slower, therefore seem younger. Is

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that what you said?

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Professor Fred Watson: Yes, that's right. So, so the, um.

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It is, it's, you know, you're, you're

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observing from a different reference frame

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when you're hanging around the black hole.

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Uh, and that's. And so that it's. I mean, we

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normally think, you know, we talk about

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people falling into a black hole and they.

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Time stops on the event horizon

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as they cross the event horizon.

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Uh, but that's how we normally think about

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these things. But if you, if you, if you

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yourself are in the black hole, then it looks

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as though the whole universe is doing

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different things like becoming younger

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and things of that sort.

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Andrew Dunkley: Extraordinary.

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Professor Fred Watson: Yeah.

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Andrew Dunkley: It's just such a weird place, isn't

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Professor Fred Watson: it, when you're very weird. Yes.

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Andrew Dunkley: All right, John, Uh, great question. And, uh,

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yeah, the answer was yes. This is Space Nuts

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with Andrew Dunkley and Professor Fred Watson

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Watson. A Q and A edition.

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Mark Rabelais: Space Nuts.

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Andrew Dunkley: Okay, Fred Watson, our, uh, next storey

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comes from Pete, who says hi.

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Great show. Well done. Oh, thank you.

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Um, in trying to understand the impact of

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dark matter matter on the stability of the

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galaxy, I was perplexed by the lack of

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reported impact on our solar system. And

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then closer to home, the Earth, the moon and

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space traffic, uh, that

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led me to a, uh, realisation that whilst we

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see visual images of galaxies that look full,

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that in reality, if all the

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baryonic matter in the galaxy was accumulated

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together, it would represent a minuscule

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percentage of the volume of the galaxy. That

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the galaxy may have 100 billion stars

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but is basically empty. Dark

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matter, whatever it turns out to be, is

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likewise so sparsely distributed that

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it is undetectable at the solar system

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level. Maybe the professor, uh, could expand

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on these comments for the benefit of all of

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us who struggle to grasp the vastness of

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empty space that constitutes the galaxy and

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ultimately the universe. Many thanks from

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Pete. What do you reckon, Fred Watson?

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Professor Fred Watson: Well, Pete's right as well. Uh, we've done

355
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really well today. We've had three

356
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speculations, all of which have turned out to

357
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be on the money. Um, it's the fact that,

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um, dark matter, whilst we know it,

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clumps. It clumps on

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scales that are much bigger than the galaxy.

361
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So our galaxy is in a blob of dark

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matter that, um, actually, uh, is

363
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much, uh, you know, much bigger

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than the galaxy itself. So what that means

365
00:16:10.960 --> 00:16:13.840
is that, um, exactly

366
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as Pete says, you've got a uni,

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to all intents and purposes, within the solar

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system. And actually within the

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galaxy itself too, you've got the kind of

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uniform background of dark matter whose

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00:16:27.480 --> 00:16:30.440
gravitational influence, uh, is

372
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there, but is kind of acts

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equally in all directions to stuff that's

374
00:16:36.510 --> 00:16:39.310
immersed in it, if I can put it that way. So,

375
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yes, the solar

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system is full of dark matter, um, but it's

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effectively uniform. It's just like a

378
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background uniformity, which is why

379
00:16:52.030 --> 00:16:53.990
when we calculate the orbits of planets and

380
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things like that, we can completely ignore it

381
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because it's essentially a flat

382
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space of, uh, of uniform

383
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gravitational influence, if I can put it that

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00:17:05.000 --> 00:17:06.440
way. I don't think I'm explaining that very

385
00:17:06.440 --> 00:17:08.640
well, but that's the bottom line. And it's

386
00:17:08.720 --> 00:17:10.880
basically. It's exactly what Pete said.

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Andrew Dunkley: And what did he say?

388
00:17:15.839 --> 00:17:17.200
Professor Fred Watson: He said what I've just said,

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that the, the blob of dark matter that the

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00:17:21.640 --> 00:17:24.400
galaxy's in is effectively uniform on

391
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distances, uh, comparable with the, the

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solar system and in fact on distances

393
00:17:29.130 --> 00:17:31.130
comparable with the stars in the galaxy as

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well.

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Andrew Dunkley: Yeah, it's seems to be a need of

396
00:17:34.330 --> 00:17:37.130
dark matter to have stuff

397
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to hang around.

398
00:17:39.290 --> 00:17:41.090
Professor Fred Watson: Yes. With. We think it's the other way

399
00:17:41.090 --> 00:17:43.770
around. We think that the stuff gravitated

400
00:17:43.930 --> 00:17:46.690
inwards, being pulled because of the

401
00:17:46.690 --> 00:17:48.370
glut. The dark matter. That's right. And

402
00:17:48.370 --> 00:17:51.130
that's what caused galaxies to form.

403
00:17:51.830 --> 00:17:54.230
Uh, sort of built on a scaffolding of dark

404
00:17:54.230 --> 00:17:56.550
matter, which was what was created in the big

405
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bone.

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Andrew Dunkley: Right. Wow. Okay. That

407
00:18:00.150 --> 00:18:02.510
just makes it even more mysterious

408
00:18:02.910 --> 00:18:05.310
really, doesn't it?

409
00:18:06.450 --> 00:18:09.310
Professor Fred Watson: Um, well, it neatly explains

410
00:18:09.310 --> 00:18:12.110
why galaxies are there because that, you

411
00:18:12.110 --> 00:18:14.870
know, it's very convenient. It is convenient

412
00:18:14.870 --> 00:18:17.320
to have galaxies. Yeah. That the,

413
00:18:17.640 --> 00:18:20.320
this sort of web like structure, uh,

414
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which we think dark matter,

415
00:18:22.710 --> 00:18:25.280
um, you know, that was the shape of dark

416
00:18:25.280 --> 00:18:27.400
matter. It was like a honeycomb of material,

417
00:18:28.040 --> 00:18:30.360
except it's not material as we know it.

418
00:18:30.770 --> 00:18:33.520
Um, that web like structure is actually

419
00:18:33.520 --> 00:18:35.800
a direct consequence of the Big bang. It's

420
00:18:35.800 --> 00:18:38.200
what we expect. It's what we expect the big

421
00:18:38.200 --> 00:18:40.900
bang to do. Um, and, uh,

422
00:18:40.920 --> 00:18:42.040
Jordi agrees with that.

423
00:18:42.040 --> 00:18:43.920
Andrew Dunkley: Yes, he does have noticed.

424
00:18:43.920 --> 00:18:45.880
Professor Fred Watson: Yeah, he's upset because.

425
00:18:46.760 --> 00:18:48.960
Andrew Dunkley: Yeah, he, he's, he's dealing with a dark

426
00:18:48.960 --> 00:18:51.840
matter by the sound of it. Poor old

427
00:18:51.840 --> 00:18:52.200
Jordy.

428
00:18:52.200 --> 00:18:54.360
Professor Fred Watson: Jordy. It's all right. It's okay.

429
00:18:54.360 --> 00:18:55.160
Andrew Dunkley: It's okay.

430
00:18:55.240 --> 00:18:57.200
Professor Fred Watson: Yeah, his tail's gone up again. It was very

431
00:18:57.200 --> 00:18:59.840
down the second ago. Yeah.

432
00:18:59.840 --> 00:19:01.320
Andrew Dunkley: We were talking about dark matter and

433
00:19:01.320 --> 00:19:03.160
Professor Fred Watson: that's, that's what he is.

434
00:19:03.240 --> 00:19:03.720
Andrew Dunkley: Yes.

435
00:19:03.880 --> 00:19:06.640
Professor Fred Watson: Very dark indeed. Probably the blackest thing

436
00:19:06.640 --> 00:19:07.880
in the whole house. Yes.

437
00:19:09.630 --> 00:19:12.490
Andrew Dunkley: Um, I, I know there's. We get so

438
00:19:12.490 --> 00:19:14.770
many Questions about dark matter and, and

439
00:19:14.930 --> 00:19:17.050
dark energy and black holes. It's, um,

440
00:19:18.370 --> 00:19:21.170
probably the top three things that people ask

441
00:19:21.170 --> 00:19:24.090
us about. And, and

442
00:19:24.090 --> 00:19:25.890
Jordy. We ask about Georgie all the time.

443
00:19:25.890 --> 00:19:28.450
Sarah. Um, but, yeah, you know,

444
00:19:30.850 --> 00:19:33.810
just never ceases to amaze me

445
00:19:33.810 --> 00:19:36.790
that there are, like,

446
00:19:36.790 --> 00:19:39.030
how long ago didn't we even know about dark

447
00:19:39.030 --> 00:19:41.030
matter? And now we've started thinking, well,

448
00:19:41.030 --> 00:19:42.950
okay, it's, it's doing a lot more than we

449
00:19:43.510 --> 00:19:46.350
ever anticipated. And now we seem to have a

450
00:19:46.350 --> 00:19:48.070
total reliance on it to keep everything

451
00:19:48.070 --> 00:19:49.790
together. It's the, it's the glue of the

452
00:19:49.790 --> 00:19:50.310
universe.

453
00:19:51.230 --> 00:19:53.750
Professor Fred Watson: Um, it's a good way to put it.

454
00:19:53.750 --> 00:19:54.710
Andrew Dunkley: Yeah, yeah.

455
00:19:56.310 --> 00:19:59.190
Professor Fred Watson: What? Write a book. Should be on

456
00:19:59.190 --> 00:19:59.670
radio.

457
00:19:59.670 --> 00:20:00.740
Andrew Dunkley: All right, yes,

458
00:20:03.530 --> 00:20:06.050
maybe one day. Uh, but, um. You think they'll

459
00:20:06.050 --> 00:20:07.650
ever crack it? I've probably asked that

460
00:20:07.650 --> 00:20:10.570
question many times, but, um, you know,

461
00:20:10.970 --> 00:20:12.450
do you think they'll ever figure out what

462
00:20:12.450 --> 00:20:14.810
this is and how it all came to be?

463
00:20:15.850 --> 00:20:17.210
Professor Fred Watson: Yeah, I think so.

464
00:20:17.210 --> 00:20:19.050
And, you know, there's, there's ideas buzzing

465
00:20:19.050 --> 00:20:20.530
around all the time. We talked not very long

466
00:20:20.530 --> 00:20:23.290
ago about the idea that suddenly people are

467
00:20:23.370 --> 00:20:26.170
suspecting that, um, primordial

468
00:20:26.170 --> 00:20:29.170
black holes might be a reality. And, uh, they

469
00:20:29.170 --> 00:20:31.290
can come in any size you like, rather than

470
00:20:31.290 --> 00:20:33.510
have to be bigger than the size of the sun.

471
00:20:34.140 --> 00:20:36.750
Uh, and so one that's smaller than the sun

472
00:20:36.750 --> 00:20:39.310
has been found. Uh, and that suggests that

473
00:20:39.310 --> 00:20:41.910
primordial black holes may exist. And that

474
00:20:41.910 --> 00:20:43.790
might open the whole debate again about

475
00:20:43.790 --> 00:20:46.510
whether, uh, dark matter is made of

476
00:20:46.510 --> 00:20:49.230
machos or wimps, uh, with the machos

477
00:20:49.230 --> 00:20:51.990
being massive compact halo objects. That's

478
00:20:52.150 --> 00:20:54.430
things like black holes. And the wimps are

479
00:20:54.430 --> 00:20:56.830
weakly interacting massive particles, which

480
00:20:56.830 --> 00:20:59.670
is kind of the preferred view now.

481
00:20:59.830 --> 00:21:01.550
And then on top of that, there's the

482
00:21:01.550 --> 00:21:03.230
possibility that we've got it all wrong

483
00:21:03.230 --> 00:21:05.810
anyway, uh, that it might be

484
00:21:05.970 --> 00:21:08.450
actually modified Newtonian dynamics that

485
00:21:08.530 --> 00:21:11.490
work. So it's

486
00:21:11.490 --> 00:21:14.010
still some open questions with regard to dark

487
00:21:14.010 --> 00:21:15.770
matter. And we've been thinking about this

488
00:21:15.770 --> 00:21:18.610
seriously, uh, for almost

489
00:21:18.610 --> 00:21:21.530
the last 50 years. It was 1978 when Vera

490
00:21:21.530 --> 00:21:24.490
Rubin's observations really hit home,

491
00:21:24.490 --> 00:21:26.570
that there was something very basic about the

492
00:21:26.570 --> 00:21:27.730
universe that we didn't understand.

493
00:21:29.010 --> 00:21:31.250
Andrew Dunkley: Like how wasn't it throwing itself to pieces?

494
00:21:31.840 --> 00:21:32.640
Professor Fred Watson: Yes, that's right.

495
00:21:32.720 --> 00:21:33.440
Andrew Dunkley: That was the question.

496
00:21:34.000 --> 00:21:36.520
Professor Fred Watson: That question was asked by Ken Freeman, who's

497
00:21:36.520 --> 00:21:38.440
an Australian astronomer. He, he, uh,

498
00:21:38.440 --> 00:21:41.360
published a paper in 1970 which was

499
00:21:41.360 --> 00:21:43.920
saying galaxies are rotating too fast to stay

500
00:21:43.920 --> 00:21:46.740
together. Yeah, um,

501
00:21:46.740 --> 00:21:49.080
Vera postulated that there are halos of stuff

502
00:21:49.080 --> 00:21:51.040
that keep them together. And that's when the

503
00:21:51.040 --> 00:21:53.960
whole dark matter, um, vogue, if I can

504
00:21:53.960 --> 00:21:56.920
put it that way, started yeah, and it's, it's

505
00:21:56.920 --> 00:21:59.440
Andrew Dunkley: still the big question, isn't it? Uh,

506
00:21:59.900 --> 00:22:01.940
one of several, but, yeah, one of the biggest

507
00:22:01.940 --> 00:22:04.620
ones. Uh, thank you, Pete. Great question,

508
00:22:04.700 --> 00:22:06.700
and, uh, thanks for sending it in.

509
00:22:09.260 --> 00:22:11.140
Okay, we've had a problem here.

510
00:22:11.140 --> 00:22:11.740
Professor Fred Watson: This is Houston.

511
00:22:11.740 --> 00:22:12.540
Andrew Dunkley: Say again, please.

512
00:22:16.860 --> 00:22:18.860
Okay, standby 13. We're looking at it.

513
00:22:18.860 --> 00:22:21.500
Spacebuds, our final question

514
00:22:21.660 --> 00:22:23.180
comes from, uh, uh, you were saying,

515
00:22:23.180 --> 00:22:24.990
Fred Watson, that we. We've been right on the

516
00:22:24.990 --> 00:22:27.430
money. These questions have been, you know,

517
00:22:27.430 --> 00:22:29.830
spot on until now.

518
00:22:30.390 --> 00:22:33.280
Berman Gorvine: Hello, space nuts. Uh,

519
00:22:34.150 --> 00:22:36.950
Martin Berman Gorvine here, writer

520
00:22:37.190 --> 00:22:39.350
extraordinaire in many

521
00:22:39.750 --> 00:22:42.390
genres, here to accept

522
00:22:43.750 --> 00:22:45.830
Professor Watson's thanks

523
00:22:46.470 --> 00:22:49.110
for the Bee Gees

524
00:22:49.110 --> 00:22:52.070
quip. And I'm asking

525
00:22:52.150 --> 00:22:54.070
today about another

526
00:22:55.030 --> 00:22:57.950
BG brother. This

527
00:22:57.950 --> 00:23:00.630
one, uh, may not even exist,

528
00:23:01.350 --> 00:23:04.190
and I know that, nonetheless, you

529
00:23:04.190 --> 00:23:06.710
have gotten questions about him before.

530
00:23:07.590 --> 00:23:10.390
And that would be Peel, Give.

531
00:23:11.510 --> 00:23:13.510
Yes, Peel, Give,

532
00:23:14.390 --> 00:23:16.150
otherwise known as

533
00:23:17.310 --> 00:23:18.910
the Big Leap.

534
00:23:20.830 --> 00:23:22.750
Can you somehow

535
00:23:24.190 --> 00:23:25.070
circumvent

536
00:23:27.630 --> 00:23:30.110
the absolute speed

537
00:23:30.110 --> 00:23:31.150
limit of

538
00:23:33.790 --> 00:23:36.190
the speed of light in the

539
00:23:36.190 --> 00:23:39.070
universe by having

540
00:23:39.630 --> 00:23:42.430
a, ah, quick, uh, dodge out

541
00:23:42.510 --> 00:23:45.240
into another universe where the speed

542
00:23:45.390 --> 00:23:48.110
speed of light is arbitrarily high,

543
00:23:48.750 --> 00:23:51.070
which is a staple of

544
00:23:51.790 --> 00:23:54.660
science fiction? Um,

545
00:23:54.660 --> 00:23:56.830
is this theoretically possible?

546
00:23:57.800 --> 00:24:00.270
Um, and even if it were,

547
00:24:00.590 --> 00:24:03.590
would it be possible to go have

548
00:24:03.590 --> 00:24:06.190
a visit with Mr. Peel Gibb

549
00:24:06.430 --> 00:24:08.910
without being spaghettified

550
00:24:09.230 --> 00:24:12.050
and turned into, um,

551
00:24:12.270 --> 00:24:14.670
mush of particles without even

552
00:24:15.230 --> 00:24:16.510
marinara thought?

553
00:24:17.950 --> 00:24:19.950
Can't wait for the answer.

554
00:24:20.430 --> 00:24:22.830
Berman Gourvine, over

555
00:24:23.150 --> 00:24:24.590
and out.

556
00:24:26.500 --> 00:24:28.790
Andrew Dunkley: Uh, thank you, Martin. I think he just

557
00:24:28.790 --> 00:24:31.590
brought our, um, podcast episode back

558
00:24:31.590 --> 00:24:33.950
to kind of the average

559
00:24:34.190 --> 00:24:36.990
sphere in terms of. No, no,

560
00:24:37.070 --> 00:24:39.970
I'm kidding. Um, love you, Martin. Love

561
00:24:39.970 --> 00:24:42.850
you very much. Um, Peel Gibb. Peel

562
00:24:42.850 --> 00:24:45.610
Gibb. The, um, the Big leap. So

563
00:24:45.930 --> 00:24:48.370
I think I'm just trying to. I'm scratching my

564
00:24:48.370 --> 00:24:51.050
head here. I, I think he's asking, is

565
00:24:51.290 --> 00:24:53.770
the absolute speed limit of light

566
00:24:53.850 --> 00:24:56.810
constant? If you could go and

567
00:24:56.810 --> 00:24:59.210
visit another. Another universe in

568
00:24:59.370 --> 00:25:00.970
comparison. Is that what he meant?

569
00:25:01.370 --> 00:25:03.290
Professor Fred Watson: That's the bottom line of this question.

570
00:25:03.370 --> 00:25:03.850
Yeah.

571
00:25:04.410 --> 00:25:06.610
Andrew Dunkley: One answer for this, and it could be one or

572
00:25:06.610 --> 00:25:07.050
the other.

573
00:25:07.520 --> 00:25:08.880
Professor Fred Watson: Well, it is. It's, It's. No,

574
00:25:10.240 --> 00:25:13.080
but, um, you know, just thinking aloud on

575
00:25:13.080 --> 00:25:15.360
that. So, uh,

576
00:25:15.920 --> 00:25:18.840
first of all, it is possible that in, if

577
00:25:18.840 --> 00:25:20.680
there were other universes, some of the

578
00:25:20.680 --> 00:25:22.760
fundamental physical constants might be

579
00:25:22.760 --> 00:25:24.840
different. The charge on the electron might

580
00:25:24.840 --> 00:25:26.200
be different, the speed of light might be

581
00:25:26.200 --> 00:25:28.640
different. Um, that's

582
00:25:29.200 --> 00:25:31.720
something we, we know so little about other

583
00:25:31.720 --> 00:25:33.240
universes, mainly because we don't know

584
00:25:33.240 --> 00:25:34.720
whether they exist, and there isn't really

585
00:25:34.720 --> 00:25:36.990
any theoretical framework that says they do.

586
00:25:37.580 --> 00:25:39.310
Uh, they have been suggested by some very

587
00:25:39.310 --> 00:25:42.190
eminent people, but we really don't have any

588
00:25:42.190 --> 00:25:44.710
more than suggestions. People have looked for

589
00:25:44.710 --> 00:25:47.030
evidence for other universes in the cosmic

590
00:25:47.030 --> 00:25:48.670
microwave background radiation that we're

591
00:25:48.670 --> 00:25:51.230
talking about a few minutes ago. Um, but

592
00:25:51.870 --> 00:25:54.710
unless you have an eye of faith, which one or

593
00:25:54.710 --> 00:25:56.430
two people do, there's not really anything

594
00:25:56.430 --> 00:25:59.260
there, nothing to see there. So um,

595
00:25:59.260 --> 00:26:01.750
other universes may well not exist and even

596
00:26:01.750 --> 00:26:04.050
if they do they might end up having the same

597
00:26:04.050 --> 00:26:06.850
speed of light. We simply do not know. But I

598
00:26:06.850 --> 00:26:09.810
think the main problem is going to be getting

599
00:26:10.050 --> 00:26:13.010
from ours into another one. Uh because the

600
00:26:13.010 --> 00:26:15.250
word universe means everything we can see and

601
00:26:15.250 --> 00:26:18.210
observe or deal with. Uh,

602
00:26:18.369 --> 00:26:21.090
and you know, um, transferring

603
00:26:21.090 --> 00:26:23.650
from this universe into another one I

604
00:26:23.650 --> 00:26:26.290
suspect is one that would, with

605
00:26:26.850 --> 00:26:28.930
even with the most open minded science

606
00:26:28.930 --> 00:26:31.570
fiction uh, brain in the world,

607
00:26:32.220 --> 00:26:35.150
um, might cause problems. Uh, unless

608
00:26:35.150 --> 00:26:37.030
you're Martin. Martin will cheerfully write

609
00:26:37.030 --> 00:26:39.790
about it and um, I hope it's a bestseller.

610
00:26:40.910 --> 00:26:42.030
Andrew Dunkley: I don't doubt it.

611
00:26:42.040 --> 00:26:43.700
Professor Fred Watson: Um, I've read a bit of uh,

612
00:26:43.700 --> 00:26:46.110
Andrew Dunkley: Martin's work and I've thoroughly enjoyed it.

613
00:26:46.190 --> 00:26:49.110
So uh, yeah, I would encourage to

614
00:26:49.110 --> 00:26:51.830
look up his books. Um, there's a few

615
00:26:51.830 --> 00:26:54.590
goodies there. Um, yeah.

616
00:26:55.150 --> 00:26:57.390
The speed of light intrigues me because

617
00:26:58.670 --> 00:27:01.070
we know what it is, we know how fast it is,

618
00:27:01.070 --> 00:27:03.550
what 300,000 kilometres per second or,

619
00:27:03.980 --> 00:27:06.620
or whatever. Um, and

620
00:27:07.500 --> 00:27:10.380
we can't even think about

621
00:27:10.460 --> 00:27:12.620
going near that speed. I mean we can't even

622
00:27:12.620 --> 00:27:15.590
achieve what, 2% of the um,

623
00:27:16.060 --> 00:27:17.580
relativistic speed.

624
00:27:18.580 --> 00:27:20.580
Uh, and if we could that'd be a major

625
00:27:20.580 --> 00:27:23.100
achievement. But um, it's,

626
00:27:23.100 --> 00:27:25.600
it's, it's an uh,

627
00:27:25.600 --> 00:27:28.500
unfathomable number in the scheme of

628
00:27:28.500 --> 00:27:28.700
things.

629
00:27:28.700 --> 00:27:31.550
Professor Fred Watson: Fred Watson. It is. Um, and you

630
00:27:31.550 --> 00:27:34.310
know the very good reasons for believing that

631
00:27:34.310 --> 00:27:36.590
nothing can go faster than that. And that's

632
00:27:36.590 --> 00:27:39.190
because as you accelerate things,

633
00:27:39.590 --> 00:27:41.990
any object with mass, as you accelerate it,

634
00:27:42.630 --> 00:27:45.430
uh, uh, the more

635
00:27:45.430 --> 00:27:47.750
energy it takes. So uh, you know, every

636
00:27:48.310 --> 00:27:51.310
metre per second per second that you add

637
00:27:51.310 --> 00:27:53.910
to its velocity, um, you

638
00:27:54.310 --> 00:27:57.270
kind of have huge energy penalties and

639
00:27:57.270 --> 00:28:00.170
eventually in order it all sort of um,

640
00:28:00.290 --> 00:28:02.610
basically asymptotes to infinity.

641
00:28:03.090 --> 00:28:05.090
In other words you'd have to put infinite

642
00:28:05.090 --> 00:28:08.010
energy into something, uh, to accelerate

643
00:28:08.010 --> 00:28:09.450
something to the speed of light. And we

644
00:28:09.450 --> 00:28:11.890
haven't got infinite energy so we're never

645
00:28:11.890 --> 00:28:14.410
going to do it. Um, there'd be other problems

646
00:28:14.410 --> 00:28:17.330
as well. Uh, so it is a real speed limit.

647
00:28:17.580 --> 00:28:20.330
Uh, it's very sad from the point of view

648
00:28:20.330 --> 00:28:22.450
of science fiction writers or from

649
00:28:23.090 --> 00:28:25.450
scientists. Uh, you've got to find a way of

650
00:28:25.450 --> 00:28:27.240
getting around it. I'm think you're a dab

651
00:28:27.240 --> 00:28:29.560
hand at that. So um, but that's What?

652
00:28:29.720 --> 00:28:32.320
Andrew Dunkley: I can't reveal anything. I'm just in the last

653
00:28:32.320 --> 00:28:34.480
couple of chapters of my trilogy and I'm not.

654
00:28:34.480 --> 00:28:36.400
No, I'm not going to blow the whistle on

655
00:28:36.400 --> 00:28:36.840
myself.

656
00:28:36.840 --> 00:28:38.920
Professor Fred Watson: No, no, don't do that. Don't do that.

657
00:28:38.920 --> 00:28:41.920
Andrew Dunkley: But, yeah, short answer is yes, I've solved

658
00:28:41.920 --> 00:28:42.200
that.

659
00:28:42.760 --> 00:28:43.480
Professor Fred Watson: Yeah, good.

660
00:28:43.480 --> 00:28:45.920
All right, well, I'm glad you have. Um, let

661
00:28:45.920 --> 00:28:48.540
us know what you did to overcome this, uh,

662
00:28:48.540 --> 00:28:50.200
infinite energy requirement.

663
00:28:51.480 --> 00:28:53.820
Andrew Dunkley: Yeah, yeah. Uh, there are ways,

664
00:28:54.680 --> 00:28:55.820
um, in theory,

665
00:28:55.980 --> 00:28:58.140
Professor Fred Watson: but, yes, we haven't figured them out yet.

666
00:28:58.680 --> 00:29:00.580
Andrew Dunkley: Um, so did we answer the question? Oh, yeah,

667
00:29:00.580 --> 00:29:01.100
it was no.

668
00:29:01.500 --> 00:29:02.460
Professor Fred Watson: Yes, it's no.

669
00:29:02.940 --> 00:29:04.340
Andrew Dunkley: Yes, it's no, Martin.

670
00:29:04.340 --> 00:29:07.020
Professor Fred Watson: No, but I do like the

671
00:29:07.020 --> 00:29:09.460
idea. I do like the idea of the Peel Gibb.

672
00:29:09.460 --> 00:29:11.460
The Peel Gib. Yes, yes, that's good.

673
00:29:11.460 --> 00:29:14.380
Andrew Dunkley: Very interesting, Martin.

674
00:29:14.580 --> 00:29:16.780
Uh, if you've got questions for us, please go

675
00:29:16.780 --> 00:29:18.020
to our website and send them in

676
00:29:18.020 --> 00:29:20.290
spacenatspodcast.com SpaceNats

677
00:29:21.320 --> 00:29:23.930
are our two URLs. Uh,

678
00:29:23.960 --> 00:29:26.680
we're working on a third URL. It's

679
00:29:26.840 --> 00:29:29.740
peelgib.com. no, probably, um,

680
00:29:30.160 --> 00:29:32.640
not. But, uh, yeah, you can click on the AMA

681
00:29:32.640 --> 00:29:34.480
tab to send us questions. Don't forget to

682
00:29:34.480 --> 00:29:36.120
tell us who you are or where you're from. You

683
00:29:36.120 --> 00:29:38.760
can do that in, uh, audio or text

684
00:29:38.760 --> 00:29:40.440
format and have a look around while you're

685
00:29:40.440 --> 00:29:43.240
there. Don't forget, too, if you will, to

686
00:29:43.240 --> 00:29:45.720
leave reviews, uh, on whatever

687
00:29:45.720 --> 00:29:48.320
podcasting platform you listen to us through

688
00:29:48.320 --> 00:29:50.110
or via or on.

689
00:29:50.680 --> 00:29:52.830
Um, reviews are very, very helpful,

690
00:29:52.830 --> 00:29:55.790
apparently. They, um, they tell people things

691
00:29:55.790 --> 00:29:58.270
about us that we might not want them to know.

692
00:29:58.270 --> 00:30:00.910
But anyway, uh, you, if you would do

693
00:30:01.070 --> 00:30:03.550
us that, ah, kindness, we would be most

694
00:30:03.550 --> 00:30:06.390
appreciative. Uh, and we are just about. We

695
00:30:06.390 --> 00:30:07.750
are done, Fred Watson. Thank you very much.

696
00:30:07.750 --> 00:30:10.460
And you're off for a few weeks because, um,

697
00:30:10.460 --> 00:30:12.470
you've got, you've got some travelling to do

698
00:30:12.470 --> 00:30:14.790
and some people to see and some bills to pay

699
00:30:14.790 --> 00:30:16.640
and, and all that kind of stuff.

700
00:30:17.680 --> 00:30:20.080
Professor Fred Watson: Yes, it's the travel that's taking me away.

701
00:30:20.160 --> 00:30:22.600
Uh, but I'm, um, delighted that you will be

702
00:30:22.600 --> 00:30:25.560
able to keep the flag, uh, waving and keep

703
00:30:25.560 --> 00:30:27.320
the show on the road with our good friend

704
00:30:27.320 --> 00:30:28.240
John T. Horner.

705
00:30:28.240 --> 00:30:30.200
Andrew Dunkley: Yes, John T. Will be joining us from the

706
00:30:30.200 --> 00:30:32.640
University of Southern Queensland, uh, for a

707
00:30:32.640 --> 00:30:34.760
few weeks. Um, Fred Watson, thank you so

708
00:30:34.760 --> 00:30:37.480
much. Uh, happy trails. Um, and, uh, to you

709
00:30:37.480 --> 00:30:38.960
and Marnie. Have a good trip and we'll see

710
00:30:38.960 --> 00:30:39.840
you when you get back.

711
00:30:40.400 --> 00:30:42.360
Professor Fred Watson: Sounds great. Many thanks, Andrew, and talk

712
00:30:42.360 --> 00:30:43.780
to you soon indeed.

713
00:30:43.860 --> 00:30:45.500
Andrew Dunkley: Professor, uh, Fred Watson Watson, astronomer

714
00:30:45.500 --> 00:30:48.020
at large, part of the team here at Space

715
00:30:48.020 --> 00:30:50.260
Nuts, and thanks to Huw in the studio,

716
00:30:51.000 --> 00:30:53.100
uh, who couldn't be with us today. He tried

717
00:30:53.100 --> 00:30:55.460
to peel a gib and nearly cut his finger off.

718
00:30:55.700 --> 00:30:58.060
And from me, Andrew Dunkley, thanks to your

719
00:30:58.060 --> 00:30:59.980
company, we'll see you on the next episode of

720
00:30:59.980 --> 00:31:01.380
Space Nuts. Bye. Bye.

721
00:31:02.660 --> 00:31:04.860
You've been listening to the Space Nuts

722
00:31:04.860 --> 00:31:07.820
podcast, available at

723
00:31:07.820 --> 00:31:09.800
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724
00:31:10.040 --> 00:31:12.800
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725
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726
00:31:14.520 --> 00:31:17.480
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727
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