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1:19

Astronomycast, episode 744, Lunar

1:21

Time. Welcome to Astronomycast, your weekly facts-based

1:23

journey through the cosmos, where we help

1:25

you understand not only what we know,

1:27

but how we know what we know.

1:30

I'm Fraser Kane. I'm the publisher of

1:32

the universe today with me, as always,

1:34

is Dr. Pamela Gay, a senior scientist

1:37

for the Planetary Sciences Institute, and the

1:39

director of Cosmquest. Hey, Pamela, how

1:41

you doing? I am doing mostly

1:43

well. I rebooted my computer and

1:45

it lost its brain which caused

1:48

me to lose my brain, but

1:50

I think all brains have now

1:52

been gathered up. I think the

1:54

fact that we have been

1:56

wrestling with audio, software, hardware,

1:58

codecs. gain normalization leveling for

2:00

the entire length of time

2:02

of astronomy cast is hilarious

2:04

and I don't and I

2:06

don't mean that in the

2:08

it's been funny I mean

2:10

it's the enraging we have

2:13

like why is this a

2:15

problem? Why is this happening?

2:17

Why after 18 years? Can

2:19

you not have a microphone

2:21

connected to a computer that

2:23

the sound goes into the

2:25

microphone and is recorded by

2:27

the computer and it's fine?

2:29

Like is that too much

2:31

to ask? It is. So

2:33

this is what we get.

2:35

And this is what you

2:37

get. Which is us having

2:39

hardware, software, audio devices betray

2:41

us. And you, the listener,

2:43

together. The thing that gets

2:46

me at the most stupid

2:48

level is they have now

2:50

added rainbow LEDs to every

2:52

single piece of technology and

2:54

they can get all those

2:56

rainbow LEDs to sink with

2:58

this that and the other

3:00

thing to display brand colors

3:02

to display whatever the heck

3:04

you want light in terms

3:06

of making things look rainbow

3:08

of your choice they got

3:10

it. lighting of green screens

3:12

hard audio audio is impossible

3:14

impossible can't be done wait

3:16

anyone is gonna try to

3:18

do audio you're out of

3:21

your mind it's it is

3:23

just there's no way that

3:25

anyone can record audio from

3:27

a microphone onto a computer

3:29

and have that be saved

3:31

like that's a that's rocket

3:33

science all right what time

3:35

is it okay fine what

3:37

time is it on the

3:39

moon The moon orbits the

3:41

Earth so it doesn't fall

3:43

into a specific time zone.

3:45

Also, there's lower gravity on

3:47

the surface of the moon,

3:49

which changes the rate that

3:51

clocks tick. Well, it's time

3:54

to introduce lunar time. And

3:56

we will talk about it

3:58

a second, but it's time.

4:00

for a break. And we're

4:02

back. All right, so when

4:04

did the, I guess, the

4:06

International Space Exploration Community realize

4:08

that there is a problem

4:10

with thinking about time on

4:13

the moon? So there's always

4:15

been this, yeah, we need

4:17

to worry about this concern

4:19

going on. Like even during

4:21

the Apollo missions, they had

4:23

insane amounts of updating of

4:25

the clocks to make sure

4:28

they could figure out how

4:30

fast they were going in

4:32

feet per second to figure

4:34

out where they were to

4:36

figure out all sorts of

4:38

different things that you don't

4:40

realize require you to know

4:43

when you are. And since

4:45

we didn't stay on the

4:47

movie. it didn't stay a

4:49

problem and it kind of

4:51

fell by the wayside because

4:53

there are a lot of

4:55

problems in space science that

4:58

need solutions and that one

5:00

could just wait. But in

5:02

the early 2020s as it

5:04

became clear that a new

5:06

moon race was on as

5:08

it became clear we were

5:11

and are going back. Some

5:13

of us, some day, some

5:15

time somewhere, some combination. It

5:18

started with ESA being like,

5:20

okay, we need to start

5:22

defining this, we need to

5:24

start figuring this out. And

5:26

so ESA started putting together

5:28

working groups in 2023 and

5:30

not to be outdone. In

5:32

April of 2024, the White

5:34

House put out a memo

5:37

that is no longer available

5:39

on the internet gripe of

5:41

the day. That's really helpful

5:43

for doing research, background research

5:45

on this. Fine, we'll just

5:47

go with what the Europeans

5:49

say. There are so many

5:51

points of information that no

5:53

longer can be found, but

5:55

anyways. Moving on to discuss

5:57

the reality of the situation.

5:59

But so it was realized

6:01

we need to define this

6:03

and the White House in

6:05

April of 2024 said NASA

6:08

you do you coordinate with

6:10

whomever you need to coordinate

6:12

with and by 2026 we

6:14

want a lunar coordinated time.

6:16

This is because everything gets

6:18

gets abbreviated stupid it's called

6:20

coordinated lunar time, and it

6:22

is abbreviated LTC, which is

6:24

consistent with coordinated universal time,

6:26

which is UTC. Okay, so

6:28

we've got lunar coordinated time.

6:30

And what is the proposal

6:32

for lunar coordinated time? What

6:34

will it be? Well, and

6:37

this is where it gets...

6:39

What is the problem that

6:41

we have to solve is

6:43

the starting point? So for

6:45

instance, why is it that

6:47

when astronauts go to the

6:49

moon, they can't just use

6:51

Houston time, which is pretty

6:53

much what the Apollo astronauts

6:55

did. Why can't we in

6:57

general just sink our clocks

6:59

with the clocks on Earth

7:01

and move on with life?

7:03

And the problem's relativity. So

7:06

in the initial... What does

7:08

this need to entail? They

7:10

identified it has to have

7:12

traceability back to UTC It

7:14

has to have accuracy for

7:16

navigation and science and it

7:18

has to be scalable beyond

7:20

the Earth Moon and all

7:22

of this means we need

7:24

to define all the parts

7:26

of the equations That cause

7:28

time to speed up and

7:30

slow down based on the

7:32

size of the gravity well

7:35

you're in and how fast

7:37

you're moving Right. And luckily

7:39

the moon's motion is not

7:41

the dominant factor. We can

7:43

figure it out. It is

7:45

getting... thrown into the calculations,

7:47

it's actually the difference in

7:49

the mass between the moon

7:51

and the earth that creates

7:53

the biggest problems that we

7:55

have to be able to

7:57

correct for. The earth has

7:59

a much bigger mass which

8:01

means that our aging is

8:03

slower compared to people who

8:06

are in orbit around us

8:08

who are aging faster. I

8:10

just forgot the name of

8:12

the movie. Oh, interstellar? Yeah,

8:14

always think of interstellar when

8:16

you're trying to remember who

8:18

ages. Yeah, this is. Yeah,

8:20

that's true. That's for me,

8:22

that's first principles is interstellar.

8:24

Yes. Think about interstellar. He

8:26

spent. a day near a

8:28

supermassive black hole, and when

8:30

he came away from the

8:32

supermassive black hole, his daughter

8:35

had experienced 40 years. Yeah.

8:37

And so, and yeah, that

8:39

clocks run more slowly near

8:41

to higher gravity, gravitational wells.

8:43

And slower clocks means you

8:45

age less, faster clocks mean

8:47

you age more. just for

8:49

people who need to get

8:51

all of that straight in

8:53

their head, which includes people

8:55

like me. Right, but the

8:57

balance that you're mentioning though

8:59

is it's not just... the

9:01

fact that you are near

9:04

a gravitational well, if you

9:06

are farther away from a

9:08

gravitational well, then the clocks

9:10

are going to run more

9:12

quickly for you. But then

9:14

also, there is the speed

9:16

of your spacecraft relative to

9:18

the person who is not.

9:20

And so you've got spacecraft

9:22

that it's going. And then

9:24

it's flipped in reverse. Which

9:26

the ISS hat. So with

9:28

the international space station, they're

9:30

going round and round at

9:32

a zippy pace. slower than

9:35

the people on the surface

9:37

of the planet. Here's where

9:39

you think of Ender's game.

9:41

Right. do everything by movie

9:43

reference. No, that gets perfectly

9:45

appropriate. And then in fact

9:47

there is a perfect balance

9:49

point where the people who

9:51

are in space, and I

9:53

forget the altitude, but there's

9:55

a place where you will

9:57

be the, compared to a

9:59

person on Earth, you're experiencing

10:01

less gravity so your clock

10:04

is clicking more. quickly, but

10:06

also you are moving faster

10:08

until your clock is clicking

10:10

more slowly and there is

10:12

this perfect spot that you

10:14

could be orbiting around the

10:16

earth and you wouldn't experience

10:18

any time drift with those

10:20

two factors. But the point

10:22

that I think, you know,

10:24

back to what you're saying,

10:26

right, that when you're on

10:28

the moon, the moon is

10:30

going around the earth. that

10:33

when you're orbiting around the

10:35

moon you were going at

10:37

a certain velocity relative to

10:39

the earth when you're at

10:41

a lunar halo orbit you're

10:43

going a certain speed when

10:45

you're down on the surface

10:47

of the planet you're experiencing

10:49

different amounts of gravity and

10:51

that the clocks are going

10:53

to tick at a different

10:55

time compared to a person

10:57

on the surface of the

10:59

earth for every single one

11:02

of those conditions yeah and

11:04

and this is where The

11:06

White House in April of

11:08

2024 gave NASA until 2026

11:10

to figure this out. Oh,

11:12

you know what? I want

11:14

to take a break before

11:16

we figure out, like this

11:18

is a cliffhanger. Yeah. They

11:20

were tasked to figure this

11:22

out and what they discovered

11:24

was, and we'll be back

11:26

in the second. And we're

11:28

back. What did they figure

11:30

out? They figured out. They

11:33

being nest the national institutes

11:35

for standards and technology, figured

11:37

out that it is when

11:39

you do all the equations

11:41

and you consider the orbital

11:43

motion of the moon, it

11:45

is the mass difference between

11:47

the moon and the earth

11:49

that dominates the difference in

11:51

the equations of time between

11:53

the two. Not the speed.

11:55

Not the speed it is

11:57

not the speed that is

11:59

the the dominant factor and

12:02

because of this There is

12:04

And here I'm just going

12:06

to read from a paper

12:08

that came out in August

12:10

of 2024 From nest the

12:12

citations authors are Neil Ashby

12:14

and Boonjanath Patla We estimate

12:16

the rate of clocks on

12:18

the moon using a locally

12:20

freely falling reference frame coincident

12:22

with the center of mass

12:24

of the Earth Moon system.

12:26

A clock near the moon's

12:28

selenoid ticks faster than one

12:31

near the Earth's geoid. accumulating

12:33

an extra 56.02 microseconds a

12:35

day, which is a very,

12:37

very fancy way of saying

12:39

that at the surface of

12:41

the moon, compared to the

12:43

surface of the earth, that

12:45

clock is ticking faster. You

12:47

are aging faster on the

12:49

moon, and it's a small

12:51

amount, but it's a amount

12:53

that's going to add up.

12:55

And it's an amount that

12:57

if you don't take it

12:59

into account, once we start

13:02

trying to develop a global

13:04

positioning system for the moon,

13:06

we won't be able to

13:08

do it. And the other

13:10

thing is that as we

13:12

start doing things like building

13:14

telescopes on the moon and

13:16

trying to coordinate data. between

13:18

lunar observations and earth-based observations.

13:20

If we don't take into

13:22

account this difference of 56.02

13:24

microseconds a day, our ability

13:26

to align those data sets

13:28

won't be there. So things

13:31

that are affected if you

13:33

don't take this into account.

13:35

I mean, obviously, pulse. time

13:37

and that's super simple. Where

13:39

things are is going to

13:41

drift over time if you

13:43

don't take it into account

13:45

and you try using the

13:47

exact same global positioning system

13:49

equations that we use for

13:51

our, not the equations are

13:53

the same, if you start

13:55

using the same values that

13:57

we use for our Earth

14:00

system, it's not going to

14:02

work. You're going to have

14:04

to update the chips that

14:06

go in your phone and

14:08

run the calculations to have

14:10

the right constants. One of

14:12

the most amazing things that's

14:14

going to be totally different

14:16

if you don't take this

14:18

into account is our ability

14:20

to do interferometry at radio

14:22

wavelengths. Because right now we

14:24

can have different radio observatories

14:26

all over the world tied

14:29

to their atomic clocks, taking

14:31

observations with those time stamps

14:33

inside the observations. And using

14:35

amazing computer systems, we can

14:37

shift the data around to

14:39

align the incoming radio waves

14:41

to create a radio dish

14:43

that's the size of the

14:45

Earth. Now, when the radio

14:47

waves are coming into the

14:49

moon, we have to account

14:51

for the difference in distance

14:53

to the lunar dish and

14:55

the Earth dish. That's one

14:57

thing that has to do

15:00

in the process of aligning

15:02

the data. But then we

15:04

also have to either stretch

15:06

or compress. And in this

15:08

case, it turns out if

15:10

time is going faster, you

15:12

have to stretch the data

15:14

out to get the time

15:16

that's passing to be the

15:18

same for the data collected

15:20

on the moon and the

15:22

data collected on the Earth.

15:24

And that's just wild to

15:26

me to think about. Time

15:29

is going to affect things

15:31

at that level. Your hair

15:33

again. Okay. for. I'm apparently

15:35

going to use a booklet

15:37

pulled back my hair. Perfect.

15:39

Rich, feel free to leave

15:41

this in so our audience

15:43

knows what chaos is occurring

15:45

when they get the audio

15:47

file. I'm very sorry everyone.

15:49

I am going to have

15:51

some housework done next week.

15:53

to seal the walls of

15:55

my studio. And so I

15:58

haven't set my good mic

16:00

back up after getting a

16:02

computer. Right. Because I'm just

16:04

going to have to move

16:06

everything anyways. Yeah. So this

16:08

is a high quality mic.

16:10

It's just subject to long

16:12

hair. All right. We're going

16:14

to continue this conversation, but

16:16

it is time for another

16:18

break. And we're back. Right.

16:20

So it's kind of fascinating

16:22

to think. Like the nitty

16:24

greedy, greedy, people are like,

16:26

oh, I want us to

16:29

be living on Mars. We

16:31

want to have a future

16:33

solar system spanning civilization. But

16:35

you can imagine somebody, you

16:37

know, now detail has to

16:39

show up and sort of

16:41

join the conversation. And can

16:43

you imagine taking that concept

16:45

to the next level where

16:47

like, oh, okay. What does

16:49

it mean to be out

16:51

of the L2 Lagrange point?

16:53

What does it mean to

16:55

be on Mars, on the

16:58

surface of Mars, on Phobos?

17:00

What time does Parker Solar

17:02

Probe experience compared to the

17:04

time that is experienced by

17:06

us here on Earth? And

17:08

that a future solar system

17:10

spanning civilization, especially one that's

17:12

attempting to conduct science operations,

17:14

trying to synchronize... global positioning

17:16

systems and communication systems to

17:18

manage the time delays is

17:20

going to just have a

17:22

headache of the nth degree.

17:24

It's mind bending and yet

17:27

you can see Yeah, if

17:29

you don't account for that

17:31

time dilation, then you are

17:33

not going to be able

17:35

to align the measurements made

17:37

by a interferometer that's operating

17:39

between the Earth and the

17:41

moon. You are not going

17:43

to have an accurate timekeeping

17:45

of when events happened so

17:47

that you can make sure

17:49

that the packets are arranged

17:51

in the right way to...

17:53

put together a communication system.

17:56

Like all of these are

17:58

actually going to be a

18:00

big enough problem that the

18:02

European Space Agency is assigning

18:04

a group, NASA is assigning

18:06

a group, and they're going

18:08

to come together with some

18:10

future global standards that then

18:12

everybody, including the Chinese, probably,

18:14

will have to work with.

18:16

It's crazy. It's kind of

18:18

humbling. It's not linear. I

18:20

mean, this is the crazy

18:22

thing. things are on elliptical

18:24

orbits, the offset in time

18:27

varies with time. So you

18:29

have to basically define this

18:31

is the moment at which

18:33

clocks are synced. And now

18:35

to figure out when this

18:37

place is, you have to

18:39

take into account the overall

18:41

offset due to mass, which

18:43

is a standard. You have

18:45

to, we assume the mass

18:47

of the moon will remain

18:49

constant, but it's a good

18:51

idea. But then you also

18:53

have to take into account

18:56

that, yes, there is a

18:58

subtle difference due to orbital

19:00

speed that can mostly be

19:02

ignored, but not completely be

19:04

ignored. And the orbit's an

19:06

ellipse. So the difference in

19:08

the rate of time passage...

19:10

varies as a function of

19:12

where you are in your

19:14

orbit and the rate you're

19:16

going in your orbit. And

19:18

this is something that you

19:20

have to take into account

19:22

for every world, for every

19:25

different mass object. And you

19:27

have to layer on the

19:29

I'm on Phobos, which means

19:31

I'm in motion due to

19:33

going around Mars, but I'm

19:35

also in motion due to

19:37

overall motion going around the

19:39

sun. And then you have

19:41

to take into account the

19:43

fact that when you're looking

19:45

at the signals, the time

19:47

that it takes, each successive

19:49

wave getting to you, is

19:51

going to be different. So

19:53

there's a Doppler shifting of

19:56

the signal. Now that doesn't

19:58

affect the rate of time,

20:00

that affects the rate of

20:02

incoming information, but all of

20:04

these things have to be

20:06

taken into account as we

20:08

send and receive information about

20:10

the universe around us and

20:12

about our world and the

20:14

world we're trying to communicate

20:16

with. In trying to define

20:18

time, poor Asby and Patla

20:20

in their paper from Nest,

20:22

they... set out to look

20:25

at not just how time

20:27

passes on the moon, but

20:29

they also considered the various

20:31

Earth-moon Lagrange points as as

20:33

places we also need to

20:35

take into consideration Because this

20:37

is where we're looking to

20:39

put things like the lunar

20:41

gateway This is where we're

20:43

looking to put communication satellites

20:45

to communicate with the far

20:47

side of the moon All

20:49

of these different places have

20:51

different passages of time And

20:54

it's interesting, if you go

20:56

back to that definition that

20:58

you provided, it's that you

21:00

were assuming a soliton that

21:02

is in orbit around the

21:04

moon or a soliton, and

21:06

that's interesting because that's very

21:08

similar to the way the

21:10

astronomical unit is described. Like

21:12

the astronomical unit, the rough

21:14

version is it's the average

21:16

distance from the sun. to

21:18

the earth. But in fact,

21:20

that is inaccurate because the

21:23

earth is pulling on the

21:25

sun and that's causing a

21:27

wobble on the sun's position.

21:29

And so the actually the

21:31

distance from the sun to

21:33

the earth changes not only

21:35

because the earth is... following

21:37

an elliptical path around the

21:39

sun, but also the fact

21:41

that the earth, the sun

21:43

is wobbling at tens of

21:45

centimeters per second, forward and

21:47

backward, thanks to the gravitational

21:49

pull of the earth. It

21:51

is, you know, they're both

21:54

orbiting around the Barry Center,

21:56

too. And Jupiter, Jupiter is

21:58

the dominant factor. Yeah, no,

22:00

for sure, for sure. But,

22:02

and so when you measure

22:04

an astronomical unit, you are

22:06

imagining if you're going to

22:08

follow NIST or whatever, it's

22:10

a soliton orbiting the sun.

22:12

because that has no mass

22:14

and that is theoretically not

22:16

pulling back and forth on

22:18

the sun. And so the

22:20

reality is inaccurate by a

22:23

certain wide margin, not just

22:25

because of the move in

22:27

the earth, but also the

22:29

move in the earth causes

22:31

to the sun. And so

22:33

when you're considering this, you

22:35

know, they very specifically said

22:37

we're going to consider us

22:39

all the time, because if

22:41

we consider something that has

22:43

mass, then that is going

22:45

to affect the, you know,

22:47

the positions of things and

22:49

just make things even more

22:52

complicated. It's, you know, a

22:54

lot of the times we

22:56

have these conversations on astronomy

22:58

cast about things that are

23:00

theoretically possible, but practically not

23:02

relevant. Like, could we look

23:04

backwards in time by looking

23:06

at the light that was

23:08

going around a black hole

23:10

to see a time in

23:12

the past? Yeah, theoretically, photons

23:14

are making the journey from

23:16

the earth out to a

23:18

black hole, they're coming around

23:20

the back side of the

23:23

black hole, and they're making

23:25

their way back to us.

23:27

Theoretically, but practically, no. But

23:29

in this case... slices of

23:31

time that are so small

23:33

are actually practical, having a

23:35

practical implication to the way

23:37

we will conduct our exploration,

23:39

to the point that people

23:41

could die if you get

23:43

this time wrong. And so

23:45

we have to take into

23:47

account and yet it is

23:49

mind-bendingly complicated. Like I don't

23:52

think anybody will ever go,

23:54

oh yeah, we lost 60

23:56

microseconds today like you do.

23:58

Well, and then you have

24:00

to like... the fact that

24:02

we have stuff like leap

24:04

seconds here on the surface

24:06

of the Earth. Yeah. And

24:08

so when Earth leap seconds,

24:10

what do you do with

24:12

the rest of the solar

24:14

system's time? Because that leap

24:16

second is aligning us with

24:18

our world's orbit and rotation

24:21

relative to the Sun and

24:23

stars. Other worlds

24:25

aren't going to have the exact

24:27

same needs for realignment. And there's

24:30

stupid stuff that changes on the

24:32

surface of our planet, like when

24:34

China put together their, what is

24:37

it, five gorgeous dam? Three gorgeous

24:39

dam. Three gorgeous dam. That changed

24:41

the rotation rate of our planet

24:44

because the moment of inertia changed.

24:46

Yeah. And we have to periodically

24:48

upgrade. The rotation of the Earth

24:51

is slowing down because the moon

24:53

is moving away from us. And

24:55

so, and I forget the exact

24:58

number, like I just noticed this

25:00

and I'm sort of incorporating it,

25:03

but it's like on the order

25:05

of tens of microseconds per day

25:07

per century is being caused by

25:10

this slow, you know, the Earth's

25:12

rate of turning is slowing down.

25:14

in a rate that is measurable.

25:17

And I think you're exactly right,

25:19

you know, when we deal with

25:21

leap seconds, or it's this, you

25:24

know, it was fine, and now

25:26

it's not fine. Now we have

25:28

to go back a whole second.

25:31

Right. Does everybody across the solar

25:33

system? Or do we switch to

25:35

there is no such thing as

25:38

leap seconds? There's no such thing

25:40

as years anymore. You just accurately

25:42

measure. Yeah, star dates. Yeah, exactly.

25:45

Is this start dates? I think

25:47

it starts to become that. We

25:50

have Julian dates that we use

25:52

in astronomy that go back to

25:54

a set time and get calculated

25:57

forward and it gets messy. So

25:59

yeah. So what is the, I

26:01

don't know the way it works

26:04

in Star Trek. Where does the

26:06

star date originate? I don't, I

26:08

don't know. And I wonder, do

26:11

you know this? I'm realizing, so

26:13

with Earth we have one moon

26:15

that creates enough havoc for us

26:18

and because it is moving away

26:20

from us because it's orbital rate

26:22

around the Earth. is longer than

26:25

the length of our day, it

26:27

moves out. Now Mars has two

26:30

moons, one that has an orbital

26:32

period shorter than its day and

26:34

one that has an orbital period

26:37

longer than its day. Which one

26:39

dominates? What's its rotation doing? I

26:41

think it's... I think Phobos is

26:44

dominating, so it's speeding up its

26:46

rotation until Phobos is destroyed, and

26:48

then it'll be damos that dominates

26:51

since it's back down again. Yeah,

26:53

so not our problem at least.

26:55

No, well, future Mars problem. Yeah,

26:58

but yeah, yeah, it still just

27:00

kind of blows my mind that

27:02

that our technology is so accurate.

27:05

We deal with these wavelengths that

27:07

are nanometers across our technologies is

27:09

depending on this kind of stuff

27:12

and we're getting to this place

27:14

in our in our sort of

27:17

world our advancement that these are

27:19

issues that we have to take

27:21

into consideration or things break right

27:24

ships go off course if you

27:26

don't take into account relativistic issues

27:28

you don't take it just time

27:31

to issue into account for the

27:33

GPS satellite systems and now ships

27:35

will go off or off track

27:38

when they're trying to go to

27:40

the moon because we're not getting

27:42

the time right or we will

27:45

yeah yeah and so you're gonna

27:47

have a clock on board that

27:49

is adjusting Based on that and

27:52

then you think about say Like

27:54

the you know, I am legion

27:57

we're about we're a legion I

27:59

am Bob series where he has

28:01

community between different versions of Bob

28:04

and they are moving at different

28:06

rates of relative to the speed

28:08

of light and they have to

28:11

experience different amounts of time dilation

28:13

as they try to talk to

28:15

each other and then they have

28:18

ways of accounting for that where

28:20

where one version will just wait

28:22

around or do other things always

28:25

waiting for the frames to come

28:27

in for another version of himself

28:29

and You know, I guess it's

28:32

like, you know, nice problems to

28:34

have that we're so advanced that

28:36

we now have to take into

28:39

account relativeistic facts when we attempt

28:41

to communicate. I think it's great.

28:44

And this is where ultimately Pulsars

28:46

will form one of our most

28:48

important coordinate systems. We're going to

28:51

rely on how time passes relative

28:53

to those objects. And this is

28:55

one of those things that the

28:58

Foundation series, which I need to

29:00

go back and rewatch because I

29:02

haven't watched this second season yet.

29:05

The Foundation series really hits on

29:07

this, looking at how time passes

29:09

as you travel and how you

29:12

measure your place. Well, I think

29:14

we should cover the, for Pulsar

29:16

timing as a future episode and

29:19

talk both about the Pulsar timing

29:21

network as a, you know, as

29:24

a gravitational, we talked about gravitational

29:26

waves, but also as a potential

29:28

wave of timing. There's some interesting

29:31

work on that, so that's a

29:33

future show. Could be next week.

29:35

Maybe, sure. Thank you, Fraser, and

29:38

thank you so much to our

29:40

patrons who allow us to have

29:42

a team that usually cleans up

29:45

what we can do, although I

29:47

don't think Rich is going to

29:49

be able to correct what my

29:52

hair did to this episode's audio,

29:54

I am so sorry everyone. This

29:56

week, in particular, we would like

29:59

to thank Ellen Gross, Alex Cohen,

30:01

Andrew Stevenson, Bebop Apocalypse, Brett Mormon,

30:03

Camirasian Daniel Looseley, Danie MacLitchie, David

30:06

Gates, Dastrina, Dr. Woe, Dr. Jeff

30:08

Collins, Ed, Elliot Walker, Father Prax,

30:11

Frank Stewart, G. Caleb Sexton, Gerard

30:13

Schweitzer. Gordon Lewis, Grigory Singleton, Jarvis

30:15

Earl, Jeff Hunamorder, Jeff Wilson, John

30:18

Drake, Keith Murray, Kelly and David

30:20

Parker, Kimberly Rike, Christian Golding, Laura

30:22

Kettleson, Lee Harborn, Mark Phillips, Matthew

30:25

Horseman, Mathias Hayden, Michael Prachada. Mike

30:27

Dog. Nila. Noah Albertson, Redbar, is

30:29

watching. Share some Simeon Torfison. Ziggy

30:32

Kamler, Stephen Vite, The Big Squish

30:34

Squash, The Lonely Sandperson, Travis C.

30:36

Porco, Adam Anise Brown, Adam Moore,

30:39

Arctic Fox, Benjamin Mueller, Bob Zatski,

30:41

Buzz, Parsack. I went into next

30:43

week's names. Some of you will

30:46

get thanked twice. Thank you all

30:48

so much for joining us and

30:51

making what we do possible. Thanks

30:53

everyone and we will see you

30:55

next week. Bye-bye. Astronomycast

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is a joint product of Universe

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