Moon Drift

Based on measurements made over the years by the Lunar Laser Ranging Experiment (LLRE), the Moon is slowly drifting away from the Earth..
at the rate of 3.82 +/- .07 centimeters every year!

However, what if the Moon isn’t moving away from us or at least not as quickly as we might think? What if the speed of light is not Constant but is changing over time? Next year a new experiment hopes to shine some light on the speed of light and help determine whether the speed is constant or is actually slowing down. According to a new theory by Louise Riofio, the speed of light is getting slower at a rate of 1 centimeter per second each year.

Please keep in mind that this is a teeny tiny amount shorter each year. Since light can travel at nearly 300,000 km/s, a centimeter less is hardly noticeable. If true and because this a cumulative effect, this change will be become more noticeable over time. In ten years it’d be 10 cm less distance traveled in a second, in a hundred years it’d be 100 cm less / s. This also indicates that the speed of light might have been much faster in our past.

Moon drift
Photo of the Earth’s Moon taken from my backyard on April 13th 2019 as it drifts away from us

If you shine a laser beam at the Moon and bounce it off the mirror you can figure out how long it takes for the light to get there and back. Spoiler: it’s less than 3 seconds.

The distance to the Moon from earth is roughly 384,400 km
[384,400,000 meters away from us] and the speed of light is 299 792 458 m / s

The time it takes for light to travel to the moon is

384,400,000 m / 299,792,458 m  = 1.2822203.. seconds

Now keep in mind that I’m using a single number for the distance to the moon and that the moon actually gets closer to earth and sometimes further away. At times as close as 356,761 km or it can be as far as 406,555 km [*see moon distance time table below]

It takes about 1.3 seconds for light to get to the Moon bounce off the mirror and then come back to us so that’s another 1.3 s for the return trip. Unfortunately, the distance to the Moon changes based on its orbit. So the time it takes depends on when you measure it and from where on earth you measure it.

Closest: ~356,761 km divided by the distance light travels in one second = 1.1900266.. seconds
Furthest: ~406,555 km divided by the distance light travels in one second = 1.35612150.. seconds

I’m not sure about the precision on this, since I’m rounding the numbers to start with, the precision isn’t really the important part, as much as to know that there’s a range of time that light can take to reach the Moon which is between ~1.19 to ~1.35 seconds.

Despite the fact that the distance changes depending on where the Moon is in its orbit, on average these measurements indicate that the distance to the moon is increasing every year by 3.8 cm but what if the speed of light is not constant? What if the moon isn’t getting further away but the speed of light is actually slowing down? Is this possible and how could we tell?

If the Moon is moving away from earth at this speed then it would have been much closer to us not that long ago assuming that the rate of change is constant and has always been constant. In fact, the Moon should have been too close much too recently for current theories of the age of the Moon. Also we do not know at this point if this is cyclical, will it slow down in ten years or a thousand years?

Only time will tell

Upcoming experiments on the International Space Station may demonstrate whether or not the speed of light is always the same over time. The current hypothesis is that light is in fact getting slower every year, but the experimental data will hopefully tell us whether it’s the same, slowing down or speeding up. The suspicion is that it’s a rate of 1 cm / s per year but what if it’s more? What if it’s less? What effect will that have on the Moon drift rate?

Let’s take a look

If the rate of change for the speed of light turns out to be: 1 cm / s per year

Then this would mean that the apparent moon drift of 3.82 cm each year is actually..

If I understand this correctly, since the time it takes for light to reach the Moon from earth is 1.2822203 seconds (when the Moon is 384,400 km from us) and if the speed of light is slowing down by 1 cm / s then shouldn’t the effect be 1.2822203 cm? So, 3.82 cm subtract 1.28 cm I get 2.54 cm of actual Moon drift. Still on its way but not as quickly as we thought.

If it turns out that the speed of light is slowing down at a greater rate,
let’s say 3 cm / s per year then..

Distance to the Moon in light seconds: 1.2822203 x 3 cm = 3.8466.. cm then the Moon would no longer be drifting away but is in fact drifting towards us!

I might be missing something obvious in these sloppy math estimates and if I am please let me know. For one, I expect that it’s very very unlikely to be a rate of 3 cm/s per year. That would have huge implications for the entire Universe! It makes me wonder if this change in speed is everywhere or if it’s a local phenomena?

When we look upon the Moon today we always see the same side but if we’re standing on the Moon looking back at Earth, the Earth spins and reveals all.

If the speed of light is constant over time (as most of us have thought it to be) then the Moon’s orbit really is increasing at the speed we observe, at least for the time being. At this rate, in a about 50 billion years from now, a month will be 47 days long as the moon locks into the same side of Earth. The Moon will see the Earth spin more and more slowly until it finally stops and shows only one side to the Moon. It is believed that at this point the Moon will stop moving away from Earth as the tidal forces and gravitational drag that caused the drift will have stopped.

If on the other hand what if the speed of light is speeding up by 1 cm / s per year? Then the Moon is going bye bye. It’d be flying away from us at the speed of 4.8 cm each year. Not good, mind you, probably nothing to worry about for few billion years.

One last note, if it turns out that the speed of light is slowing down exactly the same speed that the Moon is drifting away from us, well, that would be super freaky!


Is the Moon moving away from us and when was this discovered?

GM=tc^3 Adventures in Space/Time

Moon distance time table

Apollo Laser Ranging Experiments Yield Results August, 1994

Measuring the distance to the moon with radio waves instead of lasers

Do you have an irrational fear of clicking on links?

At work there’s a policy where we should not click on links in our emails.  However, we still click when we’re confident that it is safe to do so because I know it’s from my sister or from my best friend.  It might not be an ‘appropriate’ link for my current environment, but chances are the link they send is something they know about and they’re sharing and you can have confidence in knowing it’s safe to click.

It’s very unlikely that a friend would send you an unsafe link on purpose, but there’s always a remote chance that your friend loses control of his email and then you’re smart to think twice about clicking on it.

So what is so unsafe with links?

Why worry about such things?  Should I really be that concerned about it?
One of the concerns, as I understand, is that if you click on a link in your email that link will open up a file on a web server.  Doing this *might* identify you to the server as a ‘real person who reads the email’ and then they’ll send you more email spam.  Another concern is that the link you open might not be the ‘real’ website but a fake website that is pretending to be something else.  If you fall for it and log in with your user name and password then you might be giving that information to the wrong person.

How can you tell what is real and what is fake?

Simple, if you’re concerned about the link then you should instead go to your browser and type the url for the site directly into the top of the browser in the url field.  Or you can also search for the site on google and then look for the correct website.

As an example, if you’re looking for “wikipedia” you should see as the google  search result.  The important part is

If you’re on this site and want to know it is the ‘real’ deal, then look at the url at the top and you can tell it’s the authentic site because the url is
Not, anything else.  (you might only see the part)  The stuff after the [.com/] are things on this site that are under my control.  But once I write something anyone could then copy it if they wished to and paste it on their computer or on another website.  Comments that people make are their own and I might not agree with them but I do try to make sure no one is saying anything mean spirited.

The url is a good indicator as to whether a website is ‘fake’ and/or ‘unsafe’.  To find out more, you can read more at this site:

How I can identify phishing websites.

The links on this site go to other websites but I do not track anyone other than as stated in this website’s privacy policy.  This link goes to my privacy policy page.

Now, there is good reason to hesitate when you click on links but please don’t let that fear hide the interweb from you.  If you get lost close your browser and start again. 😉

A link to google search: ‘Do you have an irrational fear of clicking on links?’
Note that the first part is

Copy paste if you want to open it in your browser directly.
expressed as link to the search.

This an example of a link pointing to a specific search on google. [this link will search for  ‘Joberrr’ on Google]

What is the best background noise for work?

About 15 years ago I worked in an office with a white noise generator.  It kept an otherwise loud environment filled with many lively coversations to a dull roar.  It worked rather well, to a point.  Pretty quickly your brain tunes out the white noise, it just becomes part of the environment and makes it easier to concentrate on your work. I’m sure some noise generators are better than others.

Noise Generation

However, a white noise generator can also be very irritating for some people.  I’ve read that it can possibly even increase your stress level rather than do what it is supposed to do which is to provide a peaceful and seemingly quiet work space.
My current office has a rather loud ventilation system that blocks out quite a bit of the distracting conversations in the adjacent cubicles.  When the fans turn off, there’s a sudden deafening silence.  It feels strange without the white noise of the ventilation system.  It turns off so rarely, otherwise it runs continuously all day, every day, winter or summer.  Without the vents on, everything and everyone seems so much louder, so much more noticeable.
If I had to block out the surrounding office noise by wearing headphones, I would not choose to listen to most of the ‘ambient’ noise generator apps that I’ve tried.  There are some exceptions of course, but typically for me,  10 to 15 minutes is all I can take of ambient music, after that my skin starts to crawl. I find that listening to music with vocals can be equally distracting.  If I’m reading or otherwise trying to concentrate, Jazz or Classical music would be a good choice.  I tested my album to see if I can actually work while listening to it.  I have to say it really depends on what I’m working on.  If it’s a mostly visual task like working with Photoshop then it passes the test quite nicely.  Ultimately, not having to wear headphones to block out the noise at work would be best.
In my opinion, the best background noise for work would be the natural sounds you hear sitting in the woods among the trees, the birds and the insects.   Far away from the fax machine, the paper shredder and the sound of the ventilation system. Somehow, I don’t think listening to a recording of ‘sounds of the woods’ will help my work environment.  If only we could open a window in our office.  Oh imagine the nuisance of that! There would be no end to it, some of us would want the window to always be open, others for it to always be shut.

So it goes.

You Silly Wabbit!

Why is track 12  named “:(){ :|:& };:”?

That line of special characters consisting of some colons, a semi-colon, parentheses, brackets, braces and an ampersand is what is known as a fork bomb or wabbit.  This tiny bit of code will replicate itself like a couple of rabbits until it uses up all of your computer resources and your machine crashes.  You would need to type this into a terminal window for it to execute (not a good idea).  To read more details on how it works check out this Wiki article.
When I was creating track 12, the sound from the ‘retro space lead’ synthesizer I was using made me think of a recursive loop.  That is when the fork bomb name came to mind.
Interestingly, when this title was uploaded to the iTunes store, certain characters were stripped out and you end up with only this line: [::&];:  Typing this into a terminal window will give you the following response: ‘-bash: [::: command not found. In other words, it’s completely harmless.
There are some variations between music stores, the Google Play store shows the title as () [:|:&];:  I’m guessing the programmers added a rule that you can’t start the name of your song with a colon (:) because that might be confused with the same character that is  sometimes used in the path name to denote a directory.
At Amazon you end up with :() [:|:&];:  Different software with different rules on how to handle special characters but they all do pretty much the same thing, protect their data from getting messed up.  It seems for whatever reason that all stores swapped the squiggly braces ‘{}’ for brackets ‘[]’.

Where can I find out more information about punctuation marks?

Please try the