Some things science can’t explain.
Tide goes in, tide goes out, you can’t explain that.
Hahahaha I’m kidding, you totally can.
What’s up our semidiurnal viewers, Julian here for DNews.
Over the weekend the southern coast of Britain was hit with big waves and some of the highest
tides in 20 years.
What’s causing these huge tides?
And why do we have tides at all, for that matter?
Most people are taught that the moon controls the tides, and that’s pretty much where
their education ends.
While that’s most of what you need to know, it may be a bit confusing when you look closely.
It’s logical that water would be drawn toward the moon because of its gravitational pull,
causing a tidal bulge in that direction.
Weirdly though, a tidal bulge also forms on the opposite side of the planet, and there’s
no secret moon over there.
So what’s going on?
Well you have to remember that the moon’s gravity isn’t just pulling on the water,
it’s pulling on the whole earth too.
Water closest to the moon gets drawn towards it hardest, the Earth gets tugged toward the
moon a little less vigorously, and water on the far side of the earth is pulled much less,
so essentially it’s being left behind and forming its own little lump.
Our moon has a slightly elliptical orbit that varies how far away it is by about 50,000
km each month.
When it’s closest, or in perigee, tides are much more pronounced than when it’s
farthest at apogee.
Another factor affecting tides is land.
If the Earth had no… earth, then the tidal bulges would stay in line with the moon while
the planet and it’s water spinned under them, but luckily for things with legs, we
do have land.
The continents keep the water from freely flowing and it complicates tidal patterns.
Most places get two alternating high and low tides a day.
If the highs and lows are about the same, it’s called semidiurnal.
If they’re different, it’s a mixed semidiurnal pattern.
And if they get one high and one low tide a day, it’s diurnal.
The moon is the biggest factor at work, but the Sun’s getting in on the action too with
solar tides being about half as big as lunar tides.
When the Sun and the moon are aligned twice a month, we experience extreme highs and lows
called spring tides because their powers combine.
When the Sun and moon are at right angles, their gravities smooth out the bulges and
the less extreme differences are called neap tide.
Over the weekend, Britain was on the wrong side of all these factors.
The moon was in perigee, in line with the sun, and the shape of the land along with
stormy weather meant a lot of water was headed for the southern coast.
Bad luck, but it was bound to happen eventually.
At least there’s no vengeful anglophobic curse at work that we can’t explain.
While it’s true there are plenty of things science hasn’t figured out yet, we’ve
got tides pretty much on lock.
So the outside of the planet obviously has a lot going on, but there’s plenty of movement
and shaking under the surface too.
Trace talks about what we’ve figured out in this video:
We’ve got a link in the description if you wanna check out the full episode.
So what are some other natural phenomena you want us to explain?
Let us know in the comments and I’ll see you next time on DNews.