Arecibo observatory is an iconic scientific instrument
and arguably one of the most recognizable around the world
and sadly on the 1st of December we lost this key asset when it collapsed as this collapse
was preempted no one was injured from this event and luckily for us there was many cameras set up
on it so we're able to get a bird's-eye view of this collapse in detail as it occurred
before we analyze this collapse let's rewind a little bit and find out a little bit about
Arecibo observatory what makes it unique and how it was constructed
Arecibo was the largest radio telescope up until 1997. it was only surpassed recently by the fast
observatory in china which is almost double the size arecibo's biggest discovery was the
fact it was first to detect gravitational waves through observing a binary pulsar system it was
also the largest radar telescope in the world so what this gave us the ability to do was bounce
radar waves off distant objects such as venus and mercury and determine the rotational spin
radar is also very useful at determining how far an object is away observing near-earth objects
such as asteroids from telescope were not able to actually determine the distance of that object
releasing enough detail to determine the orbit of that object years in advance through radar
and bouncing it off such objects we're able to give enough insight to the distance of that
object to determine many years in advance to see whether it's at risk of crashing into the earth
the next best radio telescope is actually 20 times less accurate so due to the inverse square rule
which states that the further a radio signal travels the strength is reduced by squared so
roughly as it needs to go there once and come back the strength of such radio waves is reduced by
about 16 times so it only gives us about twice the distance of accuracy that is still a long way so
it's a big loss to the scientific community determining those near earth or asteroids
now you may not recognize aristotle reference scientific findings but maybe it's featuring
in the james bond film goldeneye where their final shots were shot at this location due to its unique
features ironically they actually destroyed it inside the film the construction area received was
completed in the 1960s as location was chosen drew its unique geographic features
mainly the sinkhole that they built the dish into they were to build the three masts around peaks
around the sinkhole to allow them to string up and hold the scientific instruments over the dish in
august this year worrying signs started the show at eric when one of the cables slipped out of the
guidelines yes this was concerning at the time but not highly worrying as it was fire the other
cables supporting the central dome system plans were drawn up by engineers and they are currently
shipping out replacement cables to fix the cable that's actually slipped down however on the 5th
of november one of the primary cables snapped now this cable snapped at about 60 of the design load
now this is highly concerning for two reasons firstly the determined strength of the remaining
cables is unknown as this cable snapped at such a low load and also now that we only
have four cables left in this system the load increase on the remaining cables was up to 50
more which makes it even highly concerning as we do not know the strength of the remaining cables
as why did that cable snap at a lower strength was it just a one-off
was it damaged at the time or do the remaining cables had the same limiting factor in string
after this cable snapped their plan efforts were put on hold as it was deemed to be a too
risky adventure to put people up on that dish that may collapse at any time and the fact that
they're actually hanging new cables there would be additional weight in the system that may be the
stone that tipped it over the edge now there were some pretty far-fetched ideas of hanging people
from helicopters and such as they repaired the dish but inevitably it was determined to be a too
risky adventure so they eventually drew up plans to try and demolish the dish they never got around
to this as on the 1st of december the events that we saw earlier took place now let's analyze this
in detail before we get into the analysis don't forget to smash that like button it helps get it
out to more people and i'll be highly grateful now let's get into it right now we're on that faithful
day of the collapse of aerosol and we're just seconds away from the event at a gopro position
at the observation point of the collapse tower luckily for us at the time of this event there was
also a drone at the critical tower observing the cables obviously trying to plan out the demolition
of this tower right when the event occurred as you can see at the time of this event the drone was
really close to the critical tower observing the cables and what was actually happening there
luckily for us we're able to get a really close view of the failure of this tower as
it happens really quickly to get your bearing points of where we currently are the drone is
looking at the tower with its back facing the dish so essentially it's in between the tower
and the dish itself so we're looking back away from the dish at this point so i've slowed down
the speed of this event to at least 10 percent of the original speed to give us some sort of context
of how this event occurred and we can see that it's not just a single failure
but a cascade value with one after another failing before the whole thing comes down
now the reason why i've slowed down this footage so much is the speed at which the failure occurs
even at 10 percent you can see it still happens really quickly so it's a really quick succession
of balances that occur in a short period of time now if we are looking at those cables
you can see some of them are painted and some of them not the ones that are not painted but
due to the internal cables snapping essentially flecking the paint off so it means they're damaged
so the paint is there for two reasons so it's there not only to protect it durability wise
but it also helps to detect when you have little bits of value in your cables quite quickly
and it'll be highly evident so keep your eye on that cable with the strap around it the one at the
bottom that is the first cable to snap and you'll see flecks of paint leaking off it quite quickly
and now this is the point where the first of the remaining cable snaps
so now there is only three cables supporting the main dish so what this is now done is essentially
doubled the remaining load in the remaining three cables now this load is just not static
there's dynamic actions occurring as power is rocking backwards and forwards these dynamic
actions increase the load even further so it's more than double the load in the remaining cables
so this quickly overloads the remaining cables so let's keep an eye on them as this third cable
breaks keep your eye on the far cable as well as that one will snap really quickly after that
third cable breaks so now there's only two cables remaining and now if we keep an eye on that
closest cable it's currently in good condition you can see that there is no paint currently flicked
off it so it's currently in its prime condition however as now there is only two cables remaining
this cable is now highly overloaded and as you can see it will unravel itself very quickly
as the flexor panes keeps coming off you essentially see it unwind itself
and then this is the point where the towel lets go
so now we only have one cable remaining which is way too much for this cable
to hold and you can see the tower is now aggressively rocking backwards and forwards
as now the dish has essentially gone into freefall there's a load on the remaining cable overloads
it very quickly as this column is now growing from what is essentially a compression force
into a bending action let's go back to the gopro to see as the tail comes down now if
we're looking at the main dish you can see there is essentially two structures on them
you have the primary structure that is supported by the cables and the instrument equipment is
essentially hanging underneath on rails so as it comes swinging down the main instrument equipment
will be detached and fall off earlier prior to the primary structure hitting the dome as it comes
down as well the two primary cables are swinging to the catwalk essentially smashing that apart
now if we go back to that critical tower the original one that failed occurred you essentially
will see it snap off at mid high this is due to the column originally acting in
primary compression force it has now has lost the tension of course from
the instrument recruitment there's now turned into a bending action so this critical point
which is the weakest point as you can see it's stepping up the tower so at the bottom of the
thinnest point of the tower is where it would be most critical is where the failure occurs
this also happens to the remaining two towers which you'll say will also come tumbling down
now let's move back to that drone as i'll turn around to watch the dome come crashing down
and we'll see the remaining damage that occurs to a receiver
as these cables are not small they are very heavy and required major damage then it was underneath
them the damage not only occurred to the dish itself and the primary towers but also there
was damage occurring to the remaining structures around it as well also one of the portions of
the columns also smashed into one of the access roads damaging it so there'll be quite a lot of
work to get this dish operational again hopefully there is drive from the international community to
bring this iconic instrument back online it is had some unique binding to the scientific community
and it would still be valuable now and well into the future as you can see we had a
unique observation point of this collapse and the cascading events that led up to the final demise
of arecibo and i hope you enjoyed this episode and if you did as i was saying earlier don't forget
to smash that like button it helps me out greatly if you haven't subscribed at this point
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look forward to seeing you next week where my episode will likely be on next wednesday bye