WTC-7 Mysteries FINALLY Solved.

www.abovetopsecret.com...
I forgot to provide the link to my thread there.
My post 1 is the E.P. Heidner links one, in this ATS thread titled :
The SINGLE MOST IMPORTANT ANALYSIS of the events of 9/11.
www.abovetopsecret.com...

Collateral Damage-part 1
Collateral Damage-part 2
Document: Fifty Years of the Deep State - WikiSpooks

The substandard steel and sloppy fireproofing is indeed an interesting side of the 9/11 story.

There are however many more sides to observe.
Like _BoneZ_ already hinted at, the explosive squibs spitting/blowing out of 3 to 4 windows per much lower situated floors while the collapse front was still far higher up, racing downwards.
Pteridine said gravitational speed exceeds demolition speed, and I agree with him.

But I agree only with him for speeds observed AFTER the first explosive charges were lit on the top-impacted floors, that were just strafed by the impacting planes their wing tips. After that, we watched a fast gravitational collapse developing, instigated by the three first floors that were demolished by some very powerful explosives, which I assume were of the thermobaric or fuel-air kind, since from that high up, their sounds were still in the very low sound regions. Standard cutter charges are much higher pitched and by far not so loud, especially not when detonated in still intact floors with all window glass also still intact.

Then the whole top tower part worth of floors above these three blown out first detonated floors fell the height of 3 floors and were from then on, unstoppable. But to be sure of a rapid progression all the way down, without a surely not wanted halt somewhere midway, the planners chose to lit some more charges at some far further down floors, to break the back of the essential corner core columns there. Which we saw as those peculiar squibs bursting out of a few adjacent windows, 20 or so floors lower :



One may assume that on these first 2 or 3 demolished top floors all the fireproofing was still in place and would have protected the vertical steel columns and the horizontal steel beams for more than 2 hrs, since they were rated for at least that long, if those floors failed from fires ALONE. They were not rated for the then standard 4 hrs by the way, later mayor Giuliani took care of that with a staff of lawyers, they forced the City of NY to change these 4 hrs retention time to 2 hrs, so constructing the Twin Towers could proceed after a building inspector stopped all work because of non-standard, too short lived, fire proofing.
Both towers collapsed thus, far too early.

Especially when one still insists on no demolition and assumes that the steel on those first collapsing floors was only fatally compromised by the freshly lit fires there.
Which fires however burned no more than 15 minutes at most there, after been lit by lower fires creeping upwards.
Just 15 minutes max before these 2 or 3 concrete floors, just above the top plane-impacted ones and all their supporting steel that was more than 95 % still fully intact, suddenly blew outwards, and failed totally, as evidenced by the huge ring shaped whitish smoke and dust clouds emanating from a few floors (2 or 3) at once, on all 4 sides of these first failing floors.
Where it was impossible to have bend, warped or otherwise compromised core columns present, already that fast, created by such 15 minutes existing fires.

Quite some readers here support the false idea that a natural gravitational collapse initiation of thick steel members by fire alone, automatically leads to global collapse -- an assumption that runs counter to all experience and lacks experimental verification.
All natural collapses are chaotic by nature, and all three WTC collapses showed no signs of chaotic features at their onsets.

Resources to check for serious calculations for this above, most likely scenario :

1. Charles M. Beck, mathematical/engineering calculations :
[0808.2846] Role of Compaction Ratio in the Mathematical Model of Progressive Collapse :
arxiv.org...

[0806.4792] Descent curve and the phases of collapse of WTC 7 :
arxiv.org...

DSpace@MIT: An overview of progressive collapse in structural systems :
dspace.mit.edu...

Architects Guide from the AISC, 311 pages

Stabilization of Buildings - Homeland Security 371 pages Engineering 2009

2. HUGE WTC Evidence based research website by Major Tom, where ex-JREF famous serious forum members posting their contributions on this highly technical research site, a now 5 years old JREF-offspring site :
www.sharpprintinginc.com...

Author's (Major Tom) Conclusions - World Trade Center Evidence-Based Research

The 9/11 Forum • Portal :
the911forum.freeforums.org...

3. Basement Explosions, 5 long extensive evidence pages at the Loose Change Website - Version 2.0 with lots of solid explanations of the strange early explosions witnessed in the lobby and 5 sub-basement levels of both the Twin Towers.

4. 911 Technical Papers, Image Library and WTC Collapse Simulator Site by femr2, also a former JREF forum famous serious poster :
femr2.ucoz.com...

5. WTC 1 early structural photos :
algoxy.com...

6. Case Studies: Historical Fires: Windsor Tower Fire

7. Backgrounder on Russian Fuel Air Explosives ("Vacuum Bombs") by Human Rights Watch

8. The False Assumption, Implying that All Demolitions Must Be Engineered the Same Way :
911research.wtc7.net...

a reply to: LaBTop

There is no doubt that the news media knew long before hand that WTC 7 would crash down. Most of those news journalists have either retired and are keeping the secrets with them.

originally posted by: TaleDawn
There is no doubt that the news media knew long before hand that WTC 7 would crash down.

Simply because the on the ground experts knew it was going to collapse.

At approximately 2:00 pm, firefighters noticed a bulge in the southwest corner of 7 World Trade Center between the 10th and 13th floors, a sign that the building was unstable and might collapse.[44] During the afternoon, firefighters also heard creaking sounds coming from the building.[45] Around 3:30 pm, FDNY Chief Daniel A. Nigro decided to halt rescue operations, surface removal, and searches along the surface of the debris near 7 World Trade Center and evacuate the area due to concerns for the safety of personnel.

Captain Varriale told Chief Coloe and myself that 7 World Trade Center was badly damaged on the south side and definitely in danger of collapse. Chief Coloe said we were going to evacuate the collapse zone around 7 World Trade Center, which we did.

They told us to get out of there because they were worried about 7 World Trade Center, which is right behind it, coming down. We were up on the upper floors of the Verizon building looking at it. You could just see the whole bottom corner of the building was gone. We could look right out over to where the Trade Centers were because we were that high up. Looking over the smaller buildings. I just remember it was tremendous, tremendous fires going on. Finally they pulled us out. They said all right, get out of that building because that 7, they were really worried about. They pulled us out of there and then they regrouped everybody on Vesey Street, between the water and West Street. They put everybody back in there. Finally it did come down. From there - this is much later on in the day, because every day we were so worried about that building we didn't really want to get people close. They were trying to limit the amount of people that were in there. Finally it did come down." - Richard Banaciski

Notice the use of the word "pulled" to indicate it is firefighters they are talking about!

a reply to: TaleDawn

There is no doubt that the news media knew long before hand that WTC 7 would crash down. Most of those news journalists have either retired and are keeping the secrets with them.

Wasnt like it was big super sekrit about collapse of WTC 7

The FDNY had been signalling that it was anticipated WTC 7 was in danger of collapse . At 3PM a collapse zone was
established around WTC 7 - all men and equipment were withdrawn from the area

WTC 7 collapsed at 5:20 PM

After reading many threads and looking at numerous links from both sides, I still have a couple of
questions that really bug me.

I admire and salute all that have passionately put their valuable time into the research and for their
quest to find out the truth. It seems as if even after 14 years, there is still disagreement as to what
"really" happened. There is so much relevant info, on both sides of the fence, that it is hard to make
a concrete decision about the reality of what really transpired..(at least for me).

Here is a little list of things that still bother me about the whole 911 scenario.

1. Out of an entire population that supposedly "hated us for our freedom", only 19 took the mission?
Why not 15 planes hitting major cities all over the U.S. that day? After years of planning, these 19
guys decided to hit the locations they did...for what reason? Am I really supposed to believe that
their targets were the absolute highest priority that they had in mind? I am not downplaying the
lives that were lost in any way, but I fail to see how the WTC's could have been the best target in
the entire U.S. (They certainly didn't put us in an economic catastrophe).
2. What was the primary objective of hitting the Pentagon? They barely did any damage to it. Once again,
I realize there were lives lost, but they really, really, didn't accomplish much.
3. If I wanted to do the ultimate damage, I would have used ONE plane and hit a nuclear plant somewhere
that would have had far more devastating affects over the long term. Or hit 10 of them.
4. These 19 guys didn't just come up with this plan overnight. Did their planning knowledge include information
that led them to strike the WTC's at the precise floors because they KNEW this was critical in the buildings
collapsing? How did they acquire that knowledge? Was it their plan and objective to take out WTC1, WTC2,
WTC7 and WTC6 from the crashing of 2 planes? Certainly, they didn't leave this to chance and hope.
5. Please don't answer this one without contemplating it for a moment......What was their PRIMARY objective?
There were so many other ways they could have seriously "crippled" America and Americans for an extended
amount of time and 911 was their best plan? Once again, no disrespect. But it is time to ask these things.
6. They had all this knowledge to pull this off, yet they neglected to go after the president or the White House?
Surely they could have gotten enough intel to locate the presidents whereabouts. A crashing plane would
have been a serious challenge for the Secret Service to overcome in protecting him.
7. How did their respective countries benefit from these acts?. The entire world now hates them, the U.S. military
has basically had their own "jihad" on these countries ever since, and I hate to say it, but.....The WORLD is not a
safer place since 911... What did they expect to accomplish and what DID they accomplish?
8. If Osama Bin Laden was the real mastermind behind this, with his seemingly unlimited resources financially, he
sure did go about this in a very inexpensive way. He footed the bill for 19 guys for a couple years and paid for
some airline tickets to get this done?...Were the families of the 19 hijackers compensated somehow later?
9. The 19 hijackers were determined from flight boarding manifests. If some of them were actually on Terrorist
Watchlists, how were they even allowed to get on a plane?
10. 19 guys went to their death and their greatest accomplishment in life was hijacking a plane and screaming
"Allah Akbar" as they met their maker and took innocent lives?

The list goes on and grows greater by the day. It seems as if the more I learn, the more questions I have. That is
not helping me in my desire to solve this mystery/crime. Please feel free to educate me on these subjects. I
would request that answers be respectively submitted without bias towards me in presenting these questions.

I wasn't there on that day. I didn't "lose" anyone on 911. I am only able to make logical decisions from the info at
hand. I hope I am not the only one that feels as if they are getting somewhat "conflicting" info from many sources.

I am sorry if this doesn't format out right when I hit reply...I am slowly learning how to get this on the screen right.
Please make sure all submitted links are proven to be reliable. There is nothing more irritating and time consuming
than people coming onto a thread and getting into a "link war"....except for pages and pages and pages of copy & paste.

Thanks in advance.....

Was there a point to this thread?? Of course there was. Because people STILL have to be convinced that WT7 was demolished.

DESPITE

*** Evidence of plans for the New World Trade Center 7 happening as early as April 2000. 18 months prior to its demolition.

*** Witness Evidence from Deputy Director of Emergency Services Department saying the Office of Emergency Management at WT7 was abandoned before the collapse of the Twin Towers.

***Witness Evidence from Michael Hess arriving at Emergency Services Department at WT7 to see the Mayor and other key figures were NOT there when they should have been on 9/11.

*** BBC video footage of a reporter saying WT7 has collapsed around 30 minutes before it actually DID.

*** Witness to a countdown before the collapse of WT7.

*** Video Evidence in which explosions were heard prior to the collapse of WT7.

*** Witness Evidence from Deputy Director of Emergency Services Department saying there was explosions WITHIN the WT7 building when he was in it. And Another witness who was with the guy Corroborating this story (who is in the video below).



*** Evidence of WT7 collapsing at free-fall-speed for nearly 3 seconds. Evidence in itself of controlled demolition.

*** The actual video footage of World Trade Center 7 'collapsing' is EVIDENCE ENOUGH that it was a controlled demolition.

***Some New York Firefighters being told 4 hours in advance that WT7 would DEFINETELY collapse.

***New York Firefighters who were there saying WT7 came down in a classsic controlled demolition and heard explosions.

***New York Firefighters calling for 'additional handlines to mop up isolated pockets of fire' in WT7 because never in the history of the world has a streel structured building collapsed because of fire.

***New York Firefighters witnessing 'molten lava like pockets of molten steel'



*** Larry Silversteins “We decided to pull it……. And then we watched the building collapse.”

*** Demolition Experts on Camera saying that World Trade Center 7 was a controlled demolition when being shown video footage.

a reply to: jabbathehut

Point by Point

1) Why not 15 planes and why were these targets selected

Logistics - trying to hijack 15 planes at once would involve too many people would compromise operation security,
would need to train pilots - even before 9/11 were already generating suspicion aka Moussaoui and the Phoenix
memo where FBI agent commented on number of Middle Eastern type taking pilot training

As for targets , WTC, Pentagon, and presumably Capitol building (target of Flight 93) were selected by Bin Laden for
symbolic value and for reason that all were large buildings identifiable from air

WTC was called Towers of the Jews representing money, Pentagon was the Tower of War, Capitol was Tower of Laws

2) Pentagon section that was hit was destroyed, it collapsed 1/2 hour after hit, 125 people who were there were killed
Fires were started on roof deck that took 2 days to extinguish as was burning in matting under slate covering

3) Nuclear power plants have thick concrete domes surrounding reactors which would resist impact by aircraft, also are
surrounded by obstacles , cooling towers, transmission towers, etc which make attack difficult

4) That WTC collapse was not anticipated b y Bin Laden (and everyone else) - was though that would start massive
fires and burnout large section of building, causing collapse was bonus. WTC is surrounded by 40-50 story
buildings that limit areas hit to floors above this level

5) Refer to #1

6) Bush was out of town at time, also tickets were purchased 3 weeks before attack, terrorists would not have known
his schedule White House is fairly small (compared to Pentagon and other targets) and is difficult to pick up from air
as well as having other buildings around it

Will finish remainder later Have to go...

originally posted by: firerescue
a reply to: jabbathehut

Point by Point

1) Why not 15 planes and why were these targets selected

Logistics - trying to hijack 15 planes at once would involve too many people would compromise operation security,
would need to train pilots - even before 9/11 were already generating suspicion aka Moussaoui and the Phoenix
memo where FBI agent commented on number of Middle Eastern type taking pilot training

As for targets , WTC, Pentagon, and presumably Capitol building (target of Flight 93) were selected by Bin Laden for
symbolic value and for reason that all were large buildings identifiable from air

WTC was called Towers of the Jews representing money, Pentagon was the Tower of War, Capitol was Tower of Laws

2) Pentagon section that was hit was destroyed, it collapsed 1/2 hour after hit, 125 people who were there were killed
Fires were started on roof deck that took 2 days to extinguish as was burning in matting under slate covering

3) Nuclear power plants have thick concrete domes surrounding reactors which would resist impact by aircraft, also are
surrounded by obstacles , cooling towers, transmission towers, etc which make attack difficult

4) That WTC collapse was not anticipated b y Bin Laden (and everyone else) - was though that would start massive
fires and burnout large section of building, causing collapse was bonus. WTC is surrounded by 40-50 story
buildings that limit areas hit to floors above this level

5) Refer to #1

6) Bush was out of town at time, also tickets were purchased 3 weeks before attack, terrorists would not have known
his schedule White House is fairly small (compared to Pentagon and other targets) and is difficult to pick up from air
as well as having other buildings around it

Will finish remainder later Have to go...

Thanks firerescue...Hope the formatting wasn't too hard on the eyes...It even makes me dizzy when I read it.

It sounds as if they did this whole thing because they hate Jews, War and Laws?......I might not have gone in
depth enough with number 5...I didn't mean "primary target".....I meant "primary objective"....What did they
expect to accomplish? At the end of the mission of 911, the masterminds are sitting around their campfires
in their caves and they say, "Ah look, we crashed a plane into an american building and it fell down from
lousy construction...We really showed them!!..Now we will be_________________??? Insert something please.

For 911 to have taken place, there was an ENORMOUS amount of planning that was years in the making. When
our nation goes to war, the logistics are fascinatingly HUGE. We didn't know about Seal Team 6 till after the
fact. Same goes with 911. If their mission was just a symbolic gesture, then we are doomed as a species.

As to #1, they had a 75% success rate with 4 planes. I think 20 would have been just as easy logistically, thus
15 would have presumably made their targets. I have never heard if the hijackers were in communication
with each other on the morning of 911 to coordinate things....Any info on that?...Thanks

I look forward to your follow up...It helps me to see from a non biased pov and gives the subject depth while
answering these questions of mine that keep popping up.....

Firerescue, you have blown my mind...I'm gonna have to take the rest of the day off....

Your comment...

4) That WTC collapse was not anticipated b y Bin Laden (and everyone else) - was though that would start massive
fires and burnout large section of building, causing collapse was bonus. WTC is surrounded by 40-50 story
buildings that limit areas hit to floors above this level

Got me to thinking....

The plan was to only cause some fire damage and a few deaths, and say to America, "**** U"....

Instead, because they were extremely lucky that day, they got a "bonus" of 4 buildings totally annihilated,
more deaths than they planned, and..they left America confused for a week or so. Basically, in shock.

They had no idea they would be creating a mini economy for America from their actions. Think about it...

Silverstein got a huge settlement........bonus.!
The Clean UP companies made millions...bonus!
The folks that bought the steel for pennies on the dollar made money...bonus!
The U.S. gov't (Bush Admin.) came out with DHS, TSA, Echelon, Intercept, wars , weaponry sales...bonus!
911 book sales and authors/websites went thru the roof, generating its' own little economy....bonus!
The Media made MILLIONS in adverts from 911 coverage....bonus!
911 is still on peoples minds and is still debated today...(mind control?).......bonus!

The list goes on and on and on.....Maybe it is time we stop debating explosives and look at this from a
different angle.....3000+ lives were unnecessarily extinguished that day and not even the truth will bring
them back. I think we owe it to their memory and their past contribution to our society, to stop the
bickering about ridiculous theories that pop up all over the internet, and get the the heart of the matter.

JMHO

this thread is a gold mine, just sayin

originally posted by: firerescue

1.) Logistics - trying to hijack 15 planes at once would involve too many people would compromise operation security,
would need to train pilots - even before 9/11 were already generating suspicion aka Moussaoui and the Phoenix
memo where FBI agent commented on number of Middle Eastern type taking pilot training

Well to address this first point. TRAINED PILOTS. Just how trained were the 'pilots' who hijacked the airplanes in 9/11?

Well let's get the opinion of a guy who has flown a Boeing 707, 720, 727, 737, 747, 757, 767, and 777. Has even flown TWO of the airplanes that were hijacked on 9/11. Flight 175, the second airplane to hit the World Trade Center, and Flight 98 which impacted in Pennsylvania.

The guy is also a former US Airfoce Pilot of 20 years. Over 100 combat missions. A commercial pilot for PanAm and United Airlines for 35 years.

Russ Wittenberg

His key statements which I posted in another thread.

Key Statements:
***I don’t believe it’s possible for a so-called terrorist to train on a [Cessna] 172, then jump in a cockpit of a 757-767 class cockpit, and vertical navigate the aircraft, lateral navigate the aircraft, and fly the airplane at speeds exceeding it’s design limit speed by well over 100 knots, make high-speed high-banked turns, exceeding — pulling probably 5, 6, 7 G’s. And the aircraft would literally fall out of the sky. I couldn’t do it and I’m absolutely positive they couldn’t do it."

***“For a guy to just jump into the cockpit and fly like an ace is impossible – there is not one chance in a thousand,” (recalling that when he made the jump from Boeing 727’s to the highly sophisticated computerized characteristics of the 737’s through 767’s it took him considerable time to feel comfortable flying.)

***“The government story they handed us about 9/11 is total Bullsh1t plain and simple.” (Wittenberg convincingly argued there was absolutely no possibility that Flight 77 could have “descended 7,000 feet in two minutes, all the while performing a steep 280 degree banked turn before crashing into the Pentagon’s first floor wall without touching the lawn.”)…

***“Regarding Flight 77, which allegedly hit the Pentagon. “The airplane could not have flown at those speeds which they said it did without going into what they call a high speed stall. The airplane won’t go that fast if you start pulling those high G manoeuvres at those bank angles. … To expect this alleged airplane to run these manoeuvres with a total amateur at the controls is simply ludicrous…”

a reply to: jabbathehut

Bin Laden objective by striking WTC/PENTAGON?CAPITOL was to provoke US into invading Afghanistan

Bin Laden envisions trapping US in prolonged guerrilla war similar to that waged by Afghans and Arabs against
Soviets in 1980's.

While US was to be bogged down in Afghanistan, Bin Laden would foment rebellions against US Allied governments
Saudi Arabia, Egypt, Jordan, Pakistan) and install "Islamic" governments which would then proclaim a
Caliphate

Targets were chosen for their symbolism to Bin Laden and his followers - something we in west have trouble grasping

As for increasing number of attacks - each hijack team was 5 members (4 for Flight 93) , Increasing number of attacks
means moving more people, who in turn need money which means moving more money. This increases chances
for discovery - plot almost came apart when Moussaoui was arrested wanting to fly a 747, but not land. Washington
bureaucrats refused to allow local FBI office in Minnesota to search his laptop.

This plot was distilled version of BOJINKA plot of 1990's - Ramzi Yousef (nephew of Khalid Shiekh Mohammed, ringleader for WTC plot)

Yousef intent was to plant small bombs in dozen trans Pacific airlines crashing them into ocean

Conducted a test run on Philippines Airline Flight 434 - plane was badly damaged, but able to land safely, ! passenger
was killed

en.wikipedia.org...

en.wikipedia.org...

Plan came apart when Yousef and accomplice were cooking up batch of explosives started a fire - police arrived and
were able to arrest his accomplice and seize laptop computer with details of plot.

a reply to: jabbathehut

Silverstein got a huge settlement........bonus.!

As per terms of WTC lease Silverstein was responsible to rebuild the complex. He had to pay off the mortgage he took out to finance the deal and was still responsible for the rent payments of 10 million a month - for a smoking hole in ground

Not such a good deal....

As for media - diasster coverage is not very profitable because cant run commercials - running ads for tampons between
scenes of death and destruction does not work

Airlines took a major loss as nobody wanted to travel, vacation industry was deeply depressed, economy went into a down turn from the shock to system . Stock markets (based in lower Manhattan) were closed for week

Very few if anybody made out because of WTC

originally posted by: firerescue
Bin Laden objective by striking WTC/PENTAGON?CAPITOL was to provoke US into invading Afghanistan

Which would achieve WHAT exactly?

a reply to: Debunkology

I don’t believe it’s possible for a so-called terrorist to train on a [Cessna] 172, then jump in a cockpit of a 757-767 class cockpit, and vertical navigate the aircraft, lateral navigate the aircraft,

You conveniently forget that Hani Hanjour had a multi engine commercial pilots license.
You conveniently forget that Jarrah had a single engine commercial pilots license.
You conveniently forget that Hani Hanjour had 21 hours in a 737 flight simulators.
You conveniently forget that Atta and Alshehhi had 2 lessons (90 min ea) in 727 simulators.
You conveniently forget that Atta and Alshehhi had 1 lesson in a 767 simulator.
You conveniently forget that Atta and Alshehhi were offered jobs as co-pilots for a new (now defunct) airline.

The list goes on and on and on.
Please Please Please get off these conspiracy sites and look for the real truth.

These so called military experts didn't even look into the extensive training that these hijackers took.
These hijackers were not off the street idiots ! They started their flight training 5 years before 911.

Look through this one page and then tell us how they couldn't fly planes.

a reply to: samkent

Are you serious? Sadly, I'm afraid you are.

FAA certificates are issued based upon "minimum standards". An applicant must meet minimum standards to get the license, but that does not mean he's a good pilot.

Hanjour and others had terrible reputations within the flight instructor community, at least according to what has been printed in the mainstream media 13 years ago.

All the aircraft involved were operating well beyond their limitations for airspeed and other values. There is a fair list of pilots who fly those airplanes for a living who say they could not perform the maneuvers required for the official story to be true.

Yet you believe whatever you are told.

a reply to: Salander

Hanjour and others had terrible reputations within the flight instructor community,

I agree totally.

TFAA certificates are issued based upon "minimum standards". An applicant must meet minimum standards to get the license, but that does not mean he's a good pilot.

Once again I agree.
But that doesn't mean they could not control the planes.
Remember they took over in straight and level flight.
Also they didn't concern themselves with landing the planes.
Even you could fly an airline for 1 hr and then crash.

There is a fair list of pilots who fly those airplanes for a living who say they could not perform the maneuvers required for the official story to be true.

Look at the flight path. It's no big deal.
flight path
Also just because the plane was outside the normal flight envelope doesn't mean it's going to snap in half.

Most of these 'pilot claims' are from pilots who haven't looked at the FDR's.
Do you think the big bad government would use FDR data that couldn't happen?
"Hey Joe lets make the plane pull 20 g's."

Where's the flood of pilots saying it can't be, in the days after 911?
What you are saying is that all commercial pilots before and after 911 are hiding the governments secret.
Pilots talk. Things get around.
Pilots get fired. Fired people get pissed. Pissed people talk #.
Where's all the talk? There should be thousands of pilots on youtube.