i my name is richard gage a i a i've been a practicing architect for twenty years and i'm a member of the american institute of architects i became interested in the world trade center high rise collapses on nine eleven after hearing the startling conclusions of a reluctant nine eleven researcher david ray griffin on the san francisco bay area's k p f a radio guns and butter with bonnie faulkner in march of two thousand and six this is changed my life radically and launched my own personal and professional quest for nine eleven truth inspiring me to found architects and engineers for nine eleven truth we're proud to be a part of the international nine eleven truth movement which is growing by millions every year we now have hundreds of architects and engineers for nine eleven truth demanding a real investigation this is our website you can find on the right side the bullet points of information that we're going to be going through today it's eighty nine eleven truth dot org on the left side you'll see the powerpoint you can step through it at your own pace because you may not have time to follow and read all the text and absorb the information that we're rapidly going to be going through you can also watch the d v d on the left side you can sign a petition after you find yourself convinced the ever growing number of architects and engineers for nine eleven truth are not conspiracy theorists we're building and technical professionals looking at the science based forensic evidence in the destruction of these high rises on nine eleven first let the technical truth emerge then if necessary cope with the inevitable conspiracy and other questions tonight we're presenting to you the technical truths the evidence found for the explosive demolition of all three world trade center high rise collapses on nine eleven the iconic twin towers and the mysterious building seven let's begin with an overview of the events of that morning in order to start us off on the same page looking at the jets and the impacts and how this myth developed on september dazed by the news the american public soon believed the fires in the towers had burned so hot they caused the steel frames of the buildings to give way a myth developed fed by official sources through the media to what the will do to audience elements of the myth the impact of the airplanes gallons of burning jet fuel out of nowhere and just rain right into the side of the twin tower exploding through the other side and then i witnessed both towers collapse one first and then the second mostly due to structural failure because the fire was to attack the made into the it was the combination of the impact doing great damage to the building followed by fire the cost collapsed let's take a look at that buildings are destroyed by a number of different forces each of which have very characteristics for instance fires affect buildings quite differently than controlled demolition fires by their nature tend to creep from place to place as they run out of fuel moving to fresh new fuel sources leaving the burned out area to cool so when collapses do occur and by the way you'll note that they've never occurred in over one hundred examples of very hot very large and very long lasting fires buildings tend to fall over they fall asymmetrically they're burned out on one side organically if you will it's a natural process they don't fall straight down through the path of greatest resistance these particular buildings collapsed and they follow the path of least resistance or they fell over you can see that the building structure holds the building together in some recognizable form the structural elements have not been dismembered from each other and the concrete is not pulverized to dust they follow the path of least resistance which is generally over these buildings exploded witnesses hear sounds of explosions they see flashes of light there's thick bellowing and enormous pyro plastic clouds of polarized concrete the expansion of the gases very quickly produces this kali flower like formation that we see in the smoke this is a controlled demolition let's focus on this type of destruction first we have hundreds of examples from all across the country from which to make a comparison because it's the most commonly used method to demolish high rises this is what a high rise looks like when it's being demolished with explosives let's take a look at some of the key characteristics of controlled demolition first we have a sudden onset of destruction at the base of the structure we have straight down symmetrical collapse into its own footprint because demolition waves remove the column support resulting in a freefall speed virtually through the path of what was the greatest resistance thousands of tons of structural steel we have a total dismemberment of the steel structure so isn't ready for shipment we have minimal damage to adjacent structures sounds in flashes of explosions heard unseen by witnesses enormous clouds of pole variety of concrete squibb sometimes explosive charges that go off at the wrong time chemical evidence of cutter charges these are all fairly typical and they go to show us direct evidence of explosive destruction and now the interesting thing is that not one of these typical characteristics of controlled demolition can be explained or accounted for by fire let alone all ten of them typically will have government documentation expert corroboration for knowledge and video documentation all of which supports the hypothesis of controlled demolition providing proof beyond a reasonable doubt let's take a look at world trade center seven now it was forty seven stories tall what would have been the tallest building in thirty three of our states half the heights of the twin towers dorf the only by its proximity to what was for a couple of years the tallest buildings in the world it was not hit by an airplane it was the third world trade center high rise to collapse on nine eleven at about five twenty in the afternoon world trade center seven was hit by debris from the north tower you can see it being pelted here and it sustained about eight fires according to nist on various floors this is the world trade center seven forty seven stories high don't be confused by the shadow from this building here we have the twelfth and thirteenth floor fires and the seventh floor fire on the north side of the building the opposite side of the building that was being pelted by the north tower now let's take a look at the evidence of world trade center seven and see how it stacks up against the typical features of a controlled demolition starting with is there a sudden onset of destruction let's listen to this emergency room in the building at  ripping through the building and windows busting out and then the building coming down do we have a straight down symmetrical collapse into the building's footprint let's listen to dan rather narrate this collapse for not what then deliberately destroyed by well placed dynamite to knock it down down never repeated these words after this first day in fact we didn't see this building coming down after nine eleven let's take a look and this side by side comparison with the known controlled demolition on the right did the building fall into its own footprint pretty much so a little bit of overlapping into the street do we have demolition waves and how do these remove the columns support world here's a floor plan of building seven now to bring a building smoothly symmetrically into its own footprint without falling over what we have to do is remove the core columns because what we want to do is bring the outside of the building in on itself now this involves a high degree of precision that fire is not capable of do we have a freefall speed of collapse through the path of greatest resistance you can see second by second the building gaining downward momentum you can plot the drop distance on a graph of time and it fits the freeflow curve almost perfectly what does this mean that columns had to have been removed and removed virtually simultaneously on each floor synchronistically time so the building had no resistance virtually on the way down do we have a total dismemberment of the steel structure we had a forty seven story skyscraper compressed to four stories how does this happen do we have sounds of explosions  smoke from the polarized concrete watch the concrete in trained in the air racing down every street in each direction at thirty five miles an hour is incredible volume pyro plastic dust and folding itself it takes incredible quantities of heat to create this kind of action a lot more heat than the eight various fires that were on these floors do we have pools of molten iron let's start with the south tower now this section applies to the world trade center twin towers and building seven we're told by nist that this substance must be melted aluminum from the airplane but melted aluminum looks like melted aluminum it's still very it doesn't glow in daylight conditions as of twenty one days after the attack the fires were still burning and molten steel was still running says world trade center structural engineer lesley robertson to a conference of structural engineers on october fifth two thousand and one one month after nine eleven fires burned molten metal flowed in the pile of ruins still settling beneath my feet well what do the first responders in the demolition contractors say about molten metal saw pools of literally morton steel more metal being just been totally melted it was dripping from the molten steel steel flowed in molten streams they're finding molten steel and this structural engineer was understanding from berkeley sites and documents i saw melting of girders in the world trade center one of the more unusual artifacts to emerge from the rubble is this rock like object that has come to be known as the meteorite this is fused element  of steel molten steel concrete and all of these things all fused by the heat and architects engineers people who work with steel and welders have just never seen the level of destruction and the marvel of d mation of this material in our lives here is building seven at a and b and here is the north tower and the south tower these hot spots are thirteen hundred forty to thirteen hundred seventy degrees these are the temperatures of the hottest office fires there was no fire on the surface of ground zero after the collapses what are we measuring here we're measuring the molten metal that was seen by these first responders four five six stories down below in the basements that was surely at least twice or three times these temperatures what's the problem with that office fires eag says twelve hundred degrees on this claims eighteen hundred degrees for which we have no evidence for office fires of that temperature in the trade center towers structural steel doesn't even begin to melt until twenty seven hundred or so degrees we're missing a thousand to two thousand degrees of temperature heat energy required to produce this stuff where is it coming from we'll be taking a look at a possible suspect thermite which reaches temperatures of forty five hundred degrees let's listen to john gross lead engineer of nist tell us about the molten metal from metal and what is thermite anyway thermite and incendiary used by the military thermite is a compound of iron oxide in aluminum which when ignited sustains an extreme heat reaction creating molten iron in just two seconds there might can reach temperatures over forty five hundred degrees fahrenheit quite enough to liquify steel we know that open air fires cannot burn hot enough to melt steel but metal had melted at the base of the towers appendix c of the female report describes sulfur residues on the world trade center steel the new york times called this the deepest mystery of all cell first slightly lower is the melting point of iron and iron oxide and iron sulfide had formed on the surface of the structural steel sulphur used is called thermal producing even faster results dr stephen jones performed chemical analysis on the previously molten metal he sent a sample from this forty pound chunk of previously molten metal from one of those meteorites he finds out it's predominantly iron so we can rule out aluminum from the jet point it has small amounts of aluminum sulphur and potassium appear to be the thermite fingerprint gel explosives are a super thermite a tiny aluminum particles and iron oxide in this all gel they can be cast into shape they're like a clay lawrence livermore lab did research on this and this invention offers a thermite based apparatus for cutting target materials you pack the thermite in here and you ignited and it comes out and is forced through melting this structural steel element in fractions of a second almost as effective as high energy explosives r d x and c four which are more common in classic controlled demolitions if sol gels were used they would leave behind a very unique signature one three die final propane and in fact e p a finds one molecule in their talks a logical studies at levels that dwarfed all others one three fennel propane eric schwartz says we've never observed it in any other sampling we've ever done but is there evidence of  world trade center dust dr jones received no less than four separate samples of world trade center dust some of it from jeanette mckinley's apartment across the street where the windows blew in and filled her apartment with dust another sample was found like ten minutes later on the brooklyn bridge well he takes this and he puts a magnet over it and he finds that there are small particles that come up to the magnet some of them are angular some of them are round they look like this in fact he calculates by the weight of the amount of these spheres that he finds in the dust that there must have been about ten tons for the whole for all of the dust that was available there are about a sixteenth of an inch in diameter the largest ones and most of them though are smaller and the human hair what could produce such an incredible array of microspheres well if you had thousands of cutter charges going off in the columns and beams throughout the building and they were under this incredible pressure what you'd see is something like this tens of thousands or millions of tiny droplets what's the shape of those droplets when a liquid is dispersed like this its surface tension forms itself into almost a perfect sphere in the case of molten iron that those droplets cool and they fall along with the dust everywhere we have iron manganese and in the case of this known thermite signature it matches basically in other words we have a controlled experiment to compare the results against dr jones is not the only one who finds these iron rich microspheres the e p a finds them and all the dust in the tox a logical studies they're doing they have no idea where they came from and they sweep it under the rug it has only one possible formation and that is from liquid molten iron under extreme pressure r j leaf finds the iron rich microspheres on top of the deutsche bank building in their talks logical studies with dr jones concludes a given the mix of trace metals present in these high concentrations in the dust such as zinc copper manganese and the formation of iron rich aluminum clear that significant illuminate their mic reactions occur and he can reverse engineer this and suggest to us that there must have been in the thermite mix powders of aluminum iron oxide copper oxide zinc nitrate and potassium well when there possibly be any a nickname did thermite pieces in the world trade center dust indeed find it it also comes up to the magnet from his dust samples many ships this one a sixteenth of an inch long red on one side gray on the other the red side is composed of tiny iron oxide particles and aluminum in fact he does an x e d s on this stuff too and he made in a cave in afghanistan the lawrence livermore lab came out with papers only a year or two ago about this stuff the particles being so small allow for almost instantaneous  between the two chemicals aluminum in the iron oxide producing very explosive results los alamos lab m le lawrence livermore lab have produced these results then he continues his study and fin additional chips that are partially ignited with spheres embedded in them indicating that the source of this fears is for all intents and purposes identified very clearly with dr jones results coupled with the visual evidence he says at the scene such as the flowing hot liquid metal providing compelling evidence that thermite reaction compounds were deliberately placed in both world trade center towers and building seven but these results are documented in a peer reviewed journal and all of this is direct evidence of explosive destruction in building seven come jump back to only building seven now now none of these characteristics can be explained by fire let alone all of them let's listen to what feynman did conclude because it is interesting evidence of a severe high temperature corrosion attack on the steel including rapid oxidation sulphide a sion and subsequent entered granular melting very interesting remember office fires don't melt steel what melted the steel sulfur form during this hot corrosion attack on the steel here is the interger a new learn melting documented for all of us thank you bill of turning a solid steel girder into swiss cheese like this former white flange column from the structural steel in building seven now they document this very carefully in their appendix c the specifics of the fires in world trade center seven and how they caused the building to collapse remain unknown at this time what unknown the best hypothesis fire plus random damage and then complete collapse has only a low probability of occurrence further research investigation and analysis are are needed to resolve this issue but unfortunately for those hoping to resolve the issue much of that evidence had already been destroyed about ninety nine percent of it in fact by fema in fact eight hundred truckloads a day easily the third the three worst structural failures in modern history two hundred fifty pieces were saved crucial evidence that could answer the questions on the slow boat to china exclaims bill manning editor in chief of the hundred twenty five year old fire engineering magazine that brings together fire protection engineers to communicate with each other and showing an astounding ignorance of the government officials to the value of a thorough scientific investigation the destruction and removal of evidence must stop and immediately commission a fully resourced blue ribbon panel to conduct a clean and thorough investigation how about expert corroboration how about any joint go twenty seven year controlled demolitions expert it starts from below they've simply blown away the columns it's controlled demolition a team of experts did this it's professional work without a doubt building seven do we have any for knowledge of its destruction listen to these construction workers walking away from building seven and this police officer and what did he say the last few seconds he took for you heard three two one countdown does that imply for knowledge do fires bring buildings down to countdowns unlikely in fact the b b c announces the collapse twenty minutes before it happened and it's true jane stanley is here announcing it she says the forty seven story solomon brothers building close to the world trade center has also collapsed and there it is standing behind her the b b c apologizes for this grievous error citing a confusing events of the day but does that make them psychic unlikely is there some kind of script that's  handed out like the guy on the street of the twin towers who had all the answers but i believe we've shown that building seven matches all of the features of controlled demolition in the classic sen is it likely that al qaeda could have had access to this building which had to have been one of the most secure outside the pentagon if they didn't then who did the evidence is even more clear in the case of the twin towers it's generally more difficult for people to understand that the towers were a controlled demolition because it was so outside of our frame of reference we'd never seen anything like this so this combined with the shock kept us from being objective but if you were to plan a fire induced collapse as a result of airplanes you'd start the explosions at the point of jet plane impacts so in world trade center two and one we have all of the key characteristic features of controlled demolitions but with some of these key differences we have beginning of detonation at the point of jet plane impacts not at the base of the building in addition we have not an implosion but where everything is being exploited outside the footprint we have squibs or these mistimed explosions and as we already discussed the evidence for thermite in the molten metal and in the dust in the iron rich microspheres so let's take a look starting with the sudden onset and what is the evidence for this and how is it produced produced by these sounds and flashes from the explosion one hundred eighteen of these firefighters witnessed sounds and flashes of explosions we felt the ground shake you could see the towers sway and then it just came down all of a sudden the ground just started shaking it shook my bones shortly before the first tower came down i remember feeling the ground shaking somewhere around the middle of the world trade center there was this orange and red flash coming out initially just one flash then it just kept popping all the way around the building the building it started to explode like on television they blow up these buildings seem like it was going all the way around like a belt all these  explosions pop up up that's when i heard the building coming down saw a brief number of light sources being emitted from inside the building between floors ten and fifteen i saw low level flashes we actually heard the pops you know you heard the pops of the building it was blowing out on all four sides why did these guys experience that how about the news reporters what do they say they tend to tell the truth on the first day and then we don't hear the truth again what happens to it anybody who's ever watched a building being demolished on like an explosion it was a huge explosion albert curry said that there was another explosion which took place and then an hour after that there was a nother explosion in one of the towers here so according to his theory he thinks compare these explosions to a known explosion on the on the left here upward outward arching streamers pyro plastic volumes of dust symmetrical display like a mushroom does it look like a gravitational collapse to you let's look at the north tower now what i want to point out to you is that you're going to see some explosions up at the top of the building curiously enough and what's going to happen is this entire section is going to telescope such that half of it its upper half is destroyed before there's any movement from the jet plane impacts down let's take a look at the first evidence of the blows and  was let's take a look now closer up right away we're seeing clouds forming up here well wait the collapse is supposed to be just down here but we have  asymmetrical damage to this building the right the plane went in one side and yet this complete symmetrical collapse will using quotes from now on and let's keep going on expecting one more time  terms of house belts just like the fireman saw all the way around the building the antenna falls first before anything else falls indicating couper column damage first now take a look at this from the same tower from the bottom noting the violence underneath the mushroom cloud the collapse of supposed to be occurring way up here but down below as you'll see in the second run incredible quantities of squibs explosions bursting out and on the third time i'd like to direct your attention to this racing series of explosions down the right side and a corner of this building about forty stories below the collapsing building it's gets painfully obvious after a while doesn't it do we have a straight down symmetrical progression of collapse outside the footprint we had a two hundred seven foot wide building famous tells us and we can see in this document that we have a twelve hundred foot debris field equally distant around each tower asymmetrical damage symmetrical distribution all through the site in fact and beyond do we have squibs or these mis timed explosions some believe that these might be propre at lead time to explosions whatever in all the videos of the collapses explosions can be seen bursting from the building twenty to thirty stories below the demolition wave here and here now in this tells us that these are puffs of air being produced by the collapsing building pushing air down the highest way like a piston it's got to come out somewhere right well first of all these are not puff they're polarized building materials and they occur at one hundred sixty to two hundred feet some of them per second these velocities are propelled by explosives twenty forty and sixty stories below how can the piston be producing all of that and in fact there there are these focalized rejections that occur half way between the corners of the building also if say this was the open office space space right sixty feet long weighs over here the piston is going to shove the air into this room it's going to fill and the room fairly uniformly with air pressure before it breaks any windows right and then it might break several but galileo's love falling bodys calculates the time in which an object will travel a certain distance in complete freefall distance d equals sixteen point eight times tion second squared the south tower was one thousand three hundred sixty two feet tall thirteen sixty two equals sixteen point zero eight times a four point seven or nine point two seconds the twin towers came down a nearly free fall speed what are we talking about here let's just try to put this in perspective with this story problem we have a fifteen story building which we hold with this crane over ninety five stories of nothing but air no resistance right just airways is next to it another fifteen story building held over a ninety five story building with say eighty thousand tons of structural steel in now we're going to pull the lever on these cranes and drop them both at once i brought a ninety five story building with me today and we're going to just test this theory of nist i've got two fifteen story buildings we've got eighty thousand tons of structural steel in this one right here and we've got air resistance here so let's try it ok we'll put them both up here we'll even give a little bit of impact load to ok ready three two one oh my god the one without any resistance under it hit the ground first at virtually free fall doesn't take much does it what happened over here the the building above was it met resistance through the process the energy of defamation it came to a halt where is the fifteen story building that was driving this building down to the ground at freefall speed in the first two seconds you saw it reduced half of its mass it was blown outside it couldn't have been used to influence the downward progression of the building in the next two seconds after four seconds totally it's destroyed itself there's nothing crushing the building it's tearing itself apart at freefall speed and it's dismembering the steel structure in fact the leading edge of these mushroom clouds are full of perimeter columns aluminum cladding and other steel let's take a look at the south tower in terms of dismemberment see what's going on here south towers on your left it was hit lower by the aircraft and as you can see it's rapid destruction starts there and it begins to tilt to the left and it disappears into this cloud we would expect to see this building which is already tilted at twenty two degrees and continuing its angular momentum off center of the building below it how can it crush at freefall speed when it's already off center and we don't see it either mangled up in some heap at the bottom down on the pavement it's been completely dismembered let's take a look from fall speed doesn't make sense to me steel frame structure was completely dismembered there are no large chunks of building only those shards that we saw of the perimeter structure does it look like a gravitational collapse to you we are seeing explosions rather than implosion a first in demolition history in fact the parsons of the tower that had the greatest structural members of the sky lobbies and the mechanical floors had the perimeter units thrown up farther then the perimeter wall units from the upper floors which theoretically should have full because they're higher they should have gone farther right know these parameter units landed on their winter garden six hundred feet away what about  those pancakes were this is a pancake collapse we're looking for some pancakes down below this is a seven story lobby there is about two or three stories of stuff in there we'll take a look at that stuff but what i'm looking for is one hundred ten floors with this kind of metal decking underneath four and five inches thick of concrete and anchor in size each of them one hundred ten acres of these how many floors do we find out at the bottom not fifty not not even one we don't even find metal decking down there or concrete there's hardly any macroscopic chunks of concrete what happened to the metal decking what happened to the concrete pancakes occur in pancake collapses and how about this firefighter you have two hundred ten story office buildings you don't find a desk you don't find a chair you don't find a telephone a computer the biggest piece of the telephone i found was half of the keypad and it was about this big the building collapsed to dust and this dust made it almost across to new jersey across the river thick billowing and laying a carpet of four to six inches thick around lower manhattan polarized to two hundred micron to ten mil particles almost like talcum powder some of it it's  very very fine where's the grinder that produced this all of this is direct evidence of explosive destruction and none of it can be accounted for by fire how about that nist report we got twenty million dollars and three years what happened with our tax dollars that the task was to determine how and why world trade center one in two collapsed and how and why world trade center seven collapsed let's look at their objective the focus of the investigation was on the sequence of events from the instant of aircraft impact to the initiation of collapse for each tower for brevity in this report this sequence is referred to as the probable collapse sequence it doesn't actually include the structural behavior of the tower after the conditions for a collapse initiation were reached and collapse became they say inevitable wait a minute can spend three years and twenty million dollars and you're going to model every turban in the airplane and you're going to stop the entire investigation before the real action begins right when the point where you're going to stop at at the point where th the trust was sagging and pulling in the first column and you're just going to stop your canalis is how many engineers did you have working on this and what are you concluding this is they have ten thousand pages in this report this is the half page that explains everything after that no one alice s let's see their conclusion the structure below the level of collapse initiation offered minimal resistance to the falling building mass at and above the impact zone structural engineers do this every day why didn't they do it could it be because they knew darn well that it would not have collapsed at all wait what was the report title final report on the collapse of the world trade center twin towers probably should have called it final report on the initiation of collapse they also cast doubt on their own theory they say to us in a letter to our request for correction which several of us applied for and have yet to see adequate results from we are unable to provide a full explanation of the total collapse of the twin towers thank you we think so too do we have expert corroboration well here's van romero it's too methodical to be a chance result of airplanes colliding with the structure this explosive expert says after the airplanes hit the world trade center tower there were some explosives in my opinion inside the buildings that caused the towers to collapse mike taylor a demolition expert looked like classic controlled demolition collapse of the twin towers mirrored the strategy used by demolition experts about the structural engineer r brookman explosive clouds of dust and debris moving horizontally and vertically upward as the collapse of world trade center one and two are just beginning does not look anything like a heat induced gravitational collapse mechanism william r structural engineer also with architects and engineers for nine eleven truth the prevailing theory would have us believe that each of the twin towers inexplicably collapse the pond itself crushing all two hundred eighty seven massive columns on each floor while maintaining a freefall speed as if the hundred thousand or more tons of supporting structural steel framework underneath didn't even exist how about david scott structural engineer with eighty nine eleven truth near freefall collapse violates laws of physics this suggests all the features of a classic controlled demolition with those exceptions which are atypical of classic controlled demolition none of these features can be accounted for by fire let alone all ten of them it's proof beyond a reasonable doubt we've got to get informed and inform every other architect in engineering that you can find and everybody else that you know support a new investigation why did we not see the truth about nine eleven well it appears as if our government lied to us about the building collapses the nine eleven commission report reinforced that lie thema and nist justified it and the corporate media repeated it and they hammered it in we really didn't have much of a chance now we've shown here today that explosives were used to destroy each of the three world trade center high rise buildings on nine eleven and it's known that it takes months of planning to set up an engineer and place these explosives do we think that al qaeda had access to these highly secure buildings and the evidence you've seen tonight is just a small fraction of the vast body of information that the nine eleven truth movement has assembled the questions are numerous and ominous that must be answered in a new investigation i encourage you to discover the evidence that i have not had time to bring to you tonight it will take thousands perhaps millions of us each one of us therefore in this grassroots movement has an ultimate responsibility to take the information that we provided and disseminated get the d v d loan it to everybody you know you must become a truth bearer email the eighty nine eleven truth dot org link along with a statement saying check this out to every architect and engineer you can find and everybody you know we will turn heads in the halls of congress sign the eighty nine eleven truth dot org petition sign it demanding a new investigation stand up and be counted and everyone can sign architects engineers and all else we have several categories of people what you need to do is get one of these cards and we provide it the out of hundreds of architects we stick our neck out on the line for you let them call us conspiracy theorists all you have to do is say hey there's architects and engineers demanding a new investigation what do you think we need to act the power of truth is greater than the power of the lie so get informed and begin to let the truth speak through you and get informed through our website you have all the information you need sign the petition here follow the red arrows become a sustaining member here it's real easy given the numerous warnings of far worse terrorist attacks and war plans that are in place we need to do something big out because the time comes when your silence is betrayal thank you so very much for your attention to