Social networks filled with laughter and derision on Sunday, in response to the bizarre claim by Donald Trump’s aide, Kellyanne Conway, that the new White House press secretary, Sean Spicer, had not lied to the nation about the size of the crowd at Friday’s inauguration, but merely presented “alternative facts.”

Conway introduced the concept when pressed by Chuck Todd of NBC News to explain why the president had asked Spicer to use his first appearance in the White House briefing room, on Saturday, to falsely claim that the National Mall was filled to capacity during Trump’s inaugural address on Friday.

With a jaw-dropping disregard for objective reality, Spicer had berated the White House press corps for reporting, accurately, that Trump’s own estimate that up to 1.5 million people were on the mall was wrong.

Since much of what Spicer said in support of his case was demonstrably false, Conway’s phrase was widely mocked.

The brazenness of this attempt by the new White House to present entirely false assertions about objective reality as equally valid alternatives to factual information reported by the media is stunning. But given how important accurate statistics and evidence from the United States government are to science, the economy and our society, it is worth laying out clearly that Spicer’s claims about the inauguration are contradicted by evidence available to anyone with the power of sight.

“We know that from the platform where the president was sworn in to Fourth Street holds about 250,000 people,” Spicer told the press corps on Saturday. “From Fourth Street to the media tent is about another 220,000, and from the media tent to the Washington Monument, another 250,000 people.”

“All of this space was full when the president took the oath of office,” Spicer claimed.

Leaving aside that this would put the size of the crowd at 720,000, not 1.5 million, photographic evidence, webcam images and video shot by reporters who observed the address from a media tent at the back of the crowd show conclusively that the area of the mall around the tent and in front of the Washington Monument was largely empty.

First, about 40 minutes before Trump was sworn in, a Washington correspondent for The New York Times, Binyamin Appelbaum, compared an image taken from the Washington Monument with a photograph from the same vantage point on the day of former President Barack Obama’s first inauguration, in 2009, which showed a much smaller crowd this year.

Second, as the Reuters photo editor Jim Bourg noted on Facebook, the area at the rear of the mall did not fill in much during the event, as seen in an image taken from the top of the Washington monument by a Reuters staff photographer, Lucas Jackson, at 12:01:18 p.m. right after Trump was sworn in.

Third, a timelapse video of the mall, created by PBS Newshour using footage recorded from 7 a.m. to 1 p.m. by a pool camera atop the Washington Monument, shows that the area was not filled to capacity at any stage during the event.

Fourth, Raj Mathai, a news anchor for the NBC affiliate in the Bay Area, recorded video during Trump’s address which showed that the area in front of the media tent, at 12th Street, was largely empty.

In another clip, streamed live to Periscope by Mathai just after Trump spoke, as Jackie Evancho sang the national anthem at 12:25 p.m., it is clear that there were hardly any spectators in the area in front of the media tent.

Fifth, readers who are loathe to accept as genuine even time-stamped video posted on Twitter by a reporter can consult a truly objective source: images of the mall and the area around the Washington Monument recorded during Trump’s address by a webcam mounted on the Smithsonian Castle’s north flag tower.

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A screenshot from a webcam showing the National Mall at 12:15 p.m. on Friday, as Donald Trump gave his inaugural address.

Photo: Earthcam

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A webcam view of the media tent in front of the Washington Monument during Donald Trump’s inaugural address on Friday.

Photo: Earthcam

Earthcam, a site that makes those images available online in cooperation with the National Park Service, later posted archived video of the live stream from Friday on Facebook, which gives skeptics the opportunity to examine the evidence for themselves.

That archived video, which is without sound, shows the mall during the entire event. Here is a portion of that video recorded during the last three minutes of Trump’s address, beginning at 12:15 p.m. on Friday.

(Visual clues confirm that the video does indeed show the scene on the mall at 12:15 p.m., matching the time the live stream began on Facebook. At that stage in his speech, after Trump said, “We will no longer accept politicians who are all talk and no action, constantly complaining, but never doing anything about it,” the pool camera used in television coverage cut away to two shots of spectators during a pause for applause. By enlarging the Earthcam video from Facebook above, it is possible to match the frames visible on the giant monitors on the mall with that part of a time-stamped copy of the live broadcast.)

What the visual evidence shows, then, is that even if we accept Spicer’s unsourced claims about the capacity of the mall, large parts of the section from 4th Street to the media tent at 12th Street, which he said holds 220,000 people, were unfilled, and the section from the media tent to the Washington Monument, “another 250,000,” was nearly empty. So even if the front section did hold 250,000 people, the total crowd would appear to have been closer to 400,000 than 1.5 million.

As part of the effort to assuage his boss’s bruised ego, Spicer also falsely told reporters that it was harder for spectators to get through security and on to the mall than in previous years, a claim which was debunked by the Secret Service. He then said that the white floor coverings, which made the absence of people more visible in photos, had never been used before (they were used in 2013, at Obama’s better-attended inauguration).

Finally, Spicer presented reporters with incorrect statistics about the volume of traffic on the D.C. subway system on Friday, saying that it was far higher than it had been on the day of Obama’s second inauguration, in 2013, when it was, in fact, far lower.

While Spicer and Conway have taken much of the flak for these whoppers over the past 24 hours, it is important to keep in mind that they are simply covering for the primary fabulist in the White House: Donald Trump.

Trump furnished a clear example of this on Saturday, just before Spicer appeared to confront the press, when he falsely claimed during a speech at the CIA that the rain had stopped and the sun had come out as he delivered his inaugural address the day before to what “looked like a million, a million and a half people.”

That surely marks the first time a president of the United States has lied about the weather at a public event he attended alongside hundreds of thousands of other people just 24 hours earlier.

White House aides who spoke to The New York Times on Sunday said that Spicer’s desperate effort to contest observable reality was prompted by Trump’s own insecurity over the relatively small crowd. “Mr. Trump grew increasingly angry on Inauguration Day,” The Times reported, “after reading a series of Twitter messages pointing out that the size of his inaugural crowd did not rival that of Mr. Obama’s in 2009.”

Aides told The Times that Trump was miffed by the tweet from their colleague Binyamin Appelbaum, which was shared more than 100,000 times on the social network that the new president seems to rely on for reassurance and approval.

What Americans, and the media, have yet to fully absorb is that the president of the United States is now a man who managed to get 62 million votes, 46 percent of the total, despite a life-long record of making one demonstrably false claim after another. Having spent the five years before he ran for office gaining support by peddling the conspiracy theory that Barack Obama was not born in Hawaii, Trump then went on the campaign trail and told voters that he had seen non-existent video of “thousands and thousands” of Arab-Americans cheering in New Jersey as the World Trade Center collapsed on September 11, 2001.

When pressed to explain that false claim by reporters, including George Stephanopoulos of ABC and Katy Tur of NBC, Trump simply doubled down.

Although that falsehood was, briefly, a central concern for the media in late 2015, Trump just refused to admit that he was wrong, even after it became apparent that there was no such footage, for the good reason that mass celebrations had not taken place.

In the end, Trump managed to wriggle off the hook for that lie, as he did for the lies about Obama’s birth certificate being fake, mainly because his opponents for the Republican nomination, many of whom are now in government alongside him, refused to challenge him on lies about Democrats or Muslims that were, and still are, popular with their voters.

Trump, like much of the Republican base, relies on entirely skewed sources of information for his news, and has yet to pay any serious price for embracing conspiracy theories and treating internet rumors as facts. His reckoning with stubborn reality is long overdue, but it might not come until those around him stop shielding him from the truth.

It is worth noting, too, that Trump is the first president to rely so heavily on a social network for information, and the rise of social media has had a profound impact on the ease with which fiction can be mistaken for fact.

That’s not to say that the willingness of partisans to believe false information is at all new. A British clergyman, C.H. Spurgeon, observed in 1859, that rumors seemed to spread more easily than facts. “It is well said in the old proverb, ‘a lie will go round the world while truth is pulling its boots on,'” Spurgeon wrote. More than a century before that, the Irish satirist Jonathan Swift noted in his 1710 essay on “the Art of Political Lying,” that “Falsehood flies, and the truth comes limping after it.”

Still, while lowering the barrier to who can broadcast accounts and analysis of news events to a global audience has added so much to our understanding of the world, it has also made it far easier for junk information, misunderstandings and even deliberately false claims to circulate widely.

A perfect illustration of how difficult it now is to correct false information is the number of Trump supporters who responded to the clear overhead visual evidence of empty spaces at the back of the mall by sharing alternative views, taken from the front of the crowd at the Capitol, without any awareness that they were captured on telephoto lenses that foreshorten and distort the distance between objects.

By Sunday afternoon, a graphic comparing a distorted telephoto image to more clear shots taken from overhead had spread as far as Brazil.

This post was updated to incorporate new visual evidence at 11:37 a.m. on Monday, January 23.

Top Photo: A screenshot from a webcam showing the National Mall at 12:15 p.m. on Friday, as Donald Trump gave his inaugural address.