Monday, 14 October 2019

Google Doodle is celebrating 218th birthday of physicist Joseph Antoine Ferdinand Plateau

Joseph Antoine Ferdinand Plateau was instrumental to the birth of cinema. 

 

The Phénakistiscope

Joseph Antoine Ferdinand Plateau invented it  which created an illusion of a moving image which was pivotal to the birth and growth of motion picture.(Google/Google Doodles)
 

Google Doodle celebrates the 218th birthday of Belgian physicist Joseph Antoine Ferdinand Plateau whose research on visual perception led him to invent a device named phénakistiscope which led to the birth of cinema. phénakistiscope created an illusion of a moving image which was pivotal to the birth and growth of motion picture.

 
 


Plateau’s father was an accomplished artist who specialized in painting flowers. Initially, Plateau studied law but later studied physiological optics, emphasizing particularly on the effect of light and color on the human retina which made him one of the best-known scientists of the 19th century. 

Joseph Antoine Ferdinand Plateau ( 1801-1883)

Born in 1801, his dissertation focussed on how images form on the retina, noting their exact duration, color, and intensity. He created a stroboscopic device in 1832 based on these conclusions in which two discs rotated in opposite directions. The first disc had been filled with small windows, evenly spaced in a circle and the other disc has pictures of a dancer in a series. The images seemed to merge creating an illusion of a dancer in motion when the discs turned exactly at the right speed.

Plateau’s productive career continued as a professor of experimental physics at Ghent University with the help of colleagues that included his son Felix Plateau and his son-in-law Gustaaf Van der Mensbrugghe despite him losing his vision in the later years of his life. 

 Today’s Google Doodle was inspired from Plateau’s discs which reflect his style with different imagery and themes in them on different device platforms.

 

 

 

 

 

 

 

 

 

 

 

Saturday, 12 October 2019

Protestors strip off and paint bare breasts in latest stunt for the Extinction Rebellion.



Extinction Rebellion protests have been taking place around the world



Wednesday, 26 October 2016

ISIS Sent Four Car Bombs. The Last One Hit Me.

ISIS Sent Four Car Bombs.

a suicide car bomb

Mr. Denton, a photographer for The New York Times, was with Iraqi counterterrorism forces as they began pushing toward Mosul last week. 

BARTELLA, Iraq — Our convoy had already been targeted by suicide car bombs three times, over a long day spent under fire. So the Iraqi forces had brought up a tank, and its main gun kept scanning the road ahead toward Mosul.

But the shouts started coming from behind us instead, and when I turned to look, I knew right away: Here was bomb No. 4, seemingly out of nowhere. By the time I saw it, the vehicle was maybe 70 feet away.


We were with a unit of elite Iraqi counterterrorism forces, who on Thursday morning were making their first moves in the broader battle to take Mosul back from the Islamic State.

The commandos’ first big objective was to surround and clear Bartella, a militant-held town about six miles east of the outer fringes of Mosul. Starting out from an Iraqi base around 5 a.m., the troops began pushing east along the main highway that links the Kurdish regional capital, Erbil, with Mosul.
Iraqi artillery targeted an Islamic State-held village.

Under peaceful circumstances, that drive would take maybe an hour and a half. But it would take the unit we were with nearly all day just to push three miles into Islamic State territory to the western edge of Bartella, where the troops were to cut off the Islamic State fighters holed up in the town, keeping them from escaping to Mosul or being reinforced from there. There were bombs all along the road, and nearly every village along the way would be a source of attack.

An Iraqi reporter for The Times and I were traveling with a television crew from the British news service ITN. We climbed up into a huge Iraqi Army MRAP — a mine-resistant, ambush-protected vehicle — in the middle of a large convoy of vehicles preparing to leave for Bartella.
Ordnance disposal specialists led the way. 

As we set out, though, the crew was told that our vehicle would be leading the way, transporting the ordnance disposal experts who would be working to clear the convoy’s routes through the fields and villages south of the highway.

I was nervous, but there was no time to stop and figure out how to shift to vehicles behind us. We hadn’t gone far, but we were already taking fire from different directions.


After cutting south, the convoy, now accompanied by an Iraqi Army M1A1 Abrams tank, headed off the road for the relative safety of the open fields, with the expectation that there would be fewer mines and improvised explosive devices, or I.E.D.s.

As we moved at about five miles per hour, passing by the small, sun-baked hamlets that dot the approaches to Bartella, we increasingly came under machine-gun fire from concealed Islamic State positions. Bullets kicked up dust around our convoy and pinged off the vehicle’s armored exterior and glass, leaving spider-web-like cracks in the thick windows.

An Iraqi officer in the lead vehicle.

Volleys of mortar shells crashed around us, the militants looking to find their range among the crawling line of vehicles, but never succeeding.

The vehicle commander, Lt. Muhammad Altimimi, repeatedly pointed out suspicious buildings and the fleeting shadows of Islamic State fighters moving among points of concealment, encouraging the Abrams tank and an armored bulldozer to push ahead of us.

An Iraqi Army helicopter fired at militants.

The first moment of tension occurred as we came upon the first stretch of paved road that the convoy had to cross.

The bulldozer went ahead, scraping away some of the pavement and building up a small berm to protect the convoy from any suicide bombers who might try to hit the dozens of Humvees as they traversed the road.

A hamlet a little more than 200 yards up the road seemed to be an ideal staging point for such a vehicle, I remember thinking. Our vehicle crossed the road without incident, but we were soon stuck in a field, calling for the bulldozer again to fill in a trench blocking our way, dug by the Islamic State for just that reason.

Watching for suicide car bombs.
 The arrival of the first suicide car bomb was heralded by the sound of machine guns and vehicle-mounted grenade launchers going fully automatic. Still waiting for the bulldozer to complete its work, we had pulled over into a barren field, more than 300 yards from any buildings.

An Iraqi Army M1A1 Abrams tank advanced
The suicide vehicle gained speed on a gentle decline from the hamlet that had seemed dangerously close, and tried to veer off-road toward a cluster of vehicles just behind us. Weighed down by steel plates painted a dull green and coyote brown, and by its explosive payload, the car careened clumsily into the field, hitting a small ditch and flipping over.

I photographed as the Iraqis fired at the overturned vehicle, sitting like a flipped turtle in the field, until it erupted in a huge explosion, raising the dust around us.

Firing at a suicide car bomb.

After the trench was filled, we were underway again, making a right turn and now heading north toward the commandos’ objective: the western edge of Bartella, and the four-lane highway that links Erbil to Mosul.

Almost as soon as we did so, the convoy began taking even heavier fire. Bullets again pinged off the vehicle, and mortar shells sent up plumes of dust around us. The front right tire of our MRAP was shot out, but the crew continued to drive forward, the vehicle’s limp becoming more pronounced as we bounced over the uneven terrain.

Lieutenant Altimimi told everyone in the vehicle, journalists included, to watch through the windows for suicide car bombs. Yelling over the radio indicated that the back of the convoy had destroyed another suicide vehicle, and a steep plume of smoke and dust was hanging in the sky less than a mile away.

A suicide car bomb detonated

We soon spotted a pickup truck parked in the shadows of an alleyway between a nearby set of buildings, and halted, just short of another stretch of paved road. Suddenly, a different vehicle, stacked with painted, makeshift armor, lumbered out from behind the buildings, making a left as it tried to pick up speed toward us.

The MRAP’s driver panicked as he tried to maneuver our damaged vehicle farther back, gunning the engine and finally finding gear as the suicide car bomb tried to leave the road.

From the limited visibility in the back of our rapidly bouncing and turning vehicle, I was just able to glimpse the car bomb as it seemed to get stuck in a small ditch, maybe 50 or 60 yards from us. The Iraqi tank had moved up beside us and took the opening for an easier shot with its main gun. The suicide vehicle blew apart, the concussion wave rocking our vehicle.

Everyone inside erupted in applause. That one had gotten close.

We limped on, eventually reaching the main Erbil-Mosul road leading west from Bartella.

Filling in a trench dug by the Islamic State.

With the front right tire almost completely disintegrated, we could barely move at more than a crawl. The ordnance removal technicians worked ahead of us, in coordination with the bulldozer, the tank and a few Humvees. Over just a few hundred yards of road, they cleared four big I.E.D.s, while Islamic State fighters kept shooting at the convoy.

The Iraqis answered with MK-19 grenade launchers and other vehicle-mounted weapons.

Ordnance experts cleared the road.
There was little for us to do other than wait in the relative safety of the vehicle while the Iraqi forces worked to clear the area and set up a security perimeter as the sun went down in the late afternoon.

Outside the vehicles, before the explosion.

We thought that moment had come when an officer knocked on the rear doors and, having removed his body armor, invited us to step out of the MRAP.

“What are you doing here?” he joked. The gunfire had stopped, and the bulldozer had built an earthen berm blocking the main highway. The Iraqi tank set up behind it with its main gun turret pointed toward Mosul, keeping watch for another vehicle bomb.

It seemed like a relatively reasonable time to photograph the column and surroundings from outside the vehicle, as soldiers milled about and began to check the buildings they would probably be occupying that night.

Iraqi soldiers walked past Islamic State graffiti.
I climbed down and began to take photographs, making sure that I kept moving and was near cover, in case there were any snipers left in the area.

I was walking back to our vehicle when someone screamed in Arabic, “Car bomb!” As I turned, I saw it, like an armadillo covered in steel plates, lumbering toward us from a narrow alleyway on the edge of town. It was about 70 or 80 feet away, and began making an almost lazy left turn, as if it were merging into traffic.


As everyone began to run, and the soldiers opened up on the vehicle, my only thought was to get low and find cover. I tried to get behind the nearest Humvee, as quick as I could run in a crouch.
I was in the open for maybe four or five seconds, but that was too long.
The explosion was huge, and I felt something hit the top of my right wrist. Somehow there was no pain yet — in the moment I actually thought of a teacher’s ruler smacking my wrist. Hard to explain.
I stopped behind the Humvee I’d been aiming for, with two Iraqi soldiers ahead of me. One of them was screaming, checking his body for wounds and in a clear state of panic.
Continue reading the main story
An Iraqi soldier wounded in the blast.

I looked down at my wrist and could briefly see the bone through a deep gash before the wound filled with blood.

I put my hand over it to apply pressure. One part of me was fixated on moving my fingers and checking the motion in my wrist, while the rest was worried about the possibility of a follow-up attack.

Another Iraqi soldier came up to me through the dust and smoke. He pulled off one of the tourniquets I keep on my body armor and started trying to apply it to my arm. I waved him off — there was no sign of an arterial bleed.

I made my way back to the MRAP, where one of the journalists from ITN helped me apply a compression bandage. I was loaded into the flatbed of a Humvee with Iraqi soldiers who had also been wounded, and we were driven back behind their lines.


I’d been incredibly lucky, and the wound looked worse than it was. There was no shrapnel lodged inside, no ligaments or tendons torn, and an X-ray at the hospital in Erbil later that night showed no signs of broken bones.

It was hard not to think about what could have happened, though. Even a slightly worse alternative would have changed everything: If the shrapnel had hit just an inch to the left, I could have lost my right hand, or the use of it.


Sunday, 23 October 2016

Hillary Clinton Presses Her Advantage Over a Struggling Donald Trump

Hillary Clinton Presses Her Advantage Over a Struggling Donald Trump

Hillary Clinton at Union Baptist Church in Durham, N.C., on Sunday.

 

Hillary Clinton moved to press her advantage in the presidential race on Sunday, urging black voters in North Carolina to vote early as Republicans increasingly conceded that Donald J. Trump is unlikely to recover in the polls.

With a strong lead in national polls, Mrs. Clinton has been pleading with core Democratic constituencies to get out and vote in states where balloting has already begun. By running up a lead well in advance of the Nov. 8 election in states like North Carolina and Florida, she could make it extraordinarily difficult for Mr. Trump to mount a late comeback.

On Sunday, Mrs. Clinton appeared at a church in Raleigh, N.C., with mothers who have lost children to gun violence or clashes with the police. Addressing the congregation, she sounded like a candidate looking past the election to a presidency in which she would have to address a deeply divided nation.
“There are many people in our country willing to reach across the divide, regardless of what you’ve heard in this campaign,” Mrs. Clinton said. “There are people — millions and millions of people — who are asking themselves these hard questions, who want to find a way to work together to solve these problems that we face.”

Geneva Reed-Veal, whose daughter, Sandra Bland, died in a Texas jail after a traffic stop last summer, called on the congregation to make its voice heard at the polls. “If you decide not to vote, shut your mouth,” Ms. Reed-Veal said.

Both Mrs. Clinton and key Republican groups have effectively pushed aside Mr. Trump since the final presidential debate on Wednesday, treating him as a defeated candidate and turning their attention to voter turnout and battling for control of Congress.

An ABC News tracking poll published on Sunday showed Mr. Trump trailing Mrs. Clinton by 12 percentage points nationally and drawing just 38 percent of the vote.

Mrs. Clinton, who drew support from 50 percent of voters in the poll, was openly dismissive of Mr. Trump over the weekend, telling reporters on Saturday that she no longer worried about answering his attacks. “I debated him for four and a half hours,” she said. “I don’t even think about responding to him anymore.”

Karl Rove, the chief strategist of George W. Bush’s successful presidential campaigns, said Sunday on Fox News that he did not expect that Mr. Trump could pull off a comeback in the final two weeks of campaigning.

“I don’t see it happening,” Mr. Rove said.

Two outside groups aligned with Republicans, the U.S. Chamber of Commerce and the Senate Leadership Fund, have begun running television commercials in Senate races implying that Mr. Trump’s defeat is likely and asking voters to send Republican lawmakers to Washington as a check on Mrs. Clinton.

And the Congressional Leadership Fund, a powerful “super PAC” that supports Republicans in the House of Representatives, will begin running ads in the coming days that attack Democratic candidates as “rubber stamps” for Mrs. Clinton, and urge voters in swing districts to support a Republican instead.

Churchgoers listening to Mrs. Clinton’s speech on Sunday.

Mike Shields, the president of the Congressional Leadership Fund, said the group had tested the message and found it effective even in areas that are likely to support Mrs. Clinton over Mr. Trump.

“There are many districts where we are going to be running ads that talk about the Democrat being a rubber stamp for Hillary Clinton,” Mr. Shields said. “In many districts, it is a very, very potent weapon to use against a Democratic candidate for Congress.”

Mr. Trump’s campaign manager, Kellyanne Conway, acknowledged on “Meet the Press” on NBC that Mr. Trump was behind in the race. She said the campaign had “a shot” at winning over undecided voters who do not currently support Mr. Trump but who dislike Mrs. Clinton.

But Mr. Trump has made little effort in recent days to deliver a sharply honed campaign message or to address the flaws at the core of his candidacy. He scheduled no public campaign events on Sunday before an evening rally in Naples, Fla., though early voting begins this week across most of the state.

In a Saturday speech that was intended to outline his closing message in the race, Mr. Trump instead began by issuing a broad threat to sue all the women who have come forward to say that he sexually assaulted them.

Ms. Conway said on Sunday that the threat was “a small piece of a 42-minute speech.”


Saturday, 22 October 2016

Hackers Used New Weapons to Disrupt Major Websites Across U.S.

Hackers Used New Weapons to Disrupt Major Websites Across U.S.

A map of the areas experiencing problems, as of Friday afternoon, according to downdetector.com.

 

SAN FRANCISCO — Major websites were inaccessible to people across wide swaths of the United States on Friday after a company that manages crucial parts of the internet’s infrastructure said it was under attack.

Users reported sporadic problems reaching several websites, including Twitter, Netflix, Spotify, Airbnb, Reddit, Etsy, SoundCloud and The New York Times.

The company, Dyn, whose servers monitor and reroute internet traffic, said it began experiencing what security experts called a distributed denial-of-service attack just after 7 a.m. Reports that many sites were inaccessible started on the East Coast, but spread westward in three waves as the day wore on and into the evening.

And in a troubling development, the attack appears to have relied on hundreds of thousands of internet-connected devices like cameras, baby monitors and home routers that have been infected — without their owners’ knowledge — with software that allows hackers to command them to flood a target with overwhelming traffic.
 
A spokeswoman said the Federal Bureau of Investigation and the Department of Homeland Security were looking into the incident and all potential causes, including criminal activity and a nation-state attack.

Kyle York, Dyn’s chief strategist, said his company and others that host the core parts of the internet’s infrastructure were targets for a growing number of more powerful attacks.

“The number and types of attacks, the duration of attacks and the complexity of these attacks are all on the rise,” Mr. York said.

Security researchers have long warned that the increasing number of devices being hooked up to the internet, the so-called Internet of Things, would present an enormous security issue. And the assault on Friday, security researchers say, is only a glimpse of how those devices can be used for online attacks.

Dyn, based in Manchester, N.H., said it had fended off the assault by 9:30 a.m. But by 11:52 a.m., Dyn said it was again under attack. After fending off the second wave of attacks, Dyn said at 5 p.m. that it was again facing a flood of traffic.


A distributed denial-of-service attack, or DDoS, occurs when hackers flood the servers that run a target’s site with internet traffic until it stumbles or collapses under the load. Such attacks are common, but there is evidence that they are becoming more powerful, more sophisticated and increasingly aimed at core internet infrastructure providers.
Going after companies like Dyn can cause far more damage than aiming at a single website.
Dyn is one of many outfits that host the Domain Name System, or DNS, which functions as a switchboard for the internet. The DNS translates user-friendly web addresses like fbi.gov into numerical addresses that allow computers to speak to one another. Without the DNS servers operated by internet service providers, the internet could not operate.
In this case, the attack was aimed at the Dyn infrastructure that supports internet connections. While the attack did not affect the websites themselves, it blocked or slowed users trying to gain access to those sites.


Later in the day, Dave Allen, the general counsel at Dyn, said tens of millions of internet addresses, or so-called I.P. addresses, were being used to send a fire hose of internet traffic at the company’s servers. He confirmed that a large portion of that traffic was coming from internet-connected devices that had been co-opted by type of malware, called Mirai.

Dale Drew, chief security officer at Level 3, an internet service provider, found evidence that roughly 10 percent of all devices co-opted by Mirai were being used to attack Dyn’s servers. Just one week ago, Level 3 found that 493,000 devices had been infected with Mirai malware, nearly double the number infected last month.

Mr. Allen added that Dyn was collaborating with law enforcement and other internet service providers to deal with the attacks.

In a recent report, Verisign, a registrar for many internet sites that has a unique perspective into this type of attack activity, reported a 75 percent increase in such attacks from April through June of this year, compared with the same period last year.

The attacks were not only more frequent, they were bigger and more sophisticated. The typical attack more than doubled in size. What is more, the attackers were simultaneously using different methods to attack the company’s servers, making them harder to stop.

The most frequent targets were businesses that provide internet infrastructure services like Dyn.
“DNS has often been neglected in terms of its security and availability” Richard Meeus, vice president for technology at Nsfocus, a network security firm, wrote in an email. “It is treated as if it will always be there in the same way that water comes out of the tap.”

Last month, Bruce Schneier, a security expert and blogger, wrote on the Lawfare blog that someone had been probing the defenses of companies that run crucial pieces of the internet.

“These probes take the form of precisely calibrated attacks designed to determine exactly how well the companies can defend themselves, and what would be required to take them down,” Mr. Schneier wrote. “We don’t know who is doing this, but it feels like a large nation-state. China and Russia would be my first guesses.”

It is too early to determine who was behind Friday’s attacks, but it is this type of attack that has election officials concerned. They are worried that an attack could keep citizens from submitting votes.

Thirty-one states and the District of Columbia allow internet voting for overseas military and civilians. Alaska allows any Alaskan citizen to do so. Barbara Simons, the co-author of the book “Broken Ballots: Will Your Vote Count?” and a member of the board of advisers to the Election Assistance Commission, the federal body that oversees voting technology standards, said she had been losing sleep over just this prospect.

“A DDoS attack could certainly impact these votes and make a big difference in swing states,” Dr. Simons said on Friday. “This is a strong argument for why we should not allow voters to send their voted ballots over the internet.”

This month the director of national intelligence, James Clapper, and the Department of Homeland Security accused Russia of hacking the Democratic National Committee, apparently in an effort to affect the presidential election. There has been speculation about whether President Obama has ordered the National Security Agency to conduct a retaliatory attack and the potential backlash this might cause from Russia.

Gillian M. Christensen, deputy press secretary for the Department of Homeland Security, said the agency was investigating “all potential causes” of the attack.

Vice President Joseph R. Biden Jr. said on the NBC News program “Meet the Press this month that the United States was prepared to respond to Russia’s election attacks in kind. “We’re sending a message,” Mr. Biden said. “We have the capacity to do it.”

But technology providers in the United States could suffer blowback. As Dyn fell under recurring attacks on Friday, Mr. York, the chief strategist, said such assaults were the reason so many companies are pushing at least parts of their infrastructure to cloud computing networks, to decentralize their systems and make them harder to attack.

“It’s a total wild, wild west out there,” Mr. York said.

Hackers Used New Weapons to Disrupt Major Websites Across U.S.

Hackers Used New Weapons to Disrupt Major Websites Across U.S.

A map of the areas experiencing problems, as of Friday afternoon, according to downdetector.com.

 

SAN FRANCISCO — Major websites were inaccessible to people across wide swaths of the United States on Friday after a company that manages crucial parts of the internet’s infrastructure said it was under attack.

Users reported sporadic problems reaching several websites, including Twitter, Netflix, Spotify, Airbnb, Reddit, Etsy, SoundCloud and The New York Times.

The company, Dyn, whose servers monitor and reroute internet traffic, said it began experiencing what security experts called a distributed denial-of-service attack just after 7 a.m. Reports that many sites were inaccessible started on the East Coast, but spread westward in three waves as the day wore on and into the evening.

And in a troubling development, the attack appears to have relied on hundreds of thousands of internet-connected devices like cameras, baby monitors and home routers that have been infected — without their owners’ knowledge — with software that allows hackers to command them to flood a target with overwhelming traffic.
 
A spokeswoman said the Federal Bureau of Investigation and the Department of Homeland Security were looking into the incident and all potential causes, including criminal activity and a nation-state attack.

Kyle York, Dyn’s chief strategist, said his company and others that host the core parts of the internet’s infrastructure were targets for a growing number of more powerful attacks.

“The number and types of attacks, the duration of attacks and the complexity of these attacks are all on the rise,” Mr. York said.

Security researchers have long warned that the increasing number of devices being hooked up to the internet, the so-called Internet of Things, would present an enormous security issue. And the assault on Friday, security researchers say, is only a glimpse of how those devices can be used for online attacks.

Dyn, based in Manchester, N.H., said it had fended off the assault by 9:30 a.m. But by 11:52 a.m., Dyn said it was again under attack. After fending off the second wave of attacks, Dyn said at 5 p.m. that it was again facing a flood of traffic.


A distributed denial-of-service attack, or DDoS, occurs when hackers flood the servers that run a target’s site with internet traffic until it stumbles or collapses under the load. Such attacks are common, but there is evidence that they are becoming more powerful, more sophisticated and increasingly aimed at core internet infrastructure providers.
Going after companies like Dyn can cause far more damage than aiming at a single website.
Dyn is one of many outfits that host the Domain Name System, or DNS, which functions as a switchboard for the internet. The DNS translates user-friendly web addresses like fbi.gov into numerical addresses that allow computers to speak to one another. Without the DNS servers operated by internet service providers, the internet could not operate.
In this case, the attack was aimed at the Dyn infrastructure that supports internet connections. While the attack did not affect the websites themselves, it blocked or slowed users trying to gain access to those sites.


Later in the day, Dave Allen, the general counsel at Dyn, said tens of millions of internet addresses, or so-called I.P. addresses, were being used to send a fire hose of internet traffic at the company’s servers. He confirmed that a large portion of that traffic was coming from internet-connected devices that had been co-opted by type of malware, called Mirai.

Dale Drew, chief security officer at Level 3, an internet service provider, found evidence that roughly 10 percent of all devices co-opted by Mirai were being used to attack Dyn’s servers. Just one week ago, Level 3 found that 493,000 devices had been infected with Mirai malware, nearly double the number infected last month.

Mr. Allen added that Dyn was collaborating with law enforcement and other internet service providers to deal with the attacks.

In a recent report, Verisign, a registrar for many internet sites that has a unique perspective into this type of attack activity, reported a 75 percent increase in such attacks from April through June of this year, compared with the same period last year.

The attacks were not only more frequent, they were bigger and more sophisticated. The typical attack more than doubled in size. What is more, the attackers were simultaneously using different methods to attack the company’s servers, making them harder to stop.

The most frequent targets were businesses that provide internet infrastructure services like Dyn.
“DNS has often been neglected in terms of its security and availability” Richard Meeus, vice president for technology at Nsfocus, a network security firm, wrote in an email. “It is treated as if it will always be there in the same way that water comes out of the tap.”

Last month, Bruce Schneier, a security expert and blogger, wrote on the Lawfare blog that someone had been probing the defenses of companies that run crucial pieces of the internet.

“These probes take the form of precisely calibrated attacks designed to determine exactly how well the companies can defend themselves, and what would be required to take them down,” Mr. Schneier wrote. “We don’t know who is doing this, but it feels like a large nation-state. China and Russia would be my first guesses.”

It is too early to determine who was behind Friday’s attacks, but it is this type of attack that has election officials concerned. They are worried that an attack could keep citizens from submitting votes.

Thirty-one states and the District of Columbia allow internet voting for overseas military and civilians. Alaska allows any Alaskan citizen to do so. Barbara Simons, the co-author of the book “Broken Ballots: Will Your Vote Count?” and a member of the board of advisers to the Election Assistance Commission, the federal body that oversees voting technology standards, said she had been losing sleep over just this prospect.

“A DDoS attack could certainly impact these votes and make a big difference in swing states,” Dr. Simons said on Friday. “This is a strong argument for why we should not allow voters to send their voted ballots over the internet.”

This month the director of national intelligence, James Clapper, and the Department of Homeland Security accused Russia of hacking the Democratic National Committee, apparently in an effort to affect the presidential election. There has been speculation about whether President Obama has ordered the National Security Agency to conduct a retaliatory attack and the potential backlash this might cause from Russia.

Gillian M. Christensen, deputy press secretary for the Department of Homeland Security, said the agency was investigating “all potential causes” of the attack.

Vice President Joseph R. Biden Jr. said on the NBC News program “Meet the Press this month that the United States was prepared to respond to Russia’s election attacks in kind. “We’re sending a message,” Mr. Biden said. “We have the capacity to do it.”

But technology providers in the United States could suffer blowback. As Dyn fell under recurring attacks on Friday, Mr. York, the chief strategist, said such assaults were the reason so many companies are pushing at least parts of their infrastructure to cloud computing networks, to decentralize their systems and make them harder to attack.

“It’s a total wild, wild west out there,” Mr. York said.

The Clinton and Trump Foundations Are Vastly Different. Here’s How.

The Clinton and Trump Foundations Are Vastly Different. Here’s How.

The Trump and Clinton campaigns have traded barbs and accusations about each other’s charitable foundations. The two foundations differ widely in size, purpose and the reach of their charitable work.
Donald J. Trump with his three oldest children, who serve as unpaid directors of his foundation, at the opening of a Trump HOTEL in Toronto in April 2012.

Hillary and Bill Clinton at the opening plenary session of the Clinton Global Initiative on Sept. 22, 2014.

What Do the Foundations Do?

The Clinton Foundation

The Clinton Foundation sponsors programs in public health, economic development, women’s rights and climate change. Much of its work has been praised, including efforts to lower the price of AIDS medication and distribute it to children.
But the foundation hasn’t always succeeded. In Haiti, its signature project after the 2010 earthquake — the Caracol Industrial Park — has provided only a fraction of the job promised, and those are low paying.

The Trump Foundation

The Trump Foundation is more traditional in that it directs charitable donations to causes selected by the Trump family.
Mr. Trump has sent some of his foundation’s biggest checks to the United Way, the American Cancer Society and NewYork-Presbyterian Hospital. He has also made donations to police unions, conservative advocacy groups and the personal foundations of famous athletes.


How Large Are the Foundations, and Who Funds Them?

The Clinton Foundation

The Clinton Foundation is a giant among world charities, raising an estimated $2 billion through 2016 and employing around 2,000 people. According to Bill Clinton, the foundation and the Clinton Global Initiative have helped more than 435 million people in 180 countries.
The Clinton Foundation is largely funded by third parties (including foreign governments), other major foundations and billionaire admirers of the foundation’s work.

The Trump Foundation

Mr. Trump’s foundation is modest in size, with no paid staff and a board that is composed of Mr. Trump, his three oldest children and the Trump Organization’s chief financial officer. The Trumps estimate that they each spend half an hour a week on foundation work. Mr. Trump has donated $5.4 million to his foundation over the years, according to tax filings.
Until the 2007 housing market crash, the foundation was primarily funded with Mr. Trump’s money. Since then the foundation has been funded mostly by other people's donations, which is unusual for a family foundation.