内容摘要：Using super-cold liquid hydrogen is “extraordinarily difficult, and we can barely do it for a few minutes right now. And here we’re talking about doing it safely for hours,” Sachdeva said.

Using super-cold liquid hydrogen is “extraordinarily difficult, and we can barely do it for a few minutes right now. And here we’re talking about doing it safely for hours,” Sachdeva said.

No reporters from The Associated Press, Bloomberg or Reuters were on the plane, where presidents often take questions from traveling members of the press.“Their reports are distributed quickly to thousands of news outlets and millions of readers throughout the world every day, so all have equal access to coverage of the presidency,” the White House Correspondents’ Association said in a statement. “This change is a disservice to every American who deserves to know what their highest elected leader is up to, as quickly as possible.”

The White House has beenwith the AP, after the news service was blocked from covering smaller “pool” events when it decided not to change the name of the Gulf of Mexico to Gulf of America, as Trump had called for in an executive order.In response to a ruling in that case, the White House instituted a

that lumped the wire services in with print reporters in a rotation for space on Air Force One or Oval Office events. A Reuters reporter accompanied the president when he traveled to Pope Francis’ funeral.White House press secretary Karoline Leavitt did not return messages seeking comment.

WASHINGTON (AP) — A Republican state lawmaker from Maine appealed to the

on Wednesday after she was censured by the state House for a social media post about a transgender athlete, a move that comes amid sparring over the issue between the Democratically controlled state and the Trump administration.The first and most frequent natural suspect is the sun. The sun is what warms Earth in general providing about 1,361 watts per meter squared of heat, year in year out. That’s the baseline, the delicate balance that makes Earth livable. Changes in energy coming from the sun have been minimal, about one-tenth of a watt per meter squared, scientists calculate.

But carbon dioxide from the burning of fossil fuels is now trapping heat to the level of 2.07 watts per meter squared, more than 20 times that of the changes in the sun, according to the U.S.Methane, another powerful heat-trapping gas, is at 0.5 watts per meter square.

The sun’s 11-year cycle goes through regular but small ups and downs, but that doesn’t seem to change Earth’s temperature. And if anything the ever so slight changes in 11-year-average solar irradiance have been shifting downward,with the space agency concluding “it is therefore extremely unlikely that the Sun has caused the observed global temperature warming trend over the past century.”