Southeastern Louisiana University, Elaine, Ira Plato discussed on Science Friday
In many places in the triple. Digits can't get too hot for planes to fly. My next guest says yes red. Elaine is associate professor of physics at southeastern louisiana university and a popular dot physics blogger at wired science blogs read. Welcome back to science friday. Thank you. Let's get right into this. Because i remember reading a piece. He wrote back in two thousand seventeen a heatwave back then describing how it can get too hot for airplanes to take off. Tell us why that is. I mean i was surprised to. I saw that. And i'm like what that's weird But it is true when when the weather gets too hot some of these planes can't take off it has to do with the way that planes fly when the plane wing flies at in it's tilted at some angle. It collides with these molecules these than change momentum in because they change momentum they push on on the wing so if you think of a plane flying and is pushing through the air and deflecting these air molecules down this produces an upward thrust on the plane and it explains how the plan comply. I like that way better. 'cause it's fundamental physics more physics. It's like a rocket ship. Air goes down plane goes up. It's exactly like a rocket ship. That's right so what happens when the air gets too hot there. Well when the arrogance hot you know what what is hot air. We like to think of Temperature as associated with the motion of the particles in the air. The nitrogen molecules in the auction molecules. And as you increase the temperature these molecules move faster and faster and faster and when they do that they spread out so you decrease the density of the air when it's hot and doesn't feel that way but that is true this lower density air with higher temperature and that means there's fewer of these air molecules to collide with the wing and you get lower lift with lower density air. You could compensate for that by flying faster but that would take a longer runway. And then that's where we get into a safety issue for some point there does not. They don't have a long enough runway to make sure that they can get to take off speed and so there you just have to wait till it gets cooler before you can take off. Yeah someone told me that. A lot of flights into las vegas in december are morning and evening. Because it's not so hot. It's if it's too hot in the middle of the day than a lot of these planes just don't have the safety clearances to take off you know. I didn't hear any reports of mass groundings of airplanes. This really hot week. We've been having Do you expect this to happen sooner or later. Oh yeah as we deal with hotter and hotter temperatures. You have an option of either changing planes. Someplace can take off with that or getting along the runway but both of those aren't really easy to change real quick. It's easier just to ground the plane. Wait till it's safe to fly again. You know we always hear about the unexpected consequences of climate change and what things are going on about plants and and he and hurricanes but we never think about effecting the airline industry right and we depend on that a lot. In general we fly a lot and we travel a lot by plane because this lot quicker than cars and then it is a problem so we need to address climate change but we probably also need to address airline travel. It's not necessarily always the best mode. high-speed trains would wouldn't have this problem. I'm with you on that one. Let's let's see if we can get more of them to cross the country. Yeah i'd like that too. Yeah well thank you for explaining the physics of flight right. Thank you read. Elaine is an associate professor of physics at southeastern louisiana university and a popular dot physics blogger at wired science blogs. We're gonna take a break and when we come back. The delta variant is spreading. Is it time to bring back masks. Get more people vaccinated. All of the above will be back to fact. Check your feed after this break. Stay with us. Decades before motown there was black swan records. America's first black owned record label. It was founded by a maverick who fought for equality. Lifted up black voices and then mysteriously disappeared. The vanishing harry pace is a story of hidden identities any phenomenal but forgotten man. Who transformed our world. Listen on the radio app. Feed on apple podcasts. This is science friday. i'm ira plato. It's been six months since the first variant of copied nineteen raised alarm bells around the world. Now one variant above all others seems to be spreading rapidly. I'm talking about the delta variant. I identified in india and then now has spread to more than eighty countries south africa australia. Germany and other countries are reimposing limits on travel and daily life and israel where more than sixty percent of people are vaccinated has reinstated mask requirements. In fact the world health organization is recommending that all fully vaccinated people continue to wear masks and los angeles county advised everyone to wear masks indoors in public places even if fully vaccinated. What does that mean for you here to help us take the temperature of the delta variant and other covert nineteen news is angela rasmussen research scientists that veto interact the university of saskatchewan's vaccine research institute in saskatoon says. Catch one welcome back. Thanks for having me back ira. We've talked about the variants. Before but this delta variant is really making the rounds i mean the dominant variant of the virus in many countries the twenty percent of cases in the us that variant. Do we know why it's so contagious. So we we really don't it could be that people are remaining contagious for a longer period of time it could be that the virus is better at binding. Its receptor ace to And infecting cells that's called insect activity. It could be that The virus is just making more virus and shedding more infectious virus thereby increasing the odds that you will be infected if you're exposed to somebody who is infected as well so we we really don't know but to me the epidemiology. Data's quite clear that this virus does spread Quite easily particularly among unvaccinated or partially vaccinated people and for that reason it is Rightfully a big concern and we still don't know if it's more likely to cause serious illness. That's something that i think is very very difficult to try to figure out. With epidemiologic data human populations in populations of unvaccinated or partially vaccinated. People are going to be different in every community and in every place where the delta variant might be spreading and if you end up seeing an increase in people going to the hospital relatives to other variants it could be just that different. People are getting infected people with other risk factors but because it's infecting more people. It appears that it is more pathogenic or virulent. So that's something that's still remains to be seen in. There are studies trying to get to the bottom of this but to me the take home message for everybody is really clear. You should get fully vaccinated because full vaccination does provide a strong protection against the delta variants. And i think that's what we're seeing in israel where the vaccination rates are high. There are a significant number of their cases and vaccinated people. But they're not serious illnesses. That's exactly right so this is one thing that's really frustrating about some of the media coverage about this people talk about all these breakthrough infections happening in fully vaccinated people. But they don't mention that the people who are actually in the hospital are largely unvaccinated or partially vaccinated people the people who are fully vaccinated may test positive for the virus. They may have transient abortive infections. And this actually normally happens with many other vaccines that are very very effective But the vaccines are holding their own against the delta variant. And that is that. They're protecting people even people with breakthrough infections from becoming seriously ill from going to the hospital and from dying. So what should people do. They heard the w. h. o. Should i keep my mask on how. How should i make that decision. Will you know. I think this is something that that were all sick. A wearing masks and that can't be under. Estimated mass can be uncomfortable especially in hot weather but masks are a relatively easy. Non-pharmaceutical intervention to apply. Certainly there are a lot better than closing down businesses or telling people to stay home. Many of the breakthrough infections vaccinated people in a few cases. There has.