Here are a few impressive balloon displays.

Bristol International Balloon Fiesta

Starting in 1979, the Bristol International Balloon Fiesta in the UK is an annual balloon festival kicking off at the start of August for four days. Stealing a little bit of the attention, the RAF’s Red Arrows also squeeze in a sky performance just to keep things interesting.

Albuquerque Balloon Festival

Starting off with just 13 balloons in 1972, this 9 day-long October event now pulls in 550 balloons. That makes Albuquerque, New Mexico, home to the biggest hot air balloon festival in the world.

While you can jump in a basket any day of the week, take part in the photo contest or listen to live music, Mass Ascension days are the best ones to drop by.

Saga International Balloon Fiesta

In early November, by the Kase River in Japan, over a million people and 100 balloons touch down for the Saga International Balloon Fiesta. Going strong for over 40 years, it’s an annual showcase of the best balloon creations.

The event is entirely free and includes access to the Hot Air Balloon School where you can learn what it takes to run a balloon.

QuickChek New Jersey Festival of Ballooning

Further north at the Solberg Airport in Readington, New Jersey, you’ll find the QuickChek New Jersey Festival of Ballooning. Over the last weekend in July, it runs a schedule of live music and special shape gatherings. But not just about the balloon, this festival helps you blow off your own steam with sessions of stretch classes and a 5-kilometre run alongside the balloons too.

“Why do you always apologize before you ask a question? I don’t get it,” Dan asked. I looked at him blankly, not understanding what he meant but felt that there was more than a trace of annoyance in his tone.

I felt defensive. I thought for a moment. “There’s no reason for it, you shouldn’t do that.” he said. “Sorry if it annoys you,” I responded. I probably annoyed him again by apologizing again.

This happened over 35 years ago. I thought about it then, and I still reflect on it now. Asking questions in class or in conversation isn’t that simple, at least not to me.

As I thought about it, many things came into play. First was self-consciousness and insecurity. Maybe I had missed something the professor said. I knew some students, as a result of those doubts, didn’t ask questions.I had enough confidence to ask, but not enough to not soften it. I realized, as Dan pointed out, that I likely did start with something like, “Sorry, maybe I missed this, but can you explain...”I wondered whether there was anything so wrong with that.

I don’t think it occurred to me at the time, but it did years later, that it also probably related to being female. I knew that as a woman there was a line of not coming across too aggressively.

Besides, I became conscious of not implying judgment—I didn’t want a professor to think I was questioning their expertise, or suggesting they were a bad teacher. It seemed like a reasonable strategy to start by acknowledging that I could be wrong or uninformed.

Before Dan’s comment, I hadn’t thought about it consciously, much less considered that there could be a downside to doing it. But I was learning that there was. If Dan was any example, it could be unpleasant. I didn’t want to go around apologizing for my existence. As I’ve gotten older, I think I’ve done it less.

Noisy brothers or sisters? Loud construction right outside your window? A flexible new loudspeaker could help you rest easy. It could someday turn your walls into noise-canceling systems. And when you’re ready to liven things up, use the same wallpaper—or the surfaces of other ordinary objects in your room—to play music.

The new loudspeaker is super thin—about as thick as a few sheets of paper. It’s lightweight and flexible enough to stick to most surfaces. And you can make it big, as in wall-sized, notes Jinchi Han. He’s an electrical engineer at the Massachusetts Institute of Technology in Cambridge.

Lots of dome-shaped (圆顶状) microstructures cover the surface of the speaker. The researchers start with a thin, flat sheet of some material. Then they use pressure to pull that material through openings to create the dome shapes. When squeezed, the material they use creates an electric charge. But applying an electric field across the material will also cause the domes to expand and contract, Han explains. That can generate sound.

Han points to another benefit of this tech. Large expanses of the new material could make controlling noise a lot easier. Noise-canceling systems already exist. But whether it works for a listener depends on where that listener’s ears are in relation to the approaching sound waves.

Trying to cancel noise this way everywhere inside a room would be tricky, Han points out. It would take lots of microphones and speakers, which can be expensive.

Here, each dome works as a tiny speaker. The domes can generate sound waves in groups or individually. Wallpapering your bedroom with this material would create speakers all around you. Those same speakers also could cancel unwanted sound. When desired, you could turn any space into “a quiet zone where you could sleep or study without too much noise,” Han says. He also sees applications in cars, airplanes, apartments or anywhere unwanted noise is a problem.

Want to help butterflies? A new study suggests turning off the lights.

Light pollution at night can disturb its abilities to recognize directions, researchers have found. Artificial light can disrupt their circadian (昼夜) rhythms and affect their sense of directions. That can make the butterflies disoriented when they try to fly the next day.

“Darkness is important to butterflies since the internal circadian clock of butterflies functions normally when they are exposed to natural day-night lighting cycles,” study author Patrick Guerra, an assistant professor at the University of Cincinnati, tells Treehugger.

Monarch butterflies migrate (迁徙) by the millions each year, making the trip from northern areas of the continent to California and Mexico and back. Because most butterflies only live for a few weeks to a few months, it takes several generations of butterflies to complete the migration. But too much light at the wrong time can urge the butterflies to take off when they should be resting instead for their voyage.

“As monarch butterflies are a threatened species with their population numbers in decline, we wanted to see what types of environmental stress might be linked to their decline,” Guerra says.

For their study, researchers conducted lab studies where they reproduced the effects of artificial light pollution with butterflies using a flight simulator (模拟器).

They first tested if monarchs treated a single, artificial light source as if it were the actual sun during the day. Once they established what they did, they then tested how the monarchs would behave when exposed to this same artificial light source during their night.

Butterflies stayed quiet and unmoving when they were first placed in the flight simulator in the dark. But as soon as scientists turned on the light, they started flying. The light made them believe that night was day and this can cause them to fly longer at night or start flying too early.

“These findings demonstrate how urbanization can negatively affect important biological phenomena, and therefore allow us to understand how human activity impacts the rest of nature,” Guerra says.