[English]
Welcome to Learning English,
a daily 30 minute program
from the Voice of America.
I'm Caty. Weaver.
And I'm Mario Ritter Jr.
This program is designed
for English learners.
So we speak a little slower,
and we use words and phrases,
especially written for people learning
English.
On today's program, John Russell reports
on unmanned aircraft for agriculture.
Jill Robbins has a story about an ancient,
bird like animal.
Bryan Lynn tells about the Voyager
spacecraft on the science report,
then wishing on lesson of the day.
But first.
American companies are developing
unmanned aircraft systems
that are larger than drones.
The goal is for the aircraft
to help agricultural producers
and reduce risks to human safety.
When Hector Xue was learning
to pilot a helicopter in college,
he remembered having a few bad experiences
while flying at night.
The experiences led him
to research unmanned aircraft systems
while getting his doctorate
at Massachusetts Institute of Technology.
Then, Xu formed Rotor Technologies in 2021
to develop unmanned helicopters.
Roder has built two autonomous helicopters
that the company calls Spray Hawks.
Roder aims to have as many as 20
spray hawks ready for market next year.
The company also is developing
helicopters that would fly shipments
into disaster areas
and to oil rigs in oceans.
The helicopters could also be used
to fight wildfires.
For now, Roder
is paying attention to agriculture.
The industry has accepted automation
with drones, but sees unmanned helicopters
as a better way to spray larger areas
with pesticides and fertilizers.
A major appeal of automation
in agriculture flights is safety,
because special airplanes, called crop
dusters, fly at around 240km/h
and only about three meters off
the ground.
There are tens of accidents each year.
The small planes hit power lines,
cell towers and other planes.
Older planes in disrepair and pilot
tiredness play a part in accidents.
2014 report from the
National Transportation Safety Board found
there were more than 800 agriculture
flight accidents
between 2001 and 2010,
including 81 that were deadly.
A separate report from the National
Agriculture Aviation Association
found nearly 640 accidents from 2014
until this month, with 109 deaths.
It is a very, very dangerous profession,
said Dan Martin,
a research engineer with the US Department
of Agriculture's
Agriculture Research Service.
Martin said about the pilots,
they make all their money in those short
few months.
So sometimes it may mean that they fly
10 to 12 hours a day or more.
Job risks also include possible contact
with farming, chemicals in recent years.
Safety and cost concerns
have led to a number of drones
flying above farmers fields, Martin said.
He added that some 10,000 drones
will likely be sold this year alone.
It's growing exponentially as a market
super fast, Martin said.
But the size of the drones
means they only can cover
a small amount of the area
that a plane or helicopter can.
The limitation is
providing an opening for companies
building bigger unmanned aircraft
like Rotor and another company, Pica.
California based Pica announced in August
that it had sold its first
autonomous electric aircraft
for crop protection,
and to a buyer in the United States.
Pikas.
Pelican spray,
a fixed wing aircraft, received
official approval last year
to fly for crop protection.
The company also sold its Pelican
spray to Dole for use in Honduras
and to the Brazilian company SLC Agricola.
Lucas Coke is chief technology officer
at Hainan Brothers Agro Services.
The company
which but the Pelicans prey in August.
Coke has called unmanned aircraft
part of a coming revolution
that will save farmers
money and increase safety.
The Kansas based company operates
out of airports
from Texas to Illinois.
Coke does not see the unmanned aircraft
replacing all the company's pilots,
but rather taking over the riskiest jobs.
The biggest draw
is taking the pilot
out of the aircraft inside
of those most dangerous situations, cook
said.
But Coke
also says that autonomous aviation systems
could bring new dangers
to an already busy airspace.
Still, the risk is
less of a concern in rural areas,
with plenty of open space
and fewer people.
Companies like rotor have developed
their systems to work
if bad events come up.
Rotors helicopter, for example,
has a half dozen communications systems
and for now, a remote pilot in control.
If the ground team loses
contact with the helicopter,
rotor
has a system to deal with the problem.
The system makes sure
the engine can be turned off,
and the helicopter can perform
a controlled landing.
The safety measures will go a long way
to helping the company receive
what it expects
will be official government
approval to fly
its helicopters for business purposes
once the company has approval.
The difficulty, as Xu sees
it, will be building more devices
to meet the demand
in the United States and Brazil.
I'm John Russell.
The brains
of today's birds show
a level of intelligence
and behavioral complexity
rivaled only by mammals.
But scientists do not fully understand
how bird brains have changed
over millions of years from the form
they had as dinosaurs.
That understanding is now growing
thanks to a fossil discovery in Brazil.
Researchers unearthed the remains,
or fossil, of a head, bone
or skull of a bird species
not known before
it has been named.
Another witness, Hestia.
The fossil was in such good condition
that scientists were able
to create a computer image of its brain
and inner ear structures, as
it lived in a dry area
about 80 million years ago,
during the Cretaceous period, near
the end of the age of dinosaurs.
This finding is one of a kind, said
University of Cambridge
fossil expert Guillermo Avalon,
a lead researcher of the study.
It appeared this month
in the publication Nature.
Birds
developed from small feathered dinosaurs
during the Jurassic period.
The novel Ana's Discovery
filled in a 70 million year gap
in the understanding of the development
of the bird
dating back to the earliest known bird,
Archaeopteryx.
It lived about 150 million years ago
in what is now Europe.
The researchers said
the novel Ana's Skull has a bill
and is shaped like modern birds.
Its brain shows
both modern and ancient elements,
and some that are in between.
Luis Chiapas
is a fossil scientist
at the Natural History Museum of Los
Angeles County in California,
and a co-writer of the study.
He said scientists
rarely find such skulls of early birds,
and this one is the best preserved ever.
Daniel Field is a fossil scientist
at the University of Cambridge
and the study's lead writer.
He said scientists have long struggled
to understand how
and when the brains
and intelligence of birds developed.
The field has been awaiting
the discovery of a fossil
exactly like this one.
He said
the novel Ana's brain,
measuring about ten millimeters
across, is smaller relative to skull size
than that of modern birds,
but the skull is larger
and more complex
than that of Archaeopteryx.
Its cerebellum, a brain structure
that in living birds
helps with motor control during flight,
was smaller than in today's bird species
and more like Archaeopteryx is,
but its brain was connected
to the spinal cord
in a way
similar to modern birds as well as humans.
It was unlike Archaeopteryx
and the dinosaurs
from which birds evolved.
Nervousness also had something special
its inner ear organ for
balance is larger than in any other known
bird.
The fossil included 80%
of the birds bone structure or skeleton.
The scientists say
they believe the bird could fly well
based on their examination of the remains.
Field said, if you gave it a quick look,
you might think it was like a living bird.
But a closer look would show you
some important differences,
like claws coming out of its wings.
I'm Jill Robins.
NASA has once again reconnected
with its Voyager spacecraft,
marking a continuous portion
of the American space agency's
longest mission in history.
The two spacecraft, Voyager
one and Voyager two,
launched
within weeks of each other in 1977,
so they have been operating
for more than 47 years.
NASA officials have reported
several difficulties
with the spacecraft in recent years,
mainly communication issues.
The most recent problems involved
the Voyager one spacecraft,
NASA said in a statement in April.
It had remained out of touch
with the spacecraft
for the previous five months.
Agency officials said they later learned
the problem was linked to a chip inside
one of Voyager One's onboard computers.
The issue may data being sent
by the spacecraft unreadable.
NASA said its engineers
were able to fix that problem
by making changes to how the spacecraft
stores and reads data.
Then in October,
NASA reported another communication issue
that resulted in a brief delay
in receiving data from Voyager one.
That problem turned out to be linked
to the spacecraft's
radio transmitter system.
The agency said that
for some reason, Voyager one's fault
protection system was activated
when NASA sent a command
for the spacecraft
to turn on one of its heaters.
This activation, meant to save power,
led Voyager one to start sending signals
to a different radio transmitter system.
Then it normally uses.
This meant NASA had to listen
for the signals on the S-band
instead of the usual X-band.
Once they did this, they were able
to start receiving data again.
NASA has said the S-band is much weaker
than the X-band, so engineers were seeking
to get the X-band
radio communication system
back online for long term use.
NASA said the agency had not used
the S-band since 1981.
Voyager one and Voyager two are NASA's
most distant operating spacecraft.
The agency has reported
Voyager one is exploring space
from about 24,000,000,000km from Earth,
while Voyager two is operating
from about 20.5 billion kilometers away.
Because of this great distance,
NASA says its communication
with the two Voyagers
takes about one day to receive data
and another day
to send information back from Earth.
The two Voyagers were first
designed to explore Jupiter and Saturn.
Both spacecraft successfully
carried out studies of those planets.
Later, Voyager two made the first ever
close observations of Uranus and Neptune.
In 1989.
The two spacecraft
then began a new mission
to explore distant areas of space.
In 2013, NASA
announced Voyager
one had crossed over the border
dividing our solar system
from Interstate stellar space.
The term interstellar means between stars.
Scientists say interstellar
space begins where the sun's continuous
flow of particles
and its magnetic field stop.
Voyager two first entered
interstellar space in 2018.
NASA said
the spacecraft was more than 17.7
billion kilometers
from the sun at the time.
Both Voyagers are the only spacecraft
so far
to explore interstellar space.
The space agency says
the Voyagers are studying
how the interstellar medium interacts
with the solar wind.
Solar wind is the continuous flow
of charged particles released by the sun.
The spacecraft have also provided
data on the heliosphere,
a kind of protective bubble
around our solar system.
Suzanne
Dodd is the current project manager
for the Voyager mission at NASA's Jet
Propulsion Laboratory in California.
She recently said in a statement
the agency has no plans
to retire the two Voyagers
as long as they are communicating
with mission
members back on Earth.
Dodd said the spacecraft
are currently centered on observing
how interstellar space and the heliosphere
interact with each other.
We wouldn't be doing Voyager
if it wasn't taking science data,
she added.
Dodd noted one reason
the Voyagers have been operating
for so long
is that the engineers who built them
provided multiple backup systems
to avoid future problems.
She said some who worked on Voyager
in its earliest days
have even come back from retirement
to pass on knowledge
to the next generation
of scientists and engineers.
From where I sit as a project
manager, it's really very exciting
to see young engineers
be excited to work on Voyager, Dodd said.
To take on the challenges
of an old mission and to work side by side
with some of the masters,
the people that built the spacecraft.
They want to learn from each other.
I'm Bryan Lynn.
Welcome to the
lesson of the day
on the Learning English Podcast.
My name is Andrew Smith.
And my name is Jill Robins.
Thanks for joining us.
Today's lesson will help
you learn more about the English you hear.
In our video series, let's Learn English.
The series shows animate Teo
and her work and life in Washington, D.C..
Here's Ana introducing herself.
Hello.
My name is Ana Mateo.
In our previous lesson of the day,
we heard Ana and her friend Bruna
talk about hopes and wishes.
In today's podcast lesson, we're
going to give you more ways to practice
using the verb wish.
But first, let's listen to Ana
and Bruna again.
This is from lesson ten of level
two of the Let's Learn English series.
Hi, Ana.
Hi, Bruna.
What's up?
I thought we could meet for lunch today.
I wish I could, but I can't.
I have to research Peru for a story.
How's it going? Not so good.
I've been reading about Peru
and listening to Peruvian music.
I really want to understand Peru.
I hope it's enough.
We wish for things
we can't do, have or be.
That means we wish for things
that are different
from how things are now.
To show this difference, English changes
the form of the verb or modal that follows
the word wish, for example, can change
this to could have changes to had
is changes to were
was, changes to had been, and so on.
So it sounds like this.
I wish I could.
I wish I had.
I wish I were. I wish I had been.
Of course,
those are not complete sentences.
So now we'll explain how you can practice
making sentences with the word wish first.
Right?
Or think of a sentence that describes
a real situation in the present
or in the past.
Then use a sentence
with which to express the idea
that we want a different situation.
Jill and I are going
to give you some examples.
First we say one thing
and then we wish
that thing were different.
Are you ready, Jill?
Ready?
I can't swim.
I wish I could swim.
I don't understand the question.
I wish I understood the question.
My head hurts.
I wish my head didn't hurt.
Okay.
Notice that after the word wish,
we use a word that sounds like we
are talking about the past.
But we are not talking about the past.
Listen again to this example.
I don't understand the question.
I wish I understood the question.
The verb understand changes to understood.
But we're not talking about the past.
In fact,
we want to understand the question now.
But because.
Which means that it is not possible
at the present time for us to understand.
We change the verb to understood.
We could also say,
I wish I could understand the question.
This change of the verb form
also happens in conditional statements,
like sentences that start with the word.
If right.
For example, we say, if I had more time,
I would study more.
The verb had does not mean the past.
Instead, it shows a situation that is not
real because it comes after the word. If.
Okay.
Now let's give more examples with wish.
Are you ready again, Jill?
Ready?
I didn't see the game.
I wish I had seen the game.
He is not here.
I wish he were here.
I smoke cigarets.
I wish you didn't smoke cigarets.
They talk really fast.
I wish they didn't talk so fast.
Then you are not at the party.
I wish you had been at the party.
Notice that for real statements
about what people do,
we change it to negative.
When we use wish.
They talk really fast.
I wish they didn't talk so fast.
In the same way,
the negation shown by the word
not disappears
when we use wish.
I didn't see the game.
I wish I had seen the game.
Now it's your turn, listeners.
We will
say a sentence about a real situation,
and then give you time to say
a sentence using the word wish.
After you will hear us say a sentence
using the word wish
so you can compare your answer.
Are you ready?
Okay, here we go.
Sentence number one
I can't visit my family.
I wish I could visit my family.
Sentence number two.
I don't have a car.
I wish I had a car.
Sentence number three.
He is always late.
I wish he weren't always late.
Sentence number four.
They are not here.
I wish they were here.
Sentence number five.
I didn't go to the beach.
I wish I had gone to the beach.
Sentence number six.
She didn't help me.
I wish she had helped me.
Sentence number seven.
She never talks to me.
I wish she would talk to me.
Sentence number eight.
I don't know how to swim.
I wish I knew how to swim.
Listeners, how well did you do?
Was it easy or difficult
to change your sentences
and use the word wish?
There are a lot of forms to learn,
so don't worry
if you could not change all the sentences,
but you can always go back
and play the examples again
and try to save the sentences
with the word wish.
We hope these exercises will be helpful.
Now, before we finish, here's
a little chart
with more examples using the word wish.
Ready? Listen.
I can't sing, but I wish I could.
And you don't dance. But I wish you would.
You don't cook and you don't try.
I wish you would cook.
And I wish you would try.
I would
if I could, but I don't have the time.
I wish we had a much longer day.
I do too, but what else can we say?
How about this?
We wish we had more time with you.
We wish we did. You know it's true.
But it looks like time is running out.
So one more thing before we go.
We hope you'll write us
and let us know something that you wish
that we would do to help you
learn and have fun, too.
Well, we really do have to go now.
Write to us
and tell us your wishes at Learning
English at VOA News.com.
And remember, you can also find us
on YouTube and Instagram and Facebook.
I'm Jill Robbins.
Thanks for listening. I'm Andrew Smith.
And that's our show for today.
But join us again tomorrow
to keep learning
English on the Voice of America.
I'm Caty Weaver.
And I'm Mario Ritter Jr.