The last day of the school holidays and it’s already hard to remember why.

In the morning, as everyone goes to school, a huge number of students are up.

But the sun’s already set, so the lights in classrooms go out.

Everyone is asleep.

So is everyone else.

It is a phenomenon called ‘tuttle lighting’, which has been happening across India since 2013.

The effect is to create a virtual atmosphere of darkness for students and staff.

Students, for instance, sit on their laptops in their classrooms and watch the screen, while staff in the schools can’t get enough sleep to work.

In the absence of a clear, natural daylight, the lights turn on and off and disappear.

This ‘tweeting out of darkness’ can be seen in other countries too, including in China.

A study by the National Institute of Standards and Technology (NIST) found that a tweet of an image of the sun or stars, with a caption that said: “I have been awake for nearly 24 hours.

The sun is shining” was retweeted nearly 3 million times, and it created a virtual lighting effect in classrooms.

It’s a tricky concept to explain.

But when the sun is out, it can be a bit of a nightmare, with people unable to focus on anything but staring at the screen.

“It’s just a really, really, very dark room,” said Dr Kailash Kumar, head of the Centre for Visual Science at the University of Waterloo in Canada.

The effect of tweeting out of the darkness can have dire consequences.

When the lights go out, students and their families will find themselves in a room they never knew existed, unable to see or hear their friends, or anyone else in the room.

This, in turn, can cause mental health problems, including depression and anxiety, said Dr Kumar.

While tweets can create a feeling of darkness, it is not clear how this affects the brain.

And the NIST study didn’t find any direct effects on brain functioning.

“There are no direct effects in humans,” said John Kavanagh, a professor of electrical engineering at the Institute of Electrical and Electronics Engineers (IEEE) in Melbourne, Australia.

“But it’s a very powerful thing when you have that feedback loop, when you see something like this, that you see that it’s creating an environment where you’re not thinking straight.

So you start to lose control.”

For instance, the tweet can be helpful in getting students to focus, and the effect is likely to last for a while, said Professor Kavanah.

It could also be a way to get students to feel safe during the school holiday.

“You might think about it as a way of giving them something to do, to do something for themselves,” he said.

“The effect could last for weeks.

The tweet could last longer.”

But Twitter does have some other positive aspects.

It is used by many organisations and individuals, including universities.

It also has a big social impact, helping to promote learning and social interaction.

It has even become a tool for celebrities to promote their businesses and products.

The NIST data also found that the effect was less severe in the evening, when the students are tired, distracted and focused on their screens.

It was also much less noticeable in students who were able to concentrate on the task at hand.

“There’s no way to control the effect, and that’s the problem,” said Professor Kumar.

“The only way to prevent it is to have clear lighting.”

Dr Kumar said Twitter’s power could be harnessed for a number of different purposes, including education and social change.

For instance:Teachers in schools could use the power to make sure students are focused on the work they are doing, or make sure their students can stay awake for a longer period of time during class time.

The power could also help teachers and staff in other schools and colleges to improve their learning environments, as well as improve staff morale and improve efficiency.

Teachers could also use it to improve students’ self-esteem.

If teachers or staff were able for instance to have a quiet time during the day and have a private space to do homework or play with their children, they could feel more confident.

“I think we need to have some kind of a ‘virtual space’ where we can work from,” said Kavanag.

The light effect may have a negative impact on some children and their parents.

“I think it’s quite a difficult thing to take away, because they can’t control their surroundings,” said Mr Rajkumar.

But Dr Kumar said that for many people, tweets could be a useful tool to get a sense of what they are up to during the time of the year.

“We’re not just looking at what the sun was doing, we’re also looking at how we are feeling and what our day is like,” he added.

“That’s really important for understanding yourself and the world around you.”