Could one leave Vladivostok by air at 8 a.m. and land in Moscow at 8 a.m. on the same day? I'm not talking through my hat. We can really do that.

The answer lies in the 9-hour difference in Vladivostok and Moscow zonal times(just like India and US are in different zonal times). If our plane covers the distance between the two cities in these 9 hours, it will land in Moscow at the very same time at which it took off from Vladivostok. Considering that the distance is roughly 9,000 kilometers, we must fly at a speed of 9,000:9 = 1,000 km/hour, which is quite possible today.

Outrace the Sun

To "outrace the Sun" (or rather the earth) in Arctic latitudes, one can go much more slowly. Above Novaya Zemlya, on the 77th parallel, a plane doing about 450 km/hour. would cover as much as a definite point on the surface of the globe would cover in an identical space of time in the process of the earth's axial rotation.

If you were flying in such a plane you would see the sun suspended in immobility. It would never set, provided, of course, that your plane was moving in the proper direction.

Outrace the Moon

It is still easier to "outrace the Moon" in its revolution around the earth. It takes the moon 29 times longer to spin round the earth than it takes the earth to complete one rotation. So any ordinary steamer boat making 15-18 knots (1 knot = 1.852 km/hour) could "outrace the Moon" oven in the moderate latitudes.

Mark Twain (a writer) mentions this in his Innocents Abroad. When sailing across the Atlantic, from New York to the Azores "... we had balmy summer weather, and nights that were even finer than the days. We had the phenomenon of a full moon located just in the same spot in the heavens at the same hour every night. The reason for this singular conduct on the part of the moon did not occur to us at first, but it did afterward when we reflected that we were gaining about twenty minutes every day, because we were going east (moon rotates from west to east around earth) so fast we gained just enough every day to keep along with the moon. "

Wednesday, August 12, 2015

What is meteor shower ?

Tuesday, July 28, 2015

Can we make it to Mars ?

Tuesday, July 21, 2015

Racing against time

Monday, July 13, 2015

Oh "my", Universe !

1. This is the Earth! This is where you live.

2. And this is where you live in your neighborhood, the solar system.

3. Here’s the distance, to scale, between the Earth and the moon. Doesn’t look too far, does it?

4. THINK AGAIN. Inside that distance you can fit every planet in our solar system, nice and neatly.

5. But let’s talk about planets. That little green smudge is North America on Jupiter.

6. And here’s the size of Earth (well, six Earths) compared with Saturn:

7. And just for good measure, here’s what Saturn’s rings would look like if they were around Earth:

8. This right here is a comet. We just landed a probe on one of those bad boys. Here’s what one looks like compared with Los Angeles:

9. But that’s nothing compared to our sun. Just remember:

10. Here’s you from the moon:

11. Here’s you from Mars:

12. Here’s you from just behind Saturn’s rings:

13. And here’s you from just beyond Neptune, 4 billion miles away.

14. Let’s step back a bit. Here’s the size of Earth compared with the size of our sun. Terrifying, right?

15. And here’s that same sun from the surface of Mars:

16. But that’s nothing. Again, as Carl once mused, there are more stars in space than there are grains of sand on every beach on Earth:

17. Which means that there are ones much, much bigger than little wimpy sun. Just look at how tiny and insignificant our sun is:

18. Here’s another look. The biggest star, VY Canis Majoris, is 1,000,000,000 times bigger than our sun:

19. But none of those compares to the size of a galaxy. In fact, if you shrank the sun down to the size of a white blood cell and shrunk the Milky Way galaxy down using the same scale, the Milky Way would be the size of the United States:

20. That’s because the Milky Way galaxy is huge. This is where you live inside there:

21. But this is all you ever see:

22. But even our galaxy is a little runt compared with some others. Here’s the Milky Way compared to IC 1011, 350 million light years away from Earth:

23. But let’s think bigger. In JUST this picture taken by the Hubble telescope, there are thousands and thousands of galaxies, each containing millions of stars, each with their own planets.

24. Here’s one of the galaxies pictured, UDF 423. This galaxy is 10 BILLION light years away. When you look at this picture, you are looking billions of years into the past.

25. And just keep this in mind — that’s a picture of a very small, small part of the universe. It’s just an insignificant fraction of the night sky.

26. And, you know, it’s pretty safe to assume that there are some black holes out there. Here’s the size of a black hole compared with Earth’s orbit, just to terrify you:

So if you’re ever feeling upset about your favorite show being canceled or the fact that they play Christmas music way too early — just remember…

This is your home.

This is what happens when you zoom out from your home to your solar system.

And this is what happens when you zoom out farther…

And farther…

Keep going…

Just a little bit farther…

Almost there…

And here it is. Here’s everything in the observable universe, and here’s your place in it. Just a tiny little ant in a giant jar.

Oh man !