miércoles, 21 de diciembre de 2016

Seeds do not germinate with high acetic acid concentrations

Some days later we have realised that seeds do not germinate with high concentrations of acetic acid. So we decided to prepared news solutions with 0,5% and 0,1% of acetic acid. Only some lentil plants have germinated in solutions with acetic acid 0,1%. You have the results in this table.

We have made more experiments. We have transferred seeds treated with high concentrations of acid to water. And these seeds are not able to germinate five days later. In conclusion, acid damages seeds permanently.

With our control plates we have made two sets with three plants. All al the plates had small lentil plants. One of these set has been irrigated with acetic acid 0,1%; the other one with pure water. We are going to study differences in the growing of lentils plants.

viernes, 16 de diciembre de 2016

Our results, 16th December 2016

Today we have observed that no seeds have germinated in acid media. Almost all the seeds grew only in water have grown. You can see the result in the table below.
We are going to study if the damage caused by acid is permanent. So we have removed the acid and put the seeds into water and we are going to study if they can germinate next week.
We have a lot of small plants. We have divided them in two groups. One will be irrigated with water. The other one will be watered with a solution of acetic acid 1%, simulating acid rain. Next week we will see if there is any effect on the leaves and growth of the plants.

jueves, 15 de diciembre de 2016

Seeds are germinating

Now we have our first results. Almost all the control seeds, those watered, with water have germinated. On the contrary, no seeds have germinated in acid media. We will have to wait to the next days. 

In the second experiment, seeds have germinated and we can see the small plants in the pots. When they grow, half of them will be treat with an acid solution remembering acid rain. 
So, we can have our first conclusions. Would you mind to write them as comments?

miércoles, 14 de diciembre de 2016

Our experiments with acid rain

You know that rain is an important part of the water cycle. Rain is also very important for life; all living beings need water to live, even people, and rain brings us the water we need. But rain can be dangerous in some parts of the world because of pollution of the air. This rain is what we know as acid rain.
Acid gases are produced when fossil fuels are burned. But nature can also produce this kind of gases in volcanoes. When they mix when the water in clouds it can cause rain to become acid. Lemon juice, vinegar are acids; and sometimes rain is as acid as lemon juice.
Acids can be harmful. If there is too much acid in soil, seeds will not germinate and plants will not grow. Leaves affected by acid rain cannot make photosynthesis.
So, we are going to study the effect of acid rain in plants in our laboratory. We are going to prepare two experiments. In the first one we are going to study the effect of acid rain on the germination of lentil seeds. We are going to prepare some Petri dishes with 16 seeds. We are going to add only water to five of them; we will add different solutions of acetic acid in water to the rest. We will study the germination of seeds in every plate for a time.
In the second one we are going to grow lentil plants until they have leaves. Half of the plants will be watered with fresh water; the rest will be irrigated with a solution of acetic acid. We will study differences between these two treatments. In our blog we will post pictures with our results. Please, contribute to our research with comments.
(Spanish version)

And our first results

Two days after the beginning of our experiment, we have our first results. Two seeds have germinated in control plates. No seed have germinated in plates with acid solutions. Here you have a picture of these plates.

miércoles, 23 de noviembre de 2016

The water cycle

You know that the water on our planet is in constant movement. For example, water goes from seas to clouds, and from clouds to the surface of our planet. This movement is what we know as the water cycle.
The water cycle is the process in which the Earth's water moves between the hydrosphere, the atmosphere, the geosphere and the biosphere.
This is possible thanks to the energy our planet receives from the Sun and the gravitational pull. Heat causes water to change the state; gravity moves water from higher points to lower ones, in the seas. Here you have a picture with the cycle water.

The water cycle (from USGS).

Here you have a link to an interactive diagram about the water cycle.
Here you can study the water cycle in Spanish.

And finally, an activity. Fill the gaps in this diagram with the processes of the water cycle. You can download the diagram from here.

jueves, 20 de octubre de 2016

About solar eclipses

In these days, we are learning about eclipses in our classes. In my opinion, all of you have understood the relative positions of the Sun, Earth and Moon, both in solar and moon eclipses. So, you should be able to explain what is an eclipse, the different types of eclipses and the differences between total and partial ones.
And as you have asked to me about next solar eclipses, here you have information about those visible from Granada in coming years:
Monday, 21st August  2017 (Partial, 6,3%).           
Thursday, 10th June 2021 (Partial, 1,4%).
Saturday, 29th March 2025 (Partial, 16,3%).
Wednesday, 12th August 2026 (Partial, 95,7%).
Saturday, 6th February 2027 (Partial, 0,5%).
Monday, 2nd August 2027 (Partial, 99,3%). 
Wednesday, 26th January 2028 (Annular, 82,6%).
And here you have a short documentary that we made about the solar eclipse we watched from this school two years ago.
I would like to know your opinion. Please write a comment in English.

jueves, 13 de octubre de 2016

What has happened with the horoscope?

In ancient times, people believed that the Earth was the center of the Universe and the Sun rotated around our planet. Today we know that the Sun is in the center of the Solar System and every planet orbits our star. They also observed the sky and connected the stars with lines drawing pictures known as constellations. They were convinced that those constellations were important symbols telling stories about their gods and myths and were very useful in order to know about people personality  and predict their future too.
The ecliptic. By Tauʻolunga - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=935439
As a result of the motion of the Earth around the Sun, our star appears to pass in front of different constellations. This apparent path of the Sun on the celestial sphere marks the ecliptic; the constellations through which the sun passes define the zodiac. Consequently, all the zodiac constellations lie along the ecliptic.
Babilonians, about 3.000 years ago, had a 12 month calendar, so they decided to divide the zodiac into twelve equal parts. For them, there were twelve zodiac constellations and this is the origin of the twelve signs listed in the horoscope that everybody knows. For example, if you were born under the sign of Leo, it means that the Sun was in this constellation in that moment and, of course, every year at your birthday.
But... is it true? Recently some newspapers said that NASA have changed the astrological signs for first time in 2000 years; consequently, lot of people now have a different zodiac sign. In my opinion, this is not a great problem for people who don't believe in horoscope, but what happens with the other people? Has their luck changed? 
I think that this is a very interesting matter that we can investigate. An to begin with, just some easy questions:
What do you know about zodiac? What is your zodiac sign? Can the stars really predict the future or describe what are people like based on their birth date? Please, write your answers as a comment.
(Spanish version)