Summarize the points made in the lecture you just heard, explaining how they cast doubt on specific points made in the reading.

The reading and the lecture are both about different theories that cause big explosions in the Tunguska region of Siberia, Russia. The author of the reading believes that it was a methane gas explosion. The lecturer casts doubt on the claims made in the article thinking that the explosion was caused by an asteroid above the Earth and it entered our atmosphere. To begin with, the reading passage states that if an asteroid hit our planet, there must be significant amounts of nickel and iridium in the rock, while there is no evidence to prove it. The lecturer counters by insisting that there are eyewitnesses that saw a large bright in the sky close to the Earth, and after that, there was a huge explosion accompanied by strong winds. Second, the reading makes the argument that trees with dead branches and bark are evidence of methane explosion. He also says that an asteroid strike must cause a big crater that researchers could not find. The professor, on the other hand, points out that the asteroid exploded before it hit the ground, so scientists could not find any crater. Furthermore, laboratory tests by the Russians showed similar patterns of tree decay, which means that trees lost their branches and bark, but were still standing. Finally, although the reading mentions that the presence of a high concentration of methane gas originating from rivers, marshes, and peat bogs caused methane gas explosions and annihilate many trees, the speaker assertion that methane gas explosion would require a significant amount of gas, which was not enough in the area. Also, if this gas explosion had occurred, a fire should have been reported near it, as the eyewitnesses did not report a fire in the forest.
Submitted by mohadese mohammadi on
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