Nemesis, the Sun's companion star

suppose our Sun was not alone but had a companion star. Suppose that this companion star moved in an elliptical orbit, its solar distance varying between 90,000 a.u. (1.4 light years) and 20,000 a.u., with a period of 30 million years. Also suppose this star is dark or at least very faint, and because of that we haven't noticed it yet.

This would mean that once every 30 million years that hypothetical companion star of the Sun would pass through the Oort cloud (a hypothetical cloud of proto-comets at a great distance from the Sun). During such a passage, the proto-comets in the Oort cloud would be stirred around. Some tens of thousands of years later, here on Earth we would notice a dramatic increase in the the number of comets passing the inner solar system. If the number of comets increases dramatically, so does the risk of the Earth colliding with the nucleus of one of those comets.

When examining the Earth's geological record, it appears that about once every 30 million years a mass extinction of life on Earth has occurred. The most well-known of those mass extinctions is of course the dinosaur extinction some 65 million years ago. About 25 million years from now it's time for the next mass extinction, according to this hypothesis.

This hypothetical "death companion" of the Sun was suggested in 1985 by Daniel P. Whitmire and John J. Matese, Univ of Southern Louisiana. It has even received a name: Nemesis. One awkward fact of the Nemesis hypothesis is that there is no evidence whatever of a companion star of the Sun. It need not be very bright or very massive, a star much smaller and dimmer than the Sun would suffice, even a brown or a black dwarf (a planet-like body insufficiently massive to start "burning hydrogen" like a star). It is possible that this star already exists in one of the catalogues of dim stars without anyone having noted something peculiar, namely the enormous apparent motion of that star against the background of more distant stars (i.e. its parallax). If it should be found, few will doubt that it is the primary cause of periodic mass extinctions on Earth.

But this is also a notion of mythical power. If an anthropologist of a previous generation had heard such a story from his informants, the resulting scholarly tome would doubtless use words like 'primitive' or 'pre-scientific'. Consider this story:

There is another Sun in the sky, a Demon Sun we cannot see. Long ago, even before great grandmother's time, the Demon Sun attacked our Sun. Comets fell, and a terrible winter overtook the Earth. Almost all life was destroyed. The Demon Sun has attacked many times before. It will attack again.
This is why some scientists thought this Nemesis theory was a joke when they first heard of it -- an invisible Sun attacking the Earth with comets sounds like delusion or myth. It deserves an additional dollop of skepticism for that reason: we are always in danger of deceiving ourselves. But even if the theory is speculative, it's serious and respectable, because its main idea is testable: you find the star and examine its properties.

Gilchrist confident of DC winning IPL III

Hyderabad: Defending champion Deccan Chargers captain Adam Gilchrist on Thursday expressed confidence that his team would continue its winning ways and lift the third edition of the Indian Premier League as well.
The team could not win the inaugural IPL due to some mistakes but it rectified them to win the second edition the high-profile tournament held in South Africa, he said at a promotional event here tonight.
Ahead of the start of IPL III, Gilchrist and other players of the team were in Hyderabad on a brief visit.
The team is, however, not playing in its home ground as its home matches have been shifted from Hyderabad due to the ongoing Telangana agitation.

knowing abt small facts

these r small facts but make big differences....

*frm a tap droplets going out is @50ml per min same way 3lit per hour, 72lit per day, 27375lit per year don't be neglect at these things...
*water existing in earth human beings can use only 1% of it soo bee careful at these points.....
*no need to through the e-waste like mobiles,electronic goods etc, we need to recycle all the e-waste to particular companies working on the e-waste particularly for information sign on to http://www.ecoreco.com

updates...

I'm a bit behind at getting to this blog for some irregular or regular (depending on how you look at it) updates....but I do have a somewhat good reason. It's hot season and I've been knocked on my behind for about the past week with a variation. I felt as if I was hit by a truck last week. That, along aches and the feeling of someone using ------

Concepcion, Chile (CNN)

The death toll from Saturday's 8.8-magnitude earthquake in Chile reached 795 on Tuesday, the president's office said.
Officials say the tally likely will increase in coming days as search-and-rescue crews dig into collapsed buildings and discover more bodies.
While that work continued, officials also dealt with another pressing problem: looting and lawlessness in the city of Concepcion and other areas of central and southern Chile.
Authorities said they would enforce a curfew from 6 p.m. Tuesday until noon Wednesday.
Speaking at a Tuesday morning news conference, President Michelle Bachelet said mayhem will not be allowed.
The president's comments came after another restless night in Concepcion, where looters openly ransacked stores in front of soldiers standing guard nearby and neighborhood residents have set up armed security committees.
The unrest broke out as thousands of desperate residents in southern and central Chile remained without food, water, electricity, gas and other basic services in the wake of the earthquake.
More than 13,000 soldiers were being dispatched to secure order, Bachelet said.
A CNN crew witnessed looters being arrested Tuesday and observed that more troops seemed to be patrolling Concepcion on Tuesday than Monday.

Stop Global Warming

“Stop Global Warming” is one of the biggest cause -- with over 3.5 million members. Together, we can do a tremendous amount to solve the climate crisis. But the rules about how Causes work are changing.

http://acp.repoweramerica.org/causes

We have very important fights ahead, from U.S. legislation, to international negotiations in Mexico, to defending the climate science -- so sign up now to continue to receive:

- The opportunity to join strategy conference calls with hardworking campaign staff
- Inside information on the the latest policy developments from the Alliance for Climate Protection's policy team
- The chance to be in our television ads

http://acp.repoweramerica.org/causes

Engineering life

ry {parent.deselectBloggerImageGracefully();} catch(e) {}" href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgySxOrLrrFZE_lwMz6NRjoq4LULgzt_aX8G8n0-OXa6bnPJjkf4y7clLu9SauKoapbGSCgADvqGiFrKdbPRd5MdGcPtbHdg-vTbs9QV4oLsf7Io2KHbgKTBZ_nIbATpnZ-UUEwwiKpEC8/s1600-h/DSCN0303.JPG">

My eng life goes on like a bird flying in air with all my frdzs around me and some ** birds in middle...bit hurdles faced in middle but atlast reached my desti. But missing up all classmates and my frdzs, as the last sem comes all tem r missing I object tis seriously.