In 1987 we used to compile projects on our Tandem "mainframes", and they would take anywhere from 20 minutes to a couple of hours (the machines were very, very slow by today's standards). The output was stored on disk in the print spooler, and rarely printed out. The spooler would hold about 2000 listings.
Periodically, the spooler would start to get full, so one of us good-hearted individuals would run a command to delete the oldest few spooler jobs.
One day, I noticed that the spooler got full, so I took on the task of deleting old jobs. I typed the wrong command, and then left for home. After about 5 minutes on the road, I realized my mistake and knew that it was deleting every spooler job. I raced back to my office, and aborted the command.
The biggest problem with the Drake Equation is that it it way too simplistic. In our galaxy, there is definitely a
habitable zone which the solar system is in. If it were much closer to the center of the galaxy, there would be too many events like energetic supernovae that would kill all life on the earth. If it were much farther away from the center, there would not be enough heavy elements to form earth-like planets.
Life is fragile and cannot tolerate too many nearby energetic events.
Life similar to Earth's probably exists elsewhere in our galaxy, but may not be very common.
I don't think the problem with sending people to Mars is the risk.
I think the problems are the cost (maybe 100x the cost) and the sheer difficulty of getting humans there alive, and making sure they can return.
With a 30% chance of getting something there successfully, there is a 9% chance of getting something there and back, and that is not considering that what you have to get there is alive.
So, it is inordinately difficult to send something alive to Mars, keep it there alive for months, and then send it back alive to the Earth. Any solution to these problems will be inordinately costly.
If it's not inordinately costly, it will have only a tiny (and I do mean tiny) probability of success.
(a) making a mountain out of a molehill about this,
(b) reporting the information 6 months late, and
(c) mangling the science in the information beyond all recognition.
This adjustment of leap seconds occurs because the second is based on the rotation of the Earth as it was in 1900. The rotation has slowed down slightly since then, so seconds have to be added once or twice a year to keep the day in sync with the sun.
This is strictly analogous to adding leap days to keep the months in sync with the seasons, because the day does not evenly divide the time of one Earth orbit. Similarly, the second no longer evenly divides one rotation of the earth.
This time difference has nothing to do with traveling through space, and is a routine matter.
Here is the actual announcement:
----------------- INTERNATIONAL EARTH ROTATION SERVICE (IERS) Paris, 1 July 2003
NO positive leap second will be introduced at the end of December 2003.
The difference between UTC and the International Atomic Time TAI is:
from 1999 January 1, 0h UTC, until further notice : UTC-TAI = -32 s
Leap seconds can be introduced in UTC at the end of the months of December or June, depending on the evolution of UT1-TAI. Bulletin C is mailed every six months, either to announce a time step in UTC, or to confirm that there will be no time step at the next possible date.
Given the failure rate of Mars probes over the last 40 years, I'm surprised anyone thinks there's a reasonable chance of sending people there within 10 years.
Spolsky feels that programmers fear design
because they consider it a creative process
rather than a logical one...
Wow!
Whoever wrote that apparently feels that creativity and logic are opposites or contradictory.
In software engineering, I see logic as the medium for creative expression of ideas. They are two different things and they happily coexist, particularly in programming and mathematics and science and any number of other fields.
Slashdot Mirror
Periodically, the spooler would start to get full, so one of us good-hearted individuals would run a command to delete the oldest few spooler jobs.
One day, I noticed that the spooler got full, so I took on the task of deleting old jobs. I typed the wrong command, and then left for home. After about 5 minutes on the road, I realized my mistake and knew that it was deleting every spooler job. I raced back to my office, and aborted the command.
Nobody even noticed.
Well, the theorists admittedly don't have any direct evidence.
There are other plausible scenarios that lead to an ice-age, not just NOx haze from nearby supernovae.
Still, the idea that a nearby supernova has actually triggered an ice-age is very intriguing.
The biggest problem with the Drake Equation is that it it way too simplistic. In our galaxy, there is definitely a habitable zone which the solar system is in. If it were much closer to the center of the galaxy, there would be too many events like energetic supernovae that would kill all life on the earth. If it were much farther away from the center, there would not be enough heavy elements to form earth-like planets.
Life is fragile and cannot tolerate too many nearby energetic events.
Life similar to Earth's probably exists elsewhere in our galaxy, but may not be very common.
I think the problems are the cost (maybe 100x the cost) and the sheer difficulty of getting humans there alive, and making sure they can return.
With a 30% chance of getting something there successfully, there is a 9% chance of getting something there and back, and that is not considering that what you have to get there is alive.
So, it is inordinately difficult to send something alive to Mars, keep it there alive for months, and then send it back alive to the Earth. Any solution to these problems will be inordinately costly.
If it's not inordinately costly, it will have only a tiny (and I do mean tiny) probability of success.
The Associated Press is
:
(a) making a mountain out of a molehill about this,
(b) reporting the information 6 months late, and
(c) mangling the science in the information beyond all recognition.
This adjustment of leap seconds occurs because the second is based on the rotation of the Earth as it was in 1900. The rotation has slowed down slightly since then, so seconds have to be added once or twice a year to keep the day in sync with the sun.
This is strictly analogous to adding leap days to keep the months in sync with the seasons, because the day does not evenly divide the time of one Earth orbit. Similarly, the second no longer evenly divides one rotation of the earth.
This time difference has nothing to do with traveling through space, and is a routine matter.
Here is the actual announcement:
-----------------
INTERNATIONAL EARTH ROTATION SERVICE (IERS)
Paris, 1 July 2003
NO positive leap second will be introduced at the end of December 2003.
The difference between UTC and the International Atomic Time TAI is
from 1999 January 1, 0h UTC, until further notice : UTC-TAI = -32 s
Leap seconds can be introduced in UTC at the end of the months of December or June, depending on the evolution of UT1-TAI. Bulletin C is mailed every six months, either to announce a time step in UTC, or to confirm that there will be no time step at the next possible date.
Given the failure rate of Mars probes over the last 40 years, I'm surprised anyone thinks there's a reasonable chance of sending people there within 10 years.
Um, they haven't picked it up. The intent was for the orbiter to pick it up, not earth-based antennas.
Recently I ordered 6 CDs from a CD club, completely unrelated to Christmas.
When they came in the mail, my wife intercepted them and wrapped them and put the box under the tree as a gift to me. She warned me it was a joke.
Imagine my surprise when I opened it and saw what it was!
Q: What's the difference between an accountant and an actuary? A: An accountant has personality.
Wow!
Whoever wrote that apparently feels that creativity and logic are opposites or contradictory.
In software engineering, I see logic as the medium for creative expression of ideas. They are two different things and they happily coexist, particularly in programming and mathematics and science and any number of other fields.