The September monthly sunspot graph

The Sun continues to show a reluctance to come out of its solar minimum. Today NOAA’s Space Weather Prediction Center published its monthly graph, showing the sun’s developing sunspot cycle in comparison with the consensis prediction made by the solar science community in May 2009. As you can see below, actual sunspot activity remains far below what was predicted by the red line.

September 7, 2010 Solar Cycle progression

As I noted when I posted the July and August graphs, the Sun’s ramp up to solar maximum continues to be far slower and weaker than predicted. After two hundred years of watching a vibrant and strong solar cycle, it appears increasingly likely that we are heading towards some quiet time on the Sun.

Natural Bridge, on the Moon

The Lunar Reconnaissance Orbiter has released another lunar cave image, this time showing a double pit entrance with a natural bridge between them. [Thanks to reader James Fincannon for the tip.]

Natural bridge

From the caption: “The bridge is approximately 7 meters wide on top and perhaps 9 meters on the bottom side, and is a 20 meter walk for an astronaut to cross from one side to the other.”

Engineering in the Columbia River Gorge

Because yesterday’s hike up Eagle Creek to Tunnel Falls (see picture below) was particularly long, 12.5 miles, I took a break from posting when I got home. Today (Monday), however, was a more easy-going day, as we did more ordinary tourist stuff, driving from place to place with only short strolls at each stop.

Tunnel Falls

The most fascinating tourist stop of the day was by far Bonneville Dam. Just as the security guard at the gate let the car in front of us through, her phone rang. When she was finished and came up to our car, she explained that we would have to wait about a half hour before going to the visitor center, as they needed to open the swing bridge so that a barge could go through the locks. At first I thought this was very unfortunate timing. In the end, it turned out to be fortuitous indeed. We parked at the viewing area above the locks and watched five barges, tied tightly together as a unit and pushed upstream by a tug, slide gently into the lock with barely inches on either side. Neither Diane or I could believe how little spare room the tugboat captain had to pilot this massive object. The gigantic downstream doors then closed (while I quipped that music from Star Wars should be playing) and the lock was quickly filled with water, raising the barges/tugboat up almost a hundred feet. The upstream doors than opened and the barge headed out. All told, the whole operation took less than 45 minutes.

The barges enter the lock

The barges with the lock filled

We then took a tour of the dam’s first power station, with its ten turbines all in a row. Unfortunately, none were operating at the moment. Nonetheless, whenever I see places like this (such as when I visited Hoover Dam back in 2005), I can’t help but be reminded of the scene from the science fiction movie Forbidden Planet, when Walter Pigeon gives us a tour of the Krell underground machine. Unlike the Krell, however, it didn’t take millions of years for us to learn how to build such breath-taking big dams and power stations. We did it less than 150 years after the discovery of electricity!

Bonneville Dam power station

The Columbia River Gorge

We’ve moved on from Mt. St. Helens to the Columbia River Gorge. Below is a shot of Vista House at Crown Point, looking east into the gorge. In the distance you can see Beacon Rock.

The Columbia River Gorge

Today’s hike was short, a six mile loop starting at Multnomah Falls (620 feet total).

Multnomah Falls

The falls and hike are probably among the most popular tourist attractions close to Portland. And since today was Saturday, there were a lot of people around. Nonetheless, the numbers quickly dropped as we worked our way up the trail, dropping to only a handful of people once we climbed past the top of the falls. The hike itself included a lot of waterfalls and babbling streams, but it also weaved its way through some impressive evergreen forests.

forest of trees

I find it sad how few people are willing to do the little extra work necessary to reach these beautiful places. At one point on our way down, we passed a family that was clearly discussing whether to continue. They had already climbed about 80 percent of the way up, but the father and mother were tired and seemed willing to stop. When the son (about 12) asked me how much farther it was to the top and I said it was only about 20 to 30 minutes, he was off like a shot, with the parents forced to follow, albeit reluctantly. My immediate thought was, “Go, kid, go!”

Living underground for months

Though this article outlines succinctly the physical and mental difficulties faced by the 33 trapped Chilean miners, it also tends to overemphasize the worst case scenerios, none of which are likely to happen. I can state from personal experience — having spent numerous weekends underground during cave exploration trips — that though their situation is very unpleasant, I have no doubt these miners will survive. Because they have contact with the surface, and therefore a regular supply of food and information, they will simply demonstrate the limitless range of human endurance, and hold on until rescue arrives.

New exoplanets

Exoplanet news! Scientists today announced the discovery of a host of planets, all orbiting a single star similar to the Sun. Though five are Neptune-sized, a sixth (not yet confirmed) might be the size of Earth. What makes this even more exciting is that the astronomers made the discovery using a ground-based telescope.

But wait, there’s more! Thursday NASA will hold a press conference about a new discovery by Kepler!

The desert below Mt. St. Helens

On May 18, 1980, Mt. St. Helens erupted, the blast throwing the north slope of the mountain out and downward in a terribly hot wave of ash, rock, and magma. All life in its path was destroyed. Forests were ripped to the ground, then buried. The force of the wave tore into Spirit Lake, pushing the water sideways so that it sent its own wave 500 feet up the side of the opposite mountain. The mountain then dumped so much material into the lake that it actually doubled in size, its shores raised 200 feet.

It is now thirty years later. After years of slowly oozing out two large lava domes into its shattered crater, Mt. St. Helens had finally quieted down enough for the National Park Service to permit hikers to once again return. Not only do trails now criss-cross the blast zone below the crater, if you make arrangements in advance you can actually hike up the mountain’s south face and look down into the crater.

Our hike yesterday at Mt. St. Helens consisted of two parts. The first took us down onto the Loowit Trail, the closest the National Park Service permits hikers to get to the volcano’s lava domes. The second part was a short hike down to the shoreline of Spirit Lake.

Two things stood out in both these hikes. First, I was astonished how much of the surrounding landscape remains devastated, barren, and desert-like, decades after the eruption. I come from the East, where you expect a barren field to quickly become overgrown with life. Yet, even in the rainy climate of the northwest the destruction left by the volcano is so profound it is going to take many more decades for the forest to reclaim its former glory.

Thus, the land between the mountain and Spirit Lake more resembles the deserts of the American southwest than the lush, wet forests of the Cascade mountains. At one point I even noted to Diane how the Loowit trail reminded me of the Tonto Plateau trail in the Grand Canyon — a wide shadeless terrain crossing periodic dry gullys.

Loowit Trail looking up at Mt. St. Helens

Still, in what had been a dead zone thirty years ago, small life has reappeared, from chipmunks to a variety of scrubs and grasses. There are even a scattering a small young evergreens, signaling the eventual return of the forest.

At Spirit Lake, farther from the volcano, the landscape showed even more life. Yet, the lake was still half covered with a mat of dead logs, left over from the blast. And the hillsides were littered with the blown-down logs. Though many have rotted away in the ensuing decades, many remain, scattered about like giant toothpicks.

logs on lake

The second thing notable was how much the barren landscape of Mt. St. Helens was dominated by the research work of scientists. Wherever we looked we saw evidence of it. Instruments and sensors could be spotted everywhere. Helicopters transporting scientists flew over repeatedly. We even met a young researcher gathering animal traps, part of the continuing census of life in the blast zone. As she explained to me, they are tracking the changing species as life re-enters and repopulates the dead zone.

researcher with samples

From a human perspective, this research is profound. Though natural disasters such as the Mt. St. Helens eruption are not unusual things in the history of our planet, humans have never had an opportunity to study the aftermath of one in such detail. The knowledge gained will be priceless beyond measure. And that we as a society are willing to dedicate the funds to do this work will speak very well of us to future generations.

ground sensor

sensor

helicopter

Harvard researcher admits to research misconduct

Another scientific scandal, this time in the field of animal and human cognitive research: Harvard scientist Marc Hauser has admitted to eight instances of misconduct. Three key quotes:

The university said in a statement last week that Dr. Hauser or a co-author had been directed to correct three published papers for which the original data could not be found. [emphasis mine]

Harvard itself had faced growing criticism for not releasing more details of the inquiry since The Boston Globe reported on Aug. 10 that the university had found evidence of scientific misconduct in Dr. Hauser’s lab. On Friday, Michael D. Smith, dean of the Harvard faculty of arts and sciences, issued a letter to the faculty confirming the inquiry and saying the eight instances of scientific misconduct involved problems of “data acquisition, data analysis, data retention, and the reporting of research methodologies and results.” No further details were given.

Harvard’s findings against him, if sustained, may cast a shadow over the broad field of scientific research that depended on the particular research technique often used in his experiments.

Gee, this sure sounds a lot like the Phil Jones/East Anglia University climategate scandal, where both the researcher and his university provided cover for each other, thereby leaving a cloud over a vast amount of climate research that depends on Jones’s data.

A cloudy day in Paradise

We were back at Mt. Rainier today, this time doing one short hike and one long one, totaling 8.6 miles. The short hike took us to the Grove of the Patriarchs, a small grove of thousand year old trees. The long hike took us up to 7200 feet elevation on the flanks of Mt. Rainier. Unfortunately, the mountain was shy today, keeping itself hidden behind clouds for most of the day. Near the top of the climb the clouds parted for about 30 seconds, and I was able to get a signal snapshot of it. Otherwise, we spent most of the hike in the mist, which was beautiful in its own way.

Grove of the Patriarchs

Mt. Rainier, in the clouds

Obama’s traffic jam

The charade in Los Angeles on Monday when President Obama arrived for a fundraiser and shut down traffic during rush hour — causing a storm of angry protest — is another very obvious illustration of the great disconnect between today’s ruling class and the general public.

It’s not just that Obama seemed oblivious to the traffic chaos he created. It is that he, as well as most politicians today (from both parties), truly expect large areas of a city to be closed down for their convenience, and don’t seem to give a damn that by doing so they make life miserable for everyone else.

To paraphrase what Glenn Reynolds likes to say, traffic jams are for “the little people.”

Obama’s actions here are far from new and have actually been deeply institutionalized since the 1960s, following Kennedy’s assassination. Originally designed to protect a president from attack, the shutting down of highways quickly became a tool to make the president’s life as easy as possible while demonstrating to all his lordly superiority.

For example, I personally experienced this kingly arrogance back in 1979. I needed to get from my house in Astoria, Queens, to LaGuardia Airport, normally a very short 10 minute drive. But as I pulled into the ramp for the Brooklyn-Queens Expressway I found myself being waved to a stop by a policeman. The expressway was being closed so that President Jimmy Carter could use it. I, along with hundreds of others, was forced to sit there for thirty minutes, waiting for his entourage of approximately thirty limousines finally go by. To say that this infuriated me is to put it mildly.

Nor do I think this behavior is reserved to Democrats. I am sure that my readers could easily cite similar events during past Republican administrations.

Nor is it limited to American political leaders. The ruling class of the defunct Soviet Union made it offical policy. There, those in power built many urban roadways with special lanes reserved exclusively for communist party officials. Moreover, when they used those lanes the street lights could be commandeered, turning them all green so that anyone on a cross street had to wait.

In the U.S. we have not yet come that far. Yet, that presidents feel it their right to shut down entire transportation systems for their mere convenience suggests that sadly we don’t have that far to travel.

Unless of course the public, which still has the vote, does something about it.

A day spent in Paradise

Diane and I spent today hiking the shorter trails near the visitor center at Mt. Rainier, in an area called Paradise. Below are two pictures to give you a feel. Tomorrow we start on some longer hikes, getting higher on the mountain. Later in the week we head to Mt. St. Helens.

Diane at the start of the trail

Alpine flowers

Old Media, Old News

The New York Times today published an op-ed outlining the serious dangers we face should the Sun unleash a solar flare or coronal mass ejection of sufficient power to knock out our electrical grids. After describing the horrors of Hurricane Katrina, the author then says

We are similarly unready for another potential natural disaster: solar storms, bursts of gas on the sun’s surface that release tremendous energy pulses.

Now this might be interesting, had it been published in 1988. At that time, the electrical grids used in the U.S. and Canada were very much unprepared for a sudden solar storm. Moreover, the Sun at that time was ramping up towards a particularly active solar maximum. The result: On March 13, 1989, the power grid that supplied electricity to Quebec and 200 utility companies in the U.S. came crashing down, overloaded by a power surge caused by a burst of energy sent hurtling towards the Earth, by the Sun.

However, to report this threat today as if it was news is somewhat laughable. Since the 1990 solar maximum, the world’s electrical systems have been very much aware of the problem and have instituted numerous safeguards should the Sun burp at them again. It was for this reason that there were few problems during the next solar maximum in 2001, even though it was almost as powerful as the maximum in 1990.

The real news story concerning the Sun is how inactive it has been, for reasons scientists do not understand. Not only was the recently concluded solar minimum the longest and deepest in almost a hundred years, the subsequent solar activity leading to the next solar maximum has been far weaker than every prediction. At the moment, the Sun appears headed for the weakest solar maximum in two hundred years. And when that last happened, the Earth experienced a period of significantly cold weather, also for reasons that scientist do not yet understand.

It is this story that journalists should be covering.

the solar cycle

More questions raised about Mann’s hockey stick graph

A new research paper, written by statistical scientists and to be published next month in the Annals of Applied Statistics, has found that Michael Mann’s hockey stick graph, showing a steep increase in global temperature in the last two hundred years, is statistically invalid. Key quote:

Research on multi-proxy temperature reconstructions of the earth’s temperature is now entering its second decade. While the literature is large, there has been very little collaboration with university level, professional statisticians (Wegman et al., 2006; Wegman, 2006). Our paper is an effort to apply some modern statistical methods to these problems. While our results agree with the climate scientists findings in some respects, our methods of estimating model uncertainty and accuracy are in sharp disagreement.

[We] conclude unequivocally that the evidence for a ”long-handled” hockey stick (where the shaft of the hockey stick extends to the year 1000 AD) is lacking in the data. The fundamental problem is that there is a limited amount of proxy data which dates back to 1000 AD; what is available is weakly predictive of global annual temperature. Our backcasting methods, which track quite closely the methods applied most recently in Mann (2008) to the same data, are unable to catch the sharp run up in temperatures recorded in the 1990s, even in-sample. [emphasis mine]

In other words, the temperature data going back to 1000 AD is poor, and cannot be reliably used to prove a sudden increase in global temperature in the last two hundred years. More importantly, according to this paper, Michael Mann tried to use statistics to prove his point, without consulting any statisticians.

Sloppy journalism from the BBC

Though solar scientists have discovered that certain recent solar behavior might help explain the long and deep solar minimum that just ended, this BBC article immediately tries to give that result credit for explaining everything. To quote:

Solar physicists may have discovered why the Sun recently experienced a prolonged period of weak activity.

NOT! The result only observed a change in solar behavior beneath the surface, whereby the meridional flow slowed down as well as lengthened significantly into the high latitudes, and that this change occurred at the same time as the weak solar minimum. The paper made no attempt to explain why this happened, nor did it provide a theoretical explanation for how these changes resulted in a weak solar minimum.

Finally, and far more important, scientists still have no good theory for explaining the solar cycle in the first place. “We think it’s the solar dynamo [that causes the solar cycle],” noted Dean Pesnell of the Goddard Space Flight Center when I interviewed him for my Sky & Telescope article, What’s Wrong with Our Sun? (August 2009). “But we don’t undertand how the dynamo works, as yet.”

The BBC should be more careful in how it reports a story like this.

Astronomers announce their recommendations for the next decade

After two years of discussion among hundreds of astronomers, the committee for the 2010 Decadal Surveyn for Astronomy and Astrophysics announced its recommendations today. The two main recommendations were

The report also called for the federal government to become a partner in one of the two giant ground-based optical telescopes now in the planning stages. In addition, the report recommended that the government increase its participation in the Laser Interferometer Space Antenna (LISA), a space telescope designed to detect gravity waves, as well as commit monies to begin the design work for a new high resolution X-ray space telescope. Other recommendations including asking NASA to increase its support for medium-sized space telescopes.

The report did not recommend any replacement for the Hubble Space Telescope.

This report follows earlier decadal surveys, for the 1970s, 1980s, 1990s, and 2000s, all of which had enormous influence on what federal agencies and astronomers built over the following decade. For example, these decadal surveys recommended the construction of the VLA, the Chandra X-Ray Observatory, the Spitzer Space Telescope, and a host of other telescopes, all of which were built.

Reporter arrested for discussing politics

Freedom of speech alert. In this post, I noted that though it seemed as if the arrest of four protesters on the University of Texas campus during a visit by President Obama seemed a violation of their rights, there wasn’t enough information in the reports to know for sure. We now have more information. Read this report also. And watch this video of the arrest of one protester, while wearing a press badge, and tell me if this isn’t an abuse of power.

Rebuilding the American space program — the right way

In reading my post, Both for and against the Obama plan, reader Trent Waddington emailed me to say that this “is so fatalistic that it seems you don’t think it is worthwhile even spending a few minutes explaining why the policy is good. It’s easy to dismiss something a politician says as the stopped clock that is right twice a day. It’s harder to set aside your skepticism and explain why something is good policy.”

Trent is absolutely correct. What I wrote was very depressing and fatalistic. However, I think it very important to be coldly honest about things, no matter how bad they look. Once you’ve done that, you then have the right information necessary for fixing the situation.

My problem with most of the debate about the future space policy of the United States, — as well as innumerable other modern issues faced by our government — is that people don’t seem to want to face up to the reality of the problem. In the case of space and Obama, I doubt any advice, gentle or otherwise, is going to move him into putting forth a plan for NASA that has any realistic chance of getting passed by Congress. As I noted in a different post, he doesn’t play the game. He acts like the worst sort of autocrat, convinced that if he simply says what he wants to do, everyone must agree.

The reason the good part of his plan (commercial space) is not passing Congress is not because people think it is a bad idea. It is being rejected because » Read more

Mapping daylight at the Moon’s South Pole

Using data from the Japanese lunar orbiter Kaguya, scientists have identified several locations near the Moon’s south pole that are in daylight from 86 to 94 percent of the time. Key quote from abstract:

The place receiving the most illumination (86% of the year) is located close to the rim of Shackleton crater at 88.74°S 124.5°E. However two other areas, less than 10 km apart from each other, are collectively lit for 94% of the year. We found that sites exist near the south pole that are continuously lit for several months during summer. We were also able to map the locations and durations of eclipse periods for these areas. Finally we analyzed the seasonal variations in lighting conditions, from summer to winter, for key areas near the south pole. We conclude that areas exist near the south pole that have illumination conditions that make them ideal candidates as future outpost sites. [emphasis mine]

Below is a composite close-up image of the rim of Shackleten crator that I assembled using this Lunar Reconnaissance image. The key quote from the full caption :

The full [Narrow Angle Camera] mosaic reveals a shelf on the southeast flank of the crater that is more than two kilometers across and perfectly suitable for a future landing. The extreme Sun angle gives the surface an exaggerated rough appearance, but if you look closely at this scale any area that is between the small craters might make a good landing site.

Rim of Shackleton Crater

Melting Ice on Mars?

These Mars Reconnaissance Orbiter images show in increasing magnification a puzzling feature in the southeast part of a ice mound in Louth Crater on Mars. Located at 70 degrees north latitude, this is the farthest south that scientists have found permanent water ice. The close-up image suggests melting ice with the draining water running down hill to the south, though on Mars the low air pressure would cause any liquid water to evaporate instantly. Key quote:

These may be the crests of partially defrosted dark sand dunes or perhaps some other feature that we do not understand. This is the only area on Louth where these enigmatic ridges are found.

wide view of crator mound

Middle view of ice mound

Closeup of ice mound

The great disconnect

The recent history of NASA illustrates a fundamental problem with how our political class thinks.

In 2004 George Bush announced that NASA would have a new goal, that of the exploration of the solar system. The shuttle would complete construction of the International Space Station and then be retired in 2010. NASA would meanwhile build a replacement for the shuttle, designed to return to the Moon and beyond, and have it flying by 2014.

Notice the gap? The shuttle retires in 2010, four years before its replacement is available. Notice also that the plan insisted that ISS would be finished, fully occupied, and in need of significant resupply and maintenance during this entire time, when neither the shuttle or its replacement would be on hand.

Yet, as obvious as this seems, no one at NASA, in the Bush administration, or in Congress, seemed to notice this gap. The Bush plan was implemented exactly as described, so that today we are about to be left with a space station in orbit and no way to reach it for at least four years. (That other countries can reach the station changes nothing: the United States has been left hanging, lacking a method for transporting its crews to its own space station.)

It was as if, among the political and elite class that runs the government, there was great disconnect between the fantasy of the intended plan and the reality of its implementation. » Read more

A ground-based telescope matches the Hubble Space Telescope-NOT

Correction.Regular reader James Fincannon emailed me to say that he thinks the image below is an artist’s impression. He is correct. I should have looked more closely at the press release. In reading the actual research paper [pdf] on the results it seems that the VLT did some very sophisticated spectroscopy, thereby measuring the uneven distribution of the velocity and density of the gas around the star. The image below was then created, based largely on Hubble images combined with the new data. In other words, this ground-based telescope did not match the abilities of a space-based telescope in any way. Had the Hubble images not existed the astronomers would have struggled to interpret their spectroscopic data.

Some important astronomy news: The European Southern Observatory’s Very Large Telescope (VLT) has released this spectacular image of supernova 1987a, the first and so far only supernova visible to the naked eye since the invention of the telescope.

SN1987a

This image is important for two reasons. First, The data shows that the supernova explosion was not symmetrical, with more material being thrown outward in some directions than in others. This fact confirms what astronomers in recent years have increasingly come to believe: Supernovae explosions are not simple spherical bursts, but chaotic events ripping stars apart in a lopsided manner.

Second, this image demonstrates that ground-based telescopes are becoming amazingly good at doing what the Hubble Space Telescope has done routinely for the past two decades. Five years ago, no telescope on the ground could have resolved the inner ring of supernova 1987a. Only Hubble in space had that capability. Now, VLT can do it, almost as well as Hubble. Though a space-based telescope can still beat any ground-based telescope, it is great news that the technology for ground-based telescopes has improved so much, especially since there presently are no plans to replace Hubble.

The August monthly sunspot graph

Waking up is hard to do. Today NOAA’s Space Weather Prediction Center once again published its monthly graph, showing the progress of the sun’s sunspot cycle in comparison with the consensis prediction made by the solar science community in May 2009.

August 3, 2010 Solar Cycle progression

As I noted when I posted the July graph, the data continues to show that the Sun’s ramp up to solar maximum is far slower and weaker than predicted, despite the stories this week about how Sunday’s coronal mass ejection demonstrates that the sun is “waking up.”

Lost British ship found in Arctic after almost 150 years

Using sonar equipment Canadian archeologists have detected the underwater remains of the British ship Investigator, abandoned in the Canadian archipelago of islands by Captain Robert McClure and his crew in 1853. McClure had been sent out to both find the Northwest Passage as well as locate the missing Franklin expedition. As winter had set in in September 1851, however, McClure had anchored the ship for refuge in a bay he named Mercy Bay on the coast of Banks Island. As Pierre Berton noted in his wonderful history of the exploration of the Arctic in the 1800s, The Arctic Grail, Mercy Bay was not a refuge but “a cul-de-sac in which the crew would be confined for the next two years and from which the ship itself would never be freed.” Now, that ship has been rediscovered after almost 150 years.

Picture of the day from Mars

Sand dunes on Mars, from the HiRise camera on Mars Reconnaissance Orbiter:

Dunes on Mars

Fun quote:

These dunes are “barchan” dunes, which are also commonly found on Earth. Barchan dunes are generally crescent-shaped, with their “horns” oriented in the downwind direction. They have a steep slip face (the downwind side of the dune). Barchan dunes form by winds that blow mostly in one direction and thus are good indicators of the dominant wind direction. In this case, the strongest winds blow approximately north to south.

The failure of the past and a hint of the future

The coolant system failure on the International Space Station this weekend and the upcoming spacewalks being planned to fix it is a dramatic and fascinating story, capturing the interest of the general public while causing some news pundits to express fear and dread about science fiction scenerios of disasters in space.

The situation is hardly that death-defying. The station’s cooling systems have a lot of redundancy, all of which are being used to good effect. Moreover, the spacewalk repair to install a replacement pump module, though challenging, is exactly the kind of thing the astronauts have been trained to do. I expect them to do it with few problems. I would be far more surprised if they have serious difficulties and fail to get it done.

What this failure foreshadows, however, is the future on ISS. As the years pass and systems age, » Read more

Poor leadership by Obama on NASA

Glenn Reynolds of Instapundit today said the following (in recognizing Jeff Foust’s op-ed for Technology Review):

CONGRESS BLOWS IT: Commercial Spaceflight, We Have A Problem. Congress will always choose short-term pork over long-term development unless there’s strong Presidential leadership. But while the Obama space policy is good, the White House hasn’t provided the kind of legislative push it takes to make it work. Without strong leadership, a good policy will always lose out to pork.

Didn’t someone say this already? In fact, didn’t that someone say this more than once?

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