Unfortunately due to some technical difficulties I couldn’t group my data with the rest of my group’s so here’s the data I was able to collect. We will try to combine the posts soon. Sorry for the inconvenience!

Manufacturing of Solar Cells and Necessary Components:

Şen (2008) writes that of all the renewable energy sources available to us, the sun gives the most energy on a consistent basis even with reductive atmospheric factors like absorption and molecular scattering. He also notes that the wavelengths in sunlight are primarily in the form of visual light which are exactly what most solar cells need to operate.  

Lynn (2010) goes into detail about the different forms of solar cells including…

    • Silicon Cells (Monocrystalline, Polycrystalline, and Amorphous) – considers this one the quintessential solar cell due to its low cost and good efficiency

    • CIGS and CdTe cells

    • Multijunction cells

    • Organic Cells

The only components of solar cells specifically known to cause environmental damage are lead, from the lead acid batteries (PTIG 1985) and cadmium residue from the CdTe cells. Despite the possible environmental effects these are not the most commonly used solar cells if properly disposed these solar cells could become a great way to use the cadmium byproduct common in zinc mining safely (Fthnakius 2003).   

Rough Cost of Solar Cells:

Lynn (2010) notes that the cost of a solar cell during 1970 was around $300 per Watt

Currently online solar energy calculators average a cost of about $7.00 per Watt for a common monocrystalline silicon solar cell including parts and instillation. (Cooler Planet)

Efficiency of silicon based solar panels, and other, newer varieties of photovoltaic cells:

The NREL (National Renewable Energy Laboratory) put together a graph detailing the lab efficiencies of multiple types of solar cells over a time frame from 1975 to 2010. The graph shows that multijunction cells have the highest efficiency of around 38% but that all forms of solar cells have been getting progressively more efficient.

 http://www.nrel.gov/pv/thin_film/docs/kaz_best_research_cells.ppt   

Lynn (2010) notes the most common type of solar cell, silicon cells range from 11%-16% efficient out in the field.

Potential Issues in cost and efficiency:

Based on a solar energy calculator (Cooler Planet) for Vassar to switch over 50% of the dorm’s electricity to solar energy it would cost nearly 2.5 million dollars even after tax incentives (Dorm electricity estimate based on (Small 2008)). This estimate fluctuates between 2 million and 3.5 million depending on the electric provider however and is based on the average solar radiation value for Dutchess County. It would take Vassar 15-20 years for the monetary savings of the solar cell to break even. 

Lynn (2010) argues that although the upfront fees are high for converting, the long life span of solar cells of around 20 to 25 years along low maintenance fees make it a much safer option than most other energy sources. He also mentions the energy payback times for this area of the United States would be about 4 years. He refrains from any mention of cost during this section however.     

Physics of photovoltaics: how it converts sunlight to energy:

Knier’s article (2002) is a qualitative introduction to the underlying physics and processes of photovoltaics. He has a basic explanation of the photoelectric effect and the general assembly of a single silicon cell solar panel. It also has a short history of the science of photovoltaics noting its origins and its popularity as a power source for satellites.

Nelson (2008) however presents similar information in a more quantitative form, focusing on derivations which explain the factors that affect the semiconductors used for solar cells and the P-N junction of the solar cells. The calculations remain general however and are not used to come to any particular conclusions. Other calculations include one on general efficiency.

Lynn (2010) notes that other factors like the weather of a particular area and spectral distribution of the sunlight hitting the panel play a significant role. His analysis of the physics remains primarily focused on a qualitative analysis of the different roles and forms solar cells can take to supply a wide variety of power on a global level.  

Future of photovoltaic technology:

Where Lynn (2010) believes the future of solar cells will be determined by the advancement of silicon cells Nelson (2003) argues it is the multijunction cells which will be focused on

Current advancement include solar cells that can rebuild themselves (BBC 2010) and silicon cells reaching even higher efficiencies of around 24% in the lab (Science Daily 2008)

Further ideas for solar cell improvement include sattlelites with solar panels beaming the energy to earth in the form of microwaves, desert spanning solar farms and solar beam collectors to focus sun rays right at the solar cells (Şen 2008)

Sources

“BBC News – Tiny Solar Cells Fix Themselves.” BBC – Homepage. 5 Sept. 2010. Web. 20 Apr. 2011. http://www.bbc.co.uk/news/technology-11181753.

Fthenakis, Vasilis M. “Life Cycle Impact Analysis of Cadmium in CdTe PV Production.” Renewable and Sustainable Energy Reviews 8.4 (2004): 303-34. Scopus. Web. 20 Apr. 2011. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VMY-4BF004T-1&_user=557743&_coverDate=08%2F31%2F2004&_alid=1725917696&_rdoc=3&_fmt=high&_orig=search&_origin=search&_zone=rslt_list_item&_cdi=6163&_docanchor=&view=c&_ct=973&_acct=C000028458&_version=1&_urlVersion=0&_userid=557743&md5=48d4721ebf6210cbf9b046c23c45c54d&searchtype=a#toc24

“Highest Silicon Solar Cell Efficiency Ever Reached.” Science Daily: News & Articles in Science, Health, Environment & Technology. 24 Oct. 2008. Web. 20 Apr. 2011. http://www.sciencedaily.com/releases/2008/10/081023100536.htm.

Knier, Gil. “How Do Photovoltaics Work?” NASA Science. 2002. Web. 17 Apr. 2011. http://science.nasa.gov/science-news/science-at-nasa/2002/solarcells/.

Kazmerski, Lawrence. “Best Research Cell Efficiencies.” National Renewal Energy Laboratory, 10 Sept. 2010. Web. 19 Apr. 2011. http://www.nrel.gov/pv/thin_film/docs/kaz_best_research_cells.ppt.

Lynn, Paul A. Electricity from Sunlight: an Introduction to Photovoltaics. Chichester: Wiley, 2010. Print.

Nelson, Jenny. “Chapter 1 and Chapter 10.” The Physics of Solar Cells. London: Imperial College, 2003. 1-16+. Print.

Şe̜n, Zekai. Solar Energy Fundamentals and Modeling Techniques: Atmosphere, Environment, Climate Change and Renewable Energy. London [u.a.: Springer, 2008. Print.

Small, Jesse. “Since 1866: Sustainability Committee Sparks Energy Challenge.” Ed. Hayley Tsukayama. The Miscellany News. 10 Apr. 2008. Web. 20 Apr. 2011. http://misc.vassar.edu/archives/2008/04/sustainability_3.html.

“Solar Calculator.” Cooler Planet. Web. 20 Apr. 2011. <http://solar.coolerplanet.com/Articles/solar-calculator.aspx>.

Powered Armor: The Future of Warfare? An Outline

After an hour of failed attempts, I was not able to transfer the outline successfully from MS Word to the post editor, so I’m putting this PDF up as an alternative.

Please see attached.

History of holography:

• Developed by Denis Gabor in article, “microscopy by reconstructed wavefronts (Gabor, 1949)
• First practical usage of holography done by Yuri Denisyuk and Emmett Leith at University of Michigan in 1962

Holography Mechanics:

• Technique that allows electromagnetic waves from an object to be recorded on a recoding device and later reconstructed by another electromagnetic wave source such that an image of the object can be seen by an imaging system.
• Image produced by the hologram is such that it changes as the position and orientation of the viewing system changes making it seem 3D.
• Recording media – dichromate gelatin, photoresists, photothermoplastics

How to create a hologram:

• Illumination beam from the object of set of objects falls on the recording medium.
• Another light beam known as the reference beam also illuminates the recording medium so that there is interference between both beams (shown below).

image via Wikipedia.org

• Generates a pattern of varying intensity, which is recorded on the recording medium and is reconstructed later by another light beam (shown below).

image via Wikipedia.org

A more detailed explanation of how holograms are made is shown in the video below:

Developing Holographic Data Storage:

• Massive amounts of data are stored in the form of holographic images on a relatively small area using lasers.
• Holographic data storage captures data using an optical interference pattern described above within a thick, photosensitive optical medium. Light from a laser beam is divided into dark and light pixels, which are used to create two separate optical patterms in the medium. By adjusting the reference beam angle, wavelength and media position, multiple holograms can be stored on a single volume. The process is shown in the diagram below:

via www.inphase-technologies.com

• Azobenzene-containing polymers have been investigated as a medium for holographic discs. When irradiated with linearly polarized light, azobenzene molecules change their orientation to align perpendicular to the light,  a property known as macroscopic optical anisotropy. This photo induced change can be used to write information into the material, either bit by bit or by holography. But the recording laser light cannot penetrate right through thick azobenzene films because azobenzene units absorb strongly at this wavelength. Therefore, most studies have been limited to recording in films only a few micrometers thick.
• Scientists have investigated diluting the azobenzene molecules in a polymeric matrix that is transparent at the recording wavelength. The recording light can penetrate through the samples, which can be several hundreds of micrometers thick. but the reduced azobenzene content can result in a decrease in the sensitivity and stability of the recorded holograms. Different approaches based on random copolymers, block copolymers and blends of polymers are being examined to try to fulfill application requirements.

The Technology and Applications of Holographic Data Storage:

• The most obvious application for holographic data storage comes from storing any kind of data on storage media for consumer and business purposes.
• Holographic media can store huge amounts of data because information is encoded in layers throughout the entire disk, not just on a single reflective surface as in today’s optical media.
• How data is read off of a holographic disk: The medium may be a rotating disk containing a polymeric material, or an optically sensitive single crystal. The key to making the holographic data storage system work is the second laser beam which is fired at the crystal to retrieve a page of data. It must match the original reference beam angle exactly. A difference of just a thousandth of a millimeter will result in failure to retrieve the data.
• GE said that micro-holographic players will be backward read-compatible with existing CDs, DVDs and Blu-ray discs.
• Can also be utilized on business servers.
• Can be used to store any form of data.
• Nintendo is planning to use holographic storage for future products.
• If commercialized, will surpass tape and optical storage units in terms of storage size and transfer speed.
• Can store much more information than conventional optical storage devices. Early prototype holographic discs held about 300 GBs, more than 400 times the storage capacity of a CD-ROM.
• Holography promises incredibly high transfer rates–up to 1 Gb per second, 40 times faster than DVD. A holographic system can store up to 60,000 bits in a pulse of light, while a DVD can only transfer one bit of data per light pulse.
• Holographic storage has improved durability over magnetic devices such as tape drives.
• The detector, which is the imaging system for viewing holographic data, is capable of reading data in parallel since multiple holograms can be reconstructed at the same time. It has an incredibly fast data transfer rate: up to 23 MB/s for writing and 13 MB/s for reading.
• Institutes the WORM (write once, read many) data storage model, This means data cannot be overwritten and it can be stored for long periods of time without getting damaged.
• The size of the storage disk will be incredibly small because multiple images can be stored on the same disk. A prototype of a holographic data disk is shown below:

via InPhase company website

SOURCES:

http://www.computerweekly.com/Articles/2007/08/06/226027/Is-holography-the-future-for-storage.htm

http://www.economist.com/node/1956881?story_id=1956881

http://www.shacknews.com/article/53945/nintendo-exploring-holographic-data-storage

Robinson, T. (2005, June). The race for space. netWorker. 9,2. Retrieved April 28, 2008 from ACM Digital Library.

http://www.inphase-technologies.com/downloads/pdf/technology/HighSpeedHDS500Gbin2.pdf

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TVF-42RDRS7-D&_user=557743&_coverDate=04%2F01%2F2001&_alid=1725793398&_rdoc=6&_fmt=high&_orig=search&_origin=search&_zone=rslt_list_item&_cdi=5533&_sort=r&_st=13&_docanchor=&view=c&_ct=11830&_acct=C000028458&_version=1&_urlVersion=0&_userid=557743&md5=2e1b8a216746ae188e9e3bd44dea3d6a&searchtype=a

http://digitalcommons.providence.edu/cgi/viewcontent.cgi?article=1017&context=facstaff_pubs&sei-redir=1#search=%22applications+of+holographic+data+storage%22

http://sites.google.com/site/fictiontoreality/holographic-data-storage-will-save-internet

Project 16 (Angel, Nico and Nick) Data!

Manufacturing of Solar Cells and Necessary Components:

The manufacturing process can be broken down into the following steps (click the link above below for further details):

1. Purifying the silicon
2. Making single-crystal silicon
3. Making silicon wafers
4. “doping” – adding of impurities: phosphorous gas burrows into nearly melted silicon
5. placing electrical contacts – connect to the receiver of the produced current
6. the anti-reflective coating
7. encapsulating the cell

http://www.madehow.com/Volume-1/Solar-Cell.html

See also youtube video from the discovery channel that could be incorporated into the PowerPoint:

http://www.youtube.com/watch?v=qYeynLy6pj8

Rough Cost of Solar Cells:

Efficiency of silicon based solar panels, and other, newer varieties of photovoltaic cells:

-Colarado State University has a large solar power generator that helps to power the university. Their field of solar panels in terms of efficiency can be viewed here: http://www.fm.colostate.edu/sustain/index.cfm?page=projects/energy

Basic results of their efficiency include the following:

• Project Surface Area: 30 Acres
• Solar Plant Capacity: 5,300 kWdc
• Date of Completion: December 2010
• Annual Energy Output: 8,500,000 kWh
• Number of Solar Panels: 23,049
• Number of Watts per Panel: 230 W
• Number of Inverters: 10

Generates equivalent electricity to power 949 homes

The following link also contains tables for different efficiencies for different varieties of solar panels (note high efficiency in cells that are not yet able to be mass produced):

http://onlinelibrary.wiley.com/doi/10.1002/pip.1021/full

Potential Issues in cost and efficiency:

-Ronna Kelly, director of UC Energy Institute argues that solar panels do not pay for themselves, and in fact constitute a poor investment choice: “the cost for an installation ranges from nearly $86,000 to $91,000, while the value of the power produced ranges from $19,000 to $51,000.”

-Currently this is a high estimate for installation, but even liberal estimates believe it would take over a decade to recapture the initial investment. (SOURCE: NICO).

The science seems to overwhelmingly support that even with the contemporary (relatively inefficient) rates of converting photons into electricity will ultimately lead to the: “reduction of the emissions of the greenhouse gases (mainlyCO2, NOx) and prevention of toxic gas emissions(SO2, particulates)” – according to Tsoutsos et al (2005).

-Include table citing reduced levels of carbon emissions on page 290.

Citation for more data:

Environmental impacts from the solar energy technologies

Tsoutsos,Theocharis; Frantzeskaki,Niki; Gekas,Vassilis

Energy Policy, 2005, 33, 3, 289-296

Physics of photovoltaics: how it converts sunlight to energy:

Political implications of solar panels – can they help us reduce our dependence on foreign fossil fuels?

The Department of Energy writes that they plan to make solar energy products cost-competitive by 2020. However, this will be of little to no use. Even if they do become cost-competitive people will still be leary of them and the fact is that solar products are not much less dangerous than energy sources now.  One problem with receiving the benefits offered by the federal government is that regulations are done on a state level rather than federal. If the state does not approve certain aspects, then any federal benefits remain void.

http://www.cleansolarliving.com/webpage.php?page=24

http://www1.eere.energy.gov/solar/

Future of photovoltaic technology:

Diaz, Alonzo, et al. (2002) write that in certain laboratory, experimental settings, extremely high concentration photovoltaic cells have achieved efficiencies of up to

A company in California called Nanosolar (2007) has recently been mass-producing a thin film capable of producing high levels of energy from sunlight at a competitive cost of one dollar per watt. Compared to usual solar cells that require glass, aluminum, copper and silicon, these cells are a thin film consisting of five layers:

1. Aluminum foil for stability.

2. Molybdenum Electrode

3. CIGS absorber / semi-conductor- an ink made of a mix of copper, indium, gallium, and selenium.

4. as in the old solar model a P/N junction, a semi-conductor that doesn’t absorb light.

5. Lastly, a clear zinc oxide semi-conductor.

Check the animation!

http://www.popsci.com/popsci/flat/bown/2007/green/item_59.html

Outline

I. How does advanced imaging technology (AIT) work?

1. Instead of relying on absorption of x-rays, backscatter systems view images through the scattering of x-ray photons
   • Elements with fewer protons tend to scatter x-ray protons, while elements with more protons tend to absorb x-ray protons
2. Characteristics:
   • Narrow, low-intensity x-ray beam
   • 2d images are simultaneously taken of a person’s front and back
   • Images allow more detailed identification of organic material

II. How effective is AIT?

1. Backscatter patterns are generally effective
   • A backscatter system has the potential to create an extremely detailed image of a person’s body, regardless of how much clothing they are wearing
2. A backscatter scanner would likely miss a weapon or explosive store in a bodily cavity

III. Even with the stigmatic concept of radiation, are there actual negative health effects that AIT scanners cause in humans?

1. People, politicians and scientists were less concerned about radiation exposure before World War II
   • Political opposition developed post-World War II due to pressures from scientific community
   • Fruit fly studies showed mutation in cells due to x-ray exposure
   • International Commission on Radiological Protection implemented a no-acceptance on radiation
2. Safe levels of radiatioon in humans
   • Single whole-body dose of 15 rem of radiation is safe
   • 70 rem of radiation per year is safe
   • These numbers are sensitive to cancer-prone individuals
3. Backscatter radiation levels
   • 5  microrem of low energy radiation exposure
   • Radiation levels are 3 millions times lower than the safe dose of 15 rem
4. Backscatter radiation put into perspective
   • Cosmic radiation on a one-way flight from Frankfurt to New York exposes passengers to a dose of about 35 Sv of radiation, whereas the dose of a backscatter scan is about .1 Sv
   • Backscatter produces radiation exposure equivalent to two minutes flying on an airplane
   • In 42 minutes of living, a person is exposed to more radiation from natural sources than used in AIT x-ray security systems
   • Various organizations have approved of backscatter usage, including the Food and Drug Administration, the Center for Devices and Radiological Health, National Institute for Standards and Technology, John’s Hopkins University Applied Physics Laboratory and, of course, the Transportation Security Administration

IV. What personal concerns are raised by AIT?

1. Health concerns
   • AIT screening is safe for everyone including children, pregnant women, the elderly and people with medical implants

1. Privacy concerns
   • Highly detailed scans produce “nude” images of passengers
     • Images are at times saved by federal agencies
       • Saved images have been leaked to the public before, notably by the technology blog Gizmodo
     • The use of scanners in airports may breach child pornography laws
   • Images produced by the scanner can be modified to be less revealing
     • Passengers’ gentials, buttocks and breasts could be blurred in the image produced by the scanner
     • Modifying the image decreases the scanner’s effectiveness at detecting explosives and other weapons

Bibliography

• “Airport full body scanners and pregnancy.” Royal College of Obstetricians and Gynaecologists. 2011. <http://www.rcog.org.uk/womens-health/clinical-guidance/airport-full-body-scanners-and-pregnancy-query-bank>.

• Cavoukian, Ann. “Whole Body Imaging in Airport Scanners: Activate Privacy Filters to Achieve Security and Privacy.” Office of the Information and Privacy Commissioner. 12 March 2009. <www.ontla.on.ca>.

• Hamilton, Jon. “New Airport Body Scans Don’t Detect All Weapons.” NPR. 14 January, 2010. <http://www.npr.org/templates/story/story.php?storyId=122499686>.

• Hupe, Oliver. “Security scanners for personnel and vehicle control: quantities and dose values.” European Journal of Radiology 63.2 (2007): 237-241.

• Johnson, Joel. “One Hundred Naked Citizens: One Hundred Leaked Body Scans.” Gizmodo 16 November, 2010. <http://gizmodo.com/#!5690749/these-are-the-first-100-leaked-body-scans>.

• Kiltou, Demetrius. “Backscatter body scanners—A strip search by other means.” Computer Law & Security Report 24.4 (2008): 316-325.

• Lord, Steve. “Aviation Security: TSA is Increasing Procurement and Deployment of the Advanced Imaging Technology, but Challenges to This Effort and Other Areas of Aviation Security Remain.” United States Government Accountability Office. 17 March 2010. <http://www.gao.gov/products/GAO-10-484T>.

• McCullagh, Declan. “Feds admit storing checkpoint body scan images.” CNET 4 August 2010. <http://news.cnet.com/8301-31921_3-20012583-281.html>.

• Transportation Security Administration. 2011. <http://www.tsa.gov/>.
• Travis, Alan. “New scanners break child porn laws.” The Guardian. 4 January 2010. <http://www.guardian.co.uk/politics/2010/jan/04/new-scanners-child-porn-laws>.

• U.S. Food and Drug Administration. 2011. <http://www.fda.gov/>.

Laser Weapons:

• Class 1 Impossibility.  They are impossible today but do not violate known laws of physics, so they might become possible someday.
• Provide discussion of laser weapon feasibility.   Cannot currently exist because we lack an appropriate portable power source and a stable lasing material.   Ray guns are possible, but must be connected to a power supply via cable.  Advances in nanotechnology provide some hope that laser weapons will become possible in the future by creating tiny power packs capable of delivering massive amounts of power.  (Physics of the Impossible, p. 41)

Parallel Worlds:

• Explore Hugh Everett’s “many worlds” idea, proposed in 1957.  Everett suggested that in an experiment like the one involving Schrodinger’s cat, the wave function does not collapse when someone looks inside the box.  Instead, since both outcomes are equally likely, the entire Universe splits, or branches.  In one branch of reality, the scientist observes a dead cat and in another branch, a living cat.  As Gribbin explains, “it isn’t so much that the Universe, or the observer, splits, but that the overall wave function, the superposition of states, has built in to itself a bifurcation at the moment in time where the measurement, or observation, is made.” (In Search of the Multiverse, p. 26).   In short, “any universe that can exist, does” (Physics of the Impossible, p. 244).
• Explain theory of “decoherence” – wherein all parallel universes are possible, but our wave function does not vibrate in unison with them anymore.
• Possibility of jumping between parallel worlds is more complex:

1. Probability of this occurring decreases with each atom in your body.  Since you possess trillions of these, you are much less likely to connect to another universe.  Explore this. (Physics of the Impossible, p. 248).
2. Gribbin, on the other hand, claims that “communication between the different branches of Everett’s Multi-verse…would be impossible, according to the same equations that describe the existence of such multiple realities…Except for one intriguing possibility…time travel.” (In Search of the Multiverse, p. 28).

• Because of Gribbin’s point here, I (Tory) will also now undertake a discussion of time travel as possible in itself and also for the purpose of jumping between parallel worlds.

Time Travel:

• Class 2 Impossibility.  Hovers near the edge of our current knowledge of physics.  Might be possible, but only millions of years in the future.
• Consistent with known laws of universe.  No matter how hard physicists try, they cannot seem to come up with any reason why it could not work.  (Physics of the Impossible, p. 242)
• Include discussion of possible methods for time travel such as wormholes.
• Also discuss paradoxes and ways of resolving them, which must include a discussion of parallel worlds/many worlds and “branches” of time.

Black Holes

For the purposes of this project, we will focus on Scharzschild black holes, which have no charge or rotation, only mass and spatial dimensions.

–       Star –> supernova explosion –> shed most gases, more than 2.5 solar masses, spacetime only slightly curved         –> gravity overwhelms forces between particles –> star shrinks dramatically and atomic particles are squeezed together (squeezed inside each other) –> curvature of spacetime becomes more pronounced, light rays are deflected from usual path, some returning to the dead star  –> more light pulled back to star, star grows rapidly darker –> all light bends back to star, black hole is formed

–       Star has fallen inside its event horizon when it has contracted so much that nothing can escape

• Event horizon = horizon in the geometry of space and time; a place disconnected from space and time, not part of our universe
• Black holes have a diameter of 30 km per 5-solar-mass

–       There are no forces in nature to support a black hole, so the gravity continues to increase, and it continues to contract

• Singularity: entire star is crushed down to a single point at which there is infinite pressure, infinite density, and infinite curvature of spacetime; every particle of the star is crushed out of existence; heart of the black hole

–       Black hole only has two parts: the singularity, surrounded by the event horizon

• Black hole is empty; does not get full of stuff that is pulled in; the stuff gets pulled in and crushed out of existence

–       Many strange effects of relativity exaggerated near a black hole

• Gravity slows down time –> time stops completely at the event horizon
• Time and space reversed –> on earth you have control over where you move in space, but not over where you move in time; in a black hole, you could move wherever you like in time, but you are pulled in only one direction in space (toward the singularity)

–       “It is important to realize that black holes eat stuff in an unforgiving, irreversible fashion.”  (Kaufmann, 1979)

The Search for Black Holes.

–       Cygnus X-1

• Discovered by x-ray satellite
• Has visible star “companion”
• Stellar winds from companion star get sucked into orbit around X-1 and then begin to spiral in towards the singularity
  • Friction between gas particles (particles moving much faster closer to singularity) creates immense amounts of heat (2 million degrees!); this is what shows up on the x-ray satellite

Einstein’s legacy

–       “There is no such thing as absolute space. There is no such thing as absolute time. Newton’s foundation for all of physics was flawed. And as for the aether: it does not exist.” (Thorne, 1994)

–       The Principle of the Absoluteness of the Speed of Light

• “Space and time must be constituted as to make the speed of  light absolutely the same in all directions, and absolutely independent of the motion of the person who measures it” (Thorne, 1994)

–       The Principle of Relativity

• “Whatever might be their nature, the laws of physics must treat all states of motion on equal footing” (Thorne, 1994)

–       “If you and I move relative to each other, what I call space must be a mixture of your space and time, and what you call space must be a mixture of my space and time.” (Thorne, 1994)

–       Black holes discovered and rejected

• Schwarzschild singularities
  • Schwarzschild geometry
    • Curved (warped) four-dimensional spacetime
    • Gravitational time dilation

–       Einstein did not believe in Schwarzschild singularities (black holes)

• Calculated that if a cluster of particles, with gravity holding them together, were squeezed to 1.5 times their critical circumference (=event horizon), particles would need to move faster than light to escape
  • Since nothing can move faster than light, these things must not exist
    • Did not account for the possibility that things do not escape (even light)
      • “If the object does get that small, then gravity necessarily overwhelms all other forces inside the object, and squeezes the object into a catastrophic implosion, which forms a black hole.” (Thorne, 1994)
        • Einstein rejected the idea of a star imploding, as did most of his colleagues
          • Black holes not taken seriously until 1960s

Sources:

Gribbin, J. (2009). In search of the multiverse: Parallel worlds, hidden dimensions, and the ultimate quest for the frontiers of reality. Hoboken, NJ: John Wiley & Sons, Inc.

Kaku, M. (2008). Physics of the impossible: A scientific exploration into the world of phasers, force fields, teleportation, and time travel. New York: Random House, Inc.

Kaufmann, W. J. III. (1979). Black Holes and Warped Spacetime. San Francisco, CA. W.H. Freeman and Company.

Thorne, K.S. (1994). Black Holes and Time Warps: Einstein’s Outrageous Legacy. New York, NY. W. W. Norton and Company.