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Fun With Optics: Can You Explain How A Telescope Works?

Use simple materials to explore the properties of reflection and refraction as you discover how optics work in telescopes.

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Illuminating Luminescence

Compare and contrast different forms of luminescence by observing how chemiluminescence, phosphorescence, and fluorescence produce or emit light.

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Privacy Overview

This website uses cookies to improve your experience while you navigate through the website. Out of these cookies, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. We also use third-party cookies that help us analyze and understand how you use this website. These cookies will be stored in your browser only with your consent. You also have the option to opt-out of these cookies. But opting out of some of these cookies may have an effect on your browsing experience.

Necessary

Always Enabled

Necessary cookies are absolutely essential for the website to function properly. These cookies ensure basic functionalities and security features of the website, anonymously.

Cookie	Duration	Description
_abck	1 year	This cookie is used to detect and defend when a client attempt to replay a cookie.This cookie manages the interaction with online bots and takes the appropriate actions.
ASP.NET_SessionId	session	Issued by Microsoft's ASP.NET Application, this cookie stores session data during a user's website visit.
AWSALBCORS	7 days	This cookie is managed by Amazon Web Services and is used for load balancing.
bm_sz	4 hours	This cookie is set by the provider Akamai Bot Manager. This cookie is used to manage the interaction with the online bots. It also helps in fraud preventions
cookielawinfo-checkbox-advertisement	1 year	Set by the GDPR Cookie Consent plugin, this cookie is used to record the user consent for the cookies in the "Advertisement" category .
cookielawinfo-checkbox-analytics	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Analytics".
cookielawinfo-checkbox-functional	11 months	The cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional".
cookielawinfo-checkbox-necessary	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookies is used to store the user consent for the cookies in the category "Necessary".
cookielawinfo-checkbox-others	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Other.
cookielawinfo-checkbox-performance	11 months	This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Performance".
csrftoken	past	This cookie is associated with Django web development platform for python. Used to help protect the website against Cross-Site Request Forgery attacks
JSESSIONID	session	The JSESSIONID cookie is used by New Relic to store a session identifier so that New Relic can monitor session counts for an application.
nlbi_972453	session	A load balancing cookie set to ensure requests by a client are sent to the same origin server.
PHPSESSID	session	This cookie is native to PHP applications. The cookie is used to store and identify a users' unique session ID for the purpose of managing user session on the website. The cookie is a session cookies and is deleted when all the browser windows are closed.
TiPMix	1 hour	The TiPMix cookie is set by Azure to determine which web server the users must be directed to.
viewed_cookie_policy	11 months	The cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. It does not store any personal data.
visid_incap_972453	1 year	SiteLock sets this cookie to provide cloud-based website security services.
X-Mapping-fjhppofk	session	This cookie is used for load balancing purposes. The cookie does not store any personally identifiable data.
x-ms-routing-name	1 hour	Azure sets this cookie for routing production traffic by specifying the production slot.

Functional

Functional cookies help to perform certain functionalities like sharing the content of the website on social media platforms, collect feedbacks, and other third-party features.

Cookie	Duration	Description
__cf_bm	30 minutes	This cookie, set by Cloudflare, is used to support Cloudflare Bot Management.
bcookie	2 years	LinkedIn sets this cookie from LinkedIn share buttons and ad tags to recognize browser ID.
bscookie	2 years	LinkedIn sets this cookie to store performed actions on the website.
lang	session	LinkedIn sets this cookie to remember a user's language setting.
lidc	1 day	LinkedIn sets the lidc cookie to facilitate data center selection.
S	1 hour	Used by Yahoo to provide ads, content or analytics.
sp_landing	1 day	The sp_landing is set by Spotify to implement audio content from Spotify on the website and also registers information on user interaction related to the audio content.
sp_t	1 year	The sp_t cookie is set by Spotify to implement audio content from Spotify on the website and also registers information on user interaction related to the audio content.
UserMatchHistory	1 month	LinkedIn sets this cookie for LinkedIn Ads ID syncing.

Performance

Performance cookies are used to understand and analyze the key performance indexes of the website which helps in delivering a better experience for the visitors. They help us to know which pages are the most and least popular and see how visitors move around the site. All information these cookies collect is aggregated and therefore anonymous. If you do not allow these cookies we will not know when you have visited our site, and will not be able to monitor its performance.

Cookie	Duration	Description
__jid	30 minutes	Cookie used to remember the user's Disqus login credentials across websites that use Disqus.
_gat	1 minute	This cookie is installed by Google Universal Analytics to restrain request rate and thus limit the collection of data on high traffic sites.
_gat_UA-28243511-22	1 minute	A variation of the _gat cookie set by Google Analytics and Google Tag Manager to allow website owners to track visitor behaviour and measure site performance. The pattern element in the name contains the unique identity number of the account or website it relates to.
AWSALB	7 days	AWSALB is an application load balancer cookie set by Amazon Web Services to map the session to the target.
countryCode	session	This cookie is used for storing country code selected from country selector.

Audience Measurement

Advertisement cookies are used to provide visitors with relevant ads and marketing campaigns. These cookies track visitors across websites and collect information to provide customized ads.

Cookie	Duration	Description
_fbp	3 months	This cookie is set by Facebook to display advertisements when either on Facebook or on a digital platform powered by Facebook advertising, after visiting the website.
fr	3 months	Facebook sets this cookie to show relevant advertisements to users by tracking user behaviour across the web, on sites that have Facebook pixel or Facebook social plugin.
IDE	1 year 24 days	Google DoubleClick IDE cookies are used to store information about how the user uses the website to present them with relevant ads and according to the user profile.
NID	6 months	NID cookie, set by Google, is used for advertising purposes; to limit the number of times the user sees an ad, to mute unwanted ads, and to measure the effectiveness of ads.
personalization_id	2 years	Twitter sets this cookie to integrate and share features for social media and also store information about how the user uses the website, for tracking and targeting.
test_cookie	15 minutes	The test_cookie is set by doubleclick.net and is used to determine if the user's browser supports cookies.
vglnk.Agent.p	1 year	VigLink sets this cookie to track the user behaviour and also limit the ads displayed, in order to ensure relevant advertising.
vglnk.PartnerRfsh.p	1 year	VigLink sets this cookie to show users relevant advertisements and also limit the number of adverts that are shown to them.
VISITOR_INFO1_LIVE	5 months 27 days	A cookie set by YouTube to measure bandwidth that determines whether the user gets the new or old player interface.
YSC	session	YSC cookie is set by Youtube and is used to track the views of embedded videos on Youtube pages.
yt-remote-connected-devices	never	YouTube sets this cookie to store the video preferences of the user using embedded YouTube video.
yt-remote-device-id	never	YouTube sets this cookie to store the video preferences of the user using embedded YouTube video.
yt.innertube::nextId	never	This cookie, set by YouTube, registers a unique ID to store data on what videos from YouTube the user has seen.
yt.innertube::requests	never	This cookie, set by YouTube, registers a unique ID to store data on what videos from YouTube the user has seen.

Others

Other uncategorized cookies are those that are being analyzed and have not been classified into a category as yet.

Cookie	Duration	Description
_dc_gtm_UA-28243511-20	1 minute	No description
abtest-identifier	1 year	No description
AnalyticsSyncHistory	1 month	No description
ARRAffinityCU	session	No description available.
ccc	1 month	No description
COMPASS	1 hour	No description
cookies.js_dtest	session	No description
debug	never	No description available.
donation-identifier	1 year	No description
f	never	No description available.
GFE_RTT	5 minutes	No description available.
incap_ses_1185_2233503	session	No description
incap_ses_1185_823975	session	No description
incap_ses_1185_972453	session	No description
incap_ses_1319_2233503	session	No description
incap_ses_1319_823975	session	No description
incap_ses_1319_972453	session	No description
incap_ses_1364_2233503	session	No description
incap_ses_1364_823975	session	No description
incap_ses_1364_972453	session	No description
incap_ses_1580_2233503	session	No description
incap_ses_1580_823975	session	No description
incap_ses_1580_972453	session	No description
incap_ses_198_2233503	session	No description
incap_ses_198_823975	session	No description
incap_ses_198_972453	session	No description
incap_ses_340_2233503	session	No description
incap_ses_340_823975	session	No description
incap_ses_340_972453	session	No description
incap_ses_374_2233503	session	No description
incap_ses_374_823975	session	No description
incap_ses_374_972453	session	No description
incap_ses_375_2233503	session	No description
incap_ses_375_823975	session	No description
incap_ses_375_972453	session	No description
incap_ses_455_2233503	session	No description
incap_ses_455_823975	session	No description
incap_ses_455_972453	session	No description
incap_ses_8076_2233503	session	No description
incap_ses_8076_823975	session	No description
incap_ses_8076_972453	session	No description
incap_ses_867_2233503	session	No description
incap_ses_867_823975	session	No description
incap_ses_867_972453	session	No description
incap_ses_9117_2233503	session	No description
incap_ses_9117_823975	session	No description
incap_ses_9117_972453	session	No description
li_gc	2 years	No description
loglevel	never	No description available.
msToken	10 days	No description